Motor Control Systems

Abstract

To suppress increase in cost of a motor control IC due to measurement of the frequency characteristics of a control loop.SOLUTION: A motor control system includes: a motor control device (10) that is constituted of a semiconductor integrated circuit having a memory, and forms a control loop for a motor (40) to control driving of the motor; and external debugging devices (20, 30) that are externally connected to the motor control device and can access the memory in the motor control device. The external debugging device is provided with: a disturbance signal superimposing unit (22) that generates a disturbance signal (ωN) for the control loop and superimposes the disturbance signal on a signal in the control loop; and a frequency characteristic deriving unit (32) that derives frequency characteristics of the control loop on the basis of a signal generated in the control loop by superimposition.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to motor control systems. [Background technology]

[0002] There is a method for measuring the frequency characteristics of a motor's control loop in order to evaluate the stability of motor control. The measured frequency characteristics are generally expressed as a Bode plot. In order to draw a Bode plot, expensive measuring equipment such as a Frequency Response Analyzer (hereinafter referred to as FRA) is often used.

[0003] On the other hand, there are also motor control devices that are provided with a function for measuring frequency characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-304219 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, equipping a motor control device with a function for measuring frequency characteristics puts strain on the resources (memory capacity, etc.) of the motor control device, leading to an increase in the cost of the motor control device product itself.

[0006] An object of the present disclosure is to provide a motor control system that contributes to suppressing increases in costs associated with deriving frequency characteristics. [Means for solving the problem]

[0007] The motor control system according to the present disclosure is a first configuration, comprising: a motor control device formed of a semiconductor integrated circuit having a memory, which forms a control loop for a motor to control driving of the motor; and an external debug device externally connected to the motor control device and capable of accessing the memory, wherein the external debug device is provided with a disturbance signal superposition unit that generates a disturbance signal for the control loop and superimposes the disturbance signal on a signal in the control loop, and a frequency characteristic derivation unit that derives the frequency characteristics of the control loop based on the signal generated in the control loop by the superposition.

[0008] In the motor control system according to the first configuration, the external debug device may be configured to include a debugger including the external signal output unit and a calculation unit including the frequency characteristic derivation unit, the debugger being externally connected to the motor control device and disposed between the calculation unit and the motor control device, and superimposing the disturbance signal under the instruction of the calculation unit, and the signal generated within the control loop by the superposition may be transmitted from the motor control device to the calculation unit via the debugger (second configuration).

[0009] In the motor control system according to the first or second configuration, the external debugging device may be further provided with a display unit that displays a Bode plot as a diagram representing the frequency characteristic (third configuration).

[0010] In the motor control system according to any one of the first to third configurations, when the disturbance signal is superimposed on the motor control device, starting from a state in which the motor control device controls the drive of the motor by itself without superimposing the disturbance signal, the motor control device may continue to control the drive of the motor while the frequency characteristic derivation unit derives the frequency characteristic (fourth configuration).

[0011] In the motor control system according to any of the above first to fourth configurations, the external debug device may be capable of monitoring other signals within the motor control device while performing the process of deriving the frequency characteristic through superimposition of the disturbance signal, and the other signals may be different signals from the signals referenced by the frequency characteristic derivation unit to derive the frequency characteristic (fifth configuration).

[0012] In the motor control system according to any one of the first to fifth configurations above, the external debugging device may be configured (sixth configuration) to further include a transfer function estimation unit that estimates a transfer function of the control loop based on the derived frequency characteristic.

[0013] In the motor control system according to the sixth configuration, the external debug device may be further configured (seventh configuration) to include a gain adjustment unit that adjusts the gain of the control loop based on the estimated transfer function.

[0014] In the motor control system according to any one of the above first to seventh configurations, the motor control device may perform speed control in the control loop to make the rotational speed of the motor match or approach a speed command, and the external signal output unit may be configured to superimpose the disturbance signal on the speed command (eighth configuration).

[0015] In the motor control system according to any one of the above first to eighth configurations, the disturbance signal superimposing unit may be configured (ninth configuration) to generate digital noise including signal components of each frequency within a predetermined band as the disturbance signal. Effect of the Invention

[0016] According to the present disclosure, it is possible to provide a motor control system that contributes to suppressing cost increases associated with deriving frequency characteristics. [Brief description of the drawings]

[0017] [Figure 1]1 is an overall configuration block diagram of a motor control system according to a first embodiment of the present disclosure. [Diagram 2] 1 is an overall configuration diagram of a motor drive system according to a first embodiment of the present disclosure. [Diagram 3] 1 is a schematic configuration block diagram of a motor control IC according to a first embodiment of the present disclosure. [Figure 4] 1A to 1C are diagrams illustrating the operation of read access and write access in a debugging operation according to the first embodiment of the present disclosure. [Diagram 5] 1 is a functional block diagram of a motor drive system according to a first embodiment of the present disclosure. FIG. [Figure 6] FIG. 4 is a diagram showing a display example of a derived Bode plot according to the first embodiment of the present disclosure. [Figure 7] FIG. 2 is a block diagram of functions implemented in a host computer according to the first embodiment of the present disclosure. [Figure 8] FIG. 11 is a functional block diagram of a motor drive system according to a second embodiment of the present disclosure. [Figure 9] FIG. 11 is a schematic configuration diagram of a power supply device according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, examples of embodiments of the present disclosure will be specifically described with reference to the drawings. In each of the drawings, the same parts are given the same reference numerals, and duplicated descriptions of the same parts are generally omitted. In this specification, for the sake of simplicity, a symbol or code referring to information, signal, physical quantity, element, or part may be written, and the names of the information, signal, physical quantity, element, or part corresponding to the symbol or code may be omitted or abbreviated.

