JP7480649B2 - Control device and electric actuator - Google Patents

Description

The present invention relates to a control device and an electric actuator.

An electric actuator is known that includes a motor unit and a transmission mechanism unit that transmits the rotation of the motor unit to an output shaft. For example, Patent Document 1 describes a rotary actuator that is used as a drive unit of a shift-by-wire system that switches the shift of an automatic transmission of a vehicle as one such electric actuator.

JP 2013-247798 A

In the electric actuator described above, the motor unit may be controlled based on the detection results of a rotation sensor capable of detecting the rotation angle of the output shaft, thereby controlling the rotation angle of the output shaft. However, in this case, if the rotation sensor capable of detecting the rotation angle of the output shaft breaks down, there is a risk that the control accuracy of the rotation angle of the output shaft will decrease.

In view of the above circumstances, one of the objects of the present invention is to provide a control device that can prevent a decrease in the control accuracy of the rotation angle of the output shaft even if a rotation sensor capable of detecting the rotation angle of the output shaft fails, and an electric actuator equipped with such a control device.

One aspect of the control device of the present invention is a control device that is provided in an electric actuator that is mounted on a vehicle and 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, and a second rotation sensor that can detect the rotation of the output shaft, and that controls the motor unit based on the rotation angle of the output shaft in response to a shift operation of the vehicle, and 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 information about the deviation between the rotation of the motor unit and the rotation of the output shaft when at least two or more operation patterns are performed in which the combination of the previous shift operation and the current shift operation is different from each other. 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 information about the deviation.

One aspect of the electric actuator of the present invention is an electric actuator mounted on a vehicle, and 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-mentioned control device.

According to one aspect of the present invention, even if a rotation sensor capable of detecting the rotation angle of an output shaft in an electric actuator fails, it is possible to prevent a decrease in the control accuracy of the rotation angle of the output shaft.

FIG. 1 is a diagram showing an actuator device in which an electric actuator according to the present embodiment is mounted, and shows a case where a lock gear is in an unlocked state. FIG. 2 is a diagram showing an actuator device in which the electric actuator of this embodiment is mounted, and shows a case where the lock gear is in a locked state. FIG. 3 is a top view of a portion of an actuator device in which the electric actuator of this embodiment is mounted. FIG. 4 is a block diagram showing the functional configuration of the electric actuator of this embodiment. FIG. 5 is a diagram showing an example of the idling angle of the motor unit stored in the storage unit of the present embodiment. FIG. 6 is a flowchart showing an example of a control procedure for the electric actuator of this embodiment.

In each figure, the Z-axis direction is the up-down direction with the positive side at the top and the negative side at the bottom. The axial direction of the central axis J, which is a virtual axis appropriately shown in each figure, is, for example, 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 the "axial direction Z." Furthermore, unless otherwise specified, the radial direction centered on the central axis J is simply referred to as the "radial direction." Furthermore, the direction of counterclockwise rotation around the central axis J as viewed from above is referred to as the "first rotation direction θ1," and the direction of clockwise rotation around the central axis J as viewed from above is referred to as the "second rotation direction θ2."

In addition, in each figure, the X-axis direction is perpendicular to the Z-axis direction, and the Y-axis direction is perpendicular to both the X-axis direction and the Z-axis direction. The direction parallel to the X-axis direction is called the "front-rear direction X," and the direction parallel to the Y-axis direction is called the "left-right direction Y." In the front-rear direction X, the positive side (+X side) of the X-axis direction is the front side, and the negative side (-X side) of the X-axis direction is the rear side. In the left-right direction Y, the positive side (+Y side) of the Y-axis direction is the left side, and the negative side (-Y side) of the Y-axis direction is the right side.

Note that the terms up-down, front-back, left-right, upper, lower, front, rear, left side, and right side are simply names used to describe the relative positional relationships of the various parts, and the actual positional relationships may be other than those indicated by these names.

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

The actuator device 1 also switches the lock gear G between a locked state and an unlocked state based on the driver's shift operation. The actuator device 1 locks the lock gear G when the vehicle's gear is in parking P, and unlocks the lock gear G when the vehicle's gear is other than parking P. The lock gear G is a gear connected to the axle. The lock gear G has multiple teeth Ga on its outer circumferential surface, and rotates around a rotation axis Gj extending in the left-right direction Y.

The actuator device 1 includes an electric actuator 10, an output shaft 60, an oil passage body 80, an arm operating unit 61, a valve operating unit 62, a lock arm 71, and a manual valve 72. The output shaft 60 is, for example, cylindrical and extends in the axial direction Z around a central axis J. The output shaft 60 is rotated around the central axis J by the electric actuator 10.

