Vehicle control device and method of controlling the same

Abstract

While an engine (drive source) is being driven, when a long pressing operation (selection operation on a predetermined shift range) on an N-range button via a SBW shifter is executed, an engine drive/stop button blinks to notify a driver (step S1 and step S2). During the blinking of the engine drive/stop button, when the engine drive/stop button is pressed and the engine (drive source) is stopped, a neutral range is maintained without being switched to a parking range automatically (step 3 and step 4).

Claims

1. A vehicle control device comprising: a control unit that switches a shift range of an automatic transmission by an actuator based on a vehicle speed detected by a vehicle speed sensor and an operation result of a shift range selector by a driver, wherein the control unit switches the shift range to a parking range by the actuator automatically when a vehicle power source is turned off or a drive source is stopped in a state that the vehicle speed detected by the vehicle speed sensor is equal to or less than a predetermined speed and, the control unit notifies the driver via a warning device when a predetermined shift range selection operation is executed by the shift range selector in a state that the vehicle power source is on or the drive source is being driven; and the control unit maintains a neutral range when an operation in which the vehicle power source is turned off or the drive source is stopped is executed while the warning device notifies.

2. The vehicle control device according to claim 1, wherein the predetermined shift range selection operation is an operation in which a selection operation for the neutral range by the shift range selector continues for a time period equal to or more than a first predetermined period.

3. The vehicle control device according to claim 2, wherein the control unit notifies the driver for a second predetermined period via the warning device, stops a notification when the notification by the warning device exceeds the second predetermined period, and switches the shift range to the parking range by the actuator automatically when the operation in which the vehicle power source is turned off or the drive source is stopped is executed after the notification stops.

4. The vehicle control device according to claim 1, wherein the control unit notifies the driver for a predetermined period via the warning device, stops a notification when the notification by the warning device exceeds the predetermined period, and switches the shift range to the parking range by the actuator automatically when the operation in which the vehicle power source is turned off or the drive source is stopped is executed after the notification stops.

5. The vehicle control device according to claim 4, further comprising: a starter switch that operates to start/stop the drive source, wherein the warning device blinks an LED provided with the starter switch for the predetermined period.

6. The vehicle control device according to claim 1, wherein the control unit sets the vehicle power source partially in a start-up state for a predetermined period and notifies the driver of a state where the neutral range is maintained when the neutral range is maintained in the state that the vehicle power source is turned off or the drive source is stopped.

7. The vehicle control device according to claim 1, wherein the control unit sets a predetermined power source necessary for an operation of the shift range selector in a start-up state when the neutral range is maintained in the state that the vehicle power source is turned off or the drive source is stopped, and switches the automatic transmission to the parking range when an operation to select the parking range by the shift range selector is executed.

8. The vehicle control device according to claim 1, wherein the vehicle has a slope detector that detects a road slope, and the control unit switches to the parking range without maintaining the neutral range even if an operation to maintain the neutral range is executed in the state that the vehicle power source is turned off or the drive source is stopped when the road slope detected by the slope detector is equal to or more than a predetermined slope.

9. The vehicle control device according to claim 8, wherein the control unit switches to the parking range automatically when the vehicle speed detected by the vehicle speed sensor is equal to or more than the predetermined speed while the neutral range is maintained in the state that the vehicle power source is turned off or the drive source is stopped.

10. A method of controlling a vehicle control device having a control unit that switches a shift range of an automatic transmission by an actuator based on a vehicle speed detected by a vehicle speed sensor and an operation result of a shift range selector by a driver, the method executed by the control unit comprising: switching the shift range to a parking range by the actuator automatically when a vehicle power source is turned off or a drive source is stopped in a state that the vehicle speed detected by the vehicle speed sensor is equal to or less than a predetermined speed, notifying the driver via a warning device when a predetermined shift range selection operation is executed by the shift range selector in a state that the vehicle power source is on or the drive source is being driven; and maintaining a neutral range when an operation in which the vehicle power source is turned off or the drive source is stopped is executed while the warning device notifies.