[0019] <<First embodiment>> A first embodiment of the present disclosure will be described. Fig. 1 shows an overall configuration block diagram of a motor control system according to the first embodiment. The motor control system according to the first embodiment includes a motor control IC 10 that functions as a motor control device or includes a motor control device, a debugger 20, and a host computer 30 (hereinafter, may be referred to as a host PC 30) that is an example of a computing device. IC is an abbreviation for integrated circuit. Fig. 2 shows an overall configuration diagram of a motor drive system including the motor control system according to the first embodiment and a motor 40.

[0020] The motor control IC 10 is an electronic component formed by enclosing and sealing a semiconductor chip on which a semiconductor integrated circuit is formed in a housing (package) made of sealing resin. A plurality of external terminals are exposed on the housing of the motor control IC 10. As shown in FIG. 2, the motor control IC 10 is mounted on a substrate SUB, and each external terminal is electrically connected to a corresponding wiring pattern (not shown) on the substrate SUB. The motor control IC 10 inputs and outputs signals between circuits and devices outside the motor control IC 10 through the external terminals. Note that the number of external terminals of the motor control IC 10 and the appearance of the motor control IC 10 shown in FIG. 2 are merely examples. Also, many electronic components and circuits other than the motor control IC 10 may be mounted on the substrate SUB, but these are not shown in FIG. 2.

[0021] 3 shows a schematic block diagram of the motor control IC 10. The semiconductor integrated circuits in the motor control IC 10 form a CPU (Central Processing Unit) 11, memory 12, and debug control unit 14. Here, for the purpose of explaining the functions, the CPU 11, memory 12, and debug control unit 14 are shown separately, but the motor control IC 10 may form an LSI (Large Scale Integration) that integrates these.

[0022] The CPU 11 is connected to the memory 12 via the bus 13 and can access the memory 12 via the bus 13. Access to the memory 12 refers to writing data to the memory 12 (i.e., writing data to the memory 12) or reading data from the memory 12 (i.e., reading data stored in the memory 12). The memory 12 includes one or more read only memories (ROMs), one or more random access memories (RAMs), and one or more peripherals that are one or more peripheral circuits. Note that registers (not shown) provided in the CPU 11 may also be considered to be included in the memory 12. However, the CPU 11 can access the registers without going through the bus 13.

[0023] The CPU 11 controls the driving of the motor 40 by executing a motor control program held in the motor control IC 10. The motor control program is stored in a ROM in the memory 12, or in a program ROM (not shown) provided separately in the motor control IC 10.

[0024] The debug control unit 14 is a block that is not involved in the actual drive control of the motor 40, and is composed of a small-scale microcomputer, etc. The debug control unit 14 cooperates with the debugger 20 and the host PC 30 to contribute to the debugging work described below.

[0025] 2, a connector 51 is mounted on the board SUB, and the connector 51 is connected to the motor 40 through a wire 52. The motor control IC 10 operates to supply the necessary current to the motor 40 through the connector 51 and the wire 52, and the supply of current drives the motor 40 (torque is generated in the motor 40, causing the motor 40 to rotate). A connector 53 is also mounted on the board SUB. Connectors 55 and 56 are mounted on the debugger 20, and a connector 58 is mounted on the host PC 30. The connectors 53 and 55 are connected by a wire 54, and the connectors 56 and 58 are connected by a wire 57.

[0026] The debugger 20 and the board SUB can be freely connected or disconnected by the wiring 54 (in other words, the debugger 20 and the motor control IC 10 can be freely connected or disconnected by the wiring 54). When the debugger 20 and the board SUB are connected by the wiring 54, the debugger 20 and the motor control IC 10 on the board SUB are connected, and the debugger 20 and the motor control IC 10 can perform two-way communication of any signal through the connector 53, the wiring 54, and the connector 55. When the debugger 20 and the board SUB are not connected by the wiring 54, the debugger 20 and the motor control IC 10 on the board SUB are not connected, and the two-way communication is not possible. Signals are exchanged between the debugger 20 and the motor control IC 10 via the debug control unit 14.

[0027] The debugger 20 and the host PC 30 can be freely connected or disconnected by the wire 57. When the debugger 20 and the host PC 30 are connected by the wire 57, the debugger 20 and the host PC 30 can perform two-way communication of any signal through the connector 56, the wire 57, and the connector 58. When the debugger 20 and the host PC 30 are not connected by the wire 57, the two-way communication is not possible.

[0028] Unless otherwise specified below, it is assumed that the debugger 20 and the board SUB are connected by a wire 54, and that the debugger 20 and the host PC 30 are connected by a wire 57. In this embodiment, a signal representing any information (control amount, state amount, physical amount, etc.) or information indicated by the signal may be referred to as data.

[0029] Debug software 31 (see FIG. 1) is executed in the host PC 30. A user of the motor drive system (hereinafter simply referred to as the user) can debug a program executed by the CPU 11 by operating the host PC 30 on which the debug software 31 is executed. In the debugging operation, the debugger 20 and the host PC 30 can access the memory 12. In other words, the debugger 20 and the host PC 30 are externally connected to the motor control IC 10 and function as an external debugging device that can access the memory 12.

[0030] That is, for example, in a debugging operation, the user may perform an operation OP to instruct the host PC 30 to read data, as shown in FIG. READ The host PC 30 can input the operation OP READ When you receive the operation OP READ A request signal REQ READ The debugger 20 sends a request signal REQ READ When the request signal REQ READ Read command COM according to READ is sent to the motor control IC 10. Operation OP READ A variable name of the program or a read target address in the memory 12 is specified by a request signal REQ READ and read command COM READ The read command COM contains the information of the address to be read. READ The debug control unit 14 receives the read command COM READ When the data is received, the read target address in the memory 12 is accessed to read the data in the read target address, and the read data is stored as data D READ The data is sent to the debugger 20 as data D. READ is sent from the debugger 20 to the host PC 30, and the data D READ is obtained. Note that the operation OP READAs a method for specifying a program variable name or a read target address in memory 12, it is also possible to use information generated when converting (compiling) firmware written in C language into machine language.

