JP2023159723A - Actuator control device - Google Patents

Abstract

To provide an actuator control device capable of appropriately performing position determination.SOLUTION: In a park lock system including an electric actuator having a motor 40, a detent mechanism, and a position sensor 55, a control device 60 controls switching of the detent mechanism by driving of the motor 40. A detent roller of the detent mechanism can move between troughs by an output shaft driven by the electric actuator. A control unit 70 of the control device 60 includes a position determining unit 73 for determining that the detent roller is dropped to the lowermost bottom of a target trough when moving the detent roller to the target trough. The position determining unit 73 sets a mask time at which position determination is not performed after load torque is inverted by the detent roller getting over a crest, and executes position determination with the usage of a detection value of the position sensor 55 after the mask time.SELECTED DRAWING: Figure 3

Description

The present invention relates to an actuator control device.

Conventionally, a shift-by-wire system that electrically controls a shift range switching mechanism of an automatic transmission is known. For example, in Patent Document 1, an output shaft sensor that detects the rotation angle of the output shaft is provided, and based on the output signal of the output shaft sensor, it is determined where the output shaft is located among a plurality of range determination ranges. ing.

Japanese Patent Application Publication No. 2018-179142

For example, when determining whether the locking part has moved to the bottom of the concave part of the detent plate based on the number of rotations or elapsed time, the play between the motor shaft and the output shaft is relatively large, and vibrations within the play can be detected. If this occurs, there is a possibility that it may not be possible to appropriately determine that the locking portion is at the bottom of the recess.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an actuator control device that can appropriately perform position determination.

An actuator control device (60) of the present invention is a drive system (1) that includes an actuator (10) having a drive source (40), a detent mechanism (20), and a position sensor (55). controls switching of the detent mechanism. The detent mechanism includes a detent member (21) and an engagement member (26). The detent member is formed with a plurality of valleys (211, 212) and a peak (215) that separates the valleys. The engagement member is movable between the troughs by driving the output shaft (15) by an actuator. The position sensor can detect the position of the output shaft.

The actuator control device includes a position determination unit (73) that determines that the engagement member has fallen to the bottom of the target valley when moving the engagement member to the target valley. The position determining section provides a mask time in which position determination is not performed after the load torque is reversed by the engagement member overcoming the peak, and after the mask time, performs position determination using the detected value of the position sensor. Thereby, transient changes due to load torque reversal can be masked, and position determination can be performed appropriately.

FIG. 1 is a schematic configuration diagram showing a park lock system according to a first embodiment. FIG. 1 is a perspective view showing an electric actuator according to a first embodiment. FIG. 1 is a block diagram showing a control device according to a first embodiment. FIG. 3 is a schematic diagram showing a motor and a detent mechanism according to the first embodiment. (a) is a behavior simulation result of the motor angle, sensor angle, and output shaft angle, and (b) is an enlarged view of the Vb section in FIG. 5(a). FIG. 3 is a diagram illustrating a sensor angle maximum value according to the first embodiment. It is a flow chart explaining drive mode switching processing by a 1st embodiment. It is a flowchart explaining valley position determination processing by a 1st embodiment. It is a flowchart explaining valley position determination processing by a 1st embodiment. (a) is a diagram showing the relationship between current and mask time, (b) is a diagram showing the relationship between temperature and mask time, and (c) is a diagram showing the relationship between voltage and mask time. , (d) are diagrams showing the relationship between sensor rotation speed and mask time. FIG. 3 is a diagram showing the relationship between range switching direction and detent torque. It is a figure showing the relationship between range switching direction and mask time. It is a time chart explaining valley position determination processing by a 1st embodiment. It is a time chart explaining valley position determination processing by a 1st embodiment. It is a flowchart explaining valley position determination processing by a 2nd embodiment. It is a flowchart explaining valley position determination processing by a 2nd embodiment. It is a time chart explaining valley position determination processing by a 2nd embodiment.

Hereinafter, an actuator control device according to the present invention will be explained based on the drawings. Hereinafter, in a plurality of embodiments, substantially the same configurations are denoted by the same reference numerals, and description thereof will be omitted.

(First embodiment)
A first embodiment is shown in FIGS. 1 to 14. As shown in FIG. 1, an electric actuator 10 is applied to a park lock system 1. The park lock system 1 includes an electric actuator 10, a detent mechanism 20, and a parking lock mechanism 30. The electric actuator 10 is rotary and includes, for example, a brushed DC motor, a reduction gear mechanism, and the like. The electric actuator 10 drives the detent mechanism 20 by rotating the output shaft 15.

The detent mechanism 20 includes a detent plate 21, a detent spring 25, and the like, and transmits the rotational driving force output from the electric actuator 10 to the parking lock mechanism 30.

The detent plate 21 is fixed to the output shaft 15 and driven by the electric actuator 10. Two troughs 211 and 212 and a peak 215 separating the troughs 211 and 212 are provided on the detent spring 25 side of the detent plate 21.

The detent spring 25, which is a biasing member, is an elastically deformable plate-like member, and a detent roller 26 is provided at the tip. The detent spring 25 urges the detent roller 26 toward the center of rotation of the detent plate 21.

When a predetermined rotational force or more is applied to the detent plate 21, the detent spring 25 is elastically deformed, and the detent roller 26 moves between the troughs 211 and 212. When the detent roller 26 fits into either of the valleys 211 and 212, the swinging of the detent plate 21 is restricted, and the state of the parking lock mechanism 30 is fixed.

The parking lock mechanism 30 includes a parking rod 31, a cone 32, a parking lever 33, a shaft portion 34, and a parking gear 35. The parking rod 31 is formed in a substantially L-shape, and one end 311 side is fixed to the detent plate 21. A cone body 32 is provided on the other end 312 side of the parking rod 31 . The conical body 32 is formed so that its diameter decreases toward the other end 312 side. When the detent plate 21 rotates in the direction in which the detent roller 26 fits into the trough 211 corresponding to the P range, the cone 32 moves in the direction of arrow P.