The oil passage body 80 has a hydraulic circuit therein that is made up of multiple oil passages. As shown in FIG. 3, the oil passage body 80 has an insertion hole 81 recessed in the left-right direction Y. Although not shown, the insertion hole 81 is connected to an oil passage inside the oil passage body 80. Inside the insertion hole 81, a manual valve 72 is arranged 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. When the manual valve 72 moves in the left-right direction Y, the connections between the oil passages inside the oil passage body 80 change, and the hydraulic circuit is switched.

As shown in Figs. 1 and 2, the arm operating unit 61 has a connecting portion 61a, a rod 61b, a support portion 61c, a flange portion 61e, and a coil spring 61f. The connecting portion 61a is fixed to the output shaft 60. The connecting portion 61a protrudes, for example, radially outward from the output shaft 60. The rod 61b is arranged to be movable along the front-rear direction X. For example, the rear end of the rod 61b is connected to the connecting portion 61a.

The support portion 61c is shaped like a truncated cone centered on an axis extending in the front-rear direction X. The outer diameter of the support portion 61c increases from the front to the rear. The support portion 61c has a through hole 61d that passes through the support portion 61c in the front-rear direction X. The front end of the rod 61b passes through the through hole 61d. The support portion 61c is movable in the front-rear direction X relative to the rod 61b. The support portion 61c and the rod 61b are, for example, arranged concentrically. The flange portion 61e is fixed to the rod 61b rearward of the support portion 61c.

The coil spring 61f extends in the front-rear direction X. The coil spring 61f is disposed between the support portion 61c and the flange portion 61e in the front-rear direction X. The rod 61b passes through the inside of the coil spring 61f. The rear end of the coil spring 61f contacts the flange portion 61e. The front end of the coil spring 61f contacts the support portion 61c. The coil spring 61f expands and contracts as the support portion 61c moves relative to the rod 61b in the front-rear direction X, applying an elastic force in the front-rear direction X to the support portion 61c.

The valve operating unit 62 is fixed to, for example, the lower end of the output shaft 60. As shown in FIG. 3, the valve operating unit 62 protrudes, for example, radially outward from the output shaft 60. The tip of the valve operating unit 62 is connected to the manual valve 72.

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

The electric actuator 10 can switch the position of the valve operating unit 62 between a parking position PP and a non-parking position based on the driver's shift operation. The non-parking positions are positions other than the parking position PP, and in this embodiment, as shown in FIG. 3, include a drive position DP, a neutral position NP, and a reverse position RP. That is, in this embodiment, the electric actuator 10 switches the position of the valve operating unit 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 this embodiment, the parking position PP is a locked position where the lock gear G is in a locked state, and the non-parking position is an unlocked position where the lock gear G is in an unlocked state.

The drive position DP is the position of the valve operating unit 62 when the vehicle's gear is drive D. The neutral position NP is the position of the valve operating unit 62 when the vehicle's gear is neutral N. The reverse position RP is the position of the valve operating unit 62 when the vehicle's gear is reverse R. The parking position PP is the position of the valve operating unit 62 when the vehicle's gear is parking P. FIG. 1 shows, for example, a case where the valve operating unit 62 is in the reverse position RP among the non-parking positions. FIG. 2 shows, for example, a case where the valve operating unit 62 is in the parking position PP.

As shown in FIG. 3, in the parking position PP, the valve operating unit 62 is disposed along a virtual line LP that is inclined toward the second rotational direction θ2 with respect to the fore-and-aft direction X when viewed from above. Although not shown, in the reverse position RP, the valve operating unit 62 is disposed along a virtual line LR that extends in the fore-and-aft direction X when viewed from above. In the neutral position NP, the valve operating unit 62 is disposed along a virtual line LN that is inclined toward the first rotational direction θ1 with respect to the fore-and-aft direction X when viewed from above. In the drive position DP, the valve operating unit 62 is disposed along a virtual line LD that is inclined toward the first rotational direction θ1 more than the virtual line LN with respect to the fore-and-aft direction X when viewed from above.

The position in the left-right direction Y of the tip of the valve operating unit 62 is, for example, from left to right in the order of parking position PP, reverse position RP, neutral position NP, and drive position DP. As the position in the left-right direction Y of the tip of the valve operating unit 62 changes, the position in the left-right direction Y of the manual valve 72 to which the tip of the valve operating unit 62 is connected also changes. In other words, the position in the left-right direction Y of the manual valve 72 is from left to right in the order of parking position PP, reverse position RP, neutral position NP, and drive position DP. In this way, the valve operating unit 62 moves the manual valve 72.

As shown in Figs. 1 and 2, the lock arm 71 is disposed, for example, in front of the arm operating unit 61. The lock arm 71 is disposed rotatably about a rotation shaft 71d. The rotation shaft 71d is an axis extending in the left-right direction Y. The lock arm 71 has a first portion 71a and a second portion 71b. The first portion 71a extends rearward from the rotation shaft 71d. The rear end of the first portion 71a contacts the outer peripheral surface of the support portion 61c. The second portion 71b extends upward from the rotation shaft 71d at a slight forward incline. The second portion 71b has an engagement portion 71c at its upper end that protrudes forward.