[0031] Also, for example, in a debugging operation, the user may perform an operation OP to instruct the host PC 30 to write data, as shown in FIG. WRITE The host PC 30 can input the operation OP WRITE When you receive the operation OP WRITE A request signal REQ WRITE The debugger 20 sends a request signal REQ WRITE When the request signal REQ WRITE Write command COM according to WRITE is sent to the motor control IC 10. Operation OP WRITE The program variable name or the write target address and write data (corresponding to the data to be written to the write target address) in the memory 12 are specified by the request signal REQ WRITE and write command COM WRITE The write command COM contains the write target address information and write data information. WRITE The write command COM is received by the debug control unit 14. WRITE When the operation OP is received, the write address in the memory 12 is accessed and the write data is written to the write address. WRITE As a method for specifying a program variable name or a write target address in memory 12, it is also possible to use information generated when converting (compiling) firmware written in C language into machine language.

[0032] Although the access to the memory 12 has been described above, various processes can be realized in the debugging operation other than the access to the memory 12. For example, in the debugging operation, the user can operate the host PC 30 to break the program being executed by the CPU 11, or to refer to or change the state of the state machine in the CPU 11.

[0033] Fig. 5 shows a functional block diagram of the motor drive system according to the first embodiment. The motor control IC 10 includes a motor control unit 110 for controlling the drive of the motor 40. A driver 50 is provided between the motor control IC 10 and the motor 40. However, a modification in which the driver 50 is built into the motor control IC 10 is also possible.

[0034] The motor control unit 110 includes, as functional blocks, a speed detection unit 111, a speed command supply unit 112, a subtractor (an arithmetic unit) 113, a current detection unit 114, a speed control unit 115, a subtractor 116, and a current control unit 117. Each of these functional blocks may be realized by the CPU 11 executing a motor control program.

[0035] The motor 40 is composed of a stator provided with an armature winding, and a rotor that is rotated by supplying a current to the armature winding. In this embodiment, the supply of a current to the motor 40 specifically means the supply of a current to the armature winding of the motor 40, and the rotation of the motor 40 specifically means the rotation of the rotor. The rotation angle of the rotor from a predetermined reference state of the rotor is referred to as the rotor position θ. A position detector (not shown) for detecting the rotor position θ is attached to the motor 40. The position detector is composed of, for example, a rotary encoder or a resolver. The speed detection unit 111 detects the rotation speed ω of the motor 40 based on the detection result of the position detector (i.e., by differentiating the detected rotor position θ, for example). The rotation speed ω represents the rotation speed of the rotor in electrical angle.

[0036] The speed command supply unit 112 supplies a speed command ω representing a target value of the rotation speed ω to the subtractor 113. *The signal of the speed command ω * is determined based on a signal provided to the motor control IC 10 from a higher-level circuit (not shown) provided outside the motor control IC 10. However, the speed command ω * In applications where the speed command ω is fixed, the motor control IC 10 generates the speed command ω * may be set.

[0037] The subtractor 113 subtracts the signal of the rotation speed ω detected by the speed detector 111 from the speed command ω supplied from the speed command supply unit 112. * However, when the speed error Δω is calculated, the debugger 20 outputs a disturbance signal ω N may be input to the subtractor 113 (i.e., the speed command ω * Disturbance signal ω N The speed error Δω is calculated as “Δω = ω * -ω+ω N In FIG. 5, the disturbance signal ω N is input to the subtractor 113. The disturbance signal ω N In a situation where "ω" is not input to the subtractor 113, N =0”, so “Δω=ω * -ω”.

[0038] The current detection unit 114 detects the motor current i, which is a current supplied from the driver 50 to the armature winding of the motor 40 (i.e., detects the value of the motor current i). For example, the current detection unit 114 can detect the motor current i using a current sensor provided between the driver 50 and the motor 40. A signal of the detected motor current i is sent to the subtractor 116.

[0039] The speed control unit 115 calculates a current command i representing a target value of the motor current i based on the speed error Δω. * and the current command i * The speed control unit 115 outputs the signal i to the subtractor 116. At this time, the speed control unit 115 uses proportional-integral control to adjust the current command i so that the speed error Δω converges to zero. * Generate.

[0040] The subtractor 116 subtracts the signal of the motor current i detected by the current detection unit 114 from the current command i supplied from the speed control unit 115. * The current error Δi is calculated based on the signal of the current sensor. The current error Δi is expressed as “Δi=i * -i”.

[0041] The current control unit 117 supplies a current to the motor 40 by controlling the driver 50 based on the current error Δi. At this time, the current control unit 117 controls the driver 50 using proportional-integral control so that the current error Δi converges to zero. More specifically, the current control unit 117 generates a drive control signal for the driver 50 based on the current error Δi so that the current error Δi converges to zero, and provides the drive control signal to the driver 50. The driver 50 supplies a current corresponding to the drive control signal to the armature winding of the motor 40. The driver 50 is composed of, for example, an inverter circuit that generates a pulse-width-modulated rectangular wave voltage from a predetermined DC voltage, and supplies the motor current i to the motor 40 by providing the rectangular wave voltage to the armature winding.

