Actuator Control Device

Abstract

To provide an actuator control device capable of improving responsiveness.SOLUTION: A control device 60 includes a drive control unit 78 and a controlled variable calculating unit 76. The drive control unit 78 controls driving of a motor 40 so that a detent roller 26 moves to a target trough. The controlled variable calculating unit 76 calculates a current-carrying time and a current-carrying amount of backlash elimination control for returning the motor 40 in a reverse direction within a range of a play between the motor 40 and an output shaft 15 after the detent roller 26 reaches the target trough. The controlled variable calculating unit 76 estimates an idle running amount of the motor 40 within the range of the play between the motor 40 and the output shaft 15 after the detent roller 26 reaches the target trough with the usage of an electric current value I after stopping power feeding to the motor 40. The controlled variable calculating unit 76 calculates a backlash elimination time Xg and a backlash elimination duty Dg in backlash elimination control as controlled variables on the basis of the estimated idle running amount.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an actuator control device. [Background technology]

[0002] Conventionally, there is known a shift range control device that switches the shift range by controlling the drive of a motor. For example, in Patent Document 1, after stopping the motor at a target position, return control is performed to return the rotational position of the motor within a play range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6862906 Summary of the Invention [Problem to be solved by the invention]

[0004] In the return control of Patent Document 1, the motor is driven in steps by the minimum driveable width according to the resolution. This type of control requires a highly accurate and noise-resistant sensor, and if the control is incorrect and the motor is driven beyond the play range, there is a risk that the detent roller will deviate from the valley position.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an actuator control device that can improve responsiveness. [Means for solving the problem]

[0006] The actuator control device of the present invention controls switching of the detent mechanism in a drive system (1) including an actuator (10) having a drive source (40) and a detent mechanism (20) having a detent member (21) and an engagement member (26) by driving the actuator to move the engagement member. The detent member is formed with a plurality of valleys (211, 212) and peaks (215) separating the valleys. The engagement member is movable between the valleys when the output shaft (15) is driven by the actuator.

[0007] The actuator control device includes a drive control unit (78) and a control amount calculation unit (76). The drive control unit controls the drive of the drive source so that the engaging member moves to the target valley. The control amount calculation unit calculates the energization time and energization amount of return control that returns the drive source in the reverse direction within the range of play between the drive source and the output shaft after the engaging member reaches the target valley.

[0008] The control amount calculation unit estimates the amount of free running of the drive source within the range of play between the drive source and the output shaft after the engaging member reaches the target valley using the current value after power supply to the drive source is stopped, and calculates the current supply time and current amount for the return control based on the estimated amount of free running, thereby improving responsiveness. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram showing a parking lock system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing a control device according to the first embodiment. [Figure 3] 10A is an explanatory diagram illustrating a switching process, and FIG. 10B is an explanatory diagram illustrating a return control. [Figure 4] 4 is a flowchart illustrating a switching process according to the first embodiment. [Figure 5] 4 is a flowchart illustrating a switching process according to the first embodiment. [Figure 6] 4 is a time chart illustrating a switching process according to the first embodiment. [Figure 7] 10 is a flowchart illustrating a switching process according to the second embodiment. [Figure 8] 10 is a time chart illustrating a switching process according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) An actuator control device according to the present invention will now be described with reference to the drawings. In the following, substantially identical components in multiple embodiments will be denoted by the same reference numerals, and descriptions thereof will be omitted. A first embodiment is shown in FIGS. 1 to 6.

[0011] As shown in Fig. 1, an electric actuator 10 is applied to a parking lock system 1. The park lock system 1 includes the electric actuator 10, a detent mechanism 20, and a parking lock mechanism 30. The electric actuator 10 is a rotary type and includes a motor 40, such as a brushed DC motor, a reduction gear mechanism, and the like. The electric actuator 10 drives the detent mechanism 20 by rotating an output shaft 15.

[0012] The detent mechanism 20 has a detent plate 21, a detent spring 25, etc., and transmits the rotational driving force output from the electric actuator 10 to the parking lock mechanism 30.

[0013] The detent plate 21 is fixed to the output shaft 15 and driven by the electric actuator 10. On the side of the detent spring 25 of the detent plate 21, two valleys 211, 212 and a peak 215 separating the valleys 211, 212 are provided.

[0014] The detent spring 25, which is a biasing member, is an elastically deformable plate-like member, and has a detent roller 26 at its tip. The detent spring 25 biases the detent roller 26 toward the rotation center of the detent plate 21.

