Gain adjustment device for resolver, motor control device, and motor device

Abstract

To automatically adjust the gain of a circuit that adjusts the phase and amplitude of a signal related to a resolver to the gain that has the phase and amplitude conforming to the specifications of an RDC.SOLUTION: A gain adjustment device 47 for a resolver comprises: a microcomputer 43; an A / D converter 47a; a phase adjustment circuit 47b including an operational amplifier OP1 for phase adjustment of a first excitation signal and a first DP 471 for adjusting the gain of the operational amplifier OP1; and an amplitude adjustment circuit 47c including an operational amplifier OP2 for amplitude adjustment of the first excitation signal, and a second DP 472 and a third DP 473 for adjusting the gain of the operational amplifier OP2. The microcomputer 43 adjusts values of ladder resistors Rd1 to Rd3 of the first to third DPs 471 to 473 such that a phase difference between the first excitation signal and a first sine wave signal and a first cosine wave signal, and peak-to-peak values of the first sine wave signal and the first cosine wave signal fall within specification ranges of an RDC 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resolver gain adjustment device, a motor control device, and a motor device that adjusts the gain of a circuit for adjusting the phase and amplitude of a signal related to a resolver so that the phase and amplitude fall within the specification range of a resolver-to-digital converter (hereinafter abbreviated as "RDC"). [Background technology]

[0002] Conventionally, there is a technique for adjusting the gain of a combiner that combines two-phase signals output from a resolver to modulate the phase (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-101384 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, the gain of a combiner that combines two-phase signals output from a resolver is changed in accordance with changes in the rotor rotation speed of the resolver for the purpose of noise removal. Therefore, for example, when the resolver connected to the RDC is replaced with a different type of resolver or when a new resolver is connected, it is not possible to automatically adjust the gain of the combiner to a gain that complies with the RDC specifications. Therefore, an object of the present invention is to provide a resolver gain adjustment device, a motor control device, and a motor device that can automatically adjust the gain of a circuit that adjusts the phase and amplitude of a signal related to a resolver to a gain that results in a phase and amplitude that comply with the RDC standard. [Means for solving the problem]

[0005] In order to solve the above problem, one embodiment of the resolver gain adjustment device of the present invention includes a phase adjustment circuit having a first amplifier for adjusting the phase of an excitation signal output from an RDC or an electrical signal output from a resolver attached to a rotating shaft of a motor and excited by the excitation signal, and a first digital potentiometer for adjusting the gain of the first amplifier; an amplitude adjustment circuit having a second amplifier for adjusting the amplitude of the excitation signal or the electrical signal, and a second digital potentiometer for adjusting the gain of the second amplifier; and a signal adjusting circuit for acquiring the excitation signal and the electrical signal corresponding to a rotation of 360° or more of the motor. a signal acquisition unit, a phase difference calculation unit that calculates a phase difference between the excitation signal and the electrical signal based on the excitation signal and the electrical signal acquired by the signal acquisition unit, a peak-to-peak value calculation unit that calculates a peak-to-peak value of the electrical signal based on the electrical signal acquired by the signal acquisition unit, a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the RDC, and an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit falls within a specification range of the peak-to-peak value of the RDC.

[0006] As a result, by adjusting the value of the first digital potentiometer, the phase difference between the excitation signal and the electrical signal can be adjusted so that it falls within the RDC's specification range. In addition, by adjusting the value of the second digital potentiometer, the amplitude can be adjusted so that the peak-to-peak value of the electrical signal falls within the RDC's specification range. As a result, a control unit having a processor such as a microcomputer can automatically adjust the values of the first digital potentiometer and the second digital potentiometer. This eliminates the need for manual adjustment each time the resolver connected to the RDC is replaced with a different type of resolver or a new resolver is connected.

[0007] In addition, in order to solve the above problem, a resolver gain adjustment device according to one embodiment of the present invention includes a first A / D converter that converts an analog first excitation signal output from an RDC into a digital second excitation signal and outputs the digital second electrical signal; a second A / D converter that converts an analog first electrical signal output from a resolver that is attached to a rotating shaft of a motor and is excited by the first excitation signal into a digital second electrical signal and outputs the digital second electrical signal; a phase adjustment circuit that has a first amplifier for adjusting the phase of the first excitation signal or the first electrical signal and a first digital potentiometer for adjusting the gain of the first amplifier; an amplitude adjustment circuit that has a second amplifier for adjusting the amplitude of the first excitation signal or the first electrical signal and a second digital potentiometer for adjusting the gain of the second amplifier; and a control unit. In addition, the control unit includes a signal value acquisition unit that acquires signal values of the second excitation signal and the second electric signal output from the first A / D converter and the second A / D converter in response to a rotation of 360° or more of the motor; a phase difference calculation unit that calculates a phase difference between the second excitation signal and the second electric signal based on the signal value of the second excitation signal and the signal value of the second electric signal acquired by the signal value acquisition unit; a peak-to-peak value calculation unit that calculates a peak-to-peak value of the second electric signal based on the signal value of the second electric signal acquired by the signal value acquisition unit; a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the RDC; and an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit falls within a specification range of the peak-to-peak value of the RDC.

[0008] This allows the control unit to automatically adjust the value of the first digital potentiometer so that the phase difference falls within the specification range of the phase difference of the RDC. In addition, the control unit can automatically adjust the value of the second digital potentiometer so that the peak-to-peak value falls within the specification range of the peak-to-peak value of the RDC. As a result, it is possible to save the trouble of manually adjusting the value each time, for example, when the resolver connected to the RDC is replaced with a resolver of a different type or when a new resolver is connected.

[0009] In addition, in the above-described resolver gain adjustment device, the first excitation signal may be a one-phase or two-phase excitation signal, the resolver may be a one-phase or two-phase excitation and two-phase output type resolver, and the first electrical signal output from the resolver may be a two-phase electrical signal. In this case, the phase difference between the one-phase or two-phase excitation signal and the two-phase electrical signal, and the peak-to-peak value of the two-phase electrical signal can be automatically adjusted to fall within the RDC standard range. Furthermore, in the resolver gain adjustment device, the phase difference calculation means may calculate the phase difference based on time information of zero cross points of the second excitation signal and the second electrical signal. In this case, the phase difference can be easily calculated from the signal value at the zero cross point. The resolver gain adjustment device may further include a motor rotation control section that rotates the motor by 360° or more by energization control using a back electromotive force. In this case, the motor can be rotated automatically, eliminating the need to rotate the motor manually or by an external device, thereby reducing the manual labor and the costs and size of the external device.

[0010] In the resolver gain adjustment device described above, the control unit may include a recording unit that records, on a recording medium, the value of the first digital potentiometer after the phase difference has been adjusted to fall within the specified range and the value of the second digital potentiometer after the peak-to-peak value has been adjusted to fall within the specified range. In this case, the adjusted values can be recorded, so that when a resolver of the same model number is connected, the recorded values can be reused. As a result, it is possible to use the values as the initial values for automatic adjustment or to omit part of the automatic adjustment.

