MOTORIZED WINDOW TREATMENT
20170260806 · 2017-09-14
Assignee
Inventors
- Jason O. Adams (Emmaus, PA, US)
- Edward J. Blair (Telford, PA, US)
- Andrew Karl Cooney (Quakertown, PA, US)
- Soumya Jain (Maharashta, IN)
- David A. Kirby (Zionsville, PA, US)
- Stephen Lundy (Coopersburg, PA)
- Justin J. Mierta (Allentown, PA, US)
- Daniel W. Mistarz (Allentown, PA, US)
- Robert C. Newman, Jr. (Emmaus, PA)
- Peter W. Ogden (Breinigsville, PA, US)
- Jonathan L. Roe (Coopersburg, PA, US)
- Chen Ming Wu (Emmaus, PA, US)
- Justin M. Zernhelt (New York, NY, US)
Cpc classification
E06B9/72
FIXED CONSTRUCTIONS
H04W52/0277
ELECTRICITY
E06B9/42
FIXED CONSTRUCTIONS
Y02B80/00
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
E06B2009/6872
FIXED CONSTRUCTIONS
H04W52/0238
ELECTRICITY
Y02D30/70
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H04W52/0287
ELECTRICITY
E06B9/70
FIXED CONSTRUCTIONS
Y02A30/24
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
E06B9/322
FIXED CONSTRUCTIONS
H04W52/028
ELECTRICITY
E06B9/68
FIXED CONSTRUCTIONS
E06B2009/2625
FIXED CONSTRUCTIONS
International classification
Abstract
A motorized window treatment provides a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment includes a covering material, a drive shaft, at least one lift cord rotatably received around the drive shaft and connected to the covering material, and a motor coupled to the drive shaft for raising and lowering the covering material. The window treatment also includes a spring assist unit for assisting the motor by providing a torque that equals the torque provided by the weight on the cords that lift the covering material at a position midway between fully-open and fully-closed positions, which helps to minimize motor usage and conserve battery life if a battery is used to power the motorized window treatment. The window treatment may comprise a photosensor for measuring the amount of daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window. The position of the covering material may be automatically controlled in response to the photosensor and the temperature sensors to save energy, or may also be controlled in response to an infrared or radio-frequency remote control.
Claims
1. A motorized window treatment comprising: a covering material; a drive shaft; at least one lift cord rotatably received around the drive shaft and arranged to extend to a bottom end of the covering material in such a way that the lift cord provides a torque on the drive shaft; a motor drive unit having a motor coupled to the drive shaft and configured to rotate the drift shaft to raise and lower the covering material; and a spring assist assembly coupled to the drive shaft and configured to provide torque on the drive shaft in a direction opposite a direction of the torque provided on the drive shaft by the lift cord; wherein an amount of energy required by the motor to drive the drive shaft is reduced by the spring assist assembly.
2. The motorized window treatment of claim 1, wherein the motor drive unit is configured to rotate the drift shaft to raise and lower the covering material between a fully-open position and a fully-closed position; and wherein the constant amount of torque provided by the spring assist assembly is approximately equal to the torque provided on the drive shaft by the at least one lift cord when the bottom end of the covering material is positioned half-way between the fully-open position and the fully-closed position.
3. The motorized window treatment of claim 2, wherein an amount of energy required by the motor to drive the drive shaft is reduced by the spring assist assembly such that net energy is provided by the motor to raise the covering material during approximately half the distance between the fully-closed and fully-open position.
4. The motorized window treatment of claim 3, wherein net energy is provided by the motor when the covering material is raised between half-way and the fully-open position and when the covering material is lowered between half-way and the fully-closed position.
5. The motorized window treatment of claim 1, further comprising: at least a first compartment and a second compartment configured to hold respective first and second batteries for powering the motor drive unit, the first and second compartments located on each side of the motor drive unit.
6. The motorized window treatment of claim Error! Reference source not found, wherein the motor drive unit further comprises a rotational position sensor coupled to the drive shaft for sensing movement of the drive shaft and for determining the position of a bottom of the covering material.
7. The motorized window treatment of claim 6, wherein the covering material is engageable by a user to manually adjust the covering material, the motor drive unit operable to determine the position of the covering material in response to the covering material being manually adjusted.
8. The motorized window treatment of claim 1, wherein the motor drive unit further comprises an RF receiver configured to receive a radio-frequency (RF) signals, and wherein the motor drive unit is further configured to rotate the drift shaft to raise and lower the covering material in response to received RF signals.
9. The motorized window treatment of claim 8, wherein the controller comprises a microprocessor configured to receive signals from the RF receiver and to control the RF receiver, the processor configured to control the RF receiver to at least one of place the RF receiver in a low power mode and turn the RF receiver off to conserve battery power.
10. The motorized window treatment of claim 1, wherein the motor drive unit further comprises an RF transceiver configured to transmit and receive radio-frequency (RF) signals, and wherein the motor drive unit is further configured to rotate the drift shaft to raise and lower the covering material in response to received RF signals.
11. The motorized window treatment of claim 1, wherein the spring assist assembly comprises a constant-force spring configured to provide a constant torque on the drive shaft in a direction opposite a direction of the torque provided on the drive shaft by the lift cord.
12. The motorized window treatment of claim 1, wherein the spring assist assembly comprises a negative-gradient spring configured to provide a varying torque on the drive shaft in a direction opposite a direction of the torque provided on the drive shaft by the lift cord
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The invention will now be described in greater detail in the following detailed description with reference to the drawings in which:
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DETAILED DESCRIPTION OF THE INVENTION
[0074] The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment that is presently preferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed.
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[0080] The gear assembly 185 further comprises a first roller 199A (
[0081] The battery-powered motorized window treatment 110 also comprises a plurality of batteries 138 (e.g., four D-cell batteries), which are electrically coupled in series. The series-combination of the batteries 138 is coupled to the motor drive unit 120 for powering the motor drive unit. The batteries 138 are housed inside the headrail 114 and thus out of view of a user of the motorized window treatment 110. Specifically, the batteries 138 are mounted in two battery holders 139 located inside the headrail 114, such that there are two batteries in each battery holder as shown in
[0082] To provide for easy access to the batteries 138 to allow the user to change the batteries when needed, the motorized window treatment 110 is operable to be adjusted to a service position.
[0083] When the batteries 138 need to be accessed, the headrail 114 may be lifted up by a user, such that the screws 144 are no longer positioned in the respective ends 146 and may travel through the channels 142 as shown in
[0084] Accordingly, the headrail 114 is adapted to moved down and away from the window 104 and into the service position, so that the headrail may then be tilted to allow the user to access the batteries 138. Since the headrail 114 is moved horizontally away from the window 104 when in the service position, there is room between the headrail and the window in which the shade fabric 112 may be located when the top of the headrail 114 is rotated towards the user.
