Motor control device

Abstract

The present invention provides an electric motor control device capable of receiving a speed command from a superior system control device having a position controller, comprising: a position command estimator that calculates an estimated value of a position command based on a speed command and a motor shaft position response; and a speed command generator that generates an actual speed command such that an end portion of a machine connected to the electric motor does not vibrate based on the estimated value, the actual speed command being output from the speed command generator to a speed controller.

Description

Technical Field

[0001] This invention relates to a control device for an electric motor. Background Technology

[0002] In a semi-enclosed electric motor control system designed to control the machinery of the controlled object, there are cases where the rigidity of the machinery mounted on the motor is low. Generally, the ends of the machinery vibrate due to the resonance and anti-resonance characteristics of the machinery, and the required response characteristics cannot be achieved.

[0003] In the field of computer vision (FA), improving the response of the control system is necessary to improve cycle time.

[0004] However, in a semi-enclosed electric motor control system, where the mechanical rigidity is low, it is difficult to improve the response of the control system due to reasons such as the mechanical ends vibrating at low frequencies of several Hz to 100 Hz and the time-consuming positioning.

[0005] In such cases, vibration reduction control is generally used. When the motor control system is a position control system, vibration reduction control is usually achieved through the processing of position commands.

[0006] Specifically, the position command activates the low-pass filter and notch filter to remove the frequency components that excite the vibration of the machine's end from the position command, thereby achieving vibration reduction at the machine's end.

[0007] Patent Document 1 describes how two vibration damping filters can be used to switch between position commands, enabling vibration damping at the ends of the machine even when the resonant / anti-resonant characteristics of the machine change. A notch filter is cited as an example of a vibration damping filter.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2005-168225 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In semi-enclosed motor control systems in the field of computer engineering (FA), such as Figure 15 As shown, there are cases where, due to industrial reasons such as machine replacement, the upper-level system control device that generates position commands has a position controller and a speed control system with a servo motor control device as a small loop.

[0013] Furthermore, there are situations where vibration reduction control cannot be achieved using a position controller due to maintenance requirements and the specifications of each device, and vibration reduction control must be achieved within the servo motor control device that is responsible for the speed control system, which acts as a small loop.

[0014] In Patent Document 1, the vibration reduction filter 3, filter switching unit 9, and command direction detection unit 4 involved in vibration reduction control are... Figure 15 The structure in Patent Document 1 implements vibration reduction control within the upper-level system control device. Therefore, vibration reduction control is not implemented within the servo motor control device responsible for the speed control system in Patent Document 1.

[0015] The purpose of this invention is to provide a motor control device that does not process position commands for the purpose of vibration reduction at the end of the machine in the upper-level system control device, but instead realizes vibration reduction control in the motor servo control device responsible for the speed control system.

[0016] Technical solutions for solving the problem

[0017] As a preferred example of the present invention, a motor control device capable of receiving speed commands from an upper-level system control device having a position controller includes: a position command estimator that calculates a calculated value of the position command based on the speed command and the motor shaft position response; and a speed command generator that generates an actual speed command based on the calculated value such that the end of the machinery connected to the motor does not vibrate, and outputs the actual speed command to a speed controller from the speed command generator.

[0018] Invention Effects

[0019] According to the present invention, the processing of position commands for the purpose of vibration reduction at the end of the machine can be carried out without being performed in the upper-level system control device, but vibration reduction control can be achieved in the motor servo control device responsible for the speed control system. Attached Figure Description

[0020] Figure 1 This is a diagram showing the first basic structure of Embodiment 1.

[0021] Figure 2 This is a diagram showing the second basic structure of Embodiment 1.

[0022] Figure 3 It means Figure 1 A diagram showing the specific structure.

[0023] Figure 4 This is a graph representing the frequency characteristics of a vibration-excited component extractor.

[0024] Figure 5 It means and Figure 2 The diagram shows the structure of the corresponding FF-type vibration reduction control system.

[0025] Figure 6 It means including with Figure 2 The diagram shows the structure of the corresponding FF controller.

[0026] Figure 7 It means Figure 6 A diagram showing the specific structure of the FF controller.

[0027] Figure 8 This is a diagram showing the structure under FB-type vibration control.

[0028] Figure 9 It means Figure 8 A diagram showing the specific structure of the parallel vibration damping controller.

[0029] Figure 10 This is a block diagram for cases with specified filters.

[0030] Figure 11 This is a structural diagram of a parallel vibration reduction control system that processes the shaft position response of a motor.

[0031] Figure 12 It means Figure 5 The diagram shows the effect of vibration reduction control in the structure.

[0032] Figure 13 This is a diagram representing a typical AC servo motor control system.

[0033] Figure 14 This is a diagram showing an AC servo motor control system with a vibration damping controller within the speed control system.

[0034] Figure 15 It is a diagram showing the structure consisting of a higher-level system control device and a servo motor control device.

