Motor control device

Abstract

To compensate for any change or replacement in a motor or a motor control unit by a motor control device alone.SOLUTION: A motor control device comprises: a motor; a motor control unit configured separately from the motor; a current detection unit for detecting a current supplied from the motor control unit; an angle detection unit for detecting a rotation of the motor; a compensation resistor arranged in parallel with the motor as an electric circuit; a switching unit for switching a current supply between the motor side and the compensation resistor side; and a compensation control unit for compensating for a change of a current value in at least one of the motor and the motor control unit. The compensation control unit performs a compensation resistor zero point compensation being a compensation of compensation resistor zero point of a current value and a compensation resistance gain compensation being a compensation of compensation resistor gain value being a difference in current values between during energization and during de-energization so as to bring a compensation resistor monitor current value based on a measured value closer to a compensation resistance theoretical current value being a calculated value on the basis of the detected current from the current detection unit when the compensation resistor is energized and when de-energized.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a motor control device, the motor being suitable for use in an automobile, and useful, for example, in a haptic device that vibrates an accelerator pedal to communicate information to an occupant. [Background technology]

[0002] Patent Document 1 discloses a torque correction method for generating an appropriate torque in a motor control device regardless of individual differences between motors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-61453 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the motor and the motor control device are combined and inspected, and then shipped as is. For this reason, it is necessary for the motor device to be an electromotive integrated device. However, the motor is not necessarily an electromotive integrated device. In addition, the motor and the motor control device may change over time, and the motor and the motor control device may need to be replaced.

[0005] The present disclosure assumes a case where a change occurs in the motor and the motor control device, or where at least one of the motor and the motor control device is replaced, and aims to make it possible to correct the change by the motor control device alone, without using an external inspection device. [Means for solving the problem]

[0006] The first aspect of the present disclosure is a motor control device including a motor that rotates when supplied with current, a motor control unit configured separately from the motor and controlling the rotation of the motor, a current detection unit that detects the current supplied from the motor control unit, an angle detection unit that detects the rotation of the motor, a correction resistor arranged in parallel with the motor in terms of an electrical circuit, a switching unit that switches the supply of current between the motor side and the correction resistor side, and a correction control unit that corrects changes in the current value of at least one of the motor and the motor control unit.

[0007] The correction control unit of the first motor control device disclosed herein, with the current switched to the correction resistor by the switching unit, performs correction resistor zero point correction, which is a correction of the correction resistor zero point of the current value, and correction resistor gain correction, which is a correction of the correction resistor gain value, which is the difference between the current value when current is applied and when current is not applied, so as to bring the correction resistor monitor current value, which is based on the actual measurement value, closer to the correction resistor theoretical current value, which is a calculated value, based on the detected current from the current detection unit when current is applied to the correction resistor and the detected current from the current detection unit when current is not applied to the correction resistor. Since the motor control device itself is equipped with the correction resistor, it is possible to self-correct motor torque changes without using an external detection device.

[0008] The correction control unit of the second motor control device disclosed herein inputs the motor monitor zero point when no current is flowing of the motor monitor current value based on the actual motor current value when the current is switched to the motor side by the switching unit, and the motor theoretical zero point when no current is flowing of the motor theoretical current value calculated based on the correction resistance zero point, and makes corrections in the direction of reducing the offset amount, which is the difference between the motor monitor zero point and the motor theoretical zero point.

[0009] Since the motor theoretical zero point is determined in advance based on the corrected resistance zero point, by correcting the motor monitor zero point so that it coincides with the motor theoretical zero point, the offset amount can be reduced and torque variations due to motor changes can be eliminated.

[0010] The correction control unit of the third motor control device disclosed herein receives a motor monitor on / off current value, which is the difference between the motor monitor current value when current is applied and when current is not applied, and a theoretical motor on / off current value calculated based on a correction resistor gain value, and corrects the difference between the motor monitor on / off current value and the theoretical motor on / off current value in a direction to reduce the difference. Since the theoretical motor on / off current value is calculated based on the correction resistor gain value, it is possible to self-correct motor torque changes.

[0011] The correction control unit of the fourth motor control device of the present disclosure calculates the deterioration based on a signal from the angle detection unit, and corrects the change when the deterioration calculated is equal to or greater than a predetermined level. By detecting the deterioration of the motor using a method other than the change, the timing of correction at the time of the change can be changed according to the level of the deterioration of the motor. This makes it possible to more appropriately time the correction of the change.

[0012] A correction control unit of a fifth motor control device of the present disclosure uses a theoretical angular velocity of the motor under no load, calculated using an electromotive force constant determined by the motor specifications and a back electromotive force when the motor is energized, and an actual angular velocity of the motor detected by an angle detection unit, and determines deterioration when the difference between the theoretical angular velocity and the actual angular velocity becomes a predetermined value or more, and corrects the change. In the fifth motor control device of the present disclosure, deterioration can be determined based on the difference between the theoretical angular velocity and the actual angular velocity.

[0013] The correction control unit of the sixth motor control device of the present disclosure distinguishes between multiple levels of deterioration and changes the frequency of correction of the change according to the level of deterioration. By correcting the change according to the deterioration rank of the motor, correction can be performed at an appropriate timing.

[0014] The correction control unit of the seventh motor control device of the present disclosure detects a motor failure based on a signal from the angle detection unit, and when a failure is detected, determines that the motor is abnormal. It is possible to ensure safety by stopping the operation of the motor when a failure occurs.

