JP5349637B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to an apparatus for detecting a rotation angle of a motor or the like using a resolver.

  The resolver is a rotation angle sensor including an exciting coil and two output coils around a rotor connected to a shaft. In addition to the resolver, the rotary angle sensor has a rotary encoder. However, the rotary encoder uses optical elements and magnetoresistive elements, so it is easily affected by temperature, noise, dust, etc. Inferior. On the other hand, a resolver is basically composed only of a coil and an iron core, and does not use the above-described elements. Therefore, it can be used under severe environmental conditions, for example, for motors and steering in automobiles. It is used to detect the rotation angle.

The principle of the resolver will be briefly explained. When a sine wave signal is applied to the primary excitation coil, a two-phase voltage that is amplitude-modulated in a sine wave shape is induced in each output coil on the secondary side according to the rotation angle of the shaft. That is, one output coil outputs a signal whose amplitude peak value changes with a sin function, and the other output coil outputs a signal whose amplitude peak value changes with a cos function. Therefore, the rotation angle of the shaft can be calculated by detecting the amplitude of each output signal and obtaining its tan ⁻¹ .

  In the resolver as described above, when the wire harness connecting the resolver and the excitation signal generating means is in electrical contact with a grounded part such as an automobile body or an interior product, the excitation coil and the excitation signal generating means A ground fault occurs between the two. When such a ground fault occurs, the current continues to flow through the excitation signal generating means and the exciting coil of the resolver, so that the circuit element may be destroyed or the coil may be disconnected by heat. In the following Patent Document 1, when a ground fault occurs, the level of the excitation signal output from the excitation signal generating means is kept low, and the current continues to flow to the excitation signal generating means and the excitation coil due to the ground fault. However, since the current value is small, a technique is disclosed in which the circuit element of the excitation signal generating means is not destroyed by heat or the excitation coil is not broken by heat (see Patent Document 1).

JP 2010-14509 A

  However, in Patent Document 1, although the excitation signal generating means can be protected in the event of a ground fault, a current flows through the excitation signal generating means and the excitation coil of the resolver in the event of a short circuit with the power supply line. Since it will be in the state which continues, there exists a possibility that destruction of an element and the disconnection of a coil may generate | occur | produce.

  In view of the above-described problems, the present invention can prevent element destruction and coil disconnection even when an abnormality such as a ground fault or a power fault occurs between the excitation coil of the resolver and the excitation signal generation means. An object of the present invention is to provide a rotation angle detection device that can be used.

A rotation angle detection device according to the present invention includes a resolver provided with an excitation coil and an output coil around a rotor connected to a shaft, excitation signal generation means for generating an excitation signal, and an excitation signal output to the excitation coil. An excitation signal output means, a rotation angle calculation means for detecting an amplitude of an output signal of the output coil, and calculating a rotation angle of the shaft based on the detected value, and the excitation coil and the excitation signal output means. the excitation signal abnormality detecting means for detecting that an abnormality occurs during, when the excitation signal abnormality detecting means detects abnormality, comprising an excitation signal output stop means for stopping output of the excitation signal, the excitation signal In the state where the output of the excitation signal is stopped by the output stop means, the output signal from the excitation signal output means is set to a potential at which no abnormality is determined by the excitation signal abnormality detection means. It is obtained by way.
The rotation angle detection device according to the present invention includes a resolver provided with an excitation coil and an output coil around a rotor connected to a shaft, excitation signal generation means for generating an excitation signal, and an excitation signal as the excitation coil. Excitation signal output means for outputting to the output, rotation angle calculation means for detecting the amplitude of the output signal of the output coil and calculating the rotation angle of the shaft based on the detected value, the excitation coil and the excitation signal output means An excitation signal abnormality detecting means for detecting an abnormality between the excitation signal output detecting means, an excitation signal output stopping means for stopping the output of the excitation signal when the excitation signal abnormality detecting means detects an abnormality, and a rotation angle. Power supply voltage detection means for detecting the power supply voltage of the detection device, and when the power supply voltage detection means detects a voltage outside the operating voltage range of the excitation signal generation means, the excitation signal It is obtained to perform the output stop of the excitation signal by the force stopping unit.

