Control device and electric actuator

Abstract

Control device and electric actuator. The control device is provided in the electric actuator, and the electric actuator is mounted on a vehicle and has a motor unit, a transmission mechanism unit that transmits the rotation of the motor unit to the output shaft, a first rotation sensor that detects the rotation of the motor unit, and a second rotation sensor that detects the rotation of the output shaft. The control device controls the motor unit based on the rotation angle of the output shaft according to the shift operation of the vehicle. The control device includes: a rotation angle calculation unit that can calculate the rotation angle of the output shaft based on the detection result of the second rotation sensor; and a storage unit that stores deviation-related information between the rotation of the motor unit and the rotation of the output shaft when there are at least two or more operation patterns in which the combinations of the last performed shift operation and the currently performed shift operation are different. When the second rotation sensor fails, the rotation angle calculation unit calculates the rotation angle of the output shaft based on the detection result of the first rotation sensor and the deviation-related information.

Description

Technical Field

[0001] The present invention relates to a control device and an electric actuator. Background Art

[0002] There is known an electric actuator having a motor unit and a transmission mechanism unit that transmits the rotation of the motor unit to an output shaft. For example, in Patent Document 1, a rotary actuator is described as such an electric actuator, and this rotary actuator is used as a drive unit of a by-wire shift system that switches gears of an automatic transmission of a vehicle.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-247798

[0004] In the electric actuator as described above, the motor unit is sometimes controlled based on the detection result of a rotation sensor capable of detecting the rotation angle of the output shaft to control the rotation angle of the output shaft. However, in this case, when the rotation sensor capable of detecting the rotation angle of the output shaft malfunctions, the control accuracy of the rotation angle of the output shaft may decrease. Summary of the Invention

[0005] In view of the above circumstances, one object of the present invention is to provide a control device that can suppress a decrease in the control accuracy of the rotation angle of an output shaft even when a rotation sensor capable of detecting the rotation angle of the output shaft malfunctions, and an electric actuator including such a control device.

[0006] A control device according to one aspect of the present invention is provided in an electric actuator that is mounted on a vehicle and has a motor unit, a transmission mechanism unit that transmits the rotation of the motor unit to an output shaft, a first rotation sensor capable of detecting the rotation of the motor unit, and a second rotation sensor capable of detecting the rotation of the output shaft. The control device controls the motor unit based on the rotation angle of the output shaft according to a shift operation of the vehicle. The control device includes: a rotation angle calculation unit that can calculate the rotation angle of the output shaft based on the detection result of the second rotation sensor; and a storage unit that stores deviation-related information between the rotation of the motor unit and the rotation of the output shaft in cases where at least two or more operation patterns in which combinations of the previous shift operation and the current shift operation are different from each other are performed. The rotation angle calculation unit calculates the rotation angle of the output shaft based on the detection result of the first rotation sensor and the deviation-related information when the second rotation sensor malfunctions.

[0007] One aspect of the electric actuator of the present invention is mounted on a vehicle. The electric actuator includes: a motor unit; a transmission mechanism unit that transmits the rotation of the motor unit to an output shaft; a first rotation sensor that can detect the rotation of the motor unit; a second rotation sensor that can detect the rotation of the output shaft; and the above control device.

[0008] According to one aspect of the present invention, in an electric actuator, even when a rotation sensor capable of detecting the rotation angle of the output shaft fails, it is possible to suppress a decrease in the control accuracy of the rotation angle of the output shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram showing an actuator device equipped with the electric actuator of the present embodiment, and shows a case where the locking gear is in a non-locked state.

[0010] Figure 2 It is a diagram showing an actuator device equipped with the electric actuator of the present embodiment, and shows a case where the locking gear is in a locked state.

[0011] Figure 3 It is a diagram showing a part of the actuator device equipped with the electric actuator of the present embodiment as viewed from above.

[0012] Figure 4 It is a block diagram showing the functional structure of the electric actuator of the present embodiment.

[0013] Figure 5 It is a diagram showing an example of the idling angle of the motor unit stored in the storage unit in the present embodiment.

[0014] Figure 6 It is a flowchart showing an example of the control process of the electric actuator of the present embodiment.

[0015] REFERENCE SIGNS

[0016] 10: Electric actuator; 20: Motor unit; 30: Transmission mechanism unit; 40: Control device; 48: Rotation angle calculation unit; 50: Storage unit; 51: First rotation sensor; 52: Second rotation sensor; 60: Output shaft; 90: Information acquisition unit; G1, G2, G3, G4, G5, G6, G7, G8, G9, G10: Groups. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] In each figure, the Z-axis direction is the up-down direction with the positive side as the upper side and the negative side as the lower side. For example, the axial direction of the central axis J, which is an imaginary axis appropriately shown in each figure, is parallel to the Z-axis direction, i.e., the up-down direction. In the following description, the direction parallel to the axial direction of the central axis J is simply referred to as "axial direction Z". Additionally, unless otherwise specified, the radial direction centered on the central axis J is simply referred to as "radial direction". Further, the direction of counterclockwise rotation centered on the central axis J when viewed from the upper side is referred to as "first rotation direction θ1", and the direction of clockwise rotation centered on the central axis J when viewed from the upper side is referred to as "second rotation direction θ2".

[0018] Moreover, in each figure, the X-axis direction is the direction perpendicular to the Z-axis direction, and the Y-axis direction is the direction perpendicular to both the X-axis direction and the Z-axis direction. The direction parallel to the X-axis direction is referred to as "front-back direction X", and the direction parallel to the Y-axis direction is referred to as "left-right direction Y". In the front-back direction X, the positive side (+X side) of the X-axis direction is set as the front side, and the negative side (-X side) of the X-axis direction is set as the rear side. In the left-right direction Y, the positive side (+Y side) of the Y-axis direction is set as the left side, and the negative side (-Y side) of the Y-axis direction is set as the right side.

