Motor control device and motor control method

Abstract

This suppresses the effects of noise contained in the signals used for motor control, enabling more precise motor control. [Solution] The motor control device 100 includes a first position controller 101 that calculates an angle command value for the angle at which the motor rotates based on an input position command value, a second position controller 105 that calculates a speed command value from the angle deviation relative to the motor using the angle command value calculated by the first position controller and an angle detection value that includes an angle error in the motor output, a state estimator 123 that derives an estimated angular velocity value of the motor by feedback control based on angular velocity information detected from the motor, a first speed controller 107 that calculates an angular velocity command value for the motor based on the speed command value, and a second speed controller 111 that calculates a current command value from the angular velocity deviation relative to the motor using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator.

Description

Technical Field

[0001] The present invention relates to a motor control device and a motor control method.

Background Art

[0002] Conventionally, motors have been used in various devices such as machine tools and inspection devices. The rotational speed of the motor is required to follow the speed command. In reality, the speed command for the motor and the detection signal from the detection device that detects the operating state of the motor may contain errors and noise. These can affect the angle and angular velocity during the operation of the motor.

[0003]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When controlling a motor with high precision, ensuring that the rotational speed follows the speed command precisely, it is necessary to suppress the effects of errors and noise as described above. Here, we consider a feedback-type configuration. The errors mentioned above include, for example, multiple periodic sinusoidal errors (linearity errors) corresponding to one rotation of the motor during angle detection. If speed control is performed by feeding back the angular velocity signal obtained by differentiating the angle signal without considering such errors, sound and vibration with a frequency proportional to the rotational speed will occur. In addition, as another type of error or noise, the speed command used to control the motor may contain high-frequency noise. If the rotational speed is controlled using a speed command containing such noise as is, high-frequency sound and vibration will occur. Furthermore, for example, in the configuration of Patent Document 1, there is a problem that tuning is not possible unless the motor is moving at a constant speed, which is a condition for calculating the error pattern. It is necessary to suppress the effects of errors and noise contained in the various signals used for motor control as described above, and to achieve more precise rotational control by ensuring that the rotational speed follows the command precisely. For example, the above-mentioned problems are particularly important for motors used in semiconductor exposure equipment and other applications that process workpieces at a constant speed. To achieve such fine and high-density imaging, more precise motor control technology is urgently needed.

[0006] Therefore, the present invention aims to provide a motor control device and a motor control method that suppress the effects of angular errors and noise contained in the signals used for motor control, thereby achieving more accurate motor control. [Means for solving the problem]

[0007] The present invention consists of the following configuration. (1) A first position controller that calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position controller calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output. A state estimator that derives an estimated angular velocity of the motor by feedback control based on angle information detected from the motor, A first speed controller that calculates an angular velocity command value for the motor based on the speed command value, A second speed controller calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator. A motor control device having (2) A first position controller that calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position controller calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output. A first speed controller that calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimator that derives an estimated angular velocity of the motor by feedback control based on angle information detected from the motor, A second speed controller calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator. It has, A first transfer function of a closed-loop system comprising the first position controller, the second position controller, the first speed controller, the second speed controller, and the state estimator, A second transfer function of a closed-loop system comprising the second position controller, the first speed controller, the second speed controller, and the state estimator, excluding the first position controller, A third transfer function of a closed-loop system comprising the first speed controller, the second speed controller and the state estimator, but excluding the first and second position controllers, A fourth transfer function of a closed-loop system comprising the second speed controller and the state estimator, but not including the first position controller, the second position controller and the first speed controller, Motor control device. (3) A first position control step which calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A first speed control step of calculating an angular velocity command value for the motor based on the speed command value, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. A motor control method having the following characteristics. (4) A first position control step which calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A first speed control step calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. It has, The first transfer function of the closed-loop system is configured by including the first position control step, the second position control step, the first speed control step, the second speed control step, and the state estimation step. The second transfer function of the closed-loop system is configured including the second position control step, the first speed control step, the second speed control step, and the state estimation step, without including the first position control step. A third transfer function of a closed-loop system is configured including the first speed control step, the second speed control step, and the state estimation step, but excluding the first position control step and the second position control step. A fourth transfer function of a closed-loop system is configured including the second speed control step and the state estimation step, but excluding the first position control step, the second position control step and the first speed control step. Motor control method. [Effects of the Invention]

