JP3248201B2 - Absolute value resolver backup method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolver for detecting an absolute position, and more particularly, to a backup method and apparatus at the time of a power failure.

[0002]

2. Description of the Related Art Conventionally, when an absolute position of an actuator is detected by connecting a resolver to the actuator, there is a method of obtaining the absolute position by the resolver even during a power failure. As a first example, as shown in FIG. 5, a resolver R and its associated excitation circuit L, R / D converter C,
There is a method in which the comparator P, the rotation amount storage circuit M, and the like are all operated by the backup battery B for backup, and the rotation amount is always stored. As a second example, as shown in FIG. 6, the excitation circuit L, the synchronous rectifier circuit S, and the rotation amount storage circuit M are backed up, and the signal of the resolver R is synchronously rectified and stored at the time of a power failure, and is started. There is a method of obtaining an absolute value by combining with the signal of the R / D converter C sometimes. As a third example, as shown in FIG. 7, a rotation detector K and a waveform shaping circuit H different from the resolver R are provided, and the rotation detector K is backed up to provide a rotation direction and rotation at the time of a power failure. There is a method of storing an amount and obtaining an absolute value at the time of startup by the same method as in the second example. Also,
As a fourth example, in a resolver with two-phase excitation and one-phase output, sine wave excitation is performed during energization, and pulse wave excitation is performed during a power failure. There is a method for obtaining the amount (for example, JP-A-63-214617).

[0003]

However, the first and the second
In the above example, the loss that occurs in the R / D converter and the excitation circuit is very large, and the battery required for backup requires a large capacity. Therefore, the space occupied by the battery becomes large, or the battery must be replaced frequently. There were drawbacks such as not being able to. In the third example, the use of a magnetoresistive element having a large internal resistance does not cause a problem of power consumption. However, the mechanism becomes large, and the temperature rise of the motor is limited by the operating temperature of the detecting element. There were drawbacks. In addition, in the fourth example, two excitation circuits that generate different waveforms, that is, a sine wave generator and a pulse generator, are required at the time of energization and at the time of power failure, respectively, so that the controller mechanism becomes large. Since the signal changes from a sine wave to a rectangular wave when the excitation circuit is switched, a detection error is likely to occur.
Therefore, there is a drawback that the positioning accuracy is reduced. SUMMARY OF THE INVENTION An object of the present invention is to provide a resolver that can be operated by a single excitation circuit both during energization and during a power outage, and can significantly reduce the power consumption of a backup circuit.

[0004]

In order to solve the above-mentioned problems, in the first aspect, a rotor provided with a one-phase excitation coil and a stator provided with two-phase detection coils having a phase difference of 90 ° are provided. a resolver having, in the resolver of the backup method of supplying power by a backup battery backup area including the excitation circuit of the exciting coil, wherein power is supplied at all times in the backup area, the excitation and generates a pulse wave by said excitation circuit By exciting the coil and holding the detection signal by a sample-and-hold circuit that samples in synchronization with the excitation circuit connected to the two-phase output detection coil, two sine wave signals having 90 ° phase differences are created. Connecting a comparator to the sample hold circuit, and counting and storing the output of the comparator by a rotation amount storage circuit. To make it to the sample hold circuit sine wave signal which is an output of the output to <br/> force the rotation angle by converting input to R / D converter to a digital signal to the controller, and the backup area the excitation circuit said sample and hold circuit and said comparator the only rotation amount storage circuit and, when power failure when energized even one of the exciting circuit
This is a method for backing up an absolute value resolver characterized by pulse excitation . According to a second aspect of the present invention, there is provided a backup method for an absolute value resolver according to the first aspect, wherein a multi-phase excitation pulse is generated by the excitation circuit, and the excitation coils of the plurality of resolvers are excited by excitation pulses having different phases. It is. According to a third aspect of the present invention, there is provided a backup area including a resolver including a rotor provided with a one-phase excitation coil and a stator provided with two-phase detection coils having different 90 ° phases, and an excitation circuit for the excitation coil. In a resolver backup device that supplies power from a backup battery , the backup area is always supplied with power, the excitation circuit generates a pulse wave to excite the excitation coil, and is connected to the two-phase output detection coil. By holding the detection signal by a sample and hold circuit that samples in synchronization with the excitation circuit, 90 °
Create two different sinusoidal signals in phase, to connect the comparator to said sample-and-hold circuit, so as to count and store the rotation amount storage circuit output of the comparator, a sine wave which is the output of the sample-and-hold circuit Input a signal and convert it to a digital signal to control the rotation angle.
An R / D converter for outputting to a roller , wherein the backup area includes only the excitation circuit, the sample and hold circuit, the comparator, and the rotation amount storage circuit ;
A backup device for an absolute value resolver characterized in that a pulse is excited by one excitation circuit both during energization and during a power failure . According to a fourth aspect of the present invention, there is provided a backup device for an absolute value resolver according to the third aspect, wherein a multi-phase excitation pulse is generated by the excitation circuit, and the excitation coils of the plurality of resolvers are excited by excitation pulses having different phases. It is.