[0015] When a rotational force greater than or equal to a predetermined value is applied to the detent plate 21, the detent spring 25 elastically deforms, and the detent roller 26 moves between the valleys 211 and 212. When the detent roller 26 fits into either of the valleys 211 or 212, the oscillation of the detent plate 21 is restricted, and the state of the parking lock mechanism 30 is fixed.

[0016] The parking lock mechanism 30 has a parking rod 31, a cone 32, a parking lever 33, a shaft 34, and a parking gear 35. The parking rod 31 is formed in a generally L-shape, and one end 311 is fixed to the detent plate 21. The other end 312 of the parking rod 31 is provided with a cone 32. The cone 32 is formed so that its diameter decreases toward the other end 312. When the detent plate 21 rotates in a direction in which the detent roller 26 fits into the valley 211 corresponding to the P range, the cone 32 moves in the direction of arrow P.

[0017] The parking lever 33 abuts against the conical surface of the cone 32 and is provided so as to be able to swing around a shaft 34. A protrusion 331 that can mesh with the parking gear 35 is provided on the parking lever 33 on the parking gear 35 side. When the cone 32 moves in the direction of arrow P due to rotation of the detent plate 21, the parking lever 33 is pushed up and the protrusion 331 meshes with the parking gear 35. On the other hand, when the cone 32 moves in the direction not indicated by arrow P, the meshing between the protrusion 331 and the parking gear 35 is released.

[0018] The parking gear 35 is connected to a drive shaft (not shown) and is provided so as to be able to mesh with a protrusion 331 of the parking lever 33. When the parking gear 35 meshes with the protrusion 331, rotation of the drive shaft is restricted. When the shift range is a range other than P, i.e., a not P range, the parking gear 35 is not locked by the parking lever 33, and rotation of the drive shaft is not prevented by the parking lock mechanism 30. Furthermore, when the shift range is P range, the parking gear 35 is locked by the parking lever 33, and rotation of the drive shaft is restricted.

[0019] Hereinafter, the valley portion 211 into which the detent roller 26 fits when in the P range will be referred to as the "P valley," the valley portion 212 into which the detent roller 26 fits when in the not P range will be referred to as the "not P valley," and the bottom of the valley portions 211 and 212 will be referred to as the "bottom."

[0020] As shown in Fig. 2, the control device 60 includes a drive circuit 61 and a control unit 70. The drive circuit 61 includes drive elements (not shown). The control unit 70 is mainly configured with a microcomputer or the like, and includes a CPU, ROM, RAM, I / O, and bus lines connecting these components (all not shown). Each process in the control unit 50 may be software processing in which the CPU executes a program stored in advance in a physical memory device (i.e., a readable non-transitory tangible recording medium) such as a ROM, or may be hardware processing using a dedicated electronic circuit.

[0021] The control unit 70 acquires the requested shift range, sets a target range, and controls the driving of the electric actuator 10 so that the detent roller 26 is positioned at the valleys 211, 212 corresponding to the target range. The control unit 70 has, as functional blocks, a signal acquisition unit 71, a rotation calculation unit 72, a temperature calculation unit 74, a position determination unit 75, a control amount calculation unit 76, and a drive control unit 78. The signal acquisition unit 71 acquires sensor signals including a position detection signal from the output shaft sensor 55, a current signal from the current sensor 56, and a temperature signal from the temperature sensor 57. The signal acquisition unit 71 also acquires a signal related to the requested shift range from a higher-level ECU (not shown) or the like.

[0022] The rotation calculation unit 72 calculates the output shaft angle θs and the output shaft angular velocity ω based on the detection values ​​of the output shaft sensor 55. The output shaft sensor 55 is not limited to a sensor that directly detects the rotation of the output shaft 15, but may instead detect the rotation of a shaft connected to the output shaft 15 or a gear or the like that constitutes a reduction mechanism provided between the motor shaft and the output shaft, and convert the rotation into an appropriate gear ratio or the like.

[0023] A current calculation unit 73 calculates a current value I of the motor current that is the current that is passed through the motor 40 based on the detection value of the current sensor 56. A temperature calculation unit 74 calculates an actuator temperature p based on the detection value of the temperature sensor 57. A position determination unit 75 determines the position of the detent roller 26 in the detent mechanism 20.

