Rotary transformer signal anomaly detection circuit and angle detection device

Abstract

The invention provides a resolver signal abnormality detection circuit and an angle detection device which can detect abnormality of a two-phase resolver signal through a circuit smaller than a dual-system abnormality detection unit for the two-phase resolver signal. The resolver signal abnormality detection circuit includes: a combined signal generation unit that combines two-phase resolver signals to generate a combined resolver signal; a threshold value holding unit that holds a threshold value; and a comparison determination unit that compares the synthesized resolver signal with a threshold value, determines the presence or absence of an abnormality on the basis of the comparison result, and sets the amplitude of the two-phase resolver signal when the two-phase resolver signal is normal as a first amplitude value, when the amplitude of a normal-time synthesized resolver signal synthesized when the two-phase resolver signals are normal is set as a first amplitude value and the amplitude of a normal-time synthesized resolver signal synthesized when the two-phase resolver signals are normal is set as a second amplitude value, the threshold value holding unit holds a value within a range exceeding the first amplitude value and up to the second amplitude value as a threshold value, and the comparison determination unit determines that there is an abnormality when the amplitude of the synthesized resolver signal is less 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 novel improvement for detecting resolver signal abnormality in an angle detection device of a resolver using a two-phase excitation / two-phase output phase modulation method. Background Art

[0002] In an angle detection device of a resolver using a two-phase excitation / two-phase output phase modulation method, a scheme for detecting an abnormality of a resolver signal caused by a wire break in the resolver has been proposed. As a circuit for detecting such an abnormality of a resolver signal, for example, the configuration shown in Patent Document 1 can be cited.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-105047

[0006] exist Fig.10 The structure of such an angle detection device is shown in FIG. Fig.10 1 is a block diagram showing the structure of a conventional angle detection device 20. The angle detection device 20 detects the rotation angle of the phase modulation type resolver 10, and the angle detection device 20 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 is provided with a threshold holding unit 23a, a first comparison determination unit 23b, and a second comparison determination unit 23c.

[0007] Here, the first comparison determination unit 23b uses the threshold value from the threshold value holding unit 23a to detect the abnormality of the first resolver signal output from the resolver 10. The first comparison determination unit 23b outputs the first abnormality determination signal Err when the abnormality is detected. Similarly, the second comparison determination unit 23c uses the threshold value from the threshold value holding unit 23a to detect the abnormality of the second resolver signal output from the resolver 10. The second comparison determination unit 23c outputs the second abnormality determination signal Err when the abnormality is detected.

[0008] In this case, in order to detect abnormalities in the resolver signals of the two phases, the first comparison and determination unit 23b and the second comparison and determination unit 23c need to be provided as dual-system abnormality detection means, which increases the number of circuit elements and the circuit scale.

[0009] Therefore, it is desirable to realize an abnormality detection circuit capable of detecting an abnormality of two-phase resolver signals by a circuit smaller in scale than a dual-system abnormality detection unit for two-phase resolver signals, and an angle detection device having such an abnormality detection circuit. Summary of the invention

[0010] In order to solve the above problems, an object of the present invention is to provide a resolver signal abnormality detection circuit and an angle detection device that can detect abnormalities of two-phase resolver signals using a smaller-scale circuit than a dual-system abnormality detection unit for two-phase resolver signals.

[0011] The resolver signal abnormality detection circuit of the present invention is a resolver signal abnormality detection circuit for detecting the abnormality of two-phase resolver signals output from a resolver, and comprises: a synthetic signal generating unit for synthesizing the two-phase resolver signals to generate a synthetic resolver signal; a threshold holding unit for holding a threshold; and a comparison and determination unit for comparing the synthetic resolver signal with the threshold, and determining whether there is an abnormality based on the comparison result. When the amplitude of the two-phase resolver signals in normal state is set to a first amplitude value, and the amplitude of the synthetic resolver signal synthesized in the normal state of the two-phase resolver signals is set to a second amplitude value, the threshold holding unit holds a value within a range from the first amplitude value to the second amplitude value as the threshold, and the comparison and determination unit determines that the synthetic resolver signal is abnormal when the amplitude of the synthetic resolver signal is less than the threshold.

