Controller for setting control parameter and Method for setting control parameter of controller

Abstract

The present invention provides a control device comprising: a control unit that transmits a control signal to a load to control the load; a disturbance generating unit that generates a first signal and a second signal by modulating the frequency and transmits them to the load; an analysis unit that analyzes a sensing current that senses a current output from the load; and a processing unit that sets control parameters of the control unit using the results of analyzing the sensing current, wherein the disturbance generating unit continuously generates the first signal and the second signal, the first signal is a signal whose frequency increases or decreases over time, and the second signal is a signal whose frequency is constant over time.

Description

Technology Field

[0001] The embodiment relates to a control device for setting control parameters and a method for setting control parameters. Background Technology

[0002] Motors possess inherent characteristics such as resistance, inductance, and friction. These characteristic values ​​are utilized, either through measurement or design, to design position, speed, and current control logic. However, deviations exist between design values ​​and manufactured products, and even measured values ​​may be subject to measurement errors.

[0003] The motor characteristic values ​​mentioned above exhibit deviations depending on the sample and can vary due to temperature or aging. Currently, to incorporate these characteristics into the control system, controller values ​​are designed by measuring motor characteristics using multiple samples under various conditions during the development phase. However, this method introduces errors between actual samples, which consequently prevents the achievement of optimal control performance.

[0004] Due to these issues, control performance deteriorates below the design value depending on deviations between samples, temperature changes, and aging. The problem to be solved

[0005] Accordingly, the embodiment is intended to solve the aforementioned problem and provides a control device and a method for setting control parameters that can significantly reduce the signal transmission and reception period by using a frequency-modulated signal to set control parameters.

[0006] The problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] An embodiment may provide a control device comprising: a control unit that transmits a control signal to a load to control the load; a disturbance generating unit that generates a first signal and a second signal by modulating the frequency and transmits them to the load; an analysis unit that analyzes a sensing current that senses a current output from the load; and a processing unit that sets control parameters of the control unit using the results of analyzing the sensing current. The disturbance generating unit continuously generates the first signal and the second signal, and the first signal is a signal whose frequency increases or decreases over time, and the second signal is a signal whose frequency remains constant over time.

[0008] An embodiment may provide a method for setting control parameters, comprising the steps of: a disturbance generating unit generating a first signal and a second signal of frequency; transmitting the first signal and the second signal to a load along with a control signal generated by a control unit; sensing a current output from the load; analyzing the sensed sensing current; and setting control parameters of the control unit using the result of analyzing the sensed current, wherein the first signal is a signal whose frequency increases or decreases over time, and the second signal is a signal whose frequency remains constant over time. Effects of the invention

[0009] According to the embodiment, there is an advantage in that it is possible to design optimal controller values ​​(P, I, D Gain and Filter).

[0010] According to the embodiment, even if the characteristics of the motor change as the operating environment of the motor (temperature, aging, etc.) changes, the characteristics of the motor can be measured online to obtain an optimal control value, and there is an advantage in that the control performance (ripple in the steady state, responsiveness in the transient state, etc.) can always be maintained optimally.

[0011] According to the embodiment, there is an advantage of significantly reducing the transmission and reception time of the first signal and the second signal for verifying frequency response characteristics.

[0012] According to the embodiment, there is an advantage of being able to measure stable response characteristics while reducing the signal transmission and reception time.

[0013] According to the embodiment, there is an advantage of preventing the temperature of the motor by reducing the signal transmission and reception time. Brief explanation of the drawing

[0014] FIG. 1 is a block diagram illustrating the operation of a controller according to a comparative example with the present invention, FIG. 2 is a block diagram of a control device according to an embodiment of the present invention, FIG. 3 is a block diagram of a control device according to another embodiment of the present invention, FIG. 4 is a diagram illustrating the waveforms of the first signal and the second signal. FIG. 5 is a block diagram explaining the operation process of a control device, FIG. 6 is a flowchart illustrating a method for setting control parameters according to an embodiment of the present invention. Specific details for implementing the invention

[0015] FIG. 1 is a block diagram illustrating the operation of a controller according to a comparative example with the present invention. In a controller that drives a load such as a motor, the controller (10) applies a voltage to drive the motor to the motor (21) through a voltage output (15) in a position / speed / current control logic (11).

[0016] And the controller (10) senses the current measurement (15) through the current flowing according to the applied voltage, and uses the sensed sensed current to drive the motor (21) in the position / speed / current control logic (11).