11. The method of controlling the vehicle control device according to claim 10, wherein the predetermined shift range selection operation is an operation in which a selection operation for the neutral range by the shift range selector continues for a time period equal to or more than a first predetermined period.

12. The method of controlling the vehicle control device according to claim 11, wherein the method further comprises: notifying the driver for a second predetermined period via the warning device; stopping the notification when the notification by the warning device exceeds the second predetermined period; and switching the shift range to the parking range by the actuator automatically when the operation in which the vehicle power source is turned off or the drive source is stopped is executed after the notification stops.

13. The method of controlling the vehicle control device according to claim 10, wherein the method comprises: notifying the driver for a predetermined period via the warning device; stopping a notification when the notification by the warning device passes the predetermined period; and switching the shift range to the parking range by the actuator automatically when the operation in which the vehicle power source is turned off or the drive source is stopped is executed after the notification stops.

14. The method of controlling the vehicle control device according to claim 13, vehicle control device further comprising: a starter switch that operates to start/stop the drive source, wherein the method comprising: blinking an LED provided with the starter switch for the predetermined period by the warning device.

15. The method of controlling the vehicle control device according to claim 10, wherein the method further comprises: setting the vehicle power source partially in a start-up state for a predetermined period; and notifying the driver of a state where the neutral range is maintained when the neutral range is maintained in the state that the vehicle power source is turned off or the drive source is stopped.

16. The method of controlling the vehicle control device according to claim 10, wherein the method further comprises: setting a predetermined power source necessary for an operation of the shift range selector in a start-up state when the neutral range is maintained in a state that the vehicle power source is turned off or the drive source is stopped; and switching the automatic transmission to the parking range when an operation to select the parking range by the shift range selector is executed.

17. The method of controlling the vehicle control device according to claim 10, wherein the vehicle has a slope detector that detects a road slope, and the method further comprises: switching to the parking range without maintaining the neutral range even if an operation to maintain the neutral range is executed in the state that the vehicle power source is turned off or the drive source is stopped when the road slope detected by the slope detector is equal to or more than a predetermined slope.

18. The method of controlling the vehicle control device according to claim 17, wherein the method further comprises: switching to the parking range automatically when the vehicle speed detected by the vehicle speed sensor is equal to or more than the predetermined speed while the neutral range is maintained in the state that the vehicle power source is turned off or the drive source is stopped.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a block diagram illustrating a structure of a vehicle control device according to an embodiment of the invention; and

(2) FIG. 2 is a control flowchart which the vehicle control device illustrated in FIG. 1 executes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(3) An embodiment of the invention according to the invention will be described below in detail, referring to the accompanying drawings. FIG. 1 is a block diagram illustrating a structure of a vehicle control device according to an embodiment of the invention. FIG. 2 is a control flowchart which the vehicle control device illustrated in FIG. 1 executes.

(4) As illustrated in FIG. 1, a vehicle has an SBW shifter (shift range selection unit or shift range selector) 12 of a shift by wire (SBW) type, a shifter ECU (control unit) 14, an automatic transmission 16, a transmission control unit (TCU) (control unit) 18, an engine ECU (control unit) 20, a power source ECU (power switch, control unit) 22, an engine drive/stop button (starter switch) 24, a vehicle speed sensor (vehicle speed detection unit) 26, a gyro sensor (road slope detection unit) 28, a notification unit (or device which provides visible and/or audible warnings to a driver) 30, and the like. The SBW shifter 12 electrically detects a shift range operation by a driver and switches a shift range by electric signals. The shifter ECU 14 controls the SBW shifter 12. The TCU 18 controls the automatic transmission 16 to switch the sift range. The vehicle speed sensor 26 detects a vehicle speed. The gyro sensor 28 detects a road slope. The notification unit 30 notifies the driver. The shifter ECU 14, the TCU 18, the engine ECU 20 and the power source ECU 22 are included in a vehicle control device 10.

