Angle detection method and angle detection device

Abstract

To determine abnormality of a resolver / digital conversion part in an angle detection device using a phase modulation type resolver, without complicating a circuit configuration and handling of a signal line.SOLUTION: An angle detection device for detecting a rotation angle θ of a phase modulation type resolver 10 includes: a reference signal generation part 120 for generating a reference signal; a resolver / digital conversion part 110 for processing a resolver signal output from the resolver 10, thereby generating a detection angle φ according to a rotation angle θ of the resolver 10, and generating phase output having a shift of a phase corresponding to the rotation angle θ with respect to the reference signal; an excitation part 130 for generating a two-phase excitation signal according to the phase output, and supplying the excitation signal to an excitation winding of the resolver 10; and an abnormality monitoring part 140 for comparing the phase of the reference signal with the phase of the resolver signal, and determining that the resolver / digital conversion part 110 is abnormal when a phase difference exceeds a threshold.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an angle detection method and an angle detection device, and particularly to a novel improvement for determining an abnormality in a resolver / digital conversion unit in an angle detection device using a resolver of a two-phase excitation / two-phase output or two-phase excitation / one-phase output and a phase modulation method.

Background Art

[0002] In an angle detection device using a resolver, it has been proposed to perform an abnormality determination of a resolver / digital conversion unit. Examples of this type of angle detection method and angle detection device include the configuration shown in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the angle detection device described in Patent Document 1 above, while obtaining angle information based on a resolver signal in the resolver / digital conversion unit, angle information is also obtained based on the resolver signal in the control CPU. The control CPU compares the angle information obtained by the resolver / digital conversion unit with the angle information obtained by itself, and if they match, determines that the angle detection device is normal.

[0005] In the case of the angle detection device described in Patent Document 1, since an analog resolver signal is input to the control CPU, it is necessary to newly provide an interface such as an A / D conversion unit, which complicates the circuit configuration and signal wiring.

[0006] Therefore, there was a need to determine abnormalities in the resolver / digital conversion section of an angle detection device using a phase-modulation resolver without complicating the circuit configuration or signal line routing. To solve the above-mentioned problems, the present invention aims to provide an angle detection method and an angle detection device that can determine abnormalities in the resolver / digital conversion section of an angle detection device using a phase-modulation resolver without complicating the circuit configuration and signal line routing. [Means for solving the problem]

[0007] The angle detection method according to this invention is an angle detection method for detecting the rotation angle of a phase-modulated resolver, and comprises: a function of generating a phase output having a phase shift corresponding to the rotation angle of the resolver with respect to a reference signal generated by a reference signal generation unit using a resolver / digital conversion unit; a function of generating a two-phase excitation signal corresponding to the phase output using an excitation unit and supplying the excitation signal to the excitation winding of the resolver; a function of processing the resolver signal output from the resolver in the resolver / digital conversion unit to generate a detection angle corresponding to the rotation angle of the resolver; and a function of comparing the phase of the reference signal and the phase of the resolver signal using an abnormality monitoring unit, and determining that the resolver / digital conversion unit is abnormal if the phase difference exceeds a threshold.

[0008] The angle detection device according to this invention is an angle detection device for detecting the rotation angle of a phase-modulated resolver, and comprises: a reference signal generation unit that generates a reference signal; a resolver / digital conversion unit that processes a resolver signal output from the resolver to generate a detection angle φ corresponding to the rotation angle of the resolver and generates a phase output having a phase shift corresponding to the rotation angle with respect to the reference signal; an excitation unit that generates a two-phase excitation signal corresponding to the phase output and supplies the excitation signal to the excitation winding of the resolver; and an abnormality monitoring unit that compares the phase of the reference signal with the phase of the resolver signal and determines that the resolver / digital conversion unit is abnormal if the phase difference exceeds a threshold.

[0009] This invention is characterized in that a first-phase resolver signal and a second-phase resolver signal are output from the resolver, the phase of the reference signal and the first-phase resolver signal are compared by an abnormality monitoring unit, and the phase of the second-phase reference signal, which is shifted in phase by +90° with respect to the reference signal, and the second-phase resolver signal are compared by an abnormality monitoring unit.

