Motor control device

Abstract

A motor control device (40) controls driving of a motor (10) having a motor winding (11), and includes a driving control section (51) and a parameter setting section (55). The driving control section (51) controls driving of the motor (10). The parameter setting section (55) sets a control parameter of the driving control of the motor (10) in such a manner that at least one of a motor torque and a motor speed can be changed in accordance with a system temperature.

Description

[0001] Cross-references to related applications

[0002] This application is based on Japanese Patent Application No. 2020-066013, filed on April 1, 2020, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to motor control devices. Background Technology

[0004] Previously, gear shifting devices were known to switch gears by controlling the drive of a motor. For example, in Patent Document 1, a method was described where the number of energized phases was kept constant during collision control, and the motor was driven to rotate by sequentially switching the energized phases of the motor using either a single-phase or two-phase energizing method.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-100041 Summary of the Invention

[0008] When driving a motor with single-phase or two-phase power, the torque decreases more easily near the angle of phase switching compared to repeated single-phase and two-phase power switching. If the motor stops due to load torque at the angle where torque decreases, insufficient torque may prevent restarting. The object of this disclosure is to provide a motor control device capable of appropriately and continuously driving a motor.

[0009] The motor control device disclosed herein controls the drive of a motor having motor windings, and includes a drive control unit and a parameter setting unit. The drive control unit controls the drive of the motor. The parameter setting unit sets control parameters for the motor drive control based on the system temperature in a manner that allows at least one of the motor torque and motor speed to change. This prevents motor stoppage caused by insufficient torque, thereby ensuring proper and continuous motor drive. Attached Figure Description

[0010] The above-mentioned objects, other objects, features, and advantages of this disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawings are as follows:

[0011] Figure 1 This is a perspective view showing the shift-by-wire system of the first embodiment;

[0012] Figure 2 This is a schematic structural diagram of the shift-by-wire system according to the first embodiment;

[0013] Figure 3 This is a circuit diagram showing the gear shift control device of the first embodiment;

[0014] Figure 4 This is a block diagram showing the ECU of the first embodiment;

[0015] Figure 5A This is a diagram showing the energizing mode and energizing phase of the first embodiment;

[0016] Figure 5B This is a graph showing the relationship between the electrical angle and the motor torque in the first embodiment;

[0017] Figure 6 This is a flowchart illustrating the motor drive process of the first embodiment;

[0018] Figure 7 This is a flowchart illustrating the low-temperature determination process of the first embodiment;

[0019] Figure 8 This is a flowchart illustrating the parameter setting process of the first embodiment;

[0020] Figure 9 This is a timing diagram illustrating the motor drive process of the first embodiment;

[0021] Figure 10 This is a flowchart illustrating the parameter setting process of the second embodiment;

[0022] Figure 11 This is a timing diagram illustrating the motor drive process of the second embodiment;

[0023] Figure 12 This is a flowchart explaining the parameter setting process of the third embodiment;

[0024] Figure 13 This is a timing diagram illustrating the motor drive process of the third embodiment;

[0025] Figure 14 This is a timing diagram illustrating the motor drive process of the reference example. Detailed Implementation

[0026] The motor control device will now be described with reference to the accompanying drawings. In several embodiments, substantially the same structures will be labeled with the same reference numerals, and descriptions will be omitted.

[0027] <First Implementation Method>

[0028] Figures 1-9 This indicates the first implementation method. For example... Figure 1and Figure 2 As shown, the drive-by-wire shift system 1 includes a motor 10, a shift gear switching mechanism 20, a parking lock mechanism 30, and a shift gear control device 40 as a motor control device.

[0029] The motor 10 is rotated by being powered by a battery 90 installed in a vehicle (not shown), and functions as a drive source for the gear shifting mechanism 20. The motor 10 is, for example, a switched reluctance motor. The motor 10 has a motor winding 11 with salient poles wound around a stator (not shown). The motor winding 11 has a U-phase winding 111, a V-phase winding 112, and a W-phase winding 113 (see reference). Figure 3 By controlling the energization of the motor winding 11, the rotor (not shown) is rotated.

[0030] like Figure 2 As shown, the encoder 13, acting as a rotary position sensor, detects the rotational position of the rotor (not shown) of the motor 10. The encoder 13 is, for example, a magnetic rotary encoder, consisting of a magnet that rotates integrally with the rotor and a Hall effect IC for magnetic detection. The encoder 13 outputs A-phase and B-phase pulse signals, i.e., encoder signals, at predetermined angles in sync with the rotor's rotation. The reducer 14 is disposed between the motor shaft and the output shaft 15 of the motor 10, reducing the rotation of the motor 10 and outputting it to the output shaft 15. Thus, the rotation of the motor 10 is transmitted to the gear shifting mechanism 20. In this embodiment, the output shaft sensor for detecting the angle of the output shaft 15 is omitted.

[0031] like Figure 1 As shown, the gear shifting mechanism 20 has a stop plate 21 and a stop spring 25, etc., which transmit the rotational driving force output from the reducer 14 to the manual valve 28 and the parking locking mechanism 30.