[0012] The angle detection device of the present invention is an angle detection device for detecting the rotation angle of a rotary transformer, and comprises: an excitation unit, which generates a two-phase excitation signal and supplies the excitation signal to the rotary transformer; a resolver / digital conversion circuit, which processes the two-phase resolver signals output from the rotary transformer to calculate the rotation angle of the rotary transformer; and a resolver signal abnormality detection circuit, which detects abnormalities in the two-phase resolver signals output from the rotary transformer.

[0013] In the resolver signal abnormality detection circuit of the present invention, the comparison and determination unit includes: a comparison unit that compares the synthesized resolver signal with a threshold value; and a determination unit that determines the presence or absence of abnormality based on a comparison result of the comparison unit.

[0014] 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 and determination unit has a window comparator, which compares the synthesized resolver signal with the first threshold and the second threshold through the window comparator.

[0015] In the resolver signal abnormality detection circuit of the present invention, the comparison and determination unit compares the amplitude of the positive side of the synthesized resolver signal with the first threshold value, and compares the amplitude of the negative side of the synthesized resolver signal with the second threshold value. When at least one of the amplitude of the positive side of the synthesized resolver signal is less than the first threshold value and the amplitude of the negative side of the synthesized resolver signal is less than the second threshold value, the comparison and determination unit determines that it is abnormal.

[0016] In the resolver signal abnormality detection circuit of the present invention, the synthesized signal generating unit generates a synthesized resolver signal by performing addition or subtraction on the two-phase resolver signals to synthesize them.

[0017] Effects of the Invention

[0018] According to the present invention, a resolver signal abnormality detection circuit and an angle detection device can be realized that can detect abnormality of two-phase resolver signals by using a smaller-scale circuit than a dual-system abnormality detection unit for two-phase resolver signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a diagram showing a configuration of an angle detection device including the resolver signal abnormality detection circuit according to the first embodiment.

[0020] Figure 2 This is a configuration diagram showing the configuration of the resolver signal abnormality detection circuit according to the first embodiment together with the angle detection device.

[0021] Figure 3 1 is a waveform diagram showing waveforms of two-phase resolver signals and a composite resolver signal in normal conditions in the first embodiment.

[0022] Figure 4 1 is a waveform diagram showing waveforms of two-phase resolver signals and a composite resolver signal in normal conditions in the first embodiment.

[0023] Figure 5 1 is a waveform diagram showing waveforms of resolver signals of two phases and a combined resolver signal in which only one phase is abnormal in the first embodiment.

[0024] Figure 6 1 is a waveform diagram showing waveforms of resolver signals of two phases and a combined resolver signal in which only one phase is abnormal in the first embodiment.

[0025] Figure 7 1 is a diagram showing a configuration of an angle detection device having a resolver signal abnormality detection circuit according to a second embodiment.

[0026] Figure 8 1 is a waveform diagram showing waveforms of resolver signals of two phases and a combined resolver signal in which only one phase is abnormal in the second embodiment.

[0027] Fig. 91 is a waveform diagram showing waveforms of resolver signals of two phases and a composite resolver signal when both phases are abnormal in the second embodiment.

[0028] Fig.10 This is a diagram showing the structure of a conventional resolver signal abnormality detection circuit.

[0029] Description of reference numerals:

[0030] 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: synthetic signal generation unit; 142: threshold holding unit; 143: comparison and determination unit; 143a: comparison unit; 143b: determination unit. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of a resolver signal abnormality detection circuit and an angle detection device according to the present invention will be described with reference to the drawings.

[0032] Implementation method 1.

