Method for detecting a pinching situation when moving a movable component

Abstract

A method for detecting a pinching situation when moving an adjustable component for closing an opening by means of an electric motor in a vehicle comprises the following steps: providing a trigger threshold for a closing force exerted by the electric motor on the component or a physical variable on which it is based, with which the electric motor is operated, for at least one movement position of the component within a travel path available to it for the movement; moving the component into the movement position; determining a current value of the closing force or of the physical variable on which it is based for the at least one movement position; comparing the current value and the trigger threshold; and outputting a trigger signal which indicates the pinching situation dependent from the result of the comparison.

Claims

1: A method for detecting a pinching situation when moving an adjustable component for closing an opening by means of an electric motor in a vehicle, comprising the steps: providing a trigger threshold for a closing force exerted by the electric motor on at least one of the component and a physical variable on which the component is based, with which the electric motor is operated, for at least one movement position of the component within of the travel path available to it for the movement; moving the component into the movement position; determining a current value of at least one of the closing force and the physical variable on which the closing force is based for the at least one movement position; comparing the current value and the trigger threshold; outputting a trigger signal which indicates the pinching situation dependent from the result of the comparison; determining a time period over which the component was held in other movement positions up to a point in time of the movement of the component into the movement position, in which the opening was continuously not in a closed state by the adjustable component, and adapting at least one of the provided trigger threshold and the determined current value, wherein the provided trigger threshold is increased, dependent from the determined time period, wherein the determined current value is decreased, dependent from the determined time period relative to the predefined trigger threshold; and using at least one of: the adapted trigger threshold and the adapted current value in the step of comparing the current value and the trigger threshold.

2: The method for detecting a pinching situation according to claim 1, further comprising: reversing the component dependent from the trigger signal.

3: The method for detecting a pinching situation according to claim 1, wherein the determination of the time period comprises: querying a first time stamp at which the component was last moved out of a completely closed position by operating the electric motor; querying a second time stamp at which the component reaches or begins to reach the at least one movement position by operating the electric motor during the current closing; and calculating the time period from the first time stamp and the second time stamp.

4: The method for detecting a pinching situation according to claim 1, wherein carrying out, if a first time period is determined, at least one of: a first adaptation of the trigger threshold and the current value, which leads to a first difference with respect to the originally provided trigger threshold, and carrying out, if a second time period is determined which is greater than or lasts longer than the first time period, at least one of: a second adaptation of the trigger threshold and the current value, which leads to a second difference with respect to the originally provided trigger threshold, wherein the second difference is greater than the first difference.

5: The method for detecting a pinching situation according to claim 1, wherein defining within the travel path available to the component for the movement a predetermined section of the travel path in which the component may come into contact with the at least one seal; and carrying out at least one of: the adaptation of the trigger threshold and the current value depending on whether the at least one movement position of the component lies within the predetermined section of the travel path.

6: The method for detecting a pinching situation according to claim 1, wherein setting different values for the trigger threshold at different movement positions along the travel path.

7: The method for detecting a pinching situation according to claim 1, wherein calculating at least one of: the adaptation of the trigger threshold and the current value using a formula proceeding from at least one of: the provided trigger threshold and from the determined current value and a term to be added with a linear dependence on the determined time period.

8: The method for detecting a pinching situation according to claim 1, wherein the component is at least one of: a sunroof, a sliding roof, a glass roof, and a roller blind system and the corresponding opening is configured in the roof structure of a vehicle.

9: A device for detecting a pinching situation when moving an adjustable component for closing an opening by means of an electric motor in a vehicle, comprising: first module unit, which is configured to operate the electric motor, to detect a pinching situation in the process and to control the electric motor as a function of the detection in order to reverse the component, wherein the first module unit is further configured: to receive a trigger threshold for a closing force exerted by the electric motor on at least one of the component and a physical variable on which the component is based, with which the electric motor is operated, for at least one movement position of the component within a travel path available to it for the movement; to move the component into the movement position by operating the electric motor; to obtain at least one of: a current value of the closing force and the physical variable on which the current value of the closing force it is based for the at least one movement position; to compare the current value and the trigger threshold; and to output a trigger signal which indicates the pinching situation dependent from the result of the comparison and with which, the closing operation of the component is switched to its reversing operation; second module unit, which is configured: to read in at least one of: a trigger threshold and at least one of: a current value of the closing force and the physical variable on which the current value of the closing force is based for the at least one movement position; to determine a time period over which the component was held in other movement positions up to a point in time of the movement of the component into the movement position, in which the opening was continuously not closed by the adjustable component; to adapt, to at least one of: to increase, the read-in, predefined trigger threshold dependent from the determined time period, and to decrease, the read-in, current value dependent from the determined time period relative to the read-in trigger threshold; and to transmit at least one of: the adapted trigger threshold and the adapted current value to the first module unit.