[0032] A stop plate 21 is fixed to the output shaft 15 and driven by the motor 10. A pin 24 protrudes from the stop plate 21, parallel to the output shaft 15. The pin 24 is connected to a manual valve 28. The manual valve 28 reciprocates axially by driving the stop plate 21 with the motor 10. That is, the gear shifting mechanism 20 converts the rotational motion of the motor 10 into linear motion and transmits it to the manual valve 28. The manual valve 28 is located on the valve body 29. By causing the manual valve 28 to reciprocate axially, the hydraulic supply path to a hydraulic clutch (not shown) is switched, changing the engagement state of the hydraulic clutch, thereby changing the gear position.

[0033] Two valleys 211 and 212 are provided on the stop spring 25 side of the stop plate 21. In this embodiment, valley 211 corresponds to the P gear, and valley 212 corresponds to gears other than P gear, i.e., non-P gear.

[0034] The stop spring 25 is a plate-shaped component capable of elastic deformation, with a stop roller 26 at its front end. The stop spring 25 applies force to the stop roller 26 towards the rotation center of the stop plate 21. If a rotational force above a specified level is applied to the stop plate 21, the stop spring 25 undergoes elastic deformation, and the stop roller 26 moves between the valleys 211 and 212. By engaging the stop roller 26 in either valley 211 or 212, the swing of the stop plate 21 is restricted, the axial position of the manual valve 28 and the state of the parking lock mechanism 30 are determined, and the shift gear of the automatic transmission 5 is fixed.

[0035] The parking locking mechanism 30 includes a parking lever 31, a cone 32, a parking locking pawl 33, a shaft 34, and a parking gear 35. The parking lever 31 is generally L-shaped, with one end 311 fixed to the stop plate 21. The cone 32 is provided at the other end 312 of the parking lever 31. The cone 32 is formed such that its diameter decreases as it approaches the other end 312. If the stop plate 21 rotates toward the stop roller 26 to engage with the valley 211 corresponding to the P position, the cone 32 moves in the direction of arrow P.

[0036] The parking lock pawl 33 is configured to abut against the conical surface of the cone 32 and is capable of swinging about the shaft 34. On the parking gear 35 side of the parking lock pawl 33, a protrusion 331 is provided that can engage with the parking gear 35. If the cone 32 moves in the direction of arrow P due to the rotation of the stop plate 21, the parking lock pawl 33 is pushed upwards, and the protrusion 331 engages with the parking gear 35. Conversely, if the cone 32 moves in a direction other than arrow P, the engagement between the protrusion 331 and the parking gear 35 is disengaged.

[0037] The parking gear 35 is located on an axle (not shown) and is configured to engage with the protrusion 331 of the parking lock pawl 33. When the parking gear 35 engages with the protrusion 331, rotation of the axle is restricted. When the shift position is not P (Park), the parking gear 35 is not locked by the parking lock pawl 33, and rotation of the axle is not hindered by the parking lock mechanism 30. Conversely, when the shift position is P (Park), the parking gear 35 is locked by the parking lock pawl 33, and rotation of the axle is restricted.

[0038] like Figure 2 and Figure 3 As shown, the gear shift control device 40 includes a drive circuit unit 41, a current detection unit 45, and a drive-by-wire shift ECU 50, etc. Figure 3As shown, the drive circuit section 41 has three switching elements 411, 412, and 413. In this embodiment, the drive circuit section 41 is disposed between the windings 111-113 of each phase and the ground wire. The switching elements 411-413 are disposed corresponding to the windings 111-113 of each phase, and switch the energization of the corresponding phase. In this embodiment, the switching elements 411-413 are MOSFETs, but they can also be IGBTs or the like.

[0039] The windings 111 to 113 of the motor winding 11 are connected together by a terminal block 115. Power is supplied to the terminal block 115 from the battery 90 via a power line 901. A relay 91 is provided on the power line 901, and when the relay 91 is turned on, power is supplied to the terminal block 115. A current detection unit 45 is provided on the junction box 451 that connects the source and ground of the switching elements 411 to 413, and detects the sum of the currents flowing in the windings 111 to 113, i.e., the junction box current Ia.

[0040] The shift-by-wire ECU 50 internally includes a CPU, ROM, RAM, I / O devices, and buses connecting these structures (not shown). The processing within the ECU 50 can be software processing, implemented by the CPU executing programs pre-stored in a physical storage device such as ROM (i.e., a readable non-transitory tangible recording medium), or hardware processing based on dedicated electronic circuitry. The same applies to the transmission ECU 61, engine ECU 62, and air conditioning ECU 63.

[0041] like Figure 4 As shown, the shift-by-wire ECU 50 is configured to communicate with the transmission ECU 61, engine ECU 62, and air conditioning ECU 63 via a vehicle communication network 65 such as CAN (Controller Area Network). Hereinafter, ECU 50 will be appropriately written as "SBW-ECU50" or simply as "ECU50", and the transmission ECU 61 will be written as "TM-ECU61".