[0015] The correction control unit of the eighth motor control device disclosed herein detects a fault when the maximum angular velocity and maximum angular acceleration while the motor is energized are equal to or less than a predetermined value, and the cumulative angular displacement while the motor is energized is equal to or less than a predetermined value. Since the determination is based on the maximum angular velocity, maximum angular acceleration, and cumulative angular displacement, the fault can be detected more accurately.

[0016] The motor of the ninth motor control device of the present disclosure is an automobile motor, and the correction control unit corrects the change when the automobile is stopped. The correction of the change does not hinder the original use of the motor.

[0017] The correction control unit of the tenth motor control device of the present disclosure corrects the change when the following conditions are satisfied: the vehicle speed is zero; the accelerator pedal opening is zero; the shift position is either the parking range or the neutral range; the parking brake is on; and the angle detection unit is not detecting the rotation of the motor. The correction of the change does not impede the use of the motor.

[0018] The motor of the eleventh motor control device of the present disclosure is used in a haptic device that transmits information to a passenger by vibrating an accelerator pedal. The motor is used in an automobile, and can intuitively transmit information about the speed of the automobile to the passenger via the accelerator pedal. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a configuration diagram showing an example of how the motor is used. [Diagram 2] FIG. 2 is an electric circuit diagram of the motor control device. [Diagram 3] FIG. 3 is another example of an electric circuit diagram of the motor control device. [Figure 4] FIG. 4 is a diagram showing the correction by the correction control unit in a state in which the current is switched to the correction resistor side by the switching unit. [Diagram 5] FIG. 5 is a diagram showing the correction by the correction control unit in a state where the switching unit switches to the motor side. [Figure 6] FIG. 6 is a diagram showing detection of motor deterioration. [Figure 7] FIG. 7 is a flowchart showing the correction requirement determination. [Figure 8] FIG. 8 is a table showing the deterioration ranks. [Figure 9] FIG. 9 is a flowchart showing the correction execution determination. [Figure 10A] FIG. 10A is a flowchart showing a determination as to whether or not to perform motor deterioration detection. [Figure 10B] FIG. 10B is a flowchart showing a determination as to whether or not motor deterioration detection is to be performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An example of the present disclosure will be described below with reference to the drawings. FIG. 1 shows an example in which the motor 100 is used in a haptic device 110 of an automobile. The haptic device 110 vibrates an accelerator pedal 111 to convey information to an occupant. The rotation of the motor 100 is transmitted to the accelerator pedal 111 via a transmission mechanism 112, causing the accelerator pedal 111 to vibrate in the up-down direction. The motor 100 can be rotated in a fixed direction to vibrate the accelerator pedal 111 via the transmission mechanism 112, or the motor 100 can be rotated forward and backward to vibrate the accelerator pedal 111.

[0021] Signals from various sensors 113 are input to a control circuit 114, which drives the motor 100 when necessary and vibrates the accelerator pedal to convey information to the occupant. Examples of various sensors 113 include the following. If the sensor 113 is for measuring the distance between vehicles, it vibrates the accelerator pedal 111 when the distance between the vehicle ahead falls below a predetermined distance to indicate to the occupant that the distance between the vehicles has become shorter. If the sensor 113 is for detecting vehicle speed, it vibrates the accelerator pedal 111 when the vehicle speed exceeds a predetermined speed to indicate to the occupant that the vehicle is going too fast.

[0022] If the sensor 113 detects the rotation of the tires, when it detects tire slippage, it vibrates the accelerator pedal 111 to inform the occupant that the tire is slipping. If the sensor 113 is a camera arranged in the passenger compartment to photograph the occupant's face, when it detects that the occupant is looking away or falling asleep, it vibrates the accelerator pedal 111 to alert the occupant so that the occupant can concentrate on driving. The above are typical examples of the use of the haptic device 110, but it is also possible to inform the occupant of the acceleration state of the car, whether the car is out of the lane, etc.

[0023] The control unit 200 shown in FIG. 2 has a function of a motor control unit 200A that controls the rotation direction and rotation speed of the motor 100, and a function of a correction control unit 200B that detects changes in at least one of the motor 100 and the motor control unit 200A and corrects the changes. First, the function of the motor control unit 200A will be described. The control unit 200 is, for example, a microcomputer, and has an analog digital signal input / output function, a clock, a memory function, and a calculation function. The motor control unit 200A has a high side gate driver 201 and a low side gate driver 202, and controls an H bridge circuit 210. The H bridge circuit 210 is configured to include a PMOS transistor 211, a PMOS transistor 212, an NMOS transistor 213, and an NMOS transistor 214. A high voltage is supplied from a battery 220 to the source terminals of the PMOS transistor 211 and the PMOS transistor 212, and the source terminals of the NMOS transistor 213 and the NMOS transistor 214 are electrically connected to the ground side of the battery 220. Of course, whether a PMOS transistor or an NMOS transistor is used may be selected appropriately, and an NMOS transistor with a small on-resistance may be used on the high-voltage side of the battery 220.

[0024] The high-side gate driver 201 of the control unit 200 controls the on / off of the PMOS transistor 211 and the PMOS transistor 212, and the low-side gate driver 202 controls the on / off of the NMOS transistor 213 and the NMOS transistor 214. For example, the high-side gate driver 201 turns on the PMOS transistor 211 and turns off the PMOS transistor 212, and the low-side gate driver 202 turns off the NMOS transistor 213 and turns on the NMOS transistor 214. In this case, a current from the battery 220 is supplied to the motor 100 from the PMOS transistor 211 via the output point 215. The current flows from the motor 100 to the input point 216, and flows from the NMOS transistor 214 to the ground side of the battery 220. In this state, the motor 100 rotates forward at a rotation speed according to the current.

