Motor torque control device and motor speed control device

Abstract

To provide a torque control device of a motor capable of controlling torque and speed only by setting a limit position range and a limit speed range without providing a specific position limit device.SOLUTION: A torque control device of a motor includes a speed deviation calculator 11, a speed command value calculator 12, a position deviation calculator 2, a position command calculator 3, a position limiter 4, and a position control unit 5 for controlling a motor position from a motor position command value. The position limiter 4 sets the maximum value as the motor position command value when the position command value is larger than the maximum value in a limit position range, sets the minimum value as the motor position command value when the value is smaller than the minimum value, and sets the position command value calculated from the speed command value as the motor position command value when the value is within the limit position range.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a torque control device and a speed control device for a motor.

Background Art

[0002] In the table drive of a machine tool, a ball screw is connected to a motor to realize linear motion. In such a mechanical device that performs linear motion, if the table tries to move beyond the movement limit point due to an operation error or the like, the device may be damaged. To prevent such damage to the device, for example, a limit switch is provided at a position before the movement limit point.

[0003] ​​​​​​​​​​​​​​​​​​​​​​​ However, this method of stopping a motor using limit switches requires both the limit switch itself and the wiring from the limit switch to the motor control device. Furthermore, the distance the table travels from the moment the limit switch is activated until it stops must also be considered, requiring the limit switch to be placed further before the stopping point by the distance traveled, thus complicating the device configuration. Therefore, there is still room for improvement in motor control for machine tool table drives and the like.

[0006] Therefore, the present invention provides a motor torque control device and a motor speed control device that can control the torque and speed of a motor simply by setting a limited position range or a limited speed range to be restricted, without the need to install a specific position limiting device. [Means for solving the problem]

[0007] A motor torque control device according to one aspect of the present invention is: A motor torque control device that controls the torque of a motor within a limited position range which is within a preset range of a first minimum value and a first maximum value, based on a torque command value input from an external source, A position detector for detecting the position of the motor, A speed calculator that calculates the motor speed by differentiating the aforementioned position, A speed deviation calculator that calculates a speed deviation value indicating how much the motor should be accelerated or decelerated from its current speed based on the torque command value, A speed command value calculator that calculates a speed command value based on the speed deviation value and the motor speed, A position deviation calculator that calculates a position deviation value indicating how far the motor should be moved from its current position based on the speed command value, A position command calculator that calculates a position command value by adding the position to the position deviation value, A position limiter that calculates a motor position command value to limit the position of the motor according to the position command value and the limit position, It includes a position control unit that controls the position of the motor based on the motor position command value, The aforementioned position limiter is If the position command value is greater than the first maximum value, the first maximum value is set as the motor position command value. If the position command value is smaller than the first minimum value, the first minimum value is set as the motor position command value. If the position command value is within the limited position range, the position command value calculated based on the speed command value is set as the motor position command value.

[0008] A motor speed control device according to one aspect of the present invention is: A motor speed control device that controls the speed of a motor within a limited position range which is within a preset range of a first minimum value and a first maximum value, based on a speed command value input from an external source, A position detector for detecting the position of the motor, A position deviation calculator that calculates a position deviation value indicating how far the motor should be moved from its current position based on the speed command value, A position command calculator that calculates a position command value by adding the position to the position deviation value, A position limiter that calculates a motor position command value to limit the position of the motor according to the aforementioned limit position, It includes a position control unit that controls the position of the motor based on the motor position command value, The aforementioned position limiter is If the position command value is greater than the first maximum value, the first maximum value is set as the motor position command value. If the position command value is smaller than the first minimum value, the first minimum value is set as the motor position command value. If the position command value is within the limited position range, the position command value calculated based on the speed command value is set as the motor position command value. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a torque control device and a speed control device for a motor that can control the torque and speed of the motor without providing a specific position limiting device, simply by setting a restricted position range or a restricted speed range to be restricted.

Brief Description of the Drawings

[0010] [Figure 1] It is a block diagram showing the configuration of a speed control device for a motor according to a first embodiment of the present invention. [Figure 2] It is a block diagram of the position control unit in FIG. 1. [Figure 3] (a) to (d) are graphs showing the simulation results of the motor position and motor speed controlled by the motor speed control device. [Figure 4] It is a block diagram showing the configuration of a torque control device for a motor according to a second embodiment of the present invention. [Figure 5] It is a block diagram of the speed command value calculator in FIG. 4. [Figure 6] (a) to (g) are graphs showing the simulation results of the motor position, motor speed, and motor torque command value controlled by the motor torque control device.