[0042] The type of motor 40, including the number of phases, is arbitrary, but typically, for example, the motor 40 may be a three-phase permanent magnet synchronous motor including a rotor provided with a permanent magnet and a stator provided with U-phase, V-phase, and W-phase armature windings. In this case, in a rotating coordinate system that rotates at the same speed as the rotational speed of the magnetic flux created by the permanent magnet of the rotor, the d-axis is taken as the direction of the magnetic flux created by the permanent magnet, and the q-axis is taken as the axis perpendicular to the d-axis. In this case, the angle (phase) of the d-axis as viewed from a predetermined fixed axis (for example, the fixed axis of the U-phase armature winding) corresponds to the rotational angle of the motor 40 (i.e., the rotor position θ), and the rotational speed ω of the motor 40 corresponds to the rotational speed of the d-axis (angular speed in electrical angle).

[0043] In addition, when the motor 40 is a three-phase permanent magnet synchronous motor, the driver 50 is configured with a three-phase inverter circuit that supplies current to the armature windings of each phase, and the motor current i, the current command i *and the current error Δi are vector quantities. When the motor 40 is vector-controlled, for example, the d-axis component (i d ) and the q-axis component (i q ) and send the determined d-axis component and q-axis component to the subtractor 116 as a signal of the motor current i. Then, the speed control unit 115 calculates the target values ​​(i d * , i q * ) to the current command i * The current control unit 117 can include the d-axis component (i d ), q-axis component (i q ) are the target values ​​(i d * , i q * ) the driver 50 may be controlled to match the

[0044] In the motor drive system, a frequency characteristic measurement process can be executed by connecting an external debugging device consisting of a debugger 20 and a host PC 30 to the motor control IC 10. In the frequency characteristic measurement process, the frequency characteristic of a control loop formed by the motor control unit 110 is measured. The frequency characteristic measurement process is realized using a disturbance signal superimposing unit 22 and a frequency characteristic derivation unit 32. The disturbance signal superimposing unit 22 is provided in the debugger 20, and the frequency characteristic derivation unit 32 is provided in the host PC 30. The function of the frequency characteristic derivation unit 32 is realized by executing debug software 31 (see FIG. 1) in the host PC 30. In addition, the host PC 30 is provided with a display unit 33 formed of a liquid crystal display panel or the like.

[0045] When a user inputs a predetermined frequency characteristic measurement instruction operation to the host PC 30, a request signal 71 is transmitted from the host PC 30 (for example, from the frequency characteristic derivation unit 32) to the debugger 20. When the debugger 20 receives the request signal 71, the disturbance signal superimposition unit 22 superimposes the disturbance signal ω N Generate the disturbance signal ω N The disturbance signal ω N is introduced into the control loop of the motor control unit 110 through the debug control unit 14 (see FIG. 3), and specifically becomes an input signal to the adder 113.

[0046] Disturbance signal ω N is a noise that includes signal components of each frequency in a predetermined measurement band. N By sweeping the frequency of ω, noise containing signal components of each frequency within the measurement band is generated. * , rotation speed ω, speed error Δω, current command i * The signals of the state quantities or control quantities represented by the motor current i and the current error Δi are digital signals. N is generated as a digital disturbance signal with the dimension of angular velocity. N The type of noise as the disturbance signal ω N The noise as the request signal 71 may be, for example, white noise or colored noise (pink noise, gray noise, etc.). Any known method can be used to generate a digital disturbance signal (noise). N The characteristics of the disturbance signal ω are specified (such as the measurement band and signal amplitude). N is generated.

[0047] As described above, the subtractor 113 calculates "Δω=ω * -ω+ω N In practice, for example, the first calculation value (ω * -ω) is calculated, and then the second calculation value (ω* -ω+ω N In the frequency characteristic measurement process, the debug control unit 14 (see FIG. 3) calculates a speed error Δω represented by the first calculation value (ω * -ω) and the second calculation value (ω * -ω+ω N ) is read from the subtractor 113, and the first calculation value (ω * -ω) and the second calculation value (ω * -ω+ω N ) to the debugger 20. In practice, for example, the first and second calculation values ​​are stored in a specific storage area in the memory 12 (which may be a register of the CPU 11), and the debug control unit 14 obtains the first and second calculation values ​​by reading the stored data in the specific storage area. N During the period in which the speed command ω * The value of is fixed at a constant value.

[0048] The result signal 72 is transferred from the debugger 20 to the host PC 30, and the frequency characteristic deriving unit 32 derives the frequency characteristic of the control loop of the motor control unit 110 based on the result signal 72. The frequency characteristic derived here is the frequency characteristic of the speed control loop for the motor 40 (hereinafter, simply referred to as the frequency characteristic in this embodiment). The speed control loop is a loop in which a speed command ω * The control loop (feedback control system) has a speed command ω as an input and a rotation speed ω as an output, and is formed by including components referenced by the reference numerals 111, 113, 114, 115, 116, 117, 50, and 40. * Speed ​​control is realized to make the rotation speed ω coincident with or approach the disturbance signal ω. N is input to the subtractor 113, the disturbance signal ω N is the speed command ω * Since the speed control loop is superimposed on the speed command (ω * +ω N ) as input and the rotation speed ω as output, and the superimposed speed command (ω * +ω N) to make the rotation speed ω match or approach that of the

[0049] In the host PC 30, the frequency characteristic derivation unit 32 creates a Bode diagram as a diagram showing the derived frequency characteristic, and displays the created Bode diagram on the display unit 33 as shown in FIG. 6. The Bode diagram is composed of a gain diagram showing the frequency dependency of the gain of the control loop, and a phase diagram showing the frequency dependency of the phase of the control loop. The control loop of interest in this embodiment is a speed control loop that performs speed control, and for convenience, the gain and phase in the speed control loop are referred to by the symbols G_ω and P_ω, respectively. The gain G_ω and phase P_ω are determined by the speed command ω * The gain and phase of the transfer function with the speed command ω as the input and the rotation speed ω as the output. * represents the ratio of the amplitude of the rotation speed ω to the amplitude of the speed command ω. * The speed command ω based on the signal * represents the phase difference between the signal of the rotation speed ω and the signal of the rotation speed ω.