[0008] This invention makes it possible to suppress the effects of errors and noise contained in the signals used for motor control, thereby achieving more precise motor control. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a conceptual diagram showing an example of the configuration of a motor control device, including the motor control system according to the embodiment. [Figure 2] Figure 2 is a graph illustrating the transfer characteristics of one embodiment of the present invention. [Figure 3] Figure 3 is a graph illustrating the transfer characteristics of one embodiment of the present invention. [Figure 4] Figure 4 is a graph illustrating the transfer characteristics of one embodiment of the present invention. [Figure 5] Figure 5 is a graph illustrating the transfer characteristics of one embodiment of the present invention. [Figure 6] Figure 6 is a graph illustrating the transfer characteristics of one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and other documents. The embodiments described below are merely examples for illustrating the present invention and are not intended to be interpreted as limiting the invention. Furthermore, not all configurations described in each embodiment are necessarily essential for solving the problems of the present invention.

[0011] <First Embodiment> The following describes a first embodiment of the present invention. The motor control device according to one embodiment of the present invention may be applied to motors to which the control described later can be applied, such as linear motors and servo motors. Examples of motor systems on which the motor is mounted include, but are not limited to, machine tools, inspection equipment, semiconductor manufacturing equipment, XY stages, and linear drive feed systems using ball screws. In addition, as a detection device for detecting the angle of the motor, resolvers and other angle sensors may be used in addition to encoders.

[0012] [Control System] Figure 1 is a conceptual diagram showing an example configuration of the motor control device 100 according to this embodiment. The motor control device 100 of this embodiment may be a motor control system, or it may be a motor device that includes both the motor control system and the motor. The motor control device 100 according to this embodiment may include a program, a controller, a driver, a motor, and an encoder, which are not shown. The controller may consist of a processing unit such as a CPU (Central Processing Unit) that can read and execute a program, and a storage unit for storing the program.

[0013] The motor control device 100 includes a position control system, a speed control system, a current control system, a motor structure system, a feedback system, and the like. The position control system includes a first position controller 101, a subtractor 103, and a second position controller 105. The position control system is implemented, for example, by a controller (not shown) for controlling a motor (not shown). The speed control system includes a first speed controller 107, a subtractor 109, and a second speed controller 111. The speed control system is implemented, for example, by a controller (not shown) for controlling a motor (not shown), similar to the position control system. The current control system 113 is implemented, for example, by a driver (not shown). The motor structure system includes a torque conversion system 115, a mechanical characteristics system 117, and an integration system 119. The torque conversion system 115, the mechanical characteristics system 117, and the integration system 119 depend on the characteristics of the motor. The feedback system includes an adder 121 and a state estimator 123.

[0014] In the motor control device 100, the position command value θ corresponds to the target position. ref The position command value θ is input to the first position controller 101. ref This is defined by a pre-prepared program and is input at a predetermined timing in conjunction with the execution of the program. The first position controller 101 receives the position command value θ ref The position command value is then calculated using a predetermined calculation formula. The details of this calculation formula will be described later.

[0015] The subtractor 103 subtracts the position information of the angle (angle detection value) θ output from the adder 121 from the position command value calculated by the first position controller 101, thereby calculating the position (angle) deviation e p The result is derived and input to the second position controller 105. In other words, the subtractor 103 receives feedback of the current position information and derives the difference between the position command value and the current position.

[0016] The second position controller 105 controls the position deviation e p For this, the speed command value ω is calculated using a predetermined formula. ref The calculation formula will be described later. The calculated speed command value ω refis input to the first speed controller 107.

[0017] Thus, the speed command value ω corresponding to the target position ref is input to the first speed controller 107. The speed command value ω ref is defined by a program prepared in advance based on the above-described procedure and is input at a predetermined timing as the program is executed. The first speed controller 107 calculates an angular velocity command value using a predetermined calculation formula for the speed command value ω ref . Details of the calculation formula here will be described later.

[0018] The subtractor 109 subtracts the angular velocity estimated value ω^ estimated by a state estimator 123, which will be described later, from the angular velocity command value calculated by the first speed controller 107 to derive a speed deviation e and input it to the second speed controller 111. That is, the subtractor 109 receives feedback of the angular velocity estimated value ω^ at the current time and derives the difference between the angular velocity command value and the current angular velocity.

[0019] The second speed controller 111 calculates a current command value I ref using a predetermined calculation formula for the speed deviation e. Details of the calculation formula here will be described later. The calculated current command value I ref is input to the current control system 113.