[0033] First, refer to Figure 1 and Figure 2 , the resolver signal abnormality detection circuit and angle detection device in implementation mode 1 are described. Figure 1 1 is a diagram showing a configuration of an angle detection device 100 including a resolver signal abnormality detection circuit 140 according to the first embodiment. Figure 2 This is a configuration diagram showing the configuration of the resolver signal abnormality detection circuit 140 according to the first embodiment together with the angle detection device 100 .

[0034] [Configuration of the Angle Detection Device 100]

[0035] exist Figure 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 resolver.

[0036] exist Figure 2 In the embodiment, 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.

[0037] First, detection of the rotation angle θ of the resolver 10 by the angle detection device 100 will be described separately from signal generation and angle detection. Then, abnormality detection in the resolver signal abnormality detection circuit 140 will be described.

[0038] [Signal Generation]

[0039] The reference signal generating unit 120 generates a reference signal ωt indicating a time reference in accordance with a predetermined reference frequency ω. The reference signal generating unit 120 supplies the reference signal ωt to the resolver / digital converter circuit 110 and the excitation unit 130 .

[0040] 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 generating unit 120. The excitation unit 130 supplies the generated first excitation signal and the second excitation signal to the excitation winding of the rotary transformer 10. Hereinafter, the first excitation signal and the second excitation signal are referred to as "two-phase excitation signals".

[0041] [Angle detection]

[0042] When orthogonal two-phase excitation signals are supplied from the excitation unit 130, the two-phase excitation two-phase output and phase modulation type resolver 10 detects the magnetic flux generated by these excitation signals through the 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 is 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).

[0043] The resolver / digital conversion circuit 110 processes the two-phase resolver signals output from the resolver 10 using the reference signal ωt from the reference signal generating unit 120, thereby calculating the rotation angle θ of the resolver 10 and outputting the detection angle data φ corresponding to the rotation angle θ. It should be noted that the calculation of the rotation angle θ and the output of the detection angle data φ by the resolver / digital conversion circuit 110 are known contents, and therefore a detailed description thereof is omitted.

[0044] [Anomaly Detection]

[0045] The resolver signal abnormality detection circuit 140 includes a synthetic 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.

[0046] Here, refer to Figure 3 to Figure 6, the abnormality detection performed by the resolver signal abnormality detection circuit 140 is described. Figure 3 and Figure 4 1 is a waveform diagram showing waveforms of two-phase resolver signals and a composite resolver signal in normal conditions in the first embodiment. Figure 5 and Figure 6 1 is a waveform diagram showing waveforms of resolver signals of two phases and a combined resolver signal in which only one phase is abnormal in the first embodiment.

[0047] In these Figure 3 to Figure 6 In the figure, the horizontal axis represents the time t[s], the vertical axis represents the signal value obtained by normalizing the maximum amplitude of the two-phase resolver signals in normal conditions to 1.0, the first resolver signal is represented by a single-dotted line, the second resolver signal is represented by a double-dotted line, and the composite resolver signal is represented by a dotted line.

[0048] In the following description, a small amplitude of a waveform means a state close to 0 regardless of positive or negative, and a large amplitude of a waveform means a state far from 0 regardless of positive or negative.

[0049] The first resolver signal sin(ωt-θ) and the second resolver signal cos(ωt-θ) from the resolver 10 are supplied as two-phase resolver signals to the composite signal generator 141. The composite signal generator 141 generates a composite resolver signal by adding or subtracting the two-phase resolver signals. Figure 3 This shows a case where the normal two-phase resolver signals are added to generate a normal synthetic resolver signal √2sin(ωt-θ+45°).

[0050] Figure 4 It represents the situation where, in a normal two-phase resolver signal, the second resolver signal is subtracted from the first resolver signal to generate a normal synthetic resolver signal √2sin(ωt-θ+135°). It should be noted that, although not shown in the figure, in a normal two-phase resolver signal, when the first resolver signal is subtracted from the second resolver signal, a normal synthetic resolver signal √2sin(ωt-θ-45°) is obtained.