(5) The SBW shifter 12 may be either a button type which switches the shift range by pressing buttons or a lever type which switches the shift range by an operation of the driver with a shift lever. In the embodiment, the button type is conveniently used for explanations.

(6) The SBW shifter 12 includes a P-range button which selects a parking range (P-range), an R-range button which selects a reverse range (R-range), an N-range button which selects a neutral range (N-range), a D-range button which selects a drive range (D-range), and the like.

(7) The automatic transmission 16 has an actuator (not illustrated) which switches variable speed levels based on control of the TCU 18.

(8) The shifter ECU 14, the TCU 18, the engine ECU 20 and the power source ECU 22 are constituted as known microcomputers having a CPU, a ROM, a RAM and the like, respectively. The CPU executes a control flowchart described later based on programs stored in the ROM or programs loaded in the RAM.

(9) In a normal period, the engine drive/stop button 24 turns off in an off-state and turns on in an on-state after being pressed. Further, in the on-state, the engine drive/stop button 24 sends engine drive signals to the power source ECU 22 and the engine ECU 20, and thereby an engine is driven. Still further, in the off-state, the engine drive/stop button 24 sends engine stop signals to the power source ECU 22 and the engine ECU 20, and thereby the driven engine is stopped. When the engine drive/stop button 24 is pressed and the drive of the engine stops, the engine drive/stop button 24 sends the engine stop signals to the power source ECU 22. The power source ECU 22 turns off an entire vehicle power source based on the engine stop signals.

(10) Yet further, the engine drive/stop button 24 itself may also function as the notification unit 30. It is possible to notify the driver by blinking an LED (not illustrated) provided in a casing of the engine drive/stop button 24. The engine ECU 20 can start or stop the blinking of the engine drive/stop button 24 by sending signals to the power source ECU 22.

(11) The engine ECU 20 controls the drive/stop of the engine based on the engine drive signals and the engine stop signals from the engine drive/stop button 24.

(12) The power source ECU 22 controls the vehicle power source to turn on/off based on the engine drive signals and the engine stop signals sent from the engine drive/stop button 24 to the power source ECU 22.

(13) The gyro sensor 28 detects the road slope based on a tilt angle in a longitudinal direction. A yaw rate sensor, a G sensor or the like may be employed as a road slope detection unit in place of the gyro sensor 28.

(14) The notification unit 30 notifies (makes the drive recognize) by sounds or indications to the driver. For example, the vehicle control device 10 may notify to the driver by sounds such as bleeps from a speaker as the notification unit 30 mounted in the vehicle or may notify by characters, signs or the like displayed on a display section as the notification unit 30 in an instrument panel. Further, the vehicle control device 10 may notify by the characters, the signs or the like displayed on a display section as the notification unit 30 in a navigation system. The notification unit 30 may use both the sounds and the indications.

(15) The vehicle control device 10 according to the embodiment is basically constituted as described above. Operations and effects thereof will be explained below.

(16) A control in the normal period will be explained.

(17) When the vehicle speed detected by the vehicle speed sensor 28 is equal to or less than a predetermined speed and the driver presses the engine drive/stop button 24 to make a stop state of the engine, the engine ECU 20 drives the actuator (not illustrated) of the automatic transmission 16 via the TCU 18. The shift range is switched to the parking range (P-range) automatically by the actuator.

(18) FIG. 2 is a control flowchart which the vehicle control device 10 according to the embodiment executes. When the vehicle speed detected by the vehicle speed sensor 28 is equal to or less than the predetermined speed and the vehicle is in a driving state of the engine where the engine drive/stop button 24 is not pressed by the driver, the shifter ECU 14 determines whether the N-range button of the SBW shifter 12 is pressed long for two second (or more) by the driver (step S1).

(19) The long pressing operation on the N-range button by the driver functions as a predetermined shift selection operation by the SBW shifter 12. Further, the two seconds when the N-range button is pressed long functions as a first predetermined period, but the period is not limited to two seconds and may be a time frame during which the N-range button is continuously pressed more than a predetermined time.

