Vehicle Pinch Detection Device

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

[0001] The present invention relates to a pinching detection device for a vehicle.

Background Art

[0002] For example, Patent Document 1 below describes a vehicle opening / closing control device that drives an opening / closing body that opens and closes an opening of a vehicle. This control device executes pinching detection for detecting that a foreign object is pinched between the opening and the opening / closing body when the opening / closing body is driven. In this control device, pinching detection is executed based on the current of a motor that drives the opening / closing body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when displacing a movable member of a vehicle such as an opening / closing body by the power of a motor, a demand may arise to greatly increase the power of the motor halfway. And in that case, since the current flowing through the motor changes, there is a risk that the accuracy of pinching detection will decrease.

Means for Solving the Problems

[0005] Hereinafter, means for solving the above problems and their operational effects will be described. 1. A vehicle clamping detection device applied to a vehicle including a movable member and a motor for displacing the movable member, wherein the movable member is either an opening / closing body for opening and closing an opening of the vehicle or a movable part of a seat, and the device executes an instruction acquisition process, a displacement process, and a pinching 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 increase process is a process of increasing the applied voltage to the terminals of the motor when the movable member is being displaced by driving the motor. The pinching detection process is a process of detecting that pinching has occurred due to the displacement of the movable member based on the magnitude of the detected value of the current flowing through the motor, and includes a process of making the upper limit value of the detected value that is not determined as pinching larger after the increase in the applied voltage than before the increase in the applied voltage.

[0006] The current flowing through the motor has a positive correlation with the value obtained by subtracting the induced voltage associated with the rotation of the motor from the applied voltage to the terminals of the motor. On the other hand, when pinching occurs, the force trying to prevent the displacement of the movable member increases, so the force trying to prevent 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, pinching can be detected based on the magnitude of the current of the motor.

[0007] By the way, in the above configuration, the applied voltage to the terminals of the motor increases during the displacement of the movable member. In that case, even though no pinching has occurred, the current of the motor increases. Therefore, when the upper limit value of the current that is not determined as pinching is made equal before and after the increase in the applied voltage, the detection accuracy of pinching decreases. Therefore, in the above configuration, the upper limit value of the current that is not determined as pinching is made larger after the increase in the applied voltage than before the increase in the applied voltage. Thereby, even when the applied voltage is increased halfway, a decrease in the detection accuracy of pinching can be suppressed.

[0008] 2. The pinching detection process includes a determination current value calculation process and a determination process. The determination current value calculation process is a process of calculating a determination current value, which is a current value used for determining the pinching, based on the detection value. The determination current value is set to be a value that is smaller in proportion to the magnitude of the detection value when the applied voltage is large than when it is small. The determination process is a process of determining whether or not the pinching has occurred based on a comparison of the magnitudes of the determination current value and a determination value. The vehicle pinching detection device according to claim 1 above.

[0009] The above determination current value is set to be a value that is smaller in proportion to the magnitude of the detection value when the applied voltage is large than when it is small. Therefore, even if the detection value increases due to an increase in the applied voltage, it is possible to suppress an increase in the determination current value calculated based on the same detection value. Accordingly, when determining whether or not the detection value exceeds the upper limit value by comparing the magnitudes of the determination current value and the determination value, the upper limit value can be made larger after the increase in the applied voltage than before the increase.

[0010] 3. The determination current value calculation process includes a substitution process. The substitution process is a process of substituting, for each determination current value used for determining the pinching detection during a predetermined period after increasing the applied voltage, a value corresponding to the applied voltage before the increase. The vehicle pinching detection device according to claim 2 above.

[0011] When the applied voltage is increased, the current of the motor increases. However, due to the inductance of the motor coil or the like, there is a response delay for the current flowing through the motor to increase. Therefore, when determining the determination current value according to the value after the increase of the applied voltage immediately after the increase of the applied voltage, the determination current value tends to decrease significantly once. Therefore, for example, when the applied voltage increases at a timing when pinching has occurred but the detection of pinching has not yet been achieved, the increase in the determination current value due to pinching may be offset by the above factors, and there is a concern that the detection of pinching may be delayed. Therefore, in the above configuration, within a predetermined period after increasing the applied voltage, the determination current value is calculated according to the applied voltage before the increase. Thereby, it is possible to suppress the delay in pinching detection.

[0012] 4. The vehicle pinching detection device according to item 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 increasing the applied voltage.

[0013] In the above configuration, the end point of the period in which the determination current value based on the applied voltage after the increase significantly decreases due to the response delay of the motor current to the increase of the applied voltage can be easily set. 5. The determination process is a process of determining that the pinching has occurred when the difference between the first current value and the second current value corresponding to each of a pair of the 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 value obtained by adding the threshold value to the smaller one of the first current value and the second current value is the determination value. The vehicle pinching detection device according to any one of items 2 to 4 above.

