Resolver signal abnormality detection circuit and angle detection device

Abstract

An abnormality in a two-phase resolver signal is detected by a circuit smaller than two systems of abnormality detection means for a two-phase resolver signal. [Solution] The resolver signal abnormality detection circuit 140 is a circuit that detects abnormalities in two-phase resolver signals output from a resolver, and includes a combined signal generation unit 141 that combines the two-phase resolver signals to generate a combined resolver signal, a threshold holding unit 142 that holds a threshold value, and a comparison judgment unit 143 that compares the combined resolver signal with the threshold value and judges the presence or absence of an abnormality based on the comparison result. The threshold holding unit 142 holds a value in the range from the first amplitude value to the second amplitude value as a threshold value, where the amplitude of the two-phase resolver signals when normal is set to a first amplitude value, and the amplitude of the normal combined resolver signal that is combined when the two-phase resolver signals are normal is set to a second amplitude value, and the comparison judgment unit 143 judges that there is an abnormality when the amplitude of the combined resolver signal is smaller than the threshold value.

Description

[Technical field]

[0001] The present invention relates to a resolver signal abnormality detection circuit and an angle detection device, and more particularly to a new improvement for detecting an abnormality in a resolver signal in an angle detection device using a two-phase excitation / two-phase output phase modulation type resolver. [Background technology]

[0002] In an angle detection device using a resolver of a two-phase excitation / two-phase output phase modulation type, it has been proposed to detect an abnormality in a resolver signal caused by a break in the resolver, etc. As a circuit for detecting an abnormality in a resolver signal of this kind, for example, the configuration shown in Patent Document 1 can be given. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2016-105047 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration of this type of angle detection device is shown in Fig. 10. Fig. 10 is a diagram showing the configuration of a conventional angle detection device 20. The angle detection device 20 detects the angle of rotation of a phase modulation type resolver 10, and mainly includes an excitation unit 21, a resolver / digital conversion circuit 22, and a resolver signal abnormality detection circuit 23. The resolver signal abnormality detection circuit 23 includes a threshold value holding unit 23a, a first comparison and judgment unit 23b, and a second comparison and judgment unit 23c.

[0005] Here, the first comparison and judgment unit 23b uses the threshold value from the threshold value holding unit 23a to detect an abnormality in the first resolver signal output from the resolver 10. When the first comparison and judgment unit 23b detects an abnormality, it outputs a first abnormality judgment signal Err. Similarly, the second comparison and judgment unit 23c uses the threshold value from the threshold value holding unit 23a to detect an abnormality in the second resolver signal output from the resolver 10. When the second comparison and judgment unit 23c detects an abnormality, it outputs a second abnormality judgment signal Err. In this case, in order to detect an abnormality in each of the two-phase resolver signals, it was necessary to provide the first comparison and determination unit 23b and the second comparison and determination unit 23c as two systems of abnormality detection means, which resulted in a problem of an increase in the number of circuit elements and the circuit size.

[0006] For this reason, it has been desired to realize a circuit that is smaller than the two-system abnormality detection means for the two-phase resolver signals and to realize an angle detection device equipped with such an abnormality detection circuit. In order to solve the above problems, the present invention aims to provide a resolver signal abnormality detection circuit and an angle detection device that are capable of detecting abnormalities in two-phase resolver signals using a circuit that is smaller than two-system abnormality detection means for two-phase resolver signals. [Means for solving the problem]

[0007] A resolver signal abnormality detection circuit according to the present invention is a resolver signal abnormality detection circuit that detects an abnormality in a two-phase resolver signal output from a resolver, the resolver signal abnormality detection circuit including: a composite signal generation unit that generates a composite resolver signal by combining the two-phase resolver signals; Positive side No. 1 Threshold and the second negative threshold A threshold value holding unit holds the synthesized resolver signal. No. 1 Threshold and the second threshold and a comparison and determination unit for determining whether or not there is an abnormality based on a result of the comparison. Maximum positive value of Positive side No. 1 signal The normal combined resolver signal is calculated by dividing the normal combined resolver signal by the value of Maximum positive value of Positive side Second signal If the value is Positive side No. 1 signal Beyond Value Positive side Second signal Values ​​in the range up to No. 1 Hold as threshold, a maximum negative value of the two-phase resolver signals under normal conditions is defined as a first negative signal value, a maximum negative value of a combined resolver signal under normal conditions that is combined with the two-phase resolver signals under normal conditions is defined as a second negative signal value, and when the absolute value of the second negative signal value is greater than the absolute value of the first negative signal value, a value in the range from the first negative signal value to the second negative signal value is held as a second threshold value; The comparison and determination unit compares the combined resolver signal Maximum but The first and second thresholds If it is smaller than the threshold, it is determined to be abnormal.