[0051] When the amplitude of the two-phase resolver signals in the normal state is set to the first amplitude value, and the amplitude of the normal synthesized resolver signal synthesized in the normal state of the two-phase resolver signals is set to the second amplitude value, the threshold holding unit 142 holds a value in the range from the first amplitude value to the second amplitude value as the threshold value. Specifically, the threshold holding unit 142 holds the first threshold value Th1 on the positive side and the second threshold value Th2 on the negative side as the above-mentioned threshold values.

[0052] exist Figure 3 and Figure 4In the example shown, when the normal amplitudes of the two-phase resolver signals, i.e., 1.0 and -1.0, are set as the first amplitude value, and the amplitudes of the normally synthesized resolver signals of the two-phase resolver signals, i.e., 1.4 and -1.4, are set as the second amplitude value, the first threshold value Th1 is set to approximately 1.2, and the second threshold value Th2 is set to approximately -1.2.

[0053] The comparison determination unit 143 compares the synthesized resolver signal generated by the synthesized signal generation unit 141 with the threshold value held by the threshold value holding unit 142 , and determines whether or not there is an abnormality in the resolver signals of the two phases based on the comparison result.

[0054] Specifically, first, the comparison unit 143 a compares the positive waveform of the synthesized resolver signal with the first threshold value Th1 , and compares the negative waveform of the synthesized resolver signal with the second threshold value Th2 using a window comparator or the like.

[0055] Moreover, based on the comparison result obtained by the comparison unit 143a, the determination unit 143b determines whether the resolver signals of the two phases are abnormal. When at least one of the amplitude of the positive side of the synthesized resolver signal is less than the first threshold value Th1 and the amplitude of the negative side of the synthesized resolver signal is less than the second threshold value Th2 is met, the determination unit 143b determines that the resolver signals of the two phases contain abnormalities, and outputs the abnormality determination signal Err to the outside.

[0056] exist Figure 5 It is shown in the figure that the first resolver signal is normal, but the second resolver signal is abnormal, which is caused by a broken wire and indicates a one-phase broken wire abnormality.

[0057] In the one-phase disconnection abnormality, the synthesized resolver signal is equal to the normal first resolver signal. Therefore, the positive amplitude of the synthesized resolver signal is smaller than the first threshold value Th1, and the negative amplitude of the synthesized resolver signal is smaller than the second threshold value Th2.

[0058] Therefore, the determination unit 143 b determines that the resolver signals of the two phases contain abnormality based on the comparison result obtained by the comparison unit 143 a , and outputs the abnormality determination signal Err to the outside.

[0059] exist Figure 6In the figure, the waveform is shifted to the positive side or the negative side due to the DC component being superimposed on at least one of the two-phase resolver signals. Here, the second resolver signal is normal, but the DC component is superimposed on the first resolver signal and the waveform is shifted to the positive side (one-phase shift abnormality). In this one-phase shift abnormality, according to the DC component of the offset first resolver signal, the DC component is also superimposed on the synthesized resolver signal, and the waveform is shifted to the positive side. Therefore, in the synthesized resolver signal, the amplitude on the positive side is greater than the first threshold value Th1, but the amplitude on the negative side is less than the second threshold value Th2. Therefore, the determination unit 143b determines that the resolver signals of the two phases contain an abnormality based on the comparison result obtained by the comparison unit 143a, and outputs the abnormality determination signal Err to the outside.

[0060] It should be noted that a specific example of the combination of offset abnormality and normality is shown here, but even if it is a combination of offset abnormality and disconnection abnormality or a combination of both phases with offset abnormality, when the determination unit 143b determines whether the resolver signals of the two phases are abnormal based on the comparison result obtained by the comparison unit 143a, it also meets at least one of the amplitude of the positive side of the synthesized resolver signal being less than the first threshold value Th1 and the amplitude of the negative side of the synthesized resolver signal being less than the second threshold value Th2. Therefore, the determination unit 143b determines that the resolver signals of the two phases contain abnormality, and outputs the abnormality determination signal Err to the outside.