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the embodiments, the description of members having the same reference numerals as those already described will be omitted for the sake of convenience. Also, the dimensions of each member shown in these drawings may be different from the actual dimensions of each member for the sake of convenience of explanation.

[0012] (First Embodiment) Figure 1 is a block diagram showing the configuration of a motor speed control device according to the first embodiment of the present invention. The motor speed control device according to the first embodiment is a control device that can control the speed of a motor within a set limited position range by pre-setting the movable range of the device (hereinafter also referred to as the "limited position range") from an external source in a device on which a motor is mounted.

[0013] As shown in Figure 1, the motor speed control device (hereinafter also referred to as motor speed control device 1) comprises a position deviation calculator 2, a position command calculator 3, a position limiter 4, a position control unit 5, a position detector 6, and a motor speed calculator 7.

[0014] In a motor speed control device 1 with this configuration, a speed command value Vc for controlling the motor speed V of the motor M and a limiting position PL for limiting the motor position P of the motor M are input from an external source. Based on these external inputs of the speed command value Vc and limiting position PL, the motor speed control device 1 controls the speed of the motor M under a desired speed and a constant position limit.

[0015] The desired speed command value Vc, provided externally, is input to the position deviation calculator 2. Based on the input speed command value Vc, the position deviation calculator 2 calculates a position deviation value Pd1 that indicates how far the motor M needs to be moved from its current position.

[0016] The calculated position deviation value Pd1 is input to the position command calculator 3. The position command calculator 3 is input to the motor position P of the motor M detected by the position detector 6. The position detector 6 is composed of, for example, an encoder capable of detecting the position of the motor M. The position command calculator 3 adds the position deviation value Pd1 and the motor position P to calculate the position command value Pc based on the speed command value Vc.

[0017] The calculated position command value Pc is input to the position limiter 4. The position limiter 4 is input to the desired limit position PL for limiting the motor position P. Based on the position command value Pc and the limit position PL, the position limiter 4 calculates a motor position command value Pmc so as to limit the motor position P according to the position command value Pc and the limit position PL.

[0018] The calculated motor position command value Pmc is input to the position control unit 5. The position control unit 5 controls the motor position P of the motor M based on the motor position command value Pmc.

[0019] Figure 2 is a block diagram of the position control unit 5. As shown in Figure 2, the position control unit 5 includes a position controller 51, a speed controller 52, and a torque controller 53.

[0020] The motor position command value Pmc calculated by the position limiter 4 is input to the position controller 51 of the position control unit 5. The motor position P of the motor M detected by the position detector 6 is input to the position controller 51. The position controller 51 calculates a position deviation value Pd2, which indicates how much the current position of the motor M should be moved, by subtracting the current motor position P from the motor position command value Pmc. Based on the calculated position deviation value Pd2, the position controller 51 calculates the motor speed command value Vmc.

[0021] The calculated motor speed command value Vmc is input to the speed controller 52. The speed controller 52 has the motor speed V of motor M, calculated by the motor speed calculator 7, as input. The motor speed calculator 7 calculates the motor speed V by differentiating the motor position P detected by the position detector 6. The speed controller 52 calculates a speed deviation value Vd0, which indicates how much to accelerate or decelerate the current speed of motor M, by subtracting the current motor speed V from the motor speed command value Vmc. Based on the calculated speed deviation value Vd0, the speed controller 52 calculates the motor torque command value Tmc.

[0022] The motor torque command value Tmc is input to the torque controller 53. Based on the motor torque command value Tmc, the torque controller 53 controls the motor M so that the desired (as per the command value) motor torque T is output.

[0023] Then, the motor position P, which has been moved by the motor torque T output from the motor M, is detected by the position detector 6, and the position is controlled so that the motor position command value Pmc matches the current motor position P of the motor M. In this way, the control loop by the motor speed control device 1 is executed.

[0024] Next, we will explain the calculation of the position control loop in the position controller 51. In the motor speed control device 1, for example, if the position controller 51 is configured as a proportional controller and its gain is G, the calculation of the position control loop in the position controller 51 is as follows.