[0011] Furthermore, a motor control device according to one embodiment of the present invention includes an RDC that outputs an analog first excitation signal that excites a resolver attached to a rotating shaft of a motor, and outputs a digital angle signal corresponding to the rotational position of the motor based on the analog first electrical signal output from the resolver; a first A / D converter that converts the first excitation signal output from the RDC into a digital second excitation signal and outputs it; a second A / D converter that converts the first electrical signal output from the resolver into a digital second electrical signal and outputs it; a phase adjustment circuit having a first amplifier for adjusting the phase of the first excitation signal or the first electrical signal and a first digital potentiometer for adjusting a first gain of the first amplifier; an amplitude adjustment circuit having a second amplifier for adjusting the amplitude of the first excitation signal or the first electrical signal and a second digital potentiometer for adjusting the second gain of the second amplifier; and a control unit. Additionally, the control unit includes a mode setting unit that sets an automatic adjustment mode in response to an input of a setting instruction signal for an automatic adjustment mode that automatically adjusts the first gain and the second gain, and sets the motor operation mode in response to an input of a setting instruction signal for a motor operation mode that controls operation of the motor; a signal value acquisition unit that acquires values of the second excitation signal and the second electric signal output from the first A / D converter and the second A / D converter in response to a rotation of 360° or more of the motor in response to the setting of the automatic adjustment mode; and a phase difference calculation unit that calculates a phase difference between the value of the second excitation signal and the value of the second electric signal based on the value of the second excitation signal and the value of the second electric signal acquired by the signal value acquisition unit. The apparatus includes a peak-to-peak value calculation unit that calculates a peak-to-peak value of the second electrical signal based on the value of the second electrical signal acquired by the signal value acquisition unit; a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the RDC; an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit falls within a specification range of the peak-to-peak value of the RDC; and a motor operation control unit that controls operation of the motor based on the angle signal output from the RDC in accordance with the setting of the motor operation mode. This provides the same functions and effects as the resolver gain adjustment device described above. In addition, the mode can be easily switched between the automatic adjustment mode and the motor operation mode. Furthermore, a motor device according to one aspect of the present invention includes a motor, a resolver attached to a rotary shaft of the motor, and the motor control device according to claim 7 . This provides the same functions and effects as the resolver gain adjustment device and motor control device described above. [Effects of the Invention]

[0012] According to one aspect of the present invention, the gain of a circuit that adjusts the phase and amplitude of a signal related to a resolver can be automatically adjusted to a gain that results in a phase and amplitude that comply with the RDC standard. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram showing the configuration of a motor device 1 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a phase adjustment circuit unit of a phase adjustment circuit. [Figure 3] 2 is a diagram illustrating a configuration of an amplitude adjustment circuit section of an amplitude adjustment circuit. FIG. [Figure 4] FIG. 2 is a block diagram showing the functional configuration of a microcomputer. [Figure 5] 10 is a flowchart illustrating an automatic adjustment process. [Figure 6] FIG. 10 is a diagram showing a signal flow when an automatic adjustment mode is set. [Figure 7] FIG. 10 is a waveform diagram for explaining a method of calculating a phase difference using a zero crossing point. [Figure 8] FIG. 10 is a waveform diagram showing an example of an adjustment range of a phase difference. [Figure 9] FIG. 10 is a diagram showing the flow of a command signal when adjusting a phase gain and an amplitude gain. [Figure 10] 10 is a flowchart showing a motor operation process. [Figure 11]FIG. 10 is a diagram showing a signal flow when a motor operation mode is set. [Figure 12] FIG. 10 is a block diagram showing the configuration of a motor device 1A according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiment described below is an example of a means for realizing the present invention, and should be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the embodiment described below.

[0015] In addition, in the following description of the drawings, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the vertical and horizontal dimensions and scales of the components or parts may differ from those of the actual parts. Therefore, the specific dimensions and scales should be determined by taking into consideration the following explanation. Furthermore, it goes without saying that the dimensional relationships and ratios may differ between the drawings.

[0016] (composition) First, an embodiment of the present invention will be described, with reference to Figures 1 to 10 showing the embodiment. FIG. 1 is a block diagram showing a schematic configuration of a motor device 1 according to an embodiment. [Hardware configuration] The motor device 1 includes an electric motor 2, a resolver 3, and a motor control device 4. The electric motor 2 may be, for example, a three-phase brushless motor.

[0017] The three-phase brushless motor includes an annular motor rotor and an annular motor stator (not shown). The motor stator has multiple pole teeth that protrude radially outward and are spaced equally apart in the circumferential direction, with an excitation coil wound around each pole tooth. The motor rotor is coaxially disposed outside the motor stator. The motor rotor faces the pole teeth of the motor stator across a small air gap and includes multiple magnets that are spaced equally apart in the circumferential direction on its inner surface. The motor rotor is fixed to the motor shaft, and by passing a three-phase AC current through the coils of the motor stator via the motor drive circuit 49, the teeth of the motor stator are excited in a predetermined sequence, causing the motor rotor to rotate, and this rotation in turn causes the motor shaft to rotate. The resolver 3 is attached to the motor rotating shaft and may be, for example, a one-phase excitation / two-phase output type unipolar VR (variable reluctance) resolver.

[0018] The resolver 3 includes an annular resolver rotor and an annular resolver stator (not shown). The resolver stator has one primary winding and two secondary windings. The resolver 3 operates as a variable coupling transformer in which the amount of magnetic coupling between the one primary winding and the two secondary windings changes depending on the position of the resolver rotor. With this configuration, the resolver 3 outputs a two-phase electric signal according to the rotational angle position of the resolver rotor (that is, the rotational angle position of the electric motor 2). The motor control device 4 includes an RDC 41 , a microcomputer 43 , a switch 45 , a resolver gain adjuster 47 , and a motor drive circuit 49 . Although not shown, the RDC 41 includes an excitation circuit that has an oscillator and supplies an analog differential excitation signal to the resolver 3, and an A / D converter. The analog differential excitation signal is shown in Figure 1 etc. as exc and exc with a bar above it to indicate that it is its inverted signal. Hereinafter, the analog differential excitation signal will be referred to as the "first excitation signal."

[0019] Here, a first excitation signal from the RDC 41 is supplied to the primary winding of the resolver 3. As a result, the resolver 3 outputs an analog differential sine wave signal corresponding to the position of the resolver rotor from one of the two secondary windings, and outputs an analog differential cosine wave signal corresponding to the position of the resolver rotor from the other secondary winding. Analog differential sine signals are shown in Figure 1 as sin with a bar over it to indicate that it is sin and its inverse, and analog differential cosine signals are shown in Figure 1 as cos and cos with a bar over it to indicate that it is cos and its inverse. Hereinafter, the analog differential sine wave signal will be referred to as a "first sine wave signal," and the analog differential cosine wave signal will be referred to as a "first cosine wave signal." The RDC 41 converts the first sine wave signal and the first cosine wave signal from the resolver 3 into a digital angle signal φ. Then, the RDC 41 outputs the digital angle signal φ to the microcomputer 43.

[0020] Although not shown, the microcomputer 43 is composed of a CPU (Central Processing Unit) that controls calculations and the entire device based on a control program, a ROM (Read Only Memory) that stores the CPU's control program and the like in advance in a specified area, a RAM (Random Access Memory) for storing data read from the ROM and the calculation results required in the CPU's calculation process, and an I / F (Interface) that mediates the input and output of data to and from external devices, and these are connected to each other and capable of sending and receiving data by a bus, which is a signal line for transferring data.

[0021] The switch 45 has a switching unit (such as a button or a lever) for switching between an automatic adjustment mode that automatically adjusts the phase and amplitude of the first excitation signal and a motor operation mode that controls the operation of the electric motor 2. The switch 45 outputs a mode setting signal MS to the microcomputer 43, which indicates a setting instruction according to the switching position of the switching unit.