According to the present invention, when an abnormality such as a ground fault or a power fault occurs between the excitation coil of the resolver and the excitation signal output means, current does not continue to flow through the excitation signal output means or the excitation coil. When the circuit element of the signal output means is not destroyed by heat or the excitation coil is disconnected by heat , the excitation signal output is stopped when the excitation signal output is stopped by the excitation signal output stop means. Since the output signal from the means is set to a potential at which the excitation signal abnormality detecting means does not determine abnormality, the abnormality can be reliably detected even when the excitation signal output is stopped .
Further, according to the present invention, when the power supply voltage detecting means detects a voltage outside the operating voltage range of the excitation signal generating means, the excitation signal output is stopped by the excitation signal output stopping means. It is possible to reliably prevent breakage of the circuit elements of the means due to heat and disconnection due to heat of the exciting coil .

The connection diagram which shows the structural example of the rotation angle detection apparatus in embodiment which concerns on this invention. The cross-sectional view which shows schematic structure of the resolver in embodiment which concerns on this invention. The connection diagram which shows the structural example of the excitation signal production | generation means in embodiment which concerns on this invention. The connection diagram which shows the structural example of the excitation signal abnormality detection means in embodiment which concerns on this invention. The connection diagram which shows the structural example of the excitation signal output stop means in embodiment which concerns on this invention. The connection diagram which shows the structural example of the excitation signal output means in embodiment which concerns on this invention. The curve figure which shows each waveform of the excitation signal in the normal state in embodiment which concerns on this invention. The curve figure which shows the signal waveform applied to the exciting coil in the normal state in embodiment which concerns on this invention. The curve figure which shows the signal waveform induced in the output coil in the normal state in embodiment which concerns on this invention.

Embodiment 1 FIG.
FIG. 1 shows a configuration example of a rotation angle detection device according to Embodiment 1 of the present invention. The rotation angle detection device according to the present invention includes a resolver 1 and a control unit 2.

  The resolver 1 includes a primary side excitation coil L1 and secondary side output coils L2 and L3. These coils L <b> 1 to L <b> 3 are arranged around the rotor (rotor) 11.

  FIG. 2 shows a schematic structure of the resolver 1. The rotor 11 is connected to the shaft 13 and rotates together with the shaft 13. The shaft 13 is a rotating shaft such as a motor or a shaft connected thereto. A stator (stator) 12 is provided around the rotor 11. The stator 12 is formed with magnetic poles (not shown) at equal intervals in the circumferential direction, and coils L1 to L3 are wound around the magnetic poles.

  The control unit 2 detects the excitation signal generation means 21 that generates the excitation signal, the excitation signal output means 22 that outputs the generated excitation signal to the excitation coil L1, and the amplitude of the output signal of the output coils L2 and L3. Rotation angle calculation means 23 for calculating the rotation angle based on the detected value, excitation signal abnormality detection means 24 for detecting that an abnormality has occurred between the excitation coil L1 and the excitation signal output means 22, and excitation signal abnormality detection And excitation signal output stopping means 25 for stopping the output of the excitation signal when the means 24 detects an abnormality.

  The signal output from the excitation signal output means 22 is applied to one terminal U1 of the excitation coil L1 of the resolver 1 and the other terminal U2 of the excitation coil L1. The excitation signal abnormality detection means 24 monitors the voltage between the terminals U1 and U2, that is, the voltage across the excitation coil L1 of the resolver 1.

  The rotation angle calculation means 23 outputs a sin phase signal output from the output coil L2, that is, an output signal whose amplitude varies with the sin function with the rotation angle of the shaft, and a cos phase signal output from the output coil L3, that is, the shaft. The rotation angle of the shaft is calculated from the output signal whose amplitude varies with the cos function along with the rotation angle of the shaft. S1 and S3 are terminals of the output coil L2, and S2 and S4 are terminals of the output coil L3.

  FIG. 3 shows a configuration example of the excitation signal generation means 21. The excitation signal generating means 21 includes an operational amplifier OP1 and resistors R1 and R2 connected to the inverting input terminal (− terminal) of the operational amplifier OP1. Vd is a power supply voltage of the rotation angle detection device. The reference signal and the output signal 221 are input to the inverting input terminal of the operational amplifier OP1 via the resistor R1 and the resistor R2, respectively. An offset signal is input to the non-inverting input terminal (+ terminal) of the operational amplifier OP1. The operational amplifier OP1 outputs an excitation signal 211 obtained by adding an offset signal to a signal obtained by amplifying the reference signal.