[0025] Motor position command value Pmc - Motor position P = Position deviation value Pd² ... (1) Position deviation value Pd² × proportional controller gain G = motor speed command value Vmc...(2)

[0026] From equations (1) and (2), the motor position command value Pmc can be calculated inversely from the motor speed command value Vmc as follows. Position deviation value Pd2 = Motor speed command value Vmc / Proportional controller gain G...(3) Motor position command value Pmc = position deviation value Pd2 + motor position P...(4)

[0027] In this invention, a position command value Pc is calculated based on the speed command value Vc, using the relationship between equations (3) and (4) above, with respect to an externally supplied speed command value Vc. Position deviation value Pd1 based on speed command value Vc = speed command value Vc / G ... (5) Position command value Pc based on speed command value Vc = Position deviation value Pd1 based on speed command value Vc + Motor position P...(6)

[0028] Then, the position is restricted based on the position command value Pc, which is determined by the speed command value Vc, using the position limiter 4 based on the limit position PL set externally, and the motor position command value Pmc is determined. When the motor position P of motor M is controlled based on this motor position command value Pmc, Motor speed command value Vmc = Position deviation Pd² × Proportional controller gain G = (Motor position command value Pmc - Motor position P) × Proportional controller gain G

[0029] Here, if the position command value Pc is within the restricted position range, that is, if the position command value Pc calculated based on the speed command value Vc does not fall under the position restriction imposed by the restricted position PL, then the motor position command value Pmc = position command value Pc based on the speed command value Vc. In this case, the position command value Pc calculated based on the speed command value Vc is set as the motor position command value Pmc.

[0030] Therefore, Motor speed command value Vmc = (Position command value Pc based on speed command value Vc - motor position P) × proportional controller gain G = {(Position deviation value Pd1 based on speed command value Vc + motor position P) - motor position P} × proportional controller gain G = (Position deviation value Pd1 based on speed command value Vc) × Gain G of proportional controller = (Speed ​​command value Vc / G) × Proportional controller gain G = Speed ​​command value Vc As a result, the motor speed command value Vmc matches the speed command value Vc, and the motor M is controlled based on this motor speed command value Vmc, so that the motor M is controlled to the speed specified by the motor speed command value Vmc, that is, the speed specified by the speed command value Vc.

[0031] In contrast, if the position command value Pc is not within the restricted position range, that is, if the position command value Pc calculated based on the speed command value Vc is subject to the position restriction by the restricted position PL, the motor position command value Pmc becomes the position restriction value (restricted position PL). For example, if the position command value Pc is greater than the maximum value of the restricted position range, the maximum value is set as the motor position command value Pmc. If the position command value Pc is less than the minimum value of the restricted position range, the minimum value is set as the motor position command value Pmc. Then, the position control of the motor M is performed based on the restricted position PL (maximum value, minimum value), and the motor position P is controlled to the restricted position PL.

[0032] This allows the machine to set the limit position PL to the upper and lower limits of its movable range. Speed ​​control will be performed within the movable range, and when the limit is reached, the machine will be positioned at the limit position.

[0033] Furthermore, the limit position PL can also be determined based on a predetermined threshold, a predetermined table value, a predetermined function value, etc., to set the limit value of the motor position P. In this case, "predetermined" means, needless to say, that it can be arbitrarily determined, and furthermore, it also means that it can be arbitrarily set at any point in time, such as during manufacturing, testing, shipping, or use of the motor speed control device.

[0034] Figure 3 is a graph showing the simulation results of motor position P and motor speed V controlled by the motor speed control device 1. Figure 3(a) is a graph showing the change in speed command value Vc. Figure 3(b) is a graph showing the change in position command value Pc based on speed command value Vc. Figure 3(c) is a graph showing the change in motor position command value Pmc and motor position P. Figure 3(d) is a graph showing the change in motor speed command value Vmc and motor speed V.

[0035] In this simulation, 2500 min -1 A trapezoidal driving pattern was implemented at speeds up to a certain point. The limiting position range was set with a minimum value of 0 rad and a maximum value of 19 rad.

[0036] As shown in Figures 3(a) to (d), when the speed command value Vc increases, the position command value Pc, motor position command value Pmc, motor position P, motor speed command value Vmc, and motor speed V also increase in response to the increase in the speed command value Vc. When the speed command value Vc increases and the position command value Pc based on the speed command value Vc reaches the maximum value of 19 rad in the limited position range, the motor position command value Pmc is limited to the maximum value of 19 rad (see Figure 3(c)). When the motor position command value Pmc reaches the maximum value of 19 rad, the motor speed command value Vmc decreases, and the motor M stops at the position limited to the maximum value of 19 rad in the limited position range (see Figure 3(d)).