[0008] The angle detection device of the present invention is an angle detection device that detects the rotation angle of a resolver, and includes an excitation unit that generates a two-phase excitation signal and supplies the excitation signal to the resolver, a resolver / digital conversion circuit that calculates the rotation angle of the resolver by processing the two-phase resolver signal output from the resolver, and a resolver signal abnormality detection circuit that detects an abnormality in the two-phase resolver signal output from the resolver.

[0009] In the resolver signal abnormality detection circuit according to the present invention, the comparison and determination unit compares a composite resolver signal No. 1 Threshold and the second threshold and a determination section that determines whether or not there is an abnormality based on a result of the comparison in the comparison section.

[0010] In the resolver signal abnormality detection circuit of the present invention, the threshold holding unit holds a first threshold on the positive side and a second threshold on the negative side as thresholds, and the comparison judgment unit has a window comparator that compares the composite resolver signal with the first threshold and the second threshold by the window comparator.

[0011] In the resolver signal abnormality detection circuit according to the present invention, the comparison and determination unit is Second signal value and a first threshold value, and the negative side of the combined resolver signal is Second signal value and a second threshold value, and the positive side of the combined resolver signal is Second signal value is smaller than the first threshold, and , the negative side of the composite resolver signal Second signal value is smaller than the first threshold value, it is determined that an abnormality has occurred.

[0012] In the resolver signal abnormality detection circuit according to the present invention, the composite signal generation unit generates a composite resolver signal by combining two-phase resolver signals by adding or subtracting them. Effect of the Invention

[0013] According to the present invention, it is possible to realize a resolver signal abnormality detection circuit and an angle detection device that are capable of detecting abnormalities in two-phase resolver signals using a circuit that is smaller than two-system abnormality detection means for two-phase resolver signals. [Brief description of the drawings]

[0014] [Figure 1] 1 is a configuration diagram showing a configuration of an angle detection device having a resolver signal abnormality detection circuit according to a first embodiment. [Diagram 2] 1 is a configuration diagram showing a configuration of a resolver signal abnormality detection circuit according to a first embodiment together with an angle detection device. [Diagram 3] 4 is a waveform diagram showing waveforms of two-phase resolver signals and a composite resolver signal waveform under normal conditions in the first embodiment. FIG. [Figure 4] 4 is a waveform diagram showing waveforms of two-phase resolver signals and a composite resolver signal waveform under normal conditions in the first embodiment. FIG. [Diagram 5] 4 is a waveform diagram showing waveforms of two-phase resolver signals in which only one phase is abnormal and a combined resolver signal waveform in the first embodiment. FIG. [Figure 6] 4 is a waveform diagram showing waveforms of two-phase resolver signals in which only one phase is abnormal and a combined resolver signal waveform in the first embodiment. FIG. [Figure 7] FIG. 11 is a configuration diagram showing the configuration of an angle detection device having a resolver signal abnormality detection circuit according to a second embodiment. [Figure 8] FIG. 11 is a waveform diagram showing waveforms of two-phase resolver signals in which only one phase is abnormal and a combined resolver signal waveform in the second embodiment. [Figure 9] FIG. 11 is a waveform diagram showing waveforms of two-phase resolver signals when both phases are abnormal and a combined resolver signal waveform in the second embodiment. [Figure 10]FIG. 1 is a diagram showing a configuration of a conventional resolver signal abnormality detection circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a resolver signal abnormality detection circuit and an angle detection device of the present invention will be described with reference to the drawings.