The parking lever 33 is provided to be in contact with the conical surface of the conical body 32 and swingable about the shaft portion 34 . A convex portion 331 that can mesh with the parking gear 35 is provided on the parking gear 35 side of the parking lever 33. When the cone 32 moves in the direction of arrow P due to the rotation of the detent plate 21, the parking lever 33 is pushed up and the convex portion 331 and the parking gear 35 are engaged. On the other hand, when the cone 32 moves in the direction of the arrow notP, the engagement between the convex portion 331 and the parking gear 35 is released.

The parking gear 35 is connected to a drive shaft (not shown), and is provided so as to be able to mesh with a convex portion 331 of the parking lever 33. When the parking gear 35 and the convex portion 331 mesh with each other, rotation of the drive shaft is restricted. When the shift range is a not P range, which is a range other than P, the parking gear 35 is not locked by the parking lever 33, and the rotation of the drive shaft is not hindered by the parking lock mechanism 30. Further, when the shift range is in the P range, the parking gear 35 is locked by the parking lever 33, and rotation of the drive shaft is restricted.

Hereinafter, the trough 211 into which the detent roller 26 fits when in the P range will be referred to as the "P trough", and the trough 212 into which the detent roller 26 will fit into the not P range will be referred to as the "not P trough", troughs 211, 212. Let the bottom of the valley be the "bottom".

As shown in FIG. 2, the electric actuator 10 includes a motor 40, a speed reduction mechanism 42, a case 51, a board cover 57, and the like. The motor 40 is placed horizontally on the board cover 57 so that the motor shaft is substantially parallel to the bottom surface of the case 51.

The speed reduction mechanism 42 includes a worm gear 43, a helical gear 44, an intermediate gear 45, a driven plate 46, and a driven shaft 47. The worm gear 43 rotates together with the motor shaft of the motor 40. The helical gear 44 meshes with the large diameter portions of the worm gear 43 and intermediate gear 45. The intermediate gear 45 has a large diameter portion and a small diameter portion, the large diameter portion meshes with the helical gear 44, and the small diameter portion meshes with the driven plate 46.

Although the driven plate 46 and the driven shaft 47 are formed integrally, they may be separate bodies. The driven shaft 47 and the output shaft 15 are connected through a spline joint. Thereby, the rotation of the motor 40 is transmitted to the output shaft 15 via the worm gear 43, helical gear 44, intermediate gear 45, driven plate 46, and driven shaft 47.

The case 51 is made of, for example, resin, and has a cylindrical portion 54 formed at a location corresponding to the driven shaft 47 . The cylindrical portion 54 is formed in a cylindrical shape that opens toward the driven shaft 47, and is provided so as to be able to come into contact with the driven shaft 47 at its end surface. Due to the driven shaft 47 and the cylindrical portion 54 coming into contact with each other, the cylindrical portion 54 receives a load in the axial direction of the driven shaft 47 .

The driven shaft 47 is provided with a sensor magnet (not shown). Further, a position sensor 55 (see FIG. 3) is provided inside the cylindrical portion 54 at a location facing the driven shaft 47. In this embodiment, the driven shaft 47 is used as a "sensor shaft", and the rotational position of the output shaft 15 is detected by the position sensor 55. The board cover 57 is fixed to the case 51, and has a board (not shown) provided therein. Various electronic components constituting the control device 60 are mounted on the board.

As shown in FIG. 3, the control device 60 includes a drive circuit 61, a control section 70, and the like. The drive circuit 61 has a drive element (not shown). The control unit 70 is mainly composed of a microcomputer, and internally includes a CPU, ROM, RAM, I/O, and a bus line connecting these components, all of which are not shown. Each process in the control unit 50 may be a software process in which a CPU executes a program stored in a physical memory device such as a ROM (i.e., a readable non-temporary tangible recording medium), or It may also be a hardware process using a dedicated electronic circuit.

The control unit 70 acquires the requested shift range, sets a target range, and controls the drive of the electric actuator 10 so that the detent roller 26 is located in the valleys 211 and 212 according to the target range. The control unit 70 includes a signal acquisition unit 71, a rotation calculation unit 72, a position determination unit 73, a threshold setting unit 74, a drive control unit 75, and the like as functional blocks. The signal acquisition unit 71 acquires a position detection signal from the position sensor 55, a signal related to a requested shift range from a higher-level ECU (not shown), etc., a sensor signal related to the current, voltage, temperature, etc. of the motor 40, and the like.

The rotation calculation unit 72 calculates a sensor angle θs, which is the rotation angle of the driven shaft 47, and a sensor rotation speed Ns, which is the rotation speed of the driven shaft 47, based on the detected value of the position sensor 55. The sensor angle θs and the sensor rotation speed Ns can be regarded as values related to the output shaft 15 when the driven shaft 47 and the output shaft 15 are rotating together with no backlash.

The position determination unit 73 determines the position of the detent roller 26 in the detent mechanism 20. The threshold setting unit 74 sets a threshold for determining the position of the detent roller 26. The position determination of the detent roller 26 and the threshold value setting related to the position determination will be described later. The drive control unit 75 controls the drive of the motor 40 by controlling the on/off operation of the drive element of the drive circuit 61 .

FIG. 4 schematically shows the play between the motor 40 and the output shaft 15, and shows how the detent roller 26 moves through the troughs 211 and 212, assuming that the left-right direction on the page is the rotation direction. Note that, in reality, the detent roller 26 moves between the troughs 211 and 212 due to the rotation of the detent plate 21 that rotates together with the output shaft 15. In FIG. 4, the operations of the motor 40 and the like are indicated by dashed-dotted arrows.