[0010] In this invention, the digital data of a reference signal is generated by a reference signal generation unit, the resolver signal is converted into binary data by a comparator, the exclusive OR operation circuit calculates the exclusive OR of the inverted phase data obtained from the most significant bit or the upper two bits of the digital data constituting the reference signal and the binary data, and if the period of mismatch between the two inputs of the exclusive OR operation circuit is greater than a threshold, the determination unit determines that it is abnormal and generates an abnormal determination signal. [Effects of the Invention]

[0011] According to this invention, it is possible to determine abnormalities in the resolver / digital conversion section of an angle detection device using a phase-modulation resolver without complicating the circuit configuration or signal line routing. [Brief explanation of the drawing]

[0012] [Figure 1] This is a configuration diagram showing the configuration of the angle detection device according to Embodiment 1. [Figure 2] This is a configuration diagram showing the configuration of the angle detection device according to Embodiment 2. [Figure 3] This is a configuration diagram showing the main components of the angle detection device according to Embodiment 2. [Modes for carrying out the invention]

[0013] The following describes embodiments of the angle detection method and angle detection device of the present invention with reference to the drawings.

[0014] Embodiment 1. First, the basic configuration and processing of the angle detection device 100 in Embodiment 1 will be described with reference to FIG. 1. FIG. 1 is a configuration diagram showing the configuration of the angle detection device 100 according to Embodiment 1. Note that the angle detection device 100 is also a device that executes each processing function of the angle detection method.

[0015] [Configuration of Angle Detection Device 100 and Processing of Each Part] In FIG. 1, the angle detection device 100 that executes the angle detection method mainly includes a resolver / digital conversion unit 110, a reference signal generation unit 120, an excitation unit 130, and an abnormality monitoring unit 140. In FIG. 1, a resolver 10 with two-phase excitation / two-phase output is connected to the angle detection device 100 as a resolver of the phase modulation method.

[0016] First, generation of the detection angle φ corresponding to the rotation angle θ of the resolver 10 in the resolver 10, the resolver / digital conversion unit 110, the reference signal generation unit 120, and the excitation unit 130 will be described separately for signal generation and angle detection. Then, abnormality monitoring in the abnormality monitoring unit 140 will be described.

[0017] [Signal Generation] The reference signal generation unit 120 generates a reference signal ω R t representing the time reference corresponding to a predetermined reference frequency ω R t, a reference sine signal sinω R t representing the sine of the reference signal ω R t, and a reference cosine signal cosω R t representing the cosine of the reference signal ω R t. The reference signal generation unit 120 supplies the reference signal ω R t to the resolver / digital conversion unit 110 and the abnormality monitoring unit 140, and supplies the reference sine signal sinω R t and the reference cosine signal cosω R t to the resolver / digital conversion unit 110.

[0018] The resolver / digital conversion unit 110 is the reference signal ω generated by the reference signal generation unit 120 RFor t, the phase output ω has a detection angle φ corresponding to the rotation angle θ of the resolver 10. R Generate t+φ and the generated phase output ω R t+φ is supplied to the excitation unit 130. The resolver / digital conversion unit 110 will be explained in detail later.

[0019] The excitation unit 130 receives the phase output ω supplied from the resolver / digital conversion unit 110. R Based on t+φ, the excitation signal of the first phase is sin(ω) as an orthogonal two-phase excitation signal. R t + φ) and the excitation signal of the second phase cos(ω R The excitation unit 130 generates the excitation signal sin(ω) of the first phase that was generated. R t+φ) and the excitation signal of the second phase cos(ω R The voltage (t + φ) is supplied to the excitation winding of resolver 10. As described above, the excitation unit 130 receives the reference signal ω R An excitation signal is generated based on t and the detected angle φ.