The lock arm 71 rotates around the rotation axis 71d as the rod 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 state shown in FIG. 1, the rod 61b and the support portion 61c move forward. Since the outer diameter of the support portion 61c increases from the front to the rear, when the support portion 61c moves forward, the first portion 71a that contacts the support portion 61c is lifted upward, and the lock arm 71 rotates counterclockwise around the rotation axis 71d as viewed from the left side. As a result, the meshing portion 71c approaches the lock gear G and meshes between the teeth portions Ga as shown in FIG. 2.

At this time, depending on the position of the tooth portion Ga, the meshing portion 71c may come into contact with the tooth portion Ga, and the lock arm 71 may not be able to rotate to a position where the meshing portion 71c meshes between the tooth portions Ga. Even in such a case, in this embodiment, since the support portion 61c is movable in the forward/rearward direction X relative to the rod 61b, it is possible to allow the rod 61b to move to the parking position PP while the support portion 61c is positioned behind the parking position PP. This makes it possible to prevent the rotation of the output shaft 60 from being hindered, and to prevent a load from being applied to the electric actuator 10.

When the rod 61b is in the parking position PP and the support portion 61c is located behind the parking position PP, the coil spring 61f is compressed and deformed. Therefore, a forward elastic force is applied to the support portion 61c by the coil spring 61f. As a result, a rotational moment is applied from the coil spring 61f to the lock arm 71 via the support portion 61c in a counterclockwise direction around the rotation shaft 71d as viewed from the left side. Therefore, when the lock gear G rotates and the position of the teeth portion Ga shifts, the lock arm 71 rotates and the meshing portion 71c meshes between the teeth portions Ga.

On the other hand, for example, when the output shaft 60 rotates in the first rotation direction θ1 from the state shown in FIG. 2, the rod 61b and the support portion 61c move rearward. When the support portion 61c moves rearward, the first portion 71a that was held up by the support portion 61c moves downward by its own weight or by receiving force from the lock gear G, and the lock arm 71 rotates clockwise as viewed from the left side around the rotation axis 71d. As a result, the meshing portion 71c separates from the lock gear G and comes out from between the teeth portions Ga as shown in FIG. 1.

As shown in FIG. 4, 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 an output shaft 60. For example, the transmission mechanism unit 30 is connected to a shaft of a rotor (not shown) in the motor unit 20. In this embodiment, the transmission mechanism unit 30 is a reducer.

In this specification, the rotation of the motor unit 20 refers to the rotation of a rotor (not shown) in the motor unit 20. In addition, in this specification, the rotation angle of the motor unit 20 refers to the rotation angle of a rotor (not shown) in the motor unit 20, and the rotational angular velocity of the motor unit 20 refers to the rotational angular velocity of a rotor (not shown) in the motor unit 20.

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 is capable of detecting, for example, the rotation of a shaft (not shown) in the motor unit 20. The first rotation sensor 51 detects the rotation of the motor unit 20 at predetermined intervals. 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.

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 predetermined 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.

The control device 40 is provided in the electric actuator 10 mounted on the vehicle, and controls the motor unit 20 based on the rotation angle of the output shaft 60 in response to the shift operation of the vehicle. In this 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 fault detection unit 49, a memory unit 50, and an information acquisition unit 90. Note that each part of the control device 40 shown by the functional blocks in FIG. 4 may be configured in any way in the control device 40 as long as the control device 40 has the functions of each part.

The rotation angle command unit 41 receives a movement command CS. The movement command CS is a signal sent to the electric actuator 10 when the vehicle is shifted. The movement command CS is sent, for example, from the engine control unit of the vehicle. The movement command CS includes information about which gear the vehicle is to be shifted to. The rotation angle command unit 41 outputs a target angle command 41a to the rotation angle control unit 42 based on the movement command CS. The target angle command 41a includes a target rotation angle of the output shaft 60.

The rotation angle control unit 42 outputs an angular velocity command 42a to the rotation angular velocity control unit 43 based on the input target angle command 41a. The rotation angular velocity control unit 43 outputs a current command 43a to the current control unit 44 based on the input angular velocity command 42a. The current control unit 44 sends a signal to the inverter unit 45 based on the current command 43a. A current is supplied to the inverter unit 45 from outside the electric actuator 10. The inverter unit 45 converts the frequency of the current supplied from outside based on 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.

The rotational angular velocity calculation unit 47 receives a signal from the first rotation sensor 51. The rotational angular velocity calculation unit 47 can calculate the rotational angular velocity of the motor unit 20 based on 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 based on 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 manner, the rotation of the motor unit 20 can be suitably controlled. The rotational angular velocity of the motor unit 20 calculated by the rotational angular velocity calculation unit 47 is input to the rotational angular velocity control unit 43.