[0035] Figure 16 This is a diagram showing the vibration reduction control within the speed control system of the comparative example. Detailed Implementation

[0036] The device structure of the upper-level system control device for generating position commands to be implemented in this invention, which has a position controller and a servo motor control device responsible for the speed control system of a small loop, will first be described using a comparative example.

[0037] Figure 16 This is a diagram representing comparative examples. For example... Figure 16 As shown, by inserting a notch filter 1601 into the speed control system, the frequency component of the vibration that excites the mechanical end can be removed from the speed command. Furthermore, the notch frequency 1602 of the notch filter 1601 is set to match the frequency of the mechanical end vibration.

[0038] In the comparative example, the phase delay characteristics around the notch frequency of the notch filter 1601 reduce the stability margin of the position control system, and the mechanical response becomes oscillatory at frequencies other than the mechanical resonant / anti-resonant characteristics. The lower the frequency domain of the mechanical resonant / anti-resonant characteristics and the higher the gain of the position controller is to improve the cycle time, the more unavoidable this phenomenon becomes.

[0039] That is, in a semi-enclosed motor control system, when vibration reduction control is performed in the servo motor control device responsible for the speed control system, in the comparative example, there is a problem that it is difficult to reduce the vibration of the mechanical end in the low frequency range of several Hz to 100 Hz.

[0040] Hereinafter, embodiments will be described with reference to the accompanying drawings. In addition, in each drawing, components with common functions will be given the same reference numerals, and their descriptions will be omitted. Furthermore, "feedback" will sometimes be abbreviated as "FB" and "feedforward" as "FF".

[0041] Example 1

[0042] Figure 1 and Figure 2 This is a diagram showing a cascade feedback motor control system with a semi-enclosed structure, including the vibration damping controller 4 and the vibration damping controller 21 within the speed control system of Embodiment 1.

[0043] Figure 1 and Figure 2 The servo motor control device 3 shown is installed in the position control system to receive speed commands from the upper-level system control device 2 and output motor shaft position response 15 to the upper-level system control device 2. The upper-level system control device 2, installed in the position control system, has a position controller 7 that generates position commands and, based on the position commands and the motor shaft position response 15 received from the servo motor control device 3, uses the position controller 7 to generate speed commands. The position controller inputs the position command 13 and the motor shaft position response 15 and outputs a position operation quantity (speed command 14).

[0044] Figure 1The servo motor control unit 3 is responsible for the speed control system of the motor. It has a speed controller 8 and a vibration damping controller 4 within the speed control system. The speed controller 4 has a position command estimator 5 that calculates a position command estimate 34 based on the speed command 14 and the motor shaft position response 15, and a speed command generator 6 that generates an actual speed command 16 based on the position command estimate 34 to prevent vibration of the end 17 of the machine. The actual speed command 16 is used as a command for the speed controller 8. The speed controller 8 inputs the actual speed command 16 and the motor shaft speed response 15 and outputs the speed operation quantity as a current command to the current control system 9.

[0045] In addition, for ease of explanation, the output of the position / speed calculator 10 may sometimes represent the motor shaft position response 15, and sometimes the motor shaft speed response 15.

[0046] Figure 2 The servo motor control device 3 is responsible for the speed control system of the motor. It has a speed controller 8 and a vibration damping controller 21 within the speed control system. The servo motor control device 3 has a position command calculator 5 that calculates a position command value 34 based on the speed command 14 and the motor shaft position response 15, a parallel vibration damping controller 23 that extracts the frequency components of the vibration of the end 17 of the excitation machinery included in the speed command based on the position command value 34 and outputs the extracted frequency components, and an adder / subtractor 24. The adder / subtractor 24 subtracts the output of the parallel vibration damping controller 23 from the speed command 14, removes the frequency components of the vibration of the end 17 of the excitation machinery from the speed command 14, and uses the output of the adder / subtractor 24 as the actual speed command 27 as the output of the vibration damping controller 21 within the speed control system. The actual speed command 27 is used as the command of the speed controller 8.

[0047] When the rigidity of the machinery mounted on the motor shaft is low, for example, when the control gains of the position controller 7 and speed controller 8 are increased to shorten the positioning time, the end of the machinery connected to the motor (hereinafter referred to as the mechanical end) 17 vibrates at a low frequency of several Hz to 100 Hz, which may result in longer positioning time and difficulty in improving response. In this case, vibration reduction control can generally suppress the vibration of the mechanical end 17, thereby shortening the positioning time.

[0048] This implementation example Figure 1 and Figure 2 As shown, the motor control system is envisioned as consisting of a higher-level system control device 2 and a servo motor control device 3.

[0049] The upper-level system control device 2 generates a position command 13, including a position controller 7, receives a motor shaft position response (a response indicating the position of the motor rotor) 15 from the servo motor control device 3, and generates a speed command 14 based on the position command 13 and the motor shaft position response 15 using the position controller 7, and outputs it to the servo motor control device 3.

[0050] Alternatively, position command 13 can also be given from outside the upper-level system control device 2 by other upper-level devices, etc.