[0020] [Angle detection] The resolver 10, which is a two-phase excitation two-phase output and phase modulation type, receives two orthogonal excitation signals (first phase excitation signal sin(ω)) from the excitation unit 130. R t + φ) and the excitation signal of the second phase cos(ω R When t+φ)) is supplied, the magnetic flux generated by these excitation signals is detected by the detection winding, and a two-phase phase-modulated analog signal with a phase corresponding to the rotation angle θ is output as a two-phase resolver signal. The two-phase resolver signal has a phase corresponding to the rotation angle θ, and the first phase resolver signal sin(ω R t + φ - θ) and the resolver signal of the second phase cos(ω R It can be expressed as t + φ - θ).

[0021] The resolver / digital conversion unit 110 includes a first multiplier 111a, a second multiplier 111b, a subtractor 112, an A / D conversion unit 113, a control rule 114, an accumulator 115, and an adder 116. The first multiplier 111a processes the resolver signal sin(ω) of the first phase. R t+φ-θ) and the reference cosine signal cosω R Multiply by t and get the first intermediate signal sin(ω R t + φ - θ)·cosω R The first multiplier 111a generates t. R t + φ - θ)·cosω R t is supplied to one input of the subtractor 112. The second multiplier 111b outputs the second phase resolver signal cos(ω R t+φ-θ) and the reference sine signal sinω R Multiply by t and get the second intermediate signal cos(ω R t + φ - θ)·sinω R The second multiplier 111b generates t. R t + φ - θ)·sinω R t is supplied to the other input of the subtractor 112. The subtractor 112 outputs the first intermediate signal sin(ω R t + φ - θ)·cosω R t and the second intermediate signal cos(ω R t + φ - θ)·sinω R The difference ε with t is calculated. In negative feedback control, the angle detection device 100 uses the difference ε as the control deviation and determines the value of the detected angle φ so that this control deviation becomes 0 or approaches 0. The subtractor 112 supplies the difference ε to the A / D conversion unit 113.

[0022] The A / D conversion unit 113 digitizes the difference ε and generates a digitized difference Dε. The A / D conversion unit 113 supplies the generated digitized difference Dε to the control law 114. The control rule 114 is applied to the digitized difference Dε to generate an angular velocity signal ω as a control signal. The control rule 114 supplies the generated angular velocity signal ω to the accumulator 115. The control rule 114 has integral characteristics and is designed to improve the characteristics of the negative feedback system and ensure stability.

[0023] The accumulator 115 performs cumulative calculations, accumulating the input angular velocity signal ω to generate a detected angle φ representing the rotation angle θ. The detected angle φ generated by the accumulator 115 is supplied externally from the angle detection device 100 as the result of the rotation angle θ detection by the resolver 10, and is also supplied to the adder 116. The adder 116 takes the detection angle φ and the reference signal ω from the reference signal generation unit 120. R Phase output ω, which corresponds to the sum with t. R It generates t+φ. The adder 116 outputs the generated phase output ω R t+φ is supplied to the excitation unit 130 as the basis for the excitation signal.

[0024] As described above, the resolver / digital conversion unit 110 processes the resolver signal from the resolver 10 and generates a detection angle φ corresponding to the rotation angle θ of the resolver 10.

[0025] [Abnormality monitoring] The abnormality monitoring unit 140 includes a phase shift unit 141, inversion units 142a and 142b, a first comparator 143a, a second comparator 143b, a first exclusive OR operation circuit 144a, a second exclusive OR operation circuit 144b, a first determination unit 145a, a second determination unit 145b, and an OR operation circuit 146. Furthermore, the first exclusive OR operation circuit 144a and the second exclusive OR operation circuit 144b may be configured to perform a negated exclusive OR operation XNOR instead of an exclusive OR operation XOR by inverting the logic thereafter.

[0026] One input to the first exclusive OR operation circuit 144a is the reference signal ω from the reference signal generation unit 120. R Inverted data, inverted by the inversion unit 142a, is supplied. One input to the second exclusive OR circuit 144b is the second phase reference signal ω, which has been phase-shifted by +90° by the phase shift unit 141 to match the phase of the second phase resolver signal. R Inverted data is supplied, with t+90° inverted by the inversion unit 142b. Phase adjustment in the phase shift unit 141 is performed, for example, by the reference signal ωR This is performed by adjusting the upper two bits of the digital data that makes up t.