The rotation angle calculation unit 48 receives a signal from the second rotation sensor 52. The rotation angle calculation unit 48 can calculate the rotation angle of the output shaft 60 based on 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 input to the rotation angle control unit 42. In this embodiment, the rotation angle calculation unit 48 also receives a signal from the first rotation sensor 51. In this embodiment, the rotation angle calculation unit 48 can calculate the rotation angle of the motor unit 20 based on the detection result of the first rotation sensor 51.

The fault detection unit 49 receives a signal from the second rotation sensor 52. The fault detection unit 49 can detect whether the second rotation sensor 52 has failed based on the detection result of the second rotation sensor 52. The fault detection unit 49 determines that the second rotation sensor 52 has failed, for example, when an error signal is received from the second rotation sensor 52, or when the value of the signal received from the second rotation sensor 52 is invalid. A case where the value of the signal received from the second rotation sensor 52 is invalid includes, for example, a case where the value of the signal received from the second rotation sensor 52 is different from the value of the signal previously received from the second rotation sensor 52 by a predetermined value or more. The detection result of the fault detection unit 49 is received by the rotation angle calculation unit 48.

The memory unit 50 stores information regarding the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 when at least two or more operation patterns are performed, each of which has a different combination of the previous vehicle shift operation and the current vehicle shift operation. A vehicle shift operation is an operation performed by a driver or the like to change the vehicle gear from one state to another state. In this embodiment, the vehicle shift operation is an operation performed to change the vehicle gear from one of the states of parking P, reverse R, neutral N, and drive D to another state. In this specification, an "operation pattern" is a pattern consisting of a combination of the previous vehicle shift operation and the current vehicle shift operation.

The information regarding the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 includes the amount of deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60, data that allows the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 to be calculated, etc. The data that allows the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 to be calculated includes the detection result of the first rotation sensor 51, the detection result of the second rotation sensor 52, an assembly error of the electric actuator 10, an error in the reduction ratio of the transmission mechanism unit 30, etc.

The misalignment between the rotation of the motor unit 20 and the rotation of the output shaft 60 occurs, for example, due to play in the connection between the motor unit 20 and the transmission mechanism unit 30. In this embodiment, the information regarding the misalignment 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 amount of change in the rotation angle of the motor unit 20 from when the motor unit 20 starts to rotate until when the output shaft 60 starts to rotate. In other words, the idling angle is the angle at which the motor unit 20 rotates idly from when the motor unit 20 starts to rotate until when the output shaft 60 starts to rotate. In the following description, the information regarding the misalignment between the rotation of the motor unit 20 and the rotation of the output shaft 60 is simply referred to as "information regarding the misalignment."

In this embodiment, the storage unit 50 stores information about the deviation for each operation pattern of all combinations of the previous shift operation and the current shift operation. Specifically, for example, the storage unit 50 stores information about the deviation for each of the 36 operation patterns shown in FIG. 5. In this embodiment, the storage unit 50 stores information about the deviation for each operation pattern in advance.

5 shows the idling angle [°] of the motor unit 20 as information on the deviation. In FIG. 5, "P" indicates parking P, "R" indicates reverse R, "N" indicates neutral N, and "D" indicates drive D. In the previous shift operation and the current shift operation, the arrows between the symbols "P", "R", "N", and "D" indicate the direction in which the gear of the vehicle is changed in the shift operation. For example, "P→R" indicates a shift operation in which the gear of the vehicle is changed from parking P to reverse R. For example, "P←R" indicates a shift operation in which the gear of the vehicle is changed from reverse R to parking P. The direction of the arrows in FIG. 5 corresponds to the direction in which the manual valve 72 shown in FIG. 3 moves. For example, in the shift operation of "P→R", the manual valve 72 moves to the right (-Y side). For example, in the shift operation of "P←R", the manual valve 72 moves to the left (+Y side).

In FIG. 5, for example, the value entered in the column where the previous shift operation was "P→R" and the current shift operation is "P←R" indicates the idling angle [°] of the motor unit 20 when a shift operation is performed to change the vehicle's gear from parking P to reverse R, and then a shift operation is performed to change the vehicle's gear from reverse R to parking P.

In FIG. 5, when the idling angle is a positive value, the direction in which the motor unit 20 rotates idly is the direction in which the motor unit 20 rotates when the output shaft 60 rotates in the first rotation direction θ1. When the idling angle is a negative value, the direction in which the motor unit 20 rotates idly is the direction in which the motor unit 20 rotates when the output shaft 60 rotates in the second rotation direction θ2.