[0014] The force required to displace the movable member varies due to the secular change of the movable member, temperature, etc. Therefore, even with the same applied voltage, the rotational speed of the motor when displacing the movable member varies due to the secular change of the movable member, temperature, etc. Also, the resistance value of the current flow path of the motor varies depending on the temperature of the flow path, etc. Therefore, even with the same applied voltage, the rotational speed of the motor when displacing the movable member varies depending on the temperature of the flow path, etc. Thus, the rotational speed of the motor when no pinching occurs varies due to the various factors described above. Therefore, the current of the motor when no pinching occurs also varies due to the various factors described above. For this reason, if the determination value corresponding to the above upper limit value is set as a fixed value for each applied voltage, it tends to be difficult to improve the detection accuracy of pinching.

[0015] Therefore, in the above configuration, a value obtained by adding a threshold value to the smaller of the first current value and the second current value is used as the determination value. In that case, the smaller value is the current flowing through the motor when no pinching occurs, and is a value reflecting the various factors described above. Therefore, the determination value can be set to an appropriate value taking into account the various factors described above.

[0016] 6. The 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 increase process is a process of increasing the on-time ratio with respect to the cycle of the on / off operation of the switching element from a first ratio to a second ratio. The vehicle pinching detection device according to the above 5.

[0017] Even if the above time ratio is the same, when the magnitude of the voltage of the DC voltage source is different, the voltage applied to the motor is different. Therefore, when the applied voltage increase process raises the time ratio from the first time ratio to the second time ratio, the actual applied voltage at the first time ratio and the actual applied voltage at the second time ratio depend on the magnitude of the voltage of the DC voltage source. Accordingly, an appropriate value as the current flowing through the motor when the time ratio is each of the first time ratio and the second time ratio also depends on the magnitude of the voltage of the DC voltage source. Therefore, when performing pinch detection 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.

[0018] 7. The pinch detection process includes a minimum value update process. The minimum value update process is a process of updating the first current value to a value corresponding to the current detected value when the value corresponding to the current detected value is smaller than the first current value. The second current value is a value corresponding to the detected value sampled each time. The vehicle pinch detection device according to 5 or 6 above.

[0019] In the above configuration, the first current value is a value corresponding to the minimum value of the detected value. Therefore, the difference between the first current value and the second current value when a pinch occurs is a value that accurately indicates the increase amount of the current of the motor due to the pinch. Therefore, based on the difference between the first current value and the second current value exceeding the threshold value, a pinch can be detected with high accuracy.

[0020] 8. The first current value and the second current value are values corresponding to each of a pair of detected values sampled at each of a pair of timings separated by a specified period. The specified period is a period during which the motor rotates by a predetermined angle. The vehicle pinch detection device according to 5 or 6 above.

[0021] When converting the torque of the motor into the force that displaces the movable member, the magnitude of the load torque applied to the motor may periodically vary depending on the mechanical characteristics of the power transmission path of the motor and the like. In that case, the current flowing through the motor varies in accordance with the variation of 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 specified period. Therefore, the influence of the periodic variation of the load torque on the difference between the first current value and the second current value can be reduced. Therefore, in the above configuration, based on the difference between the first current value and the second current value exceeding the threshold value, pinching can be detected with high accuracy.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0023] Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 shows the configuration of a seat and a control device in a vehicle. The rear seat 10r shown in FIG. 1 is used for the rear seat of the vehicle. The rear seat 10r includes a seat cushion 12r, a seat back 14r, and a headrest 16r. The headrest 16r is provided at the upper end of the seat back 14r. On the floor 30 of the vehicle, two lower rails 20r extending in the longitudinal direction of the vehicle are provided in parallel. An upper rail 22r that can move relative to the lower rail 20r in the longitudinal direction of the vehicle is mounted on each lower rail 20r. The seat cushion 12r is supported on each upper rail 22r. And the seat cushion 12r can move relative to the lower rail 20r in the longitudinal direction of the vehicle integrally with the upper rail 22r.

[0024] The front seat 10f is used for the front seat of the vehicle. The front seat 10f includes a seat cushion 12f, a seat back 14f, and a headrest 16f. In this specification and the drawings, the reference numerals of the members related to the front seat 10f are given "f" after the number, while the reference numerals of the members related to the rear seat 10r are given "r" after the number. Here, among the members related to the front seat 10f, those whose numerical part of the reference numeral coincides with that of the members related to the rear seat 10r mean that they correspond to the members related to the rear seat 10r. That is, the seat cushion 12f, the seat back 14f, and the headrest 16f respectively correspond to the seat cushion 12r, the seat back 14r, and the headrest 16r.

[0025] The seat cushion 12f can move relative to the lower rail 20f in the longitudinal direction of the vehicle 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 by the power of the motor 42r. The reclining actuator 50r changes the tilt angle of the seat back 14r by the power of the motor 52r. Specifically, the reclining actuator 50r rotates and displaces the upper end side of the seat back 14r about an axis provided on the seat cushion 12r side of the seat back 14r.