[0051] The servo motor control device 3 includes a speed controller 8, a current control system 9, a position / speed calculator 10, and a vibration damping controller 4 (or 21) within the speed control system. It receives speed commands 14 from the upper-level system control device 2, performs speed control on the motor, and calculates the position and speed of the motor shaft using the position / speed calculator 10 based on the measurement signals from sensors (e.g., rotary encoders) installed in the motor that can determine the position / speed. It outputs the motor shaft position response 15 and the motor shaft speed response 15 to the upper-level system control device 2.

[0052] The servo motor control unit 3 has a CPU (Central Processing Unit), which is not shown in the diagram. Within the speed control system, which includes various processing units such as the position command calculator 5, speed command generator 6, and parallel vibration damping controller, the vibration damping controller 21, speed controller 8, and position / speed calculator 10 are processed by the CPU, which reads and executes the program. Each processing unit can be constructed entirely or partially using hardware such as ASIC (Application Specific Integrated Circuit) and FPGA (Field Programmable Gate Array). Furthermore, the upper-level system control unit 2 has a CPU that executes the program corresponding to the position controller 7.

[0053] Position command 13 activates a low-pass filter or notch filter to remove frequency components of the vibration of the excitation mechanical end 17 from the position command 13, thereby implementing vibration reduction control.

[0054] However, there are cases where vibration reduction control cannot be achieved using the position controller 7 due to reasons such as machine replacement and maintenance, and the specifications of each device. In such cases, vibration reduction control must be achieved within the servo motor control device 3, which is responsible for the speed control system as a small loop.

[0055] In Example 1, the problem is to implement vibration reduction control within the servo motor control device 3, excluding vibration reduction control from the position controller 7 of the upper-level system control device 2. In this example, the vibration reduction controller 4 (or 21) within the speed control system is used to solve this problem.

[0056] Feedforward vibration control is formed by removing the frequency component of the vibration at the excitation mechanical end from the position command 13.

[0057] In principle, the following steps are required to implement this control within the speed control system.

[0058] S1: Instruction to know / calculate position.

[0059] S2: Extract the frequency components that excite the mechanical end vibration from the known / calculated position command.

[0060] S3: Generate a speed command that does not include the frequency components extracted in S2, and use it as the speed command for the speed controller.

[0061] Figure 3 It means and Figure 1 A diagram showing an example of the structure of the vibration damping controller 4 within the corresponding speed control system.

[0062] The vibration damping controller 31 in the speed control system consists of a vibration excitation component extractor 33 that extracts the frequency components of the vibration at the excitation mechanical end, a position command calculator 5 that calculates the position command 13, an actual position controller 32, and an adder / subtractor 35.

[0063] In addition, for the sake of simplicity, it is assumed that the position instruction calculator 5 can correctly calculate the position instruction 13.

[0064] Based on the position command 36 obtained by removing the output of the vibration excitation component extractor 33 (implementation S2) from the position command calculation value 34 (implementation S1) calculated by the position command estimator 5 using the adder / subtractor 35, which does not include the frequency component of the excitation mechanical end vibration, and the motor shaft position response 15, the actual position controller 32 generates the speed command 37 (implementation S3).

[0065] thus, Figure 3 The vibration damping controller 31 in the speed control system shown can implement the above S1 to S3 and can reduce vibration at the mechanical end.

[0066] In addition, the vibration excitation component extractor 33 is a filter that can extract the frequency components of the excitation mechanical end vibration from the position command calculation value 34 without phase delay. As an example, the following formula can be given as equivalent to a line enhancer (LE).

[0067] [Mathematical Expression 1]

[0068]

[0069] Where W is the extraction width, L is the parameter responsible for extracting the power level, and ωn is the extracted frequency [rad / s]. Figure 4 The figure shows the frequency characteristics of equation (1) when W = 1, L = 0.1, and ωn = 2π × 10. The characteristic is that the amplitude reaches its peak at frequency ωn and the phase delay is 0.

[0070] In the vibration damping controller 31 within the speed control system, the actual position controller 32 performs position control, while the position controller 7 included in the upper-level system control device 2 is not inherently responsible for position control. Therefore, the control gain of the position controller 7 does not need to be consistent with the control gain of the actual position controller 32.

[0071] Furthermore, the actual position controller 32 can also be a controller with a different structure than the position controller 7. For example, there may be a case where the position controller 7 is a PID controller and the actual position controller 32 is a P controller.

[0072] The vibration damping controller 31 in the speed control system has the design freedom of the actual position controller 32. On the other hand, an actual position controller 32 is required in addition to the position controller 7. This point should be noted.

[0073] Figure 5 It means and Figure 2 The diagram shows the structure of the corresponding FF-type vibration reduction control system.

[0074] Figure 5 The vibration damping controller 51 in the speed control system consists of a vibration excitation component extractor 52 that extracts the frequency components of the vibration at the excitation mechanical end, a position command calculator 5 that calculates the position command 13, a unit converter 53, and an adder / subtractor 54.

[0075] In addition, for the sake of simplicity, it is assumed that the position instruction calculator 5 can correctly calculate the position instruction 13.