[0061] As described above, the resolver signal abnormality detection circuit 140 and the angle detection device 100 capable of detecting abnormalities in two-phase resolver signals can be realized by using a smaller-scale circuit than the dual-system abnormality detection unit for two-phase resolver signals.

[0062] In addition, the determination unit 143b can generate a classification based on the comparison result obtained by the comparison unit 143a. Figure 5 The one-phase disconnection abnormality and Figure 6 The abnormality determination signal of one phase deviation abnormality shown is output to the outside.

[0063] In the angle detection device 100, as long as one of the two-phase resolver signals is normal, the resolver / digital conversion circuit 110 can calculate the rotation angle θ of the resolver 10 and output the detection angle data φ. Therefore, when the angle detection device 100 is mounted on a vehicle and the detection angle data φ is output from the angle detection device 100, when the resolver signal abnormality detection circuit 140 outputs the abnormality determination signal Err, the control unit of the vehicle can perform safety control such as stopping the running vehicle and suppressing the start of the stopped vehicle.

[0064] Implementation method 2.

[0065] Below, refer to Figure 7 to Figure 9, abnormality detection of the resolver signal abnormality detection circuit 140 according to the second embodiment is described.

[0066] Figure 7 2 is a block diagram showing the configuration of an angle detection device 100 having a resolver signal abnormality detection circuit 140 according to Embodiment 2. Figure 7 In, with Figure 1 The same components are marked with the same reference numerals, and repeated descriptions are omitted, and the description will be centered on the different parts. Figure 7 The resolver signal abnormality detection circuit 140 of the second embodiment shown in FIG. Figure 2 In this way, the angle detection device 100 and the resolver signal abnormality detection circuit 140 are separated.

[0067] Figure 8 1 is a waveform diagram showing waveforms of resolver signals of two phases and a combined resolver signal in which only one phase is abnormal in the second embodiment. Fig. 9 : is a waveform diagram showing the waveforms of the resolver signals of two phases and the synthesized resolver signal in Embodiment 2, both phases being abnormal. Figure 8 and Fig. 9 In the Figure 3 to Figure 6 It should be noted that in the following description, a small amplitude of a waveform means a state close to 0 regardless of positive or negative, and a large amplitude of a waveform means a state far from 0 regardless of positive or negative.

[0068] In addition to the first threshold Th1 on the positive side and the second threshold Th2 on the negative side described in Embodiment 1, the threshold holding unit 142 also holds the third threshold Th3 on the positive side and the fourth threshold Th4 on the negative side between the first amplitude value, which is the amplitude of the two-phase resolver signal in the normal state, and the amplitude 0. It should be noted that when the first amplitude value is set to 1.0 and -1.0, the threshold holding unit 142 sets the third threshold value in the range of 0.3 to 0.7 and sets the fourth threshold value in the range of -0.3 to -0.7.

[0069] exist Figure 8 , a state in which the first resolver signal is normal but the second resolver signal is abnormal due to a one-phase broken wire abnormality is shown.

[0070] In the one-phase broken line abnormality, the synthesized resolver signal is equal to the normal first resolver signal. Therefore, the amplitude of the positive side of the synthesized resolver signal is less than the first threshold value Th1 and greater than the third threshold value Th3. The amplitude of the negative side of the synthesized resolver signal is less than the second threshold value Th2 and greater than the fourth threshold value Th4. Therefore, the determination unit 143b determines that only one phase of the two-phase resolver signals contains a broken line abnormality based on the comparison result obtained by the comparison unit 143a, and outputs the abnormality determination signal Err1 to the outside.

[0071] exist Fig. 9 , a state of a two-phase broken wire abnormality in which both the first resolver signal and the second resolver signal are abnormal due to broken wire is shown. In this two-phase broken wire abnormality, the synthesized resolver signal is equal to the abnormal first resolver signal and the abnormal second resolver signal, and becomes an amplitude of 0. Therefore, the amplitude of the positive side of the synthesized resolver signal is less than the third threshold value Th3, and the amplitude of the negative side of the synthesized resolver signal is less than the fourth threshold value Th4. Therefore, based on the comparison result obtained by the comparison unit 143a, the determination unit 143b determines that both phases of the resolver signals of the two phases are broken wire abnormalities, and outputs the abnormal determination signal Err2 to the outside.