[0026] The reclining actuator 50r includes a motor 52r and a drive circuit 54r. The motor 52r is a DC motor. The drive circuit 54r is a drive circuit having two sets of half-bridge circuits. That is, a connection point of a switching element SW1 and a switching element SW2 constituting the first half-bridge circuit is connected to one of the two terminals of the motor 52r. Also, a connection point of a switching element SW3 and a switching element SW4 constituting the second half-bridge circuit is connected to the other. Note that the positive terminal of the battery B is connected to the switching element SW1, SW3 side of the drive circuit 54r, and the switching element SW2, SW4 side is grounded.

[0027] In addition to the motor 42r, the slide actuator 40r includes a drive circuit 44r that drives the motor 42r. The front seat 10f is provided with a slide actuator 40f and a reclining actuator 50f. The slide actuator 40f includes a motor 42f and a drive circuit 44f. Also, the reclining actuator 50f includes a motor 52f and a drive circuit 54f.

[0028] The rear ECU 60r operates the slide actuator 40r and the reclining actuator 50r to control the control amount of the rear seat 10r as the control target. The control amount at this time is the position of the seat cushion 12r and the tilt angle of the seat back 14r. When controlling the control amount, the rear ECU 60r refers to the output signal Sm of the rotation angle sensor 56r. 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.

[0029] In the rear ECU 60r, the CPU 62r, the ROM 64r, the storage device 66r, and the peripheral circuit 68r are communicable with each other via the communication line 69r. Here, the peripheral circuit 68r includes a circuit that generates a clock signal for defining 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 the program stored in the ROM 64r.

[0030] The front ECU 60f operates the slide actuator 40f and the reclining actuator 50f to control the control amount of the front seat 10f as the control target. In the front ECU 60f, the CPU 62f, the ROM 64f, the storage device 66f, and the peripheral circuit 68f are communicable with each other via the communication line 69f.

[0031] The front ECU 60f and the rear ECU 60r 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. The user interface 72 enables the user to perform an input operation for giving an instruction to adjust the control amount of the front seat 10f and the control amount of the rear seat 10r. The instruction here includes an instruction to recline the seat back 14f of the front seat 10f and the seat back 14r of the rear seat 10r forward as shown in FIG. 2. Hereinafter, this instruction is referred to as a folding instruction. Hereinafter, the "processing according to the folding instruction", the "pre-processing of the pinching detection process accompanying the folding process", and the "pinching detection process" will be described in detail in this order.

[0032] (Processing according to the folding instruction) FIG. 3 shows the procedure of the process executed by the front ECU 60f. The process shown in FIG. 3 is realized by the CPU 62f repeatedly executing the program stored in the ROM 64f, for example, at a predetermined cycle. Hereinafter, the step numbers of each process are represented by numbers with "S" added at the beginning.

[0033] In the series of processes shown in FIG. 3, the CPU 62f first determines whether or not the folding flag F1 is "1" (S10). The folding flag F1 indicates that the process according to the folding instruction is being executed when it is "1", and indicates that it is not being executed when it is "0". When the CPU 62f determines that the folding flag F1 is "0" (S10: NO), it determines whether or not a folding instruction has been given by an operation of the user interface 72 (S12). When the CPU 62f determines that a folding instruction has been given (S12: YES), it substitutes "1" into the folding 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 it has detected a pulse signal, which is the output signal Sm of the rotation angle sensor 56f indicating that the rotation angle of the motor 52f has reached a predetermined angle (S18). When the CPU 62f determines that it has detected it (S18: YES), it updates the total rotation speed Ntot1 of the motor 52f (S20). Here, the total rotation speed Ntot1 has a one-to-one correspondence with the tilt angle of the seat back 14f. The total rotation speed Ntot1 is incrementally corrected or decrementally corrected according to the rotation direction of the motor 52f. In the present embodiment, it is assumed that the seat back 14f falls forward as the total rotation speed Ntot1 increases. Therefore, in the process of S20, the CPU 62f incrementally corrects the total rotation speed Ntot1.

[0034] Next, the CPU 62f determines whether or not the total rotation speed Ntot1 has reached a predetermined value Ntot1th (S22). The predetermined value Ntot1th corresponds to the tilt angle of the seat back 14f 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.

[0035] Fig. 4 shows an example where the headrest 16f of the front seat 10f interferes with the headrest 16r of the rear seat 10r. That is, at the time when the folding instruction is given, since the tilt angles of the seatback 14f and the seatback 14r can take various values because the user freely sets them, and the distance between the seat cushion 12f and the seat cushion 12r can also take various values. Therefore, when performing the process 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.

[0036] Returning to Fig. 3, when the CPU 62f determines that the predetermined value Ntot1th has been reached (S22: YES), it notifies the rear ECU 60r to that effect via the in-vehicle network 70 (S24).

[0037] On the other hand, when the CPU 62f determines that the folding flag F1 is "1" (S10: YES), it 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 seatback 14f is in the state shown in Fig. 2. When the CPU 62f determines that it has not reached the target rotation speed Ntot1* (S26: NO), it proceeds to the process of S16. In contrast, when the CPU 62f determines that it has reached (S26: YES), it substitutes "0" into the folding flag F1 (S28). Then the CPU 62f stops the motor 52f (S30).