[0037] Similarly, in the reverse direction, when the speed command value Vc increases in the negative direction and the position command value Pc based on the speed command value Vc reaches the minimum value of 0 rad within the limited position range, the motor position command value Pmc is limited to the minimum value of 0 rad (see Figure 3(c)). When the motor position command value Pmc reaches the minimum value of 0 rad, the motor speed command value Vmc increases, and the motor M stops at the position limited to the minimum value of 0 rad within the limited position range (see Figure 3(d)).

[0038] As described above, in the motor speed control device 1 of the first embodiment, the motor speed command value Vmc is calculated by performing a reverse calculation of the motor speed command value Vmc from the motor position command value Pmc in the position control system. Based on the speed command value Vc, the position command value Pc is calculated based on the speed command value Vc, the motor position command value Pmc is obtained by applying position restrictions, and the motor speed command value Vmc is calculated based on the motor position command value Pmc.

[0039] Therefore, if the position command value Pc is not subject to the position limit imposed by the limit position PL, the motor position command value Pmc becomes the position command value Pc based on the speed command value Vc, and the motor speed command value Vmc is output according to the speed command value Vc, and the motor M is speed-controlled to the motor speed V according to the speed command value Vc. On the other hand, if the position command value Pc is subject to the position limit imposed by the limit position PL, the motor position command value Pmc becomes the position limit value, and the motor position P of the motor M is controlled to the position limit value. Thus, if the position limit values ​​are set as the upper and lower limits of the movable range of the controlled machine, speed control will be performed within the limited position range, and when the limit of the limited position range is reached, the position will be controlled to the movable limit position.

[0040] As described above, the motor speed control device 1 according to this embodiment can achieve speed control with a motor position limiting function with a simple configuration that calculates a position command value Pc based on a speed command value Vc, applies position limiting to obtain a motor position command value Pmc, and controls the position of the motor M based on the motor position command value Pmc. If the set limit position range is not exceeded, the motor M can be controlled at a speed V according to the set speed command value Vc, and when the limit position of the limit position range is reached, the motor M can be stopped at the limit position. In this way, the motor speed can be controlled simply by setting the limit position range to be limited, without having to install a specific position limiting device such as a limit switch.

[0041] (Second embodiment) Figure 4 is a block diagram showing the configuration of a motor torque control device according to the second embodiment of the present invention. Figure 5 is a block diagram of the speed command value calculator 12 in Figure 4. The motor torque control device according to the second embodiment is a control device that can control the torque of a motor within a set speed limit range and a set position limit range by pre-setting the speed range of the equipment (hereinafter also referred to as the "speed limit range") and the movable range of the equipment (hereinafter also referred to as the "position limit range") from an external source in equipment on which a motor is mounted.

[0042] As shown in Figure 4, the torque control device for motor M (hereinafter also referred to as motor torque control device 10) includes a speed deviation calculator 11, a speed command value calculator 12, a position deviation calculator 2, a position command calculator 3, a position limiter 4, a position control unit 5, a position detector 6, and a motor speed calculator 7. The speed command value calculator 12 includes a first speed command value calculator 121 and a speed limiter 122, as shown in Figure 5. The position control unit 5 has the same configuration as the position control unit 5 of the motor speed control device 1 of the first embodiment shown in Figure 2.

[0043] In a motor torque control device 10 with this configuration, a torque command value Tc for controlling the motor torque T of the motor M, a limiting speed VL for limiting the motor speed V of the motor M, and a limiting position PL for limiting the motor position P of the motor M are input from an external source. As a result, the motor torque control device 10 controls the torque of the motor M under the desired torque and constant speed and position limits.

[0044] The desired torque command value Tc, which is provided from an external source, is input to the speed deviation calculator 11. Based on the input torque command value Tc, the speed deviation calculator 11 calculates a speed deviation value Vd1 that indicates how much the motor M needs to be accelerated or decelerated from its current speed.

[0045] The calculated speed deviation value Vd1 is input to the speed command value calculator 12. The speed command value calculator 12 has the motor speed V of motor M, calculated by the motor speed calculator 7, as input. The speed command value calculator 12 also has a limiting speed VL, which is used to limit the motor speed V, as input. The speed command value calculator 12 is a calculator that can control the speed of motor M within a preset limiting speed range.