[0085] According to the first embodiment of the present invention, the spring assist assemblies 135 are coupled to the drive shafts 132 with one of the spring assist assemblies housed in each of the lift cord spool enclosures 136 as shown in
[0086]
[0087] With reference to
[0088] When the weighting element 116 is in the fully-open position P.sub.FULLY-OPEN, the spring assist assemblies 135 provide a constant torque to raise the cellular shade fabric 112, opposed by the increasing torque provided by the weight of the cellular shade fabric as the weighting element 116 pushes against the cellular shade fabric that piles up on the weighting element 116. At a point approximately at the position at the middle of the fully-open position P.sub.FULLY-OPEN and the fully-closed position P.sub.FULLY-CLOSED, the torque provided by the spring assist assembly 138 balances the torque provided by the lift cords 130 which is shown at the 50% position in
[0089]
[0090] In
[0091] Alternatively, each spring assist assembly 135 could include a negative-gradient spring (not shown) coupled between the respective lift cord spool enclosure 136 and the respective drive shaft 132. Each negative-gradient spring provides a varying torque on the respective drive shaft 132 depending upon the position of the cellular shade fabric 112, for example, to provide more torque when the cellular shade fabric 112 is close to or at the fully-open position P.sub.FULLY-OPEN than when the cellular shade fabric is close to or at the fully-closed position P.sub.FULLY-CLOSED. Similar to torque plots for the constant-force spring as shown in
[0092]
[0093] The controller 152 is coupled to an H-bridge motor drive circuit 154 for driving the motor 150 via a set of drive signals V.sub.DRIVE to control the weighting element 116 and the cellular shade fabric 112 between the fully-open position P.sub.FULLY-OPEN and the fully-closed position P.sub.FULLY-CLOSED. As previously mentioned, the motor drive unit 120 receives power from the series-coupled batteries 138, which provide a battery voltage V.sub.BATT. For example, the batteries 138 may comprise D-cell batteries having rated voltages of approximately 1.5 volts, such that the battery voltage V.sub.BATT has a magnitude of approximately 6 volts. The battery voltage V.sub.BATT is electrically coupled to the circuitry of the motor drive unit 120 through a positive temperature coefficient (PTC) thermistor 155, which produces a battery input voltage V.sub.B-IN that is received by the H-bridge motor drive circuit 154 for driving the motor 150. The PTC thermistor 155 operates to limit the magnitude of the current drawn by the circuitry of the motor drive unit 120 from the batteries 138, and to protect the circuitry of the motor drive unit in the event of a voltage miswire at the battery terminals.
[0094] The controller 152 is operable to rotate the motor 150 at a constant rotational speed by controlling the H-bridge motor drive circuit 154 to supply a pulse-width modulated (PWM) drive signal having a constant frequency (e.g., approximately 20 kHz) and a substantially constant duty cycle (e.g., approximately 25-50%) to the motor. The controller 152 is able to change the rotational speed of the motor 150 by adjusting the duty cycle of the PWM signal applied to the motor and to change the direction of rotation of the motor by changing the polarity of the PWM drive signal applied to the motor. When first starting up the motor 150 to move the bottom bar 116 from a stopped position, the controller 152 is operable to adjust the duty cycle of the PWM signal to ramp up the current drawn from the batteries 138 by the H-bridge motor drive circuit 154 from zero amps until the motor 150 is rotating at the desired constant rotational speed over a ramp time period T.sub.RAMP. The ramp time period T.sub.RAMP allows chemical reactions in the batteries 138 to stabilize before the motor 150 draws large amounts of current from the batteries. The batteries 138 may conduct high-magnitude pulses of current if the motor 150 is simply turned on at the constant rotational speed without the ramp time T.sub.RAMP, i.e., before the chemical reactions in the batteries are allowed to stabilize.
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[0096] Referring back to
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[0098] The controller 152 stores the present position P.sub.PRES of the weighting element 116 in the memory as a number of optical sensors edges between the present position P.sub.PRES of the weighting element and the fully-open position P.sub.FULLY-OPEN. An optical sensor edge is, for example, the low-to-high transition 179 of the first output signal 176 as shown in
[0099] Referring back to
[0100] Once the controller 152 wakes up in response to the manual movement wake-up signal V.sub.MAN.sub._.sub.WAKE, the controller 152 monitors the output of the transmissive optical sensor circuit 156 to track the position of the motor 150 by executing a transmissive optical sensor edge procedure 200, which will be discussed in greater detail below with reference to
[0101]
[0102] A user of the window treatment system 100 is able to adjust the position of the weighting element 116 and the cellular shade fabric 112 by using the remote control 118 to transmit commands to the motor drive unit 120 via the IR signals. Referring back to
[0103] If the limits (i.e., the fully open position P.sub.FULLY-OPEN and the fully closed position P.sub.FULLY-CLOSED) stored in the memory are incorrect, the controller 152 may attempt to drive the motor 150 to move the bottom bar 116 beyond a position that is mechanically allowable. If the movement of the bottom bar 116 is stopped by mechanical constraints before the controller 150 stops driving the motor 150, the motor 150 will drawn a large slug of current from the batteries 138 before the controller 150 notices that the bottom bar 116 has stopped moving and stops driving the motor 150. The PTC thermistor 155 limits the magnitude of the current drawn from the batteries 138 if the fully open position P.sub.FULLY-OPEN and the fully closed position P.sub.FULLY-CLOSED stored in the memory are incorrect. For example, the energy used to raise the bottom bar 116 from the fully closed position P.sub.FULLY-CLOSED to the fully open position P.sub.FULLY-OPEN may be approximately 78 Joules when the limits are set correctly resulting in a lifetime of the batteries of approximately 3 years (assuming that the cellular shade fabric 112 is moved twice a day). When the limits are set incorrectly and the PTC thermistor 155 limits the magnitude of the current drawn from the batteries 138, the energy used to raise the bottom bar 116 from the fully closed position P.sub.FULLY-CLOSED to the fully open position P.sub.FULLY-OPEN may be approximately 83 Joules resulting in a lifetime of the batteries of approximately 2.9 years. However, if the PTC thermistor 155 is not included in the motor drive unit 120 and the limits are set incorrectly, the energy used to raise the bottom bar 116 from the fully closed position P.sub.FULLY-CLOSED to the fully open position P.sub.FULLY-OPEN may be approximately 103 Joules resulting in a lifetime of the batteries 138 of approximately 2.5 years.
[0104] The motor drive unit 120 further comprises a power supply 157 (e.g., a linear regulator or a low quiescent current switching mode supply) that receives the battery input voltage V.sub.B-IN and generates a DC supply voltage V.sub.CC for powering the controller 152 and other low-voltage circuitry of the motor drive unit. The controller 152 is coupled to the power supply 157 and generates a voltage adjustment control signal V.sub.ADJ for adjusting the magnitude of the DC supply voltage V.sub.CC between a first nominal magnitude (e.g., approximately 2.7 volts) and a second increased magnitude (e.g., approximately 3.3 volts). The power supply 157 may comprise, for example, an adjustable linear regulator (or a switching mode supply) having one or more feedback resistors that are switched in and out of the circuit by the controller 152 to adjust the magnitude of the DC supply voltage V.sub.CC. The controller 152 may adjust the magnitude of the DC supply voltage V.sub.CC to the second increased magnitude while the controller is driving the FETs Q.sub.1-Q.sub.4 of the motor drive circuit 154 to rotate the motor 150 (since the controller may require an increased supply voltage to drive the gates of the FETs). The controller 152 adjusts the magnitude of the DC supply voltage V.sub.CC to the first nominal magnitude when the controller is not controlling the motor drive circuit 154 to rotate the motor 150 (e.g., when the controller is in the sleep mode). The magnitude of the idle currents drawn by the controller 152, the IR receiver 166, and other low-voltage circuitry of the motor drive unit 120 may be significantly smaller when these circuits are powered by the first nominal magnitude of the DC supply voltage V.sub.CC.