[0019] Furthermore, "up-down direction", "front-back direction", "left-right direction", "upper side", "lower side", "front side", "rear side", "left side", and "right side" are merely names used to describe the relative positional relationship of each part, and the actual configuration relationship, etc. can also be a configuration relationship other than the configuration relationship indicated by these names, etc.

[0020] As Figure 1 and Figure 2 shown, the electric actuator 10 of the present embodiment is mounted on the actuator device 1. The actuator device 1 is, for example, provided in a vehicle and is a by-wire shift type actuator device that is driven based on the driver's shift operation. The actuator device 1 moves the manual valve 72 based on the driver's shift operation and switches the hydraulic circuit in the oil passage body 80. Thereby, the actuator device 1 can switch the gears of the vehicle, for example, between the parking gear P, reverse gear R, neutral gear N, and drive gear D.

[0021] In addition, the actuator device 1 switches the locking gear G between the locked state and the unlocked state based on the driver's shift operation. The actuator device 1 sets the locking gear G in the locked state when the gear of the vehicle is in the parking gear P, and sets the locking gear G in the unlocked state when the gear of the vehicle is in a gear other than the parking gear P. The locking gear G is a gear connected to the axle. The locking gear G has a plurality of tooth portions Ga on its outer peripheral surface and rotates around a rotation axis Gj extending in the left-right direction Y.

[0022] The actuator device 1 includes an electric actuator 10, an output shaft 60, an oil passage body 80, an arm operation part 61, a valve operation part 62, a locking arm 71, and a manual valve 72. The output shaft 60 is, for example, cylindrical and extends in the axial direction Z with the central axis J as the center. The output shaft 60 rotates about the central axis J by means of the electric actuator 10.

[0023] The oil passage body 80 has a hydraulic circuit formed by a plurality of oil passages inside. As Figure 3 shown, the oil passage main body 80 has an insertion hole 81 that is recessed in the left - right direction Y. Although not shown in the figure, the insertion hole 81 is connected to the oil passages inside the oil passage main body 80. The manual valve 72 is arranged in the insertion hole 81 so as to be movable in the left - right direction Y. The manual valve 72 is, for example, rod - shaped and extends in the left - right direction Y. By moving the manual valve 72 in the left - right direction Y, the connection between the oil passages in the oil passage body 80 changes, and the hydraulic circuit is switched.

[0024] As Figure 1 and Figure 2 shown, the arm operation part 61 has a connecting part 61a, a rod 61b, a support part 61c, a flange part 61e, and a helical spring 61f. The connecting part 61a is fixed to the output shaft 60. The connecting part 61a projects radially outward from the output shaft 60, for example. The rod 61b is arranged to be movable in the front - rear direction X. The rear end of the rod 61b, for example, is connected to the connecting part 61a.

[0025] The support part 61c is frustum - shaped with an axis extending in the front - rear direction X. The outer diameter of the support part 61c increases from the front side to the rear side. The support part 61c has a through - hole 61d that penetrates the support part 61c in the front - rear direction X. The front end of the rod 61b passes through the through - hole 61d. The support part 61c can move relative to the rod 61b in the front - rear direction X. The support part 61c and the rod 61b are, for example, concentrically arranged. The flange part 61e is fixed to the rod 61b at a position rearward of the support part 61c.

[0026] The helical spring 61f extends in the front - rear direction X. The helical spring 61f is arranged between the support part 61c and the flange part 61e in the front - rear direction X. The rod 61b passes through the inside of the helical spring 61f. The rear end of the helical spring 61f contacts the flange part 61e. The front end of the helical spring 61f contacts the support part 61c. The helical spring 61f expands and contracts as the support part 61c moves relative to the rod 61b in the front - rear direction X, and applies an elastic force in the front - rear direction X to the support part 61c.

[0027] The valve operation part 62 is, for example, fixed to the lower end part of the output shaft 60. As Figure 3 shown, the valve operation part 62 projects radially outward from the output shaft 60, for example. The front end part of the valve operation part 62 is connected to the manual valve 72.

[0028] The arm operation part 61 and the valve operation part 62 are driven by the electric actuator 10. Specifically, when the output shaft 60 is rotated about the central axis J by the electric actuator 10, the connecting part 61a and the valve operation part 62 are also rotated about the central axis J along with the rotation of the output shaft 60. The rod 61b moves in the front-rear direction X as the connecting part 61a rotates about the central axis J. For example, the rod 61b moves rearward when the connecting part 61a rotates in the first rotation direction θ1. The rod 61b moves forward when the connecting part 61a rotates in the second rotation direction θ2. Along with the movement of the rod 61b in the front-rear direction X, the support part 61c, the flange part 61e, and the coil spring 61f also move in the front-rear direction X.

[0029] The electric actuator 10 can switch the position of the valve operation part 62 between the parking position PP and the non-parking position based on the driver's shift operation. The non-parking position is a position other than the parking position PP. In the present embodiment, as Figure 3 shown, the non-parking position includes the drive position DP, the neutral position NP, and the reverse position RP. That is, in the present embodiment, the electric actuator 10 switches the position of the valve operation part 62 between the drive position DP, the neutral position NP, the reverse position RP, and the parking position PP based on the driver's shift operation. In the present embodiment, the parking position PP is a locked position where the locking gear G is in a locked state, and the non-parking position is a non-locked position where the locking gear G is in a non-locked state.

[0030] The drive position DP is the position of the valve operation part 62 when the vehicle's gear is in the drive gear D. The neutral position NP is the position of the valve operation part 62 when the vehicle's gear is in the neutral gear N. The reverse position RP is the position of the valve operation part 62 when the vehicle's gear is in the reverse gear R. The parking position PP is the position of the valve operation part 62 when the vehicle's gear is in the parking gear P. Figure 1 The case where the valve operation part 62 is located in the reverse position RP in the non-parking position is shown, for example. Figure 2 The case where the valve operation part 62 is located in the parking position PP is shown, for example.