[0038] Note that when the CPU 62f completes the processes of S24 and S30, and when it makes a negative determination in the processes of S12, S18, and S22, the series of processes shown in Fig. 3 are temporarily terminated.

[0039] Fig. 5 shows the procedure of the process executed by the rear ECU 60r. The process shown in Fig. 5 is realized by the CPU 62r repeatedly executing the program stored in the ROM 64r, for example, at a predetermined cycle.

[0040] In the series of processes shown in FIG. 5, the CPU 62r first determines whether the folding flag F2 is "1" (S31). The folding flag F2 indicates that the process according to the folding instruction is being executed when it is "1", and indicates that it is not being executed when it is "0". When the CPU 62r determines that the folding flag F2 is "0" (S31: NO), it determines whether a folding instruction has been given by an operation of the user interface 72 (S32). When the CPU 62r determines that a folding instruction has been given (S32: YES), it substitutes "1" into the folding flag F2 (S34). Then, the CPU 62r determines whether the notification by the process of S24 has been made (S36). When the CPU 62r determines that it has not been made (S36: NO), it determines whether the total rotation speed Ntot2 of the motor 52r is equal to or less than a predetermined value Ntot2th (S38). The total rotation speed Ntot2 has a one-to-one correspondence with the inclination angle of the seat back 14r. The predetermined value Ntot2th is set to the maximum value of the total rotation speed 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.

[0041] When the CPU 62r determines that it is equal to or less than the predetermined value Ntot2th (S38: YES), it substitutes the first time ratio DL into the time ratio D (S40). The time ratio D indicates the ratio of the on-time to the PWM period for turning on and off the switching element SW2 or the switching element SW4.

[0042] Then, the CPU 62r drives the drive circuit 54r according to the time ratio D (S42). That is, the CPU 62r controls the rotation direction of the motor 52r by selecting whether to turn on the switching element SW1 and the switching element SW4 or to turn on the switching element SW3 and the switching element SW2. Further, the CPU 62r turns on and off the switching element SW2 or the switching element SW4 at the time ratio D.

[0043] The CPU 62r determines whether it has detected 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 (S46). When the CPU 62r determines that it has detected the signal (S46: YES), it updates the total rotation speed Ntot2 of the motor 52r (S48). Here, the total rotation speed Ntot2 is incrementally or decrementally corrected according to the rotation direction of the motor 52r. In this embodiment, it is assumed that the larger the total rotation speed Ntot2, the more the seat back 14r tilts forward. Therefore, in the process of S48, the CPU 62r incrementally corrects the total rotation speed Ntot2.

[0044] On the other hand, when the CPU 62r determines that the notification by the process of S24 has been made (S36: YES), it substitutes the second time ratio DH for the time ratio D (S50). The second time ratio DH is set to a value larger than the first time ratio DL. In this embodiment, specifically, the second time ratio DH is set to "100". Then the CPU 62r proceeds to the process of S42. As a result, the drive circuit 54r will be operated according to the second time ratio DH.

[0045] Note that in the process of S16 in FIG. 3, the motor 52f is driven by operating the drive circuit 54f with the time ratio D as the second time ratio DH. Also, when the CPU 62r determines that the folding flag F2 is "1" (S31: YES), it determines whether 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. 2. When the CPU 62r determines that it has not reached the target rotation speed Ntot2* (S52: NO), it proceeds to the process of S36. In contrast, when the CPU 62r determines that it has reached the target rotation speed Ntot2* (S52: YES), it substitutes "0" for the folding flag F2 (S54). When the CPU 62r completes the process of S54 or makes a negative determination in the process of S38, it stops the motor 52r (S56).

[0046] Note that when the CPU 62r completes the processes of S48 and S56, and when a negative determination is made in the processes of S32 and S46, the series of processes shown in FIG. 5 are temporarily terminated. (Preprocessing of the pinching detection process associated with the tatami folding process) FIG. 6 shows the procedure of the above preprocessing. The process shown in FIG. 6 is realized by the CPU 62r repeatedly executing a program stored in the ROM 64r, for example, at a predetermined cycle.

[0047] 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 performing a low-pass filter process on the detected value i (S62). Then, the CPU 62r substitutes the value obtained by multiplying the post-filter current ifil0 by "100 / D" into the determination current value ifil1 (S64). "100 / D" is a coefficient for reducing the difference in the magnitudes of the detected value i and the post-filter current ifil0 due to the difference in the time ratio D. That is, when the time ratio D is the second time ratio DH compared to when it is the first time ratio DL, the applied voltage to the motor 52r becomes larger. In other words, the effective value of the voltage applied to the motor 52r becomes larger. Therefore, when the time ratio D is the second time ratio DH, the magnitudes of the detected value i and the post-filter current ifil0 are larger than when it is the first time ratio DL. On the other hand, the coefficient "100 / D" becomes smaller when the time ratio D is the second time ratio DH compared to when it is the first time ratio DL. Therefore, the determination current value ifil1 does not change significantly between when the time ratio D is the first time ratio DL and when it is the second time ratio DH.