[0046] As shown in Figure 5, the speed deviation value Vd1 calculated by the speed deviation calculator 11 is input to the first speed command value calculator 121 of the speed command value calculator 12. The motor speed V of motor M calculated by the motor speed calculator 7 is also input to the first speed command value calculator 121. The desired limiting speed VL to restrict the motor speed V is input to the speed limiter 122 of the speed command value calculator 12.

[0047] The first speed command value calculator 121 adds the motor speed V to the speed deviation value Vd1 to calculate the first speed command value Vc0 based on the torque command value Tc.

[0048] The calculated first speed command value Vc0 is input to the speed limiter 122. Based on the first speed command value Vc0 and the speed limit VL, the speed limiter 122 calculates a speed command value Vc to limit the motor speed V of the motor M according to the first speed command value Vc0 and the speed limit VL.

[0049] The calculated speed command value Vc is input to the position deviation calculator 2. Returning to Figure 4, the position deviation calculator 2 calculates a position deviation value Pd1 that indicates how far the motor M needs to be moved from its current position, based on the input speed command value Vc. The configuration after the position deviation calculator 2 (position command calculator 3, position limiter 4, and position control unit 5) is the same as the configurations of the first embodiment shown in Figures 1 and 2. Therefore, their explanations will be omitted.

[0050] Next, the calculation of the speed control loop in the speed controller 52 and the position control loop in the position controller 51 of the motor torque control device 10 will be explained. In the motor torque control device 10, for example, the speed controller 52 and the position controller 51 are configured as proportional controllers, and the gain of the speed controller 52 is GV and the gain of the position controller 51 is GP. In this case, the calculation of the speed control loop in the speed controller 52 and the position control loop in the position controller 51 will be as follows.

[0051] First speed command value Vc0 - motor speed V = speed deviation value Vd1...(1) Speed ​​deviation value Vd1 × Speed ​​controller gain GV = Torque command value Tc...(2) Motor position command value Pmc - Motor position P = Position deviation value Pd2 ... (3) Position deviation value Pd2 × position controller gain GP = motor speed command value Vmc...(4)

[0052] From equations (1) to (4), the first speed command value Vc0 can be calculated from the torque command value Tc, and the motor position command value Pmc can be calculated from the motor speed command value Vmc as follows. Speed ​​deviation value Vd1 = Torque command value Tc / Speed ​​controller gain GV...(5) First speed command value Vc0 = speed deviation value Vd1 + motor speed V···(6) Position deviation value Pd2 = Motor speed command value Vmc / Gain of position controller GP ... (7) Motor position command value Pmc = position deviation value Pd2 + motor position P...(8)

[0053] In this invention, a first speed command value Vc0 is calculated based on the torque command value Tc, using the relationship between equations (5) and (8) above, with respect to an externally supplied torque command value Tc. Speed ​​deviation value Vd1 based on torque command value Tc = Torque command value Tc / Speed ​​controller gain GV First speed command value Vc0 based on torque command value Tc = Speed ​​deviation value Vd1 based on torque command value Tc + Motor speed V

[0054] Then, the speed is limited based on the speed limit VL set externally by the speed limiter 122, with respect to the first speed command value Vc0 which is based on the obtained torque command value Tc, and the speed command value Vc after the limit is determined.

[0055] Similarly, the position command value Pc is calculated from the restricted speed command value Vc. Position deviation value Pd1 based on the limited speed command value Vc = Limited speed command value Vc / Position controller gain GP Position command value Pc based on the limited speed command value Vc = Position deviation value Pd1 based on the limited speed command value Vc + Motor position P

[0056] Then, based on the determined restricted speed command value Vc, the position command value Pc is restricted by the position limiter 4 based on the restricted position PL set externally, and the motor position command value Pmc is determined.

[0057] When the motor position P of motor M is controlled based on this motor position command value Pmc, Motor speed command value Vmc = Position deviation Pd2 × Position controller gain GP = (Motor position command value Pmc - Motor position P) × Position controller gain GP Torque command value Tc = Speed ​​deviation Vd1 × Speed ​​controller gain GV = (First speed command value Vc0 - Motor speed V) × Speed ​​controller gain GV

[0058] Here, if the position command value Pc is within the limited position range, that is, if the position command value Pc calculated based on the torque command value Tc does not exceed the position limit set by the limited position PL, then the motor position command value Pmc = position command value Pc based on the limited speed command value Vc. In this case, the position command value Pc calculated based on the speed command value Vc is set as the motor position command value Pmc.