[0022] The resolver gain adjustment device 47 includes a microcomputer 43, an A / D converter 47a, a phase adjustment circuit 47b, and an amplitude adjustment circuit 47c. That is, in this embodiment, the microcomputer 43 is shared by the motor control device 4 and the resolver gain adjustment device 47. The A / D converter 47a is a known A / D converter that converts an input analog signal into an N-bit (N is a natural number equal to or greater than 2) digital signal. In this embodiment, it is configured as, for example, a 12-bit A / D converter. The first excitation signal, the first sine wave signal, and the first cosine wave signal are input to the A / D converter 47a, and are converted into digital signals. The digital first excitation signal is shown in FIG. 1 as dexc with a bar over it to indicate that it is dexc and its inverse.

[0023] Also, the digital first sine signal is shown in FIG. 1 as dsin with a bar over it to indicate that it is dsin and its inverse, and the digital first cosine signal is shown in FIG. 1 as dcos and its inverse with a bar over it to indicate that it is dcos. Hereinafter, the converted digital first excitation signal will be referred to as the "second excitation signal," the digital first sine wave signal will be referred to as the "second sine wave signal," and the digital first cosine wave signal will be referred to as the "second cosine wave signal." The second excitation signal, the second sine wave signal, and the second cosine wave signal are each input to the microcomputer 43.

[0024] Fig. 2 is a diagram showing the configuration of a phase adjustment circuit section 470b of the phase adjustment circuit 47b, and Fig. 3 is a diagram showing the configuration of an amplitude adjustment circuit section 470c of the amplitude adjustment circuit 47c. Fig. 6 is a diagram showing the flow of signals when the automatic adjustment mode is set. As shown in FIG. 6, the phase adjustment circuit 47b includes two phase adjustment circuit sections 470b for adjusting the phases of one signal of the first cosine wave signal, which is a differential signal, and its inverted signal, respectively.

[0025] As shown in FIG. 2, each phase adjustment circuit section 470b includes a resistor R1, a resistor R2, a capacitor C1, an operational amplifier OP1, and a first digital potentiometer 471 (hereinafter referred to as "first DP 471"). The operational amplifier OP1 is a known operational amplifier. One end of the resistor R1 is connected to the negative terminal of the operational amplifier OP1 and one end of the resistor R2, and the other end is connected to the signal line of the first excitation signal and one end of the capacitor C1. The other end of the capacitor C1 is connected to the positive terminal of the operational amplifier OP1 and one end of the ladder resistor Rd1 of the first DP471. The other end of the resistor R2 is connected to the output terminal of the operational amplifier OP1, and the other end of the ladder resistor Rd1 is connected to a reference voltage REFOUT (for example, 0 V). The output terminal of the operational amplifier OP1 is connected to the amplitude adjustment circuit 47c. Although not shown, the first DP 471 includes an interface circuit with the microcomputer 43, a register, a ladder resistor Rd1 composed of multiple resistive elements, and an electronic switch that switches the connections of the multiple resistive elements that make up the ladder resistor Rd1. The register switches the electronic switch in response to a command signal from the microcomputer 43 to change the resistance value of the ladder resistor Rd1 to a value specified by the command signal.

[0026] With this configuration, each phase adjustment circuit unit 470b can adjust the gain of the operational amplifier OP1 (hereinafter referred to as "phase gain") that contributes to the phase of the input first excitation signal by adjusting the resistance value of the ladder resistor Rd1 as shown in the following equation (1). In other words, it is possible to adjust the phase of the first excitation signal in units according to the resolution of the first DP 471.

[0027]

number

[0028] Furthermore, each phase adjustment circuit unit 470b can automatically change the value of the ladder resistor Rd1 in response to a command signal from the microcomputer 43, and can automatically adjust the phase gain. As shown in FIG. 6, the amplitude adjustment circuit 47c includes two amplitude adjustment circuit sections 470c for adjusting the amplitude of one signal of the first excitation signal, which is a differential signal, and its inverted signal, respectively. As shown in FIG. 3, each amplitude adjustment circuit section 470c includes an operational amplifier OP2, a second digital potentiometer 472 (hereinafter referred to as "second DP 472"), and a third digital potentiometer 473 (hereinafter referred to as "third DP 473"). The operational amplifier OP2 is a known operational amplifier. One end of the ladder resistor Rd2 is connected to the output terminal of the operational amplifier OP1 of the phase adjustment circuit section 470b, and the other end is connected to the negative terminal of the operational amplifier OP2 and one end of the ladder resistor Rd3. The other end of the ladder resistor Rd3 is connected to the output terminal of the operational amplifier OP2, and the positive terminal of the operational amplifier OP2 is connected to a reference potential REFOUT (for example, 0 V). The second DP 472 and the third DP 473 have the same configuration as the first DP 471, and change the resistance values of the ladder resistors Rd2 and Rd3 to the values specified by the command signal by switching the electronic switches in response to a command signal from the microcomputer 43.

[0029] Each amplitude adjustment circuit unit 470c forms a negative feedback circuit and amplifies the amplitude of the phase-adjusted first excitation signal input to the minus terminal by a gain (hereinafter referred to as "amplitude gain") according to the values of the ladder resistors Rd2 and Rd3 shown in the following equation (2). That is, the amplitude of the first excitation signal can be adjusted in units according to the resolution of the second DP 472 and the third DP 473. Amplitude gain = Vi × Rd3 / Rd2 (2) In the above equation (2), Vi is the voltage of the first excitation signal after phase adjustment. The motor drive circuit 49 includes a smoothing circuit, an inverter circuit, etc., and generates a drive signal (e.g., a PWM signal) to drive the electric motor 2 based on a control signal from the microcomputer 43, and supplies the generated drive signal to the electric motor 2.

[0030] In this embodiment, the first DP 471, the second DP 472, and the third DP 473 are each provided with a nonvolatile storage medium (for example, an EEPROM), and are configured to set the values of the ladder resistors Rd1, Rd2, and Rd3 to the values stored in the nonvolatile storage medium when the power is turned on. [Functional configuration] Next, the functional configuration of the microcomputer 43 will be described with reference to Fig. 4. Fig. 4 is a functional block diagram showing the functional configuration of the microcomputer 43.

[0031] 4, the microcomputer 43 includes, as functional blocks that function by executing a control program in the CPU, a mode setting unit 210, a motor rotation control unit 212, a signal value acquisition unit 214, and a phase difference calculation unit 216. In addition, the microcomputer 43 includes a peak-to-peak value calculation unit 218, a phase gain adjustment unit 220, an amplitude gain adjustment unit 222, a gain setting unit 224, and a motor operation control unit 226. The mode setting unit 210 sets the automatic adjustment mode or the motor operation mode in response to a mode setting signal MS from the switch 45 indicating a setting instruction corresponding to the switching position of the switching unit. In addition, each functional block surrounded by a dashed line in Figure 4 is a block that functions when the automatic adjustment mode is set, and each functional block surrounded by a dotted line is a block that functions when the motor operation mode is set.

[0032] The motor rotation control unit 212 generates three-phase command signals ucs, vcs, and wcs for rotating the electric motor 2 360° by energization control using back electromotive force, and outputs the generated command signals to the motor drive circuit 49. The signal value acquisition unit 214 samples the digital second excitation signal, second sine wave signal, and second cosine wave signal input to the microcomputer 43 at a predetermined sampling period when the electric motor 2 rotates 360° due to the power supply control by the motor rotation control unit 212. As a result, the time-series signal values of the second excitation signal, the second sine wave signal, and the second cosine wave signal are acquired. The acquired signal values are stored in a storage medium such as a RAM. The phase difference calculation unit 216 calculates the phase difference between the first excitation signal and the first sine wave signal or the first cosine wave signal based on each signal value of the second excitation signal acquired by the signal value acquisition unit 214 and each signal value of either the second sine wave signal or the second cosine wave signal.