A speed reduction mechanism 42 is provided between the motor 40 and the output shaft 15, and there is play. Hereinafter, the total play between the motor shaft and the driven shaft 47, which is the sensor shaft, will be referred to as internal play Gm, and the play between the driven shaft 47 and the output shaft 15 will be referred to as spline play Gs, and internal play Gm and spline play Gs will be referred to as appropriate. The total amount is simply called "gata".

When switching the shift range from the P range to the not P range, the internal play Gm and the spline play Gs are reduced toward the traveling direction side, and the detent roller 26 is pushed up toward the mountain portion 215 with the motor shaft leading. When the detent roller 26 passes over the peak 215, the spring force of the detent spring 25 causes the output shaft 15 to move in advance toward the valley 212. When the detent roller 26 passes over the peak 215, the direction of the torque is reversed and the backlash is suddenly clogged on the opposite side, so the detected value of the position sensor 55 fluctuates sharply.

Furthermore, in this embodiment, the worm gear 43 is used in the speed reduction mechanism 42, and the driven torque is relatively large. Specifically, the driven torque in the deceleration mechanism 42 is larger than the biasing torque by which the detent spring 25 biases the detent roller 26 toward the valley bottom. Therefore, when switching the range, if the motor 40 is de-energized after going over the peak 215 but before reaching the bottom, the detent roller will stop at the de-energized position depending on the amount of backlash. There is a possibility that you will not be able to get the 26 to the bottom. Therefore, in this embodiment, after determining that the detent roller 26 is stopped at the bottom, the power supply is turned off.

FIG. 5 shows simulation results of the motor angle θm, sensor angle θs, and output shaft angle θd when switching from the P range to the notP range, with the horizontal axis representing time and the vertical axis representing angle.

In this embodiment, since there is a spline play Gs between the output shaft 15 and the sensor shaft, even if the detent roller 26 is stopped at the trough 212, if the driven shaft 47 vibrates within the range of the spline play Gs, The detected value of the position sensor 55 vibrates. If the sensor shaft oscillates due to such mechanical play, accurate angle calculation cannot be performed until the oscillation stops.

Here, focusing on the fact that the driven shaft 47 does not move beyond the range of the spline play Gs after the detent roller 26 falls into the valley 212, the sensor angle θs after the detent roller 26 has climbed over the peak 215 is By holding the maximum value or the minimum value and detecting that the sensor shaft does not move by more than the backlash width, it is determined that the detent roller 26 has fallen to the bottom of the valley. Hereinafter, the maximum value of the sensor angle θs will be referred to as the maximum sensor angle value θmax, and the minimum value of the sensor angle θs will be referred to as the minimum sensor angle value θmin.

FIG. 6 shows the sensor angle θs and the maximum sensor angle value θmax when switching from the P range to the notP range, with the horizontal axis representing time and the vertical axis representing angle. In the example of FIG. 6, the sum of the internal play Gm and the spline play Gs is larger than the angle between the peak 215 and the trough 212, and when the detent roller 26 climbs over the peak 215, the output shaft 15 moves inside the play. By rotating, the detent roller 26 moves to the trough 212 in a substantially unloaded state.

As shown in FIG. 6, when switching from the P range to the notP range, the maximum sensor angle value θmax is held, and the maximum value change Δθmax, which is the amount of change in the maximum sensor angle value θmax, becomes smaller than the position determination threshold Nth. If so, it is determined that the detent roller 26 has fallen into the trough 212. Furthermore, since the sensor angle θs is set to decrease as the output shaft 15 rotates when switching from the notP range to the P range, the same determination is made by holding the minimum sensor angle value θmin.

Further, when the detent roller 26 crosses the mountain portion 215 and the backlash reduction direction is reversed, the driven shaft 47 vibrates due to its kinetic energy, so that the detected value of the position sensor 55 vibrates. In this embodiment, the sensor shaft is the driven shaft 47, and the behavior of the output shaft 15 cannot be directly detected. Therefore, when the sensor angle θs oscillates after the backlash reduction direction is reversed, the detent roller 26 is at the bottom. There is a risk of erroneously determining whether or not this is the case. Therefore, in this embodiment, a mask time Xmc is provided in which the valley position determination is not performed for a predetermined period of time after the detent roller 26 crosses the peak portion 215 and the backlash reduction direction is reversed.

The drive mode switching process of this embodiment will be explained based on the flowchart of FIG. The processes shown in FIG. 5 and the like are executed by the control unit 70 at predetermined intervals. Hereinafter, "steps" such as step S101 will be omitted and simply referred to as "S".

In S101, the control unit 70 determines whether the drive mode is standby mode. If it is determined that the drive mode is not standby mode (S101: NO), the process moves to S104. If it is determined that the drive mode is standby mode (S101: YES), the process moves to S102.

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 is continued. If it is determined that the target range has been switched (S102: YES), the process moves to S103, the drive mode is changed from standby mode to switching mode, and driving of the motor 40 is started.

In S104, which is proceeded to when it is determined that the drive mode is not the standby mode (S101: NO), 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 (S104: NO), the process moves to S107. If it is determined that the drive mode is the switching mode (S104: YES), the process moves to S105.

In S105, the control unit 70 determines whether the valley position determination flag Fvj is turned on. Details of the process related to the valley position determination flag Fvj will be described later. If it is determined that the valley position determination flag Fvj is off (S105: NO), the switching mode is continued. If it is determined that the valley position determination flag Fvj is turned on (S105: YES), the process moves to S106, and the drive mode is changed from the switching mode to the stop mode. In the stop mode, the back electromotive current is circulated to generate braking force.

In S107, which is proceeded to when it is determined that the drive mode is not the switching mode (S104: NO), the control unit 70 determines whether the drive mode is the stop mode. If it is determined that the drive mode is not the stop mode (S107: NO), the process from S108 onwards is skipped. If it is determined that the drive mode is the stop mode (S107: YES), the process moves to S108.

