Actuator control device and actuator control method

Abstract

An actuator control device for controlling an actuator according to an angle of a rotating part (3 to 6) includes: a processor configured to: calculate a target relative angle from a rotation start angle to a target angle (S10); detect a sensor detection angle from a sensor (7) (S20 and S30); calculate an angular velocity of the rotating part based on a change in the sensor detection angle in a predetermined calculation cycle (S40); correct the angular velocity to be close to a normal angular velocity when the angular velocity is greater than or equal to a first threshold value or less than or equal to a second threshold value (S50 and S60 to S64); calculate an actual relative angle by integrating the angular velocity and the corrected angular velocity (S90); and feedback-control the actuator according to a deviation between the target relative angle and the actual relative angle (S100, S110).

Description

Technical Field

[0001] The present disclosure relates to an actuator control device for controlling driving of an actuator and an actuator control method. Background Art

[0002] Conventionally, an actuator control device is known that performs feedback control on an actuator so that the rotation angle of a rotating part (i.e., a gear or a controlled object) driven by the actuator matches a target rotation angle. In the following description, the rotation angle is simply referred to as "angle." Furthermore, angles are simply referred to as "degrees."

[0003] The sensor described in Patent Document 1 detects the angle of a rotating part and includes a magnet that rotates with the rotating part and a Hall effect IC placed outside the magnet. This sensor is configured so that the output waveform of the Hall effect element, which is based on the angle of the rotating part, approaches a linear shape (i.e., an ideal waveform) by designing the magnet to be elliptical when viewed from the rotation axis.

[0004] However, even with the sensor described in Patent Document 1, when the rotating part rotates more than 360 degrees, the sensor's output value may have a range where it lacks continuity at positions where the direction of magnetic flux passing through the magnetically sensitive surface of the Hall IC is reversed. This range of discontinuity in the sensor's output value is, in other words, the range where the amount of change in the sensor's output value in response to the angular change of the rotating part is reversed, and the range where the linearity of the ideal waveform is interrupted. In this specification, the center of the angular range where the sensor's output value lacks continuity is referred to as the "reference position." In the configuration of Patent Document 1, the sensor's output value lacks continuity when the rotating part's angle spans between 180 degrees and -180 degrees.

[0005] Typically, without being limited to the sensor described in Patent Document 1, a sensor that detects the angle of a rotating part has a reference position where the output value does not have continuity. In addition, typically, in the feedback control of the actuator, the angle for rotating the rotating part from the rotation start angle to the target angle (hereinafter referred to as the "target relative angle") is calculated by the equation "target relative angle" = "target angle" - "current angle of the rotating part". Therefore, in the feedback control for rotating the rotating part more than 360 degrees, when the output value of the sensor passes through the reference position, the target relative angle may not be correctly calculated, and the actuator may operate in the direction opposite to the desired operation. For example, in the case of using a sensor whose reference position is 0 degrees (i.e., 360 degrees), when the rotating part is 390 degrees, the angle is detected as 30 degrees based on the output value of the sensor. Therefore, for example, when calculating the target relative angle for rotating the rotating part from 350 degrees to 390 degrees, the correct calculation should be performed using the equation "target relative angle = 390 - 350 = 40", but the calculation may be incorrectly performed using the equation "target relative angle = 30 - 350 = -320". In this case, even if the original request is to rotate the actuator 40 degrees clockwise, the actuator will rotate 320 degrees counterclockwise, contrary to the original request.

[0006] [Patent Document 1] JP 2008-139108-A. Summary of the Invention

[0007] In view of the above points, an object of the present disclosure is to provide an actuator control device and an actuator control method that can accurately drive an actuator.

[0008] In order to achieve the above-mentioned purpose, the actuator control device controls the driving of the actuator according to the angle of the rotating part (3 to 6) rotated by the actuator (2) by more than 360 degrees. The actuator control device calculates the target relative angle for rotating the rotating part from the rotation starting angle to the target angle (at S10). Then, the output value of the sensor (7) that outputs the output signal corresponding to the angle of the rotating part is signal-processed to detect the sensor detection angle as the absolute angle of the rotating part (at S20 and S30). The angular velocity of the rotating part is calculated in a predetermined calculation cycle based on the change in the sensor detection angle (at S40). Then, when the angular velocity is greater than or equal to a first threshold value (set to a predetermined value less than 360 degrees / second and greater than 0 degrees / second), or when the angular velocity is less than or equal to a second threshold value (set to a predetermined value less than 0 degrees / second and greater than -360 degrees / second), correction is performed to make the angular velocity close to the normal angular velocity (at S50 and S60 to S64). Then, by integrating the angular velocity calculated in a predetermined calculation cycle and the corrected angular velocity, the actual relative angle to which the rotating part rotates from the rotation starting angle is calculated (at S90), and the drive of the actuator is feedback controlled based on the deviation between the target relative angle and the actual relative angle (at S100, S110).

[0009] As a result, when the sensor output value crosses the center of the angular range with discontinuity (hereinafter referred to as the "reference position"), correction is performed to bring the angular velocity closer to the normal angular velocity. Then, by integrating the corrected angular velocity with the angular velocity calculated in a predetermined calculation cycle, the actual relative angle can be continuously and accurately calculated even when the sensor output value crosses the reference position. Therefore, this actuator control device enables accurate feedback control of the actuator.

[0010] An actuator control method is provided for controlling the drive of an actuator according to the angle of a rotating part (3 to 6) rotated by an actuator (2) by more than 360 degrees. The actuator control method includes the following process. That is, a target relative angle for rotating the rotating part from a rotation start angle to a target angle is calculated (at S10). Then, a signal processing is performed on an output value of a sensor (7) that outputs an output signal corresponding to the angle of the rotating part to detect a sensor detection angle as an absolute angle of the rotating part (at S20 and S30). The angular velocity of the rotating part is calculated from the change in the sensor detection angle in a predetermined calculation cycle (at S40). Then, when the angular velocity is greater than or equal to a first threshold value (which is set to a predetermined value less than 360 degrees / second and greater than 0 degrees / second), or when the angular velocity is less than or equal to a second threshold value (which is set to a predetermined value less than 0 and greater than -360 degrees / second), correction is performed to make the angular velocity close to a normal angular velocity (at S50 and S60 to S64). Then, by integrating the angular velocity calculated in a predetermined calculation cycle and the corrected angular velocity, the actual relative angle to which the rotating part rotates from the rotation starting angle is calculated (at S90), and the drive of the actuator is controlled according to the deviation between the target relative angle and the actual relative angle (at S100, S110).