[0105] The motor drive unit 120 further comprises a battery monitoring circuit 158 that receives the battery input voltage V.sub.B-IN and provides a battery-monitor control signal V.sub.MON representative of the magnitude of the battery voltage V.sub.BATT to the controller 152. The battery monitoring circuit 158 may comprise for example a resistive voltage divider circuit (not shown) coupled in series between the battery input voltage V.sub.B-IN and circuit common, such that the battery-monitor control signal V.sub.MON is simply a scaled version of the battery voltage V.sub.BATT. The controller 152 may include an analog-to-digital converter (ADC) for receiving and measuring the magnitude of the battery-monitor control signal V.sub.MON to thus determine the magnitude of the battery voltage V.sub.BATT. The battery monitoring circuit 158 may further comprise a controllable switch, e.g., a NPN bipolar junction transistor (not shown), coupled in series with the resistive divider. The controller 152 may be operable to render the controllable switch conductive, such that the battery-monitor control signal V.sub.MON is representative of the magnitude of the battery voltage V.sub.BATT, and to render the controllable switch non-conductive, such that the resistive divider does not conduct current and energy is conserved in the batteries 138.
[0106] According to an aspect of the present invention, the controller 152 is operable to determine that the magnitude of the battery voltage V.sub.BATT is getting low in response to the battery-monitor control signal V.sub.MON received from the battery monitoring circuit 158. Specifically, the controller 152 is operable to operate in a low-battery mode when the magnitude of the battery voltage V.sub.BATT drops below a first predetermined battery-voltage threshold V.sub.B-TH1 (e.g., approximately 1.0 volts per D-cell battery). The controller 152 may be operable to recall the number of batteries 138 from memory for determining the value of the first predetermined battery-voltage threshold V.sub.B-TH1. The controller 152 may control the motor drive circuit 154 so that the motor 150 is operated at a reduced speed (e.g., at half speed) to reduce the instantaneous power requirements on the batteries 138 when the controller 152 is operating in the low-battery mode. This would serve as an indication to a consumer that the battery voltage V.sub.BATT is low and the batteries 138 need to be changed.
[0107] When the magnitude of the battery voltage V.sub.BATT drops below a second predetermined battery-voltage threshold V.sub.B-TH2 (less than the first predetermined battery-voltage threshold V.sub.B-TH1, e.g., approximately 0.9 V per battery) while operating in the low-battery mode, the controller 152 may shut down electrical loads in the motor drive unit 120 (e.g., by disabling the IR receiver 166 and other low-voltage circuitry of the motor drive unit) and prevent movements of the cellular shade fabric 112 except to allow for at least one additional movement of the cellular shade fabric to the fully-open position P.sub.FULLY-OPEN. Having the cellular shade fabric 112 at the fully-open position P.sub.FULLY-OPEN allows for easy replacement of the batteries. The second predetermined battery-voltage threshold V.sub.B-TH2 may be sized to provide enough reserve energy in the batteries 138 to allow for the at least one additional movement of the cellular shade fabric 112 and the weighting element 116 to the fully-open position P.sub.FULLY-OPEN.
[0108] When the magnitude of the battery voltage V.sub.BATT drops below a third predetermined battery-voltage threshold V.sub.B-TH3 (less than the second predetermined battery-voltage threshold V.sub.B-TH2, e.g., approximately 0.8 V per battery), the controller 152 may be operable to shut itself down (e.g., to hibernate) such that the circuitry of the motor drive unit 120 draws a minimal amount of current from the batteries 138 in order to protect against any potential leakage of the batteries.
[0109] Referring back to
[0110] These embodiments allow the motor drive unit 120 to keep track of the position of the weighting element 116 of the window treatment 110 even when the batteries 138 are removed and the window treatment is manually operated (i.e., pulled). In such embodiments, the controller 152 continues to receive signals from transmissive optical sensor circuit 156, even when the batteries 138 are removed. Because it remains powered, the controller 152 will continue to calculate the position of the window treatment 110 when manually adjusted. It should be pointed out that the window treatment 110 of the present invention allows a user at any time to manually adjust the position of the window treatment, and that the position of the window treatment is always calculated both when the window treatment is moved by the motor or manually.
[0111] Another feature of the invention is that the controller 152 is preferably arranged to prevent the motor drive circuit 154 from operating to lower the cellular shade fabric 112 until an upper limit for the fabric is reset after a loss of power, e.g., if the batteries 138 are depleted. Thus, the motor drive unit 120 will not lower from the current raised position in the event of power loss. The user will be required to raise the cellular shade fabric 112 to the fully-open position before being able to lower the shade fabric.
[0112] As shown in
[0113] The controller 152 receives inputs from the internal temperature sensor 160, the external temperature sensor 162, and the photosensor 164. The controller 152 may operate in an eco-mode to control the position of the weighting element 116 and the cellular shade fabric 112 in response to the internal temperature sensor 160, the external temperature sensor 162, and the photosensor 164, so as to provide energy savings. When operating in the eco-mode, the controller 152 adjusts the amount of the window 104 covered by the cellular shade fabric 112 to attempt to save energy, for example, by reducing the amount of electrical energy consumed by other control systems in the building in which the motorized window treatment 110 is installed. For example, the controller 152 may adjust the present position P.sub.PRES of the weighting element 116 to control the amount of daylight entering the room in which the motorized window treatment 110 is installed, such that lighting loads in the room may be turned off or dimmed to thus save energy. In addition, the controller 152 may adjust the present position P.sub.PRES of the weighting element 116 to control the heat flow through the window 104 in order to lighten the load on a heating and/or cooling system, e.g., a heating, air-conditioning, and ventilation (HVAC) system, in the building in which the motorized window treatment 110 is installed.
[0114] The controller 152 is coupled to the actuator 126 for receiving user inputs in response to actuations of the actuator 126. The controller 152 is further coupled to a light-emitting diode (LED) 168 for illumination the actuator 126 to thus provide feedback, for example, during configuration of the motorized window treatment 110 or if the battery voltage V.sub.BATT is low.
[0115] The IR remote control 118 is operable to transmit a predetermined number of packets (i.e., digital messages), for example, approximately six packets, to the motor drive unit 120 via the IR signals in response to an actuation of an actuator of the remote control. Each of the digital messages transmitted by the remote control 118 is encoded using Manchester encoding.
[0116] As previously mentioned, the controller 152 generates the IR enable control signal V.sub.IR-EN for enabling and disabling the IR receiver 166. When the IR remote control 118 is not presently transmitting IR signals to the IR receiver 166, the controller 152 operates the IR receiver in a sleep mode to conserve battery power. In the sleep mode, the IR receiver 166 is disabled for most of the time and is periodically enabled for short periods of time to determine if the IR remote control 118 has begun transmitting IR signals.
[0117] Since the IR remote control 118 transmits the digital messages using Manchester encoding, there is guaranteed to be at least one “low-to-high” or “high-to-low” transition during each bit time period T.sub.BIT-IR of the Manchester-encoded digital message 250 when the IR remote control 118 is transmitting IR signals to the IR receiver 166. Therefore, the sample time period T.sub.SMPL-IR of the IR enable control signal V.sub.IR-EN during the sleep mode can be sized to be as small as the bit time period T.sub.BIT-IR of the Manchester-encoded digital message 250 (i.e., approximately 900 μsec).