[0076] The vibration damping controller 51 in the speed control system extracts the frequency components of the vibration of the excitation mechanical end without phase delay (corresponding to S2) based on the position command calculation value 55 calculated by the position command estimator 55. The unit converter 53 converts the signal obtained from the vibration excitation component extractor 52 into the unit of speed. The signal obtained by removing the output 56 of the unit converter 53 from the speed command 14 by the adder and subtractor 54 is used as the speed command of the speed controller 8, and as the actual speed command 57 (corresponding to S3).

[0077] thus, Figure 5The vibration damping controller 51 in the speed control system shown can implement the above S1 to S3 and can reduce vibration at the mechanical end.

[0078] An example of a vibration excitation component extractor 52 is LE as shown in equation (1). An example of a unit converter 53 is a position controller 7 included in the upper-level system control device 2.

[0079] The position controller 7 is responsible for generating speed commands based on the position command 13 and the deviation between the position command 13 and the motor shaft position response 15. Therefore, within the vibration damping controller 51 of the speed control system, the position controller 7 can function as a unit converter 53.

[0080] An example of position instruction calculator 5 is the following formula.

[0081] [Mathematical Expression 2]

[0082] r e =F p ·s r +y p (2)

[0083] Where re represents the calculated position command value 55, sr represents the speed command 14, and yp represents the motor shaft position response 15. Fp is a calculation filter consistent with the inverse characteristic of position controller 7. For example, if position controller 7 is a P controller, then Fp is the inverse characteristic of the P controller, that is, the reciprocal of the P gain.

[0084] Figure 5 The vibration damping controller 51 in the speed control system shown is not an FB-type vibration damping control based on the position response of the motor end, but an FF-type vibration damping control that processes the command FF. It plays the role of applying a notch filter to the position command 13 to perform vibration damping control.

[0085] Therefore, similar to the case of vibration reduction control using a notch filter, the actual speed command 57 tends to have a rise delay compared to the speed command 14, and the motor shaft position response 15 is further delayed relative to the actual speed command 57. Figure 6 The diagram shows a structure with a scheme to improve such response delay by means other than increasing the control gain of the position controller 7.

[0086] Figure 6 It means including with Figure 2 The diagram shows an example of the structure of the FF controller corresponding to the basic structure shown.

[0087] Assumption Figure 6 The vibration excitation component extractor 52 and unit converter 53 described herein are... Figure 5 The functions described in the text are the same. Figure 6 Structure and Figure 5 In comparison, the parallel vibration damping controller 23 is supplemented with adder / subtractor 64, adder / subtractor 65 and FF controller 62.

[0088] In the parallel vibration damping controller 23, the vibration excitation component extractor 52 extracts the frequency component of the excitation mechanical end vibration from the position command calculation value 55, and outputs the extracted frequency component of the excitation mechanical end vibration to the adder / subtractor 65. The adder / subtractor 65 subtracts the output of the vibration excitation component extractor 52 from the position command calculation value 55. For the signal 67 from the adder / subtractor 65, it is processed by the differential element controller 62 with scalar adjustment gain, and the adder / subtractor 64 subtracts the output 68 of the FF controller 62 from the output of the unit converter 53, thereby calculating the output signal 63. The adder / subtractor 54 subtracts the output signal 63 from the speed command 14. The output signal 66 of the adder / subtractor 54 is the output of the vibration damping controller 61 in the speed control system, and is output to the speed controller 8 as the speed command of the speed controller 8.

[0089] In the position control system of motor control, the controlled object is ideally an integrator. Therefore, the FF controller 62 can basically use a derivative element with a scalar adjustable gain.

[0090] Figure 6 In the structure, signal 67 represents the position command calculated from position command value 55 after removing the frequency component of the vibration of the excitation mechanical end. By applying FF controller 62 to it, the effect of advancing the response characteristics in FF control can be obtained simultaneously with the vibration reduction effect.

[0091] Furthermore, the structure of the FF controller 62 has degrees of freedom; for example, the FF controller 62 can be configured as follows: Figure 7 The example shown is a typical model-matching two-degree-of-freedom control structure.

[0092] in addition, Figure 7 In the typical model-matched two-degree-of-freedom control shown, the FF controller 73 is configured such that the response 76 of the controlled object becomes the standard response 75 obtained by processing the instruction 74 using the standard model 71. The FB controller 72 is configured to suppress the deviation between the standard response 75 and the response 76 of the controlled object. In this case, the FF controller 73 can be basically configured according to the inverse characteristics of the transfer function of the control object multiplied by the standard model 71.

[0093] according to Figure 6 The structure, in addition to increasing the control gain of the position controller 7, can improve the responsiveness by using the FF controller 62 set in the parallel vibration damping controller 23.

[0094] in addition, Figure 5 and Figure 6In the motor control system, there exists an FB loop that passes through the position command calculator 5 of the vibration damping controller 21 (or 51, 61) within the speed control system. However, this loop does not suppress external disturbances applied to the controlled object, nor does it suppress the vibration of the mechanical end caused by external disturbances applied to the controlled object. This is important to note. This is because the parallel vibration damping controller 23 performs the function of FF-type vibration damping control.