[0024] The control amount calculation unit 76 estimates the amount of free running of the motor 40 after the detent roller 26 reaches the target valley, and calculates the backlash elimination time Xg and backlash elimination duty Dg in the backlash elimination control as control amounts based on the amount of free running. Details of the backlash elimination control will be described later. The drive control unit 78 controls the drive of the motor 40 by controlling the on / off operation of the drive element of the drive circuit 61.

[0025] 3(a) and 3(b) schematically show the play between the motor 40 and the output shaft 15, with the left-right direction on the paper regarded as the direction of rotation, and show how the detent roller 26 moves between the valleys 211 and 212. In reality, the detent roller 26 moves between the valleys 211 and 212 as the detent plate 21, which rotates integrally with the output shaft 15, rotates. In FIGS. 3(a) and 3(b), the operation of the motor, etc. is indicated by dashed arrows.

[0026] In this embodiment, a speed reduction mechanism is provided between the motor 40 and the output shaft 15, and the total play between the motor shaft and the output shaft is defined as the backlash width Gw. As shown in FIG. 3(a), at time x10 before the motor 40 is driven, the motor shaft is positioned somewhere within the backlash width Gw. The motor 40 is driven in the direction not P, and when the backlash in the drive direction is eliminated at time x11, the output shaft 15 is driven, and the detent roller 26 is driven toward the apex of the ridge 215. Hereinafter, eliminating the backlash will be referred to as "backlash elimination" where appropriate.

[0027] When the detent roller 26 overcomes the peak 215, the load torque reverses, and the output shaft 15 moves ahead due to the spring force of the detent spring 25, causing the detent roller 26 to move toward the valley 212. At time x13, the detent roller 26 reaches the bottom of the valley 212, and the motor shaft rotates within the backlash width Gw until time x15, when the motor 40 stops. Hereinafter, the amount of movement within the backlash after the detent roller 26 reaches the bottom of the target valley is referred to as the amount of movement within the backlash θg.

[0028] If the switching process is terminated while the state is as it is at time x15, the next time the range is switched from the not-P range to the P range, it will take longer to switch by the amount of backlash movement θg compared to when driving is started from a state where the play is eliminated in the P range direction. Therefore, in this embodiment, from time x15 when the stop control ends, backlash elimination control is performed in which the motor 40 is driven in the direction opposite to that at the time of switching according to the amount of backlash movement θg, thereby eliminating a certain amount of backlash within a range in which the detent roller 26 does not deviate from the valley (see FIG. 3(b)). Note that FIGS. 3(a) and 3(b) are shown corresponding to the times in FIG. 6.

[0029] The switching process of this embodiment will be described based on the flowcharts of Figures 4 and 5. The process of Figure 4 and the like is executed at a predetermined cycle by the control unit 70. Hereinafter, the "step" such as step S101 will be omitted and simply referred to as the symbol "S".

[0030] In S101, the control unit 70 determines whether the driving mode is the standby mode. If it is determined that the driving mode is not the standby mode (S101: NO), the process proceeds to S105. If it is determined that the driving mode is the standby mode (S101: YES), the process proceeds to S102.

[0031] In S102, the control unit 70 determines whether the target range has been switched. If it is determined that the target range has not been switched (S102: NO), the standby mode continues. If it is determined that the target range has been switched (S102: YES), the process proceeds to S103. In S103, the control unit 70 sets the drive mode to the switching mode. In S104, the drive control unit 78 turns on the power supply to the motor 40 to drive the motor 40. At this time, the duty is controlled to be the drive duty Dd.

[0032] In S105, the control unit 70 determines whether the drive mode is the switching mode. If it is determined that the drive mode is not the switching mode (S105: NO), the process proceeds to S109. If it is determined that the drive mode is the switching mode (S105: YES), the process proceeds to S106.

[0033] In S106, the position determination unit 75 determines whether the valley position determination flag Fvj is on. The valley position determination flag Fvj is turned on when the detent roller 26 reaches the bottom of the target valley based on the detection value of the output shaft sensor 55 and the arrival determination time Xj has elapsed. The time elapsed since the detection value of the output shaft sensor 55 reached the target value is measured by a valley position determination counter. If it is determined that the valley position determination flag Fvj is off (S106: NO), the motor 40 continues to be driven at the duty Dd. If it is determined that the valley position determination flag Fvj is on (S106: YES), the process proceeds to S107.