[0048] Next, the CPU 62r determines whether the timing is when the time ratio D switches from the first time ratio DL to the second time ratio DH (S66). And when the CPU 62r determines that it is the switched timing (S66: YES), it substitutes the determination current value ifil1 calculated in the process of S64 immediately before the same timing into the reference value ifillast (S68).

[0049] On the other hand, when the CPU 62r determines that it is not the switched timing (S66: NO), it determines whether the determination current value ifil1 is smaller than the reference value ifillast (S70). And when the CPU 62r determines that it is smaller (S70: YES), it substitutes the value obtained by multiplying the post-filter current ifil0 by "100 / DL" into the determination current value ifil1 (S72).

[0050] Note that when the CPU 62r completes the processes of S68 and S72, and when it makes a negative determination in the process of S70, it temporarily ends the series of processes shown in FIG. 6. (Pinch detection process) FIG. 7 shows the procedure of the pinch detection process. The process shown in FIG. 7 is realized by the CPU 62r repeatedly executing the program stored in the ROM 64r at a predetermined period, for example.

[0051] In the series of processes shown in FIG. 7, the CPU 62r first substitutes the smaller value between the minimum value ifilmin and the determination current value ifil1 into the minimum value ifilmin (S80). Then, the CPU 62r determines whether the value obtained by subtracting the minimum value ifilmin from the determination current value ifil1 is greater than the threshold value Δth1 (S82). This process is to determine whether a pinch has occurred due to the displacement of the seat back 14r. That is, when a pinch occurs, the force required to displace the seat back 14r increases, so the rotational speed of the motor 52r decreases. As a result, the induced voltage of the motor 52r decreases, and thus the magnitude of the current flowing through the motor 52r increases.

[0052] When the CPU 62r determines that it is greater than the threshold value Δth1 (S82: YES), it determines that a pinch has been detected (S90). And the CPU 62r forcibly stops the motor 52r (S92).

[0053] On the other hand, when the CPU 62r determines that it is equal to or less than the threshold value Δth1 (S82: NO), after the start of the convolution process, it determines whether the motor 52r has rotated by ΔNtot2 or more pulsation cycles (S84). The pulsation cycle ΔNtot2 is the cycle of fluctuations due to mechanical factors of the magnitude of the force required to displace the seat back 14r. The pulsation cycle ΔNtot2 is pre - adapted as a value specific to the mechanism for displacing the seat back 14r, such as the number of teeth of the gear.

[0054] Then, when the CPU 62r determines that it has rotated by ΔNtot2 or more pulsation cycles (S84: YES), it substitutes the determination current value ifil1 sampled ΔNtot2 cycles before into the pre - cycle current value ifilr (S86). Then the CPU 62r determines whether 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 for determining whether pinching has occurred due to the displacement of the seat back 14r.

[0055] When the CPU 62r determines that it is greater than the threshold value Δth2 (S88: YES), it proceeds to the process of S90. Note that when the CPU 62r completes the process of S92 and when it makes a negative determination in the processes of S84 and S88, the series of processes shown in FIG. 7 is temporarily terminated.

[0056] Here, the operations and effects of the present embodiment will be described. FIG. 8 illustrates the transition of the determination current value ifil1. As shown in FIG. 8, when the time ratio D switches from the first time ratio DL to the second time ratio DH at time t1, the CPU 62r substitutes the determination current value ifil1 immediately before that into the reference value ifillast.

[0057] Here, when switching from the first time ratio DL to the second time ratio DH, the current ifil0 after filtering increases. However, even if the effective value of the voltage increases, due to the inductance of the coil of the motor 52r or the like, there is a response delay until the current flowing through the motor 52r reaches a steady value. Therefore, when calculating the determination current value ifil1 using the coefficient "100 / DH", due to the decrease of the coefficient "100 / D" at time t1, the determination current value ifil1 becomes smaller than the reference value ifillast. Thus, the CPU62r substitutes the value obtained by multiplying the current ifil0 after filtering by the coefficient "100 / DL" into the determination current value ifil1 while the determination current value ifil1 calculated using the coefficient "100 / DH" is smaller than the reference value ifillast. Then, the CPU62r 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" becomes equal to or greater than the reference value ifillast.

[0058] FIG. 8 shows that at time t3, the current flowing through the motor 52r reaches a steady value. Incidentally, before time t1, when the time ratio D is the first time ratio DL, the current flowing through the motor 52r has reached a steady value. As shown in FIG. 8, in this embodiment, the difference between the steady value of the determination current value ifil1 at the first time ratio DL and the steady value of the determination current value ifil1 at the second time ratio DH is sufficiently small.

[0059] On the other hand, as shown in FIG. 8, for the post-filter current ifil0, the steady-state value IH at the second time ratio DH becomes significantly larger than the steady-state value IL at the first time ratio DL. Therefore, for example, when two values sampled at different timings in the process of S82 are used as the post-filter current ifil0 instead of the determination current value ifil1, it is more likely to be positively determined after setting the second time ratio DH. Therefore, for example, when the threshold value Δth1 is set to an appropriate value for the first time ratio DL, there is a risk of misjudging that clamping has occurred even though clamping actually has not occurred at the second time ratio DH. Also, when the threshold value Δth1 is set to an appropriate value for the second time ratio DH, there is a risk of misjudging that clamping has not occurred even though clamping actually has occurred at the first time ratio DL.

