Control device, test device and magnetic field control method of magnetic field generator

Abstract

The present invention provides a control device, a test device and a magnetic field control method for a magnetic field generator that optimize the response characteristics of a control system. The control device includes a magnetic field control circuit (60) that controls a magnetic field generator (30) based on a detection value of a magnetic field sensor (40). In the magnetic field control circuit (60), a command value of a magnetic field generated by the magnetic field generator (30) is input, and a detection value of the magnetic field sensor (40) is fed back and input. An error signal is generated according to an error between the command value and the detection value, and a control signal after the error is amplified by a control gain is output to the magnetic field generator (30). In addition, the control gain includes: a gain having a characteristic that the higher the frequency of the error signal, the smaller the gain; and a gain having a characteristic that the larger the amplitude of the error signal, the larger the gain.

Description

Technical Field

[0001] The invention relates to a control device, a test device and a magnetic field control method of a magnetic field generator. Background Art

[0002] A PID control device that automatically sets PID parameters is known (for example, refer to patent document 1). In this PID control device, when the PID control unit is set to a P control state and the target value input is set to a constant state, the automatic tuning unit gradually increases the proportional gain Kp of the PID control unit. As Kp increases, vibrations are generated in the deviation. The FFT analysis unit performs frequency analysis on the deviation and detects the natural vibration frequency included in the deviation from the peak frequency. The filter removes noise components with frequencies higher than the natural vibration frequency and outputs them to the RMS processing unit. The RMS processing unit calculates the effective value for each cycle of the vibration of the deviation, and when a continuous increase in multiple cycles is detected, a trigger signal is sent to the automatic tuning unit to reduce the value of Kp of the PID control unit. When the automatic tuning unit receives the trigger signal, the PID parameters are determined based on the proportional gain Kpc and the period Tc of the natural vibration at this time.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-113111 Summary of the invention

[0006] (Problems to be solved by the invention)

[0007] The PID control device described in Patent Document 1 has a problem in that the response characteristics of the control system cannot be dynamically optimized when the speed requirement range of the feedback control is wide.

[0008] An object of the present invention is to provide a control device, a test device, and a magnetic field control method for a magnetic field generator that optimize the response characteristics of a control system.

[0009] (Technical solutions to solve problems)

[0010] [1] The control device of the magnetic generator of the present invention comprises a magnetic field control circuit, which controls the magnetic field generator based on the detection value of a magnetic field sensor that detects the magnetic field, the magnetic field control circuit is input with a command value of the magnetic field generated by the magnetic field generator, the detection value of the magnetic field sensor is fed back and input to the magnetic field control circuit, the magnetic field control circuit generates an error signal according to the error between the command value and the detection value, the magnetic field control circuit outputs a control signal to the magnetic field generator after amplifying the error with a control gain, the control gain comprising: a first gain, which comprises a characteristic that the higher the frequency of the error signal, the smaller the gain; and a second gain, which comprises a characteristic that the larger the gain, the larger the amplitude of the error signal.

[0011] [2] In the above invention, the second gain can also be set based on the command value responsiveness required to the change of the command value, the output value responsiveness required to the output change of the magnetic field generator, and the detection value responsiveness required to the change of the detection value of the magnetic field sensor.

[0012] [3] In the above invention, the second gain may further include a characteristic that the gain increases continuously with respect to an increase in the amplitude.

[0013] [4] The test device according to the present invention comprises: a magnetic field generator having a coil and a core, and outputting a magnetic field to an electronic device under test; a magnetic field sensor, which detects the magnetic field; and a magnetic field control circuit, which controls a current flowing in the coil based on a detection value of the magnetic field sensor, wherein the magnetic field control circuit is input with a command value of the magnetic field generated by the magnetic field generator, the detection value of the magnetic field sensor is fed back and input to the magnetic field control circuit, the magnetic field control circuit generates an error signal according to an error between the command value and the detection value, and the magnetic field control circuit outputs a control signal to the magnetic field generator after amplifying the error with a control gain, wherein the control gain comprises: a first gain, which comprises a characteristic that the gain becomes smaller as the frequency of the error signal becomes higher; and a second gain, which comprises a characteristic that the gain becomes larger as the amplitude of the error signal becomes larger.