[0034] In S107, the control unit 70 sets the drive mode to the stop mode. In S108, the drive control unit 78 turns off the power supply to the motor 40. In the stop mode, a braking force is generated by circulating back electromotive force. Here, "power supply off" means stopping the power supply from the battery (not shown) to the motor 40.

[0035] 5, if it is determined that the drive mode is not the switching mode (S105: NO), the control unit 70 proceeds to S109, where it determines whether the drive mode is the stop mode. If it is determined that the drive mode is not the stop mode (S109: NO), the control unit 70 proceeds to S115. If it is determined that the drive mode is the stop mode (S109: YES), the control unit 70 proceeds to S110.

[0036] In S110, the control unit 70 determines whether the stop determination time Xoff has elapsed since the transition to the stop mode. If it is determined that the stop determination time Xoff has elapsed (S110: YES), the process proceeds to S112. If it is determined that the stop determination time Xoff has not elapsed (S110: NO), the control unit 70 increments a stop control counter that measures the elapsed time since the transition to the stop mode, and then proceeds to S111.

[0037] In S111, the control amount calculation unit 76 calculates the idle running amount θoff during the stop control (Equation (1-1)). In the equation, R is the circuit resistance, Ke is the torque constant, and Δx is the processing period. (i) is the current value, (i-1) means the previous value.

[0038] θoff (i) =θoff (i-1) +(I (i) ×R / Ke)×Δx (1-1)

[0039] In S112, which is performed when it is determined that the stop determination time Xoff has elapsed (S110: YES), the control unit 70 sets the drive mode to the backlash reduction mode and resets the stop control counter.

[0040] In S113, the control amount calculation unit 76 calculates the backlash-eliminating time Xg (equation (2-1)). In S114, the control amount calculation unit 76 calculates the backlash-eliminating duty Dg (equation (3-1)). Here, the backlash-eliminating time Xg and the backlash-eliminating duty Dg are linear functions of the idle running amount θoff, but they may also be calculated using a quadratic or higher function or a map. Also, a1, b1, etc. in the equations simply mean the slope and intercept in the linear function and can be set to any value for each equation.

[0041] Xg=a1×θoff+b1 (2-1) Dg=a2×θoff+b2 (3-1)

[0042] In addition, at least some of the idling amount θoff, the clearance eliminating duty Dg, and the clearance eliminating time Xg may be calculated as a function of the actuator temperature p (Equations (1-2), (2-2), and (3-2)). Note that (p) in the equations means that the parameters are functions of the actuator temperature (p).

[0043] θoff (i) =θoff (i-1) +(I (i) ×R(p) / Ke(p))×Δx (1-2) Xg=a1(p)×θoff+b1(p) ···(2-2) Dg=a2(p)×θoff+b2(p) ···(3-2)

[0044] In this embodiment, the output shaft angular velocity ω can be calculated with high accuracy by temperature-compensating the circuit resistance R and the torque constant Ke, thereby enabling the idling amount θj to be calculated appropriately. Furthermore, when the actuator temperature p is high, the torque required to start the motor 40 is small, while when the actuator temperature p is low, the torque required to start the motor 40 is large. Therefore, by making the clearance-eliminating time Xg and the clearance-eliminating duty Dg variable according to the actuator temperature p and increasing the clearance-eliminating time Xg and the clearance-eliminating duty Dg when the actuator temperature p is low compared to when the temperature is high, it is possible to reduce variations in clearance-eliminating performance due to temperature. Note that it is possible to calculate either the clearance-eliminating time Xg or the clearance-eliminating duty Dg so that it is variable according to temperature, without using the actuator temperature p as a parameter in the calculation of the other.

[0045] If it is determined that the drive mode is not the stop mode (S109: NO), the control unit 70 proceeds to S115, where it determines whether the drive mode is the backlash reduction mode. If it is determined that the drive mode is not the backlash reduction mode (S115: NO), the control unit 70 skips the processing from S116 onwards. If it is determined that the drive mode is the backlash reduction mode (S115: YES), it proceeds to S116.

[0046] In S116, the control unit 70 determines whether the clearance elimination time Xg has elapsed since the start of the clearance elimination control. If it is determined that the clearance elimination time Xg has not elapsed (S116: NO), the process proceeds to S117. If it is determined that the clearance elimination time Xg has elapsed (S115: YES), the process proceeds to S118.