In S108, the control unit 70 determines whether the stop mode continuation time Xst has elapsed since the start of the stop mode. If it is determined that the stop mode duration time Xst has not elapsed (S108: NO), the stop mode time counter is incremented. If it is determined that the stop mode duration time Xst has elapsed (S108: YES), the process moves to S109, and the drive mode is changed from the stop mode to the standby mode. It also resets the stop mode clock counter.

The valley position determination process of this embodiment will be explained based on the flowcharts of FIGS. 8 and 9. In S201, 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 (S201: NO), the process moves to S222. If it is determined that the drive mode is the switching mode (S201: YES), the process moves to S202.

In S202, the position determination unit 73 determines whether the mountain crossing determination flag Fmj is on. If it is determined that the mountain crossing determination flag Fmj is on (S202: YES), the process moves to S206 in FIG. If it is determined that the mountain crossing determination flag Fmj is off (S202: NO), the process moves to S203.

In S203, the position determination unit 73 determines whether the angle change amount Δθ, which is the amount of change between the previous value and the current value of the sensor angle θs, which is the detected angle of the position sensor 55, is greater than or equal to the sudden change determination threshold value θth. The sudden change determination threshold value θth is a value corresponding to the rotation angle when the play is jammed on the opposite side when the detent roller 26 climbs over the mountain portion 215, and is set according to the shape of the detent plate 21 and the size of the play. . The sudden change determination threshold value θth may be a different value depending on the shape of the detent plate 21 when switching from the P range to the notP range and when switching from the notP range to the P range. If it is determined that the angle change amount Δθ is smaller than the sudden change determination threshold value θth (S203: NO), the detent roller 26 is climbing up a mountain and continues the current driving state. If it is determined that the angle change amount Δθ is greater than or equal to the sudden change determination threshold value θth (S203: YES), the process moves to S204.

In S204, the position determining unit 73 determines that the detent roller 26 has climbed over the mountain portion 215, and turns on the mountain crossing determination flag Fmj. Further, in the control unit 70, information related to the sensor rotation speed Ns until the mountain crossing determination flag Fmj is turned on is stored in association with time information, and in S205, the control unit 70 stores information regarding the sensor rotation speed Ns until the mountain crossing determination flag Fmj is turned on. The sensor rotation speed Ns before a predetermined time Xc is obtained as the rotation speed Nc during mountain climbing. The predetermined time period Xc is set such that a value when the detent roller 26 is climbing a mountain and the sensor rotation speed Ns is stable can be obtained as the mountain climbing rotation speed Nc. Note that it is desirable to obtain the value immediately before the rotation speed of the detent roller 26 suddenly changes when the detent roller 26 climbs over the mountain as the rotation speed Nc during mountain climbing. Alternatively, a calculated value such as an average value using a plurality of values obtained in a section where the sensor rotation speed Ns is stable may be used as the rotation speed Nc during mountain climbing.

As shown in FIG. 9, in S206 when it is determined that the mountain crossing determination flag Fmj is on (S202: YES), a mask time Xmc is set. The mask time Xmc is set according to the vibration state of the driven shaft 47 caused by the kinetic energy that the driven shaft 47 has when the backlash is reversed when going over a mountain. Specifically, the mask time Xmc is set to, for example, 5 [ms] as a reference time, and is varied according to environmental conditions. For example, when the load torque is large, the torque required for switching is large, so the motor current becomes large. Furthermore, since the suction force is large, the speed at which the detent roller 26 moves toward the bottom of the valley increases. Therefore, as shown in FIG. 10(a), the mask time Xmc is set to become longer as the motor current becomes larger.

As shown in FIG. 10(b), the higher the temperature is, the smaller the viscous resistance is and the easier it is to vibrate, so the mask time Xmc is set to be longer as the temperature is higher. As shown in FIG. 10(c), the higher the voltage, the more likely the switching torque will be produced, so the mask time Xmc is set to be longer as the voltage applied to the motor 40 is higher. Furthermore, as shown in FIG. 10(d), the higher the rotational speed, the easier it is to vibrate, so the mask time Xmc is set to be longer as the rotational speed is higher.

Furthermore, as shown in Fig. 11, the detent torque differs depending on the driving direction, and the detent torque is larger when switching from the P range to the notP range than when switching from the notP range to the P range, and the vibration is growing.

Therefore, in this embodiment, the masking time Xmc is made variable depending on the driving direction. Specifically, as shown in FIG. 12, the mask time Xmc is set to be longer when switching from the P range to the notP range than when switching from the notP range to the P range. Mask time Xmc is obtained from a map according to motor current, temperature, applied voltage, motor rotation speed, and drive direction. For example, values are obtained using maps individually set for each parameter, and the largest value is set as the mask time Xmc.

Returning to FIG. 9, in S207, the position determination unit 73 determines whether the mask time Xmc has elapsed since the mountain crossing determination flag Fmj was turned on. If it is determined that the mask time Xmc has not elapsed since the mountain crossing determination flag Fmj was turned on (S207: NO), the process moves to S208 and the mask time counter is incremented. If it is determined that the mask time Xmc has elapsed since the mountain crossing determination flag Fmj was turned on (S207: YES), the process moves to S209.

In S209, the position determining unit 73 determines whether the current driving direction is a direction in which the sensor angle θs increases. In this embodiment, an affirmative determination is made when switching from the P range to the notP range, and a negative determination is made when switching from the notP range to the P range. If it is determined that the current driving direction is the direction in which the sensor angle θs decreases (S209: NO), the process moves to S215. If it is determined that the current driving direction is the direction in which the sensor angle θs increases (S209: YES), the process moves to S210.