(20) When the shifter ECU 14 determines that the N-range button is pressed long for two seconds (Yes in step S1), the engine ECU 20 makes the engine drive/stop button 24 blink via the power source ECU 22 (step S2). In other words, the engine drive/stop button 24 starts to blink to notify the driver with the long pressing operation on the N-range button by the driver as a trigger.

(21) During the blinking of the engine drive/stop button 24, the engine ECU 20 determines whether the engine drive/stop button 24 is pressed via the power source ECU 22 (step S3). When the engine ECU 20 determines that the engine drive/stop button 24 is pressed by the driver to be in the off-state during the blinking of the engine drive/stop button 24 (Yes in step S3), the engine ECU 20 releases that the shift range is switched to the P-range automatically via the TCU 18 and switches a transmission gear of the automatic transmission 16 to the N-range (to change gears) (step S4). Further, the engine ECU 20 makes the engine in the stopped state (step S5) and the control flowchart terminates.

(22) On the other hand, when the engine ECU 20 determines that the engine drive/stop button 24 is not being pressed during the blinking of the engine drive/stop button 24 (No in step S3), the engine ECU 20 activates a timer (not illustrated) and determines whether three seconds pass since the engine drive/stop button 24 starts to blink (step S6). The three seconds pass functions as a passage of a second predetermined period.

(23) When the engine drive/stop button 24 is being in the on-state without being pressed by the driver since the engine drive/stop button 24 starts to blink, and the engine ECU 20 determines that three seconds pass since the blinking starts (Yes in step S6), the blinking of the engine drive/stop button 24 stops (step S7), and then the process returns to step S1. Since notification period (blinking of the engine drive/stop button 24) to the driver passes over the second predetermined period, the notification is stopped.

(24) On the other hand, when the engine drive/stop button 24 is not pressed by the driver since the engine drive/stop button 24 starts to blink and the engine ECU 20 determines that three seconds do not pass since the blinking starts (No in step S6), the process returns to step S2.

(25) In step S1, when the sifter ECU 14 determines that the N-range button is not pressed long for two seconds (No in step S1), the engine ECU 20 further determines whether the engine drive/stop button 24 is pressed (step S8).

(26) When the engine drive/stop button 24 is pressed by the driver (Yes in step S8), the engine ECU 20 switches the transmission gear of the automatic transmission 16 to the P-range (step S9) via the TCU 18 and makes the engine in the stopped stops (step S5). Then, the control flowchart terminates. On the other hand, when the engine drive/stop button 24 is not pressed by the driver (No in step S8), the process returns to step S1.

(27) In the embodiment, when the long pressing operation (selection operation for a predetermined shift range) on the N-range button via the SBW shifter 12 is executed in the state that the engine (drive source) is being driven, the engine drive/stop button 24 blinks to notify the driver (see steps S1 and S2). When the engine drive/stop button 24 is pressed to be in the off-state for stopping the engine (drive source) during the blinking of the engine drive/stop button 24, the neutral range can be maintained without being switched to the parking range automatically (see steps S3 and S4). As a result, in the embodiment, the operations can be simplified compared with the related art in which both the neutral range and the ignition switch are operated simultaneously.

(28) In case that an ignition switch (IG-S) is provided in the vehicle, the phase of the vehicle power source is turned off means that the ignition switch in the on-state is switched to an ACC state or the off-state in this case. Further, the phrase of the drive source stops means that the ignition switch in the on-state is switched to the ACC state, the off-state or an idle reduction state (ACC state) in this case.

(29) Further, in the embodiment, when the engine (drive source) is stopped during the notification to the driver, the neutral range is maintained with the simple operations (steps S2 to S4). Therefore, even if the driver presses long on the N-range button by mistake (unintentionally), the driver can be made aware by the blinking of the engine drive/stop button 24 as the notification unit 30. Therefore, the release of the automatic switching to the parking range due to operation errors can be prevented.