  Further, it includes an operational amplifier OP2, an inverting circuit INV1 connected to the inverting input terminal (− terminal) of the operational amplifier OP2, a resistor R3, and a resistor R4. Vd is a power supply voltage of the rotation angle detection device. The reference signal whose phase is inverted by 180 ° by the inverting circuit INV1 through the resistor R4 and the output signal 222 through the resistor R4 are input to the inverting input terminal of the operational amplifier OP2. An offset signal is input to the non-inverting input terminal (+ terminal) of the operational amplifier OP2. The operational amplifier OP2 outputs an excitation signal 212 obtained by adding an offset signal to a signal obtained by amplifying a reference signal having an inverted phase.

  FIG. 4 shows a configuration example of the excitation signal abnormality detection means 24. The excitation signal abnormality detection means 24 includes a comparator COM1, a resistor R5 connected to the inverting input terminal (− terminal) of the comparator COM1, and resistors R6 and R7 connected to the non-inverting input terminal (+ terminal) of the comparator COM1. It has. The voltage of one terminal U1 of the exciting coil L1 is input to the inverting input terminal of the comparator COM1 through the resistor R5. A voltage obtained by dividing the power supply voltage of the rotation angle detector by resistors R6 and R7 is input to the non-inverting input terminal of the comparator COM1. The comparator COM1 outputs a ground fault detection signal that becomes “H” when the voltage at one terminal U1 of the exciting coil L1 becomes lower than the voltage value divided by the resistors R6 and R7.

  The comparator COM2, the resistor R5 connected to the non-inverting input terminal (+ terminal) of the comparator COM2, and the resistors R8 and R9 connected to the inverting input terminal (− terminal) of the comparator COM2. The voltage of one terminal U1 of the exciting coil L1 is input to the non-inverting input terminal of the comparator COM2 via the resistor R5. A voltage obtained by dividing the power supply voltage of the rotation angle detection device by the resistors R8 and R9 is input to the inverting input terminal of the comparator COM2. The comparator COM2 outputs a power fault detection signal that becomes “H” when the voltage at one terminal U1 of the exciting coil L1 becomes higher than the voltage value divided by the resistors 8 and R9.

  In the above description, the excitation signal abnormality detection means for one terminal U1 of the excitation coil L1 has been described. However, the ground fault detection and the power fault detection can be performed by the same means for the other terminal U2 of the excitation coil L2.

  FIG. 5 shows a configuration example of the excitation signal output stop means 25. The excitation signal output stop means 25 includes transistors Q1 and Q2 connected to the ground fault detection signal. The collector of the transistor Q1 is connected to the excitation output stop signal 251 and the emitter is grounded. A ground fault detection signal is input to the base of the transistor Q1. When the ground fault detection signal is “H”, the transistor Q1 is turned on, and when the ground fault detection signal is “L”, the transistor Q1 is turned off. The collector of the transistor Q2 is connected to the excitation output stop signal 252 and the emitter is grounded. A ground fault detection signal is input to the base of the transistor Q2. When normal (when the ground fault detection signal is “L”), the transistor Q2 is turned off, and when abnormal (when the ground fault detection signal is “H”), the transistor Q2 is turned on.

  In addition, an inverter circuit INV2 connected to the power supply detection signal and transistors Q3 and Q4 connected to the output of the inverter circuit INV2 are provided. The collector of the transistor Q3 is connected to the power supply voltage of the rotation angle detection device, and the emitter is connected to the excitation output stop signal 253. The signal of the inverting circuit INV2 is input to the base of the transistor Q3. When the power supply detection signal is “H”, the transistor Q3 is turned on. When the power supply detection signal is “L”, the transistor Q3 is turned off. The collector of the transistor Q4 is connected to the power supply voltage of the rotation angle detector, and the emitter is connected to the excitation output stop signal 254. The signal of the inverting circuit INV2 is input to the base of the transistor Q4. When normal (when the power fault detection signal is “L”), the transistor Q4 is turned off, and when abnormal (when the power fault detection signal is “H”), the transistor Q4 is turned on.

  FIG. 6 shows a configuration example of the excitation signal output means 22. The excitation signal output means 22 is connected to the diodes D1 and D2 connected to the excitation signal 211, the excitation output stop signal 251 connected to the anode of the diode D1, the resistor R10, the transistor Q5, and the emitter side of the transistor Q5. Resistor R11, excitation output stop signal 253 connected to the cathode of diode D2, resistor R12, transistor Q6, and resistor R13 connected to the collector side of transistor Q6. The emitter of the transistor Q5 via the resistor R11 and the collector of the transistor Q6 via the resistor R13 are connected to one terminal U1 of the exciting coil L1. At the time of abnormality (when the ground fault detection signal is “H” or the sky fault detection signal is “H”), the transistors Q5 and Q6 are turned off.

