JPH055629A - Absolute value resolver backup method and apparatus - Google Patents

Abstract

(57) [Summary] [Structure] A rotor provided with a one-phase exciting coil 11 and 90
The main DC power supply 8 always supplies electric power to the backup area including the resolver 1 having a stator provided with two-phase detection coils 12 having different phases and the excitation circuit 2 of the excitation coil 12, and A backup battery 9 is provided in parallel with the DC power source 8, a pulse wave is generated by the exciting circuit 2 to excite the exciting coil 11, and the exciting circuit 2 is connected to the two-phase output detecting coil 12. By holding the detection signal by the sample-hold circuit 3 that samples in synchronization, two sine wave signals having different 90 ° phases are obtained. [Effect] Since the excitation is performed with a pulse wave, the loss due to the excitation is very small compared to the conventional sinusoidal excitation, the power consumption in the backup area is small, and in the case of an ordinary resolver, it is installed in parallel with the main DC power supply. Only a few batteries will provide sufficient backup.

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 device for a power failure.

[0002]

2. Description of the Related Art Conventionally, when a resolver is coupled to an actuator to detect the absolute position of the actuator, there is a method of obtaining the absolute position by the resolver even during a power failure. As a first example thereof, as shown in FIG. 5, a resolver R, an exciting circuit L associated therewith, an 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 and backed up to always store the rotation amount. As a second example, as shown in FIG. 6, the excitation circuit L, the synchronous rectification 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 the startup is performed. Sometimes there is a method of obtaining an absolute value by combining with the signal of the R / D converter C. Further, as a third example, as shown in FIG. 7, a rotation detector K and a waveform shaping circuit H, which are separate from the resolver R, are provided, and the rotation detector K is backed up to rotate in the rotation direction and rotation at the time of power failure. There is a method of storing the amount and obtaining the absolute value at the time of startup by the same method as 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, pulse wave excitation is performed during power failure, and the resolver rotation direction and rotation are determined based on the temporal timing of the excitation pulse and the detection pulse. There is a method for obtaining the amount (for example, JP-A-63-214617).

[0003]

However, the first and second problems
In the above example, the loss generated in the R / D converter and the excitation circuit is very large, and a large capacity is required for the battery required for backup, so the space occupied by the battery becomes large and the battery must be replaced frequently. There were drawbacks such as not becoming. Further, in the third example, if a magnetoresistive effect element having a large internal resistance is used, the problem of power consumption does not occur, but the mechanism becomes large and the temperature rise of the motor is limited by the operating temperature of the detection element. There was a drawback. In addition, in the fourth example, two exciting 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, so that the controller mechanism becomes large and Since the signal changes from a sine wave to a rectangular wave when switching the excitation circuit, a detection error is likely to occur.
Therefore, there is a drawback that the positioning accuracy is lowered. It is an object of the present invention to provide a resolver that can be operated by one exciting circuit both when energized and when a power failure occurs, and in which the power consumption of the backup circuit can be significantly reduced.

[0004]

SUMMARY OF THE INVENTION The present invention provides a resolver having a rotor provided with a one-phase excitation coil and a stator provided with two-phase detection coils having different 90 ° phases, and a resolver of the excitation coil. In a backup method and apparatus for a resolver in which power is supplied to a backup area including an excitation circuit by a backup battery, the backup area is constantly supplied with electric power, and a pulse wave is generated by the excitation circuit to excite the excitation coil. By holding the detection signal by a sample-hold circuit that samples in synchronization with the excitation circuit connected to the phase output detection coil, 90
° Two sine wave signals having different phases are obtained, and in particular, the backup battery is provided in parallel with a main DC power source for applying a DC voltage to the backup area. Further, a comparator is connected to the sample hold circuit, and the output of the comparator is counted and stored by the rotation amount storage circuit. Also,
A multi-phase exciting pulse is generated by the exciting circuit, and the exciting coils of the plurality of resolvers are excited by exciting pulses having different phases.

[0005]

[Function] Since the exciting coil of the resolver in the backup area is excited by the pulse wave by the exciting circuit, the power consumption is much smaller than that in the case of exciting by a normal sine wave, and the life of the backup battery is remarkably extended. You can Also, the pulse wave excitation frequency is changed according to the speed of the rotor of the resolver, and the detection signal is held by the sample hold circuit synchronized with the excitation circuit. Waves are obtained. Further, when exciting a plurality of resolvers, multi-phase pulse excitation is performed by the excitation circuit, and each exciting coil extracts and excites pulses having different phases, so that the voltage fluctuation of the backup battery can be reduced. The life can be extended.