[0025] Conversely, the high-side gate driver 201 turns on the PMOS transistor 212 and turns off the PMOS transistor 211, and the low-side gate driver 202 turns on the NMOS transistor 213 and turns off the NMOS transistor 214. In this case, current from the battery 220 is supplied to the motor 100 from the PMOS transistor 212 via the output point 215. The current flows from the motor 100 to the input point 216, and from the NMOS transistor 213 to the ground side of the battery 220. In this state, the motor 100 rotates in the reverse direction at a rotation speed according to the current.

[0026] The function of the control unit 200 as the motor control unit 200A is to control the high side gate driver 201 and the low side gate driver 202 to rotate the motor 100 in response to a signal from the control circuit 114. In the example of the haptic device 110, it is used to generate vibration by repeating forward and reverse rotation, or to vary the degree of vibration by changing the number of rotations.

[0027] Next, the function of the control unit 200 as the correction control unit 200B will be described. The correction resistor 230 is arranged so as to be in parallel with the motor 100 in terms of the electric circuit. If possible, it is desirable that the correction resistor 230 has the same resistance value as the motor 100. However, since the resistance value of the motor 100 is usually about 2 to 4 ohms, it is not desirable to give the correction resistor 230 a resistance value corresponding to the resistance value of the motor 100, because the amount of heat generated increases and the size of the motor increases. In this example, the correction resistor 230 has a resistance value about 100 to 1000 times the resistance value of the motor 100. As a result, in this example, the size of the correction resistor 230 is suppressed, and the motor control device 260 is made smaller.

[0028] Then, the switching unit 231 switches between a state in which the current from the battery 220 flows to the motor 100 side via the H-bridge circuit 210 and a state in which the current flows to the correction resistor 230 side via the H-bridge circuit 210. As the switching unit 231, in addition to the mechanical relay shown in FIG. 2, a semiconductor relay shown in FIG. 3 is also used. In the semiconductor relay of FIG. 3, when the first transistor 232 is on and the second transistor 233 is off, the current supplied from the battery 220 via the H-bridge circuit 210 flows to the motor 100. Conversely, when the first transistor 232 is off and the second transistor 233 is on, the current supplied from the battery 220 via the H-bridge circuit 210 flows to the correction resistor 230.

[0029] The control unit 200 also receives a current value detected by the current detection unit 240. The current detection unit 240 detects the current flowing through the motor 100 or the correction resistor 230, and a detector of a shunt resistor type or a Hall sensor type is used. In the shunt resistor type, the current value is calculated according to the potential difference between resistors. In the Hall sensor type, the current value is measured according to the change in magnetic force. The control unit 200 also receives a signal from the angle detection unit 250. The angle detection unit 250 detects the rotation angle of the motor 100 based on a signal from a detector 251 such as a Hall sensor or a resolver. The Hall sensor detects the change in magnetic flux of a magnet that rotates together with the motor 100 to detect the rotation. In addition, the resolver's rotor rotates with the rotation of the motor 100, and the resolver's magnetic field detection coil detects the change in the magnetic field, thereby detecting the rotation of the motor 100.

[0030] The function of the control unit 200 as the correction control unit 200B includes correction of the motor 100 itself and correction of the motor control device 260, but an example of correcting the motor control device 260 will be described first. Fig. 4 shows the detection signal in the current detection unit 240. Fig. 4 shows a state in which the switching unit 231 has switched to the correction resistor 230 side. The dashed line in Fig. 4 shows the actual measurement value of the current that actually flows through the correction resistor 230, which is the correction resistor monitor current value 241. The solid line in Fig. 4 also shows the theoretical correction resistor current value 242, which is the theoretical value that is assumed to flow through the correction resistor 230 based on calculations.

[0031] When the high-side gate driver 201 turns off both the PMOS transistor 212 and the PMOS transistor 211, the high-side gate driver 201 is in a non-conducting state in which no power is supplied from the battery 220. In this case, the correction resistor monitor current value 241 and the correction resistor theoretical current value 242 should both be zero. However, although the correction resistor theoretical current value 242 is zero, the correction resistor monitor current value 241 does not become the zero point, and a difference occurs between the correction resistor theoretical current value 242 and the zero point, and an offset amount 243 may occur. As described above, the correction resistor monitor current value 241 should also be the zero point like the correction resistor theoretical current value 242. If the offset amount 243 occurs for some reason, first, the offset amount 243 is corrected to be reduced. Desirably, the correction resistor zero point 241A of the correction resistor monitor current value 241 is corrected to match the correction resistor zero point 242A of the correction resistor theoretical current value 242.

[0032] The correction resistor monitor current value 241 is a current value based on the current that actually flows through the correction resistor 230, and should essentially match the correction resistor theoretical current value 242. It is assumed that the offset amount 243 occurs when some change occurs in the motor control device 260, such as deterioration over time, or when the motor control device 260 is replaced.

[0033] As described above, the correction resistor monitor current value 241 and the correction resistor theoretical current value 242 are zero (correction resistor zero point 241A and correction resistor zero point 242A) when no current is applied, but rise when the H-bridge circuit 210 is operating and current is applied. Therefore, a difference (gain value) occurs between the on-time current value of the correction resistor 230 when current is applied and the off-time current value of the correction resistor 230 when current is not applied. This current value difference (correction resistor gain value) in the correction resistor monitor current value 241 is set as the correction resistor monitor on-off current value 245. Similarly, in the correction resistor theoretical current value 242, a difference (correction resistor gain value) occurs in the correction resistor theoretical on-off current value 244 between the current value when current is applied and the current value when current is not applied. And the correction resistor monitor on-off current value 245 should essentially be the same as the correction resistor theoretical on-off current value 244. However, for some reason, such as replacement of the motor control device 260, a difference may occur between the correction resistor theoretical on / off current value 244 and the correction resistor monitor on / off current value 245. In this case as well, the correction resistor gain value of the correction resistor monitor on / off current value 245 is corrected so as to match the correction resistor gain value of the correction resistor theoretical on / off current value 244.