[0033] Specifically, the phase difference is calculated based on, for example, time difference information of each signal value at the zero crossing point and the period of the first excitation signal. Since each signal value of the second excitation signal and the signal values of the second sine wave signal and the second cosine wave signal are signal values of differential signals, the phase differences α and α' between one of the differential signals and its inverted signal are calculated. The peak-to-peak value calculation unit 218 calculates the peak-to-peak value (hereinafter referred to as the "PP value") of the first sine wave signal or the first cosine wave signal based on the signal value of the second sine wave signal or the second cosine wave signal acquired by the signal value acquisition unit 214. Specifically, the PP value is calculated by adding the absolute values of the minimum and maximum values of the first sine wave signal or the first cosine wave signal. Since the signal values of the second sine wave signal and the second cosine wave signal are the signal values of the differential signal, the PP values pp and pp' of one of the differential signals and its inverted signal are calculated.

[0034] The phase gain adjustment unit 220 determines whether the phase differences α and α' calculated by the phase difference calculation unit 216 are within the specification range for the phase difference of the RDC 41. If it is determined that the phase differences α and α' are not within the specification range, it calculates the value of the ladder resistor Rd1 of the first DP 471 to bring the phase differences α and α' within the specification range. It then outputs command signals pgc and pgc' to the first DP 471 of one of the two phase adjustment circuit units 470b and the other of the two first DPs 471 to change the resistance value of the ladder resistor Rd1 to the calculated value. On the other hand, if it is determined that the phase differences are within the specification range, it ends the process without adjusting the ladder resistor Rd1.

[0035] Here, the value of the ladder resistor Rd1 of the first DP 471 for adjusting the phase gain can be calculated from the following equation (3). Also, the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 for adjusting the amplitude gain can be calculated from the following equations (4-1) and (4-2). Rd1 = current Rd1 value + (difference between standard phase and phase before adjustment) / Rd1 change per LSB (Least Significant Bit) (3) Rd2 = current Rd2 value + (difference between nominal voltage and unadjusted voltage) / Rd2 change per LSB (4-1) Rd3 = current Rd3 value + (difference between nominal voltage and unadjusted voltage) / Rd3 change per LSB (4-2)

[0036] The amplitude gain adjustment unit 222 determines whether the PP values pp and pp' calculated by the peak-to-peak value calculation unit 218 are within the specification range of the RDC 41. If it is determined that the PP values pp and pp' are not within the specification range, it calculates the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 so that the PP values pp and pp' are within the specification range. It then outputs command signals agc1 and agc2, and agc1' and agc2' to the second DP 472 and the third DP 473 of one and the other of the two amplitude adjustment circuits 470c, respectively, to change the resistance values of the ladder resistors Rd2 and Rd3 to the calculated values. On the other hand, if it is determined that the values are within the specification range, the processing ends without adjusting the ladder resistors Rd2 and Rd3. In addition, a nonvolatile storage medium such as a ROM of the microcomputer 43 stores in advance various pieces of specification information such as the specification range of the phase difference of the RDC 41 and the specification range of the PP value.

[0037] After adjusting the values of the ladder resistors Rd1, Rd2, and Rd3, the electric motor 2 is rotated 360° again, signal values are acquired, the phase difference and PP value are calculated, and the calculated values are compared with standard values. If the values are within the range of the standard values, the adjusted values of the ladder resistors Rd1, Rd2, and Rd3 are stored in a non-volatile storage medium. In this embodiment, the values are stored in the non-volatile storage media of the first DP 471, the second DP 472, and the third DP 473. On the other hand, if the second judgment still determines that the value is not within the standard range, a series of processes is repeated, from rotating the electric motor 2 360° until the value is within the standard range, to adjusting the values of the ladder resistors Rd1, Rd2, and Rd3 and judging the adjustment results.

[0038] [Automatic adjustment process] Next, the automatic adjustment process executed by the microcomputer 43 of the resolver gain adjuster 47 will be described with reference to FIGS. Fig. 5 is a flowchart showing the automatic adjustment process. Fig. 7 is a waveform diagram for explaining a method of calculating a phase difference using a zero crossing point. Fig. 8 is a waveform diagram showing an example of a phase difference adjustment range. Fig. 9 is a diagram showing the flow of a command signal when adjusting a phase gain and an amplitude gain. The CPU of the microcomputer 43 starts a control program stored in a predetermined area of the ROM, and executes the automatic adjustment process shown in the flowchart of FIG. 5 in accordance with the program. When the automatic adjustment process is executed by the CPU, as shown in FIG. 5, the process first proceeds to step S100.

[0039] In step S100, mode setting unit 210 determines whether or not it has received a mode setting signal MS indicating a setting instruction to switch to the automatic setting mode from switch 45, and if it determines that it has been received (Yes), it proceeds to step S102. On the other hand, if it determines that it has not been received (No), it repeats the determination process until it is received.

[0040] Here, the switching of the switching unit of switch 45 is performed manually by the user. Furthermore, switching to the automatic adjustment mode is usually performed when a new resolver different from the resolver previously connected is connected. For example, when evaluating multiple types of motors, switching to the automatic adjustment mode is performed each time a new motor is connected after each evaluation. When the process proceeds to step S102, the mode setting unit 210 sets the automatic adjustment mode in response to the reception of the mode setting signal MS indicating an instruction to set the automatic adjustment mode. After that, the control target of the microcomputer 43 is switched to the resolver gain adjuster 47, and the process proceeds to step S104.

[0041] In step S104, in accordance with the setting of the automatic adjustment mode, the motor rotation control unit 212 transmits three-phase command signals ucs, vcs, and wcs to the motor drive circuit 49 for controlling the electric motor 2 to energize through 120°, thereby driving the electric motor 2 to rotate through 360°. As a result, the signal value acquisition unit 214 acquires information on the signal values of various signals, and the acquired signal values are stored in a storage medium such as RAM. Then, the process proceeds to step S106.

[0042] 6, in the automatic adjustment mode, a first excitation signal is output from the RDC 41, and this first excitation signal is input to the resolver 3 via the phase adjustment circuit 47b and the amplitude adjustment circuit 47c. In addition, this first excitation signal is also input to the A / D converter 47a. Furthermore, as shown in (2) in Figure 6, in response to the 360° rotation of the electric motor 2, a first sine wave signal and a first cosine wave signal are output from the resolver 3, and these first sine wave signal and first cosine wave signal are input to the RDC 41 and the A / D converter 47a, respectively. As a result, the A / D converter 47a outputs a digital second excitation signal and digital second sine wave signals and second cosine wave signals corresponding to the 360° rotation of the electric motor 2, and these signals are input to the microcomputer 43. In FIG. 6, reference numeral 31 denotes a buffer, two of which are provided in series on the output lines of the first sine wave signal and two of which are provided in series on the output lines of the first cosine wave signal.

[0043] In step S106, the phase difference calculation unit 216 calculates the phase differences α and α' between the first excitation signal and the first sine wave signal or the first cosine wave signal based on the signal value of the second excitation signal and the signal value of the second sine wave signal or the second cosine wave signal. Thereafter, the calculation results are stored in a storage medium such as a RAM, and the process proceeds to step S108.