[0014] [5] In the magnetic field control method involved in the present invention, there are: a step of obtaining a detection value of a magnetic field sensor that detects a magnetic field through feedback control; a step of obtaining a command value of a magnetic field generated by a magnetic field generator; a step of generating an error signal according to an error between the command value and the detection value; and a step of outputting a control signal after amplifying the error with a control gain to the magnetic field generator, wherein the control gain includes: a first gain, which includes a characteristic that the higher the frequency of the error signal, the smaller the gain; and a second gain, which includes a characteristic that the larger the amplitude of the error signal, the larger the gain.

[0015] (Effects of the Invention)

[0016] According to the present invention, by sensing both the amplitude component and the frequency component of the control error, an optimum control gain is set for the speed requirement of the feedback control in a wide speed range, thereby optimizing the response characteristics of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a block diagram of a test device according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 Frame diagram of the experimental setup.

[0019] Figure 3 It is a graph showing the characteristics of gain with respect to the amplitude of the error signal.

[0020] Figure 4 : is a graph showing the gain characteristics of the control gain set by the magnetic field control circuit.

[0021] Figure 5 It is used to illustrate Figure 1 A graph showing the relationship between input variation and output variation in a test device. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described based on the drawings. Figure 1 It is a block diagram of a test device according to an embodiment of the present invention.

[0023] Figure 1 The test apparatus shown applies a magnetic field to an electronic device under test (DUT) 10 and tests (inspects) whether the DUT operates properly in this state. The DUT 10 is an object tested by the test apparatus according to this embodiment, and is a sensor such as a current sensor or a magnetic sensor.

[0024] like Figure 1 As shown, the test device 100 includes a socket 20, a magnetic field generator 30, a magnetic field sensor 40, a controller 50, and a magnetic field control circuit 60. The socket 20 is in contact with the DUT 10 and electrically connected, and holds the DUT 10. A pin for contacting the DUT 10 is provided on the top surface of the socket 20. The socket 20 has a signal line electrically connected to the pin. The socket 20 is connected to the controller 50 via a cable not shown. When the DUT 10 is connected to the socket 20, an electrical signal from the controller 50 is given to the DUT 10 via the socket 20, and the DUT 10 is tested based on the signal output from the DUT 10.

[0025] The magnetic field generator 30 is an electromagnet and has a core 31, a main coil 32, and a correction coil 33. The core 31 is a component for enhancing the magnetic flux generated by the main coil 32 and the correction coil 33 so that a closed loop (magnetic path) formed by the magnetic flux passes through the DUT 10.

[0026] The core 31 includes a main body 311 on which a main coil 32 and a correction coil 33 are wound, and an extension 312 extending from the main body 311 toward the DUT 10. The main body 311 and the extension 312 are integrated. The main body 311 is formed in a columnar shape. The extension 312 extends from both ends of the main body 311 to approach the side of the DUT 10. A magnetic field is generated from the end of the extension 312 on one side toward the end of the extension 312 on the other side, and the DUT 10 is arranged in the magnetic circuit.

[0027] The main coil 32 is wound around the main body 311 . When a current flows through the main coil 32 under the control of the controller 50 , a magnetic flux is generated, and the magnetic flux passes through a closed loop including the core 31 and the DUT 10 .

[0028] The correction coil 33 is wound around the main body 311. The number of turns of the correction coil 33 is less than the number of turns of the main coil 32. The correction coil 33 is a coil for correcting the magnetic field generated by the magnetic field generator 30. In a state where a current flows through the main coil 32 to generate a magnetic field, if a current flows through the correction coil 33, the magnetic field generated by the correction coil 33 is applied to the magnetic field generated by the main coil 32. The magnetic field generated by the correction coil 33 is smaller than the magnetic field generated by the main coil 32. By controlling the current flowing through the main coil 32, the magnetic field generated by the magnetic field generator 30 is adjusted to be larger, and by controlling the current flowing through the correction coil 33, the magnetic field generated by the magnetic field generator 30 is adjusted to be smaller.