[0006]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention.
Is a rotor fixed to the detected rotary shaft and provided with a one-phase exciting coil 11 and a two-phase detecting coil 1 having a 90 ° phase difference.
And a stator provided with 2a and 12b. As shown in FIG. 2A, the exciting coil 11 is pulse-excited by the exciting circuit 2 that generates the exciting pulse V _i at a predetermined timing. A sample hold circuit 3 for outputting 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 makes n rotations, As shown in FIG. 2B, sinusoidal signals V _0a and V _0b having the same mechanical angle 2π and n peaks and different phases of 90 ° from the signal after synchronous rectification are obtained. A comparator 4 is connected to the sample and hold circuit 3, and sinusoidal signals V _0a and V _0b . 2A corresponding to the rectangular wave position as shown in FIG. 2C, and outputs the A and B phase signals V _a and V _b 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 and the rotation angle θ is output. The rotation amount signal N of the rotation amount storage circuit 5 and the rotation angle θ which is the output of the R / D converter 6 are input to the controller 7, and the absolute value signal of the resolver 1 is obtained. ± 5V or ± 12 for R / D converter 6 and controller 7
The + side of the main DC power source 8 for applying a DC voltage of V is connected to the connection line 81.
, And the negative side is connected by a connecting line 82.
In addition, a backup area A including an excitation circuit 2, a sample hold circuit 3, a comparator 4, and a rotation amount storage circuit 5.
The main DC power source 8 is connected to the + side by the connection line 84 via the diode 83, and is connected to the − side by the connection line 86 via the diode 85 to supply electric power.
A backup battery 9 is provided in parallel with the main DC power source 8, the + side of the backup battery 9 is connected to the connection line 84 via the diode 91, and the − side is connected to the connection line 8 via the diode 92.
It is connected to 6. 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 hold circuit 3, the comparator 4, and the rotation amount storage circuit 5 by the main DC power supply 8, but a power failure occurs. When the main DC power supply 8 is shut down or the voltage drops, a backup battery 8 applies a DC voltage to the backup area A for backup.

Here, the life of the backup battery 8 for the backup area A is almost determined by the power consumption of the exciting circuit 2. However, in this case, since the excitation circuit 2 is excited by the pulse wave, the power consumption is much smaller than that of the conventional sinusoidal 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 5% duty with pulse wave excitation, the voltage and current waveforms are as shown in FIG. 6B. When the excitation voltage is 6V and the detection voltage is 1V, the detection current for sine wave excitation is 20m.
A, the power consumption is 252 mW, whereas the detected current of pulse wave excitation is 5 mA, the power consumption is 4.5 mW,
The power consumption of pulse wave excitation was about 1/50 of that of sinusoidal wave excitation. Therefore, by exciting the exciting circuit with a pulse wave, the life of the backup battery can be remarkably extended. Further, as shown in FIG. 4, when a plurality of resolvers 1 are backed up by one backup battery 8, a multiphase pulse excitation is performed by using a multiphase pulse generator for the excitation circuit 2. Since each exciting coil 11 extracts and excites pulses having different phases, the voltage fluctuation of the power source can be suppressed to a small value, and the life of the backup battery 8 used as the power source can be extended.

[0008]

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

[Brief description of drawings]

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

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

FIG. 3 is a comparative explanatory diagram of sinusoidal 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

Claims (1)

Claims: 1. A rotor provided with a one-phase exciting coil and a rotor.
In a backup method of a resolver in which a backup battery is provided with a backup area including a resolver having a stator provided with two-phase detection coils having different phases and an exciting circuit of the exciting coil, a backup area is provided in the backup area. Power is constantly supplied, a pulse wave is generated by the excitation circuit to excite the excitation coil, and a detection signal is held by a sample hold circuit that samples in synchronization with the excitation circuit connected to the two-phase output detection coil. Thus, a backup method for the absolute value resolver is characterized in that two sine wave signals having different 90 ° phases are obtained. 2. The backup method for an absolute value resolver according to claim 1, wherein a comparator is connected to the sample hold circuit, and the output of the comparator is counted and stored by a rotation amount storage circuit. 3. The backup of the absolute value resolver according to claim 1, wherein a multiphase excitation pulse is generated by the excitation circuit, and each of the excitation coils of the plurality of resolvers is excited by the excitation pulse having a different phase. Method. 4. A rotor provided with a one-phase exciting coil and 90.
In a resolver backup device including a resolver having a stator provided with two-phase detection coils having different phases and a backup battery for backing up a backup area including an exciting circuit of the exciting coil, a one-phase pulse wave Connected to the two-phase detection coil for generating the signal, sampling in synchronization with the excitation circuit, holding the detection signal of the detection coil, and outputting two sine wave signals having 90 ° different phases. And a sample and hold circuit for performing the absolute value resolver backup device. 5. The absolute value resolver backup device according to claim 4, wherein the backup battery is provided in parallel with a main DC power source for applying a DC voltage to the backup region.