As shown in FIG. 5, the idling angle of the motor unit 20 when performing the current shift operation may differ depending on the type of shift operation performed last time. In other words, even if the current shift operation is the same, if the previous shift operation is different, the idling angle when performing the current shift operation may differ. In the example of FIG. 5, if the direction in which the motor unit 20 rotates when the current shift operation is performed is the same as the direction in which the motor unit 20 rotated when the previous shift operation was performed, the idling angle of the motor unit 20 is relatively small. In other words, in the example of FIG. 5, if the direction in which the manual valve 72 moves when the current shift operation is performed is the same as the direction in which the manual valve 72 moved when the previous shift operation was performed, the idling angle of the motor unit 20 is relatively small.

On the other hand, in the example of FIG. 5, if the direction in which the motor unit 20 rotates when the current shift operation is performed is opposite to the direction in which the motor unit 20 rotated when the previous shift operation was performed, the idling angle of the motor unit 20 becomes relatively large. In other words, in the example of FIG. 5, if the direction in which the manual valve 72 moves when the current shift operation is performed is opposite to the direction in which the manual valve 72 moved when the previous shift operation was performed, the idling angle of the motor unit 20 becomes relatively large.

The magnitude relationship of the idling angle of the motor unit 20 is not limited to the example of FIG. 5 described above. For example, if the direction in which the motor unit 20 rotates when the current shift operation is performed is the same as the direction in which the motor unit 20 rotated when the previous shift operation was performed, the idling angle of the motor unit 20 may be relatively large. Also, for example, if the direction in which the motor unit 20 rotates when the current shift operation is performed is opposite to the direction in which the motor unit 20 rotated when the previous shift operation was performed, the idling angle of the motor unit 20 may be relatively small. The magnitude relationship of the idling angle of the motor unit 20 may change due to, for example, the magnitude of the braking force applied to the output shaft 60 by the motor unit 20 when the rotation of the motor unit 20 stops.

The memory unit 50 stores information about the previous shift operation. For example, the memory unit 50 stores information about which state the vehicle's gear was changed to from among parking P, reverse R, neutral N, and drive D in the previous shift operation. The information about the previous shift operation stored in the memory unit 50 is overwritten, for example, each time a new shift operation is performed.

As shown in FIG. 4, the information acquisition unit 90 receives a signal from the first rotation sensor 51 and a signal from the second rotation sensor 52. The information acquisition unit 90 can acquire information related to the deviation based on the detection results of the first rotation sensor 51 and the second rotation sensor 52. In this 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, the information acquisition unit 90 calculates, for example, the rotation angle of the motor unit 20 from the time when the motor unit 20 starts to rotate to the time when the output shaft 60 starts to rotate based on the signal input from the first rotation sensor 51 and the signal input from the second rotation sensor 52 as the idling angle.

In this embodiment, the information acquisition unit 90 determines an operation pattern based on information about the previously performed shift operation stored in the storage unit 50, and stores the obtained information about the deviation in the storage unit 50 as information about the deviation for the determined operation pattern. At this time, if information about the deviation for the executed operation pattern is already stored in the storage unit 50, the information about the deviation for that operation pattern is overwritten. In other words, in this embodiment, when an operation pattern is performed for which information about the deviation is already stored in the storage unit 50, the information acquisition unit 90 updates the information about the deviation for the operation pattern stored in the storage unit 50.

The control device 40 controls the motor unit 20 according to the flowchart shown in FIG. 6, for example. After starting control of the motor unit 20 based on the current shift operation (step S1), the control device 40 judges whether the second rotation sensor 52 is operating normally (step S2). In this embodiment, the control device 40 judges whether the second rotation sensor 52 is malfunctioning or not by the fault detection unit 49, and judges whether the second rotation sensor 52 is operating normally or not. If the fault detection unit 49 judges that the second rotation sensor 52 is not malfunctioning, the control device 40 judges that the second rotation sensor 52 is operating normally. On the other hand, if the fault detection unit 49 judges that the second rotation sensor 52 is malfunctioning, the control device 40 judges that the second rotation sensor 52 is not operating normally.

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 by 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).

After starting to rotate the motor unit 20, the control device 40 determines whether the output shaft 60 has started to rotate (step S5). In this 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. A change in the signal from the second rotation sensor 52 is, for example, when the voltage value of the signal input from the second rotation sensor 52 to the information acquisition unit 90 exceeds a predetermined threshold value.

When it is determined that the output shaft 60 has started to rotate (step S5: YES), the control device 40 stores the idling angle of the motor unit 20 in the memory unit 50 (step S6). Specifically, in this embodiment, the control device 40 causes the information acquisition unit 90 to store the rotation angle of the motor unit 20 from the time when the motor unit 20 starts to rotate to the time when the output shaft 60 starts to rotate as the idling angle in the memory unit 50. At this time, since the idling angle of the motor unit 20 for each operation pattern is stored in advance in the memory unit 50 in this embodiment, the information acquisition unit 90 overwrites the idling angle according to the determined operation pattern. Note that step S6 is executed, for example, once each time a shift operation is performed.