[0029] The magnetic field sensor 40 detects the magnetic field (magnetic flux) generated by the magnetic field generator 30 . The magnetic field sensor 40 is disposed in the magnetic circuit. The detection value of the magnetic field sensor 40 is output to the magnetic field control circuit 60 .

[0030] The controller 50 controls the current flowing through the main coil 32 and the correction coil 33. The controller 50 has a computing device such as a CPU and an MPU, and a memory such as a ROM and a RAM. The controller 50 sets the magnetic field applied to the DUT based on an instruction from the outside or an operation by a user, and outputs a magnetic field command value (B) for generating the set magnetic field to the main coil 32 and the magnetic field control circuit 60. a ). Used to generate magnetic field command value (B a ) flows in the main coil 32. The controller 50 obtains the detection value (B) of the magnetic field sensor 40 via the magnetic field control circuit 60. d ). When the controller 50 changes the set magnetic field, it calculates the magnetic field command value (B) so that the detected value becomes the set magnetic field after the change. a).

[0031] The magnetic field control circuit 60 is a control circuit for controlling the magnetic field generator 30 based on the detection value of the magnetic field sensor 40. In addition, the device including the magnetic field control circuit 60 is equivalent to the control device of the present invention. The detection value (B) of the magnetic field sensor 40 is fed back to the magnetic field control circuit 60 and input. d The magnetic field command value (B) is input from the controller 50 to the magnetic field control circuit 60. a The magnetic field control circuit 60 calculates the magnetic field command value (B a ) and the detection value (B d ) to detect the magnetic field command value (B a ) and the detection value (B d ) error. The magnetic field control circuit 60 generates a signal corresponding to the detected error. Specifically, the magnetic field control circuit 60 generates a signal including a magnetic field command value (B) generated by the correction coil 33. b ) signal, so that the detection value (B d ) is consistent with the magnetic field command value. For example, when the detected value is lower than the set magnetic field (set magnetic flux), the command value (B b ) to increase the magnetic field of the magnetic field generator 30, and the calculated magnetic field command value (B b ) is output to the correction coil 33. In addition, the controller 50 and the magnetic field control circuit 60 control the main coil 32 and the correction coil 33 through current control or voltage control.

[0032] Next, refer to Figure 2 The system control in the test device 100 is described. The system control in the test device 100 includes a feedforward element and a feedback element. The system control includes a computing unit 61, control elements 62 to 65, and a control object 66. The magnetic field command value (B a ) is equivalent to the reference input signal (B ref The calculation process by the calculation unit 61 and the control process by the control elements 63 to 65 described in detail below are executed by the magnetic field control circuit 60. In addition, by returning the detection value of the magnetic field sensor to the magnetic field control circuit 60, the control process including the control element 62 is executed.

[0033] The calculation unit 61 calculates the magnetic field command value (B a) and the difference (ΔV) between the command value and the detection value. The detection value is a value converted by the control element 62. The difference (ΔV) is equivalent to the error between the command value and the detection value. Then, the operator 61 outputs an error signal including the difference (ΔV) to the control elements 63 and 65. Thus, the operator 61 generates an error signal according to the error between the command value and the detection value, and outputs the error signal to the control elements 63 and 65.

[0034] The control element 62 is an element that converts the controlled variable into a signal that can be compared with a reference input signal, and corresponds to the magnetic field sensor 40. The controlled variable is the magnetic field generated by the magnetic field generator 30. The control element 62 is a feedback element and is represented by a transfer function (H(s)).