  Also, the diodes D3 and D4 connected to the excitation signal 212, the excitation output stop signal 252 connected to the anode of the diode D3, the resistor R14, the transistor Q7, and the resistor R15 connected to the emitter side of the transistor Q7 , An excitation output stop signal 254 connected to the cathode of the diode D4, a resistor R13, a transistor Q8, and a resistor R17 connected to the collector side of the transistor Q8. The emitter of the transistor Q7 via the resistor R15 and the collector of the transistor Q8 via the resistor R17 are connected to the other terminal U2 of the exciting coil L1. At the time of abnormality (when the ground fault detection signal is “H” or the sky fault detection signal is “H”), the transistors Q7 and Q8 are turned off.

Next, the operation of the rotation angle detection device described above will be described.
First, the operation in a normal state where no abnormality has occurred will be described. FIG. 7 shows respective signal waveforms applied from the excitation signal output means 22 to the excitation coil L1. A signal VU1 shown in FIG. 7A is an output signal 221 output from the excitation signal output means 22, and is in phase with the excitation signal 211. A signal VU2 shown in FIG. 7B is an output signal 222 output from the excitation signal output means 22, and is in phase with the excitation signal 212. The excitation signal 211 is a signal obtained by adding an offset signal Vo to a reference signal (in this description, the reference signal is a sine wave signal), and the excitation signal 212 is a signal having a phase opposite to that of the reference signal. This is the added signal.

  As described above, the signal VU1 is applied to one terminal U1 of the exciting coil L1, and the signal VU2 is applied to the other terminal U2 of the exciting coil L1. Therefore, a signal VL1 (= VU1-VU2) as shown in FIG. 8 is applied to both ends of the exciting coil L1 of the resolver 1. The amplitude of the signal VL1 is twice the amplitude of the signals VU1 and VU2. As shown in FIG. 7, by setting the signals VU1 and VU2 to signals that are raised by the offset signal Vo, a signal having a large amplitude as shown in FIG. 8 can be applied to the exciting coil L1. As a result, the amplitude of the signal output from the output coils L2 and L3 also increases, so that the influence of noise is reduced and the detection accuracy can be increased.

When the shaft 13 rotates while the signal VL1 of FIG. 8 is applied to the excitation coil L1, the output coil L2 is amplitude-modulated so that the peak value of the amplitude changes with a sin function as shown in FIG. The signal VL2 is induced. This signal VL2 is input to the rotation angle calculation means 23 via terminals S1 and S3. On the other hand, as shown in FIG. 9B, an amplitude-modulated signal VL3 whose peak value of amplitude changes with a cos function is induced in the output coil L3. This signal VL3 is input to the rotation angle calculation means 23 via terminals S2 and S4. The rotation angle calculation means 23 samples the sin phase signal and the cos phase signal, and detects the amplitude value (peak value) of each signal. Then, based on the detected amplitude value, the rotation angle of the shaft 13 is calculated. That is, the amplitude ratio A / B is calculated from the amplitude value A of the sin phase and the amplitude value B of the cos phase at each sampling time to obtain tan ⁻¹ (A / B), and the rotation angle θ corresponding to the value is obtained. Is calculated.

  Next, the operation when an abnormality occurs between the excitation coil L1 and the excitation signal output means 22 will be described. Below, the case where the terminal U2 of the exciting coil L1 is grounded is given as an example.

  When the other terminal U2 of the exciting coil L1 is grounded, the signal VU2 = 0, and the signal VL1 (= signal VU1-signal VU2) applied to the exciting coil L1 becomes the signal VU1. Here, since the terminal U2 is in the ground fault state, a large current based on the voltage VL1 continues to flow through the excitation signal output means 22 and the excitation coil L1. For this reason, the circuit element of the excitation signal output means 22 may be destroyed by heat, or the excitation coil L1 may be disconnected by heat.

  In the present invention, when the terminal U2 is grounded, the excitation signal abnormality detecting means 24 detects the abnormality and the excitation signal output stopping means 25 outputs the excitation output stop signal, so that the excitation signal output means 22 It prevents element destruction and disconnection of the exciting coil L1. The details will be described below.