[0005]

[Function] Since the exciting coil of the resolver in the backup area is pulse-wave-excited by the exciting circuit, the power consumption is very small as compared with the case of exciting by the ordinary sine wave, and the life of the backup battery is significantly prolonged. Can be. In addition, the frequency of the pulse wave excitation is changed according to the speed of the rotor of the resolver, and the detection signal is held by a sample-and-hold circuit synchronized with the excitation circuit. Waves are obtained. In addition, when exciting a plurality of resolvers, multi-phase pulse excitation is performed by an excitation circuit, and each excitation coil extracts and excites a pulse having a different phase, so that the voltage fluctuation of the backup battery can be reduced. Life can be extended.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 is a block diagram showing an embodiment of the present invention.
Is a rotor provided with a one-phase excitation coil 11 fixed to a rotation shaft to be detected, and a two-phase detection coil 1 having a 90 ° phase difference.
And a stator provided with 2a and 12b. The exciting coil 11, as shown in FIG. 2 (a), are to be pulsed excitation by the excitation circuit 2 which generates an excitation pulse V _i at a predetermined timing. A sample-and-hold circuit 3 that outputs in synchronization with the excitation circuit 2 is connected to the detection coils 12a and 12b, and a sine-wave-excited n-phase resolver signal generated in the excitation coil 11 when the rotor rotates n times is provided. As shown in FIG. 2B, sine wave signals V _0a and V _0b having the same mechanical angle 2π as the signal after synchronous rectification and having n peaks and different phases by 90 ° are obtained. A comparator 4 is connected to the sample and hold circuit 3, and the sine wave signals V _0a and V _0b . A and B-phase signals V _a and V _b at rectangular wave positions as shown in FIG. 2C corresponding to the rotation signal N are output to the rotation amount storage circuit 5 connected to the comparator 4.
Is stored as Further, a resolver / digital (R / D) converter 6 is connected to the sample hold circuit 3, and a sine wave signal V output from the sample hold circuit 3 is output.
_0a and V _0b are converted into digital signals to output the rotation angle θ. The rotation amount signal N of the rotation amount storage circuit 5 and the rotation angle θ output from the R / D converter 6 are input to the controller 7, and the absolute value signal of the resolver 1 is obtained. ± 5 V or ± 12 for the R / D converter 6 and the controller 7
V of the main DC power supply 8 for applying a DC voltage of V
And the negative side is connected by a connection line 82.
Further, a backup area A composed of an excitation circuit 2, a sample and hold circuit 3, a comparator 4, and a rotation amount storage circuit 5
The main DC power supply 8 is connected to the + side via a connection line 84 via a diode 83 and connected to the − side via a connection line 86 via a diode 85 to supply power.
A backup battery 9 is provided in parallel with the main DC power supply 8, the + side of the backup battery 9 is connected to a connection line 84 via a diode 91, and the − side of the backup battery 9 is connected to a connection line 8 via a diode 92.
6 is connected. Therefore, normally, a DC voltage is applied to the backup area A including the R / D converter 6, the controller 7, the excitation circuit 2, the sample and hold circuit 3, the comparator 4, and the rotation amount storage circuit 5 by the main DC power supply 8. Sometimes, when the main DC power supply 8 shuts down or a voltage drop occurs, a DC voltage is applied to the backup area A by the backup battery 8 to perform backup.

Here, the life of the backup battery 8 for the backup area A is substantially determined by the power consumption of the excitation circuit 2. However, in this case, since the excitation circuit 2 is excited by the pulse wave, the power consumption is very small as compared with the conventional sine wave excitation. For example, in the case of sine wave excitation, the voltage and current waveforms are as shown in FIG. 3A, and in the case of pulse wave excitation with a 5% duty, the voltage and current waveforms are as shown in FIG. 6B. When the excitation voltage is 6 V and the detection voltage is 1 V, the detection current of the sine wave excitation is 20 m
A, while the power consumption is 252 mW, the detection current of the pulse wave excitation is 5 mA, the power consumption is 4.5 mW,
The power consumption of the pulse wave excitation was about 1/50 that of the sine wave excitation. Therefore, the life of the backup battery can be significantly extended by exciting the excitation circuit with a pulse wave. As shown in FIG. 4, when a plurality of resolvers 1 are backed up by one backup battery 8, the excitation pulse is generated in the excitation circuit 2 by using a polyphase pulse generator. Since each excitation coil 11 extracts and excites a pulse having a different phase, the voltage fluctuation of the power supply can be suppressed small, and the life of the backup battery 8 used as the power supply can be extended.