(30) Further, in the embodiment, when the N-range button is pressed long for two seconds, the driver is notified by starting the blinking of the engine drive/stop button 24. Therefore, in the normal shift switching operation, that the long pressing operation of the N-range button continues for two seconds is lowly probable, and the notification to the driver cannot be executed. Therefore, a notification error to the driver can be avoided.

(31) Still further, in the embodiment, the engine must be stopped by pressing the engine drive/stop button 24 to be in the off-state during the blinking of the engine drive/stop button 24 (steps S2 and S3) to maintain the neutral range at the stop of the engine (drive source). Therefore, the driver needs to execute the predetermined shift range selection operation with driver's intention for operation, and thereby the operation errors by the driver can be avoided.

(32) Still further, in the embodiment, when the engine (drive source) is stopped after the notification to the driver terminates, the neutral range is not maintained and the transmission gear is switched to the parking range automatically (steps S7, S8 and S9). Therefore, the operation errors by the driver can be further avoided.

(33) Still further, in the embodiment, the driver can be easily made aware that an operation to maintain the neutral range will be executed by notifying to blink the engine drive/stop button 24 as a necessary operation member to the driver. Therefore, the operation errors by the driver can be further avoided.

(34) In place of the blinking of the engine drive/stop button 24, indications on a navigation screen or on a display section of a meter panel or the like can be conceived. However, since that the driver does not look at the screen or the display section when operating the engine drive/stop button 24 can be conceived, the blinking of the engine drive/stop button 24 at which the driver necessarily looks when the driver operates is effective measures ergonomically.

(35) A control after the control flowchart illustrated in FIG. 2 terminates will be explained.

(36) When the neutral range is maintained in the state that the engine (drive source) stops, the power source ECU 22 delays the vehicle power source partially by a delay circuit (not illustrated). For example, the blinking of the engine drive/stop button 24 is continued for approximately only ten minutes (third predetermined time).

(37) With the operations described above, after the engine stops, the driver is notified that the neutral range is maintained for approximately only ten minutes. Therefore, the driver can surely recognize that the neutral range is maintained. The notification to the driver after the engine stops is started by drive signals from the engine ECU 20. The notification may be executed via the indications on the display section in the navigation system, blinking of a hazard lamp, sounds from a speaker mounted in the vehicle to the driver, or the like. Further, after the engine stops, the engine ECU 20 sends control signals to the SBW shifter 12 via the shifter ECU 14 to turn on or blink the neutral range button of the SBW shifter 12 for a predetermined time to notify the driver.

(38) Further, when the neutral range is maintained in the state that the engine (drive source) stops, the power source ECU 22 delays a predetermined power source necessary for operating the SBW shifter 12 by the delay circuit (not illustrated). When the driver operates to select the parking range in the SBW shifter 12, the automatic transmission 16 is switched to the parking range.

(39) With the operations described above, when the neutral range is maintained in the state that the engine (drive source) stops, the parking range can be selected by the shift operation of the driver without executing a starting-up operation for the vehicle power source again. Therefore, the operation to switch to the parking range is facilitated.

(40) Still further, when the road slope detected by the gyro sensor 28 is equal to or more than a predetermined slope, even if a predetermined operation in which the neutral range is maintained is executed in the off-state of the vehicle power source or at the stop of the engine (drive source), the engine ECU 20 switches to the parking range without maintaining the neutral range.

(41) With the operation described above, when the road slope is equal to or more than the predetermined slope, the shift range is switched to the parking range without maintaining the neutral range. Therefore, the vehicle is prevented from moving due to the road slope.

(42) Yet further, when the road slope detected by the gyro sensor 28 is equal to or more than the predetermined slope and the vehicle speed detected by the vehicle speed sensor 26 is equal to or more than a predetermined speed, the engine ECU 20 drives the actuator of the automatic transmission 16 via the TCU 18 to switch to the parking range automatically.

(43) With the operations described above, in case that the neutral range is maintained in the state that the engine (drive source) stops, for example, when the vehicle moves due to the road slope and the speed thereof becomes equal to or more than a predetermined speed, the vehicle can be prevented from moving by switching to the parking range automatically.