The control device 40 continues to rotate the motor unit 20 even after the output shaft 60 starts to rotate, and determines whether the rotation angle of the output shaft 60 has reached the target rotation angle (step S7). If 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 continues to control the motor unit 20 while, for example, determining whether the second rotation sensor 52 is operating normally (step S2). If 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 controlling the motor unit 20 (step S8).

On the other hand, if 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 memory unit 50 (step S3b). In this embodiment, the control device 40 calculates the rotation angle of the output shaft 60 in the rotation angle calculation unit 48 based on the detection result of the first rotation sensor 51 and the idling angle of the motor unit 20. In other words, in this 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 regarding the deviation.

Specifically, the rotation angle calculation unit 48 calculates the rotation angle of the output shaft 60 by, for example, 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, and dividing the result by the reduction ratio of the transmission mechanism unit 30, which is a reducer. The control device 40 rotates the motor unit 20 based on the calculated rotation angle of the output shaft 60 (step S4b). Thereafter, the control device 40 performs steps S7 and S8 in the same manner as when the second rotation sensor 52 is normal.

As described above, for example, there may be play in the connection between the motor unit 20 and the transmission mechanism unit 30, which may cause a misalignment between the rotation of the motor unit 20 and the rotation of the output shaft 60. Therefore, for example, if the rotation angle of the output shaft 60 is calculated only from the rotation angle of the motor unit 20 detected based on 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.

In contrast, according to this 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 regarding 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 by the information regarding the deviation. This allows the rotation angle of the output shaft 60 to be calculated with higher accuracy than when the rotation angle of the output shaft 60 is calculated only from the detection result of the first rotation sensor 51.

Here, the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 may differ depending on the operation pattern being performed. Therefore, simply storing information about the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 in the memory unit 50 may not allow the rotation angle of the output shaft 60 to be calculated accurately when the operation pattern is different.

In contrast, according to this embodiment, the deviation information stored in the memory unit 50 includes deviation information for at least two or more operation patterns in which the previous shift operation and the current shift operation are combined in different ways. In other words, the memory unit 50 stores deviation information corresponding to two or more operation patterns. Therefore, the calculated rotation angle of the output shaft 60 can be appropriately corrected according to the operation pattern being executed. This allows the rotation angle of the output shaft 60 to be calculated with greater accuracy.

As described above, according to this embodiment, even if the second rotation sensor 52 capable of detecting the rotation angle of the output shaft 60 fails, it is possible to suppress a decrease in the control accuracy of the rotation angle of the output shaft 60. Therefore, even if the second rotation sensor 52 fails, the control device 40 can suitably control the motor unit 20 based on the shift operation of the vehicle. As a result, even if the second rotation sensor 52 fails, the electric actuator 10 can suitably switch the vehicle gear between Parking P, Reverse R, Neutral N, and Drive D.

Specifically, in this 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 rotation angle of the motor unit 20, the idling angle of the motor unit 20 stored in the memory unit 50, and the reduction ratio of the transmission mechanism unit 30, which is a reducer. Therefore, for example, the rotation angle of the output shaft 60 can be suitably calculated by dividing the angle obtained by subtracting the idling angle from the rotation angle of the motor unit 20 by the reduction ratio.

According to this embodiment, the electric actuator 10 further includes an information acquisition unit 90 capable of acquiring information related to the deviation based on the detection result of the first rotation sensor 51 and the detection result of the second rotation sensor 52. The information acquisition unit 90 determines an operation pattern based on information related to the previous shift operation stored in the storage unit 50, and stores the acquired information related to the deviation in the storage unit 50 as information related to the deviation for the determined operation pattern. Therefore, for example, even if the information related to the deviation is not stored in the storage unit 50 in advance, the information acquisition unit 90 can be used to make the storage unit 50 learn the information related to the deviation. Also, for example, before the electric actuator 10 is used, the motor unit 20 corresponding to all operation patterns can be controlled, and the information related to the deviation corresponding to all operation patterns can be stored in the storage unit 50.

Furthermore, according to this embodiment, when an operation pattern for which information on the deviation is already stored in the storage unit 50 is performed, the information acquisition unit 90 updates the information on the deviation for the operation pattern stored in the storage unit 50. Therefore, the information on the deviation for each operation pattern can be updated each time a shift operation is performed. As a result, even if the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 changes due to, for example, aging, the information can be updated and more accurate information on the deviation can be stored in the storage unit 50. Therefore, even if the second rotation sensor 52 fails, the rotation angle of the output shaft 60 can be calculated with higher accuracy.