[0008]

As described above, according to the present invention, the following effects can be obtained. (1) Since the excitation is performed by the pulse wave, the loss due to the excitation is very small as compared with the conventional sine wave excitation, the power consumption in the backup area is reduced, and in the case of a normal resolver,
Several dry batteries provided in parallel with the main DC power supply can provide sufficient backup. (2) By changing the frequency of the pulse wave excitation in accordance with the speed of the rotating shaft, two stable sine waves are always obtained by the sample and hold circuit, so that stable positioning accuracy is obtained. (3) When exciting a plurality of resolvers, multi-phase pulse excitation is performed by an excitation circuit, and each excitation coil extracts and excites a pulse having a different phase, so that the voltage fluctuation of the backup battery can be reduced. Battery life can be extended.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an excitation pulse and A- and B-phase sine wave signals.

FIG. 3 is a diagram illustrating a comparison between sine wave excitation and pulse wave excitation.

FIG. 4 is a block diagram showing another embodiment.

FIG. 5 is a block diagram showing a conventional example.

FIG. 6 is a block diagram showing a conventional example.

FIG. 7 is a block diagram showing a conventional example.

[Explanation of symbols]

1 Resolver 2 Excitation circuit 3 Sample hold circuit 4 Comparator 5 Rotation amount storage circuit 6 R / D converter 7 Controller 8 Main DC power supply 9 Backup battery

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-214617 (JP, A) JP-A-1-85539 (JP, A) JP-A-62-133315 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01D 5/00-5/64 G01B ⁷ /00-7/32 G01P 1/00-3/80

Claims (4)

(57) [Claims] A rotor provided with a one-phase excitation coil;
° a resolver including a stator having a detecting coil of the two different phases phases, the resolver backup method of supplying power by a backup battery backup area including the excitation circuit of the exciting coil, the backup area Power is supplied constantly, a pulse wave is generated by the excitation circuit to excite the excitation coil, and a detection signal is held by a sample and hold circuit that samples in synchronization with the excitation circuit connected to the two-phase output detection coil. by, create two different sinusoidal signals 90 ° phase, the connect comparator sample and hold circuit, the count was provided to store the rotation amount storage circuit output of said comparator, said sample and hold circuit Output the sine wave signal to R
/ D to converter type is converted into a digital signal and outputs the rotation angle to the controller, the a backup area and the excitation circuit said sample-and-hold circuit and said comparator by said rotation amount storage circuit and also during power failure during energization one
A pulse excitation by the two excitation circuits . 2. The absolute value resolver backup method according to claim 1, wherein the excitation circuit generates a multi-phase excitation pulse by the excitation circuit, and the excitation coils of the plurality of resolvers are excited by excitation pulses having different phases. 3. A rotor provided with a one-phase excitation coil and 90 °
In a backup device for a resolver that supplies power by a backup battery to a backup area including a resolver including a stator provided with two-phase detection coils having different phases and an excitation circuit of the excitation coil , the backup area is always in the backup area. Feeding, generating a pulse wave by the excitation circuit to excite the excitation coil, and holding a detection signal by a sample and hold circuit that samples in synchronization with the excitation circuit connected to the two-phase output detection coil. Thus, two sine wave signals having phases different from each other by 90 ° are created, a comparator is connected to the sample hold circuit, the output of the comparator is counted and stored by a rotation amount storage circuit, and the output of the sample hold circuit is output. Control the rotation angle with a sine wave input signal is converted into a digital signal And an R / D converter to <br/> force output to over La, the a backup area the excitation circuit said sample-and-hold circuit and said comparator by said rotation amount storage circuit and, stopping even during energization
A backup device for an absolute value resolver, wherein a pulse excitation is performed by one excitation circuit even when power is applied . 4. The absolute value resolver backup device according to claim 3, wherein the excitation circuit generates a multi-phase excitation pulse by the excitation circuit, and the excitation coils of the plurality of resolvers are excited by excitation pulses having different phases.