[0027] The first comparator 143a processes the resolver signal sin(ω) of the first phase. R The first phase resolver signal binary data DR1 is generated by binarizing t+φ-θ). The first comparator 143a supplies the generated first phase resolver signal binary data DR1 to the other input of the first exclusive OR operation circuit 144a. The second comparator 143b controls the resolver signal of the second phase cos(ω R The second phase resolver signal binary data DR2 is generated by binarizing t+φ-θ). The second comparator 143b supplies the generated first phase resolver signal binary data DR2 to the other input of the second exclusive OR operation circuit 144b.

[0028] Here, the anomaly monitoring unit 140 compares the phase of the reference signal with the phase of the resolver signal. The first exclusive OR circuit 144a uses a reference signal ω as one of its inputs. R The phase comparison is performed by performing an exclusive OR operation between the inverted data of the most significant bit of the digital data constituting t and the other input, the first-phase resolver signal binary data DR1. An L level is output during the period when the two inputs match, and an H level is output during the period when the two inputs do not match. Note that the "inverted data of the most significant bit" mentioned above may also be the inverted data of the phase data obtained from the upper two bits. Hereafter, "inverted data of the phase data obtained from the most significant bit or the upper two bits" will simply be referred to as "inverted data of the most significant bit". The second exclusive OR circuit 144b uses the reference signal ω as one of its inputs. R The most significant bit of the digital data constituting t+90° is inverted, and the other input, the second-phase resolver signal binary data DR2, is compared using an exclusive OR operation. A low level is output when the two inputs match, and a high level is output when the two inputs do not match.

[0029] Next, the abnormality monitoring unit 140 checks whether the period of mismatch between the phase of the reference signal and the phase of the resolver signal exceeds a threshold. Subsequently, if the period of mismatch between the phase of the reference signal and the phase of the resolver signal exceeds the threshold, the abnormality monitoring unit 140 determines that the resolver / digital conversion unit 110 is malfunctioning. The first determination unit 145a outputs an L level signal indicating normal operation if the mismatch period between the two inputs of the first exclusive OR operation circuit 144a is less than or equal to a threshold, and generates an H level abnormality determination signal if the mismatch period is greater than the threshold. The first determination unit 145a supplies either an L level or an H level output to one input of the OR operation circuit 146. The second determination unit 145b outputs an L level signal indicating normal operation if the mismatch period between the two inputs of the second exclusive OR operation circuit 144b is less than or equal to a threshold, and generates an H level abnormality determination signal if the mismatch period is greater than the threshold. The second determination unit 145b supplies the L level or H level output to the other input of the OR operation circuit 146.

[0030] Subsequently, the abnormality monitoring unit 140 notifies a predetermined recipient of the determination result that an abnormality has occurred. Specifically, the logical OR operation circuit 146 performs a logical OR operation between the output of the first determination unit 145a and the output of the second determination unit 145b. If an abnormality determination signal of H level is output from either the first determination unit 145a or the second determination unit 145b, it outputs an abnormality determination signal Err to a predetermined recipient. The predetermined recipient may be a higher-level control device or display unit.

[0031] [Explanation of the principle of anomaly monitoring] The resolver signal output from resolver 10 is phase-modulated with respect to the excitation signal and output. The excitation unit 130 uses a reference signal ω R Phase output ω has a phase shifted by the detection angle φ relative to t. R The excitation signal is generated based on t+φ. Therefore, if the resolver / digital conversion unit 110 is in a healthy state, i.e., normal, the rotation angle θ of the resolver 10 and the detection angle φ generated and output by the resolver / digital conversion unit 110 will match. As a result, the phase of the resolver signal will match the phase of the reference signal.

[0032] Here, the reference signal ω R Using t, the rotation angle θ of the resolver 10, and the detection angle φ generated by the resolver / digital conversion unit 110, the phase of the excitation signal and the phase of the resolver signal are as follows. Phase of the excitation signal: ω R t+φ Phase of resolver signal: ω R t + φ - θ When comparing the phase of the resolver signal, which has the above relationship, with the phase of the reference signal, if the resolver / digital conversion unit 110 is operating normally, φ = θ, and the phase of the resolver signal becomes the same as the phase of the reference signal.