[0017] The position / speed / current control logic (11) has control parameters set to drive the motor (21). The control parameters are set using the motor's characteristic values ​​or design values. In this case, if design values ​​are used, a deviation may occur between the design values ​​and the manufactured product, and the motor's characteristic values ​​may change due to temperature fluctuations or aging. Therefore, it is difficult to achieve optimal control performance with the control parameters of the existing position / speed / current control logic (11).

[0018] In order to achieve optimal control performance even if errors or changes in load characteristics occur due to load characteristics, a control device according to one embodiment of the present invention can set or change control parameters using frequency response analysis.

[0019] Hereinafter, a control device for setting control parameters and a method for setting control parameters according to an embodiment of the present invention will be described.

[0020] FIG. 2 is a block diagram of a control device according to one embodiment of the present invention, and FIG. 3 is a block diagram of a control device according to another embodiment of the present invention.

[0021] A control device (100) according to one embodiment of the present invention includes a control unit (110), a disturbance generation unit (120), an analysis unit (130), and a processing unit (140), and may include a voltage output unit (150), a current measurement unit (160), a storage unit (131), and an FFT conversion unit (132).

[0022] The control unit (110) transmits a control signal to the load (210) to control the load (210).

[0023] More specifically, the control unit (110) controls the load (210) according to set control parameters and transmits a control signal to the load (210) to control the load (210). The load (210) connected to the control device (100) may be an actuator. Here, an actuator is a driving device that operates a device using power, and refers to a motor operated by a predetermined control unit or a piston or cylinder mechanism operated by hydraulic or pneumatic pressure. The load (210) may be a motor, and the control device (100) may be a motor driving device that drives the motor.

[0024] The control unit (110) is a Micro Controller Unit (MCU), and the disturbance generation unit (120), analysis unit (130), and processing unit (140) can be implemented as processors within the MCU. That is, the disturbance generation unit (120), analysis unit (130), and processing unit (140) can be implemented as software on a processor included in an MCU embedded in a vehicle, etc., or can be implemented in the form of hardware of a Companion Chip. When implemented in the form of hardware, they can be formed as a single piece of hardware or as separate pieces of hardware.

[0025] Figure 4 is a diagram showing the waveforms of the first signal and the second signal.

[0026] Referring to FIGS. 2 to 4, a disturbance generating unit (120) generates a first signal (S1) and a second signal and transmits them to a load (210). Here, the first signal (S1) is a signal whose frequency increases or decreases over time. For example, the first signal (S1) may be a chirp wave. The second signal is a signal whose frequency remains constant over time. For example, the second signal may be a sine wave. Here, a sine wave refers to a signal whose waveform is a sine curve, and is also called a sine wave.

[0027] The disturbance generating unit (120) can sequentially generate a first signal (S1) and a second signal. The disturbance generating unit (120) can generate a signal in a low frequency band as the first signal (S1) and a signal in a high frequency band as the second signal. The low frequency band is a frequency band in which a horizontal response occurs in the frequency response of the load (210), and the high frequency band is characterized by being a fractional value frequency that has little interference effect when the load (210) rotates.

[0028] If it is necessary to reset or change the control parameters, the control unit (110) can control the disturbance generation unit (120) to generate a first signal (S1) and a second signal (S2). Alternatively, the upper controller (220) can cause the disturbance generation unit (120) to generate the first signal (S1) and the second signal (S2) through a mode operation signal. When setting control parameters during the production process, the production device (220) can control the disturbance generation unit (120) to generate the first signal (S1) and the second signal (S2). Upon receiving the mode operation signal, the disturbance generation unit (120) generates the first signal (S1) and the second signal (S2) and transmits them to the load (210).

[0029] The disturbance generating unit (120) can generate a signal as a first signal (S1) such that the frequency increases over time in response to a certain time (T1). That is, the first signal (S1) may have an end frequency greater than the start frequency. The first signal (S1) has a frequency (f1) during a certain time (T1). <f2<f3<f4…)가 증가한다. 그리고 외란 발생부(120)는 제1 신호(S1)에 연속하여 제2 신호(S2)를 생성할 수 있다. 제2 신호(S2)는 일정시간(T2)동안 주파수(f0)가 일정하다.

[0030] The first signal (S1) can be generated by the following mathematical formula 1.

[0031]

[0032] The second signal (S2) can be generated by the following mathematical formula 2.

[0033]

[0034] For example, the starting frequency of the chirp wave can be 1 Hz, the ending frequency can be 10 Hz, and the frequency of the sine wave can be 113 Hz.