[0011] As a result, the actuator control method also has the same effects as the above-mentioned actuator control device.

[0012] Reference numerals in parentheses attached to components and the like represent examples of corresponding relationships between components and the like described in the embodiments to be described below and specific components and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the accompanying drawings:

[0014] Figure 1 is a system configuration diagram including the actuator control device according to the first embodiment.

[0015] Figure 2 It is from Figure 1 Schematic diagram of the sensor viewed from the II direction.

[0016] Figure 3 It is a graph showing the output characteristics of the sensor.

[0017] Figure 4 : is a graph showing the relationship between the angle of the rotating part and the output value of the sensor.

[0018] Figure 5 is an explanatory diagram of feedback control performed by the actuator control device.

[0019] Figure 6 is a flowchart of the actuator control method according to the first embodiment.

[0020] Figure 7A is a timing chart showing the actual angle of the rotating part and the sensor detection angle.

[0021] Figure 7B : is a timing chart showing the angular velocity of the rotating part calculated from the sensor detection angle.

[0022] Figure 7C is a timing chart showing the angular velocity after correction.

[0023] Figure 7D is a timing diagram showing the actual relative angle and the target relative angle of the rotating part.

[0024] Figure 8A : is a timing chart showing an actual relative angle and a target relative angle of a rotating part in one example of the first embodiment.

[0025] Figure 8B : is a timing chart showing the changing timing of the target angle in one example of the first embodiment.

[0026] Figure 8C : is a timing chart showing the deviation between the target relative angle and the actual relative angle in one example of the first embodiment.

[0027] Figure 9 1 and 2 are explanatory diagrams for explaining the operation of the rotating portion before and after the target angle is changed in one example of the first embodiment.

[0028] Figure 10A 3 is a timing chart showing the actual relative angle and the target relative angle of the rotating part of the comparative example.

[0029] Figure 10B : is a timing chart showing the change time of the target angle in the comparative example.

[0030] Figure 10C 3 is a timing chart showing the deviation between the target relative angle and the actual relative angle in the comparative example.

[0031] Figure 11 It is an explanatory diagram for explaining the operation of the rotation portion before and after the target angle is changed in the comparative example.

[0032] Figure 12 is a flowchart of an actuator control method according to the second embodiment.

[0033] Figure 13 is a flowchart of an actuator control method according to the third embodiment.

[0034] Figure 14This is an explanatory diagram for explaining the reference position correction range and the noise judgment range.

[0035] Figure 15A is a timing chart showing the actual angle of the rotating part and the sensor detection angle.

[0036] Figure 15B : is a timing chart showing the angular velocity of the rotating part calculated from the sensor detection angle.

[0037] Figure 15C is a timing chart showing the angular velocity after correction.

[0038] Figure 15D is a timing diagram showing the actual relative angle and the target relative angle of the rotating part.

[0039] Figure 15E is a timing chart showing the operation of the reference position correction range marker. and

[0040] Figure 16 is a system configuration diagram including an actuator control device according to a fourth embodiment. DETAILED DESCRIPTION

[0041] Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, the same or equivalent components are denoted by the same reference numerals as each other, and the same reference numerals will be described.

[0042] (First embodiment)

[0043] The first embodiment will be described with reference to the accompanying drawings. Figure 1 As shown, the actuator control device 1 of this embodiment performs feedback control on the actuator 2 according to the angle of the rotating portion rotated by the torque of the actuator 2. In the following description, the actuator control device 1 is referred to as ECU 1 (ECU is an abbreviation for electronic control unit).

[0044] Figure 1 The actuator 2 shown in FIG is, for example, a motor. The torque of the actuator 2 is transmitted from the motor gear 3 connected to the shaft of the actuator 2 in the order of the intermediate gear 4 and the output gear 5. As a result, the control object 6 connected to the output gear 5 rotates. Figure 1 In the figure, the three gears 3, 4, and 5 are depicted separately for ease of illustration. However, in reality, the three gears 3, 4, and 5 mesh with one another. The number of gears used to transmit torque from actuator 2 to controlled object 6 is not limited to three and can be set arbitrarily. By driving actuator 2, controlled object 6 rotates 360 degrees or more. An example of such controlled object 6 is a shift drum used in a vehicle transmission system. Controlled object 6 is not limited to this, and various objects that rotate 360 ​​degrees or more can be applied.

[0045] In this embodiment, the angles of the output gear 5 and the controlled object 6 are detected by the sensor 7. In this embodiment, the output gear 5 and the controlled object 6 correspond to an example of a "rotating part". As will be described later in this embodiment, the motor gear 3 or the intermediate gear 4 may correspond to an example of a "rotating part".

[0046] Figure 2 : shows an example of the configuration of the sensor 7. Figure 2 As shown, the sensor 7 includes a magnetic field forming unit 8 that rotates with the output gear 5 and a magnetic field detector 9 disposed within the magnetic field forming unit 8. The magnetic field forming unit 8 includes a first magnet 81 and a second magnet 81, which are arranged facing each other with their center of rotation interposed therebetween; and a first yoke 83 and a second yoke 84 that connect the first magnet 81 and the second magnet 82. The first yoke 83 connects the north pole of the first magnet 81 and the north pole of the second magnet 82. The second yoke 84 connects the south pole of the first magnet 81 and the south pole of the second magnet 82. Meanwhile, the magnetic field detector 9 includes two Hall ICs (not shown) and is secured to a housing cover (not shown), etc. Each of the two Hall ICs detects the magnitude of the orthogonal magnetic flux density in the closed magnetic circuit formed by the magnetic field forming unit 8. In other words, the two Hall ICs are arranged so that the magnetic sensitive surface of one Hall IC is orthogonal to the magnetic sensitive surface of the other Hall IC. The output signals output from the two Hall ICs (hereinafter referred to as the output values ​​of the sensor 7) are input to the ECU 1.

[0047] exist Figure 3 In the figure, the output of one Hall IC is represented by solid line A, and the output of the other Hall IC is represented by solid line B. ECU 1 converts the output of one Hall IC into a sine component and the output of the other Hall IC into a cosine component to perform angle conversion using an inverse tangent calculation. As a result, the output value of sensor 7 changes linearly from 0 degrees to 360 degrees, representing the angle of the rotating part. Furthermore, by using two Hall ICs in sensor 7, the temperature characteristics of the magnet can, in principle, be eliminated through division.