[0020] The current control system 113 outputs a q-axis current i ref for driving the motor based on the current command value I q . The current control system 113 performs current control for a power supply (not shown).

[0021] In the torque conversion system 115, the q-axis current i q and the torque constant K TTorque τ is output based on this. In addition, the mechanical characteristics system 117 outputs angular velocity ω based on the mechanical characteristics using torque τ. Furthermore, the angle θ' corresponding to the angular velocity ω is output. This angle θ' from the motor structure system is transmitted to an arbitrary drive unit (not shown), and the drive unit operates. The drive unit may differ depending on the configuration of the system to which the motor control device 100 is applied.

[0022] As feedback from the drive unit, an angular error Δθ is added to the angle θ'. This angular error Δθ is, for example, the detection error of the encoder (not shown). The adder 121 then adds the angle θ' from the motor structure system and the angular error Δθ, and inputs the resulting angle θ to the subtractor 103 and state estimator 123 mentioned above.

[0023] The state estimator 123 derives an angular velocity estimate ω^ based on the angle θ and provides feedback by passing it to the subtractor 109. Details of the derivation of the angular velocity estimate ω^ will be described later.

[0024] As described above, in this embodiment, angular error and noise are considered for each of the three signals. The first is the position command value θ input to the first position controller 101. ref The first is the noise contained in the first speed controller 107, ω. ref The first is noise included in the first signal. The third is the angular error Δθ (linearity error) mixed into the detection signal. In this embodiment, the processing of the first position controller 101, the second position controller 105, the first speed controller 107, the second speed controller 111, and the state estimator 123 is defined to address these errors and noise.

[0025] The transmission characteristics of the motor control according to this embodiment will be explained using Figures 2 to 6. First, the parameters for the transmission characteristics according to this embodiment are defined as follows. Note that each parameter also corresponds to those shown in each block of Figure 1.

[0026] [constant] ω pref : Position control bandwidth [rad / s] ω pdis :Angular error suppression bandwidth on the position control side [rad / s] ω vref Speed ​​control bandwidth [rad / s] ω vdis Angular error suppression bandwidth [rad / s] ω c Current control bandwidth [rad / s] K T Motor torque constant [Nm / A] J: Motor inertia coefficient [kg·m] 2 ] D: Motor viscosity coefficient [Nm / (rad / s)] g1: Gain 1 of the state estimator g2: Gain 2 of the state estimator θ0: Initial value of the angle ω0: Initial value of angular velocity

[0027] [variable] θ ref :Position command [rad / s] e p :Position deviation [rad / s] ω ref :Speed ​​command [rad / s] e: Speed ​​deviation [rad / s] I ref :Current command [A] I q :q-axis current [A] τ: Motor torque [Nm] ω: Angular velocity [rad / s] θ: Angle [rad] Δθ: Angle error [rad] θ^: Angle estimate [rad] ω^: Angular velocity estimate [rad]

[0028] In the conceptual diagram of the motor control device 100 shown in Figure 1, the position command value θ ref By deriving the transfer function from to angular velocity ω and the transfer function from angular error Δθ to angular velocity ω, the following equation can be obtained. Since the term on the right side of equation (2) is sufficiently smaller than the term on the left side, equation (1) can be approximated as in equation (3). Note that ω dis expressed by equation (4), and ζ d This is expressed by equation (5).

[0029]

number

[0030] Equation (4) corresponds to the breakpoint frequency of the BPF (Band Pass Filter). Equation (5) corresponds to the attenuation coefficient of the BPF. Examples of these are shown in Figures 5 and 6.

[0031] In the speed control system shown in Figure 1, the position command value θ ref The first transfer characteristic of the closed-loop system from to angle θ' is a first-order LPF (Low Pass Filter) characteristic (first position controller 101 ~ subtractor 103 ~ second position controller 105 ~ first speed controller 107 ~ subtractor 109 ~ second speed controller 111 ~ current control system 113 ~ torque conversion system 115 ~ mechanical characteristic system 117 ~ integral system 119). In this embodiment, as shown in Figure 2, the position control bandwidth ω pref Set it.