[0016] Embodiment 1 First, the resolver signal abnormality detection circuit and the angle detection device in the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a configuration diagram showing the configuration of an angle detection device 100 having a resolver signal abnormality detection circuit 140 in the first embodiment. Fig. 2 is a configuration diagram showing the configuration of the resolver signal abnormality detection circuit 140 in the first embodiment together with the angle detection device 100.

[0017] [Configuration of angle detection device 100] 1, the angle detection device 100 mainly includes a resolver / digital conversion circuit 110, a reference signal generation unit 120, an excitation unit 130, and a resolver signal abnormality detection circuit 140. The angle detection device 100 is connected to a two-phase excitation / two-phase output resolver 10 as a phase modulation type resolver. 2, the angle detection device 100 mainly includes a resolver / digital conversion circuit 110, a reference signal generation unit 120, and an excitation unit 130. The resolver signal abnormality detection circuit 140 exists outside the angle detection device 100. The resolver 10 is connected to the angle detection device 100 and the resolver signal abnormality detection circuit 140.

[0018] First, the detection of the rotation angle θ of the resolver 10 by the angle detection device 100 will be described separately for signal generation and angle detection. Then, the abnormality detection in the resolver signal abnormality detection circuit 140 will be described.

[0019] [Signal generation] The reference signal generating unit 120 generates a reference signal ωt representing a time reference corresponding to a predetermined reference frequency ω. The reference signal generating unit 120 supplies the reference signal ωt to the resolver / digital conversion circuit 110 and the excitation unit 130.

[0020] The excitation unit 130 generates a first excitation signal having a sinωt component and a second excitation signal having a cosωt component as orthogonal two-phase excitation signals based on the reference signal ωt supplied from the reference signal generation unit 120. The excitation unit 130 supplies the generated first excitation signal and second excitation signal to the excitation winding of the resolver 10. Hereinafter, the first excitation signal and the second excitation signal are referred to as "two-phase excitation signals."

[0021] [Angle detection] When orthogonal two-phase excitation, two-phase output, phase modulation type resolver 10 is supplied with two-phase excitation signals from excitation unit 130, it detects the magnetic flux generated by these excitation signals using a detection winding and outputs a two-phase phase-modulated analog signal having a phase corresponding to the rotation angle θ. Hereinafter, the two-phase phase-modulated analog signal having a phase corresponding to the rotation angle θ will be referred to as a "two-phase resolver signal." The two-phase resolver signal has a phase corresponding to the rotation angle θ, and can be expressed as a first resolver signal sin(ωt-θ) and a second resolver signal cos(ωt-θ). The resolver / digital conversion circuit 110 processes the two-phase resolver signal output from the resolver 10 using the reference signal ωt from the reference signal generation unit 120 to calculate the rotation angle θ of the resolver 10 and output detection angle data φ corresponding to the rotation angle θ. Note that the calculation of the rotation angle θ and the output of the detection angle data φ in the resolver / digital conversion circuit 110 are known, and therefore detailed description will be omitted.

[0022] [Anomaly Detection] The resolver signal abnormality detection circuit 140 includes a composite signal generation unit 141, a threshold value holding unit 142, and a comparison and determination unit 143. The comparison and determination unit 143 includes a comparison unit 143a and a determination unit 143b. Here, abnormality detection by the resolver signal abnormality detection circuit 140 will be described with reference to Fig. 3 to Fig. 6. Fig. 3 and Fig. 4 are waveform diagrams showing waveforms of two-phase resolver signals and a combined resolver signal waveform in normal conditions in the first embodiment. Fig. 5 and Fig. 6 are waveform diagrams showing waveforms of two-phase resolver signals and a combined resolver signal waveform when only one phase is abnormal in the first embodiment. 3 to 6, the horizontal axis indicates time t [s], and the vertical axis indicates the maximum normal value of the two-phase resolver signal. Signal Value is shown as a signal value normalized to 1.0, the first resolver signal is shown by a dashed dotted line, the second resolver signal is shown by a dashed dotted line, and the composite resolver signal is shown by a dotted line. In the following explanation, the waveform Signal Value A small value means that the value is close to 0 regardless of whether it is positive or negative. Signal Value A large value means a value far from 0, regardless of whether it is positive or negative.