[0031] As Figure 3As shown, in the parking position PP, when viewed from above, the valve operating portion 62 is arranged along an imaginary line LP that is inclined toward the second rotation direction θ2 side with respect to the front-rear direction X. Although not shown, in the reverse position RP, when viewed from above, the valve operating portion 62 is arranged along an imaginary line LR that extends in the front-rear direction X. In the neutral position NP, when viewed from above, the valve operating portion 62 is arranged along an imaginary line LN that is inclined toward the first rotation direction θ1 side with respect to the front-rear direction X. In the drive position DP, when viewed from above, the valve operating portion 62 is arranged along an imaginary line LD that is inclined toward the first rotation direction θ1 side with respect to the front-rear direction X more than the imaginary line LN.

[0032] The position of the front end portion of the valve operating portion 62 in the left-right direction Y is, for example, from the left side to the right side in the order of the parking position PP, the reverse position RP, the neutral position NP, and the drive position DP. As the position of the front end portion of the valve operating portion 62 changes in the left-right direction Y, the position of the manual valve 72 connected to the front end portion of the valve operating portion 62 changes in the left-right direction Y. That is, the position of the manual valve 72 in the left-right direction Y is from the left side to the right side in the order of the parking position PP, the reverse position RP, the neutral position NP, and the drive position DP. In this way, the valve operating portion 62 moves the manual valve 72.

[0033] As Figure 1 and Figure 2 shown, the locking arm 71 is arranged, for example, on the front side of the arm operating portion 61. The locking arm 71 is arranged to be rotatable about a rotation axis 71d. The rotation axis 71d is an axis that extends in the left-right direction Y. The locking arm 71 has a first portion 71a and a second portion 71b. The first portion 71a extends rearward from the rotation axis 71d. The rear end of the first portion 71a contacts the outer peripheral surface of the support portion 61c. The second portion 71b extends from the rotation axis 71d upward and slightly forwardly inclined. The second portion 71b has an engaging portion 71c that protrudes forward at the upper end.

[0034] The locking arm 71 rotates about the rotation axis 71d as the lever 61b and the support portion 61c move in the front-rear direction X. For example, when the output shaft 60 rotates in the second rotation direction θ2 from the Figure 1 state shown, the lever 61b and the support portion 61c move forward. Since the outer diameter of the support portion 61c increases from the front side to the rear side, when the support portion 61c moves forward, the first portion 71a in contact with the support portion 61c is lifted upward, and the locking arm 71 rotates counterclockwise when viewed from the left about the rotation axis 71d. As a result, the engaging portion 71c approaches the locking gear G and meshes between the tooth portions Ga as Figure 2 shown.

[0035] At this time, depending on the position of the tooth portion Ga, the following situation exists: the engaging portion 71c comes into contact with the tooth portion Ga, and the locking arm 71 cannot rotate to a position where the engaging portion 71c engages between the tooth portions Ga. Even in such a case, in the present embodiment, since the support portion 61c can move in the front-rear direction X with respect to the lever 61b, it is also possible to allow the lever 61b to move to the parking position PP and the support portion 61c to be in a state located rearward of the parking position PP. Thereby, rotation of the output shaft 60 can be suppressed from being obstructed, and a load applied to the electric actuator 10 can be suppressed.

[0036] In addition, in a state where the lever 61b is in the parking position PP and the support portion 61c is located rearward of the parking position PP, the coil spring 61f is in a state of being compressed and deformed. Therefore, an elastic force acting forward is applied to the support portion 61c by the coil spring 61f. Thereby, a rotational torque in a direction of rotating counterclockwise when viewed from the left around the rotation axis 71d is applied to the locking arm 71 from the coil spring 61f via the support portion 61c. Therefore, when the locking gear G rotates and the position of the tooth portion Ga shifts, the locking arm 71 rotates and the engaging portion 71c engages between the tooth portions Ga.

[0037] On the other hand, for example, when the output shaft 60 rotates in the first rotation direction θ1 from the Figure 2 state shown, the lever 61b and the support portion 61c move rearward. When the support portion 61c moves rearward, the first portion 71a lifted by the support portion 61c moves downward due to its own weight or a force from the locking gear G, and the locking arm 71 rotates clockwise when viewed from the left around the rotation axis 71d. Thereby, the engaging portion 71c separates from the locking gear G and disengages from between the tooth portions Ga as shown in Figure 1 .

[0038] As Figure 4 shown, the electric actuator 10 includes a motor unit 20, a transmission mechanism unit 30, a first rotation sensor 51, a second rotation sensor 52, and a control device 40. The transmission mechanism unit 30 transmits the rotation of the motor unit 20 to the output shaft 60. For example, a shaft of an unillustrated rotor of the motor unit 20 is connected to the transmission mechanism unit 30. In the present embodiment, the transmission mechanism unit 30 is a speed reducer.

[0039] In addition, in the present specification, the rotation of the motor unit 20 refers to the rotation of an unillustrated rotor of the motor unit 20. In addition, in the present specification, the rotation angle of the motor unit 20 refers to the rotation angle of an unillustrated rotor of the motor unit 20, and the rotational angular velocity of the motor unit 20 refers to the rotational angular velocity of an unillustrated rotor of the motor unit 20.

[0040] The first rotation sensor 51 is a sensor capable of detecting the rotation of the motor unit 20. More specifically, the first rotation sensor 51 can detect the rotation of a shaft (not shown) of the motor unit 20, for example. The first rotation sensor 51 detects the rotation of the motor unit 20 at a prescribed interval. The first rotation sensor 51 is, for example, a magnetic sensor. The first rotation sensor 51 is, for example, a Hall element such as a Hall IC.

[0041] The second rotation sensor 52 is a sensor capable of detecting the rotation of the output shaft 60. The second rotation sensor 52 detects the rotation of the output shaft 60 at a prescribed interval. The interval at which the second rotation sensor 52 detects the rotation of the output shaft 60 is, for example, greater than the interval at which the first rotation sensor 51 detects the rotation of the motor unit 20. The second rotation sensor 52 is, for example, a magnetic sensor. The second rotation sensor 52 is, for example, a Hall element such as a Hall IC.