[0059] Therefore, Motor speed command value Vmc = (Motor position command value Pmc - Motor position P) × Position controller gain GP = (Position command value Pc based on the limited speed command value Vc - motor position P) × position controller gain GP = {(Position deviation value Pd1 based on the limited speed command value Vc + motor position P) - motor position P} × position controller gain GP = (Position deviation value Pd1 based on the limited speed command value Vc) × Position controller gain GP = (Restricted speed command value Vc / Position controller gain GP) × Position controller gain GP =Restricted speed command value Vc Therefore, the motor speed command value Vmc matches the speed command value Vc after the limit is reached.

[0060] Furthermore, if the first speed command value Vc0 is within the speed limit range, that is, if the first speed command value Vc0 calculated based on the torque command value Tc does not exceed the speed limit VL, then the speed command value Vc after the limit will be equal to the first speed command value Vc0. In this case, the first speed command value Vc0 calculated based on the torque command value Tc is set as the speed command value Vc.

[0061] Therefore, Motor torque command value Tmc = (Motor speed command value Vmc - Motor speed V) × Speed ​​controller gain GV = (Restricted speed command value Vc - Motor speed V) × Speed ​​controller gain GV = (First speed command value Vc0 - Motor speed V) × Speed ​​controller gain GV = {(Speed ​​deviation value Vd1 based on torque command value Tc + motor speed V) - motor speed V} × speed controller gain GV = (Speed ​​deviation value Vd1 based on torque command value Tc) × Speed ​​controller gain GV = Torque command value Tc / Speed ​​controller gain GV × Speed ​​controller gain GV = Torque command value Tc As a result, the motor torque command value Tmc matches the torque command value Tc, and the motor M is torque-controlled based on this motor torque command value Tmc, so that the motor M is torque-controlled to the torque specified by the motor torque command value Tmc, that is, to the torque specified by the torque command value Tc.

[0062] On the other hand, if the first speed command value Vc0 is not within the speed limit range, that is, if the first speed command value Vc0 calculated based on the torque command value Tc is subject to the speed limit VL, then the speed command value Vc after the limit becomes the speed limit value (speed limit VL) and the speed is restricted. For example, if the first speed command value Vc0 is greater than the maximum value of the speed limit range, the maximum value is set as the speed command value Vc. If the first speed command value Vc0 is less than the minimum value of the speed limit range, the minimum value is set as the speed command value Vc. Then, speed control of the motor M is performed based on the speed limit VL (maximum value, minimum value), and the motor speed V is controlled to the speed limit VL.

[0063] Furthermore, if the position command value Pc is not within the limited position range, that is, if the position command value Pc calculated based on the torque command value Tc is subject to the position limit imposed by the limit position PL, the motor position command value Pmc becomes the position limit value (limit position PL). For example, if the position command value Pc is greater than the maximum value of the limited position range, the maximum value is set as the motor position command value Pmc. If the position command value Pc is less than the minimum value of the limited position range, the minimum value is set as the motor position command value Pmc. Then, the motor M's position is controlled based on the limit position PL (maximum value, minimum value), and the motor position P is controlled to the limit position PL.

[0064] This allows the machine to be positioned at the upper and lower limits of its movable range by setting the limit position PL to the upper and lower limits of the machine's movable range. Torque control will be performed within the movable range, and when the movable limit is reached, the machine will be controlled to the movable limit position.

[0065] Figure 6 is a graph showing the simulation results of the motor position P, motor speed V, and motor torque command value Tmc controlled by the motor torque control device 10. Figure 6(a) is a graph showing the change in the torque command value Tc. Figure 6(b) is a graph showing the change in the first speed command value Vc0 based on the torque command value Tc. Figure 6(c) is a graph showing the change in the speed command value Vc after the limit is reached. Figure 6(d) is a graph showing the change in the position command value Pc based on the speed command value Vc after the limit is reached. Figure 6(e) is a graph showing the change in the motor position command value Pmc and motor position P. Figure 6(f) is a graph showing the change in the motor speed command value Vmc and motor speed V. Figure 6(g) is a graph showing the change in the motor torque command value Tmc.

[0066] In this simulation, command operation was performed with a torque of ±20 Nm. The speed limit range was ±2500 min. -1 It is set to have a minimum position range of 0 rad and a maximum range of 10 rad.