[0095] Furthermore, even when external disturbances are applied to the controlled object and the influence of external disturbances is superimposed on the motor shaft position response 15, the position command calculator 5 can still function as long as it does not... Figure 5 and Figure 6 When the processing system on the left side of the position command estimator 5 applies external interference, it can calculate the position command 13 regardless of whether there is an external interference effect superimposed in the motor shaft position response 15.

[0096] In actual use, the communication delay between the upper-level system control device 2 and the servo motor control device 3, as well as the quantization errors in each process, are assumed to be external interference factors. However, as long as they are sufficiently small, they will not cause problems.

[0097] As mentioned above, such as Figure 5 , Figure 6 The FF-type vibration control shown cannot suppress the vibration of the mechanical end caused by external interference.

[0098] Figure 8 This diagram illustrates a structure that can suppress mechanical end vibrations caused by external disturbances by performing FB-type vibration damping control. Specifically, the parallel vibration damping controller 82 learns of the influence of external disturbances via the motor shaft position response 15 and performs FB-type vibration damping control to suppress mechanical end vibrations caused by external disturbances.

[0099] Figure 8 The parallel vibration damping controller 82 shown calculates the inverse component of the vibration component at the end of the machine 17 based on the output of the position command calculator 5 and the motor shaft position response 15, and uses the inverse component as the output of the parallel vibration damping controller 82. The adder / subtractor 83 of the vibration damping controller 81 in the speed control system subtracts the inverse component from the speed command 14, and outputs the subtraction result as the actual speed command 84 to the speed controller 8.

[0100] Figure 9 It means Figure 8 A diagram showing an example of a parallel vibration damping controller 82. Figure 9 Is for Figure 5 The parallel vibration damping controller 23 shown has an additional structure including a standard response model 91, a mechanical end vibration characteristic model 92, an adder / subtractor 64, an adder / subtractor 65 and an adder / subtractor 98, and a unit converter 94.

[0101] like Figure 9 As shown, the parallel vibration damping controller 82 has a standard response model 91 that specifies the response of the position control system to the required response without vibration relative to the position command, a mechanical end vibration characteristic model 92 representing the transmission characteristics from the motor shaft to the mechanical end, a third adder / subtractor 98, and a unit converter 94 that converts the units of the input signal to the velocity dimension. The third adder / subtractor 98 removes the motor shaft position response 15 from the signal obtained by processing the output of the position command estimator 5 using the standard response model 91. The processed signal is processed by the unit converter 94 to process the output signal of the third adder / subtractor 98 as the inverted component of the vibration component of the mechanical end. The signal obtained by the sixth adder / subtractor (64, 54) is removed from the speed command to extract the frequency component of the vibration of the end of the excitation machine. The inverted component is removed from the speed command 14 by the sixth adder / subtractor (64, 54). The output of the sixth adder / subtractor (64, 54) is used as the actual speed command 97, which is used as the output of the vibration damping controller 81 in the speed control system.

[0102] FB-type vibration reduction control can generally be achieved by subtracting the inverse phase of the vibration at the mechanical end from the speed command 14. The standard response model 91 and the mechanical end vibration characteristic model 92 are used to calculate the inverse phase of the vibration at the mechanical end.

[0103] The standard response model 91 is a model that specifies the response of a position control system to the required response without vibration relative to a position command, for example, the following formula.

[0104] [Mathematical Expression 3]

[0105] Standard response model

[0106] Where ωf is the response frequency of the position control system [rad / s].

[0107] On the other hand, the mechanical end vibration characteristic 92 represents the transmission characteristic from the motor shaft to the mechanical end. Therefore, when the controlled object is regarded as a two-inertial system, the following formula is given.

[0108] [Mathematical Expression 4]

[0109] Mechanical end vibration characteristic model

[0110] Where ωa and ζa are the anti-resonance frequency [rad / s] and anti-resonance attenuation coefficient of the two-inertial system, respectively.

[0111] like Figure 9As shown, the mechanical end response can be calculated using the mechanical end vibration characteristic model 92, and the calculated value of the mechanical end response can be obtained as the calculated mechanical end signal 99. On the other hand, the response of an ideal position control system without mechanical end vibration can be calculated using the standard response model 91 as the ideal response signal 93.

[0112] By subtracting the calculated mechanical end signal 99 from the ideal response signal 93 using adder / subtractor 98, the inverse component of the mechanical end vibration superimposed on the mechanical end response can be extracted. To this end, unit converter 94 is activated to convert the units to velocity dimensions, and the inverse component of the velocity dimension is calculated as signal 95.

[0113] By adding signal 95 to the adder / subtractor 64, the inverse phase of the vibration of the mechanical end 17 can be subtracted from the speed command 14 by the adder / subtractor 54, thus realizing FB-type vibration reduction control.