[0042] like Figure 2 As shown, SBW-ECU50 controls gear shifting by controlling the drive of motor 10 based on a shift signal corresponding to the driver's requested gear, a signal from the brake switch, and vehicle speed. TM-ECU61 controls the drive of the transmission hydraulic control solenoid 6 based on vehicle speed, accelerator opening, and the driver's requested gear. The transmission stages are controlled by controlling the transmission hydraulic control solenoid 6. The transmission hydraulic control solenoid 6 has a number of lines corresponding to the number of transmission stages. In this embodiment, SBW-ECU50 and TM-ECU61 are configured as separate ECUs, but they can also be configured as a single ECU. The following explanation focuses on the drive control of motor 10.

[0043] The SBW-ECU50 includes a drive control unit 51 and a parameter setting unit 55. The drive control unit 51 controls the energization of the motor winding 11 based on the encoder count value Cen corresponding to the encoder signal from the encoder 13, indicating the energized phase. Whenever an edge of the encoder signal is detected, the encoder count value Cen is incremented or decremented. In this embodiment, the encoder count value Cen is incremented during forward rotation and decremented during reverse rotation. Furthermore, current limiting is applied to ensure that the current Ia in the collector does not exceed the current limit value.

[0044] The parameter setting unit 55 obtains the transmission oil temperature thto from TM-ECU 61, the engine oil temperature theo and the engine coolant temperature thew from engine ECU 62, and the ambient air temperature thg from air conditioning ECU 63, and performs low-temperature judgment processing (see reference). Figure 4 Additionally, the parameter setting unit 55 sets the drive control parameters of the motor 10 based on the determination result. Details regarding the low-temperature determination process and parameter setting process will be described later.

[0045] like Figure 5A As shown, the relationship between the power-on mode number and the power-on phase is stored in a storage unit (not shown). Whenever a pulse edge of the encoder signal is detected, the drive control unit 51 changes the power-on mode by +1 for forward rotation and -1 for reverse rotation. By switching the power-on phase according to the power-on mode, the motor 10 is rotated. Figure 5A In the diagram, for a cycle in which energizing modes P0 to P11 correspond to one period of electrical angle, circles are used to represent the phases energized in each energizing mode. Furthermore, to avoid complexity, the symbol "P" representing the mode number is omitted from the diagram; only the number is shown.

[0046] In this embodiment, instead of using single-phase energization to energize one phase of windings 111 to 113, the motor 10 is rotated by repeatedly energizing two phases of windings 111 to 113. Figure 5B The horizontal axis is set to electrical angle, and the vertical axis to motor torque, representing the motor torque corresponding to one electrical angle cycle. Furthermore, the motor torque is recorded assuming constant current in each phase. Additionally, a single-dotted line represents the torque generated when one phase is energized, a double-dotted line represents the torque generated when two phases are energized, and a triangle symbol represents the encoder edge generation location. The energizing mode is also recorded. Furthermore, in the symbols representing the encoder edge generation location, the areas where the energizing phases switch are shaded.

[0047] In this embodiment, under power-on modes P0-P2 and P11, the WU phase is energized by turning on switching elements 411 and 413. If an encoder edge is detected in power-on mode P2, switching elements 411 and 412 are turned on, switching to UV phase energization. Under power-on modes P3-P6, UV phase energization continues. If an encoder edge is detected in power-on mode P6, switching elements 412 and 413 are turned on, switching to VW phase energization. Under power-on modes P7-P10, VW phase energization continues. If an encoder edge is detected in power-on mode P10, switching to WU phase energization.

[0048] like Figure 5B As shown by the solid line, the motor torque tends to decrease near the angle of the switching phase. This decrease is especially pronounced at low temperatures, where the increased sliding resistance both inside and outside the actuator further reduces the motor torque. If the motor 10 stops at the angle where the torque decreases, it may be unable to restart due to insufficient torque.

[0049] When the rotational speed of motor 10 is high, there is a high probability that it can pass through the torque reduction region by inertia. On the other hand, when the rotational speed of motor 10 is low, motor 10 is prone to stop due to torque reduction. In this embodiment, the wall portion of the stop roller 26 on the side opposite to valley 212 (hereinafter referred to as "P wall") is set as the drive limit position of the motor, and the P wall position is learned as a reference position. Alternatively, the wall portion of valley 212 on the side opposite to valley 211, i.e., the non-P wall, can also be set as the "drive limit position", and the non-P wall position is learned as a reference position. Here, when learning the reference position, the rotational speed of motor 10 is suppressed in consideration of durability.

[0050] In the absence of an output shaft sensor as in this embodiment, when the SBW-ECU50 is started, it is impossible to determine which of the valleys 211 and 212 the stop roller 26 is in. Therefore, when learning the reference position by abutting against the P wall, if the stop roller 26 is in valley 212, it is necessary to cross the peak 215 between valleys 211 and 212, and the motor 10 may stop due to the stop load.