[0050] As described above, expensive measuring instruments such as FRA are often used to draw Bode diagrams. However, FRA is expensive and not easy to use. Furthermore, many FRAs perform measurements using analog signals, and in order to measure frequency characteristics in digital control, unnecessary measures for normal operation, such as generating an analog signal dedicated to measurement, are required. On the other hand, in motor control devices that perform digital control, it is also considered to provide a frequency characteristic measuring function inside. However, by installing a frequency characteristic measuring function that is not necessary for the original motor control, the resources (memory capacity, etc.) of the motor control device are strained, leading to an increase in the cost of the motor control device itself. In consideration of these, in this embodiment, the disturbance signal superimposing unit 22 and the frequency characteristic derivation unit 32 that handle the frequency characteristic measurement process are provided in the external debugging device (debugger 20 and host PC 30) of the motor control IC 10. As a result, an expensive measuring instrument such as FRA is no longer necessary, and since the frequency characteristic measuring function is concentrated on the external debugging device (20, 30) side, the increase in cost of the motor control IC 10 is suppressed. The motor control IC 10 only needs to perform normal control for driving the motor 40.

[0051] Hereinafter, the state in which the external debug device (20, 30) and the motor control IC 10 are connected will be referred to as the connected state of the external debug device, and the state in which the external debug device (20, 30) and the motor control IC 10 are not connected will be referred to as the disconnected state of the external debug device. In the connected state of the external debug device, the motor control IC 10 and the debugger 20 are connected through a wire 54, and the debugger 20 and the host PC 30 are connected through a wire 57. As described above, the disturbance signal ω N In the disconnected state of the external debugging device, the motor control IC 10 and the debugger 20 are not connected via the wiring 54, or the debugger 20 and the host PC 30 are not connected via the wiring 57, and at least the disturbance signal ω N No input is made to the motor control IC 10.

[0052] In the motor drive system according to this embodiment, the frequency characteristics can be measured by connecting the external debugging device (20, 30) to the motor control IC 10 at any timing while the motor 40 is being driven. Consider this from the start of a state in which the external debugging device is not connected. In a state in which the external debugging device is not connected, the motor control unit 110 detects "ω N = 0”, the driving of the motor 40 is controlled, that is, the motor control IC 10 (motor control unit 110) controls the driving of the motor 40 independently of the external debugging device (20, 30). Now, in the state in which the motor 40 is being driven and controlled, it is assumed that the state transitions from the non-connection state of the external debugging device to the connection state of the external debugging device. In the connection state of the external debugging device after the transition, the disturbance signal ω N 5, the motor control unit 110 can perform the above-mentioned frequency characteristic measurement process involving the superposition of ω. This makes it possible to measure and derive the frequency characteristic without stopping the drive control of the motor 40. * And (ω * +ω N ) is the only difference.

[0053] In this way, the disturbance signal ω N Starting from a state where the motor control IC 10 (motor control unit 110) controls the driving of the motor 40 by itself without superimposing the disturbance signal ω N can be superimposed, and the disturbance signal ω N By superimposing the above, the motor control IC 10 (motor control unit 110) continues to control the drive of the motor 40, while the frequency characteristic derivation unit 32 derives the frequency characteristic.

[0054] This is particularly useful in applications where stopping the motor drive for measuring the frequency characteristics is not permitted (for example, an application where the motor 40 is used to constantly operate a fan in a base station). For example, since deterioration of the motor 40 is considered to be accompanied by a change in the frequency characteristics, if an administrator as a user periodically checks the frequency characteristics, the degree of deterioration of the motor 40 can be estimated, and the motor 40 can be replaced as necessary. Note that a hypothetical configuration is also considered in which the operation mode is selectively set to the normal mode or the measurement mode when the motor control device is started, and the frequency characteristics can be measured only in the measurement mode, but this hypothetical configuration is not suitable for the above-mentioned application. In the configuration according to this embodiment, it is sufficient to connect the external debug device (20, 30) to the motor control IC 10 at a desired timing during the operation of the motor control IC 10 and the motor 40, and execute the frequency characteristics measurement process.

[0055] Furthermore, since the external debug device (20, 30) has an inherent debug function, it can monitor other signals (hereinafter referred to as monitored signals) in the motor control IC 10 at any desired timing. N The disturbance signal ω may be any timing during a specific period in which the frequency characteristic is derived through superposition of the disturbance signal ω. N During the period when the superposition of is performed (i.e., the non-zero disturbance signal ω N is the speed command ω * The period in which the signal is superimposed on the motor control IC 10 belongs to the specific period. The monitored signal may be any signal that is recognized and handled within the motor control IC 10. However, the monitored signal may be a signal that is referenced by the frequency characteristic derivation unit 32 to derive the frequency characteristic (i.e., the above-mentioned first calculation value (ω * -ω) and the second calculated value (ω * -ω+ω N) is different from the signal indicating the motor current i or the rotor position θ. For example, the monitored signal may be a signal indicating the motor current i or a signal indicating the rotor position θ. Alternatively, the monitored signal may be a temperature signal indicating the temperature at a specific measurement target position in the motor drive system. The measurement target position may be the temperature within the motor control IC 10 or may be a temperature outside the motor control IC 10 (for example, the temperature at a specific position in the motor 40).