[0034] As described above with reference to FIG. 4, first, the switching unit 231 causes the current received from the battery 220 via the H-bridge circuit 210 to flow to the correction resistor 230. Then, the correction resistor monitor current value 241 based on the actual current measurement value of the correction resistor 230 is corrected in a direction that matches the correction resistor theoretical current value 242 calculated by calculation. Specifically, first, the correction resistor zero point 241A of the correction resistor monitor current value 241 is corrected in a direction that matches the correction resistor zero point 242A of the correction resistor theoretical current value 242. Next, the correction resistor monitor on / off current value 245 is corrected in a direction that matches the correction resistor theoretical on / off current value 244. This completes the correction of the motor control device 260 alone using the correction resistor 230.

[0035] Next, an example of the correction control section 200B of the control section 200 correcting the motor 100 will be described with reference to Fig. 5. The correction function of the motor 100 is also a correction in the direction of bringing the motor monitor current value 24A based on the actually measured motor current value of the motor 100 closer to the theoretical motor current value 24B calculated by calculation. The theoretical motor current value 24B determines the theoretical motor zero point 24E using the correction resistance zero point explained in Fig. 4, and determines the theoretical motor on / off current value 24D using the correction resistance gain value.

[0036] An offset amount 24F may occur between the motor monitor current value 24A and the motor theoretical current value 24B, or a difference may occur between the motor theoretical on-off current value 24D and the motor monitor on-off current value 24C. In such a case, the correction control unit 200B corrects the motor 100 to reduce the offset amount 24F or the difference in the current value. As shown in FIG. 5A, there is a case where a deviation occurs between the current waveform of the motor theoretical current value 24B and the current waveform of the motor monitor current value 24A. In this case, as shown in FIG. 5B, the offset amount 24F is corrected to be smaller. That is, the zero point (motor monitor zero point) of the motor monitor current value 24A is corrected to match the motor theoretical zero point 24E of the motor theoretical current value 24B. As described above, the motor theoretical zero point 24E is calculated using the correction resistor zero point. Therefore, the zero point (motor monitor zero point) of the motor monitor current value 24A is corrected in a direction to reduce an offset amount 24F, which is the difference between the motor theoretical zero point 24E of the motor theoretical current value 24B calculated based on the correction resistance zero point.

[0037] As shown in FIG. 5B, even if the offset amount 24F is corrected to zero, a difference may occur between the motor theoretical on / off current value 24D and the motor monitor on / off current value 24C. This may be due to aging of the motor 100. In such a case, as shown in FIG. 5C, the difference between the motor theoretical on / off current value 24D and the motor monitor on / off current value 24C is corrected to be smaller. Specifically, the magnitude of the motor monitor on / off current value 24C of the motor monitor current value 24A is corrected to match the magnitude of the motor theoretical on / off current value 24D of the motor theoretical current value 24B. The motor theoretical on / off current value 24D is also calculated using the correction resistor gain value as described above.

[0038] However, the motor theoretical current value 24B and the motor monitor current value 24A in Fig. 5 are determined according to the resistance of the actual motor 100. On the other hand, the correction resistor theoretical current value 242 and the correction resistor monitor current value 241 are obtained according to the resistance of the correction resistor 230. As described above, the correction resistor 230 has a resistance 100 to 1000 times that of the motor 100. Therefore, there is actually a difference of 100 to 1000 times between the correction of the correction resistor 230 shown in Fig. 4 and the correction of the motor 100 shown in Fig. 5. Therefore, the calculation of the motor theoretical on / off current value 24D using the correction resistor gain value is also performed by linear approximation.

[0039] The operation of the control unit 200 as the correction control unit 200B of the motor 100 is as described above, but as described above, the function of the correction control unit 200B is required when the motor control device 260 changes due to aging deterioration or the like. However, the function of the control unit 200 as the correction control unit 200B also includes the detection of deterioration of the motor 100. That is, in this example, the motor control device 260 is first corrected to ensure that the supply current value of the motor control device 260 itself is accurate. On top of that, it is possible to correct changes due to deterioration of the motor 100, etc., on the premise that the motor control device 260 is functioning correctly. The function of detecting deterioration of the motor 100 will be described below.

[0040] The angular velocity W of the motor 100 when no load is applied is obtained by dividing the back electromotive force Ea by the electromotive force constant Ke.

[0041] W = Ea / Ke Here, the electromotive force constant Ke is determined by motor specifications such as voltage, current, and rated rotation speed. More specifically, the electromotive force constant Ke is determined by the ratio between the periodic differential value of the magnetic flux determined by the magnet specifications of the motor 100 and the periodic differential value of the angle between the magnet and the winding of the motor 100. The back electromotive force Ea can be calculated from the power supply voltage and the current flow time ratio (duty ratio) per one period of the motor 100. Here, the theoretical angular velocity is the rotation speed at the point where the voltage obtained by adding the applied voltage supplied to the motor 100 and the voltage drop due to losses inside the motor 100 balances with the back electromotive force. Therefore, the theoretical angular velocity of the motor 100 under no load can be obtained using the above formula.

[0042] On the other hand, the actual angular velocity (real angular velocity) of the motor 100 can be obtained by time-differentiating the value detected by the angle detection unit 250. Therefore, by calculating the theoretical angular velocity and the actual angular velocity and comparing them, deterioration of the motor 100 can be detected.