[0042] The control device 40 is provided in the electric actuator 10 mounted on a vehicle, and is a control device that controls the motor unit 20 based on the rotation angle of the output shaft 60 according to the shift operation of the vehicle. In the present embodiment, the control device 40 is mounted on the vehicle and controls the motor unit 20 based on the shift operation of the vehicle. The control device 40 includes a rotation angle command unit 41, a rotation angle control unit 42, a rotation angular velocity control unit 43, a current control unit 44, an inverter unit 45, a current detection unit 46, a rotation angular velocity calculation unit 47, a rotation angle calculation unit 48, a failure detection unit 49, a storage unit 50, and an information acquisition unit 90. In addition, regarding each part of the control device 40 shown as functional blocks in Figure 4 as long as the control device 40 can have the functions of each part, the control device 40 can be configured in any manner.

[0043] A movement command CS is input to the rotation angle command unit 41. The movement command CS is a signal sent to the electric actuator 10 by performing a shift operation of the vehicle. The movement command CS is sent from, for example, the engine control unit of the vehicle. Information regarding which gear of the vehicle is to be switched is included in the movement command CS. The rotation angle command unit 41 outputs a target angle command 41a to the rotation angle control unit 42 according to the movement command CS. The target angle command 41a includes the target rotation angle of the output shaft 60.

[0044] The rotation angle control unit 42 outputs an angular velocity command 42a to the rotational angular velocity control unit 43 according to the input target angle command 41a. The rotational angular velocity control unit 43 outputs a current command 43a to the current control unit 44 according to the input angular velocity command 42a. The current control unit 44 sends a signal to the inverter unit 45 according to the current command 43a. Current is supplied to the inverter unit 45 from the outside of the electric actuator 10. The inverter unit 45 converts the frequency of the current supplied from the outside according to the signal from the current command 43a. The inverter unit 45 supplies the current with the converted frequency to the motor unit 20. The current detection unit 46 detects the current output from the inverter unit 45 to the motor unit 20. The detection result of the current detection unit 46 is input to the current control unit 44.

[0045] A signal from the first rotation sensor 51 is input to the rotational angular velocity calculation unit 47. The rotational angular velocity calculation unit 47 can calculate the rotational angular velocity of the motor unit 20 according to the detection result of the first rotation sensor 51. The rotational angular velocity calculation unit 47 calculates the rotational angular velocity of the motor unit 20 according to the difference between the detection result of the first rotation sensor 51 detected at the first timing and the detection result of the first rotation sensor 51 detected at the second timing following the first timing. By using the rotational angular velocity of the motor unit 20 calculated in this way, the rotation of the motor unit 20 can be appropriately controlled. The rotational angular velocity of the motor unit 20 calculated in the rotational angular velocity calculation unit 47 is input to the rotational angular velocity control unit 43.

[0046] A signal from the second rotation sensor 52 is input to the rotation angle calculation unit 48. The rotation angle calculation unit 48 can calculate the rotation angle of the output shaft 60 according to the detection result of the second rotation sensor 52. The rotation angle of the output shaft 60 calculated in the rotation angle calculation unit 48 is output to the rotation angle control unit 42. In the present embodiment, a signal from the first rotation sensor 51 is also input to the rotation angle calculation unit 48. In the present embodiment, the rotation angle calculation unit 48 can calculate the rotation angle of the motor unit 20 according to the detection result of the first rotation sensor 51.

[0047] A signal from the second rotation sensor 52 is input to the failure detection unit 49. The failure detection unit 49 can detect whether a failure has occurred in the second rotation sensor 52 based on the detection result of the second rotation sensor 52. For example, when an incorrect signal is input from the second rotation sensor 52 or the value of the signal input from the second rotation sensor 52 is inaccurate, the failure detection unit 49 determines that a failure has occurred in the second rotation sensor 52. The case where the value of the signal input from the second rotation sensor 52 is inaccurate includes, for example, the case where the value of the signal input from the second rotation sensor 52 deviates from the value of the signal input from the second rotation sensor 52 last time by more than a specified value. The detection result of the failure detection unit 49 is input to the rotation angle calculation unit 48.

[0048] In the storage unit 50, deviation-related information between the rotation of the motor unit 20 and the rotation of the output shaft 60 is stored in the case where there are at least two or more operation patterns in which the combinations of the vehicle shift operations performed last time and the vehicle shift operations performed this time are different from each other. The vehicle shift operation is an operation performed by a driver or the like to change the gears of the vehicle from a certain state to a different state. In the present embodiment, the vehicle shift operation is an operation performed to change the gears of the vehicle from any one state among the parking gear P, reverse gear R, neutral gear N, and forward gear D to another state. In this specification, an "operation pattern" is a pattern constituted by the combination of the vehicle shift operation performed last time and the vehicle shift operation performed this time.

[0049] The deviation-related information between the rotation of the motor unit 20 and the rotation of the output shaft 60 includes the deviation amount between the rotation of the motor unit 20 and the rotation of the output shaft 60, data capable of calculating the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60, and the like. The data capable of calculating the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 includes the detection result of the first rotation sensor 51, the detection result of the second rotation sensor 52, the assembly error of the electric actuator 10, the error of the reduction ratio of the transmission mechanism unit 30, and the like.

[0050] The deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 is generated, for example, due to the loosening of the connection between the motor unit 20 and the transmission mechanism unit 30. In the present embodiment, the deviation-related information between the rotation of the motor unit 20 and the rotation of the output shaft 60 includes the idling angle of the motor unit 20. The idling angle is the change amount of the rotation angle of the motor unit 20 from the start of rotation of the motor unit 20 to the start of rotation of the output shaft 60. In other words, the idling angle is the angle at which the motor unit 20 idles during the period from the start of rotation of the motor unit 20 to the start of rotation of the output shaft 60. In addition, in the following description, the deviation-related information between the rotation of the motor unit 20 and the rotation of the output shaft 60 is simply referred to as "deviation-related information".