[0048] like Figure 4As shown, when the angle of the rotating part changes from 0 degrees to 360 degrees, the output value of sensor 7 changes substantially linearly from a minimum value (e.g., 0.5V) to a maximum value (e.g., 4.5V). Then, each time the rotating part rotates 360 degrees (i.e., 360 degrees, 720 degrees, 1080 degrees, etc.), it returns to the minimum value. In other words, the output value of sensor 7 has an angular range that is discontinuous each time the angle of the rotating part increases by 360 degrees (in other words, the amount of change in the sensor output value according to the change in the angle of the rotating part is reversed, and there is a range of linear interruptions). In this specification, the center of the angular range in which the output value of sensor 7 has discontinuity is referred to as the "reference position."

[0049] The ECU 1 performs feedback control on the actuator 2 so that the actual relative angle of the rotating part detected by the sensor output matches the target relative angle. Figure 5 1 is an explanatory diagram for explaining PI control as an example of feedback control executed by the ECU 1 .

[0050] like Figure 5 As shown, the output signal from the sensor 7 (which detects the angle of the rotating part rotated by the actuator 2) is input to the ECU 1. The ECU 1 calculates the actual relative angle of the rotating part based on the output value of the sensor 7. In addition, the ECU 1 calculates the target relative angle of the rotating part. The calculation method of the actual relative angle and the target relative angle will be described later.

[0051] ECU 1 calculates the angular deviation between the actual relative angle of the rotating part and the target relative angle using subtractor 11. Proportional controller 12 then calculates a P term based on the angular deviation. Furthermore, integrator 13 calculates the integrated angular deviation, and integrator controller 14 calculates an I term. Adder 15 then adds the P and I terms together to calculate the current duty cycle supplied to actuator 2, thereby driving and controlling actuator 2.

[0052] Then, refer to Figure 6 Flowchart, 7A to 7D Timing diagram of Figures 8A to 8C Timing diagram of Figure 9 The actuator control method executed by the ECU 1 of the present embodiment will be described with reference to the explanatory diagram of FIG.

[0053] References to the description of the actuator control method Figures 7A to 7D An example of controlling the actuator 2 is shown. Figures 7A to 7DIn the embodiment of the present invention, at time T0, the rotating part starts rotating from the rotation starting angle of 0 degrees toward the first target angle of 500 degrees, and at time T2, the rotating part reaches the first target angle of 500 degrees. Then, at time T2, the target angle is changed to 0 degrees, the rotating part starts rotating again, and at time T4, the rotating part reaches the changed target angle of 0 degrees.

[0054] exist Figure 6 In the flowchart shown, first, in step S10, the ECU 1 calculates a target relative angle. The target relative angle is the angle used to rotate the rotating part from the rotation starting angle to the target angle. The target relative angle is calculated as the deviation between the target angle before the target angle is changed and the target angle after the target angle is changed. This calculation is performed using the equation "target relative angle" = "target angle after change" - "target angle before change." The target angle is an absolute angle relative to a predetermined position of the rotating part, serving as a reference position, and can be set to a value exceeding 360 degrees.

[0055] exist Figure 7D In the timing diagram, the target relative angle is shown by the dotted line. At time T0, the target angle is set to 500 degrees. Here, the target angle before time T0 is set to 0 degrees. Therefore, Figure 7D As shown by the dotted line in , the target relative angle is set to 500 degrees at time T0. This is calculated by the equation "target angle after change 500 degrees" - "target angle before change 0 degrees" = "target relative angle 500 degrees".

[0056] Furthermore, the target angle becomes 0 degrees at time T2. Therefore, at time T2, the target relative angle is set to -500 degrees. This is calculated by the equation "target angle after change 0 degrees" - "target angle before change 500 degrees" = "target relative angle -500 degrees."

[0057] Next, in Figure 6 In step S20, the ECU 1 detects the output value [V] from the sensor 7, which outputs a voltage signal according to the angle of the rotating part. Figure 4 As described above, when the angle of the rotating part changes from 0 to 360 degrees, the output value of the sensor 7 changes from a minimum value to a maximum value substantially linearly. Then, each time the rotating part rotates from 0 to 360 degrees, it returns to the minimum value.

[0058] Later, in Figure 6 In step S30, the ECU 1 detects a sensor detection angle θ [degrees] by performing signal processing including AD conversion on the output value from the sensor 7. The sensor detection angle is the absolute angle of the rotating part detected by performing signal processing on the output value of the sensor 7, and is detected every predetermined calculation cycle (for example, every several milliseconds).

[0059] exist Figure 7A In the timing diagram, the actual angle of the rotating part is shown by the dotted line, and the sensor detection angle is shown by the solid line. As the rotating part rotates, the actual angle of the rotating part changes from 0 degrees to 500 degrees from time T0 to time T2. Furthermore, from time T2 to time T4, it changes from 500 degrees to 0 degrees.

[0060] On the other hand, since the sensor detection angle is detected by signal processing the output value of sensor 7, each time the output value of sensor 7 passes the reference position, the output value of sensor 7 becomes 0 degrees. Therefore, at time T1 when the output value of sensor 7 passes the reference position, the sensor detection angle changes from 360 degrees to 0 degrees. Furthermore, at time T3 when the output value of sensor 7 passes the reference position, the sensor detection angle changes from 0 degrees to 360 degrees.

[0061] Next, in Figure 6 In step S40, the ECU 1 calculates the angular velocity [degrees / second] of the rotating part by performing a temporal differentiation (i.e., dθ / dt) on the amount of change in the sensor detection angle. Specifically, the ECU 1 can detect the angular velocity of the rotating part by subtracting the sensor detection angle detected one calculation cycle ago (i.e., the previous value of θ) from the predetermined sensor detection angle θ. The angular velocity is calculated using the equation: dθ / dt = "θ" - "previous value of θ." Similar to the sensor detection angle, the angular velocity can also be calculated every predetermined calculation cycle (e.g., several milliseconds).

[0062] Figure 7B The timing diagram shows the angular velocity of the rotating part calculated by time differentiation of the change in the sensor detection angle. Figure 7B In the example, at time T1, the angular velocity decreases sharply. Moreover, even at time T3, the angular velocity increases rapidly. This is because, as Figure 7A As shown, the sensor detection angle, which is the basis for calculating the angular velocity, changes significantly between time T1 and time T3.