[0056] Disturbance signal ω N By making it possible to monitor any other signal while the frequency characteristic is being derived through the superposition of, detailed evaluation of the control loop is possible or necessary debugging work is facilitated. In a method other than this embodiment, it is considered that a separate tool is required to refer to the other signal.

[0057] 7, a transfer function estimating unit 34 and a gain adjusting unit 35 may be further provided in the host PC 30. The functions of the transfer function estimating unit 34 and the gain adjusting unit 35 are realized by executing debug software 31 (see FIG. 1) in the host PC 30. The operation or non-operation of the transfer function estimating unit 34 may be arbitrarily set by the user. The same applies to the gain adjusting unit 35.

[0058] The transfer function estimation unit 34 estimates a transfer function of a control loop in the motor control unit 110 based on the frequency characteristic derived by the frequency characteristic derivation unit 32. In the configuration of FIG. 5, the estimated transfer function is * is an input of the speed control loop and the rotation speed ω is output, and is a mathematical expression of the frequency characteristic derived by the frequency characteristic derivation unit 32. The transfer function estimation unit 34 can display the estimated transfer function on the display unit 33.

[0059] It is possible to apply some analytical model based on a mathematical formula to the motor 40, and to estimate the transfer function based on the analytical model. For example, if the motor 40 deteriorates, the frequency characteristics will change, and the transfer function will also change accordingly. By referring to the estimated transfer function, the user can consider replacing the motor 40 due to deterioration, or consider adjusting the control parameters of the motor 40.

[0060] The gain adjustment unit 35 adjusts (i.e. increases or decreases) the gain G_ω of the control loop (here, the speed control loop) based on the estimated transfer function. At this time, the gain adjustment unit 35 determines a recommended gain based on the estimated transfer function in accordance with a predetermined adjustment rule aimed at realizing stable control of the motor 40, and sets the recommended gain to the adjusted gain G_ω. This promotes stable control of the motor 40.

[0061] A method for adjusting the gain of any control loop is known, and the gain adjustment unit 35 may adjust the gain G_ω using any known gain adjustment method (for example, the gain adjustment method described in JP 2016-92935 A). For example, the current command i * When speed control section 115 is configured so that the following can be obtained, gain G_ω can be increased or decreased by increasing or decreasing the adjustment coefficient in speed control section 115 .

[0062] The process of changing the gain G_ω from gain G_ω1 to gain G_ω2 by the gain adjustment unit 35 can be performed as follows. That is, the gain adjustment unit 35 transmits a gain adjustment request signal including information about the gain G_ω2 to the debugger 20, and the debugger 20 transmits the information about the gain G_ω2 to the motor control IC 10 in response to receiving the gain adjustment request signal. The information about the gain G_ω2 is transmitted to the motor control unit 110 via the debug control unit 14, whereby the gain G_ω is changed from gain G_ω1 to gain G_ω2.

[0063] For convenience, the frequency characteristic derived in the frequency characteristic measurement process before the adjustment of the gain G_ω is referred to as the first frequency characteristic, and the Bode diagram based on the first frequency characteristic is referred to as the first Bode diagram. After the adjustment of the gain G_ω (in other words, after the gain G_ω is changed), the external debug device (20, 30) executes the frequency characteristic measurement process again. For convenience, the frequency characteristic derived in the frequency characteristic measurement process again is referred to as the second frequency characteristic, and the Bode diagram based on the second frequency characteristic is referred to as the second Bode diagram. After the second Bode diagram is obtained through the adjustment of the gain G_ω, the gain adjustment unit 35 may replace the Bode diagram displayed on the display unit 33 from the first Bode diagram to the second Bode diagram, or may display the first and second Bode diagrams in parallel on the display unit 33. This allows the user to visually confirm the effect of the adjustment of the gain G_ω.

[0064] <<Second embodiment>> The second embodiment of the present disclosure will be described. The second embodiment and the third embodiment described later are based on the first embodiment, and for matters not specifically mentioned in the second and third embodiments, the description of the first embodiment also applies to the second and third embodiments unless there is a contradiction. When interpreting the description of the second embodiment, the description of the second embodiment may take precedence for matters that contradict between the first and second embodiments (the same applies to the third embodiment described later). As long as there is no contradiction, any two or more of the first to third embodiments may be combined.

[0065] In the motor drive system according to the present disclosure, the control loop for which frequency characteristics are to be measured is not limited to the speed control loop. As an example, FIG. 8 shows a configuration in which a current control loop is set as the frequency characteristic measurement target. FIG. 8 is a functional block diagram of a motor drive system according to a second embodiment. The configuration and operation of the motor control unit 110 provided in the motor control IC 10 and the configurations and operations of the driver 50 and motor 40 are the same as those shown in the first embodiment. However, in the configuration of FIG. 8, the speed command ω * Instead, the current command i * For disturbance signal i NThe frequency characteristic of the current control loop is measured by superimposing the current on the frequency characteristic of the current control loop. In the following, a description of common points between the first and second embodiments will be omitted, and only differences between them will be described.

[0066] As described above, the subtractor 116 subtracts the signal of the motor current i detected by the current detection unit 114 and the current command i supplied from the speed control unit 115. * When calculating the current error Δi, the debugger 20 outputs a disturbance signal i N may be input to the subtractor 116 (i.e., the current command i * Disturbance signal i N The required current error Δi is “Δi = i * -i+i N In FIG. 8, the disturbance signal i N is input to the subtractor 116. The disturbance signal i N In the situation where "i N =0”, so “Δi=i * -i".

