JP2023013137A - Pinching detector for vehicle - Google Patents

Abstract

To provide a pinching detector for a vehicle, that suppresses degradation in pinching detection accuracy despite that applied voltage is raised in the midway.SOLUTION: CPU 62f, 62r drive motors 52f, 52r, when receiving an instruction for tilting seat backs 14f, 14r forward in a vehicle. When the seat back 14f is displaced to a state where interference does not occur between a head rest 16f and a head rest 16r, the CPU 62f issues a notification to that effect. When this notification is received, the CPU 62r raises a voltage to be applied to the motor 52r. The CPU 62r raises an upper limit of current of the motor 52r not determined as pinching, after raising the voltage compared to before raising it.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an entrapment detection device for a vehicle.

For example, Japanese Unexamined Patent Application Publication No. 2002-200002 describes a vehicle opening/closing member control device that drives an opening/closing member that opens and closes an opening of a vehicle. This control device executes a pinch detection for detecting a foreign object caught between the opening and the opening/closing body as the opening/closing body is driven. In this control device, pinch detection is executed based on the current of the motor that drives the opening/closing member.

JP 2020-147950 A

By the way, when a movable member of a vehicle such as an opening/closing body is displaced by the power of a motor, there may be a demand to increase the power of the motor halfway through. In that case, the current flowing through the motor changes, which may reduce the accuracy of pinch detection.

Means for solving the above problems and their effects will be described below.
1. Applied to a vehicle provided with a movable member and a motor for displacing the movable member, the movable member being any one of an opening and closing body for opening and closing an opening of the vehicle and a movable portion of the seat. and executing an instruction acquisition process, a displacement process, and an entrapment detection process, the instruction acquisition process being a process of acquiring an instruction to displace the movable member, and the displacement process being the When the instruction is obtained by the instruction obtaining process, the process includes driving the motor to displace the movable member, and includes an applied voltage increasing process, wherein the applied voltage increasing process includes driving the motor to displace the movable member. The pinch detection process is a process for increasing the voltage applied to the terminals of the motor when the movable member is displaced. The entrapment detection device for a vehicle includes processing for detecting that an entrapment has occurred, and processing for increasing the upper limit of the detection value not determined as entrapment after the rise of the applied voltage than before the rise.

The current flowing through the motor has a positive correlation with the value obtained by subtracting the induced voltage due to rotation of the motor from the voltage applied to the terminals of the motor. On the other hand, when pinching occurs, the force that prevents the displacement of the movable member increases, so the force that prevents the rotation of the motor increases. As a result, the induced voltage of the motor decreases due to the deceleration of the motor, and the current flowing through the motor increases. Therefore, entrapment can be detected based on the magnitude of the motor current.

By the way, in the above configuration, the voltage applied to the terminals of the motor increases during the displacement of the movable member. In that case, the current of the motor increases even though there is no entrapment. Therefore, if the upper limit value of the current at which the pinching is not determined before and after the applied voltage is increased, the pinching detection accuracy is lowered. Therefore, in the above configuration, the upper limit value of the current that is not determined to be pinching is set larger after the applied voltage rises than before the rise. As a result, even when the applied voltage is increased in the middle, it is possible to suppress the deterioration of the entrapment detection accuracy.

2. The entrapment detection processing includes determination current value calculation processing and determination processing, and the determination current value calculation processing calculates a determination current value, which is a current value used for determination of the entrapment, based on the detection value. When the applied voltage is high, the determination current value is set to a smaller value than when the applied voltage is low relative to the magnitude of the detection value, and the determination processing includes the determination current 2. The entrapment detection device for a vehicle according to the above 1, wherein the process of determining whether or not the entrapment has occurred is performed based on a comparison between the value and the judgment value.

When the applied voltage is high, the determination current value is smaller than when the applied voltage is low, relative to the magnitude of the detected value. Therefore, even if the detected value increases due to an increase in the applied voltage, it is possible to suppress the current value for determination calculated based on the detected value from increasing. Therefore, when determining whether or not the detected value exceeds the upper limit by comparing the current value for determination and the determination value, the upper limit can be made larger after the applied voltage rises than before the rise.

3. The determination current value calculation processing includes replacement processing, wherein the replacement processing increases the determination current value each time used for determination of the entrapment detection for a predetermined period after the applied voltage is increased. 3. The entrapment detection device for a vehicle according to the above 2, wherein the processing is to replace the value according to the applied voltage in the previous step.

Although the current of the motor increases when the applied voltage is increased, there is a response delay in increasing the current flowing through the motor due to the inductance of the motor coil or the like. Therefore, when determining the current value for determination according to the value after the increase of the applied voltage immediately after the increase of the applied voltage, the current value for determination tends to decrease once. Therefore, for example, when an entrapment occurs but the applied voltage rises at a timing when the entrapment has not yet been detected, the increase in the judgment current value due to the entrapment is offset by the above-mentioned factors, There is a concern that the detection of entrapment may be delayed. Therefore, in the above configuration, for a predetermined period after the applied voltage is increased, the determination current value is calculated according to the applied voltage before being increased. As a result, it is possible to prevent the pinch detection from being delayed.

4. 4. The entrapment detection device for a vehicle according to 3 above, wherein the predetermined period is a period in which the determination current value calculated based on the increased applied voltage is lower than the determination current value before the applied voltage is increased. .

With the above configuration, it is possible to easily set the end point of the period in which the current value for determination based on the applied voltage after the increase is largely decreased due to the response delay of the motor current with respect to the increase of the applied voltage.
5. The determination processing is processing for determining that the entrapment has occurred when a difference between the first current value and the second current value corresponding to each of the pair of detection values sampled at different timings exceeds a threshold value. , the first current value and the second current value are the determination current values calculated based on the detection values at different timings, and the smaller one of the first current value and the second current value; 5. The entrapment detection device for a vehicle according to any one of 2 to 4 above, wherein the determination value is a value obtained by adding the threshold value to the threshold value.