[0063] Next, in Figure 6 In step S50, the ECU 1 determines whether the angular velocity is equal to or greater than a first threshold value or whether the angular velocity is equal to or less than a second threshold value. The first threshold value is set to a predetermined value greater than 0 and less than 360 [degrees / second]. On the other hand, the second threshold value is set to a predetermined value less than 0 and greater than -360 [degrees / second]. Depending on the output of the actuator 2, the gear ratio, etc., the first threshold value and the second threshold value are set within a range of angular velocities that are not within the actual range. Figure 7B In the example, the first threshold is set to 70 degrees / second, and the second threshold is set to -70 degrees / second, for example.

[0064] exist Figure 6 In the determination of step S50, when the angular velocity is equal to or greater than the first threshold value or when the angular velocity is equal to or less than the second threshold value (ie, when an affirmative determination is made in step S50), the processing proceeds to step S60.

[0065] In step S60, the ECU 1 corrects the angular velocity so that it approaches the normal angular velocity. In the first embodiment, as correction to bring the angular velocity closer to the normal angular velocity, when the angular velocity is equal to or greater than a first threshold, the angular velocity equal to or greater than the first threshold is corrected by subtracting 360 degrees / second. As a result, the angular velocity equal to or greater than the first threshold can be brought closer to the normal angular velocity.

[0066] On the other hand, when the angular velocity is equal to or less than the second threshold, the angular velocity equal to or less than the second threshold is corrected by adding 360 degrees / second. As a result, the angular velocity equal to or less than the second threshold can be made closer to the normal angular velocity.

[0067] On the other hand, in the determination of step S50 , when the angular velocity is smaller than the first threshold value or when the angular velocity is larger than the second threshold value (ie, when a negative determination is made in step S50 ), the angular velocity is handled as a normal angular velocity.

[0068] Figure 7C The timing chart of shows the corrected angular velocity. The corrected angular velocity shows a substantially constant value, for example, 10 degrees / second, from time T0 to time T2, and shows a substantially constant value, for example, -10 degrees / second, from time T2 to time T4.

[0069] exist Figure 6 In the case of a negative determination in step S50 , after the correction processing in step S60 is performed, the process proceeds to step S70 .

[0070] In step S70, the ECU 1 determines whether the target angle has changed while the rotating part is rotating toward the target relative angle. If the target angle has changed in the determination of step S70 (i.e., in the case of a positive determination in step S70), the process proceeds to step S80. The process of step S80 will be described later.

[0071] On the other hand, when the target angle has not changed in the determination of step S70 (ie, in the case of a negative determination in step S70 ), the process proceeds to step S90 .

[0072] In step S90, the ECU 1 calculates the actual relative angle. The actual relative angle is the angle by which the rotating part rotates relative to the rotation starting angle. The actual relative angle is calculated by integrating the angular velocity. Specifically, the ECU 1 calculates the actual relative angle by integrating the angular velocity calculated every predetermined calculation period (e.g., several milliseconds) with the corrected angular velocity.

[0073] Subsequently, in step S100, the ECU 1 calculates the deviation between the actual relative angle of the rotating part and the target relative angle. Then, in step S110, the ECU 1 calculates the operation amount of the actuator 2 and performs feedback control on the drive of the actuator 2. The processing of steps S100 and S110 corresponds to the reference Figure 5 An example of feedback control is described.

[0074] exist Figure 7D In the timing diagram, the actual relative angle of the rotating part is represented by a solid line, and the target relative angle is represented by a dashed line. The actual relative angle of the rotating part gradually increases from 0 degrees from time T0 to time T2, and matches the initial target relative angle of 500 degrees at time T2. Then, at time T2, the target relative angle is changed to -500 degrees. If the target angle is changed after the actual and target relative angles match, the actual relative angle is reset to 0 degrees. The actual relative angle of the rotating part gradually decreases from 0 degrees from time T2 to time T4, and matches the changed target relative angle of -500 degrees at time T4.

[0075] Next, the above Figure 6 The process of step S80.

[0076] When the target angle changes while the rotating portion rotates toward the target relative angle (ie, when an affirmative determination is made in step S70 ), the ECU 1 resets the actual relative angle to (0−a).

[0077] Here, a is the angle deviation calculated by the equation "target relative angle before change" - "actual relative angle when target angle is changed".

[0078] The actual relative angle after reset is calculated by the equation "actual relative angle after reset" = 0 - ("target relative angle before change" - "actual relative angle when target angle changes"). When this formula is expanded, the equation "actual relative angle after reset" = "actual relative angle when target angle changes" - "target relative angle before change" is obtained. Therefore, when the target angle changes while the rotating part rotates toward the target relative angle, the ECU 1 resets the actual relative angle to a value obtained by subtracting the "target relative angle before change" from the "actual relative angle when target angle changes". Figures 8A to 8C and Figure 9 State the reason.

[0079] exist Figure 8A In the timing diagram of , the target relative angle of the rotating part is represented by a dot-dashed line, while the actual relative angle is represented by a solid line. Figure 8A In FIG. 1 , it is assumed that the target angle before time T10 is 0 degrees, the target angle is set to 45 degrees at time T10, and the target angle is changed to 100 degrees at time T11. Figure 8A As shown by the dot-dash line in FIG, the initial target relative angle is set to 45-0 = 45 degrees at time T10, and the changed target relative angle is set to 100-45 = 55 degrees at time T11. Therefore, the target relative angle is 45 degrees from time T10 to time T11, and is 55 degrees from time T11 to time T12.

[0080] After time T10, the rotating unit rotates from the rotation starting angle of 0 degrees to the initial target relative angle of 45 degrees, but in the middle of the rotation operation, at time T11, the target angle changes. Therefore, at time T11, the actual relative angle of the rotating unit has not yet reached the first target relative angle of 45 degrees. At this time T11, the angle deviation obtained by subtracting the "actual relative angle at time T11 when the target angle changes" from the "initial target relative angle of 45 degrees" is Figure 8A Indicated by double arrow a.