[0044] Here, the phase difference is calculated based on the time information of the signal values of the zero-crossing points of each signal. Specifically, the phase difference is calculated from the following equation (5) using the time information when the voltage values of the first excitation signal and the first sine wave signal or the first cosine wave signal become 0. The time information may be, for example, time information, or if the sampling period is known, information on the time interval can be determined from the period. Phase difference = (phase shift / period) × 360° (5)

[0045] The example shown in Figure 7 shows the phase difference between the first excitation signal (exc) and the first sine wave signal or first cosine wave signal (Vout). As shown in Figure 7, the zero-cross time t2 of the first excitation signal is 50 μs, and the zero-cross time t1 of the first sine wave signal or first cosine wave signal is 40 μs. Therefore, the phase shift is "t2 - t1 = 50 μs - 40 μs = 10 μs." Furthermore, since the time of one cycle of the first excitation signal is 100 μs, the phase difference can be calculated from equation (5) above as "phase difference = (10 μs / 100 μs) × 360° = 36°."

[0046] In step S108, the peak-to-peak value calculation unit 218 calculates the PP values pp and pp' of the first sine wave signal or the first cosine wave signal based on the minimum and maximum signal values of the second sine wave signal or the second cosine wave signal. Thereafter, the calculation results are stored in a storage medium such as RAM, and the process proceeds to step S110. Specifically, it is calculated as "PP value = maximum value - minimum value." Since the minimum value is a negative voltage value, the PP value is calculated by adding the absolute values of both.

[0047] In step S110, the phase gain adjuster 220 and the amplitude gain adjuster 222 determine whether the calculated phase differences α and α' and the PP values pp and pp' are within the ranges of the specifications for the RDC 41. If it is determined that both the phase difference and the PP value are within the ranges (Yes), the currently set values of the ladder resistors Rd1, Rd2, and Rd3 of the first DP 471, the second DP 472, and the third DP 473 are stored in a non-volatile storage medium such as an EEPROM. Then, the series of processes ends. On the other hand, if it is determined that either or both of the phase difference and the PP value are not within the ranges of the specifications (No), the process proceeds to step S112.

[0048] When the process proceeds to step S112, the value of at least one of the ladder resistors Rd1, Rd2, and Rd3 is calculated to adjust at least one of the phase gain and amplitude gain for adjusting the phase and amplitude of the first excitation signal, and then the process proceeds to step S114. Below, specific numerical examples will be given to explain examples of calculating the values of the ladder resistors Rd1, Rd2, and Rd3 that adjust the phase gain and amplitude gain so that the phase difference and PP value fall within the standard range.

[0049] The conditions for the RDC 41 are as follows: the specified range of the phase difference between the first excitation signal and the first sine wave signal or the first cosine wave signal is 0°±44°; the specified range of the amplitude of the first sine wave signal or the first cosine wave signal is 3.15 Vpp±27% (range 2.3 to 4.0 Vpp) in P-P value; the amplitude of the first excitation signal is 7.2 Vpp; and the excitation frequency is 10 kHz.

[0050] The conditions for the first DP471, second DP472, and third DP473 are a 10-bit resolution (0 to 1023) and a terminal-to-terminal resistance of 10 kΩ. Under these conditions, if the first DP471, second DP472, and third DP473 use values in the range of 200 to 1023 bits, the values of the ladder resistors Rd1, Rd2, and Rd3 can be adjusted in the range of 1,953.2 Ω to 9,990.6 Ω. The resistance per LSB is 9.766 Ω.

[0051] Furthermore, for the first DP 471 of the phase adjustment circuit 47b, the value of the capacitor C1 is set to 1500 pF. Because the excitation frequency (f) is 10 kHz, ω(2πf) = 62,832 Rad / s. Furthermore, if the value of the ladder resistor Rd1 is 1,953.2 Ω, then "phase = -0.36 rad" is obtained from equation (1) above. If the value is 9,990.6 Ω, then "phase = -1.51 rad" is obtained. Converting these units to degrees yields "-20.86°" and "-86.55°," respectively. This allows the phase to be adjusted within a range of approximately 65.69°. Furthermore, the initial value of the amplitude gain of the amplitude adjustment circuit 47c is set to 0.5. In this case, the first excitation signal of 7.2 [Vpp] input to the amplitude adjustment circuit 47c is output as a first excitation signal of 3.6 [Vpp].

[0052] Furthermore, if the initial value of the amplitude gain (Rd3 / Rd2) is "0.5", the initial value of the ladder resistor Rd2 will be, for example, "4,883 [Ω] (9.766 [Ω] x 500)", and the initial value of the ladder resistor Rd3 will be, for example, "2,441.5 [Ω] (9.766 [Ω] x 250)".

[0053] Now, as shown in Figure 8(a), let us assume that the phase difference between the first excitation signal and the first sine wave signal or the first cosine wave signal is 47.1°. Also, let us assume that the amplitude of the first sine wave signal or the first cosine wave signal is 2.2 Vpp. In other words, let us assume that the difference between the first excitation signal and the first sine wave signal or the first cosine wave signal is approximately 0.6 times. The phase difference of 47.1° between the first excitation signal and the first sine wave signal or the first cosine wave signal is outside the specified range of the phase difference, that is, it is 3.1° larger than the specified range of 0°±44°.

[0054] Furthermore, if the amplitude of the first sine wave signal or the first cosine wave signal input to the RDC 41 after passing through the resolver 3 is 2.2 [Vpp], it is not within the amplitude specification range. In other words, it is 0.95 [Vpp] short of the specification value of 3.15 [Vpp]. Therefore, both the phase gain and the amplitude gain need to be adjusted. Regarding the phase gain, the value of the ladder resistor Rd1 is determined so that the phase is adjusted to a maximum of 65.69°, for example.

[0055] As for the amplitude gain, the first excitation signal that has passed through the amplitude adjustment circuit 47c passes through the resolver 3 and is multiplied by 0.6, and then the amplitude gain should be approximately 3.15 [Vpp]. Therefore, the values of the ladder resistors Rd2 and Rd3 should be determined so that the amplitude gain (Rd3 / Rd2) is, for example, 0.715. In this case, the value of ladder resistor Rd2 is determined to be "3,906 [Ω] (9.766 [Ω] x 400)" and the value of ladder resistor Rd3 is determined to be "2,793.1 [Ω] (9.766 [Ω] x 286)". In step S114, at least one of the phase gain and the amplitude gain is adjusted based on the resistance values calculated in step S112, and the process proceeds to step S116.

[0056] Specifically, as shown in (4) of Fig. 9, command signals pgc and pgc' for changing the value of ladder resistor Rd1 to the calculated resistance value are sent to the first DPs 471 of one and the other of the two phase adjustment circuits 470b, respectively. In addition, as shown in (4) of Fig. 9, command signals agc1 and agc1' for changing the value of ladder resistor Rd2 to the calculated resistance value are sent to the second DPs 472 of one and the other of the two amplitude adjustment circuits 470c, respectively. Furthermore, command signals agc2 and agc2' for changing the value of ladder resistor Rd3 to the calculated resistance value are sent to the third DPs 473 of one and the other of the two amplitude adjustment circuits 470c, respectively. In the above numerical example, phase adjustment circuit 47b can perform phase adjustment of up to 65.69°, and amplitude adjustment circuit 47c can adjust the amplitude gain in the range of approximately 0.20 to 5.11.

[0057] In step S116, the motor rotation control unit 212 transmits three-phase command signals ucs, vcs, and wcs to the motor drive circuit 49 for controlling the electric motor 2 to rotate 360°, thereby driving the electric motor 2 to rotate 360°. As a result, the signal value acquisition unit 214 acquires information on the signal values of various signals, and the acquired signal values are stored in a storage medium such as RAM. Then, the process proceeds to step S118.