[0051] In the present embodiment, deviation-related information for each of the operation patterns of all combinations of the previous shift operation and the current shift operation is stored in the storage unit 50. Specifically, for example, deviation-related information for each of the all 36 operation patterns shown in Figure 5 is stored in the storage unit 50. In the present embodiment, deviation-related information for each operation pattern is stored in the storage unit 50 in advance.

[0052] In Figure 5 , the idling angle [°] of the motor unit 20 is shown as the deviation-related information. In Figure 5 , "P" represents the parking gear P, "R" represents the reverse gear R, "N" represents the neutral gear N, and "D" represents the drive gear D. In the previous shift operation and the current shift operation, the arrows between the symbols "P", "R", "N", and "D" indicate the direction of gear change of the vehicle during the shift operation. For example, "P→R" represents a shift operation of changing the gear of the vehicle from the parking gear P to the reverse gear R. For example, "P←R" represents a shift operation of changing the gear of the vehicle from the reverse gear R to the parking gear P. In addition, Figure 5 the direction of the arrow in Figure 3 is shown corresponding to the direction of movement of the manual valve 72 shown in

[0053] In Figure 5 , for example, the value recorded in the column where the previous shift operation is "P→R" and the current shift operation is "P←R" represents the idling angle [°] of the motor unit 20 when, after performing a shift operation of changing the gear of the vehicle from the parking gear P to the reverse gear R, a shift operation of changing the gear of the vehicle from the reverse gear R to the parking gear P is performed.

[0054] In Figure 5 , it is shown that when the idling angle is positive, the idling direction of the motor unit 20 is the direction in which the motor unit 20 rotates when the output shaft 60 rotates in the first rotation direction θ1. It is shown that when the idling angle is negative, the idling direction of the motor unit 20 is the direction in which the motor unit 20 rotates when the output shaft 60 rotates in the second rotation direction θ2.

[0055] As Figure 5 shows, there is a case where the idling angle of the motor unit 20 during the current shift operation varies depending on what the previous shift operation was. That is, there is a case where even if the current shift operation is the same shift operation, the idling angle during the current shift operation is different when the previous shift operation is different. In Figure 5In the example, when the direction of rotation of the motor unit 20 during the current shift operation is the same as the direction of rotation of the motor unit 20 during the previous shift operation, the idling angle of the motor unit 20 is relatively small. In other words, in Figure 5 In the example, when the direction of movement of the manual valve 72 during the current shift operation is the same as the direction of movement of the manual valve 72 during the previous shift operation, the idling angle of the motor unit 20 is relatively small.

[0056] On the other hand, in Figure 5 In the example, when the direction of rotation of the motor unit 20 during the current shift operation is the opposite of the direction of rotation of the motor unit 20 during the previous shift operation, the idling angle of the motor unit 20 is relatively large. In other words, in Figure 5 In the example, when the direction of movement of the manual valve 72 during the current shift operation is the opposite of the direction of movement of the manual valve 72 during the previous shift operation, the idling angle of the motor unit 20 is relatively large.

[0057] In addition, the magnitude relationship of the idling angle of the motor unit 20 is not limited to the above Figure 5 example. For example, there are also cases where: when the direction of rotation of the motor unit 20 during the current shift operation is the same as the direction of rotation of the motor unit 20 during the previous shift operation, the idling angle of the motor unit 20 is relatively large. In addition, for example, there are also cases where: when the direction of rotation of the motor unit 20 during the current shift operation is the opposite of the direction of rotation of the motor unit 20 during the previous shift operation, the idling angle of the motor unit 20 is relatively small. The magnitude relationship of the idling angle of the motor unit 20 may change, for example, due to the magnitude of the braking force applied to the output shaft 60 by the motor unit 20 when the motor unit 20 stops rotating.

[0058] Information related to the previous shift operation is stored in the storage unit 50. Stored in the storage unit 50 is, for example, which state of the vehicle's gears (parking gear P, reverse gear R, neutral gear N, drive gear D) was changed to which state during the previous shift operation. For example, every time a new shift operation is performed, the information related to the previous shift operation stored in the storage unit 50 is overwritten.

[0059] As Figure 4As shown, a signal from the first rotation sensor 51 and a signal from the second rotation sensor 52 are input to the information acquisition unit 90. The information acquisition unit 90 can acquire deviation-related information based on the detection results of the first rotation sensor 51 and the second rotation sensor 52. In the present embodiment, the information acquisition unit 90 can calculate the idling angle of the motor unit 20 based on the detection results of the first rotation sensor 51 and the second rotation sensor 52. Specifically, for example, the information acquisition unit 90 calculates the rotation angle that the motor unit 20 rotates during the period from the start of rotation of the motor unit 20 to the start of rotation of the output shaft 60 as the idling angle based on the signal input from the first rotation sensor 51 and the signal input from the second rotation sensor 52.

[0060] In the present embodiment, the information acquisition unit 90 discriminates the operation pattern based on the information related to the previous shift operation stored in the storage unit 50, and causes the storage unit 50 to store the acquired deviation-related information as the deviation-related information for the discriminated operation pattern. At this time, when the deviation-related information for the executed operation pattern is already stored in the storage unit 50, the deviation-related information for this operation pattern is overwritten. That is, in the present embodiment, when an operation pattern for which the deviation-related information is already stored in the storage unit 50 is performed, the information acquisition unit 90 updates the deviation-related information for the operation pattern stored in the storage unit 50.

[0061] The control device 40 controls the motor unit 20 according to, for example, Figure 6 the flowchart shown. After starting the control of the motor unit 20 based on the shift operation performed this time (step S1), the control device 40 determines whether the second rotation sensor 52 is operating normally (step S2). In the present embodiment, the control device 40 determines whether the second rotation sensor 52 has failed through the failure detection unit 49, and determines whether the second rotation sensor 52 is operating normally. When the failure detection unit 49 determines that the second rotation sensor 52 has not failed, the control device 40 determines that the second rotation sensor 52 is operating normally. On the other hand, when the failure detection unit 49 determines that the second rotation sensor 52 has failed, the control device 40 determines that the second rotation sensor 52 is not operating normally.