[0032] In Figure 2, the vertical axis represents the angle θ' and the position command value θ. ref The graph shows the gain [dB] for the ratio of , with the horizontal axis representing the angular frequency [rad / s] on a logarithmic scale. Region Ra(0~ω pref ) sets the angle θ' to the position command value θ ref This is the frequency range we want to track. The range Rb(ω pref ~) is the frequency range in which we do not want the angle θ' to follow the position command noise. In other words, ω as the first threshold. pref For the above region Rb, the influence of high-frequency noise contained in region Rb is suppressed by controlling the gain to decrease.

[0033] To achieve the control shown in Figure 2, the first position controller 101 derives the desired position command using the following equation (6). Here, C p1 This is the function function of the first position controller 101.

[0034]

number

[0035] Furthermore, in this embodiment, as shown in Figure 3, the second transfer characteristic of the closed-loop system from the angular error Δθ to the angle θ' becomes a first-order LPF characteristic (adder 121 ~ subtractor 103 ~ second position controller 105 ~ first speed controller 107 ~ subtractor 109 ~ second speed controller 111 ~ current control system 113 ~ torque conversion system 115 ~ mechanical characteristic system 117, integral system 119). In this embodiment, as shown in Figure 3, the position control bandwidth ω pdis Set it.

[0036] In Figure 3, the vertical axis represents the angle θ' and the angular error Δθ, and the position command value θ. ref The graph shows the gain [dB] for the ratio of , with the horizontal axis representing the angular frequency [rad / s] on a logarithmic scale. The region Rc(0~ω pdis ) is the frequency region in which the angle θ' follows the angular error Δθ. pdis ~) is the frequency range in which we do not want the angle θ' to follow the angular error Δθ. In other words, ω as the second threshold. pdis For the above region Rd, the gain is controlled to decrease, thereby suppressing the influence of high-frequency noise contained in region Rd.

[0037] As described above, the position control bandwidth ω on the position control side pref By setting and adjusting this, the position can be tracked according to the position command value in the frequency range below the position control band, and the influence of position command noise is suppressed in the frequency range above the position control band. In addition, the angle error suppression band ω on the position control side pdis By setting and adjusting this, angular errors are suppressed. For example, when using a motor at low to high rotational speeds, ω pdis Set this setting as low as possible to improve this suppression effect.

[0038] To achieve the control shown in Figure 3, the second position controller 105 uses the following equation (7) to determine the target speed command value ω ref We derive the following. Here, Cp2 This is the function function of the second position controller 105.

[0039]

number

[0040] As a result of the above process, the speed command value ω generated from the second position controller 105 is ref This is input to the first speed controller 107.

[0041] Next, the first speed controller 107, the subtractor 109, and the second speed controller 111 will be described. In the speed control system shown in Figure 1, the speed command value ω ref The third transfer characteristic of the closed-loop system from to angular velocity ω is a first-order LPF characteristic (first speed controller 107 ~ subtractor 109 ~ second speed controller 111 ~ current control system 113 ~ torque conversion system 115 ~ mechanical characteristic system 117). In this embodiment, as shown in Figure 4, the speed control bandwidth ω vref Set it.

[0042] In Figure 4, the vertical axis represents angular velocity ω and velocity command value ω. ref The graph shows the gain [dB] for the ratio of , with the horizontal axis representing the angular frequency [rad / s] on a logarithmic scale. The region Re(0~ω vref ) is the angular velocity of the velocity command value ω ref This is the frequency range we want to track. The range Rf(ω vref ~) is the frequency range in which we do not want the angular velocity to follow the velocity command noise. In other words, ω as a third threshold. vref For the above-mentioned Rf region, the gain is controlled to decrease, thereby suppressing the influence of high-frequency noise contained in the Rf region. This third threshold is set based on the speed command value.

[0043] To achieve the control shown in Figure 4, the first speed controller 107 derives the desired angular velocity command using the following equation (8). Here, C v1 This is the function function of the first speed controller 107.

[0044]

number

[0045] On the other hand, in the speed control system shown in Figure 1, the fourth transfer characteristic of the closed-loop system from the angular error Δθ to the angular velocity ω is the first-order LPF characteristic + BPF characteristic (adder 121 ~ state estimator 123 ~ subtractor 109 ~ second speed controller 111 ~ current control system 113 ~ torque conversion system 115 ~ mechanical characteristic system 117). In this embodiment, as shown in Figures 5 and 6, the angular error suppression band ω on the first-order LPF characteristic side is vdis Set the angle error suppression bandwidth ω on the BPF characteristic side. d Set the following. Note that the LPF and BPF characteristics described above are not limited to being realized with commonly known LPFs and BPFs, but can also be realized using components that possess such characteristics.