[0051] That is, during reference position learning under two-phase energization, when it is necessary to cross the peak 215 between valleys 211 and 212, if the increase in friction caused by low temperature overlaps during low-speed drive, the motor 10 may stop while climbing the peak 215. Furthermore, the motor 10 may not be able to restart due to insufficient torque. In this specification, "low speed" is defined as a speed of (e.g., 500 rpm or less) at which the friction increases at low temperatures (e.g., below 0°C, preferably below -20°C), causing a decrease in torque near the phase switching point during two-phase energization, resulting in the inability to cross the peak 215.

[0052] Therefore, in this embodiment, the motor 10 is kept running by changing the control parameters so that the driving torque of the motor 10 increases or the braking torque decreases at low temperatures.

[0053] based on Figure 6 The flowchart below describes the motor drive process of this embodiment. This process is performed during reference position learning when the vehicle's start switch is turned on. Hereinafter, the "step" of step S101 will be omitted and simply referred to as "S". The other steps are the same.

[0054] In S101, ECU50 determines whether a motor drive request exists. If no motor drive request is determined (S101: No), the processing after S102 is skipped. If a motor drive request is determined (S101: Yes), the process proceeds to S102. In S102, ECU50 performs a low-temperature determination process.

[0055] based on Figure 7 The flowchart below explains the low-temperature determination process. In S201, the parameter setting unit 55 obtains the temperature of each component from ECUs 61 to 63. In S202, the parameter setting unit 55 determines whether the transmission fluid temperature thto obtained from TM-ECU 61 is normal. If the transmission fluid temperature thto is determined to be normal (S202: Yes), the process proceeds to S203, and the system temperature thsys is set to the transmission fluid temperature thto. If the transmission fluid temperature thto is determined to be abnormal (S202: No), the process proceeds to S204. Here, "transmission fluid temperature thto abnormal" includes not only cases where the obtained value is abnormal, but also cases where temperature information cannot be obtained. The same applies to other temperatures.

[0056] In S204, the parameter setting unit 55 determines whether the engine coolant temperature thew obtained from the engine ECU 62 is normal. If the engine coolant temperature thew is normal (S204: Yes), the process proceeds to S205 and sets the system temperature thsys to the engine coolant temperature thtw. If the engine coolant temperature thew is abnormal (S204: No), the process proceeds to S206.

[0057] In S206, the parameter setting unit 55 determines whether the engine oil temperature theo obtained from the engine ECU 62 is normal. If the engine oil temperature theo is normal (S206: Yes), proceed to S207 and set the system temperature thsys to the engine oil temperature theo. If the engine oil temperature theo is abnormal (S206: No), proceed to S208.

[0058] In S208, the parameter setting unit 55 determines whether the outside gas temperature thg obtained from the air conditioning ECU 63 is normal. If the outside gas temperature thg is determined to be normal (S208: Yes), the process proceeds to S209, where the system temperature thsys is set to the outside gas temperature thg. If the outside gas temperature thg is determined to be abnormal (S208: No), the process proceeds to S210, where the system temperature thsys is set to the fault temperature tfail. The fault temperature tfail is an arbitrary design value; it can be set to the worst-case condition or the standard temperature. In the processing of S202 to S210, the temperature at the location as close as possible to the shift-by-wire system 1 is selected as the system temperature thsys.

[0059] In S211, the parameter setting unit 55 determines whether the system temperature thsys is above the low-temperature threshold thl. If the system temperature thsys is above the low-temperature threshold thl (S211: Yes), the process in S212 is skipped, and the low-temperature flag flg is not enabled. Additionally, if the low-temperature flag flg is enabled, it is disabled. If the system temperature thsys is lower than the low-temperature threshold thl (S211: No), S212 is entered, and the low-temperature flag flg is enabled. Hereafter, the state of enabling the low-temperature flag flg is set to "low temperature," and the state of disabling the low-temperature flag is set to "normal temperature."

[0060] Back Figure 6 In S103, following the low-temperature determination process (S102), the ECU50 performs parameter setting processing. Based on Figure 8 The flowchart explains the parameter setting process. The drive control unit 51 determines whether the motor speed SP of the motor 10 is greater than the target speed SP. * Small. The motor speed SP is determined to be the target speed SP. *In the above case (S301: No), proceed to S305. If it is determined that the motor speed SP is higher than the target speed SP... * In the case of a small error (S301: Yes), proceed to S302. Here, it can be said that S302 is the step entered when an acceleration request is made, and S305 is the step entered when a deceleration request is made.

[0061] In S302, which is entered upon requesting acceleration, the parameter setting unit 55 determines whether the low-temperature flag flg is disabled. If it is determined that the low-temperature flag flg is disabled (S302: Yes), i.e., at room temperature, the system enters S303 and sets the target current I. * Set the acceleration target value I1 at room temperature (e.g., 6.5 [A]). If the low temperature flag flg is determined to be enabled (S302: No), proceed to S304 and set the target current I... * Let the target acceleration value at low temperature be I2 (e.g., 7.5 [A]). The target acceleration value I2 at low temperature is greater than the target acceleration value I1 at normal temperature. That is, I1 < I2.