10: The method for detecting a pinching situation according to claim 8, wherein the electric motor is a DC motor, in particular a DC motor or a BLDC motor.

11: The method for detecting a pinching situation according to claim 8, wherein the electric motor is a BLDC motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] There is shown in:

[0062] FIG. 1 an overview of a device for detecting a pinching situation according to an exemplary embodiment of the invention;

[0063] FIG. 2 a cross-sectional view of a detail with an adjustable component (glass roof) resting on three seals in an opening;

[0064] FIG. 3: a comparison of the currently determined closing force (Pact) plotted over the travel path (R.sub.tot) of the component during closing of the opening for the conventional case without compensation for a longer opened state duration of the component and the case according to the invention with compensation for a longer opened state duration of the component within defined travel paths RP1 and RP2, in which the component may contact and press the seals shown in FIG. 2. A case of a longer opened state duration of the component is assumed in FIG. 3.

PREFERRED EMBODIMENT(S) OF THE INVENTION

[0065] In the following description of a preferred exemplary embodiment, it should be taken into consideration that the present disclosure of the various aspects is not restricted to the details of the construction and the arrangement of the components, as they are shown in the following description and in the figures. All exemplary embodiments, even those not shown in the figures, can be put into practice or carried out in various ways. It should furthermore be taken into consideration that the expression and terminology used here is only used for the purpose of the specific description and these should not be interpreted by the person skilled in the art as such in a restrictive manner. Furthermore, in the following description, the same reference signs denote the same or similar features or objects in the figures, with the result that, in some cases, a repeated detailed description thereof is dispensed with in order to preserve the compactness and clarity of the illustration.

[0066] FIG. 1 shows an overview of a device 1 for detecting a pinching situation according to an exemplary embodiment of the invention. The device 1 comprises an electronic control unit 10 (ECU) and a motor unit 50 having an electric motor 55 which is operated by the electronic control unit 10. For this purpose, the electronic control unit 10 in FIG. 1 has a circuit (not shown) which comprises, for example, electric switches (e.g. power transistors) in a known manner, which make it possible to operate or control the motor in pulse width modulation (PWM). The electric motor 55 may be a BLDC motor. In this case, the motor is supplied with a voltage from a vehicle battery (not shown) and the power of the motor is determined via the pulse widths defined by driving the power transistors. This driving is performed by a microcontroller, which is, inter alia, in this regard configured with a software application 12.

[0067] The electronic control unit 10 is further connected to a central control module 40 (e.g. BCM) via a vehicle bus 45, for example a CAN bus or a LIN bus, etc. As is yet to be explained, this serves in the present case only to provide a system time.

[0068] The software application 12 comprises, inter alia, a pinch protection module 14. The pinch protection module 14 is responsible for controlling the power transistors, with which the electric motor 55 is in turn operated. The pinch protection module 14 comprises two module units, namely a first module unit 16, which controls the actual operation for moving the component 60 driven by the electric motor 55 and, during this, performs a pinch detection, and a second module unit 18, which performs a calculation of a compensation accounting for a duration of an opened state and transmits the result to the first module unit 16 so that the latter performs its monitoring with adapted values.

[0069] According to the exemplary embodiment shown in FIG. 1, the operation is as follows:

[0070] At a point in time t1, a passenger or the driver of the vehicle actuates an operating module (not shown) in order to move the component 60 (reference sign 72), so that the latter releases an opening 70 of the vehicle. For example, such opening 70 may be related to a glass roof as shown in FIG. 2 as the adjustable component 60. This is signaled to the electronic control unit 10 via the central control module 40 and the vehicle bus 45 (box 1). The first module unit 6 then operates the electric motor 55 in order to move the component 60, so that the roof is opened. At the same time, the second module unit 18 initiates a query to the central control unit 40 via the vehicle bus with a request for a system time. The central control unit 40 responds with a time stamp containing the then current system time (box 2), which is stored in the memory 30. In the exemplary embodiment, memory 30 may be a non-volatile memory, or at least for this time stamp a non-volatile partial area of the memory 30 optionally additionally comprising a RAM (random-access memory).

[0071] At a second point in time t2, the operating module is actuated again in order to close the roof. The information is transmitted to the electronic control unit 10 in an analogous manner via the central control module 40 and the vehicle bus 45. The software application or the first module unit 16 of the pinch protection module 14 then sets the component into a movement 72 for closing the opening by operating the electric motor 55.