  As described above, the signals VU1 and VU2 between the excitation signal output means 22 and the excitation coil L1 are constantly monitored by the excitation signal abnormality detection means 24, and the signal VU2 is detected by a predetermined threshold (resistors R6 and R7). When the voltage value is smaller than the divided voltage value, “H” is output from the excitation signal abnormality detection means 24 to the ground fault detection signal. In the excitation signal output stop means 25, when the ground fault detection signal becomes “H”, the transistors Q1 and Q2 connected to the excitation output stop signal 251 and the excitation output stop signal 252 are turned on. For this reason, when the excitation output stop signal 251 and the excitation output stop signal 252 become “L”, the transistors Q5 and Q7 of the excitation signal output means 22 are turned off. Further, since the terminal U2 is grounded, the transistors Q6 and Q8 of the excitation signal output means 22 are also turned off. Therefore, since there is no path for current to flow through the terminals U1 and U2 of the exciting coil L1, it is possible to prevent the elements of the exciting signal output means 22 from being broken and the exciting coil L1 from being disconnected.

  In the first embodiment, the case where the terminal U2 is grounded has been described. However, when the terminal U1 is grounded, the transistors Q5 and Q7 of the excitation signal output unit 22 are turned off by the same principle. It is possible to prevent destruction of the elements of the excitation signal output means 22 and disconnection of the excitation coil L1.

Next, the case where the terminal U1 of the exciting coil L1 has a power fault will be described.
When the other terminal U2 of the exciting coil L1 is grounded, the signal VU1 = Vd (the power supply voltage of the rotation angle detecting device), and the signal VL1 (= signal VU1-signal VU2) applied to the exciting coil L1 is the rotation angle. This is a value obtained by subtracting the signal VU2 from the power supply voltage of the detection device. Here, since the terminal U1 is in a power supply state, a large current based on the voltage VL1 continues to flow through the excitation signal output means 22 and the excitation coil L1. For this reason, the circuit element of the excitation signal output means 22 may be destroyed by heat, or the excitation coil L1 may be disconnected by heat.

  In the present invention, when the terminal U1 has a power fault, the excitation signal abnormality detection means 24 detects an abnormality, and the excitation signal output stop means 25 outputs an excitation output stop signal. It prevents element destruction and disconnection of the exciting coil L1. The details will be described below.

  As described above, the signals VU1 and VU2 between the excitation signal output means 22 and the excitation coil L1 are constantly monitored by the excitation signal abnormality detection means 24, and the signal VU2 is detected by a predetermined threshold (resistors R8 and R9). When the voltage value is larger than the divided voltage value, “H” is output from the excitation signal abnormality detection means 24 to the power supply detection signal. In the excitation signal output stop means 25, when the power fault detection signal becomes “H”, the transistors Q3 and Q4 connected to the excitation output stop signal 253 and the excitation output stop signal 254 are turned on. For this reason, when the excitation output stop signal 253 and the excitation output stop signal 254 become “H”, the transistors Q6 and Q8 of the excitation signal output means 22 are turned off. In addition, since the terminal U1 has a power fault, the transistors Q5 and Q7 of the excitation signal output means 22 are also turned off. Therefore, since there is no path for current to flow through the terminals U1 and U2 of the exciting coil L1, it is possible to prevent the elements of the exciting signal output means 22 from being broken and the exciting coil L1 from being disconnected.

  In the first embodiment, the case where the terminal U1 has a power fault has been described. However, when the terminal U2 has a power fault, the transistors Q6 and Q8 of the excitation signal output unit 22 are turned off by the same principle. It is possible to prevent destruction of the elements of the excitation signal output means 22 and disconnection of the excitation coil L1.

  In the present invention, various embodiments other than those described above can be adopted. For example, in the first embodiment, the example in which the abnormality detection circuit shown in FIG. 4 is provided as the excitation signal abnormality detection unit 24 is described. For example, when the signals VU1 and VU2 are A / D input to an arithmetic unit such as a microcomputer and become a value smaller than a predetermined threshold value, “H” is output as a ground fault detection signal. It may be configured to output “H” as a power detection signal when the value becomes large.

  In the first embodiment, the example in which the excitation output stop circuit shown in FIG. 5 is provided as the excitation signal output stop unit 25 is described. However, the unit for stopping the output of the excitation signal is not limited to this. For example, the ground fault detection signal and the power fault detection signal may be connected by an OR circuit, and when ground fault detection or power fault detection is performed, the transistors Q1, Q2, Q3, and Q4 may all be turned on. Further, the transistors Q1, Q2, Q3, and Q4 may be configured to use switching elements other than the transistors.