The force required to displace the movable member fluctuates depending on aging, temperature, and the like of the movable member. Therefore, even if the applied voltage is the same, the rotational speed of the motor when displacing the movable member fluctuates depending on aging, temperature, and the like of the movable member. Further, the resistance value of the current distribution path of the motor fluctuates depending on the temperature of the distribution path and the like. Therefore, even if the applied voltage is the same, the rotation speed of the motor when displacing the movable member varies depending on the temperature of the distribution channel and the like. Thus, the rotation speed of the motor when no entrapment occurs varies depending on the various factors described above. Therefore, the current of the motor when no entrapment occurs also fluctuates due to the various factors described above. Therefore, if the determination value corresponding to the upper limit value is set to a fixed value for each applied voltage, it tends to be difficult to improve the detection accuracy of entrapment.

Therefore, in the above configuration, a value obtained by adding a threshold value to the smaller one of the first current value and the second current value is used as the determination value. In that case, the lesser is the current flowing through the motor when there is no pinching, a value that reflects the various factors discussed above. Therefore, the determination value can be set to an appropriate value that takes into account the various factors described above.

6. A voltage of a DC voltage source is applied to the motor via a switching element, the displacement process drives the motor by operating the switching element, and the applied voltage increasing process includes the switching element. 6. The vehicular entrapment detection device according to 5 above, wherein the duty ratio of the ON time with respect to the cycle of the ON/OFF operation of the element is increased from the first duty ratio to the second duty ratio.

Even if the duty ratio is the same, if the magnitude of the voltage of the DC voltage source is different, the voltage applied to the motor will be different. Therefore, when the applied voltage increasing process increases the duty ratio from the first duty ratio to the second duty ratio, the actual applied voltage at the first duty ratio and the actual applied voltage at the second duty ratio are the DC voltage source depends on the voltage magnitude of Therefore, an appropriate value for the current flowing through the motor when the duty ratio is set to the first duty ratio and the second duty ratio also depends on the magnitude of the voltage of the DC voltage source. Therefore, when pinching is detected by comparing the magnitude of the current flowing through the motor with a fixed value, the detection accuracy tends to be low. Therefore, it is particularly effective to use the difference between the first current value and the second current value.

7. The entrapment detection processing includes minimum value update processing, and the minimum value update processing changes the first current value to the current value when the value corresponding to the current detection value is smaller than the first current value. 7. The entrapment detection device for a vehicle according to 5 or 6 above, wherein the second current value is a value corresponding to the detected value sampled each time.

In the above configuration, the first current value is a value corresponding to the minimum detected value. Therefore, the difference between the first current value and the second current value when entrapment occurs is a value that highly accurately indicates the amount of increase in motor current caused by entrapment. Therefore, pinching can be detected with high accuracy based on the difference between the first current value and the second current value exceeding the threshold value.

8. The first current value and the second current value are values corresponding to the pair of detection values sampled at each of a pair of timings separated by a specified period, and the specified period is during which the motor 7. The vehicular entrapment detection device according to 5 or 6 above, wherein the rotation period is a predetermined angle.

When the torque of the motor is converted into a force that displaces the movable member, the magnitude of the load torque applied to the motor may periodically fluctuate due to the mechanical characteristics of the power transmission path of the motor. In that case, the current flowing through the motor will vary with variations in the load torque regardless of whether pinching has occurred. Therefore, in the above configuration, the first current value and the second current value are determined according to each of a pair of detection values sampled at each of a pair of timings separated by a prescribed period. Therefore, it is possible to reduce the influence of the periodic fluctuation of the load torque on the difference between the first current value and the second current value. Therefore, in the above configuration, it is possible to detect entrapment with high accuracy based on the fact that the difference between the first current value and the second current value exceeds the threshold value.

The figure which shows the structure of the seat of the vehicle, and a control apparatus concerning one Embodiment. FIG. 4 is a side view showing a target displacement state of the seatback in the same embodiment; FIG. 4 is a flowchart showing the procedure of processing executed by the front ECU according to the embodiment; FIG. The side view which illustrates interference of the headrest in the same embodiment. FIG. 4 is a flow chart showing the procedure of processing executed by the rear ECU according to the embodiment; FIG. FIG. 4 is a flow chart showing the procedure of processing executed by the rear ECU according to the embodiment; FIG. FIG. 4 is a flow chart showing the procedure of processing executed by the rear ECU according to the embodiment; FIG. 4 is a time chart exemplifying transition of current values for determination according to the embodiment; The side view which illustrates the movable member concerning the modification of the said embodiment.

An embodiment will be described below with reference to the drawings.
FIG. 1 shows the configuration of a seat and a control device in a vehicle.
A rear seat 10r shown in FIG. 1 is used as a rear seat of a vehicle. The rear seat 10r has a seat cushion 12r, a seat back 14r, and a headrest 16r. The headrest 16r is provided at the upper end of the seatback 14r. Two lower rails 20r extending in the longitudinal direction of the vehicle are provided in parallel on the floor portion 30 of the vehicle. Upper rails 22r are attached to the lower rails 20r and are relatively movable on the lower rails 20r in the longitudinal direction of the vehicle. The seat cushion 12r is supported on each upper rail 22r. The seat cushion 12r is relatively movable in the longitudinal direction of the vehicle on the lower rail 20r together with the upper rail 22r.