[0072] As described above, in addition to the first threshold Th1 and the second threshold Th2, the third threshold Th3 and the fourth threshold Th4 are also used. In addition to the effect obtained by the first embodiment, it is also possible to distinguish between single-phase disconnection abnormality and two-phase disconnection abnormality for abnormalities of the resolver signals of the two phases.

[0073] [Effects obtained by the embodiment]

[0074] According to the first and second embodiments, the following effects can be obtained.

[0075] The resolver signal abnormality detection circuit 140 of the present invention is a circuit for detecting the abnormality of the two-phase resolver signals output from the resolver, and comprises: a synthetic signal generating unit 141, which synthesizes the two-phase resolver signals to generate a synthetic resolver signal; a threshold holding unit 142, which holds the threshold; and a comparison and determination unit 143, which compares the synthetic resolver signal with the threshold, and determines whether there is an abnormality based on the comparison result. When the amplitude of the two-phase resolver signals in normal state is set to a first amplitude value, and the amplitude of the synthetic resolver signal synthesized in the normal state of the two-phase resolver signals is set to a second amplitude value, the threshold holding unit 142 holds a value within a range from the first amplitude value to the second amplitude value as the threshold, and the comparison and determination unit 143 determines that there is an abnormality when the amplitude of the synthetic resolver signal is less than the threshold.

[0076] Thus, the resolver signal abnormality detection circuit 140 capable of detecting abnormality of two-phase resolver signals can be realized with a smaller-scale circuit than the dual-system abnormality detection unit for two-phase resolver signals.

[0077] The angle detection device 100 of the present invention is a device for detecting the rotation angle of a rotary transformer, and comprises: an excitation unit, which generates a two-phase excitation signal and supplies the excitation signal to the rotary transformer; a resolver / digital conversion circuit 110, which processes the two-phase resolver signals output from the rotary transformer to calculate the rotation angle of the rotary transformer; and the above-mentioned resolver signal abnormality detection circuit 140, which detects the abnormality of the two-phase resolver signals output from the rotary transformer.

[0078] Thus, the angle detection device 100 capable of detecting an abnormality in two-phase resolver signals can be realized by using a smaller-scale circuit than a dual-system abnormality detection unit for two-phase resolver signals.

[0079] In the resolver signal abnormality detection circuit 140 of the present invention, the comparison and determination unit 143 includes: a comparison unit 143a for comparing the synthesized resolver signal with a threshold value; and a determination unit 143b for determining the presence or absence of abnormality based on the comparison result in the comparison unit 143a.

[0080] Therefore, the determination unit 143b can determine whether there is any abnormality in the two-phase resolver signals based on the comparison result obtained by the comparison unit 143a, and can detect the abnormality of the two-phase resolver signals through a smaller circuit than the dual-system abnormality detection unit used for the two-phase resolver signals.

[0081] In the resolver signal abnormality detection circuit 140 of the present invention, the threshold holding unit 142 maintains the first threshold on the positive side and the second threshold on the negative side as thresholds, and the comparison and determination unit 143 has a window comparator, which compares the synthesized resolver signal with the first threshold and the second threshold through the window comparator.

[0082] Thus, a window comparator can be used to compare the positive and negative waveforms of the synthesized resolver signal with the positive first threshold and the negative second threshold, and the anomalies of the two-phase resolver signal can be accurately detected by a smaller-scale circuit than the dual-system anomaly detection unit used for the two-phase resolver signal.