Embodiment 2. FIG.
In the state where the excitation output stop signal is output to the excitation signal output unit 22 of the above embodiment, the excitation signal output unit 22 can connect the offset signal to the terminals U1 and U2 of the excitation coil L1. The excitation signal abnormality detecting means 24 may be set to a potential that does not determine abnormality.

  In this way, even when the excitation signal output stop means 25 stops output of the excitation signal, the excitation coil and excitation signal output are used so that the excitation signal abnormality detection means 24 does not determine abnormality. When an abnormality occurs with the means 22, the excitation signal abnormality detecting means 24 can detect the abnormality.

Embodiment 3 FIG.
The excitation signal abnormality detection means may detect a state between the excitation coil and the excitation signal output means even in a state where the excitation signal output is stopped by the excitation signal output stop means. Good.

  By doing so, it becomes possible to always detect the state between the excitation coil and the excitation signal output means.

Embodiment 4 FIG.
Even after the abnormality is detected by the excitation signal abnormality detection means 24, when the state between the excitation coil and the excitation signal output means 22 is detected and the normal state is restored from the abnormal state, the excitation signal output stop means 25 is detected. Release the excitation signal output stop by.

  In this way, even after the abnormality is detected by the excitation signal abnormality detection means 24, when the state between the excitation coil and the excitation signal output means 22 returns from the abnormal state to the normal state, the excitation signal is output. You can resume.

Embodiment 5 FIG.
The excitation signal stop means of the above embodiment is provided with power supply voltage detection means for detecting the power supply voltage of the rotation angle detection device, and the power supply voltage of the rotation angle detection device detects a voltage outside the operating voltage range of the excitation signal generation means. In this case, the excitation output stop signal may be output.

  By doing in this way, even when the power supply voltage of the rotation angle detecting device becomes a voltage outside the operating voltage range of the excitation signal generating means, the excitation signal output can be stopped, and the excitation signal output means and the excitation coil can be stopped. Therefore, the circuit element of the excitation signal output means can be prevented from being damaged by heat, the disconnection of the excitation coil from heat, and the like.

  It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Resolver, 2 Control part, 11 Rotor, 12 Stator, 13 axis | shaft, 21 Excitation signal production | generation means, 22 Excitation signal output means, 23 Rotation angle calculation means, 24 Excitation signal abnormality detection means, 25 Excitation signal output stop means, L1 Excitation Coil, L2 output coil, L3 output coil, one terminal of U1 excitation coil, the other terminal of U2 excitation coil, one terminal of S1 output coil L2, one terminal of S2 output coil L3, the other of S3 output coil L2 , S4, the other terminal of the output coil L3.

Claims (4)

A resolver provided with an excitation coil and an output coil around a rotor connected to a shaft; an excitation signal generation means for generating an excitation signal; an excitation signal output means for outputting an excitation signal to the excitation coil; and the output coil And detecting that an abnormality has occurred between the excitation coil and the excitation signal output means, and a rotation angle calculation means for calculating the rotation angle of the shaft based on the detected value. Excitation signal abnormality detection means and excitation signal output stop means for stopping the output of the excitation signal when the excitation signal abnormality detection means detects an abnormality, and the excitation signal output stop means outputs the excitation signal. in the state where the stop, the output signal from the excitation signal output means, the rotation angle detection instrumentation, characterized in that to the no abnormality judgment potential at said excitation signal abnormality detecting means . The excitation signal abnormality detection means detects the state between the excitation coil and the excitation signal output means even when the excitation signal output is stopped by the excitation signal output stop means. The rotation angle detection device according to claim 1 . The excitation signal abnormality detection means detects the state between the excitation coil and the excitation signal output means even after detecting the abnormality, and when the abnormality signal returns to the normal state, the excitation signal output stop means The rotation angle detection device according to claim 1 , wherein the output stop of the signal is released. A resolver provided with an excitation coil and an output coil around a rotor connected to a shaft; an excitation signal generation means for generating an excitation signal; an excitation signal output means for outputting an excitation signal to the excitation coil; and the output coil And detecting that an abnormality has occurred between the excitation coil and the excitation signal output means, and a rotation angle calculation means for calculating the rotation angle of the shaft based on the detected value. Excitation signal abnormality detection means, excitation signal output stop means for stopping the output of the excitation signal when the excitation signal abnormality detection means detects an abnormality, and power supply voltage detection means for detecting the power supply voltage of the rotation angle detection device And when the power supply voltage detecting means detects a voltage outside the operating voltage range of the excitation signal generating means, the excitation signal output stopping means stops the output of the excitation signal. Rotation angle detecting apparatus according to claim Ukoto.

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