The front seat 10f is used as a front seat of a vehicle. The front seat 10f includes a seat cushion 12f, a seat back 14f, and a headrest 16f. In the present specification and drawings, reference numerals for members relating to the front seat 10f are followed by "f", while reference numerals for members relating to the rear seat 10r are denoted by "r". there is Here, among the members relating to the front seat 10f, the members relating to the rear seat 10r correspond to the members relating to the rear seat 10r. That is, the seat cushion 12f, the seatback 14f, and the headrest 16f correspond to the seat cushion 12r, the seatback 14r, and the headrest 16r, respectively.

The seat cushion 12f is relatively movable in the longitudinal direction of the vehicle on the lower rail 20f integrally with the upper rail 22f.
The rear seat 10r is provided with a slide actuator 40r and a reclining actuator 50r. The slide actuator 40r slides the seat cushion 12r in the longitudinal direction of the vehicle with the power of the motor 42r. The reclining actuator 50r changes the tilt angle of the seatback 14r by the power of the motor 52r. Specifically, the reclining actuator 50r rotationally displaces the upper end side of the seat back 14r about the shaft provided on the seat cushion 12r side of the seat back 14r.

The reclining actuator 50r includes a motor 52r and a drive circuit 54r. Motor 52r is a DC motor. The drive circuit 54r is a drive circuit with two sets of half bridge circuits. That is, one of the two terminals of the motor 52r is connected to the connection point of the switching element SW1 and the switching element SW2 that constitute the first half bridge circuit. Further, the connection point of the switching element SW3 and the switching element SW4 that constitute the second half bridge circuit is connected to the other terminal. The positive terminal of the battery B is connected to the switching elements SW1 and SW3 of the driving circuit 54r, and the switching elements SW2 and SW4 are grounded.

The slide actuator 40r includes a drive circuit 44r for driving the motor 42r in addition to the motor 42r.
The front seat 10f is provided with a slide actuator 40f and a reclining actuator 50f. The slide actuator 40f has a motor 42f and a drive circuit 44f. The reclining actuator 50f also includes a motor 52f and a drive circuit 54f.

The rear ECU 60r operates the slide actuator 40r and the reclining actuator 50r in order to control the amount of control of the rear seat 10r as a controlled object. The control amounts at this time are the position of the seat cushion 12r and the inclination angle of the seatback 14r. The rear ECU 60r refers to the output signal Sm of the rotation angle sensor 56r when controlling the control amount. The output signal Sm is a pulse signal output each time the rotation angle of the motor 42r reaches a predetermined angle. The rear ECU 60r also refers to the detected value i of the current flowing through the motor 52r detected by the current sensor 58r.

In the rear ECU 60r, the CPU 62r, ROM 64r, storage device 66r, and peripheral circuit 68r can communicate with each other through a communication line 69r. Here, the peripheral circuit 68r includes a circuit for generating a clock signal that defines internal operations, a power supply circuit, a reset circuit, and the like. The rear ECU 60r controls the control amount by the CPU 62r executing a program stored in the ROM 64r.

The front ECU 60f operates the slide actuator 40f and the reclining actuator 50f in order to control the amount of control of the front seat 10f as a controlled object. In the front ECU 60f, the CPU 62f, ROM 64f, storage device 66f, and peripheral circuit 68f can communicate with each other via a communication line 69f.

The front ECU 60 f and the rear ECU 60 r can communicate with each other via the in-vehicle network 70 . Also, the front ECU 60f and the rear ECU 60r acquire the output signal of the user interface 72 via the in-vehicle network 70. FIG. The user interface 72 allows the user to perform an input operation to give an instruction to adjust the control amount of the front seat 10f and the control amount of the rear seat 10r. This instruction includes an instruction to tilt forward the seat back 14f of the front seat 10f and the seat back 14r of the rear seat 10r, as shown in FIG. This instruction is hereinafter referred to as the convolution instruction. In the following, the details will be described in the order of "processing in response to a folding instruction", "preprocessing for entrapment detection processing associated with convolution processing", and "entrapment detection processing".

(Processing according to convolution instructions)
FIG. 3 shows the procedure of processing executed by the front ECU 60f. The processing shown in FIG. 3 is implemented by the CPU 62f repeatedly executing a program stored in the ROM 64f, for example, at predetermined intervals. Note that, hereinafter, the step number of each process is represented by a number prefixed with “S”.

In the series of processes shown in FIG. 3, the CPU 62f first determines whether or not the convolution flag F1 is "1" (S10). When the convolution flag F1 is "1", it indicates that the processing according to the convolution instruction is being executed, and when it is "0", it indicates that it is not. When the CPU 62f determines that the convolution flag F1 is "0" (S10: NO), the CPU 62f determines whether or not the user interface 72 is operated to instruct convolution (S12). When the CPU 62f determines that the convolution instruction has been issued (S12: YES), it substitutes "1" for the convolution flag F1 (S14). Then, the CPU 62f drives the motor 52f by operating the drive circuit 54f (S16). Then, the CPU 62r determines whether or not a pulse signal, which is an output signal Sm of the rotation angle sensor 56f indicating that the rotation angle of the motor 52f has reached a predetermined angle, has been detected (S18). When determining that the CPU 62f has detected (S18: YES), the CPU 62f updates the total rotation speed Ntot1 of the motor 52f (S20). Here, the total number of revolutions Ntot1 has a one-to-one correspondence with the tilt angle of the seat back 14f. The total number of revolutions Ntot1 is corrected to increase or decrease depending on the direction of rotation of the motor 52f. In this embodiment, it is assumed that the seat back 14f tilts forward as the total number of revolutions Ntot1 increases. Therefore, the CPU 62f increases the total number of rotations Ntot1 in the process of S20.

Next, the CPU 62f determines whether or not the total number of revolutions Ntot1 has reached a predetermined value Ntot1th (S22). The predetermined value Ntot1th corresponds to the inclination angle of the seatback 14f at which the possibility of interference between the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r is eliminated.