[0067] Two feedback loops are formed in the motor control unit 110. Of the two feedback loops, one is a speed control loop as a main loop, and the other is a current control loop as a minor loop. The current control loop is a current command i * The current control loop is a control loop (feedback control system) having a current command i as an input and a motor current i as an output, and is formed by including components denoted by reference numerals 114, 116, 117, and 50. * The current control is realized to make the motor current i match or approach the disturbance signal i. N is input to the subtractor 116, the disturbance signal i N is the current command i * Since the current control loop is superimposed on the current command (i * +i N ) as input and the motor current i as output, and the superimposed current command (i * +iN ) and performs current control to make the motor current i match or approach it.

[0068] The frequency characteristic measurement process according to the configuration will be described with reference to Fig. 8. When a user inputs a predetermined frequency characteristic measurement instruction operation to the host PC 30, a request signal 71a is sent from the host PC 30 (for example, from the frequency characteristic derivation unit 32) to the debugger 20. When the debugger 20 receives the request signal 71a, the disturbance signal superimposition unit 22 superimposes the disturbance signal i N Generate the disturbance signal i N is output to the motor control IC 10. The disturbance signal i N is introduced into the control loop of the motor control unit 110 through the debug control unit 14 (see FIG. 3), and specifically becomes an input signal to the adder 116.

[0069] Disturbance signal i N is a noise that includes signal components of each frequency in a predetermined measurement band. N By sweeping the frequency of i, noise containing signal components of each frequency within the measurement band is generated. N is generated as a digital disturbance signal with the dimension of a current. N The type of noise as the disturbance signal i is arbitrary. N The noise as the disturbance signal i may be, for example, white noise or colored noise (pink noise, gray noise, etc.). N The characteristics of the disturbance signal i (such as the measurement band and signal amplitude) are specified. N is generated.

[0070] As described above, the subtractor 116 calculates “Δi=i * -i+i N In practice, for example, the first calculation value (i * After calculating the second calculation value (i * -i+i NIn the frequency characteristic measurement process, the debug control unit 14 (see FIG. 3) calculates a first calculation value (i * -i) and the second calculation value (i * -i+i N ) is read from the subtractor 116, and the first calculation value (i * -i) and the second calculation value (i * -i+i N ) to the debugger 20. In practice, for example, the first and second operation values ​​are stored in a specific storage area in the memory 12 (which may be a register of the CPU 11), and the debug control unit 14 acquires the first and second operation values ​​by reading the stored data in the specific storage area.

[0071] The result signal 72a is transferred from the debugger 20 to the host PC 30, and the frequency characteristic derivation unit 32 derives the frequency characteristic of the control loop of the motor control unit 110 based on the result signal 72a. The frequency characteristic derived here is the frequency characteristic of the current control loop for the motor 40 (hereinafter, simply referred to as the frequency characteristic in this embodiment).

[0072] In the host PC 30, a frequency characteristic derivation unit 32 creates a Bode diagram as a diagram showing the derived frequency characteristic, and displays the created Bode diagram on a display unit 33. The Bode diagram is composed of a gain diagram showing the frequency dependency of the gain of the control loop, and a phase diagram showing the frequency dependency of the phase of the control loop. The control loop of interest in this embodiment is a current control loop that performs current control. For convenience, the gain and phase in the current control loop are referred to as G_i and P_i, respectively. The gain G_i and phase P_i are expressed as a function of the current command i. * It represents the gain and phase of the transfer function with the motor current i as the output and the input of the current command i. * represents the ratio of the amplitude of the motor current i to the amplitude of the current command i, and the phase P_i * The current command i based on the signal * represents the phase difference between the signal of motor current i and the signal of motor current i.

[0073] In the second embodiment, similarly to the first embodiment, the external debugging device (20, 30) can be connected to the motor control IC 10 at any timing during the drive control of the motor 40 to perform the frequency characteristic measurement process. N Starting from a state where the motor control IC 10 (motor control unit 110) controls the driving of the motor 40 by itself without superimposing the disturbance signal i N can be superimposed, and the disturbance signal i N By superimposing the above, the motor control IC 10 (motor control unit 110) continues to control the drive of the motor 40, while the frequency characteristic derivation unit 32 derives the frequency characteristic (the frequency characteristic of the current control loop).

[0074] In addition, the techniques described in the first embodiment are applied to the second embodiment unless there is a contradiction. However, when applying the techniques, the disturbance signal ω N In the second embodiment, the disturbance signal i N That is, for example, in the configuration of Fig. 8, a transfer function estimating unit 34 and a gain adjusting unit 35 (see Fig. 7) may be provided in the host PC 30, and the transfer function estimating unit 34 estimates a transfer function of a control loop in the motor control unit 110 based on the frequency characteristic derived by the frequency characteristic deriving unit 32. In the configuration of Fig. 8, the estimated transfer function is * is a transfer function of a current control loop having an input of and an output of the motor current i, and is a mathematical expression of the frequency characteristic derived by the frequency characteristic derivation unit 32. The transfer function estimation unit 34 can display the estimated transfer function on the display unit 33. Furthermore, the gain adjustment unit 35 can adjust (i.e., increase or decrease) the gain of the control loop (here, the current control loop) based on the estimated transfer function.

[0075] The configuration capable of measuring the frequency characteristic of the current control loop has been described with reference to FIG. 8. In addition, for example, the rotor position θ can be calculated based on the position command θ * In this case, it is possible to form a position control loop in the motor control unit 110 in accordance with the position command θ *By superimposing a disturbance signal on the position control loop, the frequency characteristics of the position control loop can be derived.

[0076] <<Third embodiment>> A third embodiment of the present disclosure will be described.