[0114] Figure 2 , Figure 5 , Figure 6 , Figure 8 and Figure 9 In the structure, the position command estimator 5 is based on equation (2), but the position command estimator can also be changed to the signal obtained by mapping the calculated value of the position command with a specified filter.

[0115] For example, if the specified filter is a unit converter, it has the advantage of simplifying the computational processing. An example of a unit converter, as mentioned above, is the position controller 7, which is the inverse characteristic of Fp. Thus, by processing both sides of equation (2) with the inverse characteristic of Fp, we obtain equation (5).

[0116] [Mathematical Expression 5]

[0117]

[0118] Where rep is the signal obtained by mapping the calculated value re of the position command using a specified filter (the inverse characteristic of Fp). The output signal 1002 of the position command estimator 1001 is rep of equation (5).

[0119] Figure 10 The structure is for Figure 9 The structure adopts the position command calculator 1001 shown in equation (5).

[0120] The position command estimator 1001 takes the signal obtained by mapping the position command generated by the upper-level system control device 2 with a specified filter as the estimating object and outputs the estimating value of the signal obtained by mapping the position command with the specified filter.

[0121] When using a position instruction calculator 1001 like this, such as Figure 10As shown, the parallel vibration damping controller 23 does not require a unit converter. Additionally, Figure 10 In the mechanical end vibration characteristic model 92, the input signal 1003 is calculated in the position command estimator 1001 based on the second term yp / Fp on the right side of equation (5). Let the motor shaft position response be yp and the estimating filter consistent with the inverse characteristic of the position controller 7 be Fp. yp / Fp is obtained from the position command estimator 1001 as signal 1003.

[0122] right Figure 9 Structure and Figure 10 Comparison, Figure 10 Because it eliminates the need for unit converters in various locations, it simplifies the process.

[0123] Figure 2 , Figure 8 In the structure, the vibration damping controller within the speed control system processes the speed command 14 for vibration damping at the mechanical end, but as... Figure 11 As shown, vibration reduction at the mechanical end can also be achieved by machining the motor shaft position response 15.

[0124] Figure 11 In this system, the parallel vibration damping controller 1101 consists of a vibration excitation component extractor 52 that extracts the frequency components of the vibration at the end of the excitation machinery included in the speed command 14, and a predefined filter 1102 that processes the extracted frequency components. The output signal 1105 of the parallel vibration damping controller 1101 is added by the adder / subtractor 1107 in response to the motor shaft position response 15. The output signal 1106 of the adder / subtractor 1107 is the output of the vibration damping controller 1108 within the speed control system, and is output to the upper-level system control device 2 as the actual motor shaft position response 1106.

[0125] In the case that the vibration-excited component extractor 52 is the LE of equation (1), Figure 11 The specified filter 1102 is given by the following formula.

[0126] [Mathematical Expression 6]

[0127] Specified filter

[0128] When the filter is specified as Equation (6), the FF-type vibration reduction control effect, which removes the frequency components of the vibration at the excitation mechanical end from the position command 13, can be obtained through the position FB loop. Therefore, Figure 11 The vibration damping controller 1108 in the speed control system that processes the motor shaft position response 15 shown can also achieve vibration damping control to suppress vibration at the mechanical end.

[0129] Figure 12 express Figure 5 The effect of vibration reduction control on the mechanical end of the structure described in the paper. Figure 12 The vertical axis represents the position response (rad) of the mechanical end, and the horizontal axis represents time (s). Relative to the position command 1201, the mechanical end position response 1202 without any vibration damping control is oscillating from the start, and the oscillation is also significant after the setpoint of 0.2 [sec].

[0130] on the other hand, Figure 5 In the vibration reduction control described in this embodiment, the vibration of the mechanical end is suppressed from the moment it rises, and the vibration is also suppressed after a stable period of 0.2 [sec]. Therefore, according to... Figure 12 It can be seen that the vibration reduction control implemented in this case is sufficiently effective.

[0131] According to this embodiment, in a semi-enclosed motor control system, the upper-level system control device has a position controller. Instead of processing position commands for mechanical vibration reduction within the upper-level system control device, vibration reduction control is achieved within the motor servo control device responsible for the speed control system. This improves the response of the control system and reduces cycle time.

[0132] Furthermore, this embodiment envisions a controlled mechanical system that is a two-inertial system, but it could also be a three-inertial system or more multi-inertial systems. This can be addressed by extending the parallel vibration reduction control.

[0133] Furthermore, the parallel vibration damping controller can be a structure formed by arbitrarily combining FF-type vibration damping control and FB-type vibration damping control. Based on Figure 5 , Figure 6 , Figure 9 The parallel vibration damping controller described herein can combine FF-type vibration damping control with FB-type vibration damping control.

[0134] Example 2

[0135] The motor control device in Example 2 is conceived as... Figure 13 The diagram shows the application of a cascaded position FB control system for an AC servo motor, consisting of a higher-level system control device 2 and a servo motor control device 3.

[0136] The vibration damping controller 21 in the speed control system shown in Example 1 is applied to... Figure 13 The situation is Figure 14 .