[0043] The deterioration detection of the motor 100 will be described with reference to Fig. 6. The upper part of Fig. 6 shows current waveforms 252 when the motor 100 is energized and when it is not energized. The current waveforms 252 when the motor 100 is energized and when it is not energized are controlled by changing the duty ratio of the H-bridge circuit 210 when it is on and off. More specifically, the current waveform 252 in Fig. 6 includes many on-off waveforms such as those shown in Fig. 5.

[0044] The middle part of FIG. 6 shows the motor angle monitor value 253 detected by the angle detection unit 250. The lower part of FIG. 6 shows the theoretical angular velocity 254 of the angular velocity W calculated based on the current waveform 252 and the actual angular velocity 255 obtained by time-differentiating the motor angle monitor value 253. Normally, the actual angular velocity 255 should match the theoretical angular velocity 254 (example of the left waveform in FIG. 6). However, when comparing the theoretical angular velocity 254 and the actual angular velocity 255, a difference of a predetermined value or more may occur. When such a difference occurs, it can be determined that some abnormality exists. Here, a situation in which the actual angular velocity 255 exceeds the theoretical angular velocity 254 (example of the central waveform in FIG. 6) is an example that does not normally occur due to deterioration of the motor 100. In this case, a failure of the current detection unit 240 or a failure of the angle detection unit 250 or the detector 251 is assumed. Conversely, when actual angular velocity 255 is lower than theoretical angular velocity 254 (example of the waveform on the right side of FIG. 6), it can be determined that deterioration of motor 100 due to aging or the like has occurred. In particular, the smaller actual angular velocity 255 is than theoretical angular velocity 254, the greater the degree of deterioration can be determined to be.

[0045] Therefore, if actual angular velocity 255 is, for example, 5 percent smaller than theoretical angular velocity 254, the deterioration rank is set to 1, and the deterioration level is increased for each 5 percent thereafter. If it is 20 percent smaller, the deterioration rank is 4, and if it is 30 percent or more smaller, the deterioration rank is 6, and in this example, deterioration rank 6 is determined to be a malfunction. Even if actual angular velocity 255 is greater than the theoretical angular velocity, if the deviation becomes large, some kind of malfunction is still suspected. If actual angular velocity 255 is greater than the theoretical angular velocity, as described above, a malfunction of current detection unit 240 or the like is suspected, rather than deterioration or malfunction of motor 100.

[0046] In the example of FIG. 6, at the first detection point 256 (the waveform on the left side of FIG. 6), the actual angular velocity 255 matches the theoretical angular velocity, and the motor 100 is operating normally. At the second detection point 257 (the waveform in the center of FIG. 6), the actual angular velocity 255 is greater than the theoretical angular velocity 254, so a failure other than that of the motor 100 is assumed. On the other hand, at the third detection point 258 (the waveform on the right side of FIG. 6), the actual angular velocity 255 is smaller than the theoretical angular velocity 254. Moreover, the deviation is 30 percent or more. In the above example, the deterioration rank is increased by one rank every time the theoretical angular velocity decreases by, for example, 5 percent. Therefore, at the third detection point 258, deterioration of rank 6 of the motor 100 is detected.

[0047] Next, the operation of the correction control unit 200B for correcting the motor 100 will be described with reference to the flowcharts of Fig. 7, Fig. 9, Fig. 10A and Fig. 10B and the table of Fig. 8. In the flowchart of Fig. 7, a correction request is judged. Starting at step S270, the vehicle's mileage since the previous correction is calculated at step S271. The signal from the odometer is stored in the memory of the control unit 200, and the vehicle's mileage is calculated from the difference between the mileage at the time of the previous correction and the mileage obtained this time.

[0048] In the next step S272, the current deterioration rank of the motor 100 is confirmed. The deterioration rank will be described later with reference to the flowcharts of FIG. 10A and FIG. 10B. Then, in step S273, the mileage at which correction is required at the current deterioration level is calculated. This mileage is calculated using the table shown in FIG. 8. For example, in the deterioration rank 1 where there is almost no deterioration, correction is not performed unless the mileage from the previous correction exceeds 3000 kilometers. The mileage until correction is required becomes shorter according to the deterioration level. For example, when the automobile has traveled 30000 kilometers, the deterioration level becomes deterioration rank 2, and the mileage becomes 32000 kilometers after traveling 2000 kilometers, and correction is performed. Also, for example, if the deterioration rank is 4 after traveling 100000 kilometers, the timing for the next correction will be 100500 kilometers after traveling 500 kilometers. As described above, the deterioration rank is divided into five stages from 1 to 5, and when the deterioration progresses further from deterioration rank 5 to deterioration rank 6, the motor 100 is determined to be broken and prohibited from use for safety reasons.

[0049] In step S274, the additional mileage calculated in step S271 is compared with the learning request distance calculated in step S273. If the learning request distance is greater than the additional mileage (No), the process proceeds to step S275, where the flow ends without performing any processing. If the additional mileage is greater than the learning request distance (Yes), the process proceeds to step S276, where the correction request flag is set, and the motor deterioration detection request flag is also set, whereupon the flow ends.

[0050] In the flowchart of Fig. 9, a judgment is made as to whether or not correction should be performed. Starting at step S280, it is confirmed at step S281 whether or not the correction request flag is on. The correction request flag is set at step S276 described above. If the correction request flag is not set (No), the process proceeds to step S282, where the flow ends without performing any processing. If the correction request flag is set (Yes), the process proceeds to step S283.