[0060] This is because, although the upper limit value of the current magnitude that should not be determined to have clamping occurs changes according to the magnitude of the time ratio D, when using the post-filter current ifil0, the same upper limit value is fixed. That is, if it is appropriate to set the upper limit value as the value obtained by adding the threshold value Δth1 to the steady-state value, the upper limit value at the first time ratio DL should be a value that is a predetermined amount larger than the steady-state value IL, while the upper limit value at the second time ratio DH should be a value that is a predetermined amount larger than the steady-state value IH.

[0061] In contrast, according to the present embodiment, by using the determination current value ifil1, in the process of S82, the upper limit value of the post-filter current ifil0 that is not determined to have clamping is as follows. That is, in the first time ratio DL, considering the minimum value ifilmin to be about the steady value IL, it becomes about "IL+(DL / 100)Δth1". On the other hand, in the second time ratio DH, considering the minimum value ifilmin to be about the steady value IL, it becomes about "(100 / DL)·IL+Δth1". In the present embodiment, "IL>Δth1". Therefore, by switching the time ratio D to the second time ratio DH, the upper limit value increases. Incidentally, this discussion also holds true for the detected value i. That is, in the present embodiment, the upper limit value of the detected value i that is not determined to have clamping is larger at the second time ratio DH than at the first time ratio DL.

[0062] Therefore, according to the present embodiment, even if the time ratio D is changed during the displacement of the seat back 14r, clamping can be detected with high accuracy. According to the present embodiment described above, the following operations and effects can be obtained.

[0063] (1) Based on the degree to which the determination current value ifil1 exceeds the minimum value ifilmin and the absolute value of the difference between the determination current value ifil1 and the pre-cycle current value ifilr, the presence or absence of clamping is determined. As a result, the upper limit values of the detected value i and the post-filter current ifil0 that are not determined to be clamped can be adjusted to appropriate values according to various factors that change the magnitude of the current other than the time ratio D. That is, for example, it can be adjusted to appropriate values according to the aging change of the rear seat 10r, the temperature of the rear seat 10r, the temperature of the current flow path of the motor 52r, and the terminal voltage of the battery B. Therefore, compared with the case where the upper limit value is fixed for each time ratio D, clamping detection can be calculated with higher accuracy.

[0064] That is, the force required to displace the seat back 14r varies depending on the aging of the rear seat 10r, temperature, and the like. Therefore, even when the applied voltage to the motor 52r is the same, the rotational speed of the motor 52r when displacing the seat back 14r varies depending on the aging of the rear seat 10r, temperature, and the like. Also, 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 when the applied voltage 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 flow path and the like. Further, when the terminal voltage of the battery B fluctuates, the rotational speed of the motor 52r fluctuates even when the time ratio D is the same. Thus, the rotational speed of the motor 52r when no pinching occurs varies depending on the various factors described above. Therefore, the current of the motor 52r when no pinching occurs varies depending on the various factors described above. For this reason, if the upper limit value for not detecting pinching is set as a fixed value for each value of the time ratio D, it tends to be difficult to improve the detection accuracy of pinching.

[0065] (2) In the process of S88, the CPU 62r determines the presence or absence of pinching according to whether the absolute value of the value obtained by subtracting the periodic previous current value ifilr from the determination current value ifil1 is greater than the threshold value Δth2. Thereby, it is possible to determine the presence or absence of pinching while suppressing the influence of the periodic variation of the load torque applied to the motor 52r when displacing the seat back 14r.

[0066] (3) The determination current value is defined such that the steady value of the determination current value ifil1 at the second time ratio DH is slightly smaller than the steady value of the determination current value ifil1 at the first time ratio DL. Thereby, it is possible to suppress loosening of the criterion for detecting pinching after the change of the time ratio D.

[0067] When the determination current value ifil1 calculated using the coefficient "100 / DH" is less than the reference value ifillast after the change in the time ratio D, the value obtained by multiplying the filtered current ifil0 by the coefficient "100 / DL" is set as the determination current value ifil1. Thereby, it is possible to suppress the minimum value ifilmin from being updated to an inappropriate value. Also, compared with the case where the clamping detection is masked over a predetermined period after the change in the time ratio D, the clamping can be detected more quickly.