[0062] In step S305, which is entered upon deceleration request, parameter setting unit 55 determines whether the low-temperature flag flg is disabled. If it is determined that the low-temperature flag is disabled (S305: Yes), step S306 is entered, and the target current I is set. * Set the deceleration target value I3 at room temperature (e.g., 6.5 [A]). If the low temperature flag flg is determined to be enabled (S305: No), proceed to S307 and set the target current I... * Let the deceleration target value at low temperature be I4 (e.g., 5.5 [A]). The deceleration target value I4 at low temperature is smaller than the deceleration target value I3 at normal temperature. That is, I3 > I4. In addition, the acceleration target value I1 at normal temperature and the deceleration target value I3 at normal temperature can be equal or different.

[0063] Back Figure 6 In S104, which follows the parameter setting process (S103), the drive control unit 51 controls the drive of the motor 10 by two-phase energizing along the direction that moves the stop roller 26 toward the wall on the side of the valley 211. At this time, control is performed to make the current in the collection section Ia the target current I. * .

[0064] In S105, the drive control unit 51 determines whether the drive of the motor 10 is complete. During reference position learning, if the encoder count value Cen remains unchanged for more than the wall contact determination time Xth, the stop roller 26 is considered to be in contact with the P wall, and the drive of the motor 10 is determined to be complete. The encoder count value Cen at this time is also learned as the reference position. By cutting off the power supply to the motor 10, the stop roller 26 returns to the bottom of the valley 211 by the spring force of the stop spring 25. Alternatively, a return power supply process can be performed to return the stop roller 26 to the bottom of the valley 211. If it is determined that the drive of the motor 10 is not complete (S105: No), the process returns to S103. If it is determined that the drive of the motor 10 is complete (S105: Yes), the motor drive process ends.

[0065] based on Figure 9 The timing diagram illustrates the motor drive processing of this embodiment, based on... Figure 14 The timing diagram illustrates the motor drive process of the reference example. Here, it is assumed that the collision with the wall on the valley 211 side occurs from the state where the stop roller 26 is in valley 212, and the actuator temperature tact is lower than the low-temperature judgment value thl. Figure 9 and Figure 14 In the diagram, starting from the top layer, the control mode, encoder count value, motor 10 rotational speed, phase shift, motor torque, and target current are shown. The timing diagrams for the embodiments described later are also the same. Additionally, in... Figure 9 In the diagram, the target current I at low temperature is represented by a solid line. * The target current I at room temperature is represented by a dashed line. * .

[0066] like Figure 14 As shown, at time x90, the control mode is switched from standby mode to feedback mode, and wall-blocking control begins. In feedback control, the drive of motor 10 is controlled via a two-phase drive based on the encoder count value Cen. The motor speed SP is greater than the target speed SP. * When acceleration is requested between times x90 and x91, x92 and x93, and x95 and x96, the motor speed SP is the target speed SP. * The times x91 to x92 and x93 to x95 above are the times when deceleration is requested.

[0067] If, as in the reference example, the target current I is at low temperature *If the speed is set to constant, the motor speed will be difficult to increase during acceleration due to friction, while over-braking may occur during deceleration. Therefore, at time x94, if the motor torque and load torque are balanced, the motor 10 stops. Furthermore, at time x96, after the wall collision determination time Xth has elapsed from the time x94 when the motor 10 stops, even if the stop roller 26 is positioned closer to the valley 212 than the peak 215, it may be mistakenly determined to have reached the wall on the valley 211 side, resulting in incorrect reference position learning. Additionally, assuming the target current I... * The value is set to the degree to which wall collision control can be achieved beyond the peak 215 at room temperature.

[0068] In this embodiment, such as Figure 9 As shown, at time x10, if wall-collision control is initiated, the drive mode is set to feedback mode, and motor 10 is driven by two-phase power. The motor speed SP is greater than the target speed SP. * When acceleration requests are made at times x10-x11, x12-x13, x14-x15, and x16-x17, the motor speed SP is the target speed SP. * The times x11 to x12, x13 to x14, and x15 to x16 above are the times when deceleration is requested.

[0069] When accelerating the request, the target current I will be... * Set a target acceleration value I2 at low temperature that is larger than the target acceleration value I1 at room temperature. When a deceleration request is made, the target current I... * Set the deceleration target value at low temperature I4 to be smaller than the deceleration target value I3 at room temperature. This is achieved by adjusting the target current I during acceleration. * The temperature is higher than at room temperature, resulting in greater driving torque, which increases the target current I during deceleration. * The temperature is lower than at room temperature, reducing braking torque and preventing over-braking. This allows the system to enter the next acceleration control cycle while still under the residual inertial force of the motor 10.

[0070] Therefore, by relying on inertial force, the motor torque is prevented from easily decreasing near the phase switching point during two-phase energization, thus preventing stalling at that position. Consequently, at low temperatures, during wall-blocking control towards the valley 211 from the state of the stop roller 26 in the valley 212, stalling will not occur midway towards the peak 215, allowing for proper learning of the reference position. Furthermore, if the peak 215 is exceeded, the stop roller 26 is driven towards the valley 211 by the spring force of the stop spring 25, preventing stalling due to insufficient torque. Figure 9 The description of what happened after crossing peak 215 is omitted in the text.