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[0121] If the motor 150 is presently rotating at step 510, but the present position P.sub.PRES is not yet equal to the target position P.sub.TARGET at step 516, the controller 512 continues to drive the motor 150 appropriately at step 518 and the motor control procedure 500 exits. If the motor 150 is presently rotating at step 510 and the present position P.sub.PRES is now equal to the target position P.sub.TARGET at step 516, the controller 152 stops driving the motor at step 520 and controls the voltage adjustment control signal V.sub.ADJ to adjust the magnitude of the DC supply voltage V.sub.CC to the nominal magnitude (i.e., approximately 2.7 volts) at step 522. The controller 152 then waits for a timeout period (e.g., approximately 200 msec) at step 524, and puts the IR receiver 166 back to sleep at step 525.
[0122] As previously mentioned, the controller 152 operates in a low-battery mode when the magnitude of the battery voltage V.sub.BATT is getting low. Specifically, if the magnitude of the battery voltage V.sub.BATT has dropped below the first battery-voltage threshold V.sub.B-TH1 at step 526, the controller 152 begins at step 528 to operate in the low-battery mode during which the controller 152 will operate the motor at a reduced speed (i.e., at half speed). If the magnitude of the battery voltage V.sub.BATT is less than or equal to the second battery-voltage threshold V.sub.B-TH2 at step 530, the controller 152 allows for one last movement of the cellular shade fabric 112 and the weighting element 116 to the fully-open position P.sub.FULLY-OPEN by setting a FINAL_MOVE flag in memory at step 532. At step 534, the controller 152 shuts down all unnecessary loads of the motor drive unit 120 (e.g., the external temperature sensor 162, the photosensor 164, the internal temperature sensor 160, and the IR receiver 166) and prevents the motor 150 from moving the cellular shade fabric 112 and the weighting element 116 except for one last movement to the fully-open position P.sub.FULLY-OPEN. If the magnitude of the battery voltage V.sub.BATT is less than or equal to the third battery-voltage threshold V.sub.B-TH3 at step 536, the controller 152 shuts itself down at step 538 such that no other circuits in the motor drive unit 120 consume any power to thus protect against any potential leakage of the batteries 138. Otherwise, the motor control procedure 500 exits.
[0123] According to an alternate embodiment of the present invention, the controller 152 is operable to monitor the magnitude of the battery voltage V.sub.BATT while the controller is driving the H-bridge drive circuit 154 to rotate the motor 150. Since the batteries 138 are each characterized by an equivalent series resistance (ESR), the magnitude of the battery voltage V.sub.BATT will be the lowest magnitude when the motor 150 is rotating and drawing a maximum amount of current (i.e., a peak current) from the batteries. According to the alternate embodiment, the controller 152 only compares the magnitude of the battery voltage V.sub.BATT to a single battery-voltage threshold V.sub.B-TH (e.g., approximately 0.8 volt per battery). When the magnitude of the battery voltage V.sub.BATT drops below the battery-voltage threshold V.sub.B-TH for the first time while the controller 152 is driving the motor 150 (i.e., when the controller is operating in a normal mode of operation), the controller then begins operating in a first low-battery mode during which the controller rotates the motor at a reduced speed (e.g., at half speed). Accordingly, the motor 150 will draw less current from the batteries 138 in the first low-battery mode and the magnitude of the battery voltage V.sub.BATT will recover, i.e., increase back up above the battery-voltage threshold V.sub.B-TH.
[0124] When the magnitude of the battery voltage V.sub.BATT drops below the battery-voltage threshold V.sub.B-TH again, i.e., while the controller 152 is driving the motor 150 in the first low-battery mode, the controller begins operating in a second low-battery mode during which the controller 152 stops driving the motor 150 and simply blinks the LED 168 (and thus the actuator 126) to provide feedback to the user that the battery voltage V.sub.BATT is low. Once again, the battery voltage V.sub.BATT will recover and rise above the battery-voltage threshold V.sub.B-TH. When the magnitude of the battery voltage V.sub.BATT drops below the battery-voltage threshold V.sub.B-TH while in the second low-battery mode, the controller 152 enters a third low battery mode in which the controller hibernates (e.g., shuts down), such that the circuitry of the motor drive unit 120 draws a minimal amount of current from the batteries 138 and the batteries are protected against potential leakage.
[0125] Because the controller 152 is monitoring the magnitude of the battery voltage V.sub.BATT while the H-Bridge drive circuit 154 is driving the motor 150 with the PWM signal at the constant frequency (i.e., approximately 20 kHz), a low-pass filter circuit is coupled between the output of the battery monitoring circuit 158 and the controller 152 according to the alternate embodiment to thus smooth out the 20-kHz ripple on the battery voltage V.sub.BATT. In addition, the controller 152 may be operable to sample the filtered battery-monitor control signal V.sub.MON at a sampling period (e.g., approximately 3 μsec) to collect a predetermined number of samples (e.g., approximately 16 samples) and then average the predetermined number of samples to generate a battery voltage sample that may be compared to the battery-voltage threshold V.sub.B-TH.
[0126]
[0127] If the motor 150 is presently rotating at step 560, but the present position P.sub.PRES is not yet equal to the target position P.sub.TARGET at step 568, the controller 512 continues to drive the motor 150 appropriately at step 570. The controller 152 then compares the magnitude of the battery voltage V.sub.BATT (i.e., the generated battery voltage sample) to the battery-voltage threshold V.sub.B-TH at step 572. If the magnitude of the battery voltage V.sub.BATT is less than or equal to the battery-voltage threshold V.sub.B-TH at step 572 and the controller 152 is operating in the normal mode at step 574, the controller begins operating in the first low-battery mode at step 576 during which the controller operates the motor 150 at a reduced speed (i.e., at half speed). If the controller 152 is not operating in the normal mode at step 574, but is operating in the first low-battery mode at step 578, the controller begins operating in the second low-battery mode at step 580 during which the controller stops driving the motor 150. The controller 152 then begins to blink the LED 168 and the actuator 126 to provide feedback that the battery voltage V.sub.BATT is low at step 582, and the motor control procedure 500 exits.
[0128] When the present position P.sub.PRES becomes equal to the target position P.sub.TARGET at step 568, the controller 152 stops driving the motor at step 584 and controls the voltage adjustment control signal V.sub.ADJ to adjust the magnitude of the DC supply voltage V.sub.CC to the nominal magnitude at step 586. The controller 152 then waits for a timeout period (e.g., approximately 200 msec) at step 588, and puts the IR receiver 166 to sleep at step 590. If the motor 150 is not presently rotating at step 560 and the present position P.sub.PRES is equal to the target position P.sub.TARGET at step 562, the controller 152 monitors the magnitude of the battery voltage V.sub.BATT when the controller is operating in the second low-battery mode at step 592. If the magnitude of the battery voltage V.sub.BATT is less than or equal to the battery-voltage threshold V.sub.B-TH at step 594 when the controller is operating in the second low-battery mode at step 592, the controller 152 begins to operate in the third low-battery mode at step 596 and shuts down (i.e., hibernates) at step 598, such that the circuitry of the motor drive unit 120 draws a minimal amount of current from the batteries 138 and the batteries are protected against potential leakage. While the controller 152 checks the to see if the magnitude of the battery voltage V.sub.BATT is less than or equal to the battery-voltage threshold V.sub.B-TH every time that the motor control procedure 550 is executed (e.g., every two msec) when the controller is operating in the second low-battery mode, the controller 152 could alternatively monitor the magnitude of the battery voltage V.sub.BATT in the second low-battery mode as part of a separate procedure that may be executed less often, for example, every hour.