[0046] In Figures 5 and 6, the vertical axis shows the gain [dB] with respect to the ratio of angular velocity ω to angular error Δθ, and the horizontal axis shows the angular frequency [rad / s] on a logarithmic scale. The angular error suppression bandwidth ω as the fourth threshold shown in Figure 5 d The range up to Rg(0~ω d ) is the region where we want to suppress the low frequency range when the motor is running at a low rotational speed. Also, the angular error suppression band ω as the fifth threshold shown in Figure 6 vdis The above region Rh(ω vdis ~) is the region where we want to suppress the high-frequency range when the motor is running at medium and high rotational speeds. The fourth and fifth thresholds are set to increase as the motor's rotational speed, determined by the speed command value, decreases. In other words, the fourth transfer function is set to have an adjustable fifth threshold that is greater than the fourth threshold for the frequency range of angular velocity. The region greater than the fifth threshold is defined to reduce the gain with respect to the speed command value more than the region between the fourth and fifth thresholds. The gain in the region less than the fourth threshold and the gain in the region between the fourth and fifth thresholds are defined to decrease at the same rate logarithmically, with the fourth threshold as the peak.

[0047] Angular error suppression bandwidth ωvdis By setting and adjusting this, the angular error in the target high-frequency range is suppressed. d By setting and adjusting this, angular errors in the low-frequency range are suppressed. For example, when using a motor at a low rotational speed, the linearity error will be at a low frequency. Corresponding to this, ω d By setting a higher value, it becomes possible to enhance the suppression effect against the desired angular error. Also, when the motor is used at medium or high rotational speeds, the linearity error will be at a high frequency. In response to this, ω vdis By setting this value low, it becomes possible to enhance the suppression effect against the desired angular error.

[0048] To achieve the control shown in Figures 5 and 6, the second speed controller 111 derives the desired current command value using the following equation (9). Here, C v2 This is the function function of the second speed controller 111.

[0049]

number

[0050] [State Estimator] The following describes the design of the state estimator 123 to support the control described above. First, the q-axis current i shown in Figure 1 q The transfer function from to the angle θ (torque conversion system 115 ~ mechanical properties system 117 ~ integral system 119 ~ adder 121) can be defined by the following equation (10).

[0051]

number

[0052] By performing the inverse Laplace transform on equation (10) above and deriving the equation of motion, we obtain the following equation (11).

[0053]

number

[0054] Based on equation (11), we derive the following equation (12) which is the equation of state.

[0055]

number

[0056] Based on equation (12), the state estimator 123 is defined by the following equation (13). Here, "^" indicates the estimated value.

[0057]

number

[0058] Furthermore, based on equations (12) and (13), the derivative of the state estimation error is derived as shown in equation (14) below.

[0059]

number

[0060] Furthermore, based on equation (14), the state estimation error is derived as shown in equation (15) below.

[0061]

number

[0062] Based on the above formulas, the state estimate can be calculated as shown in formula (16) below.

[0063]

number

[0064] Then, from equation (12), the estimated angular velocity ω^ is derived as shown in equation (17).

[0065]

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[0066] In this embodiment, the state estimator 123 is implemented as defined by the following equations (18) and (19) based on the above equation (17).

[0067]

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[0068] Integrating the above equation with respect to time yields the following equation (19).

[0069]

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[0070] Then, by performing various controls in each block shown in Figure 1, the speed command value ω ref This makes it possible to suppress the noise contained in the signal and the angular error Δθ contained in the angle detector.

[0071] More specifically, when the motor is used at low rotational speeds, the linearity error included in Δθ is low frequency. Therefore, when a speed command value corresponding to a low rotational speed is input, ω d and ω vdis By setting this value higher, the suppression effect is improved. Also, when the motor is used at medium or high rotational speeds, the linearity error included in Δθ becomes high frequency. Therefore, when a speed command value corresponding to medium or high rotational speed is input, ω d and ω vdis Lowering this setting improves the suppression effect. Note that the high and low values ​​for parameter adjustment here are relative and not limited to specific values. Therefore, they may be determined as appropriate depending on the motor configuration, etc.