In S210, the position determination unit 73 determines whether the current value θs(n) of the sensor angle is larger than the held maximum value θmax of the sensor angle. Hereinafter, a subscript (n) for the current value and a subscript (n-1) for the previous value are attached as appropriate. If it is determined that the current value θs(n) of the sensor angle is larger than the held maximum sensor angle value θmax (S210: YES), the process moves to S210, and the current value θs(n) of the sensor angle is set to the maximum sensor angle. It is held as the value θmax. If it is determined that the current sensor angle value θs(n) is less than or equal to the held sensor angle maximum value θmax (S210: NO), the sensor angle maximum value θmax is not updated and the process moves to S212.

In S212, the position determination unit 73 determines that the maximum value change Δθmax (see equation (1-1)), which is the absolute value of the difference between the current value and the previous value of the held sensor angle maximum value θmax, is used for position determination. It is determined whether or not it is smaller than a threshold value Nth. In this embodiment, the position determination threshold Nth is set for each range change. The position determination threshold Nth is a value obtained by multiplying the rotational speed Nc during mountain climbing by a safety factor k, which is a value smaller than 1 (see equation (2)). If necessary, conversion may be performed to match the scale. In this embodiment, the position determination threshold Nth is set for each range change.

Δθmax=|θmax(n)-θmax(n-1)| ...(1-1)
Nth=Nc×k...(2)

The safety factor k is an arbitrary value of 1 or less (for example, 0.7). Furthermore, the safety factor k may be variable depending on the environmental conditions so that the value is equal to or less than an arbitrary reference value (for example, 0.7). For example, the safety factor when the maximum voltage drops is used as the reference value, and is set so that the larger the voltage applied to the motor 40, the smaller the value becomes. Further, in the case of high temperature, the rotation speed of the motor 40 increases, so the safety factor k is set to a smaller value as the temperature is higher. Furthermore, the smaller the load torque before crossing the mountain, the larger the sensor rotation speed Ns, so the safety factor k is set to a smaller value as the load torque is smaller. The safety factor k is obtained, for example, from a map according to voltage, temperature, and load torque. For example, values are obtained using maps individually set for each parameter, and the smallest value is set as the safety factor k.

If it is determined that the maximum value change amount Δθmax is smaller than the position determination threshold Nth (S212: YES), the process moves to S213, and a counter related to measuring the determination waiting time Xh is incremented. If it is determined that the maximum value change amount Δθmax is equal to or greater than the position determination threshold value Nth (S212: NO), the process moves to S214, and a counter for measuring the determination standby time Xh is reset.

When it is determined that the current driving direction is the direction in which the sensor angle θs decreases (S209: NO), in S215, the position determination unit 73 determines that the current value θs(n) of the sensor angle is held. It is determined whether the sensor angle is smaller than the minimum sensor angle value θmin. If it is determined that the current value θs(n) of the sensor angle is smaller than the held minimum sensor angle value θmin (S215: YES), the process moves to S216, and the current value θs(n) of the sensor angle is set as the minimum sensor angle value. It is held as the value θmin. If it is determined that the current value θs(n) of the sensor angle is greater than or equal to the held minimum sensor angle value θmin (S215: NO), the minimum sensor angle value θmin is not updated and the process moves to S217.

In S217, the position determination unit 73 determines that the minimum value change Δθmin (see equation (1-2)), which is the difference between the current value and the previous value of the held sensor angle minimum value θmin, is smaller than the position determination threshold Nth. Decide whether or not. If it is determined that the minimum value change amount Δθmin is smaller than the position determination threshold Nth (S217: YES), the process moves to S218, and a counter for measuring the determination waiting time Xh is incremented. If it is determined that the minimum value change amount Δθmin is greater than or equal to the position determination threshold value Nth (S217: NO), the process moves to S219, and a counter for measuring the determination standby time Xh is reset.

Δθmin=|θmin(n)-θmin(n-1)| ...(1-2)

In S220, which follows S213, S214, S218, or S219, the position determination unit 73 determines whether the determination waiting time Xh is equal to or longer than the valley position determination time Xv. If it is determined that the determination waiting time Xh is smaller than the valley position determination time Xv (S220: NO), S221 is skipped. If it is determined that the determination waiting time Xh is longer than the valley position determination time Xv (S220: YES), the process moves to S221 and the valley position determination flag Fvj is turned on.

Returning to FIG. 8, in S222 when it is determined that the drive mode is not the switching mode (S201: NO), the position determination unit 73 turns off the valley position determination flag Fvj and the mountain crossing determination flag Fmj. In S223, the position determination unit 73 resets the held maximum sensor angle value θmax or minimum sensor angle value θmin. Further, the position determination unit 73 resets the counters related to the determination standby time Xh and the mask time Xmc.

The valley position determination process of this embodiment will be explained based on the time charts of FIGS. 13 and 14. FIG. 13 shows the switching from the P range to the notP range, with the common time axis as the horizontal axis, and from the top, the target shift range, rotation angle, rotation speed, mountain crossing determination flag Fmj, position determination threshold Nth, maximum sensor angle The value θmax, the maximum value change amount Δθmax, the valley position determination flag Fvj, and the duty instruction value are shown. Regarding the rotation angle and rotation speed, the sensor angle θs based on the detected value of the position sensor 55 is shown as a solid line, the motor angle θm depending on the behavior of the motor 40 is shown as a chain double-dashed line, and the output shaft angle θd depending on the behavior of the output shaft 15 is shown as a broken line. The scales are aligned by gear ratio conversion. Further, the rotation speed of the motor 40 is assumed to be motor rotation speed Nm. Further, the motor angle when the detent roller 26 is at the bottom of the trough 211 is "P", and the motor angle when the detent roller 26 is at the bottom of the trough 212 is "notP".