According to this embodiment, the information on the deviation includes the idling angle, which is the amount of change in the rotation angle of the motor unit 20 from when the motor unit 20 starts to rotate until the output shaft 60 starts to rotate. 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 cause of the deviation between the rotation of the motor unit 20 and the rotation of the output shaft 60 is, for example, the occurrence of an idling state in which the motor unit 20 rotates but the output shaft 60 does not rotate. Therefore, by acquiring the idling angle by the information acquisition unit 90 and storing it in the storage unit 50, even if the second rotation sensor 52 fails, the rotation angle of the output shaft 60 can be calculated more accurately using the idling angle stored in the storage unit 50.

In addition, according to this embodiment, the memory unit 50 stores information regarding the deviation for each operation pattern of all combinations between the previous shift operation and the current shift operation. Therefore, if the second rotation sensor 52 fails, the calculated rotation angle of the output shaft 60 can be appropriately corrected using information regarding the deviation corresponding to each operation pattern, regardless of the operation pattern of the shift operation performed. As a result, if the second rotation sensor 52 fails, the control accuracy of the rotation angle of the output shaft 60 can be appropriately prevented from decreasing, regardless of the shift operation performed.

The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical idea of the present invention. The information on the deviation stored in the storage unit may include any information as long as it includes information on the deviation when at least two or more operation patterns are performed.

The storage unit does not need to store information about the deviation of the operation pattern in which the deviation between the rotation of the motor unit and the rotation of the output shaft is relatively small. Specifically, in the example of FIG. 5 described above, the idling angle in the operation pattern in which the previous shift operation was "R←N" or "R←D" and the current shift operation is "P←R", the idling angle in the operation pattern in which the previous shift operation was "P→N" or "R→N" and the current shift operation is "N→D", the idling angle in the operation pattern in which the previous shift operation was "P→R" and the current shift operation is "R→N" or "R→D", and the idling angle in the operation pattern in which the previous shift operation was "N←D" and the current shift operation is "P←N" or "R←N" do not need to be stored in the storage unit.

For example, the operation patterns may be divided into a plurality of groups, and the memory unit may store information regarding the deviation for each group. Specifically, for example, the 36 operation patterns shown in FIG. 5 may be divided into groups G1 to G10, which are surrounded by dashed lines. Groups G1 and G2 each include nine operation patterns. The operation patterns included in group G1 are operation patterns in which the previous shift operation is an operation of switching from a position other than parking P to parking P, and the current shift operation is an operation of switching from parking P to a position other than parking P. The operation patterns included in group G2 are operation patterns in which the previous shift operation is an operation of switching from a position other than drive D to drive D, and the current shift operation is an operation of switching from drive D to a position other than drive D.

Group G3 and group G4 each include one operation pattern. The operation pattern included in group G3 is an operation pattern in which the previous shift operation was an operation to switch from Parking P to Reverse R, and the current shift operation is an operation to switch from Reverse R to Parking P. The operation pattern included in group G4 is an operation pattern in which the previous shift operation was an operation to switch from Drive D to Neutral N, and the current shift operation is an operation to switch from Neutral N to Drive D.

Group G5, group G6, group G7, and group G8 each include two operation patterns. The operation patterns included in group G5 are operation patterns in which the previous shift operation is an operation of switching from neutral N or drive D to reverse R, and the current shift operation is an operation of switching from reverse R to parking P. The operation patterns included in group G6 are operation patterns in which the previous shift operation is an operation of switching from parking P or reverse R to neutral N, and the current shift operation is an operation of switching from neutral N to drive D. The operation patterns included in group G7 are operation patterns in which the previous shift operation is an operation of switching from parking P to reverse R, and the current shift operation is an operation of switching from reverse R to neutral N or drive D. The operation patterns included in group G8 are operation patterns in which the previous shift operation is an operation of switching from drive D to neutral N, and the current shift operation is an operation of switching from neutral N to parking P or reverse R.

Group G9 and group G10 each contain four operation patterns. The operation patterns contained in group G9 are operation patterns in which the previous shift operation was an operation of switching from neutral N or drive D to reverse R, and the current shift operation is an operation of switching from reverse R to neutral N or drive D. The operation patterns contained in group G10 are operation patterns in which the previous shift operation was an operation of switching from parking P or reverse R to neutral N, and the current shift operation is an operation of switching from neutral N to parking P or reverse R.

Each group G1 to G10 is divided into operation patterns that have approximately the same value of the idling angle of the motor unit 20. In this way, the operation patterns are divided into groups, and for example, the idling angles of the operation patterns included in the same group in each group G1 to G10 are stored in the storage unit 50 as the same value. That is, one piece of information regarding deviation is stored in the storage unit 50 for each group G1 to G10. This makes it possible to reduce the amount of information stored in the storage unit 50 compared to the case where information regarding deviation for each operation pattern is stored in the storage unit 50. In the above example, 36 pieces of information regarding deviation for each operation pattern can be reduced to 10 pieces of information regarding deviation for each group G1 to G10. Therefore, the capacity of the storage unit 50 can be reduced. The information regarding deviation stored corresponding to each group G1 to G10 can be, for example, the average value of the information regarding deviation for the operation patterns included in each group.