[0058] In step S118, similarly to step S106, the phase difference calculation unit 216 calculates the phase differences α and α' between the first excitation signal and the first sine wave signal or the first cosine wave signal based on the signal value of the second excitation signal and the signal value of the second sine wave signal or the second cosine wave signal. Thereafter, the calculation results are stored in a storage medium such as RAM, and the process proceeds to step S120.

[0059] In step S120, similar to step S108, peak-to-peak value calculation unit 218 calculates the PP values pp and pp' of the first sine wave signal or the first cosine wave signal based on the minimum and maximum signal values of the second sine wave signal or the second cosine wave signal. Thereafter, the calculation results are stored in a storage medium such as RAM, and the process proceeds to step S122.

[0060] In step S122, the phase gain adjuster 220 and the amplitude gain adjuster 222 determine whether the calculated phase difference and PP value are within the range of the standard value of the RDC 41. If it is determined that both the phase difference and the PP value are within the range (Yes), the process proceeds to step S124. Then, the series of processes ends. On the other hand, if it is determined that either or both of the phase difference and the PP value are not within the range of the standard value (No), the process proceeds to step S112.

[0061] In the above numerical example, as shown in FIG. 8(b), the phase difference can be adjusted up to 18.6°. If the phase difference is 18.6°, the result falls within the range of the phase specification of the RDC 41. However, in the above numerical example, the phase difference can also be adjusted to 0°. In addition, in the above numerical example, the amplitude gain of the amplitude adjustment circuit 47c is approximately 0.715, and the first excitation signal passing through the amplitude adjustment circuit 47c is 5.148 Vpp. As a result, the resolver 3 outputs a first sine wave signal and a first cosine wave signal of approximately 3.15 Vpp. Therefore, the calculated PP values pp and pp' fall within the range of the amplitude specification of the RDC 41. If the process proceeds to step S124, the values of the ladder resistors Rd1, Rd2, and Rd3 after adjustment of the first DP 471, the second DP 472, and the third DP 473 are stored in a nonvolatile storage medium such as an EEPROM, etc. After that, the series of processes ends.

[0062] [Motor operation processing] Next, the motor operation process executed by the microcomputer 43 of the motor control device 4 will be described. Fig. 10 is a flowchart showing the motor operation process, and Fig. 11 is a diagram showing the signal flow when the motor operation mode is set. The CPU of the microcomputer 43 starts a control program stored in a predetermined area of the ROM, and executes the motor operation process shown in the flowchart of FIG. 10 in accordance with the program. When the motor operation process is executed by the CPU, as shown in FIG. 10, the process first proceeds to step S200.

[0063] In step S200, the mode setting unit 210 determines whether or not it has received a mode setting signal MS from the switch 45, indicating an instruction to set the motor operation mode. If it determines that the signal has been received (Yes), the motor operation mode is set and the process proceeds to step S202. On the other hand, if it determines that the signal has not been received (No), the determination process is repeated until the signal is received. When the process proceeds to step S202, the gain setting unit 224 reads out the adjusted values of the ladder resistors Rd1, Rd2, and Rd3 from a nonvolatile storage medium such as an EEPROM included in the first DP 471, the second DP 472, and the third DP 473. After that, the process proceeds to step S204.

[0064] In step S204, the gain setting unit 224 transmits command signals pgc and pgc' to the first DPs 471 of one and the other of the two phase adjustment circuit units 470b based on the read value of ladder resistor Rd1. In addition, command signals agc1 and agc2, and agc1' and agc2' to the second DPs 472 and the third DPs 473 of one and the other of the two amplitude adjustment circuit units 470c based on the read values of ladder resistors Rd2 and Rd3. Then, the process proceeds to step S206. As a result, the values of the ladder resistors Rd1, Rd2, and Rd3 of the two phase adjustment circuit sections 470b and the two amplitude adjustment circuit sections 470c are set to the adjusted values, and the phase gain and amplitude gain are adjusted. In step S206, the motor operation control unit 226 switches the circuit to be controlled to the circuit for motor operation, and the process proceeds to step S208. Here, the motor operation circuit is the circuit portion of the motor control device 4 excluding the A / D converter 47a. After switching, the operation of the A / D converter 47a may be stopped (power supply may be stopped), thereby reducing power consumption.

[0065] In step S208, the motor operation control unit 226 calculates the rotation angle θ and rotation speed ω of the electric motor 2 based on the angle signal φ input from the RDC 41. Then, based on the calculated rotation angle θ and rotation speed ω, a motor operation control process is executed to control the operation of the electric motor 2. Then, the process proceeds to step S210. Here, in the motor operation mode, as shown in (1) in Figure 11, a first excitation signal is output from the RDC 41, and this first excitation signal is input to the resolver 3 via the phase adjustment circuit 47b and the amplitude adjustment circuit 47c. 11(2), a first sine wave signal and a first cosine wave signal are output from the resolver 3, and these first sine wave signal and first cosine wave signal are respectively input to the RDC 41. As a result, the RDC 41 generates a digital angle signal φ. Furthermore, as shown in (3) in Fig. 11, an angle signal φ is output from the RDC 41 and input to the microcomputer 43. The microcomputer 43 calculates the rotation angle θ and rotation speed ω of the electric motor 2 based on the input angle signal φ. Furthermore, three-phase command signals ucs, vcs, and wcs for driving the electric motor 2 are generated based on the rotation angle θ and rotation speed ω. Then, as shown in (4) in FIG. 11, three-phase command signals ucs, vcs, and wcs are output from the microcomputer 43, and these command signals are input to the motor drive circuit 49. As a result, based on the input command signal, the motor drive circuit 49 outputs a three-phase AC signal to the electric motor 2 for driving the electric motor 2. As a result, the motor rotor of the electric motor 2 is driven to rotate, and the motor rotary shaft is driven to rotate. In step S210, the motor operation control unit 226 determines whether or not an instruction to end the operation of the electric motor 2 has been received. If it is determined that an instruction has been received (Yes), the series of processes ends; if it is determined that an instruction has not been received (No), the process proceeds to step S208.

[0066] (Effects of the embodiment) As described above, the motor device 1 of this embodiment includes the electric motor 2, the one-phase excitation, two-phase output resolver 3, and the motor control device 4. The motor control device 4 includes the RDC 41, the microcomputer 43, the switch 45, the resolver gain adjuster 47, and the motor drive circuit 49.

[0067] The resolver gain adjustment device 47 includes a microcomputer 43 shared with the motor control device 4, and an A / D converter 47a that performs A / D conversion on the first excitation signal output from the RDC 41 and the first sine wave signal and first cosine wave signal output from the resolver 3. In addition, the resolver gain adjustment device 47 includes a phase adjustment circuit 47b that adjusts the phase of the first excitation signal, and an amplitude adjustment circuit 47c that adjusts the amplitude of the first excitation signal. The phase adjustment circuit 47b includes two phase adjustment circuit sections 470b, and each phase adjustment circuit section 470b includes an operational amplifier OP1 and a first DP 471 for adjusting the phase gain. Furthermore, the amplitude adjustment circuit 47c includes two amplitude adjustment circuit sections 470c, and each amplitude adjustment circuit section 470c includes an operational amplifier OP2, and a second DP 472 and a third DP 473 for adjusting the amplitude gain.