[0047] In S117, the drive control unit 78 turns on the power supply to the motor 40 and drives the motor 40 in the direction opposite to that at the time of switching. At this time, the drive control unit 78 controls the duty to be the backlash-eliminating duty Dg. Also, the drive control unit 78 increments a backlash-eliminating control counter that counts the elapsed time since the start of the backlash-eliminating control.

[0048] In S118, the control unit 70 sets the drive mode to the standby mode and resets the backlash eliminating control counter. In S119, the drive control unit 78 turns off the power supply to the motor 40.

[0049] The switching process of this embodiment will be described based on the time chart of Fig. 6. In Fig. 6, the horizontal axis represents a common time axis, and from the top, the requested shift range, rotation angle, valley position determination flag Fvj, valley position determination counter, output shaft angular velocity, motor current value I, duty, and drive mode are shown.

[0050] Regarding the rotation angle, the output shaft angle θs based on the detection value of the output shaft sensor 55 is shown by a solid line, and the motor angle θm corresponding to the behavior of the motor 40 is shown by a two-dot chain line, with the scale being aligned by gear ratio conversion. Also, the motor angle when the detent roller 26 is at the bottom of the valley portion 211 is called "P valley," and the motor angle when it is at the bottom of the valley portion 212 is called "not P valley." This is the same as in Figure 8. Also, the duty is the ratio of the voltage application time in PWM control, and is defined as positive or negative depending on the direction of current flow.

[0051] At time x10, when the target shift range switches from P range to notP range, the drive mode changes from standby mode to switching mode, the motor 40 is driven at drive duty Dd, and at time x11, when the backlash in the forward direction is eliminated, drive of the output shaft 15 begins. At time x12, when the detent roller 26 overcomes the peak 215, the torque reverses and the backlash is eliminated in an instant on the opposite side, causing a sudden change in the output shaft angle θs.

[0052] At time x13, when the detent roller 26 reaches the bottom of the valley portion 212, the valley position determination counter is incremented. At time x14, when the valley position determination flag Fvj is turned on, power to the motor 40 is turned off and stop control is performed. During stop control, a current corresponding to the back electromotive force flows through the motor 40.

[0053] In this embodiment, the idle running amount θoff during stop control is calculated using the current value I during stop control. The idle running amount θoff calculated at time x15, which is the timing when stop control is completed, is shown in equation (4). In addition, the backlash eliminating duty Dg and backlash eliminating time Xg are calculated based on the idle running amount θoff.

[0054]

number

[0055] When the stop control ends at time x15, backlash-eliminating control is performed, supplying current in the direction opposite to the range switching direction. The backlash-eliminating control is performed for backlash-eliminating time Xg, with the duty set to backlash-eliminating duty Dg. At time x16, when the backlash-eliminating time Xg has elapsed since time x15, the backlash-eliminating control ends, the drive mode is switched to standby mode, and current to the motor 40 is turned off.

[0056] In this embodiment, the idle amount θoff is estimated using the current value I during stop control, and the backlash elimination duty Dg and backlash elimination time Xg are calculated based on the idle amount θoff. In other words, in this embodiment, the detection value of the output shaft sensor 55 is not used to estimate the idle amount θoff. Therefore, detection accuracy of the output shaft sensor 55 is not required. Furthermore, by estimating the idle amount θoff and performing backlash elimination control in accordance with the idle amount θoff, the motor shaft can be moved to a certain extent toward the traveling direction at the time of the next switch within the range of the backlash width Gw, thereby improving responsiveness.

[0057] As described above, in the parking lock system 1 including the electric actuator 10 having the motor 40, and the detent mechanism 20 having the detent plate 21 and the detent roller 26, the control device 60 controls switching of the detent mechanism 20 by driving the electric actuator 10 to move the detent roller 26. The detent plate 21 is formed with a plurality of valleys 211, 212 and ridges separating the valleys 211, 212. The detent roller 26 is movable between the valleys 211, 212 when the output shaft 15 is driven by the electric actuator 10.

[0058] The control device 60 includes a drive control unit 78 and a control amount calculation unit 76. The drive control unit 78 controls the drive of the motor 40 so that the detent roller 26 moves to the target valley portion. The control amount calculation unit 76 calculates the energization time and energization amount for backlash elimination control that returns the motor 40 in the reverse direction within the range of play between the motor 40 and the output shaft 15 after the detent roller 26 reaches the target valley portion.