[0067] As shown in Figures 6(a) to (c), the torque command value Tc increases, and the first speed command value Vc0 based on the torque command value Tc reaches the maximum value of the speed limit range, 2500 min. -1 When it rises, the limited speed command value Vc will reach a maximum of 2500 min -1 The motor position command value Pmc is limited to a maximum of 10 rad, when the torque command value Tc increases and the position command value Pc based on the limited speed command value Vc reaches the maximum value of 10 rad in the limited position range. (See Figures 6(d) and (e)). When the motor position command value Pmc reaches the maximum value of 10 rad, the motor speed command value Vmc decreases, and the motor M stops at the position limited to the maximum value of 10 rad in the limited position range. (See Figure 6(f)). In addition, the motor torque command value Tmc decreases in accordance with the decrease in the motor speed command value Vmc. (See Figure 6(g)).

[0068] Similarly, in the reverse direction of operation, the torque command value Tc increases in the negative direction, and the first speed command value Vc0 based on the torque command value Tc becomes the minimum value of the speed limit range -2500 min. -1When the speed increases, the limited speed command value Vc will be the minimum value of -2500 min -1 The motor position command value Pmc is limited to the minimum value of 0 rad (see Figures 6(a) to (c)). Also, when the torque command value Tc increases in the negative direction and the position command value Pc based on the limited speed command value Vc becomes the minimum value of 0 rad in the limited position range, the motor position command value Pmc is limited to the minimum value of 0 rad (see Figures 6(d) and (e)). When the motor position command value Pmc becomes the minimum value of 0 rad, the motor speed command value Vmc increases, and the motor M stops at the position limited to the minimum value of 0 rad in the limited position range (see Figure 6(f)). Also, the motor torque command value Tmc increases in accordance with the increase in the motor speed command value Vmc (see Figure 6(g)).

[0069] As described above, in the motor torque control device 10 of the second embodiment, the motor speed command value Vmc is calculated from the motor position command value Pmc in the position control system, and the motor torque command value Tmc is calculated from the motor speed command value Vmc in the speed control system by performing a reverse calculation. Based on the torque command value Tc, a first speed command value Vc0 based on the torque command value Tc is calculated, a speed limit is applied to obtain the speed command value Vc after the limit is applied, a position command value Pc based on the speed command value Vc after the limit is applied, a position limit is applied to obtain the motor position command value Pmc, a motor speed command value Vmc is calculated based on the motor position command value Pmc, and a motor torque command value Tmc is calculated based on the motor speed command value Vmc.

[0070] Therefore, when the position command value Pc is not subject to the position limit imposed by the limit position PL, and when the first speed command value Vc0 is not subject to the speed limit imposed by the limit speed VL, the motor torque command value Tmc = torque command value Tc, and a motor torque command value Tmc equal to the torque command value Tc is output, and the motor M is torque-controlled to the torque equal to the torque command value Tc.

[0071] In contrast, when the first speed command value Vc0 is subject to the speed limit VL, the speed command value Vc is limited to the speed limit value (speed limit VL). Furthermore, when the position command value Pc is subject to the position limit PL, the motor position command value Pmc becomes the position limit value, and the motor position P of the motor M is controlled to the position limit value. Therefore, if the position limit values ​​are set as the upper and lower limits of the movable range of the controlled machine, torque control will be performed within the limited position range, and when the limit of the limited position range is reached, the position will be controlled to the movable limit position.

[0072] As described above, the motor torque control device 10 according to this embodiment can realize torque control with motor position P and motor speed V limiting functions with a simple configuration: calculate a first speed command value Vc0 based on the torque command value Tc, apply speed limiting to obtain the limited speed command value Vc, calculate a position command value Pc based on the limited speed command value Vc, apply position limiting to obtain the motor position command value Pmc, and control the position of the motor M based on the motor position command value Pmc. Furthermore, if the set limited speed range and limited position range are not exceeded, the motor M can be torque-controlled with the motor torque T as specified by the set torque command value Tc. When the limits of the limited speed range and limited position range are reached, the speed of the motor M can be limited to the limited limit speed and the motor M can be stopped at the limited limit position. As a result, the torque of the motor can be controlled without providing a specific position limiting device such as a limit switch, simply by setting the limited speed range and limited position range that you want to limit.