[0033] On the other hand, if the resolver / digital conversion unit 110 is malfunctioning, the resolver / digital conversion unit 110 will no longer be able to obtain a detection angle φ that matches the rotation angle θ of the resolver 10. As a result, a phase difference will occur between the resolver signal and the reference signal. Therefore, the malfunction monitoring unit 140 detects the above phase difference and determines that the resolver / digital conversion unit 110 is in a malfunctioning state if the phase shift exceeds a preset threshold. This allows the system to detect whether the resolver / digital conversion unit 110 is normal or abnormal and monitor its health. The anomaly monitoring unit 140 uses logic circuits as its main component, and compared to prior art using a control CPU, it is possible to significantly simplify the circuit configuration and signal line routing, and the accuracy of the judgment is also improved. The above thresholds can be set to any value according to the requirements of the device to which the resolver 10 is installed.

[0034] Embodiment 2. Next, the basic configuration of the angle detection device 100 in Embodiment 2 will be described with reference to Figures 2 and 3. Figure 2 is a configuration diagram showing the configuration of the angle detection device 100 in Embodiment 2. Figure 3 is a configuration diagram showing the configuration of the main part of the angle detection device 100 in Embodiment 2.

[0035] [Configuration of the angle detection device 100 and processing of each part] In Figure 2, identical items to those in Figure 1 are given the same numbers to avoid redundant explanations and focus the explanation on the differences. In Figure 2, the angle detection device 100 mainly comprises a resolver / digital conversion unit 110, a reference signal generation unit 120, an excitation unit 130, and an abnormality monitoring unit 140. In Figure 2, a two-phase excitation / one-phase output resolver 10 is connected to the angle detection device 100 as a phase-modulation type resolver.

[0036] [Signal generation] The reference signal generation unit 120 generates a predetermined reference frequency ω R The reference signal ω corresponds to the time reference. R t and the reference signal ω R The reference cosine signal cosω represents the cosine of t. R The reference signal generation unit 120 generates the reference signal ω. R t is supplied to the resolver / digital conversion unit 110 and the anomaly monitoring unit 140, and the generated reference cosine signal cosω R t is supplied to the resolver / digital conversion unit 110. The excitation unit 130 receives the phase output ω supplied from the resolver / digital conversion unit 110. R Based on t+φ, the excitation signal of the first phase is sin(ω) as an orthogonal two-phase excitation signal. R t + φ) and the excitation signal of the second phase cos(ω R It generates (t + φ) and supplies it to the excitation winding of resolver 10.

[0037] [Angle detection] The resolver 10, which is a two-phase excitation, one-phase output, and phase-modulated resolver, receives two orthogonal excitation signals (first phase excitation signal sin(ω)) from the excitation unit 130. Rt + φ) and the excitation signal of the second phase cos(ω R When t+φ)) is supplied, the magnetic flux generated by these excitation signals is detected by the detection winding, and a one-phase phase-modulated analog signal with a phase corresponding to the rotation angle θ is output as a one-phase resolver signal. The one-phase resolver signal has a phase corresponding to the rotation angle θ, and sin(ω R It can be expressed as t + φ - θ).

[0038] The resolver / digital conversion unit 110 has a phase output ω, similar to Embodiment 1. R The output t+φ is directed towards the excitation unit 130, and the resolver signal from the resolver 10 is processed to generate a detection angle φ corresponding to the rotation angle θ of the resolver 10.

[0039] [Abnormality monitoring] The abnormality monitoring unit 140 includes an inversion unit 142, a comparator 143, an exclusive OR operation circuit 144, and a determination unit 145. The exclusive OR operation circuit 144 may be configured to perform a negative exclusive OR operation (XNOR) instead of an exclusive OR operation (XOR) by inverting the logic of the determination unit 145.