FIG. 4 shows an example of interference between the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r. That is, at the time when the folding instruction is issued, the inclination angle of the seat back 14f and the inclination angle of the seat back 14r are freely set by the user, and thus can take various values. Also, the distance between the seat cushion 12f and the seat cushion 12r can take various values. Therefore, when executing processing according to the folding instruction, there is a possibility that the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r interfere with each other.

Returning to FIG. 3, when the CPU 62f determines that the predetermined value Ntot1th has been reached (S22: YES), the CPU 62f notifies the rear ECU 60r to that effect via the in-vehicle network 70 (S24).

On the other hand, when determining that the convolution flag F1 is "1" (S10: YES), the CPU 62f determines whether or not the total rotation speed Ntot1 has reached the target rotation speed Ntot1* (S26). The target rotation speed Ntot1* is set to the total rotation speed Ntot1 when the seat back 14f is in the state shown in FIG. When determining that the target rotation speed Ntot1* has not been reached (S26: NO), the CPU 62f proceeds to the processing of S16. On the other hand, if the CPU 62f determines that the time has been reached (S26: YES), it substitutes "0" for the convolution flag F1 (S28). The CPU 62f then stops the motor 52f (S30).

It should be noted that the CPU 62f temporarily terminates the series of processes shown in FIG. 3 when the processes of S24 and S30 are completed and when the processes of S12, S18 and S22 are negatively determined.

FIG. 5 shows the procedure of processing executed by the rear ECU 60r. The processing shown in FIG. 5 is implemented by the CPU 62r repeatedly executing a program stored in the ROM 64r, for example, at predetermined intervals.

In the series of processes shown in FIG. 5, the CPU 62r first determines whether or not the convolution flag F2 is "1" (S31). When the convolution flag F2 is "1", it indicates that the processing according to the convolution instruction is being executed, and when it is "0", it indicates that it is not. When the CPU 62r determines that the convolution flag F2 is "0" (S31: NO), it determines whether or not the user interface 72 is operated to instruct convolution (S32). If the CPU 62r determines that the convolution instruction has been issued (S32: YES), it substitutes "1" for the convolution flag F2 (S34). Then, the CPU 62r determines whether or not notification has been made by the process of S24 (S36). If the CPU 62r determines that it has not been done (S36: NO), it determines whether or not the total number of rotations Ntot2 of the motor 52r is equal to or less than a predetermined value Ntot2th (S38). The total number of revolutions Ntot2 has a one-to-one correspondence with the tilt angle of the seatback 14r. The predetermined value Ntot2th is set to the maximum value of the total number of revolutions Ntot2 at which there is no possibility of interference between the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r.

If the CPU 62r determines that it is equal to or less than the predetermined value Ntot2th (S38: YES), it substitutes the first duty ratio DL for the duty ratio D (S40). The duty ratio D indicates the ratio of the ON time to the PWM cycle for turning ON/OFF the switching element SW2 or the switching element SW4.

Then, the CPU 62r drives the drive circuit 54r according to the duty ratio D (S42). That is, the CPU 62r controls the rotation direction of the motor 52r by selecting whether to turn on the switching elements SW1 and SW4 or to turn on the switching elements SW3 and SW2. Further, the CPU 62r turns on/off the switching element SW2 or the switching element SW4 at the duty ratio D. FIG.

The CPU 62r determines whether or not a pulse signal, which is the output signal Sm of the rotation angle sensor 56r indicating that the rotation angle of the motor 52r has reached a predetermined angle, has been detected (S46). If the CPU 62r determines that it has been detected (S46: YES), it updates the total rotation speed Ntot2 of the motor 52r (S48). Here, the total number of revolutions Ntot2 is corrected to increase or decrease depending on the direction of rotation of the motor 52r. In the present embodiment, it is assumed that the seatback 14r tilts forward as the total number of revolutions Ntot2 increases. Therefore, the CPU 62r increases the total number of rotations Ntot2 in the process of S48.

On the other hand, if the CPU 62r determines that the notification has been made by the process of S24 (S36: YES), it substitutes the second duty ratio DH for the duty ratio D (S50). The second duty ratio DH is set to a value greater than the first duty ratio DL. In this embodiment, in particular, the second duty ratio DH is set to "100". Then, the CPU 62r shifts to the process of S42. As a result, the drive circuit 54r is operated according to the second duty ratio DH.

In the process of S16 in FIG. 3, the motor 52f is driven by operating the drive circuit 54f with the duty ratio D set to the second duty ratio DH.
When the CPU 62r determines that the convolution flag F2 is "1" (S31: YES), the CPU 62r determines whether or not the total rotation speed Ntot2 has reached the target rotation speed Ntot2* (S52). The target rotation speed Ntot2* is set to the total rotation speed Ntot2 when the seat back 14r is in the state shown in FIG. When determining that the target rotation speed Ntot2* has not been reached (S52: NO), the CPU 62r proceeds to the process of S36. On the other hand, if the CPU 62r determines that the time has been reached (S52: YES), it substitutes "0" for the convolution flag F2 (S54). The CPU 62r stops the motor 52r when completing the process of S54 and when making a negative determination in the process of S38 (S56).

It should be noted that the CPU 62r temporarily terminates the series of processes shown in FIG. 5 when the processes of S48 and S56 are completed and when a negative determination is made in the processes of S32 and S46.
(Pre-processing of entrapment detection processing associated with convolution processing)
FIG. 6 shows the procedure of the pretreatment. The processing shown in FIG. 6 is implemented by the CPU 62r repeatedly executing a program stored in the ROM 64r, for example, at predetermined intervals.