[0071] In addition, at room temperature, by using the target current I* The target acceleration value I1 and the target deceleration value I3 at room temperature are set. During acceleration, the torque is not increased, and during deceleration, the braking torque is not suppressed. This prevents a decrease in durability in wall collision control caused by unnecessarily increasing the torque at room temperature.

[0072] As explained above, the gear shift control device 40 controls the drive of the motor 10, which has motor windings 11, and includes a drive control unit 51 and a parameter setting unit 55. The drive control unit 51 controls the drive of the motor 10. The parameter setting unit 55 sets control parameters for the drive control of the motor 10 based on the system temperature thsys, in a manner that allows at least one of the motor torque and the motor speed to be changed. Therefore, the drive of the motor 10 can be appropriately controlled according to the system temperature thsys.

[0073] When the system temperature thsys is determined to be low, the parameter setting unit 55 sets the control parameter in a manner that reduces the braking torque during deceleration requests compared to that at normal temperatures. Specifically, in this embodiment, the control parameter is the target current I. * When the temperature is determined to be low, the parameter setting unit 55 sets the target current I during the deceleration request. * Smaller than at room temperature. In this embodiment, the target current I is reduced when a deceleration request is made under conditions determined to be low temperature. * This reduces braking torque. Therefore, it prevents the motor 10 from stopping at an unintended location due to sudden deceleration when a deceleration request is made, and allows the motor 10 to continue driving appropriately.

[0074] When the system temperature thsys is determined to be low, the parameter setting unit 55 sets the control parameters in a manner that increases the drive torque during acceleration requests compared to normal temperatures. Specifically, the control parameter in this embodiment is the target current I. * When the temperature is determined to be low, the parameter setting unit 55 sets the target current I during the acceleration request. * It is larger than at room temperature. In this embodiment, the target current I when an acceleration request is made under conditions determined to be low temperature is increased. * This increases the driving torque. Therefore, by increasing the driving torque during acceleration, and relying on inertia to pass through the motor angle where torque tends to decrease, it is possible to prevent stopping at unintended points and to ensure the proper and continuous operation of the motor 10.

[0075] The gear shift control device 40 is applied to the drive-by-wire shift system 1. In the learning process, which learns the position of the output shaft 15 that transmits the rotation of the motor 10 without using the position information of the output shaft 15, but instead learns the position of the P-wall based on the P-wall contact as the drive limit position of the motor 10, the parameter setting unit 55 sets the control parameters according to the system temperature thsys.

[0076] The information regarding the position of the output shaft 15 could be, for example, the detection value from the output shaft sensor. Without using the output shaft sensor's detection value, the ECU 50 cannot determine which of the valleys 211 or 212 the stop roller 26 is in when the start switch is turned on. In the case of learning processing from this state, it may be necessary to cross the peak 215.

[0077] Furthermore, from a durability point of view, it is preferable to operate at low speed and low torque during the learning process. On the other hand, when the motor 10 is driven at low speed and low torque, factors such as the torque of the two-phase drive tending to decrease near the angle of switching energized phases, and the increased slippage due to low temperature, combined with the fact that the motor 10 stops, may not have enough torque to restart and may not be able to pass the peak 215.

[0078] Therefore, in this embodiment, when learning is performed with two-phase power, both durability and motor controllability can be balanced by setting control parameters corresponding to the system temperature thsys.

[0079] <Second Implementation Method>

[0080] Figure 10 and Figure 11 This represents the second embodiment. In this embodiment, the parameter setting process differs from the above embodiment; the phase shift is changed as a control parameter. The phase shift is a positive advance angle and a negative lag angle, and its absolute value is the deviation from the reference value. In this embodiment, at low temperatures, the drive torque is increased by making the advance angle during acceleration larger than at normal temperatures. Furthermore, at low temperatures, the braking torque is reduced by making the lag angle during deceleration smaller than at normal temperatures, thus preventing over-braking.

[0081] based on Figure 10 The flowchart illustrates the parameter change processing. The processing of S321 and S322 is related to... Figure 8The processing in S301 and S302 is the same. When an acceleration request is made, if it is determined that the cryogenic flag flg is disabled (S322: Yes), i.e., at room temperature, proceed to S323 and set the phase shift to the acceleration advance angle F1 at room temperature (e.g., 0). If it is determined that the cryogenic flag flg is enabled (S322: No), proceed to S324 and set the phase shift to the acceleration advance angle F2 at cryogenic temperature (e.g., +1). Furthermore, if the advance angle at the time of the acceleration request is not changed according to temperature, the processing in S321 to S324 can be omitted.