[0062] When it is determined that the second rotation sensor 52 is operating normally (step S2: YES), the control device 40 calculates the rotation angle of the output shaft 60 based on the detection result of the second rotation sensor 52 (step S3a). Specifically, the control device 40 acquires the rotation angle of the output shaft 60 through the rotation angle calculation unit 48. The control device 40 rotates the motor unit 20 based on the rotation angle of the output shaft 60 (step S4a).

[0063] After starting the rotation of the motor unit 20, the control device 40 determines whether the output shaft 60 has started to rotate (step S5). In the present embodiment, the control device 40 determines whether the output shaft 60 has started to rotate in the information acquisition unit 90. The information acquisition unit 90 determines that the output shaft 60 has started to rotate, for example, when the signal input from the second rotation sensor 52 has changed. The case where the signal from the second rotation sensor 52 has changed is, for example, the case where the voltage value of the signal input from the second rotation sensor 52 to the information acquisition unit 90 exceeds a specified threshold value, etc.

[0064] When it is determined that the output shaft 60 has started to rotate (step S5: YES), the control device 40 causes the storage unit 50 to store the idling angle of the motor unit 20 (step S6). Specifically, in the present embodiment, the control device 40 causes the storage unit 50 to store the rotation angle of the motor unit 20 from the start of rotation of the motor unit 20 to the start of rotation of the output shaft 60 as the idling angle through the information acquisition unit 90. At this time, in the present embodiment, since the idling angle of the motor unit 20 is stored in the storage unit 50 in advance for each operation pattern, the information acquisition unit 90 overwrites the idling angle corresponding to the discriminated operation pattern. In addition, step S6 is executed, for example, once every time a shift operation is performed.

[0065] After the output shaft 60 starts to rotate, the control device 40 also continues to rotate the motor unit 20, and determines whether the rotation angle of the output shaft 60 has reached the target rotation angle (step S7). When it is determined that the rotation angle of the output shaft 60 has not reached the target rotation angle (step S7: NO), the control device 40 determines, for example, whether the second rotation sensor 52 is operating normally (step S2), and continues the control of the motor unit 20. When it is determined that the rotation angle of the output shaft 60 has reached the target rotation angle (step S7: YES), the control device 40 stops the control of the motor unit 20 (step S8).

[0066] On the other hand, when it is determined in step S2 that the second rotation sensor 52 is not operating normally (step S2: NO), the control device 40 calculates the rotation angle of the output shaft 60 based on the detection result of the first rotation sensor 51 and the idling angle of the motor unit 20 stored in the storage unit 50 (step S3b). In the present embodiment, the control device 40 calculates the rotation angle of the output shaft 60 based on the detection result of the first rotation sensor 51 and the idling angle of the motor unit 20 in the rotation angle calculation unit 48. That is, in the present embodiment, when the second rotation sensor 52 fails, the rotation angle calculation unit 48 calculates the rotation angle of the output shaft 60 based on the detection result of the first rotation sensor 51 and the deviation-related information.

[0067] Specifically, the rotation angle calculation unit 48 calculates the rotation angle of the output shaft 60, for example, by dividing the value obtained by subtracting the idling angle from the rotation angle of the motor unit 20 calculated based on the detection result of the first rotation sensor 51 by the reduction ratio of the transmission mechanism unit 30 serving as a speed reducer. The control device 40 rotates the motor unit 20 based on the calculated rotation angle of the output shaft 60 (step S4b). Then, similarly to the case where the second rotation sensor 52 is normal, the control device 40 performs steps S7 and S8.

[0068] As described above, for example, there may be looseness in the connection between the motor unit 20 and the transmission mechanism unit 30, resulting in a deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60. Therefore, for example, when calculating the rotation angle of the output shaft 60 only based on the rotation angle of the motor unit 20 detected by the first rotation sensor 51, the calculated rotation angle of the output shaft 60 may deviate significantly from the actual rotation angle of the output shaft 60.

[0069] In contrast, according to the present embodiment, when the second rotation sensor 52 fails, the rotation angle calculation unit 48 calculates the rotation angle of the output shaft 60 based on the detection result of the first rotation sensor 51 and information related to the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60. Therefore, the calculated rotation angle of the output shaft 60 can be corrected based on the deviation-related information. Thus, compared with the case of calculating the rotation angle of the output shaft 60 only based on the detection result of the first rotation sensor 51, the rotation angle of the output shaft 60 can be calculated with high precision.

[0070] Here, there is a case where the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 varies depending on the operation pattern performed. Therefore, if only the information related to the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 is stored in the storage unit 50, it may not be possible to calculate the rotation angle of the output shaft 60 with high precision when the operation patterns are different.

[0071] In contrast, according to the present embodiment, the deviation-related information stored in the storage unit 50 includes deviation-related information in the case of at least two or more operation patterns in which the combinations of the last performed shift operation and the currently performed shift operation are different from each other. That is, deviation-related information corresponding to two or more operation patterns is stored in the storage unit 50. Therefore, the calculated rotation angle of the output shaft 60 can be appropriately corrected based on the operation pattern executed. Thus, the rotation angle of the output shaft 60 can be calculated with higher precision.

[0072] From the above, according to this embodiment, even when the second rotation sensor 52 that can detect the rotation angle of the output shaft 60 malfunctions, it is possible to suppress a decrease in the control accuracy of the rotation angle of the output shaft 60. Therefore, even when the second rotation sensor 52 malfunctions, the control device 40 can appropriately control the motor unit 20 based on the shift operation of the vehicle. Thus, even when the second rotation sensor 52 malfunctions, it is possible to appropriately switch the gears of the vehicle between the parking gear P, reverse gear R, neutral gear N, and drive gear D using the electric actuator 10.