[0040] One input to the exclusive OR operation circuit 144 is the reference signal ω from the reference signal generation unit 120. R Inverted data, in which t is inverted by the inversion unit 142, is supplied. Comparator 143 outputs the resolver signal sin(ω R The binary data DR of the resolver signal is generated by binarizing t+φ-θ. The comparator 143 supplies the generated binary data DR of the resolver signal to the other input of the exclusive OR operation circuit 144.

[0041] The exclusive OR operation circuit 144 uses the reference signal ω as one of its inputs. R The phase comparison is performed by performing an exclusive OR operation between the inverted data of the most significant bit of the digital data constituting t and the binary data of the resolver signal DR, which is the other input. An L level is output when the two inputs match, and an H level is output when the two inputs do not match.

[0042] The determination unit 145 outputs an L level signal indicating normal operation if the mismatch period between the two inputs of the exclusive OR operation circuit 144 is less than or equal to a threshold, and generates an H level abnormality determination signal if the mismatch period is greater than the threshold. When the abnormality monitoring unit 140 receives an H level abnormality determination signal from the determination unit 145, it outputs an abnormality determination signal Err to a predetermined notification destination.

[0043] When comparing the phase of the resolver signal with the phase of the reference signal, if the resolver / digital conversion unit 110 is operating normally, φ = θ, and the phase of the resolver signal is the same as the phase of the reference signal. On the other hand, if the resolver / digital conversion unit 110 is malfunctioning, the resolver / digital conversion unit 110 will not be able to obtain a detection angle φ that matches the rotation angle of the resolver 10. As a result, a phase difference will occur between the resolver signal and the reference signal. Therefore, the abnormality monitoring unit 140 detects the above-mentioned phase difference and determines that the resolver / digital conversion unit 110 is in an abnormal state if the phase shift exceeds a preset threshold. This allows the system to detect whether the resolver / digital conversion unit 110 is functioning normally or abnormally and monitor its health.

[0044] [Effects obtained by the embodiment] According to Embodiments 1 and 2, the following effects can be obtained. The resolver signal output from the resolver 10, which uses a phase modulation method of two-phase excitation / two-phase output or two-phase excitation / one-phase output, is processed in the resolver / digital conversion unit 110. When generating a detection angle φ corresponding to the rotation angle θ of the resolver 10, the phase of the reference signal and the phase of the resolver signal are compared by the abnormality monitoring unit 140. If the phase difference exceeds a threshold, the resolver / digital conversion unit 110 is determined to be abnormal. This makes it possible to determine abnormalities in the resolver / digital conversion unit 110 in the angle detection device 100 using a phase-modulation resolver 10 without complicating the circuit configuration or signal line routing.

[0045] When a two-phase excitation / two-phase output phase-modulated resolver 10 outputs a first-phase resolver signal and a second-phase resolver signal, the abnormality monitoring unit 140 compares the phase of the reference signal with the first-phase resolver signal, and the abnormality monitoring unit 140 also compares the phase of the second-phase reference signal, which is shifted in phase by +90° relative to the reference signal, with the second-phase resolver signal. This makes it possible to determine abnormalities in the resolver / digital conversion unit 110 in the angle detection device 100, which uses a two-phase excitation / two-phase output phase modulation resolver 10, without complicating the circuit configuration or signal line routing.

[0046] The exclusive OR operation circuit calculates the exclusive OR of the inverted data of the most significant bit of the digital data constituting the reference signal and the binary data of the resolver signal. If the period of mismatch between the two inputs of the exclusive OR operation circuit is greater than a threshold, the determination unit determines that it is an abnormality and generates an abnormality determination signal. This makes it possible to digitally and accurately determine abnormalities in the resolver / digital conversion unit 110 of the angle detection device 100 using a phase-modulation resolver 10, with a simple circuit configuration and signal line routing. [Explanation of symbols]