[0068] <Corresponding relationship> The correspondence between the matters in the above embodiment and the matters described in the column of "Means for Solving the Problems" is as follows. Below, the correspondence is shown for each number of the solution means described in the column of "Means for Solving the Problems". [1] The vehicle pinching detection device corresponds to the rear ECU 60r. The movable part 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 pinching 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 the value obtained by adding the threshold value Δth1 to the minimum value ifilmin, and the 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] The replacement process corresponds to the processes of S66 to S72. The predetermined period corresponds to the period from time t1 to t2 in FIG. 8. [5] The first current value corresponds to either the minimum value ifilmin in the process of S82 or one of the determination current value ifil1 and the pre-cycle current value ifilr in the process of S88. The second current value corresponds to either the determination current value ifil1 in the process of S82 or one of the determination current value ifil1 and the pre-cycle current value ifilr in the process of S88. The threshold value corresponds to the threshold value Δth1 in the process of S82 and the threshold value Δth2 in the process of S88. [6] The switching element corresponds 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 specified period corresponds to the pulsation period ΔNtot2.

[0069] <Other Embodiments> Note that this embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0070] "Regarding the Determination Current Value" · In the above embodiment, the value obtained by multiplying the post-filter current ifil0 by "100 / D" is used as the determination current value ifil1, but it is not limited to this. For example, the value obtained by multiplying the detected value i by "100 / D" may be used as the determination current value ifil1.

[0071] · The coefficient for making the determination current value ifil1 smaller relative to the magnitude of the detected value i when the applied voltage is large than when it is small is not limited to "100 / D". For example, a constant K other than "100" may be used, and it may be set as "K / D". Here, as the constant K, the first time ratio DL may be used.

[0072] · It is not essential to set the steady-state value of the determination current value ifil1 in the second time ratio DH to be larger than the steady-state value of the determination current value ifil1 in the first time ratio DL. · The determination current value ifil1 is not limited to the value obtained by multiplying the detected value i or the post-filter current ifil0 by a coefficient. For example, the determination current value ifil1 may be calculated by map operation by the CPU62r using map data. Here, as the map data, data having the detected value i or the post-filter 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.

[0073] · The value of the variable indicating the applied voltage used in calculating the determination current value ifil1 is not limited to the time ratio D. For example, when a brushless motor is used as the motor and the applied voltage has a sine wave shape as described in the column "Regarding the Motor" below, the amplitude value of the applied voltage may be adopted.

[0074] "Regarding the Minimum Value Update Process" · The minimum value ifilmin is not limited to the minimum value of the determination current value ifil1 from the start of driving the motor 52r. For example, when the load changes when displacing the seat back 14r according to the position of the seat back 14r, the minimum value ifilmin may be updated for each section where the load is substantially constant.

[0075] "Regarding the pinching detection process" · It is not essential to set the threshold values Δth1 and Δth2 as fixed values in the processes of S82 and S88. For example, when one of the pair of determination current values ifil1 that constitutes the comparison target with the threshold values Δth1 and Δth2 is the value at the first time ratio DL and the other is the value at the second time ratio DH, they may be made smaller. This can be simply achieved by correcting the threshold values Δth1 and Δth2 to the values multiplied by "DL / 100".

[0076] · For example, in the process of S82, instead of the determination current value ifil1 and its minimum value, the filtered current ifil0 and its minimum value may be used. In that case, the threshold value Δth1 may be increased triggered by the increase in the time ratio D. Here, the upper limit value of the filtered current ifil0 without pinching detection is the value obtained by adding the threshold value Δth1 to the minimum value of the filtered current ifil0. Therefore, due to the increase in the time ratio D, the upper limit value will be changed to a larger value. Incidentally, as described in the section "Regarding the minimum value update process", when determining the minimum value ifilmin for each interval, the process of increasing the threshold value Δth1 is changed as follows. That is, the threshold value Δth1 is increased only when the applied voltage has increased after the sampling of 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 value Δth1. For example, the detected value i and its minimum value may be used.

[0077] Also, for example, in the process of S88, the threshold value Δth2 may be increased only when the applied voltage has been increased within one pulse period from the execution timing of the same process. "Regarding the 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. 6. In other words, the timing when a predetermined period has elapsed after increasing the applied voltage is not limited to the timing illustrated in FIG. 6. For example, it may be the timing when the current value of ifil0 after filtering is lower than the previous value.

[0078] · It is not essential to execute the replacement process. For example, a masking period during which the sandwiching detection process is not executed may be provided for a predetermined period after increasing the applied voltage. "Regarding the countermeasure process for sandwiching" · The process for dealing with the situation where sandwiching is detected is not limited to the process of S92. For example, it may be a process of reversing the motor 52r. Note that in order to reverse the motor 52r, since it is necessary to set the rotational speed of the motor 52r to zero once, this can be regarded as including the process of stopping the motor 52r.

[0079] · It is not essential that the process for dealing with the situation where sandwiching is detected includes the process of stopping the motor 52r. For example, it may be a process of operating the speaker to issue an alarm while controlling the torque of the motor 52r to zero.

[0080] "Regarding the applied voltage increase process" · The purpose of the process of increasing the applied voltage to the motor 52r is not limited to the purpose of avoiding interference between the headrest 16f of the front seat 10f and the headrest 16r of the rear seat 10r. For example, during the period required for the user to perceive that the seat backs 14f and 14r start to displace, the applied voltage may be decreased, and then the applied voltage may be increased.