As shown in FIG. 13, when the target shift range is switched from the P range to the notP range at time x10, the motor 40 is driven, and at time x11, when the backlash has become clogged, the sensor shaft also starts rotating, and as it rotates, the sensor shaft starts rotating. The sensor angle θs increases. Further, in this embodiment, the sensor rotation speed Ns is stored in association with time information at least until the mountain crossing determination flag Fmj is set. In FIG. 13 and the like, the duty instruction value when driving the motor is set to 100 [%], but it may be set to any value.

At time x12, when the detent roller 26 passes over the peak 215, the torque is reversed and the backlash is suddenly jammed on the opposite side, causing a large change in the detected value of the position sensor 55. In the present embodiment, when the angle change amount Δθ, which is the difference between the previous value and the current value of the sensor angle θs, exceeds the sudden change determination threshold θth, it is determined that the detent roller 26 has climbed over the mountain portion 215, and the mountain crossing determination flag is Turn on Fmj. Further, the sensor rotation speed Ns at a timing before a predetermined time Xc from time x12 is obtained as the mountain climbing rotation speed Nc, and the position determination threshold Nth is set (see equation (2)).

When the sum of the internal play Gm and the spline play Gs is larger than the angle between the peak 215 and the trough 212, the output shaft 15 rotates in a substantially no-load state within the range of the play width, resulting in detent. Even when the roller 26 is sucked to the bottom of the valley and the detent roller 26 reaches the bottom, the sensor angle θs oscillates. In particular, immediately after the detent roller 26 climbs over the mountain portion 215, the vibrations are large. Therefore, the sensor angle maximum value θmax is not held until the mask time Xmc has elapsed after it is determined that the detent roller 26 has climbed over the mountain portion 215.

At time x13, when the mask time Xmc has elapsed since it is determined that the detent roller 26 has climbed over the mountain portion 215, the holding process for the sensor angle maximum value θmax is started. That is, in order to mask the hold processing between time x12 and time x13, the maximum values MAX1 and MAX2 detected during this period are not held, but the maximum value MAX3 detected after the mask time Xmc has elapsed is held. Incidentally, after the mask time Xmc, the transition to the first peak is as follows.

At time x14, when the maximum value change amount Δθmax becomes smaller than the position determination threshold Nth, measurement of the determination standby time Xh is started. At time x15, when the state in which the maximum value change amount Δθmax is smaller than the position determination threshold value Nth continues over the valley position determination time Xv, the valley position determination flag Fvj is turned on. Then, the duty instruction value is set to 0 [%], and the power to the motor 40 is turned off. At time x15, the vibration has not settled down to the sensor angle θs, but if the vibration amplitude is within the range of the spline play Gs, the detent roller 26 does not move, so the detent roller 26 does not move until the vibration at the sensor angle θs converges. 26 can be determined to have stopped at the bottom of the valley portion 212.

FIG. 14 shows the switching from the notP range to the P range, with the common time axis as the horizontal axis, and starting from the top, the target shift range, rotation angle, rotation speed, mountain crossing determination flag Fmj, position determination threshold Nth, and sensor angle. The minimum value θmin, the minimum value change amount Δθmin, the valley position determination flag Fvj, and the duty instruction value are shown. The valley position determination process when switching from the notP range to the P range is generally the same as the process when switching from the P range to the notP range, except that the rotation direction is different.

When the target shift range is switched from the notP range to the P range at time x20, the motor 40 is driven, and at time x21 when the backlash has become clogged, the sensor shaft also starts rotating, and the sensor angle θs decreases as it rotates. Further, the sensor rotation speed Ns is stored in association with time information at least until the mountain crossing determination flag Fmj is set.

At time x22, when the detent roller 26 climbs over the peak 215, the sensor angle θs changes significantly. When the angle change amount Δθ becomes greater than or equal to the sudden change determination threshold value θth, it is determined that the detent roller 26 has climbed over the mountain portion 215, and the mountain crossing determination flag Fmj is turned on. Further, the sensor rotation speed Ns at a timing before a predetermined time Xc from time x22 is obtained as the mountain climbing rotation speed Nc, and the position determination threshold Nth is set (Equation (2)).

At time x23, when the mask time Xmc has elapsed from time x22, the holding process for the minimum sensor angle value θmin is started. That is, in order to mask the hold processing between time x22 and time x23, the minimum values MIN1 and MIN2 detected during this period are not held, but the minimum value MIN3 detected after the mask time Xmc has elapsed is held.

At time x24, the minimum value change amount Δθmin becomes smaller than the position determination threshold Nth, and at time x25, when the valley position determination time Xv has elapsed, the valley position determination flag Fvj is turned on. Then, the duty instruction value is set to 0 [%], and the power to the motor 40 is turned off.

In this embodiment, after the detent roller 26 falls to the bottom of the valley, the sensor angle θs is not updated to be greater than the backlash width, so the sensor angle θs is maintained at the maximum sensor angle value θmax or the minimum sensor angle value θmin with respect to the traveling direction. Then, it is determined that the detent roller 26 has fallen to the bottom of the valley. As a result, even if the sensor shaft vibrates even after the detent roller 26 has fallen into the trough due to relatively large play, for example, it can be appropriately determined that the detent roller 26 has fallen into the trough.

Immediately after the detent roller 26 reaches the troughs 211 and 212, the detent roller 26 may swing at the trough position and not stop. In this embodiment, in order to prevent the motor 40 from being de-energized while the detent roller 26 is swinging, the sensor angle maximum value θmax and the sensor angle A mask time Xmc is provided in which the minimum value θmin is not held. Further, by making the mask time Xmc variable according to environmental conditions, it is possible to more appropriately determine whether the detent roller 26 has fallen to the bottom of the valley.

As described above, the control device 60 controls switching of the detent mechanism 20 by driving the motor 40 in the park lock system 1 including the electric actuator 10 having the motor 40, the detent mechanism 20, and the position sensor 55. do.