In the series of processes shown in FIG. 6, the CPU 62r first acquires the detected value i of the current flowing through the motor 52r (S60). Next, the CPU 62r calculates the post-filter current ifil0 by low-pass filtering the detection value i (S62). Then, the CPU 62r substitutes a value obtained by multiplying the current ifil0 after filtering by "100/D" into the current value for determination ifil1 (S64). "100/D" is a coefficient for reducing the difference in magnitude between the detected value i and the filtered current ifil0 due to the difference in the duty ratio D. That is, the voltage applied to the motor 52r is greater when the duty ratio D is the second duty ratio DH than when the duty ratio D is the first duty ratio DL. In other words, the effective value of the voltage applied to the motor 52r increases. Therefore, the detected value i and the filtered current ifil0 are larger at the second duty ratio DH than at the first duty ratio DL. On the other hand, the coefficient "100/D" is smaller when the duty ratio D is the second duty ratio DH than when the duty ratio D is the first duty ratio DL. Therefore, the determination current value ifil1 does not change significantly between when the duty ratio D is the first duty ratio DL and when it is the second duty ratio DH.

Next, the CPU 62r determines whether or not it is time to switch the duty ratio D from the first duty ratio DL to the second duty ratio DH (S66). If the CPU 62r determines that it is time to switch (S66: YES), it substitutes the determination current value ifil1 calculated in the process of S64 immediately before the same timing for the reference value ifillast (S68).

On the other hand, when the CPU 62r determines that it is not the switching timing (S66: NO), it determines whether the determination current value ifil1 is smaller than the reference value ifillast (S70). If the CPU 62r determines that it is small (S70: YES), it substitutes a value obtained by multiplying the current ifil0 after filtering by "100/DL" into the current value for determination ifil1 (S72).

It should be noted that the CPU 62r once ends the series of processes shown in FIG. 6 when the processes of S68 and S72 are completed, and when the negative determination is made in the process of S70.
(Pinch detection processing)
FIG. 7 shows the procedure of the entrapment detection process. The processing shown in FIG. 7 is implemented by the CPU 62r repeatedly executing a program stored in the ROM 64r, for example, at predetermined intervals.

In the series of processes shown in FIG. 7, the CPU 62r first substitutes the smaller one of the minimum value ifilmin and the determination current value ifil1 for the minimum value ifilmin (S80). Then, the CPU 62r determines whether or not the value obtained by subtracting the minimum value ifilmin from the determination current value ifil1 is greater than the threshold value Δth1 (S82). This processing is processing to determine whether or not pinching has occurred due to the displacement of the seat back 14r. That is, when pinching occurs, the force required to displace the seat back 14r increases, and the rotational speed of the motor 52r decreases. As a result, the induced voltage of the motor 52r decreases, and the magnitude of the current flowing through the motor 52r increases.

If the CPU 62r determines that it is greater than the threshold value Δth1 (S82: YES), it determines that entrapment has been detected (S90). The CPU 62r then forcibly stops the motor 52r (S92).

On the other hand, if the CPU 62r determines that it is equal to or less than the threshold value Δth1 (S82: NO), it determines whether or not the motor 52r has rotated for the pulsation period ΔNtot2 or more after starting the convolution process (S84). The pulsation period ΔNtot2 is the period of variation due to mechanical factors in the magnitude of the force required to displace the seatback 14r. The pulsation period ΔNtot2 is preliminarily adapted as a value specific to the mechanism for displacing the seatback 14r, such as the number of gear teeth.

If the CPU 62r determines that the rotation is equal to or greater than the pulsation period ΔNtot2 (S84: YES), it substitutes the determination current value ifil1 sampled before the pulsation period ΔNtot2 into the pre-cycle current value ifilr (S86). Then, the CPU 62r determines whether or not the absolute value of the value obtained by subtracting the pre-cycle current value ifilr from the determination current value ifil1 is greater than the threshold value Δth2 (S88). This process is also a process of determining whether or not pinching has occurred due to the displacement of the seat back 14r.

If the CPU 62r determines that it is greater than the threshold Δth2 (S88: YES), the process proceeds to S90.
It should be noted that the CPU 62r once ends the series of processes shown in FIG. 7 when the process of S92 is completed and when the negative determination is made in the processes of S84 and S88.

Here, the action and effect of this embodiment will be described.
FIG. 8 exemplifies transition of the determination current value ifil1. As shown in FIG. 8, when the duty ratio D switches from the first duty ratio DL to the second duty ratio DH at time t1, the CPU 62r substitutes the determination current value ifil1 immediately before that for the reference value ifillast.

Here, when the first duty ratio DL is switched to the second duty ratio DH, the filtered current ifil0 increases. However, even if the effective value of the voltage increases, a response delay occurs due to the inductance of the coil of the motor 52r until the current flowing through the motor 52r reaches a steady value. Therefore, when the current value for determination ifil1 is calculated using the coefficient "100/DH", the current value for determination ifil1 decreases to the reference value ifillast due to the decrease in the coefficient "100/D" at time t1. be smaller than Therefore, the CPU 62r multiplies the post-filter current ifil0 by the coefficient "100/DL" while the determination current value ifil1 calculated using the coefficient "100/DH" is smaller than the reference value ifillast. Substitute ifil1. Then, the CPU 62r adopts the determination current value ifil1 calculated using the coefficient "100/DH" after time t2 when the determination current value ifil1 calculated using the coefficient "100/DH" is equal to or greater than the reference value ifillast. do.

FIG. 8 shows that the current flowing through the motor 52r becomes a steady value at time t3. Incidentally, before time t1, the current flowing through the motor 52r has a steady value when the duty ratio D is the first duty ratio DL. As shown in FIG. 8, in the present embodiment, the difference between the steady state value of the determination current value ifil1 at the first duty ratio DL and the steady state value of the determination current value ifil1 at the second duty ratio DH is sufficiently small. .