[0081] As described above, when the target angle changes while the rotating portion rotates toward the initial target relative angle of 45 degrees, the ECU 1 resets the actual relative angle to (0-a). Figure 8B The timing diagram of shows that the target angle changes at time T11. Figure 8A In the timing diagram of FIG, at time T11, the actual relative angle of the rotating part is reset to -a. Then, the actual relative angle of the rotating part gradually increases from -a reset at time T11 to the changed target relative angle of 55 degrees, and reaches the changed target relative angle of 55 degrees at time T12.

[0082] Figure 8C The timing diagram shows the deviation between the target relative angle and the actual relative angle (calculated by the equation "target relative angle" - "actual relative angle"). At time T10, the deviation is 45 degrees. After time T11, the deviation gradually decreases. Then, at time T11 when the target angle changes, the deviation changes from a to (55 + a). Thereafter, the deviation gradually decreases and becomes 0 at time T12.

[0083] Figure 9 8A to 8C are schematic diagrams showing actual operation of the rotating portion based on the control described. Figure 9The arrow M1 in the figure indicates the amount of rotation of the rotating part between time T10 and time T11, and the arrow M2 indicates the amount of rotation of the rotating part between time T11 and time T12. As shown by the arrow M1, at time T11, the rotating part has not yet reached the initial target angle of 45 degrees. Therefore, the ECU 1 performs a process of resetting the actual relative angle to (0-a) at time T11. Then, after time T11, the ECU 1 performs feedback control on the rotating part so that the rotating part rotates by an angle obtained by combining the remaining deviation a with the changed target relative angle. Therefore, as shown by the arrow M2, the rotating part can reach the changed target angle. In this way, when the target angle changes while the rotating part rotates toward the target relative angle, the ECU 1 resets the actual relative angle to (0-a). Therefore, the deviation a when the target angle changes can be absorbed by feedback control, and the rotating part can reach the target angle.

[0084] For comparison with the control process executed by the ECU 1 of the above-described first embodiment, a control process executed by the ECU of the comparative example will be described.

[0085] Figures 10A to 10C and Figure 11 1 is a diagram for explaining a control process executed by the ECU of the comparative example when the target angle changes while the rotating portion rotates toward the target relative angle.

[0086] The ECU of the comparative example performs processing for resetting the actual relative angle to 0 when the target angle changes while the rotating portion rotates toward the target relative angle.

[0087] exist Figure 10A In the timing diagram of , the target relative angle of the rotating part is represented by a dot-dashed line, while the actual relative angle is represented by a solid line. Figure 10A In FIG. 1 , it is assumed that the target angle before time T20 is 0 degrees, the target angle is set to 45 degrees at time T20, and the target angle is changed to 100 degrees at time T21. Figure 10A As shown by the dot-dash line in FIG, the initial target relative angle is set to 45 degrees at time T20, and the target relative angle after the change is set to 55 degrees at time T21. Therefore, the target relative angle is 45 degrees from time T20 to time T21, and is 55 degrees from time T21 to time T22.

[0088] After time T20, the rotating unit rotates from the rotation start angle of 0 degrees to the initial target relative angle of 45 degrees, but the target angle changes at time T21 in the middle of the rotation operation. As described above, when the rotating unit rotates toward the initial target relative angle of 45 degrees while the target angle changes, the ECU according to the comparative example resets the actual relative angle to 0. Figure 10BThe timing diagram shows that the target angle changes at time T21. Figure 10A In the timing chart of FIG, at time T21, the actual relative angle of the rotating part is reset to 0. Then, the actual relative angle of the rotating part gradually increases from 0 reset at time T21 toward the changed target relative angle of 55 degrees, and reaches the changed target relative angle of 55 degrees at time T22.

[0089] Figure 10C The timing diagram shows the deviation between the target relative angle and the actual relative angle (calculated using the equation "target relative angle" - "actual relative angle"). At time T20, the deviation is 45 degrees. After time T21, the deviation gradually decreases. Then, at time T21 when the target angle changes, the deviation changes from α to 55 degrees. Thereafter, the deviation gradually decreases and becomes 0 at time T22.

[0090] Figure 11 10A to 10C are schematic diagrams illustrating actual operation of the rotating portion based on the control described with reference to FIG. 10A to 10C . Figure 11 Arrow M3 in FIG. 2 indicates the amount of rotation of the rotating component between time T20 and time T21, and arrow M4 indicates the amount of rotation of the rotating component between time T21 and time T22. As indicated by arrow M3, at time T21, the rotating component has not yet reached the initial target angle of 45 degrees, and a deviation remains. However, because the ECU of the comparative example performs processing to reset the actual relative angle to 0 at time T21, the deviation between the target relative angle and the actual relative angle is 55 degrees. Therefore, after time T21, the deviation between the target relative angle and the actual relative angle gradually decreases due to feedback control. Even after time T22, when this deviation reaches 0, the deviation α between the actual angle of the rotating component and the changed target angle of 100 degrees remains at the time of the target angle change. Therefore, as indicated by arrow M4, the rotating component has not yet reached the changed target angle. In this way, in the control process executed by the ECU of the comparative example, when the target angle changes while the rotating component rotates toward the initial target relative angle, the rotating component cannot reach the changed target angle. That is, in the comparative example, the deviation a when the target angle is changed cannot be absorbed by the feedback control.

[0091] Compared with the ECU of the comparative example described above, the ECU 1 of the first embodiment has the following effects.

[0092] (1) In the first embodiment, when the target angle changes while the rotating part rotates toward the target relative angle before the change, the ECU 1 sets the value obtained by subtracting the "target relative angle before the change" from the "actual relative angle when the target angle changes" as the actual relative angle after reset.

[0093] As a result, when the target angle changes while the rotating portion rotates toward the target relative angle before change, the actuator 2 can be feedback-controlled to correct a deviation between the actual relative angle when the target angle changes and the target relative angle before change.

[0094] (2) In the first embodiment, the ECU 1 calculates the angular velocity of the rotating part based on the amount of change in the sensor detection angle during a predetermined calculation cycle. When the angular velocity is equal to or greater than a first threshold value, or when the angular velocity is equal to or less than a second threshold value, correction is performed to bring the angular velocity closer to a normal angular velocity. The actual relative angle to which the rotating part has rotated from the rotation start angle is calculated by integrating the angular velocity calculated during the predetermined calculation cycle and the corrected angular velocity. The drive of the actuator 2 is feedback-controlled based on the deviation between the target relative angle and the actual relative angle.