[0072] In order to detect a pinching situation, a value for the trigger threshold P.sub.th for the closing force is read out from the memory 30 by the first module unit 16. In the exemplary embodiment, the trigger threshold P.sub.th has, considered in absolute terms and without compensation, e.g. a constant value for the entire travel path R.sub.tot of the component 60, which can be seen in the diagram of FIG. 3 to be explained below. The closing force assigned to the trigger threshold P.sub.th varies in absolute values, for which reason the scale of the values for the closing force shown in FIG. 3 is related to the trigger threshold P.sub.th for each movement position or is set into a ratio, so that the trigger threshold P.sub.th in the illustration of FIG. 3 also assumes a constant value in the case with compensation (lower curve within the travel paths R.sub.P1 and R.sub.P2).

[0073] During the movement of the component 60, the closing force P.sub.act is calculated for a multiplicity of successive movement positions S.sub.pos. For this purpose, the first module unit continuously reads out values correspondingly measured by the motor voltage sensor 51 and the angular velocity sensor 52 (e.g. a Hall sensor) for the respective current movement position and calculates the current closing force therefrom. A ratio of the current closing force with regard to the closing force of the trigger threshold is then calculated. The current movement position is calculated by the first module unit from information which it receives from the position sensor 53 of the motor unit 50.

[0074] The first module unit 16 is now in possession both of the trigger threshold and of the respective current value of the closing force.

[0075] At the same time as the signal is received from the central control module 40 for the closing of the roof, the second module unit 18 reads out positions for path sections RP1 and RP2 from the memory 30, which are stored there in advance and define path sections with regard to the component 60 in which the latter may come into pressing contact with seals 91-93 in the opening 70 (boxes 5a, 5b). For all movement positions calculated by the first module unit 16 (which it then also receives from the latter, box 8), the second module unit now checks in each case whether the movement position currently supplied by the first module unit lies in the respective path section.

[0076] Furthermore, the second module unit 18 initiates a second query to the central control module 40 with a request for a system time and receives a second time stamp containing a second system time (box 3). For this purpose, the second module unit 16 reads out the first time stamp from the memory 30 (box 4) and calculates a time difference which corresponds to the opening time of the roof (duration of the uninterrupted release of the opening 70 by the component).

[0077] Depending on the above check result (current movement position within the respective path section: Yes), the second module unit 18 now calculates a compensation which is dependent on the time duration of the opened state and with which the normalized current value of the closing force is to be adapted and transmits this value to the first module unit 16, which carries out the adaptation.

[0078] In particular, FIG. 3 shows in a diagram a comparison of the currently determined closing force P.sub.act (based on the trigger threshold, which assumes a constant value) plotted over the travel path R.sub.tot of the component during closing of the opening for the conventional case without compensation for a longer opened state duration of the component and the case according to the invention with compensation for a longer opened state duration of the component within defined travel paths R.sub.P1 and R.sub.P2, in which the component may contact and press the seals 91, 92, 93 shown in FIG. 2. Outside the two travel paths, no compensation takes place and the corresponding curves are identical.

[0079] In order to explain the concept of the invention, a case of a longer opened state duration of the component is shown in FIG. 3. Within the travel paths R.sub.P1 and R.sub.P2, the current value of the closing force P.sub.act increases sharply if no compensation is carried out. As can be seen, the respective upper curve exceeds the trigger threshold P.sub.th a total of four times (once in the travel path R.sub.P1 and three times in the travel path R.sub.P2), which would lead to faulty reversal without compensation.

[0080] During the compensation or adaptation, the trigger threshold P.sub.th is adapted. In the illustration of FIG. 3, the closing force is related to the trigger threshold P.sub.th, for which reason the trigger threshold itself in FIG. 3 assumes the same level in the compensated state as in the uncompensated state. In the illustration, by contrast, the closing force P.sub.act related to the trigger threshold changes if the trigger threshold P.sub.th is adapted. It can be seen clearly in FIG. 3 that, as a result of the compensation, the closing force P.sub.act related to the trigger threshold P.sub.th decreases to a considerable extent relative to the trigger threshold, with the result that the trigger threshold P.sub.th is no longer exceeded and faulty reversal is thereby avoided.

LIST OF REFERENCE SIGNS

[0081] 1 Device for detecting a pinching situation [0082] 10 electronic control unit (ECU) [0083] 12 software application [0084] 14 pinch protection module [0085] 16 first module unit for pinch detection [0086] 18 second module unit for compensation accounting for a duration of an opened state [0087] 22 incorrect detection [0088] 30 memory [0089] 50 motor unit [0090] 51 motor voltage sensor [0091] 52 angular velocity sensor [0092] 53 position sensor [0093] 54 temperature sensor [0094] 60 component [0095] 62 additional component [0096] 64 gap [0097] 70 opening [0098] 72 movement of the component [0099] 91 first seal [0100] 92 second seal [0101] 93 third seal