[0035] Since the frequency of the first signal (S1) increases in response to the set time, the signal injection time is determined at a constant time regardless of the magnitude of the frequency. Therefore, the signal injection time is fast, allowing for transmission and reception within a short period. For example, when using a sinusoidal wave, the transmission and reception time takes about 10 seconds. However, when using the first signal (S1) in the form of a chirp wave, the time can be significantly reduced to 0.7 seconds.

[0036] Because the signal injection time is fast, the temperature rise of the load (210) caused by the signal injection can be reduced.

[0037] However, in the case of the first signal (S1), it may have an unstable response value in the high-frequency band, and by configuring the high-frequency band with the second signal (S2), a stable response value can be secured.

[0038] The disturbance generating unit (120) can generate a first signal (S1) which is a chirp wave, and then generate a second signal (S2) which is a sinusoidal wave. Alternatively, the disturbance generating unit (120) can generate a second signal (S2) which is a sinusoidal wave, and then generate a first signal (S1) which is a chirp wave.

[0039] Meanwhile, since the first signal (S1) and the second signal (S2) are of different types, discontinuous phase values ​​may be output. Because the current or voltage may be unstable due to the discontinuous phase values, in order to prevent this, the disturbance generating unit (120) can ensure phase continuity by setting the last phase value of the signal that occurs relatively earlier as the phase value of the second signal. For example, if the first signal is generated first, the phase value of the second signal can be set as the last phase value of the first signal.

[0040] The disturbance generating unit (120) can periodically generate these first signal (S1) and second signal (S2). Even without receiving a mode operation signal from the control unit (110), the upper controller (220), or the production equipment (220), the first signal (S1) and second signal (S2) can be periodically generated for periodic control parameter updates. The period of the first signal (S1) and second signal (S2) can be set in months or years for the purpose of updating control parameters. The period of the first signal (S1) and second signal (S2) can vary depending on the characteristics of the load (210) connected to the control device (100) or the characteristics of the control device (100), and can be set by the user. Alternatively, the disturbance generating unit (120) can continuously generate the first signal (S1) and second signal (S2). The load (210) receives a control signal from the control unit (110) and receives a first signal (S1) and a second signal (S2) from the disturbance generation unit (120). The load (210) may receive the control signal and the first signal (S1) and the second signal (S2) together. At this time, the frequency of the first signal (S1) and the frequency of the second signal (S2) may be different from the frequency of the control signal of the control unit. The control signal for driving the load (210) and the frequency of the first signal (S1) and the frequency of the second signal (S2) for setting control parameters must be distinguished. Accordingly, the disturbance generation unit (120) can generate a first signal (S1) and a second signal (S2) having a frequency different from the control signal. The disturbance generation unit (120) can generate the first signal (S1) and the second signal (S2) to include at least one frequency different from the control signal. The disturbance generating unit (120) can generate signals excluding signals having the same frequency as the control signal when generating the first signal (S1) and the second signal (S2). The response to the corresponding frequency can already be received from the control signal and analyzed.

[0041] Alternatively, a signal including a frequency such as the frequency of the control signal may be generated. Or, the load (210) may receive the control signal and the first signal (S1) and the second signal (S2) independently through separate input lines, or they may be received with different input cycles.

[0042] The control signal of the control unit (110), the first signal (S1), and the second signal (S2) can be transmitted to the load (210) through the voltage output unit (150). The voltage output unit (150) can convert the control signal of the control unit (110), the first signal (S1), and the second signal (S2) into voltage signals and transmit them to the load (210). The load (210) may be a device that receives the voltage and operates, for example, a motor.

[0043] In order to apply voltage to a load (210), the voltage output unit (130) receives control signals, a first signal (S1) and a second signal (S2), and can transmit a voltage corresponding to a corresponding frequency to the load (210) according to the frequencies of the control signal, the first signal (S1), and the second signal (S2). The voltage output unit (130) may be a bridge circuit formed by a plurality of switches. The upper switch and the lower switch forming the bridge conduct complementarily, and can transmit a three-phase voltage to the load (210) with a phase difference in each bridge circuit.

[0044] The current measuring unit (140) senses the current output from the load. The current measuring unit (140) is connected to the output line of the load (210) to sense the current. The current can be formed using a current measuring element such as a shunt resistor. Alternatively, the current output from the load (210) can be sensed using various devices such as a current mirror circuit and a voltage measuring device.

[0045] The sensed current sensed by the current measuring unit (140) can be used to generate a control signal in the control unit (110) and to analyze the frequency response to the control parameter in the analysis unit (130).