[0129]
[0130] If the controller 152 determines that the present time is daytime at step 610, the controller 512 then determines the present time of year at step 614, for example, by determining if the present time of year is summer or winter. The controller 152 may be operable to determine the length of daylight (e.g., the time each day that the light intensity measured by the photosensor 164 exceeds the nighttime intensity threshold) and to compare the determined length of daylight to data representing typical day lengths, e.g., data from the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE).
[0131] The controller 152 is further able to determine at step 616 if heat is flowing through the window 104 into the room or out of the room by comparing the exterior temperature T.sub.EXT measured by the external temperature sensor 162 to the interior temperature T.sub.INT measured by the room-side temperature sensor 160. For example, if the exterior temperature T.sub.ENT is greater than the interior temperature T.sub.INT, the controller 152 may determine that heat is flowing into the room through the window 104. If the exterior temperature T.sub.ENT is less than the interior temperature T.sub.INT, the controller 152 may determine that heat is flowing out of the window 104.
[0132] If the present time of year is summer at step 614 and heat is flowing into the room through the window 104 at step 616, the controller 152 sets the target position P.sub.TARGET equal to the fully-closed position P.sub.FULLY-CLOSED at step 612 to close the motorized window treatment 110 and prevent the sunlight from heating the room. If the present time of year is summer at step 614 and heat is flowing out of the window 104 at step 616, the controller 152 sets the target position P.sub.TARGET equal to the fully-open position P.sub.FULLY-OPEN at step 618 to open the motorized window treatment 110 to take advantage of the daylight, such that the lighting loads in the room may be turned off or dimmed. If the present time of year is winter at step 614 and heat is flowing into the room through the window 104 at step 620, the controller 152 opens the motorized window treatment 110 at step 618 to allow the sunlight to heat the room. If the present time of year is winter at step 614 and heat is flowing out of the window 104 at step 620, the controller 152 closes the motorized window treatment 110 at step 622 to insulate the room and prevent heat from flowing out the room.
[0133]
[0134] Alternatively, the motor drive unit 120 may not comprise the internal temperature sensor 160, but could simply assume that the internal temperature T.sub.INT inside the room is a predetermined room temperature (e.g., approximately 22° C.).
[0135] The IR receiver 166 could alternatively comprise a radio-frequency (RF) receiver or transceiver for receiving RF signals transmitted by an RF remote control.
[0136]
[0137]
[0138] Referring back to
[0139] According to the second embodiment of the present invention, the motorized window treatment 710 and the RF remote control 718 may be easily programmed, such that the motorized window treatment 710 is responsive to actuations of the buttons 790-798 of the remote control 718. First, the user may associate the remote control 718 with the motorized window treatment 710 by actuating the actuator 126 on the motor drive unit 720 and then pressing and holding, for example, the close button 792 on the remote control for a predetermined amount of time (e.g., approximately five seconds). After the remote control 718 is associated with the motorized window treatment 710, the motorized window treatment is responsive to the RF signals 706 transmitted by the remote control. The user may program the preset position P.sub.PRESET of the motorized window treatment 710 by actuating the raise and lower buttons 794, 796 of the remote control 718 to adjust the position of the weighting element 116 to the desired preset position, and then pressing and holding the preset button 798 for the predetermined amount of time.
[0140] The user may also use the remote control 718 to program the upper and lower limits (i.e., the fully-open position P.sub.FULLY-OPEN and the fully-closed position P.sub.FULLY-CLOSED) of the motorized window treatments 710. To enter a limit programming mode, the user actuates the actuator 126 on the motor drive unit 720, and then simultaneously presses and holds the open button 790 and the raise button 794 of the remote control 718 for the predetermined amount of time (i.e., approximately five seconds). To program the lower limit, the user actuates the raise and lower buttons 794, 796 of the remote control 718 to adjust the position of the weighting element 116 to the desired fully-closed position P.sub.FULLY-CLOSED, and then presses the close button 792 for the predetermined amount of time. To program the upper limit, the user actuates the raise and lower buttons 794, 796 of the remote control to adjust the position of the weighting element 116 to the desired fully-open position P.sub.FULLY-OPEN, and then presses the open button 794 for the predetermined amount of time. The user can then press and hold the open button 790 and the raise button 794 of the remote control 718 for the predetermined amount of time to exit the limit programming mode.
[0141] The RF receiver 766 and the controller 752 are both able to operate in a sleep mode (i.e., low-power mode) to conserve battery power. During the sleep mode, the RF receiver 766 is operable to wake-up periodically to sample (e.g., listen for) any RF signals 706 as will be described in greater detail below. In the event that the RF receiver 766 does detect the presence of any RF signals 706, the RF receiver is operable to wake up the controller 752 via an RF wake up signal V.sub.RF.sub._.sub.WAKE, such that the controller can begin processing the received RF signal. In particular, the RF receiver 766 wakes up the controller 752 in response to detecting any RF energy within a particular frequency band. Each time that the controller 752 wakes up in response to the RF wake up signal V.sub.RF.sub._.sub.WAKE, additional power is consumed by the controller (since the controller is fully powered when awake). This additional power consumption reduces the life of the batteries 738B, and as a result, it is optimal that the RF receiver 766 only wake the controller 752 when necessary.
[0142]
[0143]
[0144] The RF sample time period T.sub.SMPL-RF and the RF sleep time period T.sub.SLP-RF of the RF receiver 766 are sized appropriately to ensure that the RF sample time period T.sub.SMPL-RF coincides with at least one packet of a predetermined number of consecutive packets of a data transmission event. As a result, the RF sleep time period T.sub.SLP-RF of the RF receiver 766 can be much longer than the packet time period T.sub.PACKET. In addition, the RF sample time period T.sub.SMPL-RF can be significantly shorter than the packet time period T.sub.PACKET. Accordingly, the RF receiver 766 is operable to sleep for longer periods of time than prior art RF receivers, thus extending the lifetime of the batteries 738B of the motor drive unit 720. For example, the RF sample time period T.sub.SMPL-RF and the RF sleep time period T.sub.SLP-RF may be sized to be approximately 0.1 msec and 17.8 msec, respectively, to ensure that the RF sample time period T.sub.SMPL-RF coincides with at least one packet of five consecutive packets of a data transmission event.