[0095] As a result, when the output value of sensor 7 passes through the reference position, ECU 1 can perform corrections to bring the angular velocity closer to the normal angular velocity. Then, by using the corrected angular velocity for angular velocity integration, ECU 1 can continuously and accurately calculate the actual relative angle even when the output value of sensor 7 passes through the reference position. Consequently, ECU 1 can continuously and accurately control the feedback of actuator 2.

[0096] (3) Specifically, in the first embodiment, when the angular velocity is equal to or greater than a first threshold value, the ECU 1 performs a correction by subtracting 360 degrees / second from the angular velocity that is equal to or greater than the first threshold value. On the other hand, when the angular velocity is equal to or less than a second threshold value, the ECU 1 performs a correction by adding 360 degrees / second to the angular velocity that is equal to or less than the second threshold value.

[0097] As a result, when the reference position of the output value of the sensor 7 is at 360 degrees, the ECU 1 can correct the angular velocity to approach the normal angular velocity when the output value of the sensor 7 passes through the reference position.

[0098] (Second embodiment)

[0099] The second embodiment will be described. The second embodiment differs from the first embodiment in that a portion of the actuator control method executed by the ECU 1 is changed from the first embodiment, and the other portions are the same as those of the first embodiment. Only the different portions will be described below.

[0100] Figure 12 The flowchart of FIG. 1 shows the actuator control method in the second embodiment. Figure 12 As shown, in the control method of the second embodiment, the processing of step S61 is different from the processing described in the first embodiment. On the other hand, the processing of steps S10 to S50 and steps S70 to S110 are the same as those of the first embodiment.

[0101] In the determination of step S50 of the second embodiment, when the angular velocity is equal to or greater than the first threshold or when the angular velocity is equal to or less than the second threshold (ie, when step S50 makes an affirmative determination), the process proceeds to step S61.

[0102] In step S61, the ECU 1 corrects the angular velocity to bring it closer to the normal angular velocity. In the second embodiment, as a correction to bring the angular velocity closer to the normal angular velocity, when the angular velocity is equal to or greater than a first threshold value or less than a second threshold value, the ECU 1 performs the following correction to change the angular velocity to the angular velocity calculated one or more calculation cycles prior, where the angular velocity was less than the first threshold value or equal to or greater than the second threshold value. The angular velocity calculated one or more calculation cycles prior is the angular velocity when the angular velocity was substantially constant. This can bring the angular velocity equal to or greater than the first threshold value or the angular velocity equal to or less than the second threshold value closer to the normal angular velocity.

[0103] Also in the above-described second embodiment, when the output value of the sensor 7 passes through the reference position, the ECU 1 may perform correction to bring the angular velocity closer to the normal angular velocity.

[0104] By correcting the angular velocity in this manner, the ECU 1 can perform correction to bring the angular velocity close to the normal angular velocity not only when the output value of the sensor 7 passes through the reference position but also when noise is added to the output value of the sensor 7 .

[0105] (Third embodiment)

[0106] The third embodiment will be described. The third embodiment differs from the first embodiment in that a portion of the actuator control method executed by the ECU 1 is changed from the first embodiment, and the other portions are the same as those of the first embodiment. Only the different portions will be described below.

[0107] Will refer to Figure 13 Flowchart, Figure 14 Illustration of Figures 15A to 15E The actuator control method according to the third embodiment is described with reference to a timing chart of FIG.

[0108] like Figure 13 As shown, in the control method of the third embodiment, the processing of steps S62 to S64 is different from that of the first embodiment, etc. On the other hand, the processing of steps S10 to S50 and steps S70 to S110 is the same as that of the first embodiment, etc.

[0109] In the determination of step S50 of the third embodiment, when the angular velocity is equal to or greater than the first threshold or when the angular velocity is equal to or less than the second threshold (ie, affirmative determination is made in step S50 ), the process proceeds to step S62 .

[0110] In step S62, ECU 1 determines whether the sensor detection angle is within a predetermined angle range. The predetermined angle range includes an angle range in which the sensor output value does not have continuity (i.e., a linear interruption in an ideal waveform). The predetermined angle range is also referred to as a "reference position correction range". The determination in step S62 is then performed by determining whether the reference position correction range mark is "1" or "0". When the reference position correction range mark is "1", the sensor detection angle is within the predetermined angle range. On the other hand, when the reference position correction range mark is "0", the sensor detection angle is not within the predetermined angle range.

[0111] exist Figure 14 In the explanatory diagram of , hatching is added to the predetermined angle range (i.e., the reference position correction range) determined in step S62. When using a sensor 7 whose reference position is 0 degrees (i.e., 360 degrees), the reference position correction range is set to, for example, a range of ±5 degrees from the reference position. In this case, when the rotating part rotates in the forward direction, the sensor detection angle is greater than 355 degrees and the reference position correction range is marked as "1", and the sensor detection angle is greater than 5 degrees and the reference position correction range is marked as "0". On the other hand, when the rotating part rotates in the reverse direction, the sensor detection angle is less than 5 degrees and the reference position correction range is marked as "1", and the sensor detection angle is less than 355 degrees and the reference position correction range is marked as "0". The range outside the reference position correction range is referred to as the noise determination range.

[0112] If in Figure 13 If the reference position correction range flag is determined to be "1" (i.e., the sensor detection angle is within the reference position correction range) in step S62, the process proceeds to step S63. In this case, since the sensor detection angle is within the reference position correction range, it is considered that the output value of the sensor 7 passes the reference position.

[0113] In step S63, the ECU 1 performs the same processing as step S60 described in the first embodiment. Specifically, when the angular velocity is equal to or greater than the first threshold, the angular velocity is corrected by subtracting 360 degrees / second. As a result, angular velocities equal to or greater than the first threshold can be brought closer to normal angular velocities. On the other hand, when the angular velocity is equal to or less than the second threshold, the angular velocity is corrected by adding 360 degrees / second. As a result, angular velocities equal to or less than the second threshold can be brought closer to normal angular velocities.

[0114] If in Figure 13If the reference position correction range flag is determined to be "0" in step S62 (i.e., the sensor detection angle is not within the reference position correction range), the process proceeds to step S64. In this case, since the sensor detection angle is not within the reference position correction range, it is considered that noise is included in the output value of the sensor 7.