[0068] The microcomputer 43 acquires the digital signal values of the second excitation signal, the second sine wave signal, and the second cosine wave signal input from the A / D converter 47a when the electric motor 2 is rotated 360° or more. Furthermore, based on each acquired signal value, the microcomputer 43 calculates the phase difference between the first excitation signal and the first sine wave signal or the first cosine wave signal. The phase gain of the phase adjustment circuit 47b is then adjusted by adjusting the value of the ladder resistor Rd1 of the first DP 471 so that this phase difference falls within the specified range of the phase difference of the RDC 41.

[0069] In addition, the microcomputer 43 calculates a PP value based on the acquired digital second sine wave signal and second cosine wave signal, and adjusts the amplitude gain of the amplitude adjustment circuit 47c by adjusting the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 so that the PP value falls within the specified range of the amplitude (PP value) of the RDC 41.

[0070] With this configuration, the microcomputer 43 can automatically adjust the value of the ladder resistor Rd1 of the first DP 471 so that the phase difference between the first excitation signal and the first sine wave signal or the first cosine wave signal falls within the specified range of the phase difference of the RDC 41. In addition, the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 can be automatically adjusted so that the P-P value of the first sine wave signal or the first cosine wave signal falls within the specified range of the amplitude of the RDC 41. As a result, it is possible to avoid the hassle of manual adjustment each time the resolver connected to the RDC 41 is replaced with a different type of resolver or a new resolver is connected.

[0071] For example, when performing performance tests on multiple types of motors, the values of the ladder resistors Rd1 to Rd3 of the first to third DPs 471 to 473 can be automatically adjusted each time the motor is replaced so that each signal falls within the specification range of the RDC 41. This allows for efficient performance tests on multiple types of motors. Furthermore, in the motor device 1 of this embodiment, the microcomputer 43 calculates the phase difference based on time information of the zero cross points of the second excitation signal and the second sine wave signal or the second cosine wave signal. With this configuration, the phase difference can be easily calculated from the signal value at the zero cross point. Furthermore, in the motor device 1 of this embodiment, the microcomputer 43 and the motor drive circuit 49 are configured to rotate the electric motor 2 360° by energization control using back electromotive force.

[0072] With this configuration, the electric motor 2 can be rotated automatically, eliminating the need to rotate the electric motor 2 manually or with an external device. As a result, it is possible to reduce the effort required for rotation manually or with an external device, and the increased costs associated with using an external device. Furthermore, the motor device 1 of this embodiment is configured to store in a nonvolatile storage medium such as an EEPROM the value of the ladder resistor R1 of the first DP 471 after the phase difference has been adjusted to fall within the specification range of the RDC 41. Additionally, the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 after the peak-to-peak value has been adjusted to fall within the specification range of the RDC 41 are stored in a nonvolatile storage medium such as an EEPROM.

[0073] With this configuration, the adjusted values can be recorded, so that the recorded values can be reused, for example, when a resolver of the same model number is connected. As a result, it is possible to use the values as the initial values in the automatic adjustment mode or to omit some of the processing in the automatic adjustment mode. Furthermore, in the motor operation mode, the values of the ladder resistors Rd1, Rd2, and Rd3, which were initialized by turning off the power, can be easily set to the adjusted values.

[0074] (Correspondence) In this embodiment, the second DP 472 and the third DP 473 correspond to the second digital potentiometer, the microcomputer 43 corresponds to the control unit, and the A / D converter 47a corresponds to the first A / D converter and the second A / D converter. In this embodiment, the mode setting unit 210 and step S100 correspond to the mode setting unit, and the motor rotation control unit 212 and step S104 correspond to the motor rotation control unit.

[0075] In addition, in this embodiment, the signal value acquisition unit 214 and step S104 correspond to the signal value acquisition unit, the phase difference calculation unit 216 and step S106 correspond to the phase difference calculation unit, and the peak-peak value calculation unit 218 and step S108 correspond to the peak-peak value calculation unit.

[0076] In addition, in this embodiment, the phase gain adjustment unit 220 and steps S112 and S114 correspond to the phase gain adjustment unit, the amplitude gain adjustment unit 222 and steps S112 and S114 correspond to the amplitude gain adjustment unit, and the motor operation control unit 226 and step S208 correspond to the motor operation control unit. In this embodiment, the value of the ladder resistor Rd1 of the first DP 471 corresponds to the value of the first digital potentiometer, and the values of the ladder resistors Rd2 and Rd3 of the second DP 472 and the third DP 473 correspond to the value of the second digital potentiometer.

[0077] (Variation) In the above embodiment, the values of the ladder resistors Rd1, Rd2, and Rd3 of the first DP 471, the second DP 472, and the third DP 473 are adjusted to adjust the phase and amplitude of the first excitation signal, but this is not limiting. For example, the phase and amplitude of the first sine wave signal and the first cosine wave signal output from the resolver 3 may be adjusted. A specific example will be described below.

[0078] FIG. 12 is a block diagram showing the configuration of a motor device 1A according to a modified example. The motor device 1A has a configuration in which the phase adjustment circuit 47b and the amplitude adjustment circuit 47c of the motor device 1 of the above embodiment are replaced with a phase adjustment circuit 47d and an amplitude adjustment circuit 47e. The phase adjustment circuit 47d is a circuit that adjusts the phases of the first sine wave signal and the first cosine wave signal output from the resolver 3, and has a configuration similar to that of the phase adjustment circuit 47b in the first embodiment. However, since the first sine wave signal and the first cosine wave signal are differential signals, the number of phase adjustment circuit units 470b is doubled to four. The amplitude adjustment circuit 47e is a circuit that adjusts the amplitudes of the first sine wave signal and the first cosine wave signal that have passed through the phase adjustment circuit 47d, and has a configuration similar to that of the amplitude adjustment circuit 47c in the first embodiment. However, because the first sine wave signal and the first cosine wave signal are differential signals, the number of amplitude adjustment circuit sections 470c is doubled to four.

[0079] That is, instead of adjusting the phase and amplitude of the first excitation signal, the phase and amplitude of the first sine wave signal and the first cosine wave signal are adjusted to adjust the phase difference with the first excitation signal and the PP values of the first sine wave signal and the first cosine wave signal to fall within the specification range of RDC41. With this configuration, it is possible to obtain the same functions and effects as the motor device 1 of the above embodiment. Note that a configuration may be adopted in which a phase adjustment circuit 47d and an amplitude adjustment circuit 47e are added to the resolver gain adjustment device 47 of the above embodiment. With this configuration, in addition to adjusting the phase and amplitude of the first excitation signal by the phase adjustment circuit 47b and the amplitude adjustment circuit 47c, the phase adjustment circuit 47d and the amplitude adjustment circuit 47e can adjust the phase and amplitude of the first sine wave signal and the first cosine wave signal. In this case, one of the signals may be set to a fixed value and the other may be adjusted.

[0080] In the above embodiment and its modified examples, the motor control device 4 and the resolver gain adjustment device 47 share the same microcomputer 43. However, the present invention is not limited to this configuration, and the microcomputer for gain adjustment and the microcomputer for motor operation control may be configured as separate microcomputers. In this case, a personal computer may be used as the microcomputer for gain adjustment. This makes it easier to modify and improve the control program.

[0081] In the above embodiment and its modified examples, the electric motor 2 is automatically rotated 360° by the motor rotation control unit 212, which is a functional block of the microcomputer 43, but this is not the only possible configuration. For example, other configurations may be used, such as a configuration in which the electric motor 2 is rotated 360° mechanically by an external device or a configuration in which the electric motor 2 is rotated 360° manually.