[0023] The first resolver signal sin(ωt-θ) and the second resolver signal cos(ωt-θ) from the resolver 10 are supplied to the composite signal generating unit 141 as two-phase resolver signals. The composite signal generating unit 141 generates a composite resolver signal by adding or subtracting the two-phase resolver signals. Fig. 3 shows how normal two-phase resolver signals are added to generate a normal composite resolver signal √2sin(ωt-θ+45°). 4 shows how a normal combined resolver signal √2sin(ωt-θ+135°) is generated by subtracting the second resolver signal from the first resolver signal in a normal two-phase resolver signal. Although not shown, when a normal two-phase resolver signal is used, a normal combined resolver signal √2sin(ωt-θ-45°) is obtained by subtracting the first resolver signal from the second resolver signal.

[0024] The threshold value holding unit 142 holds the normal two-phase resolver signals. Maximum positive value of Positive side No. 1 signal The normal combined resolver signal is calculated by dividing the normal combined resolver signal by the value of Maximum positive value of Positive side Second signal If the value is Positive side No. 1 signal Beyond Value Positive side Second signal Values ​​in the range up to No. 1 Keep as Threshold The maximum negative value of the two-phase resolver signals when normal is set as a negative first signal value, the maximum negative value of a combined resolver signal when normal, which is combined with the two-phase resolver signals when normal, is set as a negative second signal value, and when the absolute value of the negative second signal value is greater than the absolute value of the negative first signal value, a value in the range from the negative first signal value to the negative second signal value is held as a second threshold value. Specifically, the threshold value holder 142 holds a first threshold value Th1 on the positive side and a second threshold value Th2 on the negative side as the above threshold values. In the example shown in Figure 3 and Figure 4, the normal two-phase resolver signal Maximum 1.0 The positive first signal value and death, -1.0 The negative side No. 1 signal The normal combined resolver signal is calculated by dividing the normal combined resolver signal by the value of Maximum 1.4 The positive second signal value and death, -1.4 The negative side Second signal value, the first threshold Th1 is set to about 1.2, and the second threshold Th2 is set to about -1.2.

[0025] The comparison / determination unit 143 compares the combined resolver signal generated by the combined signal generation unit 141 with the threshold value held in the threshold value holding unit 142, and determines the presence or absence of an abnormality in the two-phase resolver signals based on the comparison result. Specifically, first, the comparison unit 143a uses a window comparator or the like to compare the positive side waveform of the combined resolver signal with a first threshold value Th1 and compares the negative side waveform of the combined resolver signal with a second threshold value Th2. Based on the result of the comparison by the comparison unit 143a, the determination unit 143b determines whether or not there is an abnormality in the two-phase resolver signals. Second signal value is smaller than the first threshold Th1, and , the negative side of the composite resolver signal Second signal value is smaller than the second threshold value Th2, it is determined that the two-phase resolver signals include an abnormality, and an abnormality determination signal Err is output to the outside.

[0026] Fig. 5 shows a one-phase open circuit anomaly in which the first resolver signal is normal but the second resolver signal is abnormal due to a wire break. In this one-phase disconnection abnormality, the composite resolver signal is equal to the normal first resolver signal. Second signal value is smaller than the first threshold value Th1 and the negative side of the combined resolver signal Second signal value is smaller than the second threshold value Th2. Therefore, the determination unit 143b determines that the two-phase resolver signals include an abnormality based on the result of the comparison by the comparison unit 143a, and outputs an abnormality determination signal Err to the outside.

[0027] Figure 6 shows an anomaly in which a DC component is superimposed on at least one of the two-phase resolver signals, causing the waveform to shift to the positive or negative side. Here, the second resolver signal is normal, but a DC component is superimposed on the first resolver signal, causing an anomaly in which the waveform is shifted to the positive side (one-phase shift anomaly). With this one-phase shift anomaly, a DC component is also superimposed on the combined resolver signal in accordance with the shifted DC component of the first resolver signal, causing the waveform to shift to the positive side. As a result, the combined resolver signal has a DC component on the positive side. Second signal value is greater than the first threshold Th1 but is on the negative side Second signal value is smaller than the second threshold value Th2. Therefore, the determination unit 143b determines that the two-phase resolver signals include an abnormality based on the result of the comparison by the comparison unit 143a, and outputs an abnormality determination signal Err to the outside.