[0051] In step S283, it is determined whether all prerequisites required for correction are satisfied. The prerequisites include that the vehicle speed is zero, the accelerator opening is 0 percent (a state in which the depression amount of the accelerator pedal 111 is not detected), the shift lever position is in the parking (P) range or the neutral (N) range, the parking brake is on, and no fault detection is being performed on other circuits. If any one of these conditions is not met, the process proceeds to step S282, where the flow ends without performing any processing. If all prerequisites are satisfied, the process proceeds to the current correction step S284.

[0052] In the current correction step S284, in step S2841, switching unit 231 is switched so that the current flows through correction resistor 230 instead of motor 100. In step S2842, it is confirmed that the preconditions of step S283 described above are maintained. If not (No), the process proceeds to step S2843, where the correction is interrupted. In step S2843, switching unit 231 is switched in step S2844, where the current flows to the motor 100 side, and after the switching, the process proceeds to step S282, where the flow ends without performing any processing.

[0053] If it is confirmed in step S2842 that the detection conditions are maintained (Yes), in step S2845, the current detection unit 240 reads the correction resistor monitor current value 241 based on the actual current value of the correction resistor 230. The correction resistor monitor current value 241 is read multiple times (for example, three times) in step S2845, and steps S2845 to S2842 are looped. The correction control unit 200B averages the correction resistor monitor current value 241 detected multiple times to calculate the correction resistor monitor current value 241. The clock of the microcomputer in the control unit 200 is assumed to be 16 MHz, and the AD converter (analog digital signal input / output function) in the control unit 200 is also assumed to have a drive cycle of about 1 MHz. The time required for the actual reading is less than 1 microsecond even if the correction resistor monitor current value 241 is detected multiple times. Therefore, multiple readings are possible in terms of time.

[0054] Once reading of the correction resistor monitor current value 241 is complete, the process proceeds to step S2846, where the control unit 200 calculates a correction term for the motor control device 260 itself. This correction term is the offset amount 243 described in FIG. 4 and the difference between the correction resistor theoretical on / off current value 244 and the correction resistor monitor on / off current value 245. Once calculation of the correction term is complete, the switching unit 231 is switched to pass a current to the motor 100 side. This is the current correction step S284, whereby the self-diagnosis of the motor control device 260 is completed.

[0055] When the current correction step S284 of the motor control device 260 is completed in step S2846, the process proceeds to step S285, where learning control of the motor 100 is started. In step S285, the correction request flag set in step S276 is cleared. Furthermore, the value of the correction term calculated in step S2845 is stored in the memory of the control unit 200 (correction control unit 200B) as a history value. Furthermore, the traveling distance of the automobile when the correction was executed is stored in the memory of the control unit 200 (correction control unit 200B).

[0056] Next, the flow proceeds to step S286, where it is determined whether there is a problem with at least one of the offset amount 24F, which is a correction term, and the difference between the motor theoretical on / off current value 24D and the motor monitor on / off current value 24C. If there is no problem (No), the flow proceeds to step S282 and ends. If a problem is detected (Yes), the flow performs the correction process described in FIG. 5 in step S287. That is, the offset amount 24F is reduced, and the difference between the motor theoretical on / off current value 24D and the motor monitor on / off current value 24C is reduced. This corrects changes due to aging of the motor 100, and learning control corresponding to the changes in the motor 100 is executed. After the above corrections are executed, the flow ends.

[0057] The above-mentioned detection of deterioration of the motor 100 will be described with reference to the flowcharts of FIG. 10A and FIG. 10B. In step S290, execution of deterioration detection of the motor 100 is started. In the next step S291, it is detected whether or not the deterioration detection flag is set. The deterioration detection flag is set in step S276 of the correction request determination. If the deterioration detection request flag is not set (No), the process proceeds to step S292, where the flow ends without any processing. If the deterioration detection request flag is set (Yes), the process proceeds to step S293, where it is determined whether the learning control (current correction) of the motor 100 described in the flowchart of FIG. 9 has been completed. In other words, the completion of the current correction is a determination of whether or not the correction execution determination step S287 has been completed. If it has not been completed (No), the process proceeds to step S292, where the flow ends without any processing.

[0058] If step S287 for executing correction has been completed (Yes), the flow proceeds to step S294 to confirm that all detection conditions are met. This step S294 is the same as step S283 for determining whether correction is to be performed. That is, the prerequisites required for performing correction include the vehicle speed being zero, the accelerator opening being 0 percent, the position of the shift lever being in the parking (P) range or neutral (N) range, the handbrake being on, and failure detection of other circuits not being performed. If any one of these conditions is not met (No), the flow proceeds to step S292 to end the flow. If all prerequisites are met (Yes), the flow proceeds to the next step S295 for executing motor deterioration detection.

[0059] In the motor deterioration detection execution step S295, in step S2951, it is confirmed that the preconditions in step S294 are maintained. This is the same as step S2842 in the correction execution determination process. If they are not maintained (No), the process proceeds to step S2952, where the deterioration detection is interrupted. Next, in step S2953, the motor 100 is returned to the initial position, and the process proceeds to step S292, where the flow ends. Note that the initial position of the motor 100 is a position where the transmission mechanism 112 is not in contact with the accelerator pedal 111 in the case of the haptic device 110 in FIG. 1.

[0060] If it is confirmed in step S2951 that the detection conditions are maintained (Yes), the process proceeds to step S2954, where the motor monitor current value 24A is read by the current detection unit 240. In this step S2954, the motor angle monitor value 253 of the motor is also read by the angle detection unit 250. Also in step S2954, a predetermined duty is instructed to the control unit 200 (correction control unit 200B) to repeat reading of the current detection unit 240 and the angle detection unit 250 multiple times. In step S2954, reading is continued for a certain period of time (several milliseconds) in order to improve the accuracy of reading the motor monitor current value 24A and the actual angular velocity 255. The certain period of time is assumed to be the time it takes for the rotation of the motor 100 to be transmitted to the accelerator pedal 111 via the transmission mechanism 112.