[0082] Furthermore, in the above embodiment and its modified examples, the switch 45 is used to switch between the automatic adjustment mode and the motor operation mode. However, this configuration is not limited to this. For example, the model number and unique identification information of the connected resolver are acquired and stored in a non-volatile storage medium. Furthermore, if the resolver is replaced due to a malfunction or replaced with another motor (another resolver), the stored model number and identification information are compared with the model number and identification information of the connected resolver. If it is determined that a different resolver has been connected, the automatic adjustment mode may be set. In this case, if a resolver with the same model number but different identification information is connected, the adjusted ladder resistor value of the same model number may be set as the initial value. Furthermore, in the above embodiment and its modified examples, the electric motor 2 is described as a three-phase brushless motor, but the configuration is not limited to this, and other motors to which a resolver, such as a stepping motor, can be used.

[0083] In the above embodiment and its modified examples, both of the two resistors that determine the amplitude gain of the amplitude adjustment circuit section 470c are configured as digital potentiometers, but the present invention is not limited to this configuration. One of the two resistors may be configured as a digital potentiometer, and the other may be configured as a fixed resistance element. In the above embodiment and its modified examples, the functions of the components of the functional blocks shown in Fig. 4 are realized by a CPU executing a program (software), but this is not a limitation. The functions of one or more components of the functional blocks may be realized by hardware such as an electric circuit or an electronic circuit. [Explanation of symbols]

[0084] 1,1A...motor device, 2...electric motor, 3...resolver, 4...motor control device, 31...buffer, 41...RDC, 43...microcomputer, 45...switch, 47...resolver gain adjustment device, 47a...A / D converter, 47b...phase adjustment circuit, 47c...amplitude adjustment circuit, 49...motor drive circuit, 210...mode setting unit, 212...motor rotation control unit, 214...signal value acquisition unit, 216...phase difference calculation unit, 218...peak-to-peak value calculation unit, 220...phase gain adjustment unit, 222...amplitude gain adjustment unit, 224...gain setting unit, 226...motor operation control unit, 471...first digital potentiometer, 472...second digital potentiometer, 473...third digital potentiometer, Rd1, Rd2, Rd3...ladder resistors, C1...capacitor, OP1, OP2...operational amplifier

Claims

1. a phase adjustment circuit including a first amplifier for adjusting the phase of an excitation signal output from a resolver digital converter or an electrical signal output from a resolver attached to a rotating shaft of a motor and excited by the excitation signal, and a first digital potentiometer for adjusting a gain of the first amplifier; an amplitude adjustment circuit including a second amplifier for adjusting the amplitude of the excitation signal or the electrical signal and a second digital potentiometer for adjusting the gain of the second amplifier; a signal acquisition unit that acquires the excitation signal and the electrical signal corresponding to a rotation of the motor of 360° or more; a phase difference calculation unit that calculates a phase difference between the excitation signal and the electrical signal based on the excitation signal and the electrical signal acquired by the signal acquisition unit; a peak-to-peak value calculation unit that calculates a peak-to-peak value of the electrical signal based on the electrical signal acquired by the signal acquisition unit; a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the resolver-to-digital converter; an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit is within a specification range of the peak-to-peak value of the resolver digital converter.

2. a first A / D converter that converts an analog first excitation signal output from the resolver digital converter into a digital second excitation signal and outputs the digital second excitation signal; a second A / D converter that converts a first analog electrical signal output from a resolver attached to a rotating shaft of the motor and excited by the first excitation signal into a second digital electrical signal and outputs the second digital electrical signal; a phase adjustment circuit including a first amplifier for adjusting the phase of the first excitation signal or the first electrical signal, and a first digital potentiometer for adjusting a gain of the first amplifier; an amplitude adjustment circuit including a second amplifier for adjusting the amplitude of the first excitation signal or the first electrical signal, and a second digital potentiometer for adjusting a gain of the second amplifier; a control unit, The control unit a signal value acquiring unit that acquires signal values of the second excitation signal and the second electrical signal output from the first A / D converter and the second A / D converter in response to rotation of the motor of 360° or more; a phase difference calculation unit that calculates a phase difference between the second excitation signal and the second electrical signal based on the signal value of the second excitation signal and the signal value of the second electrical signal acquired by the signal value acquisition unit; a peak-to-peak value calculation unit that calculates a peak-to-peak value of the second electrical signal based on the signal value of the second electrical signal acquired by the signal value acquisition unit; a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the resolver-to-digital converter; an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit is within a specification range of the peak-to-peak value of the resolver digital converter.

3. In claim 2, the first excitation signal is a one-phase or two-phase excitation signal; the resolver is a one-phase or two-phase excitation and two-phase output type resolver, The resolver gain adjustment device, wherein the first electric signal output from the resolver is a two-phase electric signal.

4. In claim 2, The phase difference calculation means calculates the phase difference based on time information of zero cross points of the second excitation signal and the second electrical signal.

5. In claim 2, A resolver gain adjustment device including a motor rotation control unit that rotates the motor by 360 degrees or more by energization control using back electromotive force.

6. In claim 2, The control unit includes a recording unit that records, on a recording medium, the value of the first digital potentiometer after adjusting the phase difference to fall within the specification range and the value of the second digital potentiometer after adjusting the peak-to-peak value to fall within the specification range.

7. a resolver-to-digital converter that outputs a first analog excitation signal that excites a resolver attached to a rotary shaft of the motor, and that outputs a digital angle signal corresponding to the rotational position of the motor based on the first analog electrical signal output from the resolver; a first A / D converter that converts the first excitation signal output from the resolver digital converter into a digital second excitation signal and outputs the digital second excitation signal; a second A / D converter that converts the first electrical signal output from the resolver into a digital second electrical signal and outputs the digital second electrical signal; a phase adjustment circuit including a first amplifier for adjusting the phase of the first excitation signal or the first electrical signal, and a first digital potentiometer for adjusting a first gain of the first amplifier; an amplitude adjustment circuit including a second amplifier for adjusting the amplitude of the first excitation signal or the first electrical signal, and a second digital potentiometer for adjusting a second gain of the second amplifier; a control unit, The control unit a mode setting unit that sets an automatic adjustment mode in response to an input of a setting instruction signal for an automatic adjustment mode in which the first gain and the second gain are automatically adjusted, and that sets the motor operation mode in response to an input of a setting instruction signal for a motor operation mode in which operation of the motor is controlled; a signal value acquiring unit that acquires values of the second excitation signal and the second electrical signal output from the first A / D converter and the second A / D converter in response to rotation of the motor of 360° or more in accordance with the setting of the automatic adjustment mode; a phase difference calculation unit that calculates a phase difference between the second excitation signal and the second electric signal based on the values of the second excitation signal and the second electric signal acquired by the signal value acquisition unit; a peak-to-peak value calculation unit that calculates a peak-to-peak value of the second electrical signal based on the value of the second electrical signal acquired by the signal value acquisition unit; a phase gain adjustment unit that adjusts the value of the first digital potentiometer so that the phase difference calculated by the phase difference calculation unit falls within a specification range of the phase difference of the resolver-to-digital converter; an amplitude gain adjustment unit that adjusts the value of the second digital potentiometer so that the peak-to-peak value calculated by the peak-to-peak value calculation unit falls within a specification range of the peak-to-peak value of the resolver-to-digital converter; a motor operation control unit that controls operation of the motor based on the angle signal output from the resolver-to-digital converter in accordance with the setting of the motor operation mode.

8. A motor device comprising: a motor; a resolver attached to a rotary shaft of the motor; and the motor control device according to claim 7.

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