[0028] Although a specific example of a combination of a shift abnormality and a normal state is shown here, even if a shift abnormality and a wire break abnormality are combined, or if both phases are shift abnormal, when the determination unit 143b determines whether or not there is an abnormality in the two-phase resolver signals based on the result of the comparison by the comparison unit 143a, the positive side of the composite resolver signal is used. Second signal value is smaller than the first threshold Th1, and , the negative side of the composite resolver signal Second signal value is smaller than the second threshold value Th2. For this reason, the determination unit 143b determines that the two-phase resolver signals include an abnormality, and outputs an abnormality determination signal Err to the outside.

[0029] As described above, it is possible to realize a resolver signal abnormality detection circuit 140 and an angle detection device 100 capable of detecting an abnormality in a two-phase resolver signal using a circuit smaller than two systems of abnormality detection means for a two-phase resolver signal. In addition, the judgment unit 143b is capable of generating an abnormality judgment signal that distinguishes between the one-phase break abnormality shown in FIG. 5 and the one-phase shift abnormality shown in FIG. 6 based on the result of the comparison by the comparison unit 143a, and outputting the signal to the outside.

[0030] In the angle detection device 100, if one phase of the two-phase resolver signal is normal, the resolver / digital conversion circuit 110 can calculate the rotation angle θ of the resolver 10 and output the detected angle data φ. Therefore, when the angle detection device 100 is mounted on a vehicle and the angle detection device 100 outputs the detected angle data φ, if the resolver signal abnormality detection circuit 140 outputs an abnormality determination signal Err, the control unit of the vehicle can execute safety control such as stopping the vehicle in motion and preventing the vehicle from starting when stopped.

[0031] Embodiment 2 Abnormality detection in the resolver signal abnormality detection circuit 140 according to the second embodiment will be described below with reference to FIGS. 7 is a configuration diagram showing the configuration of an angle detection device 100 having a resolver signal abnormality detection circuit 140 according to a second embodiment. In FIG. 7, the same components as those in FIG. 1 are given the same numbers, and overlapping descriptions are omitted, and different portions are mainly described. Note that the resolver signal abnormality detection circuit 140 according to the second embodiment shown in FIG. 7 may be configured such that the angle detection device 100 and the resolver signal abnormality detection circuit 140 are separated as in FIG. 2. Fig. 8 is a waveform diagram showing the waveforms of two-phase resolver signals when only one phase is abnormal and a combined resolver signal waveform in the second embodiment. Fig. 9 is a waveform diagram showing the waveforms of two-phase resolver signals when both phases are abnormal and a combined resolver signal waveform in the second embodiment. In Figs. 8 and 9, the line types and indexes of each axis are the same as those in Figs. 3 to 6, and the explanation will focus on the differences. Note that in the following explanation, Signal ValueA small value means that the value is close to 0 regardless of whether it is positive or negative. Signal Value A large value means a value far from 0, regardless of whether it is positive or negative.

[0032] The threshold value holding unit 142 holds the first positive threshold value Th1 and the second negative threshold value Th2 described in the first embodiment, as well as the normal two-phase resolver signal. Maximum is Positive side No. 1 signal Value and Signal Value The third threshold Th3 between 0 and the positive side , and the same for the negative side. Negative fourth threshold Th4 of The threshold value storage unit 142 stores the Positive side No. 1 signal Values ​​of 1.0 and Negative first signal value When it is set to -1.0, the third threshold value should be set within the range of 0.3 to 0.7, and the fourth threshold value should be set within the range of -0.3 to -0.7.

[0033] FIG. 8 shows a state in which the first resolver signal is normal but the second resolver signal is abnormal due to a wire break, ie, a one-phase wire break abnormality. In this one-phase disconnection abnormality, the composite resolver signal is equal to the normal first resolver signal. Second signal value is smaller than the first threshold value Th1 and larger than the third threshold value Th3. Second signal value is smaller than the second threshold value Th2 and larger than the fourth threshold value Th4. Therefore, based on the result of the comparison by the comparison unit 143a, the determination unit 143b determines that only one phase of the two-phase resolver signal includes a wire break abnormality, and outputs an abnormality determination signal Err1 to the outside.