[0082] The processing of S325 when a deceleration request is initiated (S321: No) and Figure 8 The process is the same as in S305. If it is determined that the low temperature flag flg is disabled (S325: Yes), that is, at room temperature, proceed to S326 and set the phase shift to the deceleration hysteresis angle F3 at room temperature (e.g., -2). If it is determined that the low temperature flag flg is enabled (S325: No), set the phase shift to the deceleration hysteresis angle F4 at low temperature (e.g., -1).

[0083] Figure 11 This describes the motor drive processing in this embodiment. In the timing diagram, the example shown is that the advance angle is set to 0 during acceleration, regardless of whether it is at room temperature or low temperature. Figure 11 In the diagram, solid lines represent phase shift at low temperatures, and dashed lines represent phase shift at room temperature.

[0084] If wall-blocking control begins at time x20, the drive mode is set to feedback mode, and motor 10 is driven by two-phase power. The motor speed SP is greater than the target speed SP. * When acceleration is requested at times x20-x21, x22-x23, x24-x25, and x26-x27, the motor speed SP is the target speed SP. * The times x21 to x22, x23 to x24, and x25 to x26 above are the times when deceleration is requested.

[0085] In this embodiment, when a deceleration request is made, the hysteresis angle at low temperature is smaller than that at normal temperature. As a result, by preventing excessive braking, the next acceleration control can be initiated under the residual inertial force of the motor 10, without stalling midway towards the peak 215, and the reference position can be learned appropriately.

[0086] In this embodiment, the control parameter is the hysteresis angle. When the temperature is determined to be low, the parameter setting unit 55 makes the hysteresis angle at the time of deceleration request smaller than that at normal temperature. In this embodiment, by reducing the hysteresis angle at the time of deceleration request, the braking torque is reduced. As a result, it is possible to prevent the motor 10 from stopping at an unintended location due to sudden deceleration at the time of deceleration request, and the drive of the motor 10 can be appropriately continued.

[0087] Furthermore, the control parameter is the advance angle. When a low temperature is detected, the parameter setting unit 55 increases the advance angle during acceleration requests compared to normal temperatures. In this embodiment, by increasing the advance angle during acceleration requests, the drive torque is increased. Therefore, by increasing the drive torque during acceleration, the motor can be driven through angles where torque tends to decrease due to inertia, preventing unintended stops and ensuring proper and continuous drive of the motor 10. This achieves the same effect as the embodiment described above.

[0088] <Third Implementation Method>

[0089] Figure 12 and Figure 13 This represents the third embodiment. In this embodiment, the parameter setting process differs from the embodiments described above; the target speed SP is changed as a control parameter. * At low temperatures, by increasing the target velocity SP * It is larger than at room temperature, and is set to the same motor speed SP as at room temperature.

[0090] based on Figure 12 The flowchart illustrates the parameter change handling. S341 and Figure 8 The process is the same as in S302. If the low-temperature flag flg is determined to be disabled (S341: Yes), proceed to S342 and set the target speed SP. * Set the target speed SP at room temperature * 1 (e.g., 300 [rpm]). If the low temperature flag flg is determined to be enabled (S341: No), proceed to S343 and set the target speed SP. * Set the target speed SP at low temperature * 2 (e.g., 350 [rpm]).

[0091] Figure 13 This describes the motor drive processing in this embodiment. The drive mode is set to feedback mode, and the motor 10 is driven by two-phase power supply. Time x30-x31, time x32-x33, time x34-x35, and time x36-x37 are acceleration requests, while time x31-x32, time x33-x34, and time x35-x36 are deceleration requests.

[0092] If wall-collision control begins at time x30, the drive mode is set to feedback mode, and motor 10 is driven by two-phase power. In this embodiment, the target speed SP at low temperature is achieved... * 2 compared to the target speed at room temperature SP * 1. Set the motor speed SP to the same as at room temperature. By increasing the motor speed SP, the time until the motor speed SP becomes 0 when a deceleration request is made is longer. Therefore, the next acceleration control can be entered under the residual inertial force of the motor 10, and there will be no pause in the middle of moving towards the peak 215. The reference position can be learned appropriately.

[0093] In this embodiment, the control parameter is the target speed SP of motor 10. * When the system temperature thsys is determined to be low, the parameter setting unit 55 sets the target speed SP. * The torque is greater than at room temperature. Therefore, by relying on inertia to pass through a motor angle where torque easily decreases, it is possible to prevent unintended stops and ensure proper and continuous drive of the motor 10. Furthermore, it achieves the same effect as the embodiment described above.

[0094] In this implementation, the shift-by-wire system 1 corresponds to the "power transmission switching system," the shift gear control device 40 corresponds to the "motor control device," and the shift-by-wire ECU 50 corresponds to the "control unit." Here, the power transmission switching system is a shift gear switching system, but in a broader sense, it can also be a system that switches power transmission states, such as switching the drive source in a hybrid vehicle.

[0095] <Other Implementation Methods>

[0096] At low temperatures, in the first embodiment, the target current is changed as a control parameter; in the second embodiment, the lag angle and advance angle (i.e., phase shift) are changed as control parameters; and in the third embodiment, the target velocity is changed. In other embodiments, multiple embodiments can be combined. For example, at low temperatures, the target current, phase shift, and target velocity can all be changed. Alternatively, control parameters other than the target current, phase shift, and target velocity can also be changed.