[0145] Four packets 800, 802, 804, and 806 of a data transmission event are shown in
[0146] At time t.sub.2, the third packet 804 is transmitted and is detected by the RF receiver 766, such that the RF receiver wakes up the controller 752. Since the controller 752 wakes up in the middle of the transmission of the third packet 804 (i.e., has missed the beginning of the transmission of the third packet), the controller is unable to properly process the data contained within the third packet. However, the controller 752 is operable to process the third packet 804 sufficiently to determine that a fourth packet 806 will be transmitted after the packet break time t.sub.PKT.sub._.sub.BRK. Accordingly, the controller 752 and the RF receiver 766 are operable to enter the sleep mode for a snooze time period T.sub.SNOOZE, which may be approximately equal to or slightly less than the packet break time period T.sub.PKT.sub._.sub.BRK. As shown in
[0147] When the snooze time period T.sub.SNOOZE expires, the RF receiver 766 and the controller 752 wake up, and the RF receiver begins to listen to RF signals 706 for at least the RF sample time period T.sub.SMPL-RF. Because the RF receiver 766 and the controller 752 are awake at time t.sub.3 when the remote control 718 begins to transmit the fourth packet 806, the receiver is able to receive the entire packet. The receiver 766 remains on for an RF on time period T.sub.ON-RF and is operable to receive the entire packet 806 during an RF receiving event 812, such that the controller 752 is able to properly process the packet 806 of data. Thus, because the RF receiver 766 and the controller 752 go back to sleep during the snooze time period T.sub.SNOOZE (and do not stay awake and fully powered while waiting for the next packet to be transmitted), the life of the batteries 738B is further conserved.
[0148]
[0149] If the SNOOZE flag is set at step 912 (i.e., the RF receiver 766 has been put to sleep for the snooze time period T.sub.SNOOZE), the controller 752 first clears the SNOOZE flag at step 922 and then gets ready to receive a digital message. If the RF receiver 766 is not receiving the start of a digital message at step 924, the controller 752 puts the RF receiver to sleep for the RF sleep time period T.sub.SLP-RF at step 926 and goes back to sleep at step 916, before the RF signal receiving procedure 900 exits. However, if the RF receiver 766 is receiving the start of a digital message at step 924, the controller 752 stores the received message in a receive (RX) buffer at step 928 and puts the RF receiver to sleep for the RF sleep time period T.sub.SLP-RF at step 930. The RF signal receiving procedure 900 exits without the controller 752 being put back to sleep. The controller 752 will go back to sleep after processing the received digital message.
[0150]
[0151] As in the second embodiment, each motorized window treatment 1010 is operable to enable the RF transceiver at a sampling period T.sub.SAMPLE (e.g., approximately 17.8 msec) to detect if an RF signal 1002 is presently being transmitted. Each motorized window treatment 1010 is operable put the RF transceiver to sleep for an RF sleep time period T.sub.SLP-RF that is much longer than the packet time period T.sub.PACKET (e.g., approximately 17.3 msec) and to enable an RF transceiver for the RF sample time period T.sub.SMPL-RF that is much shorter than the packet time period T.sub.PACKET (e.g., approximately 5 msec) so as to conserve battery power. The motorized window treatments 1010 execute an RF signal receiving procedure similar to the RF signal receiving procedure 900 of the second embodiment as shown in
[0152] As shown in
[0153] The load control system 1000 further comprises a wall-mounted button keypad 1040 and a battery-powered tabletop button keypad 1042. The wall-mounted button keypad 1040 is powered from the AC power source 1004 via the line voltage wiring 1005, and the tabletop button keypad 1042 is a battery-powered device. Both of the keypads 1040, 1042 transmit digital messages to the dimmer switch 1030 via the RF signals 1002 in order to provide for remote control of the lighting load 1032. In addition, each of the keypads 1040, 1042 is operable to receive digital status messages via the RF signals 1002 from the dimmer switch 1030 in order to display the status (i.e., on/off state and/or intensity level) of the lighting load 1032. The load control system 1000 further comprises a battery-powered remote control 1044 which is operable to transmit digital messages to the dimmer switch 1030 via the RF signals 1002 in order to provide for remote control of the lighting load 1032. The wall-mounted button keypad 1040, the tabletop button keypad 1042, and the remote control 1044 are also operable to adjust the present position P.sub.PRES of the battery-powered motorized window treatments 1010 by transmitting digital messages via the RF signals 1002. In addition, the battery-powered motorized window treatments 1010 may be operable to transmit status information to the wall-mounted keypad 1040 and tabletop button keypad 1042.
[0154] The load control system 1000 further comprises a battery-powered wireless occupancy sensor 1046 for detecting an occupancy condition (i.e., the presence of an occupant) or a vacancy condition (i.e., the absence of an occupant) in the space in which the occupancy sensor is mounted. The occupancy sensor 1046 is operable to wirelessly transmit digital messages via the RF signals 1002 to the dimmer switch 1030 in response to detecting the occupancy condition or the vacancy condition in the space. For example, in response to detecting an occupancy condition in the space, the occupancy sensor 1046 may transmit a digital message to the dimmer switch 1030 to cause the dimmer switch to turn on the lighting load 1032, and in response to detecting a vacancy condition in the space, transmit a digital message to the dimmer switch to cause the dimmer switch to turn off the lighting load. Alternatively, the occupancy sensor 1046 could be implemented as a vacancy sensor, such that the dimmer switch 1030 would only operate to turn off the lighting load 1032 in response to receiving the vacant commands from the vacancy sensor. Examples of RF load control systems having occupancy and vacancy sensors are described in greater detail in commonly-assigned U.S. Pat. No. 7,940,167, issued May 10, 2011, entitled BATTERY-POWERED OCCUPANCY SENSOR; U.S. Pat. No. 8,009,042, issued Aug. 30, 2011, entitled RADIO-FREQUENCY LIGHTING CONTROL SYSTEM WITH OCCUPANCY SENSING; and U.S. patent application Ser. No. 12/371,027, filed Feb. 13, 2009, entitled METHOD AND APPARATUS FOR CONFIGURING A WIRELESS SENSOR; the entire disclosures of which are hereby incorporated by reference.
[0155] The load control system 1000 further comprises a battery-powered daylight sensor 1048 for measuring an ambient light intensity in the space in which the daylight sensor in mounted. The daylight sensor 1048 wirelessly transmits digital messages via the RF signals 1002 to the dimmer switch 1030. For example, the daylight sensor 1048 may transmit a digital message to the dimmer switch 1030 to cause the dimmer switches to increase the intensities of the lighting load 1032 if the ambient light intensity detected by the daylight sensor 1048 is less than a setpoint light intensity, and to decrease the intensities of the lighting load if the ambient light intensity is greater than the setpoint light intensity. The packet break time period T.sub.PKT.sub._.sub.BRK of the packets transmitted by the daylight sensor 648 may be variable, for example, as a function of the measured light intensity. The battery-powered motorized window treatments 1010 may be operable to receive digital messages from the occupancy sensor 1046 and the daylight sensor 1048 via the RF signals 1002 and to adjust the present position of the window treatments. Examples of RF load control systems having daylight sensors are described in greater detail in commonly-assigned U.S. patent application Ser. No. 12/727,956, filed Mar. 19, 2010, entitled WIRELESS BATTERY-POWERED DAYLIGHT SENSOR, and U.S. patent application Ser. No. 12/727,923, filed Mar. 19, 2010, entitled METHOD OF CALIBRATING A DAYLIGHT SENSOR, the entire disclosures of which are hereby incorporated by reference.