The detent mechanism 20 includes a detent plate 21 and a detent roller 26. The detent plate 21 is formed with a plurality of troughs 211 and 212 and a peak 215 that separates the troughs 211 and 212. The detent roller 26 is movable between the troughs 211 and 212 by driving the output shaft 15 by the electric actuator 10 . The position sensor 55 can detect the position of the output shaft 15. Here, the position sensor 55 is not limited to one that directly detects the position of the output shaft 15, but also includes one that detects a detection target that can be converted by a shaft connected to the output shaft 15, a gear ratio, or the like.

The control unit 70 of the control device 60 includes a position determination unit 73 that determines that the detent roller 26 has fallen to the bottom of the target valley when moving the detent roller 26 to the target valley. "The detent roller has fallen to the bottom of the target valley" means that the swinging of the detent roller 26 has converged and is stopped at the bottom of the valley, regardless of the state of the sensor shaft.

The position determination unit 73 provides a mask time in which no position determination is performed after the load torque is reversed by the detent roller 26 overcoming the mountain portion 215, and after the mask time, position determination is performed using the detected value of the position sensor 55. I do. Thereby, it is possible to mask transient changes due to backlash reversal and perform position determination appropriately.

The position determination unit 73 determines whether the detent roller 26 falls to the bottom of the target trough based on the most advanced value, which is the detected value of the position sensor 55 when the detent roller 26 has advanced most in the traveling direction, according to the driving direction of the output shaft 15. determine what happened. In this embodiment, the target valley when switching from the P range to the notP range is the valley 212, and the most advanced value is the sensor angle maximum value θmax. Further, the target valley when switching from the notP range to the P range is the valley 211, and the most advanced value is the minimum sensor angle value θmin. Thereby, even if, for example, there is play between the detection portion of the position sensor 55 and the output shaft 15 and the detected value of the position sensor 55 fluctuates, the state of the detent roller 26 can be quickly determined.

The mask time Xmc is set according to the current applied to the motor 40 before the load torque is reversed. The mask time Xmc is set according to the voltage applied to the motor 40 before the load torque is reversed. Further, the mask time Xmc is set according to the temperature before the load torque is reversed. Furthermore, the mask time Xmc is set according to the sensor rotation speed Ns before the load torque is reversed. Thereby, the mask time Xmc can be appropriately set according to the environmental conditions.

Further, the mask time Xmc is set to a different value depending on the driving direction of the output shaft 15. Since the load torque differs depending on the driving direction, the mask time Xmc can be set more appropriately.

(Second embodiment)
The second embodiment is shown in FIGS. 15 to 17. This embodiment differs from the above embodiments in valley position determination processing, so this point will be mainly described. In this embodiment, the masking time is determined according to the amplitude after the detent roller 26 passes over the mountain.

The valley position determination process of this embodiment will be explained based on the flowcharts of FIGS. 15 and 16. The processing in S301 to S303 is similar to the processing in S201 to S203 in FIG. When it is determined that the angle change amount Δθ is greater than or equal to the sudden change determination threshold value θth (S303: YES), in S304, the position determination unit 73 turns on the mountain crossing determination flag Fmj and the mask flag Fmc. In this embodiment, while the mask flag Fmc is on, the maximum sensor angle value θmax or the minimum sensor angle value θmin is not held. The process in S305 is similar to the process in S205 in FIG.

In S306, which is proceeded to when it is determined that the mountain crossing determination flag Fmj is on (S302: YES), the position determination unit 73 determines whether the slope of the sensor angle θs has been reversed. If it is determined that the slope of the sensor angle θs is not reversed (S306: NO), the process moves to S310. If it is determined that the slope of the sensor angle θs has been reversed (S306: YES), the process moves to S307. In S307, the position determining unit 73 stores the sensor angle θs immediately before the reversal as the current value of the peak value.

In S308, the position determination unit 73 determines the vibration amplitude Δθp (see equation 3), which is the absolute value of the difference between the current value θp(n) and the previous value θp(n-1) of the peak value of the sensor angle θs. It is determined whether or not the threshold value Ath is less than or equal to the threshold value Ath. If it is determined that the vibration amplitude Δθp is larger than the vibration determination threshold Ath (S308: NO), the process moves to S310. If it is determined that the vibration amplitude Δθp is less than or equal to the vibration determination threshold Ath (S308: YES), the process moves to S309 and the mask flag Fmc is turned off.

Δθp=θp(n)-θp(n-1)...(3)

As shown in FIG. 16, in S310, the position determination unit 73 determines whether the mask flag Fmc is off. If it is determined that the mask flag Fmc is on (S310: NO), the process from S310 onward is skipped. If it is determined that the mask flag Fmc is off (S310: YES), the process moves to S311. The processing from S311 to S323 is similar to the processing from S209 to S221 in FIG. Further, the processes in S324 and S325 in FIG. 15 are similar to the processes in S222 and S223 in FIG. 8.

The valley position determination process of this embodiment will be explained based on the time chart of FIG. 17. Here, switching from the P range to the notP range will be explained as an example. In FIG. 17, the common time axis is the horizontal axis, and from the top, the target shift range, rotation angle, rotation speed, mountain crossing determination flag Fmj, vibration width Δθp, mask flag Fmc, sensor angle maximum value θmax, maximum value change amount Δθmax, It shows a valley position determination flag Fvj and a duty instruction value.

The processing from time x20 to time x22 is similar to the processing from time x10 to time x12 in FIG. Further, at time x22, when the angle change amount Δθ exceeds the sudden change determination threshold value θth and it is determined that the detent roller 26 has exceeded the mountain portion 215, the mask flag Fmc is turned on in addition to the mountain crossing determination flag Fmj.

When the mountain crossing determination flag Fmj is set at time x22, each time a reversal of the slope of the sensor angle θs is detected, the value immediately before the reversal is detected is stored as the peak value θp, and the vibration amplitude Δθp, which is the difference from the previous value, is stored. Calculate. In FIG. 17, to avoid complication, the vibration amplitudes on the sensor angle increasing side are written as Δθp1, Δθp2, Δθp3, and Δθp4 in order from time x22.