[0072] Furthermore, ω is an adjustable parameter. vref , ω d , ω vdisThis can be switched in stages in response to the motor speed, or it can be adjusted seamlessly. For example, as the rotation speed decreases, ω can be gradually switched. d You may adjust it to increase ω. Also, as the rotational speed increases, gradually d and ω vdis You may adjust it so that it becomes lower.

[0073] As described above, in the motor control according to this embodiment, the error included in the encoder's detected value is considered and fed back into the position command, and the encoder's angle information is acquired by the state estimator. Furthermore, since feedforward control results in a unidirectional signal flow, if parameter correction along the way is insufficient, it becomes difficult to issue a highly accurate speed command. Therefore, the motor control according to this embodiment uses a configuration based on feedback control. By performing feedback control of angle information in the state estimator, the output accuracy of the state estimator is improved. As a result, it becomes possible to track the speed command with high accuracy.

[0074] As described above, this embodiment, by combining a state estimator for estimating angular velocity with a position and speed controller, makes it possible to suppress the effects of noise and errors contained in the signals used for motor control, thereby achieving more accurate motor control. In particular, by seamlessly adjusting the parameters according to the motor's angular velocity, it is possible to suppress angular errors over a wide range of rotational speeds. Furthermore, it becomes possible to suppress sounds and vibrations caused by noise and errors.

[0075] <Other Embodiments> Furthermore, the present invention can also be realized by supplying a program or application for realizing the functions of one or more embodiments described above to a system or device using a network or storage medium, and having one or more processors in the computer of that system or device read and execute the program.

[0076] Thus, the present invention is not limited to the embodiments described above. It is also intended and within the scope of protection to be provided for the combination of each configuration of the embodiments, as well as for modifications and applications by those skilled in the art based on the description in the specification and well-known technology.

[0077] As described above, the following matters are disclosed in this specification: (1) Input position command value (for example, θ ref A first position controller (e.g., 101) calculates an angle command value for the angle at which the motor rotates based on the following: A second position controller (e.g., 105) calculates a speed command value from the angle deviation relative to the motor using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output, A state estimator (e.g., 123) that derives an estimated angular velocity (e.g., ω^) of the motor by feedback control based on angle information (e.g., θ) detected from the motor, The aforementioned speed command value (for example, ω ref A first speed controller (e.g., 107) calculates an angular velocity command value for the motor based on the above, Using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator, the current command value (for example, I) is calculated from the angular velocity deviation for the motor. ref A second speed controller (e.g., 111) calculates the following: A motor control device having This motor control device suppresses the effects of angular errors and noise in the signals used for motor control, making it possible to track the rotation speed exactly as commanded.

[0078] (2) Input position command value (for example, θ ref A first position controller (e.g., 101) calculates an angle command value for the angle at which the motor rotates based on the following: A second position controller (e.g., 105) calculates a speed command value from the angle deviation relative to the motor using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output, A first speed controller that calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimator (e.g., 123) that derives an estimated angular velocity (e.g., ω^) of the motor by feedback control based on angle information (e.g., θ) detected from the motor, Using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator, the current command value (for example, I) is calculated from the angular velocity deviation for the motor. ref A second speed controller that calculates ) and It has, A first transfer function of a closed-loop system comprising the first position controller, the second position controller, the first speed controller, the second speed controller, and the state estimator, A second transfer function of a closed-loop system comprising the second position controller, the first speed controller, the second speed controller, and the state estimator, excluding the first position controller, A third transfer function of a closed-loop system comprising the first speed controller, the second speed controller and the state estimator, but excluding the first and second position controllers, A fourth transfer function of a closed-loop system comprising the second speed controller and the state estimator, but not including the first position controller, the second position controller and the first speed controller, Motor control device. This motor control device makes it possible to suppress the effects of angular errors and noise contained in the signals used for motor control, thereby achieving more precise motor control.

[0079] (3) The first transfer function is set to a first threshold (e.g., ω) that is adjustable with respect to the frequency domain of the angle. pref For regions larger than ), the gain with respect to the position command value is reduced. The second transfer function reduces the gain with respect to the angle error for a region that is set to be adjustable with respect to the frequency region of the angle and is larger than a second threshold value (for example, ω pdis ). The third transfer function reduces the gain with respect to the speed command value for a region that is set to be adjustable with respect to the frequency region of the angular velocity and is larger than a third threshold value (for example, ω vref ) (for example, R b ). The fourth transfer function reduces the gain with respect to the input value based on the angle error, with a fourth threshold value (for example, ω d ) that is set to be adjustable with respect to the frequency region of the angular velocity as a peak. The motor control device according to (2). According to this motor control device, it is possible to suppress the influence of angle errors and noise included in the signals used for motor control, and to achieve more accurate motor control.