[0073] Specifically, in this embodiment, when the second rotation sensor 52 malfunctions, the rotation angle calculation unit 48 calculates the rotation angle of the output shaft 60 based on the rotation angle of the motor unit 20, the idling angle of the motor unit 20 stored in the storage unit 50, and the reduction ratio of the transmission mechanism unit 30 as a speed reducer. Therefore, for example, by dividing the angle obtained by subtracting the idling angle from the rotation angle of the motor unit 20 by the reduction ratio, the rotation angle of the output shaft 60 can be appropriately calculated.

[0074] In addition, according to this embodiment, there is also an information acquisition unit 90 that can acquire deviation-related information based on the detection results of the first rotation sensor 51 and the second rotation sensor 52. The information acquisition unit 90 discriminates the operation pattern based on the information related to the last shift operation stored in the storage unit 50, and stores the acquired deviation-related information as the deviation-related information for the discriminated operation pattern in the storage unit 50. Therefore, for example, even without previously storing the deviation-related information in the storage unit 50, it is possible to use the information acquisition unit 90 to make the storage unit 50 learn the deviation-related information. In addition, for example, before using the electric actuator 10, it is also possible to perform control of the motor unit 20 corresponding to all operation patterns and make the storage unit 50 store the deviation-related information corresponding to all operation patterns.

[0075] In addition, according to this embodiment, when an operation pattern for which deviation-related information is stored in the storage unit 50 is performed, the information acquisition unit 90 updates the deviation-related information for the operation pattern stored in the storage unit 50. Therefore, it is possible to update the deviation-related information for each operation pattern every time a shift operation is executed. Thus, for example, even when the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 changes due to aging or the like, it is possible to update the information and make the storage unit 50 store more accurate deviation-related information. Therefore, even when the second rotation sensor 52 malfunctions, it is possible to calculate the rotation angle of the output shaft 60 with higher accuracy.

[0076] In addition, according to the present embodiment, the deviation-related information includes an idling angle, which is the amount of change in the rotation angle of the motor unit 20 from the start of rotation of the motor unit 20 until the start of rotation of the output shaft 60. The information acquisition unit 90 can calculate the idling angle based on the detection results of the first rotation sensor 51 and the second rotation sensor 52. The main reason for the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 is, for example, an idling state in which the output shaft 60 does not rotate even when the motor unit 20 rotates. Therefore, by acquiring the idling angle by the information acquisition unit 90 and storing it in the storage unit 50, even when the second rotation sensor 52 fails, the idling angle stored in the storage unit 50 can be used to calculate the rotation angle of the output shaft 60 with higher accuracy.

[0077] In addition, according to the present embodiment, the deviation-related information for each operation pattern of all combinations of the previous shift operation and the current shift operation is stored in the storage unit 50. Therefore, when the second rotation sensor 52 fails, regardless of the shift operation of any operation pattern, the deviation-related information corresponding to each operation pattern can be used to appropriately correct the calculated rotation angle of the output shaft 60. Thus, when the second rotation sensor 52 fails, regardless of the shift operation performed, a decrease in the control accuracy of the rotation angle of the output shaft 60 can be appropriately suppressed.

[0078] The present invention is not limited to the above-described embodiment, and other structures and other methods can also be adopted within the scope of the technical idea of the present invention. The deviation-related information stored in the storage unit only needs to include the deviation-related information in the case of performing at least two or more operation patterns, and any information can be included.

[0079] It is also possible not to store the deviation-related information of the operation pattern in which the deviation between the rotation of the motor unit and the rotation of the output shaft is small in the storage unit. Specifically, in the above Figure 5 example, it is also possible not to store the idling angle of the operation pattern in which the previous shift operation is "R←N" or "R←D" and the current shift operation is "P←R", the idling angle of the operation pattern in which the previous shift operation is "P→N" or "R→N" and the current shift operation is "N→D", the idling angle of the operation pattern in which the previous shift operation is "P→R" and the current shift operation is "R→N" or "R→D", and the idling angle of the operation pattern in which the previous shift operation is "N←D" and the current shift operation is "P←N" or "R←N".

[0080] For example, it is also possible to divide the operation patterns into multiple groups, and store the deviation-related information for each group in the storage unit. Specifically, for example, it is also possible to Figure 5The operation patterns of the 36 patterns shown are divided into groups G1 to G10 shown surrounded by a dashed line. Each of group G1 and group G2 contains 9 operation patterns. The operation patterns included in group G1 are the operation patterns where the previous shift operation is a shift from a gear other than the parking gear P to the parking gear P, and the current shift operation is a shift from the parking gear P to a gear other than the parking gear P. The operation patterns included in group G2 are the operation patterns where the previous shift operation is a shift from a gear other than the drive gear D to the drive gear D, and the current shift operation is a shift from the drive gear D to a gear other than the drive gear D.

[0081] Each of group G3 and group G4 contains 1 operation pattern. The operation pattern included in group G3 is the operation pattern where the previous shift operation is a shift from the parking gear P to the reverse gear R, and the current shift operation is a shift from the reverse gear R to the parking gear P. The operation pattern included in group G4 is the operation pattern where the previous shift operation is a shift from the drive gear D to the neutral gear N, and the current shift operation is a shift from the neutral gear N to the drive gear D.

[0082] Each of group G5, group G6, group G7, and group G8 contains 2 operation patterns. The operation pattern included in group G5 is the operation pattern where the previous shift operation is a shift from the neutral gear N or the drive gear D to the reverse gear R, and the current shift operation is a shift from the reverse gear R to the parking gear P. The operation pattern included in group G6 is the operation pattern where the previous shift operation is a shift from the parking gear P or the reverse gear R to the neutral gear N, and the current shift operation is a shift from the neutral gear N to the drive gear D. The operation pattern included in group G7 is the operation pattern where the previous shift operation is a shift from the parking gear P to the reverse gear R, and the current shift operation is a shift from the reverse gear R to the neutral gear N or the drive gear D. The operation pattern included in group G8 is the operation pattern where the previous shift operation is a shift from the drive gear D to the neutral gear N, and the current shift operation is a shift from the neutral gear N to the parking gear P or the reverse gear R.