At time x23, when the vibration width Δθp3 becomes equal to or less than the vibration determination threshold Ath, the mask flag Fmc is turned off and the sensor angle maximum value θmax is held. At time x24, when the maximum value change Δθmax becomes smaller than the valley position determination threshold Nth, measurement of the determination standby time Xh is started, and at time x25, when the valley position determination time Xv has elapsed, the valley position determination flag Fvj is turned on. Make it. Then, the duty command value is set to 0 [%], and the power to the motor 40 is turned off.

In this embodiment, the position determination unit 73 determines that the mask time Xmc has elapsed when the vibration amplitude Δθp of the detected value of the position sensor 55 becomes equal to or less than the vibration determination threshold value Ath. In other words, the mask time Xmc is a period until the vibration width Δθp of the detected value of the position sensor 55 becomes equal to or less than the vibration determination threshold value Ath. Thereby, the mask time Xmc can be appropriately set according to the environmental conditions.

In the embodiment, the park lock system 1 is a "drive system," the electric actuator 10 is an "actuator," the detent plate 21 is a "detent member," the detent roller 26 is an "engaging member," and the motor 40 is a "drive source." The shaft 47 corresponds to a "shaft" and the control device 60 corresponds to an "actuator control device." Further, the sensor rotation speed Ns corresponds to the "drive change rate".

When switching from the P range to the notP range, the target valley is the valley 212, the most advanced value is the sensor angle maximum value θmax, and the amount of change in the most advanced value is the maximum value change amount Δθmax. Further, when switching from the notP range to the P range, the target valley is the valley 211, the most advanced value is the minimum sensor angle value θmin, and the amount of change in the most advanced value is the minimum value change amount Δθmin.

(Other embodiments)
In the above embodiment, the position determination threshold is made variable depending on the motor applied voltage, motor current, and load torque. In other embodiments, some of these may be omitted, or the position determination threshold may be changed using other parameters.

In the first embodiment, the mask time is made variable depending on the current, voltage, temperature, and drive change rate. In other embodiments, some of these may be omitted, or the mask time may be changed using other parameters.

In the above embodiment, the position determination threshold is set for each range change. In another embodiment, a position determination threshold is set at the first range change after a starting switch, such as a vehicle ignition switch, is turned on, and the initially set position is set until the starting switch is turned off. It is not necessary to set a position determination threshold every time the range is switched, such as by using a determination threshold. The same applies to the mask time.

In the embodiments described above, the speed reduction mechanism includes a worm gear, a helical gear, an intermediate gear, and the like. In other embodiments, the configuration of the speed reduction mechanism and the number of speed reduction stages may be different from those of the above embodiments. In the above embodiments, the drive source is a brushed DC motor. In other embodiments, the drive source may be a motor other than a brushed DC motor, a solenoid, or the like. In the above embodiments, the electric actuator is of a rotary type, but in other embodiments, it may be of a direct type.

In the above embodiments, the electric actuator is applied to a park lock system. In other embodiments, the electric actuator may be applied to in-vehicle systems other than the park lock system or drive systems other than the in-vehicle system.

The features of the present invention may be as follows, for example. 7. The actuator control device according to claim 1, wherein the mask time is set to different values depending on the driving direction of the output shaft.

The control unit and the method described in the present disclosure are implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. may be done. Alternatively, the controller and techniques described in this disclosure may be implemented by a dedicated computer provided by a processor configured with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be implemented using a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may be implemented by one or more dedicated computers configured. The computer program may also be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. As described above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention.

1...Park lock system (drive system)
10...Electric actuator (actuator)
15... Output shaft 20... Detent mechanism 21... Detent plate (detent member)
221, 222... Valley portion 215... Peak portion 26... Detent roller (engaging member)
40... Motor (drive source) 55... Position sensor 60... Control device (actuator control device)
73...Position determination section 74...Threshold value setting section

Claims (8)

an actuator (10) having a drive source (40);
A detent member (21) in which a plurality of troughs (211, 212) and a peak (215) separating the troughs are formed, and the trough is driven by the actuator to drive the output shaft (15). a detent mechanism (20) having an engagement member (26) movable between;
a position sensor (55) capable of detecting the position of the output shaft;
In a drive system (1) comprising: an actuator control device that controls switching of the detent mechanism by driving the actuator,
a position determination unit (73) that determines that the engagement member has fallen to the bottom of the target valley when moving the engagement member to the target valley;
The position determination unit provides a mask time in which position determination is not performed after the load torque is reversed by the engagement member overcoming the mountain portion, and after the mask time, the position determination unit uses the detection value of the position sensor. Actuator control device that determines position. The position determination unit is configured to determine whether the engagement member is at the bottom of the target trough based on a most advanced value that is a detected value of the position sensor when the output shaft has advanced most in the direction of travel according to the driving direction of the output shaft. The actuator control device according to claim 1, wherein the actuator control device determines that the actuator has fallen. The actuator control device according to claim 1 or 2, wherein the mask time is set according to the current applied to the actuator before load torque reversal. The actuator control device according to claim 1 or 2, wherein the mask time is set according to a voltage applied to the actuator before load torque reversal. The actuator control device according to claim 1 or 2, wherein the mask time is set according to a temperature before load torque reversal. The actuator control device according to claim 1 or 2, wherein the mask time is set according to a drive change rate of the output shaft before the load torque is reversed. The actuator control device according to claim 1 or 2, wherein the position determination unit determines that the mask time has elapsed when the vibration width of the detected value of the position sensor becomes equal to or less than a vibration determination threshold. The actuator control device according to claim 1 or 2, wherein the mask time is set to a different value depending on the driving direction of the output shaft.

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