[0137] Figure 14The cascade position FB control system of the AC servo motor includes adder / subtractor 1312 and adder / subtractor 1314, position controller 1315, speed controller 132, current controller 133, first coordinate transformer 134 for coordinate transformation from dq coordinate system to three-phase coordinate system, second coordinate transformer 1310 for coordinate transformation from three-phase coordinate system to dq coordinate system, PWM output device 135 for inputting three-phase voltage command and outputting PWM pulse, inverter (power converter) with switching element 136, current detector 138, position / speed calculator 1311, vibration damping controller 21 in speed control system, encoder 139 for measuring motor speed, motor 137, and mechanical device 1313 driven by motor.

[0138] The vibration damping controller 21 in the speed control system takes into account the motor shaft position response calculated by the position / speed calculator 1311 based on the output of the encoder 139 and the position operation amount from the position controller 1315, outputs the motor shaft position response to the position controller 1315, and outputs the speed command to the speed controller 132.

[0139] The circuit part of the current controller 133 controls the motor. Under the premise that the control cycle is faster than that of the speed controller 132, the current control system is approximately regarded as 1 in the speed control system (the operation of the speed controller 132 is directly transmitted to the mechanical part (rotor) of the motor 137).

[0140] Therefore, the speed controller 132 controls the mechanical part (rotor) of the motor 137 and the mechanical component 1313 connected to the motor rotor, which is equivalent to... Figure 1 The control object of the FB controller in the system.

[0141] Furthermore, given that the control cycle of the speed controller 132 is faster than the control cycle of the position controller 1315, the speed control system is approximated as 1 in the position control system.

[0142] The vibration damping controller 21 in the speed control system is located at the front end of the speed control system. It processes the output of the upper-level system control device 2, i.e. the speed command, and generates commands for the speed controller 132.

[0143] Assuming the inertia number of mechanical 1313 is 1, and with mechanical 1313 elastically connected to the motor rotor, the controlled object can be regarded as a two-inertial system formed by connecting mechanical 1313 and motor rotor with springs and dampers. The controlled object has frequency characteristics including one set of resonant / anti-resonant characteristics.

[0144] In addition, the mechanical 1313 has an inertia number of 2. Each inertia is combined with a spring and a damper. When one of them is elastically connected to the motor rotor, the controlled object can be regarded as a three-inertia system that combines each inertia with a spring and a damper, and has frequency characteristics including two sets of resonant / anti-resonant characteristics.

[0145] Assume that mechanical 1313 has low rigidity and exhibits resonant / anti-resonant characteristics in the low-frequency range of several Hz to 100 Hz.

[0146] First, consider the state of the vibration damping controller 21 within the speed control system. Figure 13 To increase the control gain of the position controller 1315 and control the motor shaft position response from the position command to the motor 137 with high responsiveness, when using a setting to suppress vibrations caused by the resonant / anti-resonant characteristics of the mechanical 1313, the ends of the mechanical 1313 become vibratory due to the low rigidity of the mechanical 1313.

[0147] On the other hand, such as Figure 14 As shown, when the vibration damping controller 21 is included in the speed control system, as described in Example 1, the vibration damping effect of the mechanical end can be achieved, for example, as shown in Example 1. Figure 12 The vibration reduction effect shown is sufficient.

[0148] Therefore, according to this embodiment, in a semi-enclosed AC servo motor control system, it is possible to provide a motor control device in which the upper-level system control device has a position controller, and the processing of position commands for the purpose of mechanical end vibration reduction is not performed in the upper-level system control device, but rather the motor servo control device responsible for the speed control system has a unit for realizing vibration reduction control.

[0149] In addition to AC servo motor control, DC motor control also uses a cascade control structure formed by speed / position controllers. Therefore, according to this embodiment, by inserting a vibration damping controller 21 into the front end of the speed controller, vibration damping at the mechanical end can be achieved within the speed control system.

[0150] The above embodiments can also be applied to, in addition to electric motor control devices, semiconductor inspection devices, main electric motor control devices for electric vehicles, electric power steering, etc.

[0151] Explanation of reference numerals in the attached figures

[0152] 2… Upper-level system control device, 3… Servo motor control device, 5… Position command calculator, 10… Position / speed calculator, 13… Position command, 14… Speed ​​command, 15… Motor shaft position response, 21… Vibration damping controller within the speed control system, 23… Parallel vibration damping controller, 52… Vibration excitation component extractor.

Claims

1. A motor control device capable of receiving speed commands from a higher-level system control device having a position controller, characterized in that, include: A position command estimator that calculates the estimated value of the position command based on the speed command and the motor shaft position response; and A speed command generator that generates an actual speed command based on the calculated value to prevent vibration at the end of the machinery connected to the electric motor. The actual speed command is output from the speed command generator to the speed controller.

2. The motor control device as described in claim 1, characterized in that: The speed command generator includes: A vibration frequency component extractor for extracting the frequency components of the end vibrations that excite the machine; and A real position controller that receives a position command that does not contain a frequency component that excites the end vibration of the machine to generate the actual speed command.