On the other hand, as shown in FIG. 8, for the filtered current ifil0, the steady-state value IH at the second duty ratio DH is considerably larger than the steady-state value IL at the first duty ratio DL. Therefore, for example, when two values sampled at different timings in the process of S82 are used as the filtered current ifil0 instead of the determination current value ifil1, the positive determination is made after the second duty ratio DH. easier to be Therefore, for example, if the threshold value Δth1 is set to an appropriate value for the first duty ratio DL, there is a risk of erroneous determination that an entrapment has occurred at the second duty ratio DH even though the entrapment has not actually occurred. There is Further, when the threshold value Δth1 is set to an appropriate value for the second duty ratio DH, there is a risk of erroneous determination that entrapment has not occurred at the first duty ratio DL even though entrapment has actually occurred. be.

This is because although the upper limit of the magnitude of the current at which it should not be determined that entrapment has occurred varies according to the magnitude of the duty ratio D, the upper limit is fixed when the filtered current ifil0 is used. This is because That is, if it is appropriate to set a value obtained by adding the threshold value Δth1 to the steady-state value as the upper limit value, the upper limit value of the first duty ratio DL should be a value larger than the steady-state value IL by a predetermined amount. The upper limit value of the duty ratio DH should be a value larger than the steady-state value IH by a predetermined amount.

On the other hand, according to the present embodiment, by using the determination current value ifil1, the upper limit value of the filtered current ifil0 at which it is not determined that entrapment has occurred in the process of S82 is as follows. That is, in the first duty ratio DL, if the minimum value ifilmin is considered to be about the steady-state value IL, it is about "IL+(DL/100)Δth1". On the other hand, in the second duty ratio DH, if the minimum value ifilmin is considered to be about the stationary value IL, it is about "(100/DL).IL+.DELTA.th1." In this embodiment, "IL>Δth1". Therefore, by switching the duty ratio D to the second duty ratio DH, the upper limit value is increased. By the way, this argument holds for the detected value i as well. That is, in the present embodiment, the upper limit of the detection value i at which it is not determined that an entrapment has occurred is larger at the second duty ratio DH than at the first duty ratio DL.

Therefore, according to the present embodiment, even if the duty ratio D is changed during displacement of the seat back 14r, pinching can be detected with high accuracy.
According to the present embodiment described above, the actions and effects described below can be obtained.

(1) Presence or absence of entrapment was determined based on the degree to which the determination current value ifil1 exceeded the minimum value ifilmin and the absolute value of the difference between the determination current value ifil1 and the pre-period current value ifilr. As a result, the upper limit value of the detected value i and the filtered current ifil0 at which it is not determined that the object is pinched can be adjusted to appropriate values according to various factors other than the duty ratio D that change the magnitude of the current. That is, for example, it can be adjusted to an appropriate value according to changes in the rear seat 10r over time, the temperature of the rear seat 10r, the temperature of the current distribution path of the motor 52r, the terminal voltage of the battery B, and the like. Therefore, compared to the case where the upper limit value is fixed for each duty ratio D, pinch detection can be calculated with higher accuracy.

In other words, the force required to displace the seat back 14r varies depending on aging and temperature of the rear seat 10r. Therefore, even if the voltage applied to the motor 52r is the same, the rotation speed of the motor 52r when displacing the seat back 14r varies depending on aging and temperature of the rear seat 10r. In addition, the resistance value of the current flow path of the motor 52r varies depending on the temperature of the flow path and the like. Therefore, even if the voltage applied to the motor 52r is the same, the rotational speed of the motor 52r when displacing the seat back 14r varies depending on the temperature of the distribution channel and the like. Further, when the terminal voltage of the battery B fluctuates, the rotation speed of the motor 52r fluctuates even if the duty ratio D remains the same. Thus, the rotation speed of the motor 52r when no entrapment occurs varies depending on the various factors described above. Therefore, the current of the motor 52r when no entrapment occurs varies depending on the various factors described above. Therefore, if the upper limit value at which entrapment is not detected is set to a fixed value for each value of the duty ratio D, it tends to be difficult to improve the entrapment detection accuracy.

(2) In the process of S88, the CPU 62r determines whether or not there is an entrapment depending on whether or not the absolute value of the value obtained by subtracting the pre-cycle current value ifilr from the determination current value ifil1 is greater than the threshold value Δth2. As a result, it is possible to determine the presence or absence of entrapment while suppressing the effects of periodic fluctuations in the load torque applied to the motor 52r when displacing the seatback 14r.

(3) The determination current value is defined such that the steady state value of the determination current value ifil1 at the second duty ratio DH is slightly smaller than the steady state value of the determination current value ifil1 at the first duty ratio DL. As a result, it is possible to suppress loosening of the criterion for detecting entrapment after the duty ratio D is changed.

(4) After changing the duty ratio D, if the determination current value ifil1 calculated using the coefficient "100/DH" is less than the reference value ifillast, the coefficient "100/DL" is multiplied by the filtered current ifil0. The resulting value was taken as the determination current value ifil1. This can prevent the minimum value ifilmin from being updated to an inappropriate value. Moreover, entrapment can be detected more quickly than when entrapment detection is masked for a predetermined period after the duty ratio D is changed.