[0083] In the resolver signal abnormality detection circuit 140 of the present invention, the comparison and determination unit 143 compares the amplitude of the positive side of the synthesized resolver signal with the first threshold, and compares the amplitude of the negative side of the synthesized resolver signal with the second threshold. When at least one of the amplitude of the positive side of the synthesized resolver signal is less than the first threshold and the amplitude of the negative side of the synthesized resolver signal is less than the second threshold, the comparison and determination unit 143 determines that it is abnormal.

[0084] Therefore, not only can it be determined as an abnormality when the amplitude of both the positive side and the negative side of the synthesized resolver signal is smaller than the threshold, but it can also be determined as an abnormality when the amplitude of one of the positive side and the negative side of the synthesized resolver signal is smaller than the threshold. The abnormality of the two-phase resolver signal can be accurately detected by a smaller-scale circuit than the dual-system abnormality detection unit for the two-phase resolver signal.

[0085] In the resolver signal abnormality detection circuit 140 of the present invention, the synthetic signal generation unit 141 generates a synthetic resolver signal by performing addition or subtraction operations on the resolver signals of the two phases. Thus, the resolver signal abnormality detection circuit 140 capable of detecting abnormalities of the resolver signals of the two phases can be realized by a circuit of a single system smaller in scale than the dual-system abnormality detection unit for the resolver signals of the two phases.

Claims

1. A resolver signal abnormality detection circuit, which is a resolver signal abnormality detection circuit (140) for detecting abnormalities of two-phase resolver signals output from a resolver (10), characterized in that: have: A synthetic signal generating unit (141) synthesizes the resolver signals of the two phases to generate a synthetic resolver signal; A threshold holding unit (142) that holds a threshold; and A comparison and determination unit (143) compares the synthesized resolver signal with the threshold value and determines whether the abnormality exists based on the comparison result. When the amplitude of the two-phase resolver signals in a normal state is set to a first amplitude value, and the amplitude of the normal synthesized resolver signal synthesized in a normal state of the two-phase resolver signals is set to a second amplitude value, the threshold holding unit (142) holds a value within a range exceeding the first amplitude value and up to the second amplitude value as the threshold value, The comparison and determination unit (143) determines that the abnormality occurs when the amplitude of the synthesized resolver signal is smaller than the threshold value.

2. The resolver signal abnormality detection circuit according to claim 1, characterized in that: The comparison and determination unit (143) comprises: A comparing unit (143a) for comparing the synthesized resolver signal with the threshold value; and The determination unit (143b) determines whether the abnormality exists based on the comparison result of the comparison unit (143a).

3. The resolver signal abnormality detection circuit according to claim 1, characterized in that: The threshold value holding unit (142) holds a first threshold value on the positive side and a second threshold value on the negative side as the threshold value, The comparison and determination unit (143) includes a window comparator, and compares the synthesized resolver signal with the first threshold value and the second threshold value through the window comparator.

4. The resolver signal abnormality detection circuit according to claim 3, characterized in that: The comparison and determination unit (143) compares the amplitude of the positive side of the synthesized resolver signal with the first threshold value, and compares the amplitude of the negative side of the synthesized resolver signal with the second threshold value, The comparison and determination unit (143) determines that the abnormality occurs when at least one of the amplitude of the positive side of the synthesized resolver signal is smaller than the first threshold and the amplitude of the negative side of the synthesized resolver signal is smaller than the second threshold.

5. The resolver signal abnormality detection circuit according to claim 1, characterized in that: The synthesized signal generating unit (141) generates the synthesized resolver signal by performing addition or subtraction on the resolver signals of the two phases to synthesize them.

6. An angle detection device, which is an angle detection device (100) for detecting the rotation angle of a rotary transformer (10), characterized in that: have: An excitation unit (130) generates two-phase excitation signals and supplies the two-phase excitation signals to the rotary transformer (10); A resolver / digital conversion circuit (110) processes two-phase resolver signals output from the resolver (10), thereby calculating the rotation angle of the resolver (10); and The resolver signal abnormality detection circuit (140) according to any one of claims 1 to 5 detects abnormalities in the resolver signals of the two phases.

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