3. A motor control device capable of receiving speed commands from a higher-level system control device having a position controller, characterized in that, include: A position command estimator that calculates the estimated value of the position command based on the speed command and the motor shaft position response; A parallel vibration damping controller, based on the calculated value, extracts the frequency components of the end vibration of the machine connected to the motor that are included in the speed command, and outputs the extracted frequency components. and The adder / subtractor that subtracts the output of the parallel vibration damping controller from the speed command. The output of the adder / subtractor is used as the actual speed command and as the command for the speed controller.

4. The motor control device as described in claim 3, characterized in that: The parallel vibration damping controller calculates the inverse component of the vibration component at the end based on the estimated value and the motor shaft position response, and outputs the inverse component to the adder / subtractor.

5. The motor control device as described in claim 3, characterized in that: The location command calculator includes: The calculation filter inputting the speed command has characteristics consistent with the inverse characteristics of the position controller; and An adder that adds the output of the estimation filter to the motor shaft position response.

6. The motor control device as described in claim 3, characterized in that: The parallel vibration damping controller includes: A vibration excitation component extraction filter that extracts, without phase delay, the frequency component of the vibration exciting the end of the machine contained in the speed command from the calculated value; and A unit converter that converts the units of the frequency components extracted by the vibration excitation component extraction filter into velocity dimensions. The output of the unit converter is used as the output of the parallel vibration damping controller.

7. The motor control device as described in claim 4, characterized in that: The parallel vibration damping controller includes: The specified position command is defined as a vibration-free, required standard response model. A mechanical end vibration characteristic model representing the transmission characteristics from the motor shaft to the mechanical end; The third adder / subtractor; and A unit converter that converts the units of the input signal to the units of velocity. The third adder / subtractor removes from the signal processed by the mechanical end vibration characteristic model for the motor shaft position response the signal processed by the mechanical end vibration characteristic model the signal processed by the position command estimator output by the standardized response model. The signal after processing the output signal of the third adder / subtractor with the unit converter is used as the inverse component of the vibration component at the end and is used as the output of the parallel vibration damping controller.

8. The motor control device as described in claim 3, characterized in that: The position command estimator takes the signal obtained by mapping the position command with a specified filter as the estimating object and outputs the estimated value of the signal obtained by mapping the position command with a specified filter.

9. The motor control device as described in claim 3, characterized in that: The parallel vibration damping controller outputs an extracted signal obtained by extracting the frequency component of the excitation mechanical end vibration contained in the speed command. The parallel vibration damping controller, It features a fourth adder / subtractor, scalar gain adjustment, and a differentiator. The extracted signal is subtracted from the calculated value of the position command using the fourth adder / subtractor, and the output signal of the fourth adder / subtractor is processed by the adjustment gain and the differentiator to obtain the feedforward control signal, which is then output. The feedforward control signal is added to the speed command using the fifth adder / subtractor, and the extracted signal is removed from the speed command using the fifth adder / subtractor. The output of the fifth adder / subtractor is then used as the actual speed command.

10. The motor control device as described in claim 3, characterized in that: The parallel vibration damping controller includes: A vibration excitation component extractor that extracts the frequency component of the end vibration of the machine contained in the speed command; The specified position command is defined as a vibration-free, required standard response model. A mechanical end vibration characteristic model representing the transmission characteristics from the motor shaft to the end; The third adder / subtractor; and A unit converter that converts the units of the input signal to the units of velocity. The third adder / subtractor removes from the signal processed by the mechanical end vibration characteristic model for the motor shaft position response the signal processed by the mechanical end vibration characteristic model the signal processed by the position command estimator output by the standardized response model. The signal obtained by processing the output signal of the third adder / subtractor using the unit converter is output as the inverse component of the vibration component at the end. The signal obtained by removing the frequency component that excites the end vibration contained in the speed command is removed using the sixth adder / subtractor, and the inverted component is removed from the speed command using the sixth adder / subtractor. The output of the sixth adder / subtractor is then used as the actual speed command.

11. The motor control device as described in claim 8, characterized in that: The position command calculator includes the specified filter and adder. The speed command is added to the signal after the motor shaft position response has been processed by the specified filter using the adder. The output signal of the adder is used as the output of the position command calculator. The parallel vibration damping controller extracts the frequency component that excites the end vibration of the machine from the output of the position command calculator and uses it as an output signal.

12. A motor control device capable of receiving speed commands from a higher-level system control device having a position controller, characterized in that, include: A position command estimator that calculates the estimated value of the position command based on the speed command and the motor shaft position response from the motor. A parallel vibration damping controller extracts the frequency components of the end vibration of the excitation machinery contained in the speed command based on the calculated value of the position command, and outputs a signal after the extracted frequency components have been processed by a specified filter. and Adder The adder is used to add the motor shaft position response to the output of the parallel vibration damping controller. The output signal of the adder is used as the actual motor shaft position response, and the actual motor shaft position response is output to the position controller.

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