[0080] (4) The fourth transfer function is in a region that is larger than the fourth threshold value and also larger than a fifth threshold value (for example, ω vdis ) that is set to be adjustable with respect to the frequency region of the angular velocity. In this region (for example, R d ), the gain with respect to the speed command value is reduced more than in the region between the fourth threshold value and the fifth threshold value. The motor control device according to (3). According to this motor control device, it is possible to suppress angle errors and noise in a higher frequency region. As a result, it is possible to suppress sounds and vibrations caused by angle errors and noise.

[0081] (5) The motor control device according to (4), wherein the gain in the region smaller than the fourth threshold value and the gain in the region between the fourth threshold value and the fifth threshold value decrease at the same logarithmic ratio with the fourth threshold value as a peak. According to this motor control device, it is possible to achieve an equivalent suppression effect before and after the target frequency.

[0082] (6) The motor control device according to (3), wherein the third threshold is set based on the speed command value. This motor control device allows you to define the frequency range in which you want the angular velocity to follow the speed command value, and the frequency range in which you do not want the angular velocity to follow the speed command value. This makes it possible to suppress the effects of desired high-frequency noise.

[0083] (7) The motor control device according to (3), wherein the fourth threshold increases as the rotational speed of the motor according to the speed command value decreases. This motor control device allows for the suppression of low-frequency linearity errors when the motor is used at low rotational speeds, and to suppress high-frequency linearity errors when the motor is used at medium or high rotational speeds. Therefore, it is possible to suppress the effects of angular errors and noise according to the rotational speed.

[0084] (8) The motor control device according to (4), wherein the fifth threshold increases as the rotational speed of the motor according to the speed command value decreases. This motor control device makes it possible to control the motor in a way that suppresses linearity errors at higher frequencies.

[0085] (9) A first position control step which calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A first speed control step of calculating an angular velocity command value for the motor based on the speed command value, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. A motor control method having the following characteristics. This motor control device suppresses the effects of angular errors and noise in the signals used for motor control, making it possible to track the rotational speed exactly as commanded.

[0086] (10) A first position control step which calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A first speed control step calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. It has, The first transfer function of the closed-loop system is configured by including the first position control step, the second position control step, the first speed control step, the second speed control step, and the state estimation step. The second transfer function of the closed-loop system is configured including the second position control step, the first speed control step, the second speed control step, and the state estimation step, without including the first position control step. A third transfer function of a closed-loop system is configured including the first speed control step, the second speed control step, and the state estimation step, but excluding the first position control step and the second position control step. A fourth transfer function of a closed-loop system is configured including the second speed control step and the state estimation step, but excluding the first position control step, the second position control step and the first speed control step. Motor control method. This motor control method suppresses the effects of angular errors and noise contained in the signals used for motor control, making it possible to achieve more precise motor control.

[0087] (11) The first transfer function is defined such that an adjustable first threshold is set for the frequency domain of the angle, and the gain with respect to the position command value is reduced in the region greater than the first threshold, The second transfer function is defined such that an adjustable second threshold is set for the frequency domain of the angle, and the gain for the angular error is reduced in the region greater than the second threshold. The third transfer function is defined such that, with respect to the frequency domain of angular velocity, an adjustable third threshold is set, and the gain with respect to the velocity command value is reduced in the region greater than the first threshold. The motor control method according to (10), wherein the fourth transfer function is defined such that an adjustable fourth threshold is set for the frequency domain of angular velocity, and the gain with respect to the input value based on the angular error decreases with respect to the second threshold as the peak. This motor control method suppresses the effects of angular errors and noise contained in the signals used for motor control, making it possible to achieve more precise motor control. [Explanation of Symbols]

[0088] 100...Motor control device 101...First position controller 103... Subtractor 105...Second position controller 107...First speed controller 109... Subtractor 111...Second speed controller 113...Current control system 115... Torque conversion system 117... Mechanical properties 119...Integral system 121... Adder 123... State Estimator

Claims

1. A first position controller calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position controller calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output. A state estimator that derives an estimated angular velocity of the motor by feedback control based on angle information detected from the motor, A first speed controller that calculates an angular velocity command value for the motor based on the speed command value, A second speed controller calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator, A motor control device having