[0156] The load control system 1000 further comprises a battery-powered temperature control device 1050 (e.g., a thermostat) that is operable to control a heating and/or cooling system, e.g., a heating, ventilation, and air conditioning (HVAC) system 1052. The temperature control device 1050 may be coupled to the HVAC system 1052 via an HVAC communication link 1054, e.g., a digital communication link (such as an RS-485 link, an Ethernet link, or a BACnet® link), or alternatively via a wireless communication link (such as an RF communication link). The temperature control device 1050 may comprise an internal temperature sensor for determining a present temperature in the space in which the temperature control device is located. The temperature control device 1050 transmits appropriate digital messages to the HVAC system 1052 to control the present temperature in the building towards a setpoint temperature. Alternatively, the HVAC communication link 1054 could comprise a more traditional analog control link for simply turning the HVAC system 1052 on and off. The temperature control device 1050 comprises a user interface, e.g., a touch screen 1056, for displaying the present temperature and the setpoint temperature, and for receiving user inputs for adjusting the setpoint temperature. The temperature control device 1050 is operable to receive RF signals 1002 from a wireless temperature sensor 1056 for determining the present temperature in the space, for example, at a location away from the temperature control device 1050. In addition, the motor drive units 1020 of each of the motorized window treatments 1010 may be operable to transmit the temperature measurements from the internal and/or external temperature sensors 160, 162 to the temperature control device 1050.
[0157] Each of the battery-powered devices of the load control system 1000 (i.e., the tabletop button keypad 1042, the remote control 1044, the occupancy sensor 1046, the daylight sensor 1048, and the temperature control device 1050) is operable to enable their respective RF transceivers at a sampling period T.sub.SAMPLE (e.g., approximately 17.8 msec) to detect if an RF signal 1002 is presently being transmitted as described above for the motorized window treatments 1010. Each of these battery-powered devices is operable put its RF transceiver to sleep for an RF sleep time period T.sub.SLP-RF that is much longer than the packet time period T.sub.PACKET (e.g., approximately 5 msec) and to enable the RF transceiver for the RF sample time period T.sub.SMPL-RF that is much shorter than the packet time period T.sub.PACKET (e.g., approximately 17.3 msec) so as to conserve battery power.
[0158] The load control system 1000 further comprises signal repeaters 1060A, 1060B, which are operable to retransmit any received digital messages to ensure that all of the control devices of the load control system receive all of the RF signals 1002. The load control system 1000 may comprise, for example, one to five signal repeaters depending upon the physical size of the system. Each of the control devices, (e.g., the motorized window treatments 1010, the dimmer switch 1030, the tabletop button keypad 1042, the wall-mounted button keypad 1040, the occupancy sensor 1046, the daylight sensor 1048, and the temperature control device 1050) of the load control system 1000 are located within the communication range of at least one of the signal repeaters 1060A, 1060B. The signal repeaters 1060A, 1060B are powered by the AC power source 1004 via power supplies 1062 plugged into electrical outlets 1064.
[0159] According to the third embodiment of the present invention, one of the signal repeaters (e.g., signal repeater 1060A) operates as a “main” repeater (i.e., a main controller) to facilitate the operation of the load control system 1000. The main repeater 1060A has a database, which defines the operation of the load control system, stored in memory. For example, the main repeater 1060A is operable to determine which of the lighting load 1032 is energized and to use the database to control any visual indicators of the dimmer switch 1030 and the keypads 1042, 1040 accordingly to provide the appropriate feedback to the user of the load control system 1000. In addition, the control devices of the load control system may be operable to transmit status information to the signal repeaters 1060A, 1060B. For example, the motor drive unit 1020 of each of the motorized window treatments 1010 may be operable to transmit a digital message representative of the magnitude of the respective battery voltage to the signal repeaters 1060A, 1060B, a digital message including a low-battery indication to the signal repeaters when operating in the low-battery mode, or a digital message including a representation of the present position P.sub.PRES of the motorized window treatment.
[0160] As mentioned above, the load control system 1000 may comprise one to five signal repeaters depending upon the physical size of the system. The control devices of the load control system 1000 are each operable to adjust the RF sampling period T.sub.SAMPLE in response to the total number N.sub.RPTR of signal repeaters within the load control system 1000. Specifically, each control device is operable to adjust the RF sleep time period T.sub.SLP-RF, while keeping the RF sampling time period T.sub.SMPL-RF constant. The control devices adjust the respective sampling periods because packets of data may be transmitted differently via the RF signals 1002 depending on the number of repeaters in the load control system 1000. In particular, the packet break time period T.sub.PKT.sub._.sub.BRK of the data transmissions may vary in response to the number of repeaters to ensure that the signal repeaters in the load control system 1000 have sufficient time to propagate a given packet. Because the packet break time period T.sub.PKT.sub._.sub.BRK is a factor in appropriately sizing the RF sleep time period T.sub.RF-SLEEP of each of the control devices to ensure that an RF sampling event coincides with a packet transmission as discussed above with respect to
[0161]
[0162] If the motor drive unit 1020 has received a packet containing the number of repeaters N.sub.RPTR, the motor drive unit determines whether the number of repeaters N.sub.RPTR is greater than three at step 1114. If the number of repeaters N.sub.RPTR is not greater than three at step 1114, the motor drive unit 1020 uses the first RF sleep time period value T.sub.SLP-RF1 (i.e., approximately 17.8 msec) as the RF sleep time period T.sub.SLP-RF at step 1112 before the sampling rate selection procedure 1100 exits. If the number of repeaters N.sub.RPTR is greater than three at step 1114, the motor drive unit 1020 uses a second RF sleep time period value T.sub.SLP-RF2 (e.g., approximately 16.3 msec) as the RF sleep time period T.sub.SLP-RF at step 1116 before the RF sampling rate selection procedure 1100 exits. The RF sampling rate selection procedure 1100 ensures that the motor drive unit 1020 adjusts its RF sampling rate T.sub.SAMPLE in response to the number of repeaters in the load control system 1000 to optimize reliability, response time, and battery life. The other battery-powered devices of the load control system 1000 (i.e., the tabletop button keypad 1042, the remote control 1044, the occupancy sensor 1046, the daylight sensor 1048, and the temperature control device 1050) may also execute the RF sampling rate selection procedure 1100.
[0163] The RF transceivers of the control devices of the load control system 1000 are characterized by a signal strength threshold which is used to detect the transmitted RF signals 1002. Particularly, the RF transceiver of each of the control devices of the load control system 1000 is characterized by an adjustable signal strength threshold.
[0164] During a configuration or set-up procedure of each of the motor drive units 1020, a user may be operable to select the signal strength of the RF transceiver as having either the first threshold 1160 or the second threshold 1170. When using the second threshold 1170 to detect RF signals 1002, the RF transceiver is operable to detect RF signals of a lower signal strength which can improve the range performance of the RF transceiver (i.e., the RF transceiver can detect RF signals sent from control devices that are located farther away). However, the second threshold 1170 may cause the RF transceiver to be more sensitive to noise events as the noise floor 1080 may occasionally exceed the second threshold. Each time the RF transceiver receives any RF energy (RF signals 1002, RF noise, etc.) that exceeds the second threshold 1170 during the RF sampling time period T.sub.SMPL-RF, the RF transceiver wakes up the controller of the motor drive unit 1020, such that the controller then consumes additional power which ultimately reduces the life of the batteries of the motor drive unit. When the RF transceiver uses the first threshold 1160 to detect RF signals 1002, the RF transceiver is less likely to detect RF signals having a lower signal strength, but is less susceptible to noise events. Because the RF transceiver only responds to RF energy (RF signals 1002, RF noise, etc) that exceeds the first threshold 1160, the RF transceiver does not wake up the controller as frequently as when the second threshold 1170 is used. As a result, the life of the batteries can be further extended when the RF transceiver uses the first threshold 1160.