[0115] In step S64, the ECU 1 performs the same processing as step S61 described in the second embodiment. Specifically, when the angular velocity is equal to or greater than the first threshold value or equal to or less than the second threshold value, correction is performed to replace the angular velocity calculated one or more calculation cycles prior, where the angular velocity was less than the first threshold value or greater than the second threshold value. The angular velocity calculated one or more calculation cycles prior is the angular velocity when the angular velocity was substantially constant. This allows the angular velocity, which is equal to or greater than the first threshold value or equal to or less than the second threshold value, to be closer to the normal angular velocity.

[0116] exist Figure 15A In the timing diagram, the dotted line represents the actual angle of the rotating part, and the solid line represents the sensor detection angle. Furthermore, the reference position (i.e., 360 degrees) is indicated by the dotted line. As the rotating part rotates, the actual angle of the rotating part increases continuously from time T30 to time T39.

[0117] On the other hand, the sensor detection angle changes dramatically around time T34. This change around time T34 is due to noise added to the sensor output. Furthermore, when the output value of sensor 7 passes the reference position (i.e., 360 degrees), the sensor detection angle changes from 360 degrees to 0 degrees around time T37.

[0118] Figure 15B The timing diagram shows the angular velocity of the rotating part calculated by time differentiation of the change in the sensor detection angle. Figure 15B In the example, the angular velocity increases and decreases rapidly around time T34, with the maximum value of the angular velocity being equal to or greater than the first threshold value, and the minimum value of the angular velocity being equal to or less than the second threshold value. Furthermore, around time T37, the angular velocity decreases sharply, and the minimum value of the angular velocity is equal to or less than the second threshold value.

[0119] The correction described in step S63 or step S64 is Figure 15B The angular velocity is shown as part of the execution. Figure 15E As shown in FIG. 1 , the reference position correction range flag is “0” around time T34. Figure 15BThe angular velocity around time T34 in step S64 is corrected. That is, the ECU 1 performs correction in which the angular velocity above the first threshold or below the second threshold is replaced with the angular velocity calculated one or more calculation cycles ago, where the angular velocity is less than the first threshold or greater than the second threshold.

[0120] In addition, if Figure 15E As shown in FIG. 1 , the reference position correction range flag is “1” around time T37. Figure 15B The angular velocity around time T37 in step S63 is corrected. That is, the ECU 1 corrects the angular velocity equal to or less than the second threshold value by adding 360 [degrees / second].

[0121] Figure 15C The timing chart of FIG. 1 shows the corrected angular velocity. The corrected angular velocity exhibits a substantially constant value, for example, 10 degrees / second, from time T30 to time T39.

[0122] exist Figure 15D In the timing diagram, the actual relative angle of the rotating part is represented by a solid line, and the target relative angle is represented by a dotted line. The actual relative angle of the rotating part gradually increases from 0 degrees from time T30 to time T39, and coincides with the target relative angle of 500 degrees at time T39.

[0123] In the third embodiment described above, when the sensor output value has a sensor detection angle within a predetermined angular range in which the sensor output value has no continuity and an angular velocity equal to or greater than a first threshold value, the ECU 1 performs correction by subtracting 360 degrees from the angular velocity equal to or greater than the first threshold value. On the other hand, when the sensor output value has a sensor detection angle within a predetermined angular range in which the sensor output value has no continuity and an angular velocity equal to or less than a second threshold value, the ECU 1 performs correction by adding 360 degrees to the angular velocity equal to or less than the second threshold value.

[0124] As a result, when the reference position of the output value of the sensor 7 is at 360 degrees, the ECU 1 can correct the angular velocity to approach the normal angular velocity when the output value of the sensor 7 passes through the reference position.

[0125] On the other hand, when the sensor output value has a sensor detection angle outside a predetermined angle range in which the sensor output value does not have continuity and the angular velocity is equal to or greater than the first threshold value or equal to or less than the second threshold value, the ECU 1 performs correction to replace the angular velocity with the angular velocity calculated one or several calculation cycles before, wherein the velocity is less than the first threshold value or greater than the second threshold value.

[0126] As a result, when the output value of the sensor 7 contains noise, the angular velocity at that time can be corrected to be close to the normal angular velocity.

[0127] (Fourth embodiment)

[0128] In the fourth embodiment, a part of the structure of the ECU 1 is changed from the first embodiment, and the other parts are similar to the first embodiment, so only the differences from the first embodiment will be described.

[0129] like Figure 16 As shown, in the fourth embodiment, sensor 7 detects the angle of intermediate gear 4. In the fourth embodiment, intermediate gear 4 corresponds to an example of a "rotating portion." Intermediate gear 4 also rotates over 360 degrees. ECU 1 can control the driving of actuator 2 based on the angle of intermediate gear 4.

[0130] When this system is applied to, for example, the drive control of a shift drum in a vehicle transmission system, it may be difficult to arrange the sensor 7 in the output gear 5 due to vehicle installation restrictions. Even in this case, in the fourth embodiment, the installation restrictions can be alleviated by arranging the sensor 7 in the intermediate gear 4.

[0131] When sensor 7 is placed in intermediate gear 4, the sensor detection angle becomes larger in proportion to the gear reduction ratio when the control target is manipulated at the same angle, compared to when sensor 7 is placed in output gear 5. Therefore, due to the increased resolution, feedback control of actuator 2 can be performed more accurately.

[0132] (Other embodiments)

[0133] (1) In the above embodiments, the shift drum used in the vehicle transmission system is used as the control object 6. However, the control object 6 is not limited thereto and can be applied to various objects that rotate 360 ​​degrees or more.

[0134] (2) In each of the above embodiments, sensor 7 includes magnetic field forming unit 8 having two magnets and two yokes, and magnetic field detecting unit 9 disposed within magnetic field forming unit 8. However, the present invention is not limited thereto. As sensor 7, any sensor 7 having various structures, including those described in Patent Document 1, may be employed as long as it can detect the angle of the rotating portion.

[0135] (3) In the above embodiments, the sensor 7 detects the angle of the output gear 5 or the intermediate gear 4, but the invention is not limited thereto. The sensor 7 may detect the angle of the motor gear 3. In this case, the motor gear 3 is an example of a "rotating portion".

[0136] (4) In the above-described embodiments, PI control has been described as an example of feedback control performed by the ECU 1, but the feedback control is not limited thereto, and various methods such as PID control or P control may be employed.