[0035] The control element 63 detects the amplitude component of the error signal (amplitude detection). The amplitude component of the error signal is a transient control error, which is represented by the peak value, integral value, average value or effective value of the error signal at each predetermined time. The control element 64 determines the gain (G) for changing the response characteristics of the control system in response to the transient control error. M ) (Gain control). The control element 64 stores the preset gain characteristics in the map. The gain characteristics set by the control element 64 are represented by Figure 3 The curve graph shown is shown. Figure 3 In the figure, the horizontal axis represents the amplitude of the error signal (D), and the vertical axis represents the gain (G M ) size. The gain (G M ) includes the error signal amplitude (D), the larger the gain (G M ) is larger. Gain (G M ) includes a characteristic that the gain increases continuously with the increase of the amplitude (D) of the error signal. Furthermore, the control element 64 sets a smaller gain (G) when the amplitude of the error signal is small. M ), when the amplitude of the error signal is large, a larger gain (G M ).in addition, Figure 3 The gain characteristic shown is only an example. M ) can also be a characteristic that increases in proportion to the amplitude (D) of the error signal. M ) can also be included in the range of a part of the amplitude. The larger the amplitude (D) of the error signal, the greater the gain (G M For example, when the amplitude (D) of the error signal is below a predetermined low-amplitude threshold, the gain (G M ) is a first specified value. When the amplitude (D) of the error signal is greater than the threshold value on the low amplitude side and less than the specified threshold value on the high amplitude side, the greater the amplitude (D) of the error signal, the greater the gain (G M) is larger, when the amplitude (D) of the error signal is larger than the threshold value on the high amplitude side, the gain (G M ) can also be a characteristic of becoming a second predetermined value (> first predetermined value). M ) may also include a characteristic that the gain changes at a certain value within a part of the amplitude. The control element 64 sets the set gain (G M ) is output to the control element 65. The control element 63 and the control element 64 are equivalent to feedforward elements.

[0036] The control element 65 generates a control signal by amplifying the error with a control gain (G(s)), and outputs the generated control signal to the control object 66. The control element 65 generates the control signal according to the following method. In addition, the control element 65 performs filtering processing on the error signal to determine the frequency component included in the error signal having an inherent frequency response characteristic. The control element 65 determines the gain (G(s)) for the determined frequency component. F ). Gain (G F ) is a gain for changing the response characteristic of the control system relative to the stable control error. The control element 65 stores the preset gain characteristic in the map. The gain (G) set by the control element 65 F ) is characterized by Figure 4 The curve graph shown is shown. Figure 4 In the figure, the horizontal axis represents the frequency (f) of the error signal, and the vertical axis represents the magnitude of the gain. Figure 4 The dashed line in the graph represents the gain (G F ) characteristics. Gain (G F ) includes the characteristic that the higher the frequency of the error signal, the smaller the gain. Figure 4 In the example of the error signal, the frequency threshold (f L ) or less, the gain (G F ) becomes the maximum gain (G F_P ), the frequency of the error signal is lower than the frequency threshold (f L ) is higher than the frequency threshold (f H ) is low, the gain (G F ) decreases in proportion to the increase in frequency.

[0037] In addition, the gain (G F ) as long as it is included in a part of the frequency range, the higher the frequency, the greater the gain (G F ) is smaller, not necessarily Figure 4 The gain (G F ) may also include a characteristic in which the gain shifts by a certain value within a part of the frequency range.

[0038] The control element 65 determines the gain (G F ) plus the gain (G M ) to determine the control gain (G M ×G F ). That is, the control gain (G M ×G F ) including gain (G M ) and gain (G F ). Figure 4 The solid line graph represents the control gain (G M ×G F ) characteristics. For example, when the amplitude of the error signal is D a In the case of M ) is determined by the size of G M1 The control element 65 controls the gain (G F ) plus the gain for the vibration component (G M1 ).exist Figure 4 In the example, if the vertical axis is set to logarithmic display, relative to the gain (G F ), in such a way that the gain becomes larger, the offset gain (G M1 ) becomes the control gain. As a result, the control gain becomes larger. M1 ) is offset by. In addition, for example, Figure 3 and Figure 4 In the example, when the amplitude of the error signal is greater than D a In the case of M ) becomes greater than G M1 , so the shift amount of the control gain also becomes larger.