[0165] The first and second thresholds 1160, 1170 may be predetermined values. For example, the first threshold 1160 may have a value of approximately −90 dBm and the second threshold 1170 may have a value of approximately −97 dBm. Alternatively, the value of the adjustable threshold of the RF transceiver could be determined automatically during the configuration procedure of the motor drive unit 1020. For example, the RF transceiver may be operable to detect an average magnitude of the noise floor 1180 and may also be able to detect a magnitude of the signal strength 1150 of the nearest signal repeater 1060A, 1060B, and then provide these magnitudes to the controller of the motor drive unit. The controller may then calculate an optimal value of a threshold for the RF transceiver that will preserve battery life and provide appropriate range performance. For example, the controller may halve the sum of the magnitude of the noise floor 1180 and the magnitude of the signal strength 1150 of the nearest signal repeater to calculate the value of the threshold for the RF transceiver. In addition, in the event that the calculated threshold value of the RF transceiver is too close (e.g., within ˜5 dBm) to the noise floor 1180, the load control system 1000 may be operable to prompt a user, e.g., through a programming interface (not shown), to add another signal repeater to the system. By adding another signal repeater to the system, the magnitude of the signal strength of the nearest signal repeater may increase, thus increasing the calculated threshold of the RF transceiver. As a result, the battery life of each of the motor drive units 1020 may be further extended.
[0166] During the configuration process of the load control system 1000, the motor drive units 1020 are each assigned to a particular frequency channel such that each motor drive can receive RF signals 1002 transmitted on that frequency channel. During normal operation, the motor drive units 1020 will each detect any packet of information that is transmitted on the respective assigned frequency channel—even if that packet does not contain data that is addressed to the motor drive unit. As soon as the RF transceiver of each motor drive unit 1020 begins to detect a packet transmitted on the assigned frequency channel, the RF transceiver will wake up the controller of the motor drive unit as previously described. The controller will then process the packet to determine whether it must adjust the present position P.sub.PRES of the motorized window treatment 1010. In the event that the packet is not addressed to the motor drive unit 1020 (e.g., the packet contains information only for a dimmer switch 1030), the controller will take no further action and will go back to sleep. However, because the controller woke up to process the packet, the controller consumed power unnecessarily, and negatively impacted the life of the batteries of the motor drive unit 1020.
[0167] Because the load control system 1000 comprises many devices that are operable to send and/or receive RF signals 1002, there can be a very large number of packets regularly transmitted within the system. Many of these packets may not be addressed to the motor drive units 1020, and as a result, need not be processed by the controller of each of the motor drive units. According to an aspect of the present invention, the battery-power motorized window treatments 1010 may be configured to only listen to RF signals 1002 transmitted on an alternate channel distinct from the channels used by the other devices of the load control system 1000.
[0168]
[0169]
[0170]
[0171] In the event that the first signal repeater 1460A receives an packet that is transmitted on channel A and is addressed to at least one of the battery-powered motorized window treatments 1010, the signal repeater 1460A transmits a digital message (e.g., including the data from the packet) to the second signal repeater 1460B via the digital communication link 1466. Upon receiving the information via the digital communication link 1460B, the second signal repeater 1460B transmits the packets to the battery-powered motorized window treatments 1010 via the RF signals 1002 using the alternate frequency B. The packets transmitted to the motorized window treatments 1010 by the second signal repeater 1460B include the same (or similar) data as the packets that were received by the first signal repeater 1460A. Thus, the battery-powered motorized window treatments 1010 only listen to RF signals 1002 transmitted on the alternate frequency channel B distinct from the channel used by the other devices of the load control system 1000 in order to further preserve the battery life of the battery-powered window treatments.
[0172] Examples of battery-powered remote controls and RF control systems are described in greater detail in commonly-assigned U.S. patent application Ser. No. 12/399,126, filed Mar. 6, 2009, entitled WIRELESS BATTERY-POWERED REMOTE CONTROL HAVING MULTIPLE MOUNTING MEANS; U.S. Pat. No. 7,573,208, issued Aug. 22, 2009, entitled METHOD OF PROGRAMMING A LIGHTING PRESET FROM A RADIO-FREQUENCY REMOTE CONTROL, and U.S. patent application Ser. No. 12/033,223, filed Feb. 19, 2008, entitled COMMUNICATION PROTOCOL FOR A RADIO-FREQUENCY LOAD CONTROL SYSTEM, the entire disclosures of which are hereby incorporated by reference.
[0173]
[0174]
[0175] Each mounting bracket 1670 of the motorized window treatment 1610 comprises a release button 1672, which may be actuated (e.g., pushed) to release the headrail 114 from the locked position, such that the headrail may be rotated into the service position and the batteries 138 may be accessed as shown in
[0176]
[0177] As shown in
[0178] Each mounting bracket 1670 further comprises a spring 1684 (
[0179] Each mounting bracket 1670 further comprises a latch mechanism 1686 (
[0180] While the present invention has been described with reference to the battery-powered motorized window treatments having the cellular shade fabric 112, the concepts of the present invention could be applied to other types of motorized window treatments, such as, for example, roller shades, draperies, Roman shades, Venetian blinds, and tensioned roller shade systems. An example of a roller shade system is described in greater detail in commonly-assigned U.S. Pat. No. 6,983,783, issued Jan. 10, 2006, entitled MOTORIZED SHADE CONTROL SYSTEM, the entire disclosure of which is hereby incorporated by reference. An example of a drapery system is described in greater detail in commonly-assigned U.S. Pat. No. 6,994,145, issued Feb. 7, 2006, entitled MOTORIZED DRAPERY PULL SYSTEM, the entire disclosure of which is hereby incorporated by reference. An example of a Roman shade system is described in greater detail in commonly-assigned U.S. patent application Ser. No. 12/784,096, filed Mar. 20, 2010, entitled ROMAN SHADE SYSTEM, the entire disclosure of which is hereby incorporated by reference. An example of a Venetian blind system is described in greater detail in commonly-assigned U.S. patent application Ser. No. 13/233,828, filed Sep. 15, 2011, entitled MOTORIZED VENETIAN BLIND SYSTEM, the entire disclosure of which is hereby incorporated by reference. An example of a tensioned roller shade system is described in greater detail in commonly-assigned U.S. Pat. No. 8,056,601, issued Nov. 15, 2011, entitled SELF-CONTAINED TENSIONED ROLLER SHADE SYSTEM, the entire disclosure of which is hereby incorporated by reference.
[0181] Additional procedures for controlling motorized window treatments are described in greater detail in commonly-assigned, co-pending U.S. patent application Ser. No. 12/563,786, filed Aug. 11, 2009, entitled METHOD OF AUTOMATICALLY CONTROLLING A MOTORIZED WINDOW TREATMENT WHILE MINIMIZING OCCUPANT DISTRACTIONS, and U.S. patent application Ser. No. 12/845,016, filed Jul. 28, 2010, entitled LOAD CONTROL SYSTEM HAVING AN ENERGY SAVINGS MODE, the entire disclosures of which are hereby incorporated by reference.
[0182] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.