[0059] The control amount calculation unit 76 estimates the amount of free running of the motor 40 within the range of play between the motor 40 and the output shaft 15 after the detent roller 26 has reached the target valley portion, using the current value I after power supply to the motor 40 is stopped. Furthermore, the control amount calculation unit 76 calculates, as control amounts, a backlash elimination time Xg and a backlash elimination duty Dg in the backlash elimination control, based on the estimated amount of free running.

[0060] This improves responsiveness by eliminating backlash in the opposite direction to the current drive direction, i.e., the next travel direction. Also, by estimating the free running amount θoff from the current value I after power is turned off and calculating the control amount, appropriate backlash elimination control can be performed without using the value of the rotation angle sensor that detects the rotation angle of the motor shaft.

[0061] The control amount calculation unit 76 estimates the free running amount using the temperature of the electric actuator 10. By temperature correcting the resistance value and torque constant used in the calculation to estimate the free running amount, the free running amount can be estimated with higher accuracy.

[0062] At least one of the backlash eliminating time Xg and the backlash eliminating duty Dg is variable in accordance with the actuator temperature p. This allows appropriate backlash eliminating control to be performed in accordance with the actuator temperature p.

[0063] (Second embodiment) The second embodiment is shown in Figures 7 and 8. The switching process of this embodiment will be described based on the flowchart in Figure 7. The processes of S201 to S206 are the same as the processes of S101 to S106 in Figure 4. In S206, if it is determined that the valley position determination flag Fvj is off (S206: NO), the process proceeds to S207, and if it is determined that the valley position determination flag Fvj is on (S206: YES), the process proceeds to S209.

[0064] In S207, it is determined whether the output shaft angular velocity ω is stable. Here, if the state in which the amount of change in the output shaft angular velocity ω is equal to or less than a predetermined value continues for a predetermined time, it is determined that the output shaft angular velocity ω is stable. If it is determined that the output shaft angular velocity ω is not stable (S207: NO), the process of S208 is skipped. If it is determined that the output shaft angular velocity ω is stable (S207: YES), the process proceeds to S208.

[0065] In S208, the control unit 70 stores the output shaft angular velocity ω in a stable region where the output shaft angular velocity ω is stable as the in-drive angular velocity ωd. The in-drive angular velocity ωd may be a value at any timing other than a region where the output shaft angle θs changes suddenly, such as when the detent roller 26 goes over a peak. However, it is preferable to store the value immediately before the motor stops. For example, the in-drive angular velocity ωd may be the value immediately before the inflection point of the output shaft angle θs before the detent roller 26 goes over a peak, or the value immediately before the output shaft angle θs stagnates as the detent roller 26 reaches the bottom. Alternatively, the in-drive angular velocity ωd may be a calculated value, such as an average value, using multiple detected values.

[0066] The processes of S209 and S210 are the same as the processes of S107 and S108 in Fig. 4. In S211, the control amount calculation unit 76 calculates the free running amount θj during valley position detection (Equation (5)). Xj in the equation is the arrival determination time.

[0067] θj=ωd×Xj (5)

[0068] The latter half of the process, which is initiated when a negative determination is made in S205, is the same as that shown in FIG. 5, except for the calculation of the backlash-eliminating time Xg and the backlash-eliminating duty Dg, and therefore will not be described here. In this embodiment, the backlash-eliminating time Xg and the backlash-eliminating duty Dg are calculated based on the idle running amount θj during valley position detection and the idle running amount θoff during stop control (Equations (6-1) and (7-1)). At least one of the backlash-eliminating duty Dg and the backlash-eliminating time Xg may be calculated as a function of the actuator temperature p (Equations (6-2) and (7-2)).

[0069] Xg=a1×(θj+θoff)+b1 ···(6-1) Dg=a2×(θj+θoff)+b2 (7-1)

[0070] Xg=a1(p)×(θj+θoff)+b1(p) ···(6-2) Dg=a2(p)×(θj+θoff)+b2(p) ···(7-2)

[0071] The switching process of this embodiment will be described based on the time chart of Fig. 8. The process from time x20 to time x22 is the same as the process from x10 to x12 in Fig. 6. In this embodiment, the driving angular velocity ωd is stored in the region where the output shaft angular velocity ω is stable between time x21 and time x22.