[0073] Although embodiments of the present invention have been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of these embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications to the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and the scope of its equivalents. [Explanation of symbols]

[0074] 1. Motor speed control device 2 Position deviation calculator 3 Position command calculator 4. Position limiter 5 Position control unit 6. Position detector 7. Motor Speed ​​Calculator 10 Motor Torque Control Device 11 Speed ​​deviation calculator 12 Speed ​​command value calculator 51 Position controller 52 Speed ​​controller 53 Torque controller 121 First Speed ​​Command Value Calculator 122 Speed ​​limiter M Motor P Motor position Pc position command value Pd1, Pd2 positional deviations PL restriction position Pmc motor position command value Tc Torque Command Value Tmc Motor Torque Command Value V Motor Speed Vc speed command value Vc0 First speed command value Vd0, Vd1 Speed ​​deviation values Vmc Motor speed command value VL Speed ​​Limit

Claims

1. A motor torque control device that controls the torque of a motor so that the motor's position is limited to a restricted position range which is within a preset range of a first minimum value and a first maximum value, based on a torque command value input from an external source, A position detector for detecting the position of the motor, A speed calculator that calculates the motor speed by differentiating the aforementioned position, A speed deviation calculator that calculates a speed deviation value indicating how much the motor should be accelerated or decelerated from its current speed based on the torque command value, A speed command value calculator that calculates a speed command value based on the speed deviation value and the motor speed, A position deviation calculator that calculates a position deviation value indicating how far the motor should be moved from the position detected by the position detector, based on the speed command value, A position command calculator that calculates a position command value by adding the position to the position deviation value, A position limiter that calculates a motor position command value to limit the position of the motor according to the position command value and the limit position, It includes a position control unit that controls the position of the motor based on the motor position command value, The aforementioned position limiter is If the position command value is greater than the first maximum value, the first maximum value is set as the motor position command value. If the position command value is smaller than the first minimum value, the first minimum value is set as the motor position command value. A motor torque control device that, when the position command value is within the limited position range, sets the position command value calculated based on the speed command value as the motor position command value.

2. The position control unit, A position controller that calculates a motor speed command value based on the difference between the aforementioned position and the motor position command value, A speed controller that calculates a motor torque command value based on the difference between the motor speed command value and the motor speed, A motor torque control device according to claim 1, comprising: a motor torque controller that controls the motor based on the motor torque command value so that a torque equal to the motor torque command value is generated.

3. The speed command value calculator controls the speed of the motor within a speed limit range which is within the range of a preset first minimum value and first maximum value. The speed command value calculator is, A first speed command value calculator calculates a first speed command value by adding the motor speed to the speed deviation value, The system includes a first speed command value and a speed limiter that calculates the speed command value to limit the speed of the motor according to the speed limit, The aforementioned speed limiter, If the first speed command value is greater than the first maximum value, the first maximum value is set as the speed command value. If the first speed command value is smaller than the first minimum value, the first minimum value is set as the speed command value. The motor torque control device according to claim 1, wherein if the first speed command value is within the speed limit range, the first speed command value calculated based on the torque command value is set as the speed command value.

4. A motor speed control device that controls the speed of a motor so that the motor position is limited to a restricted position range which is within a preset range of a first minimum value and a first maximum value, based on a speed command value input from an external source, A position detector for detecting the position of the motor, A position deviation calculator that calculates a position deviation value indicating how far the motor should be moved from the position detected by the position detector, based on the speed command value, A position command calculator that calculates a position command value by adding the position to the position deviation value, A position limiter that calculates a motor position command value to limit the position of the motor according to the position command value and the limit position, It includes a position control unit that controls the position of the motor based on the motor position command value, The aforementioned position limiter is If the position command value is greater than the first maximum value, the first maximum value is set as the motor position command value. If the position command value is smaller than the first minimum value, the first minimum value is set as the motor position command value. A motor speed control device that, when the position command value is within the limited position range, sets the position command value calculated based on the speed command value as the motor position command value.

5. The position control unit, A position controller that calculates a motor speed command value based on the difference between the aforementioned position and the motor position command value, A motor speed calculator that calculates the motor speed by differentiating the aforementioned position, A speed controller that calculates a motor torque command value based on the difference between the motor speed command value and the motor speed, A motor speed control device according to claim 4, comprising: a torque controller that controls the motor based on the motor torque command value so that a torque is generated according to the motor torque command value.

Images