[0039] Control element 65 controls the gain (G M ×G F ) amplifies the error signal. The control element 65 converts the command value included in the amplified error signal (the command value amplified by the control gain) into a control signal that can be controlled by the control object 66, and outputs it to the control object 66. The control object 66 corresponding to the magnetic field generator 30 generates a magnetic field based on the control signal.

[0040] Next, refer to Figure 2 This paper explains the variable factors (noise factors) that affect system control and the responsiveness required to various changes. Figure 2 In, V nG 、V nH 、V nR Indicates the variation (noise) applied to the system control. V nGV represents a change in the control system, for example, a change caused by an external factor of the test device 100, such as vibration applied to the test device 100 or a change in the magnetic properties of the core. In the following description, a change factor requiring a high response speed in order to suppress the change is referred to as V. nG (High speed), the variable factor that requires a low response speed to suppress the fluctuation is set to V nR (Low speed). In addition, in order to suppress the fluctuation, the required ratio fluctuation factor (V nG ) is low and has a lower variation factor (V nR ) The variable factor of high response speed is set to V nH However, in order to suppress V nG 、V nH 、V nR The magnitude relationship of the required response speed varies appropriately according to the setting conditions, operating conditions, or environment of the system control. nG 、V nH 、V nR ) is not limited to the order of "high speed, medium speed, low speed" as in the following example, but may also be "high speed, low speed, medium speed", "medium speed, high speed, low speed", or "low speed, medium speed, high speed". In the system control of this embodiment, in order to increase the control gain and speed up the feedback speed of the loop control, the gain of the feedforward (G M ), suppressing the change. On the other hand, if the control gain is small, a voltage V nG If the output value of the control object 66 changes due to the change of the factor, it takes time to restore the output value of the control object 66 to the command value of the reference input signal. nG The change of the factor is detected based on the amplitude component of the error signal, and the gain is increased by the gain control of the control element 64. Moreover, during the test, when the setting of the magnetic field is changed according to the command from the outside, the magnetic field generated by the magnetic field generator 30 can quickly follow the setting change of the magnetic field, and the setting speed of the magnetic field can also be improved.

[0041] V nR Indicates the noise included in the reference input signal, and indicates the fluctuation caused by the internal noise of the computing unit that calculates the command value (reference value). nR and other variable factors (V nH 、V nG ) requires a lower response speed (low speed). When the command value changes due to internal reasons such as internal noise of the operator, the command value changes at a high speed. Therefore, if the gain of the feedforward (G M), the control gain is reduced to slow down the feedback speed of the loop control, and the change of the command value is absorbed. On the other hand, when the feedback speed of the loop control is fast, the gain setting changes in accordance with the change of the command value, and the command of the control signal is unstable. That is, in this embodiment, when the command value of the error signal changes due to internal factors, the control gain is set in a manner to absorb the change.

[0042] V nH V represents the noise included in the detection value of the magnetic field sensor 40, for example, represents the fluctuation caused by the noise inside the sensor. nH and other variable factors (V nG ) requires a lower response speed (medium speed). Therefore, similarly to the low speed, the system control of this embodiment reduces the gain (G M ), reducing the control gain, slowing down the feedback speed of the loop control, thereby absorbing the changes in the detection value of the magnetic field sensor 40.

[0043] Thus, the gain (G) set in the system control of this embodiment M ) is set according to the command value responsiveness (low speed) required for the command value of the reference value signal, the output value responsiveness (high speed) required for the output change of the magnetic field generator 30, and the detection value responsiveness (medium speed) required for the change of the detection value of the magnetic field sensor 40. In this way, it is possible to achieve both high-speed control that quickly follows the setting change of the magnetic field and internal noise suppression that absorbs the change of the command value / detection value caused by the internal noise.