<Correspondence relationship>
Correspondence relationships between the items in the above embodiment and the items described in the "Means for Solving the Problems" column are as follows. Below, the corresponding relationship is shown for each number of the means for solving the problem described in the column of "means for solving the problem". [1] The vehicle entrapment detection device corresponds to the rear ECU 60r. A movable portion of the seat corresponds to the seat back 14r. The instruction acquisition process corresponds to the process of S32. The displacement process corresponds to the processes of S40, S42 and S50. The entrapment detection process corresponds to the processes of S60 to S72 and S80 to S90. The applied voltage increase process corresponds to the process of S50. [2] The determination current value calculation process corresponds to the processes of S60 to S72. The determination process corresponds to the processes of S82 and S88. The determination value corresponds to a value obtained by adding the threshold value Δth1 to the minimum value ifilmin, and a value obtained by adding the threshold value Δth2 to the smaller one of the determination current value ifil1 and the pre-cycle current value ifilr in the process of S88. [3, 4] replacement processing corresponds to the processing of S66 to S72. The predetermined period corresponds to the period from time t1 to t2 in FIG. [5] The first current value corresponds to the minimum value ifilmin in the process of S82, and either the determination current value ifil1 or the pre-cycle current value ifilr in the process of S88. The second current value corresponds to the determination current value ifil1 in the process of S82 and either of the determination current value ifil1 and the pre-period current value ifilr in the process of S88. The threshold corresponds to the threshold Δth1 in the process of S82 and the threshold Δth2 in the process of S88. [6] The switching elements correspond to the switching elements SW1 to SW4. [7] The minimum value update process corresponds to the process of S80. [8] The first current value and the second current value correspond to the determination current value ifil1 and the pre-cycle current value ifilr in the process of S88. The prescribed period corresponds to the pulsation period ΔNtot2.

<Other embodiments>
In addition, this embodiment can be changed and implemented as follows. This embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.

"About current value for judgment"
In the above embodiment, the value obtained by multiplying the post-filtering current ifil0 by "100/D" is used as the determination current value ifil1, but this is not restrictive. For example, a value obtained by multiplying the detected value i by "100/D" may be used as the determination current value ifil1.

The coefficient for setting the determination current value ifil1 to a smaller value when the applied voltage is high than when the applied voltage is low relative to the magnitude of the detected value i is not limited to "100/D". For example, a constant K other than "100" may be used as "K/D". Here, as the constant K, the first duty ratio DL may be used.

It is not essential to set the steady-state value of the determination current value ifil1 at the second duty ratio DH to be greater than the steady-state value of the determination current value ifil1 at the first duty ratio DL.
- The determination current value ifil1 is not limited to the value obtained by multiplying the detected value i or the filtered current ifil0 by a coefficient. For example, the CPU 62r may map-calculate the determining current value ifil1 using map data. Here, as the map data, data having the detected value i or the filtered current ifil0 and the value of the variable indicating the applied voltage as input variables and the determination current value ifil1 as the output variable may be adopted.

- The value of the variable indicating the applied voltage, which is used when calculating the judgment current value ifil1, is not limited to the duty ratio D. For example, as described in the section "Motor" below, when a brushless motor is used as the motor and the applied voltage is sinusoidal, the amplitude value of the applied voltage may be employed.

"About the minimum value update process"
- The minimum value ifilmin is not limited to the minimum value of the judgment current value ifil1 from the start of driving the motor 52r. For example, if the load for displacing the seatback 14r changes according to the position of the seatback 14r, the minimum value ifilmin may be updated for each section in which the load is substantially constant.

"Pinch detection processing"
- It is not essential to set the thresholds Δth1 and Δth2 to fixed values in the processing of S82 and S88. For example, if one of a pair of determination current values ifil1 constituting a comparison target with the thresholds Δth1 and Δth2 is the value at the first duty ratio DL and the other is the value at the second duty ratio DH, You can make it smaller. This can be simply realized by correcting the threshold values Δth1 and Δth2 to values multiplied by “DL/100”.

- For example, in the process of S82, the post-filtering current ifil0 and its minimum value may be used in place of the determination current value ifil1 and its minimum value. In that case, the threshold value Δth1 may be increased by using the rise of the duty ratio D as a trigger. Here, the upper limit value of the filtered current ifil0 that does not detect entrapment is a value obtained by adding the threshold value Δth1 to the minimum value of the filtered current ifil0. Therefore, by increasing the duty ratio D, the upper limit value is changed to a larger value. By the way, as described in the section "Minimum value update process", when the minimum value ifilmin is determined for each section, the process for increasing the threshold value Δth1 is changed as follows. That is, the threshold Δth1 is changed so as to be increased only when the applied voltage is increased after sampling the minimum value ifilmin. Note that it is not essential to use the filtered current ifil0 and its minimum value for the process of increasing the threshold Δth1. For example, the detected value i and its minimum value may be used.

Further, for example, in the process of S88, the threshold value Δth2 may be increased only when the applied voltage is increased within one pulsation period from the execution timing of the process.
"About replacement process"
- The timing for switching the coefficient for calculating the determination current value ifil1 from "100/DL" to "100/DH" is not limited to the timing illustrated in FIG. In other words, the timing at which the predetermined period has elapsed since the applied voltage was increased is not limited to the timing illustrated in FIG. For example, it may be the timing when the current value of the filtered current ifil0 is less than the previous value.

• It is not essential to perform the replacement process. For example, a masking period during which the entrapment detection process is not executed may be provided for a predetermined period after the applied voltage is increased.
"Regarding countermeasures against pinching"
- The processing for coping with the situation in which an entrapment is detected is not limited to the processing of S92. For example, it may be a process of reversing the motor 52r. In order to reverse the rotation of the motor 52r, the rotational speed of the motor 52r must be once set to zero.

- It is not essential that the processing for coping with the detection of entrapment includes the processing for stopping the motor 52r. For example, it may be a process of issuing an alarm by operating a speaker while controlling the torque of the motor 52r to zero.

"Applied voltage increase processing"
The purpose of the process for increasing the voltage applied to the motor 52r is not limited to avoiding interference between the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r. For example, the applied voltage may be reduced during the period required for the user to sense that the seat backs 14f and 14r begin to displace, and then the applied voltage may be increased.