[0137] The present disclosure is not limited to the above-mentioned embodiments and can be appropriately modified. The above-mentioned embodiments are not independent of each other and can be appropriately combined, except when it is obviously impossible to combine. Unless it is specifically stated that the elements or features described in the foregoing description are indispensable, or unless the elements or features are obviously indispensable in principle, the various elements or features of a particular embodiment are not necessarily indispensable. In addition, in each of the above-mentioned embodiments, when citing numerical values ​​such as the numbers, values, quantities, ranges, etc. of the constituent elements of the embodiment, except where the numerical values ​​are clearly indispensable and where the numerical values ​​are obviously limited to specific numbers in principle, the present disclosure is not limited to specific numbers. In addition, in each of the above-mentioned embodiments, when mentioning the shape, positional relationship, etc. of parts, etc., except where the parts are specifically defined and where the parts are fundamentally limited to specific shapes, positional relationships, etc., they are not limited to the shape, positional relationship, etc.

[0138] The control device and technology according to the present disclosure can be implemented by a special-purpose computer, which is provided by constituting a processor and a memory, and the processor and the memory are programmed to perform one or more functions implemented by a computer program. Alternatively, the control device and technology according to the present disclosure can be implemented by a special-purpose computer provided by constituting a processor with one or more special-purpose hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure are based on a combination of a processor and a memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It can be implemented by one or more configured special-purpose computers. The computer program can be stored in a tangible, non-transitory computer-readable storage medium as an instruction to be executed by a computer.

[0139] Note that the flowcharts or process flow diagrams herein include sections (also referred to as steps), each section being represented, for example, as S1. Furthermore, each section may be divided into several subsections, and several sections may be combined into a single section. Furthermore, each such configured section may also be referred to as a device, module, or apparatus.

[0140] Although the present disclosure has been described with reference to its embodiments, it should be understood that the present disclosure is not limited to these embodiments and configurations. The present disclosure is intended to cover various modifications and equivalent arrangements. In addition, although various combinations and configurations are provided, other combinations and configurations including more, fewer, or only a single element are also within the spirit and scope of the present disclosure.

Claims

1. An actuator control device that controls driving of an actuator according to the angle of a rotating portion driven by the actuator and capable of rotating 360 degrees or more, the actuator control device comprising: A processor configured to: calculating a target relative angle for rotating the rotating part from a rotation starting angle to a target angle (S10); detecting a sensor detection angle as an absolute angle of the rotating part by performing signal processing on an output value from a sensor (7), wherein the sensor outputs an output signal corresponding to the angle of the rotating part (S20 and S30); calculating an angular velocity of the rotating part based on a change amount of the sensor detection angle in a predetermined calculation cycle (S40); When the angular velocity is greater than or equal to a first threshold value, or when the angular velocity is less than or equal to a second threshold value, correcting the angular velocity to be closer to a normal angular velocity (S50 and S60 to S64), wherein the first threshold value is less than 360 degrees / second and greater than 0 degrees / second, and the second threshold value is less than 0 degrees / second and greater than -360 degrees / second; calculating an actual relative angle to which the rotating part rotates from the rotation starting angle by integrating the angular velocity calculated in the predetermined calculation period and the corrected angular velocity (S90); and The driving of the actuator is feedback-controlled according to a deviation between a target relative angle and the actual relative angle ( S100 , S110 ).

2. The actuator control device according to claim 1, wherein: The processor is configured to: When the angular velocity is equal to or greater than the first threshold value, correcting the angular velocity by subtracting 360 degrees / second from the angular velocity; and When the angular velocity is equal to or less than the second threshold, the angular velocity is corrected by increasing the angular velocity by 360 degrees / second (S60).

3. The actuator control device according to claim 1, wherein: The processor is configured to: When the angular velocity is equal to or greater than the first threshold or equal to or less than the second threshold, the angular velocity is corrected by replacing the angular velocity with another angular velocity calculated one or several calculation cycles ago, in which the angular velocity is less than the first threshold or greater than the second threshold (S62).

4. The actuator control device according to claim 1, wherein: The processor is configured to: calculating the target relative angle as a deviation between the target angle before the target angle is changed and the target angle after the target angle is changed; When the target angle changes, resetting the actual relative angle; and When the target angle changes while the rotating part rotates toward the target relative angle before the target angle changes, the value obtained by subtracting the target relative angle before the target angle changes from the actual relative angle when the target angle changes is set as the actual relative angle after resetting the actual relative angle (S70, S80).

5. The actuator control device according to any one of claims 1 to 4, wherein: The processor is configured to: correcting the angular velocity by subtracting 360 degrees / second from the angular velocity when the angular velocity is equal to or greater than the first threshold value and the sensor detection angle is within a predetermined angle range within which the output value from the sensor does not have continuity; when the angular velocity is equal to or less than the second threshold value and the sensor detection angle is within a predetermined angle range in which the output value from the sensor does not have continuity, correcting the angular velocity by increasing the angular velocity by 360 degrees / second (S63); and When the angular velocity is equal to or greater than the first threshold value or equal to or less than the second threshold value and the sensor detection angle is outside a predetermined angle range in which the output value from the sensor does not have continuity, the angular velocity is corrected by replacing the angular velocity with another angular velocity calculated one or several calculation cycles ago, in which the angular velocity is less than the first threshold value or greater than the second threshold value (S64).

6. An actuator control method for controlling driving of the actuator according to the angle of a rotating part driven by the actuator and capable of rotating 360 degrees or more, the actuator control method comprising: calculating a target relative angle for rotating the rotating part from a rotation starting angle to a target angle (S10); detecting a sensor detection angle as an absolute angle of the rotating part by performing signal processing on an output value from a sensor (7), wherein the sensor outputs an output signal corresponding to the angle of the rotating part (S20 and S30); calculating an angular velocity of the rotating part based on a change amount of the sensor detection angle in a predetermined calculation cycle (S40); When the angular velocity is greater than or equal to a first threshold value, or when the angular velocity is less than or equal to a second threshold value, correcting the angular velocity to be closer to a normal angular velocity (S50 and S60 to S64), wherein the first threshold value is less than 360 degrees / second and greater than 0 degrees / second, and the second threshold value is less than 0 degrees / second and greater than -360 degrees / second; calculating an actual relative angle to which the rotating part rotates from the rotation starting angle by integrating the angular velocity calculated in the predetermined calculation period and the corrected angular velocity (S90); and The driving of the actuator is feedback-controlled according to a deviation between a target relative angle and the actual relative angle ( S100 , S110 ).

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