[0034] 9 shows a two-phase disconnection abnormality state in which both the first resolver signal and the second resolver signal are abnormal due to disconnection. In this two-phase disconnection abnormality, the combined resolver signal is equal to the abnormal first resolver signal and the abnormal second resolver signal. Signal Value 0. Therefore, the combined resolver signal is Second signal value is smaller than the third threshold Th3 and Second signal valueis smaller than the fourth threshold value Th4. Therefore, based on the result of the comparison by the comparison unit 143a, the determination unit 143b determines that both phases of the two-phase resolver signals are abnormal due to disconnection, and outputs an abnormality determination signal Err2 to the outside.

[0035] As described above, by using the third threshold value Th3 and the fourth threshold value Th4 in addition to the first threshold value Th1 and the second threshold value Th2, in addition to the effect obtained in the first embodiment, it becomes possible to distinguish and detect one-phase wire break anomalies and two-phase wire break anomalies in the two-phase resolver signal.

[0036] [Effects obtained by the embodiment] According to the first and second embodiments, the following effects can be obtained. The resolver signal abnormality detection circuit 140 according to the present invention is a circuit for detecting an abnormality in a two-phase resolver signal output from a resolver, and includes a composite signal generation unit 141 that generates a composite resolver signal by combining the two-phase resolver signals; Positive side No. 1 Threshold and the second negative threshold A threshold value holding unit 142 holds the composite resolver signal No. 1 Threshold and the second threshold and a comparison and determination unit 143 for comparing the two-phase resolver signals with each other and determining whether or not there is an abnormality based on the result of the comparison. Maximum positive value of Positive side No. 1 signal The normal combined resolver signal is calculated by dividing the normal combined resolver signal by the value of Maximum positive value of Positive side Second signal If the value is Positive side No. 1 signal Beyond Value Positive side Second signal Values ​​in the range up to No. 1 The comparison and determination unit 143 stores the combined resolver signal Maximum but The first and second thresholds If it is smaller than the threshold, it is determined to be abnormal. This makes it possible to realize the resolver signal abnormality detection circuit 140 capable of detecting an abnormality in a two-phase resolver signal using a circuit smaller in size than two-system abnormality detection means for a two-phase resolver signal.

[0037] The angle detection device 100 according to the present invention is a device for detecting the rotation angle of a resolver, and includes an excitation unit that generates a two-phase excitation signal and supplies the excitation signal to the resolver, a resolver / digital conversion circuit 110 that calculates the rotation angle of the resolver by processing the two-phase resolver signal output from the resolver, and the above-mentioned resolver signal abnormality detection circuit 140 that detects an abnormality in the two-phase resolver signal output from the resolver. This makes it possible to realize the angle detection device 100 capable of detecting an abnormality in a two-phase resolver signal using a circuit smaller than two-system abnormality detection means for a two-phase resolver signal.

[0038] In the resolver signal abnormality detection circuit 140 according to the present invention, the comparison and determination unit 143 compares the composite resolver signal No. 1 Threshold and the second threshold and a determination section 143b that determines whether or not there is an abnormality based on the result of the comparison in the comparison section 143a. This allows the judgment unit 143b to judge whether or not there is an abnormality in the two-phase resolver signal based on the result of the comparison by the comparison unit 143a, making it possible to detect an abnormality in the two-phase resolver signal using a circuit smaller than two-system abnormality detection means for the two-phase resolver signal.

[0039] In the resolver signal abnormality detection circuit 140 according to the present invention, the threshold holding unit 142 holds a first threshold on the positive side and a second threshold on the negative side as thresholds, and the comparison judgment unit 143 includes a window comparator and compares the composite resolver signal with the first threshold and the second threshold by the window comparator. This makes it possible to use a window comparator to compare the positive and negative waveforms of the composite resolver signal with a first positive threshold value and a second negative threshold value, making it possible to accurately detect abnormalities in the two-phase resolver signals using a circuit that is smaller in size than two systems of abnormality detection means for two-phase resolver signals.