[0061] While it is being confirmed in step S2951 that the detection conditions are maintained, if the reading of signals from the current detection unit 240 and the angle detection unit 250 in step S2954 is completed, then in step S2955, a theoretical angular velocity 254 under no load is calculated based on the motor monitor current value 24A from the current detection unit 240. Also, an actual angular velocity 255 is calculated by time-differentiating the motor angle monitor value 253 detected by the angle detection unit 250. Next, in step S2956, the actual angular velocity 255 and the theoretical angular velocity 254 are compared, and the deterioration is ranked according to the degree of deviation. In the example of FIG. 8, the deterioration levels are classified into five stages, from rank 1, which indicates mild deterioration, to rank 5, which indicates advanced deterioration.

[0062] As described above, reading from the current detection unit 240 and reading from the angle detection unit 250 are performed multiple times. This may involve comparing the theoretical angular velocity 254 with the actual angular velocity 255 for each reading, or multiple readings may be performed and then the theoretical angular velocity 254 and actual angular velocity 255 may be compared all at once. However, in order to reduce variation, it is preferable to calculate the results of multiple readings together, as this averages the values. In either case, there is a sufficient margin for calculation in the control unit 200 (correction control unit 200B).

[0063] As described above, when the deterioration rank reaches 6, it is determined that the motor 100 has a failure. However, the failure of the motor 100 can be determined not only by the deterioration rank but also by other means. Below, another example of failure detection will be described in steps S2957 and S2958 of FIG. 10B. In step S2957, it is determined whether the maximum angular velocity of the real angular velocity 255 is equal to or lower than a predetermined value, and whether the maximum angular acceleration of the real angular velocity 255 is equal to or lower than a predetermined value. Note that the maximum acceleration means the maximum value of the angular acceleration obtained by differentiating the real angular velocity 255 with respect to time or angle. If the maximum angular velocity and maximum acceleration are not equal to or lower than the predetermined value (No), it is determined that the motor 100 has no failure, and the process proceeds to step S296 to return the motor to its initial position.

[0064] If the maximum angular velocity or maximum angular acceleration is equal to or less than a predetermined value (Yes), in step S2958, it is confirmed whether the cumulative angular displacement during energization is equal to or less than a predetermined value. If it is not equal to or less than the predetermined value (No), it is determined that the motor 100 is angularly displaced and is not broken. In this case, the process proceeds to step S296, where the motor is returned to its initial position. If the cumulative angular displacement is equal to or less than a predetermined value (Yes), it is suspected that the motor 100 is not angularly displaced. In the example of FIG. 1, it is assumed that the accelerator pedal 111 is in a dead-end state. In this case, in step S2959, motor failure detection is performed, and the occupant is notified of the failure of the motor 100 by a warning light, a warning sound, or the like. Although not described in the flowchart of FIG. 10B, even if the deterioration rank is determined to be 6 in step S2956, the process proceeds to step S2959. Then, the occupant is notified of the failure of the motor 100 by a warning light, a warning sound, or the like. In addition to notifying the failure, the operation of the motor 100 may be stopped, or no correction of the motor 100 may be performed, until the failure is repaired and the failure flag is cleared.

[0065] After motor failure detection in step S2959 or motor deterioration detection in step S2956, the motor 100 is returned to the initial position in step S296. Next, the motor deterioration detection request flag is cleared in step S297, and the flow ends.

[0066] As described above, according to the present disclosure, first, the motor control device 260 is corrected by the correction control unit 200B, and the motor control device 260 is self-diagnosed, and then the motor 100 is corrected. This makes it possible to reliably correct changes due to aging of the motor control device 260 and the motor 100. If a change occurs in the motor control device 260 or the motor 100, the output of the motor 100 will not be a specified value as a result. In other words, when used in the haptic device 110, the specified function and performance will not be achieved. In contrast, by using the present disclosure, it is possible to always operate the motor 100 with the specified performance.

[0067] In the flowchart of FIG. 10B, both the maximum angular velocity (step S2957) and the accumulated angular displacement (step S2958) are used in step S2959 for motor failure detection, but failure may be detected using only one of them. Also, in the flowchart of FIG. 10B, in addition to detecting a failure of motor 100 due to a worsening deterioration rank, a failure of motor 100 is detected using the maximum angular velocity, maximum angular acceleration, and accumulated angular displacement. This is desirable as it allows for more accurate detection of failures of motor 100. However, it is also possible to use only one of failure detection based on the deterioration rank of motor 100 and failure detection using the maximum angular velocity, maximum angular acceleration, and accumulated angular displacement. In that case, the control flow for detecting a failure of motor 100 due to deterioration rank is lighter.

[0068] Furthermore, when particularly severe deterioration is detected in motor deterioration detection step S2956, even if the deterioration is of special deterioration rank 6 or higher, motor failure detection step S2959 may be performed to determine that motor 100 has failed. Also, it is possible to simply omit motor failure detection step S2959 so that abnormalities in motor 100 are not detected.

[0069] In addition, in the example of FIG. 8, the deterioration rank is divided into five stages, but this is just one example, and the rank division may be made more detailed, or the number of rank divisions may be reduced. Furthermore, the rank division may be abolished. The length of the learning required distance is also one example. The execution required distance is practical to change according to the deterioration rank, but other factors can also be used. It is also possible to use the time since the start of use or the cumulative power supply time instead of or together with the execution required distance.