[0072] At time x23, when the detent roller 26 reaches the bottom of the valley portion 212, the valley position determination counter is incremented, and at time x24 when the arrival determination time Xj has elapsed, the valley position determination flag Fvj is turned on, and power to the motor 40 is turned off to perform stop control. In addition, the output shaft angular velocity ω during valley position determination is regarded as the driving angular velocity ωd, and the idling amount θj during valley position detection is calculated based on the driving angular velocity ωd and the arrival determination time Xj.

[0073] The processing during the stop control performed from time x24 to time x25 is the same as in the first embodiment. When the stop control ends at time x25, the backlash eliminating time Xg and backlash eliminating duty Dg are calculated based on the idle running amounts θj and θoff. The processing after the backlash eliminating control is the same as in the first embodiment.

[0074] In this embodiment, the control amount calculation unit 76 estimates the free running amount from the free running amount θoff estimated using the current value I during stop control that stops the motor 40, and the free running amount θj during the arrival determination time Xj from when the detent roller 26 reaches the target valley until power supply is stopped. In this embodiment, the free running amount θj is estimated using the output shaft angular velocity ω and the arrival determination time Xj. This makes it possible to estimate the free running amount with greater accuracy. In addition, the same effects as those of the above embodiment are achieved.

[0075] In the embodiment, the parking lock system 1 corresponds to the "drive system," the electric actuator 10 corresponds to the "actuator," the motor 40 corresponds to the "drive source," the detent plate 21 corresponds to the "detent member," the detent roller 26 corresponds to the "engagement member," and the control device 60 corresponds to the "actuator control device."

[0076] In addition, the backlash eliminating control corresponds to the "return control," the backlash eliminating time Xg corresponds to the "energization time in the return control," the backlash eliminating duty Dg corresponds to the "energization amount in the return control," the idle running amount θoff corresponds to the "idle running amount during stop control," and the idle running amount θj corresponds to the "idle running amount during arrival determination." In addition, the target valley when switching from P range to notP range is valley 212, and the target valley when switching from notP range to P range is valley 211.

[0077] (Other embodiments) In the above embodiment, the drive source is a brushed DC motor. In other embodiments, the drive source may be a motor other than a brushed DC motor, or may be a solenoid or the like. In the above embodiment, the electric actuator is a rotary type, but in other embodiments, it may be a linear type.

[0078] In the above embodiment, the electric actuator is applied to a parking lock system. In other embodiments, the electric actuator may be applied to an in-vehicle system other than a parking lock system or a drive system other than an in-vehicle system.

[0079] The present invention may be characterized in that "at least one of the energization time and the energization amount in the return control is variable depending on the temperature of the actuator."

[0080] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer. As described above, the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0081] 1. Parking lock system (drive system) 10. Electric actuator (actuator) 15 Output shaft 20: Detent mechanism 21: Detent plate (detent member) 221, 222... Valley 215... Peak 26 Detent roller (engagement member) 40 Motor (drive source) 55 Output shaft sensor 60...Control device (actuator control device) 76: Control amount calculation unit 78: Drive control unit

Claims

1. an actuator (10) having a drive source (40); a detent mechanism (20) including a detent member (21) having a plurality of valleys (211, 212) and peaks (215) separating the valleys, and an engaging member (26) that is movable between the valleys when the output shaft (15) is driven by the actuator; In a drive system (1) comprising: an actuator control device that controls switching of the detent mechanism by driving the actuator and moving the engagement member, a drive control unit (78) that controls the drive of the drive source so that the engaging member moves to the target valley portion; a control amount calculation unit (76) that calculates a current application time and a current application amount of a return control for returning the drive source in a reverse direction within a range of play between the drive source and the output shaft after the engagement member reaches the target valley portion; Equipped with The control amount calculation unit estimates an amount of free running of the drive source within a range of play between the drive source and the output shaft after the engagement member has reached the target valley portion, using a current value after power supply to the drive source has been stopped, and calculates a current application time and current amount for the return control based on the estimated amount of free running.

2. The actuator control device according to claim 1 , wherein the control amount calculation unit estimates the free running amount using a temperature of the actuator.

3. 3. The actuator control device according to claim 1, wherein the control amount calculation unit estimates the free running amount from a stop control free running amount estimated using a current value during stop control that stops the drive source, and an arrival determination free running amount during an arrival determination time from when the engagement member reaches the target valley portion until power supply is stopped.

4. 3. The actuator control device according to claim 1, wherein at least one of the energization time and the energization amount in the return control is variable depending on the temperature of the actuator.

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