[0040] In the resolver signal abnormality detection circuit 140 according to the present invention, the comparison and determination unit 143 detects the positive side of the combined resolver signal. Second signal value and a first threshold value, and the negative side of the combined resolver signal is Second signal value and a second threshold value, and the positive side of the combined resolver signal is Second signal value is smaller than the first threshold, and , the negative side of the composite resolver signal Second signal value is smaller than the first threshold value, it is determined that an abnormality has occurred. This allows both the positive and negative sides of the composite resolver signal to be Signal Value Not only when is smaller than the threshold, but also when either the positive or negative side of the composite resolver signal Signal Value It is also possible to determine that an abnormality exists even when the difference between the detected values ​​is smaller than the threshold value, making it possible to accurately detect an abnormality in a two-phase resolver signal using a circuit that is smaller in size than two systems of abnormality detection means for two-phase resolver signals.

[0041] In the resolver signal abnormality detection circuit 140 according to the present invention, the composite signal generation unit 141 generates a composite resolver signal by combining two-phase resolver signals by adding or subtracting them. This makes it possible to realize the resolver signal abnormality detection circuit 140 that can detect an abnormality in a two-phase resolver signal using a single circuit that is smaller in scale than two systems of abnormality detection means for two-phase resolver signals. [Explanation of symbols]

[0042] 10 resolver, 100 angle detection device, 110 resolver / digital conversion circuit, 120 reference signal generation unit, 130 excitation unit, 140 resolver signal abnormality detection circuit, 141 composite signal generation unit, 142 threshold value holding unit, 143 comparison judgment unit, 143a comparison unit, 143b judgment unit.

Claims

1. A resolver signal abnormality detection circuit (140) for detecting an abnormality in a two-phase resolver signal output from a resolver (10), comprising: a composite signal generating unit (141) that generates a composite resolver signal by combining the two-phase resolver signals; a threshold value storage unit (142) that stores a first threshold value on the positive side and a second threshold value on the negative side; a comparison and determination unit (143) that compares the composite resolver signal with the first threshold value and the second threshold value and determines the presence or absence of the abnormality based on a result of the comparison; Equipped with The threshold value storage unit (142) a maximum positive value of the two-phase resolver signals under normal conditions is defined as a first positive signal value, a maximum positive value of a normal-time combined resolver signal that is combined under normal conditions of the two-phase resolver signals is defined as a second positive signal value, and when the second positive signal value is greater than the first positive signal value, a value in a range from the first positive signal value to the second positive signal value is held as the first threshold value; a maximum negative value of the two-phase resolver signals under normal conditions is defined as a first negative signal value, a maximum negative value of a normal-time combined resolver signal that is combined under normal conditions of the two-phase resolver signals is defined as a second negative signal value, and when the absolute value of the second negative signal value is greater than the absolute value of the first negative signal value, a value in a range from the first negative signal value to the second negative signal value is held as a second threshold value; The comparison and determination unit (143) includes a window comparator, and uses the window comparator to compare the positive side second signal value of the combined resolver signal with the first threshold value, and compare the negative side second signal value of the combined resolver signal with the second threshold value, and determines that the abnormality exists when at least one of the following applies: the positive side second signal value of the combined resolver signal is smaller than the first threshold value, and the negative side second signal value of the combined resolver signal is smaller than the second threshold value. Resolver signal abnormality detection circuit.

2. The comparison and determination unit (143) a comparison unit (143a) for comparing the composite resolver signal with the first threshold value and the second threshold value; and a determination unit (143b) for determining the presence or absence of the abnormality based on a result of the comparison in the comparison unit (143a).

2. The resolver signal abnormality detection circuit according to claim 1.

3. The composite signal generating unit (141) generates the composite resolver signal by adding or subtracting the two-phase resolver signals.

2. The resolver signal abnormality detection circuit according to claim 1.

4. An angle detection device (100) for detecting a rotation angle of a resolver (10), an excitation unit (130) that generates a two-phase excitation signal and supplies the two-phase excitation signal to the resolver (10); A resolver / digital conversion circuit (110) that calculates a rotation angle of the resolver (10) by processing a two-phase resolver signal output from the resolver (10); A resolver signal abnormality detection circuit (140) according to any one of claims 1 to 3, which detects an abnormality in the two-phase resolver signals; An angle detection device having the following:

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