[0083] Each of group G9 and group G10 contains 4 operation patterns. The operation patterns included in group G9 are the operation patterns where the previous shift operation is a shift from the neutral gear N or the drive gear D to the reverse gear R, and the current shift operation is a shift from the reverse gear R to the neutral gear N or the drive gear D. The operation patterns included in group G10 are the operation patterns where the previous shift operation is a shift from the parking gear P or the reverse gear R to the neutral gear N, and the current shift operation is a shift from the neutral gear N to the parking gear P or the reverse gear R.

[0084] The groups G1 to G10 are divided from each other according to the operating patterns with the same degree of idling angle values of the motor unit 20. By grouping the operating patterns in this way, for example, in each of the groups G1 to G10, the idling angles of the operating patterns included in the same group are set to the same value and the storage unit 50 stores them. That is, the storage unit 50 stores the deviation-related information one by one according to each group G1 to G10. Thus, compared with the case where the storage unit 50 stores the deviation-related information according to each operating pattern, the number of information stored in the storage unit 50 can be reduced. In the above example, the 36 pieces of information related to the deviation of each operating pattern can be reduced to 10 pieces of information related to the deviation of each group G1 to G10. Therefore, the capacity of the storage unit 50 can be reduced. The deviation-related information stored corresponding to each group G1 to G10 can be, for example, the average value of the deviation-related information of the operating patterns included in each group.

[0085] In addition, in the case of grouping the operating patterns as described above, for example, when one operating pattern is performed, the information acquisition unit 90 can update the deviation-related information corresponding to the group including the operating pattern. Therefore, when one operating pattern is performed, the deviation-related information corresponding to the other operating patterns included in the same group is also updated. Thus, for the operating patterns that are rarely executed, the deviation-related information can also be appropriately updated.

[0086] In addition, even in the case of storing the deviation-related information in groups as described above, by setting the operating patterns with the same degree of idling angle to the same group, thus, in the case where the second rotation sensor 52 fails, the rotation angle of the output shaft 60 can be calculated with high accuracy using the deviation-related information corresponding to each group.

[0087] The deviation-related information stored in the storage unit may not be updated and may be maintained in the pre-stored state. In this case, the control device may not include the information acquisition unit. In the storage unit, the deviation-related information may be stored without overwriting, or may be overwritten sequentially starting from the old information after a specified number of pieces of deviation-related information are stored. The deviation-related information stored in the storage unit may not be pre-stored. In this case, it may be that each time a shift operation is performed to control the motor unit, the information acquisition unit stores the deviation-related information in the storage unit.

[0088] The transmission mechanism unit only needs to be able to transmit the rotation of the motor unit to the output shaft and can be of any structure. The transmission mechanism unit may also be a speed increaser or a mechanism that does not change the speed of the rotation of the motor unit.

[0089] The first rotation sensor only needs to be able to detect the rotation of the motor unit and can be any sensor. The second rotation sensor only needs to be able to detect the rotation of the output shaft and can be any sensor. The first rotation sensor and the second rotation sensor can also be magnetoresistive elements or optical sensors. A plurality of the first rotation sensors can also be provided. A plurality of the second rotation sensors can also be provided.

[0090] Each structure and each method described in the present specification above can be appropriately combined within a range that does not conflict with each other.

Claims

1. A control device is provided in an electric actuator which is mounted on a vehicle and has a motor unit, a transmission mechanism unit that transmits the rotation of the motor unit to an output shaft, a first rotation sensor capable of detecting the rotation of the motor unit, and a second rotation sensor capable of detecting the rotation of the output shaft. The control device controls the motor unit based on the rotation angle of the output shaft according to a shift operation of the vehicle. Among them, the control device has: a rotation angle calculation unit that can calculate the rotation angle of the output shaft based on the detection result of the second rotation sensor; and a storage unit that stores deviation-related information between the rotation of the motor unit and the rotation of the output shaft in cases where at least two or more operation patterns with different combinations of the last performed shift operation and the currently performed shift operation are provided. The deviation-related information includes the deviation amount between the rotation of the motor unit and the rotation of the output shaft, and data capable of calculating the deviation between the rotation of the motor unit and the rotation of the output shaft. When a failure occurs in the second rotation sensor, the rotation angle calculation unit calculates the rotation angle of the output shaft based on the detection result of the first rotation sensor and the deviation-related information.

2. The control device according to claim 1, wherein the control device further has an information acquisition unit that can acquire the deviation-related information based on the detection results of the first rotation sensor and the second rotation sensor, information related to the last performed shift operation is stored in the storage unit, the information acquisition unit discriminates the operation pattern based on the information related to the last performed shift operation stored in the storage unit, and causes the storage unit to store the acquired deviation-related information as the deviation-related information for the discriminated operation pattern.

3. The control device according to claim 2, wherein when the operation pattern for which the deviation-related information has been stored in the storage unit is performed, the information acquisition unit updates the deviation-related information for the operation pattern stored in the storage unit.

4. The control device according to claim 2, wherein the deviation-related information includes an idle rotation angle which is the amount of change in the rotation angle of the motor unit from the start of rotation of the motor unit to the start of rotation of the output shaft, the information acquisition unit can calculate the idle rotation angle based on the detection results of the first rotation sensor and the second rotation sensor.

5. The control device according to any one of claims 1 to 4, wherein deviation-related information for each of the operation patterns of all combinations of the last performed shift operation and the currently performed shift operation is stored in the storage unit.

6. The control device according to any one of claims 1 to 4, wherein the operation patterns are divided into multiple groups, and deviation-related information for each group is stored in the storage unit.

7. An electric actuator mounted on a vehicle, wherein, the electric actuator has: a motor section; a transmission mechanism section that transmits the rotation of the motor section to an output shaft; a first rotation sensor that can detect the rotation of the motor section; a second rotation sensor that can detect the rotation of the output shaft; and a control device according to any one of claims 1 to 4.

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