[0081] "Regarding the movable member" ·The movable member that is the target of pinch detection and is a member constituting the seat is not limited to the seat backs 14f and 14r. For example, the seat cushions 12f and 12r may also be used. That is, pinch may be detected when the upper rails 22f and 22r are relatively displaced with respect to the lower rails 20f and 20r.

[0082] ·The movable member that is the target of pinch detection is not limited to the members constituting the seat. For example, it may be an opening / closing body that opens and closes an opening of a vehicle, such as the slide door 84 shown in FIG. 9. The slide door 84 shown in FIG. 9 opens and closes the opening 82 of the vehicle 80.

[0083] "Regarding the pinch detection device" ·The pinch detection device is not limited to one that includes a CPU and a ROM and executes software processing. For example, at least a part of what was software-processed in the above embodiment may be provided with a dedicated hardware circuit such as an ASIC that performs hardware processing. That is, the pinch detection device may have any of the following configurations (a) to (c). (a) It includes a processing device that executes all of the above processing according to a program and a program storage device such as a ROM that stores the program. (b) It includes a processing device and a program storage device that execute a part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (c) It includes a dedicated hardware circuit that executes all of the above processing. Here, there may be a plurality of software execution devices including a processing device and a program storage device, and dedicated hardware circuits.

[0084] "Regarding the drive circuit of the motor" · The drive circuit of the motor 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 may be energized in a 120° conduction mode. And if the switching element is turned on for a period of 120°, the duty ratio D may be set to 100%. In that case, by determining the PWM period during the same period and performing on / off operations on the switching element, the duty ratio D can be set to a value less than "100%". Note that the voltage applied to the motor is not limited to a rectangular wave voltage. For example, the applied voltage to the motor terminals may be changed to a sine wave shape by changing the duty ratio of the inverter to a sine wave shape. In that case, increasing the applied voltage means increasing the amplitude of the sine wave-shaped voltage.

[0085] "Others" · In FIG. 1, the front ECU 60f and the rear ECU 60r may be integrated. · In FIG. 1, for example, three seats may be arranged side by side in the vehicle. In that case, the rear seat 10r in FIG. 1 may be the rearmost seat or the middle seat.

Description of Reference Numerals

[0086] 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

1. Applied to a vehicle comprising a movable member and a motor for displacing the movable member, the movable member is either one of a movable part of a seat and an opening / closing body for opening and closing an opening of the vehicle, executes instruction acquisition processing, displacement processing, and pinching detection processing, the instruction acquisition processing is processing for acquiring an instruction to displace the movable member, the displacement processing is processing for driving the motor to displace the movable member when the instruction is acquired by the instruction acquisition processing and includes applied voltage increase processing, the applied voltage increase processing is processing for increasing the applied voltage to the terminals of the motor when the movable member is being displaced by driving the motor, the pinching detection processing is processing for detecting that pinching has occurred due to the displacement of the movable member based on the magnitude of the detected value of the current flowing through the motor and includes processing for making the upper limit value of the detected value that is not determined as the pinching larger after the increase in the applied voltage than before the increase, the pinching detection processing includes determination current value calculation processing and determination processing, the determination current value calculation processing is processing for calculating a determination current value, which is a current value used for determination of pinching, based on the detected value, the determination current value is set to be a smaller value relative to the magnitude of the detected value when the applied voltage is large than when it is small, the determination processing is processing for determining whether pinching has occurred based on a comparison of the magnitudes of the determination current value and a determination value, and is a vehicle pinching detection device.

2. the determination current value calculation processing includes substitution processing, the substitution processing is processing for substituting, during a predetermined period after increasing the applied voltage, each determination current value used for determination of pinching each time with a value corresponding to the applied voltage before the increase, as claimed in claim 1, for the vehicle pinching detection device.

3. the predetermined period is a period during which the determination current value calculated based on the increased applied voltage is lower than the determination current value before increasing the applied voltage, as claimed in claim 2, for the vehicle pinching detection device.

4. the determination processing is processing for determining that pinching has occurred when the difference between a first current value and a second current value corresponding to each of a pair of detected values sampled at different timings exceeds a threshold value. The first current value and the second current value are determination current values calculated based on the detection values at different timings from each other. The vehicle pinching detection device according to any one of claims 1 to 3, wherein a value obtained by adding the threshold value to the smaller one of the first current value and the second current value is the determination value.

5. 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. The applied voltage increase process is a process of increasing a duty ratio of an on-time with respect to a cycle of an on / off operation of the switching element from a first duty ratio to a second duty ratio. The vehicle pinching detection device according to claim 4.

6. The pinching detection process includes a minimum value update process. The minimum value update process is a process of updating the first current value to a value corresponding to the current detection value when a value corresponding to the current detection value is smaller than the first current value. The second current value is a value corresponding to the detection value sampled each time. The vehicle pinching detection device according to claim 4 or 5.

7. The first current value and the second current value are values corresponding to each of a pair of detection values sampled at each of a pair of timings separated by a specified period. The specified period is a period during which the motor rotates by a predetermined angle. The vehicle pinching detection device according to claim 4 or 5.

Images