[0044] Figure 5 It is a diagram for explaining input changes and output changes to the system control in the test device 100 . Figure 5 (a) indicates input change. Figure 5 The input variation shown in (a) includes noise of external factors and noise of internal factors. The external factor is represented by arrow P. Due to the influence of the noise of the external factor, the command value included in the reference signal changes in a pulse shape. The input variation other than arrow P is the noise of the internal factor. Figure 5 The graph shown in (b) of FIG. 1 shows the output change when only low-speed control is performed in the high-speed control and low-speed control. High-speed control means loop control with high response speed by increasing control gain. In the system control in the test device 100, the gain (G M ) is equivalent to high-speed control. Low-speed control means loop control that reduces the control gain and slows down the response speed. In the system control in the test device 100, the feedforward gain (G M ) of the control and / or feedback gain (G F ) is equivalent to low-speed control. Figure 5As shown in (b), when only low-speed control is performed, the fluctuation caused by the noise of the internal factor becomes smaller, but the fluctuation caused by the noise of the external factor cannot be fully suppressed (see arrow Q).

[0045] Figure 5 The graph shown in (c) shows the output variation when only high-speed control is performed and when only high-speed control is performed. When only high-speed control is performed, the variation caused by noise of external factors becomes smaller, but the variation caused by noise of internal factors cannot be suppressed.

[0046] Figure 5 The graph shown in (d) shows output changes when both high-speed control and low-speed control are performed, and shows output changes of the system control in the test device 100. When both high-speed control and low-speed control are performed, both changes caused by noise of internal factors and changes caused by noise of external factors can be suppressed.

[0047] As described above, the control device of the magnetic field generator 30 according to the present embodiment includes a magnetic field control circuit 60 for controlling the magnetic field generator 30 based on the detection value of the magnetic field sensor 40. The magnetic field control circuit 60 receives an instruction value of the magnetic field generated by the magnetic field generator 30, feeds back and receives the detection value of the magnetic field sensor 40, generates an error signal according to the error between the instruction value and the detection value, and outputs a control signal after amplifying the error with a control gain to the magnetic field generator 30. The control gain includes a gain (G) having a characteristic that the higher the frequency of the error signal, the smaller the gain. F : Equivalent to the “first gain” of the present invention); and a gain (G M : Equivalent to the "second gain" of the present invention). Thus, it is possible to achieve both high-speed control that quickly follows the setting change of the magnetic field and internal noise suppression that absorbs the fluctuation of the command value / detection value caused by the internal noise, thereby optimizing the response characteristics of the control system.

[0048] In the control device for the magnetic field generator 30 according to the present embodiment, the gain (G M ) is set according to the command value responsiveness required for the command value of the reference value signal, the output value responsiveness required for the output change of the magnetic field generator 30, and the detection value responsiveness required for the change of the detection value of the magnetic field sensor 40. In this way, it is possible to achieve both high-speed control that quickly follows the setting change of the magnetic field and internal noise suppression that absorbs the change of the command value / detection value caused by the internal noise, thereby optimizing the response characteristics of the control system.

[0049] In the control device for the magnetic field generator 30 according to the present embodiment, the gain (G M) includes a characteristic that the gain increases continuously with the increase in the amplitude of the error signal. For example, in a system control different from the present embodiment, there is also a control in which the gain is switched by a switch, but the gain characteristic in such a control cannot maintain the continuity of the output with respect to the input change. On the other hand, in the present embodiment, the gain characteristic changes smoothly, so the continuity of the output can be maintained with respect to the input change.

[0050] In addition, the test device 100 according to the present embodiment includes: a magnetic field generator 30 having a coil and a core, which outputs a magnetic field to the electronic device under test (DUT); and a magnetic field sensor 40, which detects the magnetic field. Thus, it is possible to achieve both high-speed control that quickly follows the setting change of the magnetic field and internal noise suppression that absorbs the fluctuation of the command value / detection value caused by the internal noise, thereby optimizing the response characteristics of the control system.

[0051] In addition, the magnetic field control method involved in this embodiment includes: a step of obtaining the detection value of the magnetic field sensor 40 through feedback control; a step of obtaining the command value of the magnetic field generated by the magnetic field generator 30; a step of generating an error signal according to the error between the command value and the detection value; and a step of outputting the control signal after amplifying the error with the control gain to the magnetic field generator. In addition, the control gain includes: a gain (G) including a characteristic that the higher the frequency of the error signal, the smaller the gain F ); and a gain (G M ). Thus, it is possible to achieve both high-speed control that quickly follows the setting change of the magnetic field and internal noise suppression that absorbs the change of the command value / detection value caused by the internal noise, thereby optimizing the response characteristics of the control system.