[0077] The motor control system according to the present disclosure, specific examples of which are shown in the first and second embodiments, is a motor control system including: a motor control device that is configured with a semiconductor integrated circuit having a memory (12) and forms a control loop (e.g., a speed control loop) for a motor (40) to control driving of the motor; and an external debug device (20, 30) that is externally connected to the motor control device and has access to the memory, and N The external debug device is provided with a disturbance signal superposition unit (22) that generates a disturbance signal (a disturbance signal) and superposes the disturbance signal on the signal in the control loop, and a frequency characteristic derivation unit (32) that derives the frequency characteristic of the control loop based on the signal generated in the control loop by the superposition. Here, the motor control device can be considered to correspond to the motor control IC 10 or to correspond to the motor control unit 110.

[0078] In the first embodiment (see FIG. 5), the disturbance signal ω N In practice, the introduction (injection) of is realized by an operation on the memory 12 in which the input / output data of the subtractor 113 is stored. Similarly, in the second embodiment (see FIG. 8), the disturbance signal i N The introduction (injection) of the disturbance signal is actually realized by operating the memory 12 in which the input / output data of the subtractor 116 is stored. According to the method of introducing the disturbance signal by operating the memory, the disturbance signal can be freely introduced (injected) at any point in the control loop. This is a significant advantage over the method of pulling out a signal line of the hardware and directly injecting the disturbance signal into the target part via the signal line.

[0079] The method of deriving the frequency characteristic of the control loop, the specific example of which is shown in the first and second embodiments, can be applied to any device or system having a control loop (feedback control system). For example, when the DC input voltage V IN to other DC output voltage V OUT The above derivation method can be applied to a power supply device (DC / DC converter) that generates an output voltage V OUT Feedback voltage V proportional to FB and a given reference voltage V REF The amplified signal of the difference between ERR and the error voltage V ERR Feedback control to match or approach zero (hence feedback voltage V FB is the reference voltage V REF This results in a feedback control that makes the output voltage V OUT is the reference voltage V REF The voltage is stabilized at a target voltage according to the

[0080] When measuring the frequency characteristics of the control loop in this power supply, the reference voltage V REF The disturbance signal V N The disturbance signal V N During the period when the superposition of the feedback voltage V FB and voltage (V REF +V N ) is adjusted to zero or close to zero. REF -V FB ) and (V REF -V FB +V N ) based on the feedback voltage V FB is the reference voltage V REF It is possible to derive the frequency characteristic of a control loop (feedback control system) that matches or approaches the above.

[0081] The embodiments of the present disclosure can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims. The above embodiments are merely examples of the embodiments of the present disclosure, and the meanings of the terms of the present disclosure or each component are not limited to those described in the above embodiments. The specific numerical values ​​shown in the above description are merely examples, and can be changed to various numerical values ​​as a matter of course. [Explanation of symbols]

[0082] 10 Motor Control IC 20 Debugger 22 Disturbance signal superimposition section 30 Host Computer 31 Debugging Software 32 Frequency characteristic derivation section 33 Display section 34 Transfer function estimation section 35 Gain adjustment section 40 Motor 50 Drivers 110 Motor control unit

Claims

1. a motor control device that is configured with a semiconductor integrated circuit having a memory and that forms a control loop for a motor to control driving of the motor; an external debug device externally connected to the motor control device and capable of accessing the memory, the external debugging device is provided with a disturbance signal superposition unit that generates a disturbance signal for the control loop and superposes the disturbance signal on a signal in the control loop, and a frequency characteristic derivation unit that derives a frequency characteristic of the control loop based on the signal generated in the control loop by the superposition; the motor control device is configured to be operable independently of the external debug device, and generates a speed command representing a target value of a rotation speed of the motor, and the disturbance signal superimposing unit superimposes the disturbance signal on the speed command generated by the motor control device or on a signal based on the speed command; the external debug device is configured to be able to monitor a signal indicating a temperature at a predetermined measurement target position in the motor control system during a period in which the disturbance signal is superimposed; the external debugging device includes a debugger including the disturbance signal superimposing unit and a calculation unit including the frequency characteristic derivation unit, the debugger being externally connected to the motor control device; the debugger is disposed between the arithmetic unit and the motor control unit, and performs superimposition of the disturbance signal under the instruction of the arithmetic unit; A signal generated in the control loop by the superposition is transmitted from the motor control device to the arithmetic unit via the debugger. Motor control system.

2. The disturbance signal superimposing unit introduces the disturbance signal into the control loop through the memory. The motor control system of claim 1 .

3. The external debugging device further includes a display unit that displays a Bode diagram as a diagram representing the frequency characteristic.

3. A motor control system according to claim 1 or 2.

4. Starting from a state in which the motor control device controls the drive of the motor by itself without superimposing the disturbance signal, when the disturbance signal is superimposed, the frequency characteristic is derived by the frequency characteristic derivation unit while the motor control device continues to control the drive of the motor.

4. The motor control system according to claim 1.

5. the external debug device is capable of monitoring other signals in the motor control device while performing the process of deriving the frequency characteristic through the superposition of the disturbance signal; The other signal is a signal different from the signal referred to by the frequency characteristic derivation unit for deriving the frequency characteristic.

5. A motor control system according to claim 1.

6. The external debugging device further includes a transfer function estimating unit that estimates a transfer function of the control loop based on the derived frequency characteristic.

6. A motor control system according to claim 1.

7. The external debugging device further includes a gain adjustment unit that adjusts a gain of the control loop based on the estimated transfer function.

7. The motor control system of claim 6.

8. the motor control device performs speed control in the control loop to make the rotational speed of the motor coincide with or approach the speed command; The disturbance signal superimposing unit superimposes the disturbance signal on the speed command. A motor control system according to any one of claims 1 to 7.

9. The disturbance signal superimposing unit generates digital noise including signal components of each frequency within a predetermined band as the disturbance signal. A motor control system according to any one of claims 1 to 8.

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