In addition, when the operation patterns are grouped as described above, for example, when one operation pattern is performed, the information on the deviation corresponding to the group including that operation pattern can be updated by the information acquisition unit 90. Therefore, when one operation pattern is performed, the information on the deviation corresponding to other operation patterns included in the same group is also updated. This makes it possible to preferably update the information on the deviation even for operation patterns that are rarely executed.

Even if information regarding the deviation is stored for each group as described above, by grouping operation patterns that result in similar idling angles together, if the second rotation sensor 52 fails, the rotation angle of the output shaft 60 can be calculated with high accuracy using information regarding the deviation corresponding to each group.

The information relating to the deviation stored in the memory unit may remain stored in advance and may not be updated. In this case, the control device may not have an information acquisition unit. The information relating to the deviation may be accumulated in the memory unit without being overwritten, or after a predetermined number of pieces of information relating to the deviation have been accumulated, the oldest pieces of information may be overwritten. The information relating to the deviation stored in the memory unit may not be stored in advance. In this case, the information relating to the deviation may be stored in the memory unit by the information acquisition unit each time a shift operation is performed and the motor unit is controlled.

The transmission mechanism may have any structure as long as it can transmit the rotation of the motor to the output shaft. The transmission mechanism may be a speed increaser or a mechanism that does not change the speed of the rotation of the motor.

The first rotation sensor may be any type of sensor that is capable of detecting the rotation of the motor unit. The second rotation sensor may be any type of sensor that is capable of detecting the rotation of the output shaft. The first rotation sensor and the second rotation sensor may be magnetic resistance elements or optical sensors. A plurality of first rotation sensors may be provided. A plurality of second rotation sensors may be provided.

The configurations and methods described above in this specification can be combined as appropriate within the limits of not being mutually inconsistent.

10...electric actuator, 20...motor section, 30...transmission mechanism section, 40...control device, 48...rotation angle calculation section, 50...storage section, 51...first rotation sensor, 52...second rotation sensor, 60...output shaft, 90...information acquisition section, G1, G2, G3, G4, G5, G6, G7, G8, G9, G10...groups

Claims (7)

A control device is provided in an electric actuator that is mounted on a vehicle and includes a motor unit, a transmission mechanism unit that transmits rotation of the motor unit to an output shaft, a first rotation sensor that can detect rotation of the motor unit, and a second rotation sensor that can detect rotation of the output shaft, and the control device controls the motor unit based on a rotation angle of the output shaft in response to a shift operation of the vehicle,
a rotation angle calculation unit capable of calculating a rotation angle of the output shaft based on a detection result of the second rotation sensor;
a storage unit that stores information regarding a deviation between a rotation of the motor unit and a rotation of the output shaft when at least two or more operation patterns are performed, each of which has a different combination of the previously performed shift operation and the currently performed shift operation;
Equipped with
The control device, when the second rotation sensor fails, wherein the rotation angle calculation unit calculates the rotation angle of the output shaft based on the detection result of the first rotation sensor and information related to the deviation. an information acquisition unit capable of acquiring information regarding the deviation based on a detection result of the first rotation sensor and a detection result of the second rotation sensor;
The storage unit stores information regarding the previously performed shift operation,
2. The control device according to claim 1, wherein the information acquisition unit determines the operation pattern based on information regarding the previously performed shift operation stored in the memory unit, and stores the acquired information regarding the deviation in the memory unit as information regarding the deviation for the determined operation pattern. The control device according to claim 2, wherein the information acquisition unit updates the information about the deviation for the operation pattern stored in the storage unit when the operation pattern for which the information about the deviation is already stored in the storage unit is performed. the information about the deviation includes an idling angle that is an amount of change in a rotation angle of the motor unit from when the motor unit starts to rotate to when the output shaft starts to rotate,
The control device according to claim 2 or 3, wherein the information acquisition unit is capable of calculating the idling angle based on a detection result of the first rotation sensor and a detection result of the second rotation sensor. The control device according to any one of claims 1 to 4, wherein the storage unit stores information regarding the deviation for each operation pattern for all combinations of the previous shift operation and the current shift operation. The operation patterns are divided into a plurality of groups,
The control device according to claim 1 , wherein the storage unit stores information regarding the deviation for each of the groups. An electric actuator mounted on a vehicle,
A motor unit;
a transmission mechanism for transmitting rotation of the motor unit to an output shaft;
A first rotation sensor capable of detecting rotation of the motor unit;
A second rotation sensor capable of detecting rotation of the output shaft;
A control device according to any one of claims 1 to 6;
An electric actuator comprising:

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