[0052] In addition, the above-described embodiments are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above-described embodiments also includes all design changes or equivalents belonging to the technical scope of the present invention.

[0053] (Description of the label)

[0054] 10 Device Under Test (DUT)

[0055] 20 sockets

[0056] 30 Magnetic Field Generator

[0057] 31 cores

[0058] 32 Main coil

[0059] 33. Correction coil

[0060] 40 Magnetic Field Sensor

[0061] 50 Controller

[0062] 60 Magnetic field control circuit

[0063] 100 Test device.

Claims

1. A control device for a magnetic field generator, which controls a magnetic field generated by the magnetic field generator, wherein the control device for the magnetic field generator is characterized in that: The control device includes a magnetic field control circuit that controls the magnetic field generator based on a detection value of a magnetic field sensor that detects the magnetic field. The magnetic field control circuit receives as input a command value of the magnetic field generated by the magnetic field generator. The magnetic field control circuit is fed back and input with the detection value of the magnetic field sensor, The magnetic field control circuit generates an error signal according to the error between the command value and the detection value. The magnetic field control circuit outputs a control signal after amplifying the error with a control gain to the magnetic field generator. The control gain includes a first gain (G F ) and the second gain (G M ) of the control gain (G M ×G F ), The first gain (G F ) includes the characteristic that the higher the frequency of the error signal, the smaller the gain, The second gain (G M ) includes the characteristic that the larger the amplitude of the error signal, the larger the gain.

2. The control device for the magnetic field generator according to claim 1, characterized in that: The second gain (G M ) is set according to the command value responsiveness required to the change of the command value, the output value responsiveness required to the output change of the magnetic field generator, and the detection value responsiveness required to the change of the detection value of the magnetic field sensor.

3. The control device for the magnetic field generator according to claim 1 or 2, characterized in that: The second gain (G M ) includes the characteristic that the gain increases continuously with respect to the increase of the amplitude.

4. A test device for testing an electronic device under test, wherein the test device is characterized in that: The test device includes: A magnetic field generator, which has a coil and a core and outputs a magnetic field to the electronic device under test; a magnetic field sensor that detects the magnetic field; and a magnetic field control circuit that controls a current flowing in the coil based on a detection value of the magnetic field sensor, The magnetic field control circuit receives as input a command value of the magnetic field generated by the magnetic field generator. The magnetic field control circuit is fed back and input with the detection value of the magnetic field sensor, The magnetic field control circuit generates an error signal according to the error between the command value and the detection value. The magnetic field control circuit outputs a control signal after amplifying the error with a control gain to the magnetic field generator. The control gain includes a first gain (G F ) and the second gain (G M ) of the control gain (G M ×G F ), The first gain (G F ) includes the characteristic that the higher the frequency of the error signal, the smaller the gain, The second gain (G M ) includes the characteristic that the larger the amplitude of the error signal, the larger the gain.

5. A magnetic field control method, which is a magnetic field control method for controlling a magnetic field generated by a magnetic field generator, wherein the magnetic field control method is characterized in that: The magnetic field control method includes: A step of acquiring a detection value of a magnetic field sensor that detects the magnetic field through feedback control; A step of obtaining a command value of a magnetic field generated by the magnetic field generator; A step of generating an error signal according to an error between the command value and the detection value; as well as The step of outputting a control signal obtained by amplifying the error by a control gain to the magnetic field generator, The control gain includes a first gain (G F ) and the second gain (G M ) of the control gain (G M ×G F ), The first gain (G F ) includes the characteristic that the higher the frequency of the error signal, the smaller the gain, The second gain (G M ) includes the characteristic that the larger the amplitude of the error signal, the larger the gain.

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