[0046] The analysis unit (150) can analyze the received sensing current by performing a Fast Fourier Transform on the sensing current. The Fast Fourier Transform (FFT) is a method for processing the Fourier Transform of discrete data at high speed and is used to analyze signals. By using the Fast Fourier Transform, fast processing is possible by reducing the number of time-consuming multiplications by sequentially decomposing the Discrete Fourier Transform of a long signal series into the Discrete Fourier Transform of a shorter signal series and changing the order of data using the symmetry and periodicity of the rotation factor.

[0047] The analysis unit (150) can perform a Fast Fourier Transform using the received sensing current and the first signal (S1) and second signal (S2) transmitted to the load (210) by the disturbance generating unit (120). In performing the Fast Fourier Transform, the analysis unit (150) may be composed of a storage unit (151) that stores the first signal (S1), the second signal (S2), or the sensing current, and an FFT transform unit (152) that performs a Fast Fourier Transform using the first signal (S1), the first signal (S1), and the sensing current.

[0048] The first signal (S1) and the second signal (S2) are stored in the storage unit (151). When a sensing current corresponding to the stored first signal (S1) or second signal (S2) is received, the FFT transform unit (152) can perform a fast Fourier transform using the received sensing current and the stored first signal (S1) or second signal (S2).

[0049] The FFT transform unit (152) can determine the frequency response characteristics of the load (210) through the Fast Fourier Transform. Frequency response is a measure of what kind of response is output when an input signal of various frequencies is applied to a system, and is used to analyze the system. Here, the amplitude of the signal may be constant or vary. Frequency response can represent the amplitude and phase of the signal output from the system as a curve against frequency.

[0050] The processing unit (160) sets the control parameters of the control unit (110) using the results of analyzing the sensing current.

[0051] More specifically, the processing unit (160) receives the results of analyzing the sensing current from the analysis unit (150). The analysis unit (150) analyzes the sensing current through a Fast Fourier Transform and transmits the analyzed results to the processing unit (160). The processing unit (160) can calculate the control parameters of the control unit (110) using the results of analyzing the sensing current. The calculated control parameters can be transmitted to the control unit (110) to change or set the control parameters of the control unit (110).

[0052] The processing unit (160) can calculate the PI control parameter, PID control parameter, or filter coefficient of the control unit (110) using the result of analyzing the sensing current.

[0053] The processing unit (160) can calculate PI control parameters if the control unit (110) is a PI controller, calculate PID control parameters if the control unit (110) is a PID controller, and calculate filter coefficients if a filter is included. The control unit (110) may be an automatic controller and may control using a combination of P, I, and D.

[0054] Here, P stands for Proportional, I for Integral, and D for Differential. Proportional (P) control is a control method in which the controlled variable is proportional to the difference between the target value and the current position. According to proportional control, as the control value approaches the target value, the difference between the control values ​​decreases, enabling finer control. However, when the controlled variable approaches the target value, it becomes too small to allow for further fine control, resulting in a residual deviation that remains uncontrollable.

[0055] PI control is a control method that utilizes proportionality and integral operation. It eliminates minute residual deviations by accumulating them over time and increasing the control amount based on the accumulated deviation; it is a control method that adds integral action to proportional action. Residual deviations can be eliminated using PI control. While PI control allows for control close to the actual target value, the control amount decreases as the system approaches the target value, requiring operation for a certain period of time. In this case, if the integer is large, the response performance in the event of disturbances may deteriorate. In other words, it may be difficult to respond quickly to disturbances and return to the target value. To resolve this, derivative action can be performed. In response to sudden disturbances, the deviation is monitored, and if the difference from the previous deviation is large, the control amount is increased to provide a response. Observing the change in the deviation from the previous period corresponds to differentiation, and PID control is performed by applying differentiation to proportionality and integral. Even if the control amount deviates from the target value, it can be judged as a deviation from the previous period and the control amount is applied, allowing the system to quickly reach the target value.

[0056] PID control can be expressed as a PID control equation, and PID control parameters can be represented as Kp, Ki, and Kd. PID parameters can be calculated through optimization using the step response method or the limit damping method. Correspondingly, PI control can also calculate PI control parameters Kp and Ki.

[0057] The processing unit (160) can transmit the calculated control parameter to the control unit (110) so that the control unit (110) can set or change the control parameter of the control unit (110) using the calculated control parameter. The control parameter calculated by the processing unit (160) is a control parameter calculated while the load (210) is connected. That is, it is a control parameter that is adaptively calculated by reflecting characteristic values ​​such as temperature or aging of the load (210), and corresponds to the optimal control parameter of the control unit (110).