"About moving parts"
A movable member that is a target of pinch detection and that constitutes the seat is not limited to the seat backs 14f and 14r. For example, it may be seat cushions 12f and 12r. That is, pinching may be detected when the upper rails 22f and 22r are displaced relative to the lower rails 20f and 20r.

- A movable member that is a target of pinch detection is not limited to a member that constitutes a sheet. For example, like a slide door 84 shown in FIG. 9, it may be an opening/closing body that opens and closes an opening of a vehicle. A sliding door 84 shown in FIG. 9 opens and closes an opening 82 of the vehicle 80 .

"Pinch detection device"
- The entrapment detection device is not limited to one that includes a CPU and a ROM and executes software processing. For example, a dedicated hardware circuit such as an ASIC may be provided to perform hardware processing at least part of what is software processed in the above embodiments. That is, the entrapment detection device may have any one of the following configurations (a) to (c). (a) A processing device that executes all of the above processes according to a program, and a program storage device such as a ROM that stores the program. (b) A processing device and a program storage device for executing part of the above processing according to a program, and a dedicated hardware circuit for executing the remaining processing. (c) provide dedicated hardware circuitry to perform all of the above processing; Here, there may be a plurality of software execution devices provided with a processing device and a program storage device, or a plurality of dedicated hardware circuits.

"Motor drive circuit"
・The motor drive circuit is not limited to the H-bridge circuit. For example, the motor may be a brushless motor and the drive circuit may be an inverter. In that case, for example, if the motor is a three-phase brushless motor, the inverter should be energized by the 120° energization method. When the switching element is turned on for a period of 120°, the duty ratio D should be 100%. In that case, the duty ratio D can be set to a value less than "100%" by determining the PWM cycle in the same period and turning on/off the switching element. Note that the voltage applied to the motor is not limited to a rectangular wave voltage. For example, the voltage applied to the terminals of the motor may be changed sinusoidally by changing the duty ratio of the inverter sinusoidally. In that case, increasing the applied voltage means increasing the amplitude of the sinusoidal voltage.

"others"
- In FIG. 1, the front ECU 60f and the rear ECU 60r may be integrated.
- In FIG. 1, for example, the vehicle may have three rows of seats. In that case, the rear seat 10r in FIG. 1 may be the rearmost seat or may be the central seat.

10f front seat 10r rear seat 12f, 12r seat cushion 14f, 14r seat back 16f, 16r headrest 50f, 50r reclining actuator 52f, 52r motor 54f, 54r drive circuit 60f front ECU
60r...Rear ECU

Claims (8)

Applied to a vehicle comprising a movable member and a motor for displacing the movable member,
wherein the movable member is one of a movable portion of a seat and an opening/closing body that opens and closes an opening of the vehicle;
executing an instruction acquisition process, a displacement process, and an entrapment detection process,
The instruction acquisition process is a process of acquiring an instruction to displace the movable member,
the displacement process is a process of driving the motor to displace the movable member when the instruction is acquired by the instruction acquisition process, and includes an applied voltage increase process;
The applied voltage increasing process is a process for increasing the voltage applied to the terminals of the motor when the movable member is displaced by driving the motor,
The entrapment detection process is a process for detecting that entrapment has occurred due to displacement of the movable member based on the magnitude of the detected value of the current flowing through the motor, and the upper limit of the detected value that is not determined as the entrapment. An entrapment detection device for a vehicle, including a process of increasing the value after the applied voltage is increased more than before the applied voltage is increased. The entrapment detection processing includes determination current value calculation processing and determination processing,
The determination current value calculation process is a process of calculating a determination current value, which is a current value used for determination of the entrapment, based on the detection value,
When the applied voltage is high, the determination current value is set to a smaller value than when the applied voltage is low, relative to the magnitude of the detected value,
2. The entrapment detection device for a vehicle according to claim 1, wherein said judgment processing is processing for judging whether or not said entrapment has occurred based on a magnitude comparison between said current value for judgment and a judgment value. The determination current value calculation process includes a replacement process,
In the replacement process, for a predetermined period after the applied voltage is increased, the determination current value used for determination of the pinching detection is replaced with a value corresponding to the applied voltage before being increased. An entrapment detection device for a vehicle according to claim 2. 4. The entrapment detection device for a vehicle according to claim 3, wherein the predetermined period is a period in which the current value for determination calculated based on the increased applied voltage is lower than the current value for determination before the applied voltage is increased. The determination processing is processing for determining that the entrapment has occurred when a difference between the first current value and the second current value corresponding to each of the pair of detection values sampled at different timings exceeds a threshold value. ,
The first current value and the second current value are current values for determination calculated based on the detection values at different timings,
5. The entrapment detection device for a vehicle according to claim 2, wherein the determination value is a value obtained by adding the threshold value to the smaller one of the first current value and the second current value. A voltage from a DC voltage source is applied to the motor via a switching element,
the displacement processing includes driving the motor by operating the switching element;
6. The entrapment detection device for a vehicle according to claim 5, wherein the applied voltage increasing process is a process of increasing the duty ratio of the ON time with respect to the cycle of the ON/OFF operation of the switching element from a first duty ratio to a second duty ratio. The entrapment detection process includes a minimum value update process,
The minimum value updating process is a process of updating the first current value to a value corresponding to the current detection value when the value corresponding to the current detection value is smaller than the first current value,
7. An entrapment detection device for a vehicle according to claim 5, wherein said second current value is a value corresponding to said detection value sampled each time. The first current value and the second current value are values corresponding to each of the pair of detection values sampled at each of a pair of timings separated by a specified period,
7. An entrapment detection device for a vehicle according to claim 5 or 6, wherein said prescribed period is a period during which said motor rotates by a predetermined angle.

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