[0097] In the above embodiment, during reference position learning in two-phase power-on, the control parameters are changed at low temperatures. In other embodiments, reference position learning can also be performed using other power-on modes such as single-phase power-on. Alternatively, when learning a reference position based on wall contact to the side that does not need to cross the peak, based on the output shaft sensor's detection value, no temperature-based control parameter change is performed; however, when the output shaft sensor malfunctions or its detection value cannot be used, the control parameters are changed at low temperatures. Furthermore, when driving the motor for purposes other than reference position learning, the control parameters are changed at low temperatures.

[0098] In the above embodiment, the motor is a switched reluctance motor. In other embodiments, the motor may be a motor other than a switched reluctance motor, such as a DC brushless motor, and the number of magnetic poles and other parameters may be arbitrarily set.

[0099] In the above embodiment, the rotary position sensor is an encoder. In other embodiments, the rotary position sensor may also be a sensor other than an encoder, such as a resolver. In the above embodiment, two recesses are provided on the stop plate. In other embodiments, the number of recesses is not limited to two; for example, a recess may be provided for each gear position. Furthermore, the gear shifting mechanism, parking lock mechanism, etc., may also differ from those in the above embodiment.

[0100] In the above embodiments, a speed reducer is provided between the motor shaft and the output shaft. Details regarding the speed reducer are not mentioned in the above embodiments; for example, it can be any structure, such as a cycloidal gear, a planetary gear, a spur gear that transmits torque from a reduction mechanism substantially coaxial with the motor shaft to the drive shaft, or a combination thereof. Furthermore, in other embodiments, the speed reducer between the motor shaft and the output shaft may be omitted, or a mechanism other than a speed reducer may be provided. In the above embodiments, the motor control device is applied to the gear shifting system. In other embodiments, the motor control device may also be applied to a device other than the gear shifting system.

[0101] The control unit and method described in this disclosure can also be implemented using a dedicated computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and method described in this disclosure can also be implemented using a dedicated computer configured with a processor using one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in this disclosure can also be implemented using one or more dedicated computers configured with a combination of a processor and memory programmed to perform one or more functions and a processor containing one or more hardware logic circuits. Furthermore, the computer program can also be stored as instructions executable by a computer on a computer-readable non-transitional tangible recording medium. As described above, this disclosure is not limited to the above embodiments and can be implemented in various ways without departing from its spirit.

[0102] This disclosure is described based on embodiments. However, this disclosure is not limited to these embodiments and structures. This disclosure also includes various modifications and equivalent variations. In addition, various combinations and methods, as well as other combinations and methods that include only one element, more elements, or fewer elements, also fall within the scope and spirit of this disclosure.

Claims

1. A motor control device for controlling the drive of a motor having motor windings, characterized in that, have: A drive control unit that controls the drive of the motor; as well as The parameter setting unit sets the control parameters for the drive control of the motor in a manner that allows at least one of the motor torque and the motor speed to change based on the system temperature. When the motor is controlled to maintain its rotational speed by repeatedly performing acceleration and deceleration control, If the system temperature is determined to be at room temperature, the parameter setting unit does not suppress the braking torque when a deceleration request is made using parameters specified for room temperature. When the system temperature is determined to be low, the parameter setting unit sets the control parameter in such a way that the braking torque at the time of deceleration request is smaller than that at normal temperature.

2. The motor control device according to claim 1, characterized in that, The control parameter is the target current. When the temperature is determined to be low, the parameter setting unit makes the target current when a deceleration request is made smaller than that at normal temperature.

3. The motor control device according to claim 1, characterized in that, The control parameter is the hysteresis angle. When the temperature is determined to be low, the parameter setting unit makes the hysteresis angle at the time of the deceleration request smaller than that at normal temperature.

4. The motor control device according to claim 1, characterized in that, When the system temperature is determined to be low, the parameter setting unit sets the control parameters in a manner that makes the drive torque during acceleration requests greater than that at normal temperature.

5. The motor control device according to claim 4, characterized in that, The control parameter is the target current. When the temperature is determined to be low, the parameter setting unit makes the target current when the acceleration request is made larger than that at normal temperature.

6. The motor control device according to claim 4, characterized in that, The control parameter is the advance angle. When the temperature is determined to be low, the parameter setting unit makes the advance angle during the acceleration request larger than that at normal temperature.

7. The motor control device according to claim 1, characterized in that, The control parameter is the target speed of the motor. When the system temperature is determined to be low, the parameter setting unit increases the target speed compared to that at normal temperature.

8. The motor control device according to any one of claims 1 to 7, characterized in that, The motor control device is used in the power transmission switching system. When the position information of the output shaft transmitting the rotation of the motor is not used, but the motor is driven by setting the number of energized phases to a constant and switching the energized phases during the learning process of learning the drive limit position of the motor, the parameter setting unit sets the control parameters according to the system temperature.

Images