[0058] FIG. 5 is a block diagram explaining the operation process of a control device, and FIG. 6 is a flowchart illustrating a method for setting control parameters according to an embodiment of the present invention.

[0059] Referring to FIGS. 5 and 6, the control device (100) may be a control device that drives a load motor (210) and includes an FRA online calibration function that performs a frequency response using a first signal (S1) and a second signal (S2). The control device (100) is connected to the motor (210), and if the motor is a three-phase motor, the three phases are connected, and if it is a DC motor, + and - may be connected.

[0060] When the control device (100) receives a calibration operation signal from the production device or the upper controller (220), it generates a first signal (S1) of chirp wave (S100) and applies the generated first signal (S1) to the voltage output unit (130) (S200). The current measurement unit (140) measures the current output from the load (210) (S300). The analysis unit (150) performs a Fast Fourier Transform on the sensing current and the first signal (S1) (S400).

[0061] The control device (100) generates a first signal (S1) and then continuously generates a second signal (S2) (S100). (S100) The control device (100) applies the generated second signal (S2) to the voltage output unit (130). (S200) The current measurement unit (140) measures the current output from the load (210). (S300) The analysis unit (150) performs a Fast Fourier Transform on the sensing current and the second signal (S2). (S400)

[0062] The processing unit (160) calculates the control parameters of the control unit (110) using the results of analyzing the sensing current. (S500)

[0063] Meanwhile, embodiments of the present invention can be implemented as computer-readable code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer system is stored.

[0064] Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. Additionally, computer-readable recording media may be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner. Furthermore, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the technical field to which the present invention belongs. Explanation of the symbols

[0065] 100: Control unit 110: Control unit 120: Disturbance source 130: Voltage output section 140: Current output section 150: Analysis Department 160: Processing unit

Claims

Claim 1 A control device comprising: a control unit that transmits a control signal to a load to control the load; a disturbance generating unit that generates a first signal and a second signal by modulating the frequency and transmits them to the load; an analysis unit that analyzes a sensing current that senses a current output from the load; and a processing unit that sets control parameters of the control unit using the results of analyzing the sensing current, wherein the disturbance generating unit generates the first signal and the second signal, the first signal is a signal whose frequency increases or decreases over time, and the second signal is a signal whose frequency is constant over time, and the last phase value of the signal that occurs relatively earlier among the first signal and the second signal is set as the phase value of the second signal. Claim 2 A control device according to claim 1, wherein the first signal is a chirp wave and the second signal is a sinusoidal wave. Claim 3 In claim 1, the disturbance generating unit is a control device that sets the last phase value of the first signal to the first phase value of the second signal. Claim 4 A control device according to claim 1, wherein the disturbance generating unit receives a mode operation signal from the control unit, production device, or upper controller and generates the first signal and the second signal. Claim 5 A control device according to claim 1, characterized in that the frequency of the first signal and the frequency of the second signal are each different in frequency from the control signal of the control unit. Claim 6 A control device according to claim 1, comprising: a voltage output unit that converts a control signal of the control unit, the first signal, and the second signal into a voltage signal and transmits it to the load; and a current measuring unit that senses a current output from the load. Claim 7 A control device according to claim 1, wherein the analysis unit comprises: a storage unit that stores the first signal, the second signal, and the sensing current; and an FFT transform unit that performs a Fast Fourier Transform using the first signal, the second signal, and the sensing current. Claim 8 A control device according to claim 1, wherein the processing unit calculates the PI parameter, PID parameter, or filter coefficient of the control unit using the result of analyzing the sensing current. Claim 9 A control device according to claim 1, wherein the processing unit sets the control parameters of the control unit using the inductance and impedance of the load derived from the result of analyzing the sensing current. Claim 10 A method for setting control parameters comprising: a step of generating a first signal and a second signal of frequency by a disturbance generating unit; a step of transmitting the first signal and the second signal to a load together with a control signal generated by a control unit; a step of sensing a current output from the load; a step of analyzing the sensed sensing current; and a step of setting control parameters of the control unit using the result of analyzing the sensed current, wherein the first signal is a signal whose frequency increases or decreases over time, and the second signal is a signal whose frequency is constant over time, and the last phase value of the signal that occurs relatively earlier among the first signal and the second signal is set as the phase value of the second signal.

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