[0070] Also, in the above example, the correction request flag and the motor deterioration detection request flag are set simultaneously in step S276 of the correction request determination, but only the correction request flag may be set in step S276. In this case, the motor deterioration detection flag can be set at a different timing. For example, the correction request flag and the motor deterioration detection request flag can be set to have different execution request distances. More specifically, even if a execution request distance of 3000 kilometers is required to set the correction request flag, the motor deterioration detection request flag can be set with a execution request distance of 500 kilometers.

[0071] In the above description, the correction control unit 200B of the control unit 200 first corrects the motor control device 260, self-diagnoses the motor control device 260, and then corrects the motor 100. However, among the functions of the correction control unit 200B, it is also possible to only correct the motor control device 260 including the H-bridge circuit 210. This is a correction when changes such as aging deterioration occur in the H-bridge circuit 210 or the like, or when the H-bridge circuit 210 or the like is replaced.

[0072] As described above, performing self-diagnosis of the motor control device 260 is desirable in order to accurately correct the motor 100. However, it is theoretically possible to specialize the correction of the motor 100, in particular the correction of the motor 100 according to the deterioration rank. Therefore, it is conceivable that the correction of the motor control device 260 including the H-bridge circuit 210 and the like may not be used as necessary.

[0073] In the above example, a single control unit 200 functions as the motor control unit 200A and the correction control unit 200B, but the motor control unit 200A and the correction control unit 200B may be configured separately. In that case, the correction control unit 200B can more directly correct for changes such as aging deterioration of the motor control unit 200A or changes when the motor control unit 200A is replaced.

[0074] Furthermore, the above is a preferred example of the present disclosure, but the present disclosure can be modified in various ways. The haptic device 110 is not limited to the accelerator pedal 111 for conveying information to the occupant. For example, the steering wheel or the seat may be vibrated. Furthermore, the haptic device 110 is also an example, and can be widely used for correcting motors mounted on automobiles. Examples include a wiper motor and a motor for controlling the throttle valve opening. [Explanation of symbols]

[0075] 100 Motor 110 Haptic Device 200 Control section 210 H-Bridge Circuit 230 Compensation Resistor 231 Switching section 240 Current detection section 250 Angle detection unit

Claims

1. A motor that rotates when supplied with electric current; A motor control unit configured separately from the motor and controlling the rotation of the motor; a current detection unit that detects a current supplied from the motor control unit; an angle detection unit that detects rotation of the motor; A compensation resistor arranged in parallel with the motor in an electrical circuit; a switching unit that switches the supply of current between the motor side and the correction resistor side; a correction control unit that corrects a change in a current value of at least one of the motor and the motor control unit, The correction control unit performs correction resistance zero point correction, which is a correction of the correction resistance zero point of the current value, and correction resistance gain correction, which is a correction of the correction resistance gain value, which is the difference between the current value when current is applied and when current is not applied, based on the detected current from the current detection unit when current is applied to the correction resistance and the detected current from the current detection unit when current is not applied to the correction resistance, so as to bring the monitored current value, which is an actual measured value, closer to the theoretical current value, which is a calculated value. A motor control device comprising:

2. The correction control unit inputs a motor monitor zero point during non-energization based on a motor current value in a state where the switching unit switches the current to the motor side, and the correction resistor zero point in a state where the switching unit switches the current to the correction resistor side, and corrects the offset amount, which is the difference between the motor monitor zero point and the motor theoretical zero point calculated based on the correction resistor zero point, in a direction to reduce the offset amount.

2. The motor control device according to claim 1 .

3. The correction control unit inputs a motor monitor on / off current value, which is a difference between an actual current value when current is applied and an actual current value when current is not applied based on a motor current value in a state in which the current is switched to the motor side by the switching unit, and a motor theoretical on / off current value calculated based on the correction resistance gain value, and makes a correction in a direction to reduce the difference between the motor monitor on / off current value and the motor theoretical on / off current value.

3. The motor control device according to claim 1 or 2.

4. The correction control unit calculates deterioration based on the signal from the angle detection unit, and corrects the change when a deterioration equal to or greater than a predetermined level is calculated.

2. The motor control device according to claim 1 .

5. The correction control unit uses a theoretical angular velocity of the motor under no load, which is calculated using an electromotive force constant determined by the specifications of the motor and a back electromotive force when the motor is energized, and an actual angular velocity of the motor detected by the angle detection unit, and determines deterioration when a difference between the theoretical angular velocity and the actual angular velocity becomes a predetermined value or more, and corrects the change.

5. The motor control device according to claim 4.

6. The correction control unit distinguishes between a plurality of deterioration ranks and changes the frequency of correction of the change according to the deterioration rank.

6. The motor control device according to claim 4 or 5.

7. The correction control unit detects a failure of the motor based on a signal from the angle detection unit, and when a failure is detected, determines that the motor is abnormal.

2. The motor control device according to claim 1 .

8. The correction control unit detects a failure when a maximum angular velocity and a maximum angular acceleration while the motor is energized are equal to or smaller than a predetermined value, and when a cumulative angular displacement while the motor is energized is equal to or smaller than a predetermined value.

8. The motor control device according to claim 7.

9. the motor is an automotive motor, The correction control unit corrects the change when the vehicle is stopped.

2. The motor control device according to claim 1 .

10. The correction control unit corrects the change when the following conditions are satisfied: The car's speed is zero The accelerator pedal is at zero The shift position is either in the parking range or the neutral range. The parking brake is on The angle detection unit does not detect the rotation of the motor. The motor control device according to claim 9 .

11. The motor vibrates the accelerator pedal to communicate information to the occupant. The motor control device according to claim 9 .

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