2. A first position controller calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position controller calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated by the first position controller and the angle detection value including the angle error in the motor output. A first speed controller that calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimator that derives an estimated angular velocity of the motor by feedback control based on angle information detected from the motor, A second speed controller calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated by the first speed controller and the angular velocity estimate value estimated by the state estimator, It has, A first transfer function of a closed-loop system comprising the first position controller, the second position controller, the first speed controller, the second speed controller, and the state estimator, A second transfer function of a closed-loop system comprising the second position controller, the first speed controller, the second speed controller, and the state estimator, excluding the first position controller, A third transfer function of a closed-loop system comprising the first speed controller, the second speed controller and the state estimator, but excluding the first and second position controllers, A fourth transfer function of a closed-loop system comprising the second speed controller and the state estimator, but not including the first position controller, the second position controller and the first speed controller, Motor control device.

3. The first transfer function reduces the gain with respect to the position command value in the region of the angle frequency domain that is greater than a first threshold that is set to be adjustable. The second transfer function reduces the gain with respect to the angular error in the region of the angle that is greater than a second threshold that is set to be adjustable with respect to the frequency domain of the angle. The third transfer function reduces the gain with respect to the speed command value in the region of the angular velocity that is greater than a third threshold that is set to be adjustable with respect to the frequency domain. The fourth transfer function reduces the gain with respect to the input value based on the angular error, with respect to the frequency domain of the angular velocity, peaking at a fourth threshold that is adjustable. The motor control device according to claim 2.

4. The fourth transfer function reduces the gain to the speed command value in the region of the angular velocity frequency domain that is greater than the fourth threshold and greater than a fifth threshold that is set to be adjustable, compared to the region between the fourth threshold and the fifth threshold. The motor control device according to claim 3.

5. The gain in the region smaller than the fourth threshold and the gain in the region between the fourth threshold and the fifth threshold reduce the value logarithmically at the same rate, with the fourth threshold as the peak. The motor control device according to claim 4.

6. The third threshold is set based on the speed command value. The motor control device according to claim 3.

7. The fourth threshold increases as the rotational speed of the motor, determined by the speed command value, decreases. The motor control device according to claim 3.

8. The fifth threshold increases as the rotational speed of the motor, determined by the speed command value, decreases. The motor control device according to claim 4.

9. A first position control step calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A first speed control step of calculating an angular velocity command value for the motor based on the speed command value, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. A motor control method having the following characteristics.

10. A first position control step calculates an angle command value for the angle at which the motor rotates based on the input position command value, A second position control step calculates a speed command value from the angle deviation relative to the motor, using the angle command value calculated in the first position control step and the angle detection value including the angle error in the motor output. A first speed control step calculates an angular velocity command value for the motor based on the aforementioned speed command value, A state estimation step in which an estimated angular velocity of the motor is derived by feedback control based on angle information detected from the motor, A second speed control step calculates a current command value from the angular velocity deviation for the motor using the angular velocity command value calculated in the first speed control step and the angular velocity estimate value estimated in the state estimation step. It has, The first transfer function of the closed-loop system is configured by including the first position control step, the second position control step, the first speed control step, the second speed control step, and the state estimation step. The second transfer function of the closed-loop system is configured by including the second position control step, the first speed control step, the second speed control step, and the state estimation step, without including the first position control step. A third transfer function of a closed-loop system is configured including the first speed control step, the second speed control step, and the state estimation step, but excluding the first and second position control steps. A fourth transfer function of a closed-loop system is configured including the second speed control step and the state estimation step, but excluding the first position control step, the second position control step and the first speed control step. Motor control method.

11. The first transfer function is defined such that an adjustable first threshold is set for the frequency domain of the angle, and the gain with respect to the position command value is reduced in the region greater than the first threshold. The second transfer function is defined such that an adjustable second threshold is set for the frequency domain of the angle, and the gain for the angular error is reduced in the region greater than the second threshold. The third transfer function is defined such that an adjustable third threshold is set for the frequency domain of angular velocity, and the gain with respect to the velocity command value is reduced in the region greater than the first threshold. The fourth transfer function is defined such that, with respect to the frequency domain of angular velocity, an adjustable fourth threshold is set, and the gain with respect to the input value based on the angular error decreases, with the second threshold being the peak. The motor control method according to claim 10.

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