[0047] 10 Resolver, 100 Angle detection device, 110 Resolver / digital conversion unit, 111a First multiplier, 111b Second multiplier, 112 Subtractor, 113 A / D conversion unit, 114 Control law, 115 Accumulator, 116 Adder, 120 Reference signal generation unit, 130 Excitation unit, 140 Anomaly monitoring unit, 141 Phase shift unit, 142, 142a, 142b Inverting unit, 143 Comparator, 143a First comparator, 143b Second comparator, 144 Exclusive OR operation circuit, 144a First exclusive OR operation circuit, 144b Second exclusive OR operation circuit, 145 Judgment unit, 145a First judgment unit, 145b Second judgment unit, 146 OR operation circuit, DR Resolver signal binary data, DR1 first phase resolver signal binary data, DR2 second phase resolver signal binary data, Dε digitized difference, θ rotation angle, φ detection angle, ε difference between the first intermediate signal and the second intermediate signal, ω angular velocity signal.

Claims

1. An angle detection method for detecting the rotation angle θ of a phase-modulated resolver (10), The function includes generating a phase output with respect to a reference signal generated by a reference signal generation unit (120), which has a phase shift corresponding to the rotation angle θ of the resolver (10), using a resolver / digital conversion unit (110), The excitation unit (130) generates a two-phase excitation signal corresponding to the phase output and supplies the excitation signal to the excitation winding of the resolver (10). The resolver signal output from the resolver (10) is processed in the resolver / digital conversion unit (110) to generate a detection angle φ corresponding to the rotation angle θ of the resolver (10), The abnormality monitoring unit (140) compares the phase of the reference signal and the phase of the resolver signal, and if the phase difference exceeds a threshold, it determines that the resolver / digital conversion unit (110) is abnormal. An angle detection method having the following characteristics.

2. The resolver signal of the first phase and the resolver signal of the second phase are output from the resolver (10). The phase of the reference signal and the first phase resolver signal are compared by the abnormality monitoring unit (140), The abnormality monitoring unit (140) compares the phase of the second phase reference signal, which is shifted in phase by +90° with respect to the aforementioned reference signal, with the phase of the second phase resolver signal. An angle detection method according to claim 1.

3. The digital data of the reference signal is generated by the reference signal generation unit (120), The resolver signal is converted into binary data by a comparator (143), The exclusive OR operation circuit (144) calculates the exclusive OR of the inverted phase data obtained from the most significant bit or the top two bits of the digital data constituting the reference signal and the binary data. If the period of mismatch between the two inputs of the exclusive OR operation circuit (144) is greater than a threshold, the determination unit (145) determines that it is an abnormality and generates an abnormality determination signal. An angle detection method according to claim 1.

4. An angle detection device for detecting the rotation angle θ of a phase-modulated resolver (10), A reference signal generation unit (120) that generates a reference signal, A resolver / digital conversion unit (110) processes the resolver signal output from the resolver (10) to generate a detection angle φ corresponding to the rotation angle θ of the resolver (10), and also generates a phase output having a phase shift corresponding to the rotation angle θ with respect to the reference signal. An excitation unit (130) generates a two-phase excitation signal corresponding to the phase output and supplies the excitation signal to the excitation winding of the resolver (10), An abnormality monitoring unit (140) compares the phase of the reference signal with the phase of the resolver signal, and determines that the resolver / digital conversion unit (110) is abnormal if the phase difference exceeds a threshold, An angle detection device having the following features.

5. The resolver (10) outputs a first-phase resolver signal and a second-phase resolver signal. The abnormality monitoring unit (140) compares the phase of the reference signal with the first phase resolver signal, and compares the phase of the second phase reference signal, which is shifted in phase by +90° with respect to the reference signal, with the second phase resolver signal. An angle detection device according to claim 4.

6. The reference signal generation unit (120) generates digital data of the reference signal, The aforementioned abnormality monitoring unit (140) A comparator (143) that converts the resolver signal into binary data, An exclusive OR operation circuit (144) that calculates the exclusive OR of the inverted phase data obtained from the most significant bit or the top two bits of the digital data constituting the reference signal and the binary data, The system includes a determination unit (145) that determines an abnormality and generates an abnormality determination signal if the period of mismatch between the two inputs of the exclusive OR operation circuit (144) is greater than a threshold, An angle detection device according to claim 4.

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