JPH0592642U - Rotational position detector - Google Patents

Abstract

(57) [Summary] [Purpose] Accurate data correction can be easily performed by making the input / output characteristics of the resolver correspond one-to-one. [Structure] 2 with different 90 ° phases for exciting resolver 4
The triangular waves S1 and S2 are used as the phase excitation signals. Since the resolver output with respect to the mechanical angle corresponds to a smooth calibration curve with a one-to-one correspondence, accurate data correction can be easily performed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotational position detector equipped with a phase-detecting resolver that excites a two-phase signal and outputs a one-phase signal.

[0002]

[Prior Art]

 The form (circuit configuration) of the resolver used in the rotational position detection device is a phase detection type that is excited by a two-phase signal to obtain a one-phase output signal, and a voltage detection type that is excited by a one-phase signal to obtain a two-phase output signal. It is roughly divided into types. Of these, the former phase detection type is advantageous over the latter voltage detection type in that the circuit configuration is simple (compared to the digital part) and the cost is reduced.

FIG. 5 is a block diagram showing a conventional rotational position detecting device using a phase detection type resolver. Reference numeral 1 is a clock signal oscillator, and 2 is a sine wave that generates a Sin wave (sine wave) signal as shown in FIG. A wave oscillator, 3 is a phase shifter for shifting a sine wave by 90 ° into a Cos wave (cosine wave) signal as shown in FIG. 6, and 4 is a two-phase signal of a sine wave and a cosine wave having different 90 ° phases. A resolver 5 that is excited to output a one-phase signal is a phase difference at a zero-cross point between a sine wave that is a reference signal to which each output signal of the clock signal oscillator 1, the sine wave oscillator 2 and the resolver 4 is input and the resolver output signal. Is a phase detector that detects the phase, and 6 is a counter that counts and outputs the phase from the output of the phase detector 5.

By the way, in the rotational position detecting device having the configuration shown in FIG. 5, the output waveform is distorted when there is an amplitude imbalance between the two phase signals exciting the resolver 4 or a phase difference of 90 °. .. FIG. 7 is a characteristic diagram showing this situation, and the maximum absolute phase error | ε | max during the rotation of the resolver is 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes, respectively. The relationship between the amplitude imbalance a (%) and the phase shift b (minute) is shown. The vertical axis represents the phase shift b (minutes). Such a drawback is that the distortion of the output waveform is a major cause of the measurement error in the detection principle that the rotational position is detected from the phase difference of the zero cross point between the reference signal (Sin wave) and the output signal. There is. Therefore, in the case of the phase detection type resolver, the symmetry of the excitation waveform is strictly required.

In order to satisfy such a requirement, the waveform data stored in the ROM 7 as one means for generating an excitation signal as shown in FIG. 8 is used after being D / A converted by the D / A converter 8. Is provided. FIG. 9 shows the excitation signal of the pseudo sine wave thus obtained. With such a configuration, there is no influence of unbalance such as temperature drift of the clock signal oscillator 1, so that the phase shift unlike the rotational position detecting device of the configuration of FIG. 5 does not occur.

[0006]

[Problems to be solved by the device]

 By the way, in the conventional rotational position detecting device, since the waveform of the signal for exciting the resolver is a pseudo sine wave that approximates a staircase, the output waveform also becomes a pseudo sine wave that approximates a staircase. Figure 10 shows this situation. The characteristics of (a) are for 64 divisions, the characteristics of (b) are for 128 divisions, the horizontal axis is the mechanical angle (degrees), and the vertical axis is the resolver. The output (degree) is shown. Since the output waveform is a pseudo sine wave in this way, the zero-cross points do not change smoothly and take a discrete value according to the number of divisions of the waveform data of the ROM 7. Since such input / output characteristics do not correspond one-to-one with such a quantization error, data correction using a calibration curve could not be performed.

The present invention has been made in consideration of the above problems, and provides a rotary position detecting device in which accurate data correction can be easily performed by making the input / output characteristics correspond one-to-one. It is intended to be provided.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an oscillator that generates two-phase excitation signals having different 90 ° phases, a resonator that receives the two-phase excitation signals and outputs a one-phase output signal, and A rotational position detecting device having a phase detector for detecting a phase difference between a one-phase output signal and a reference signal, wherein the two-phase excitation signal generated from the oscillator is a triangular wave. It is a thing.

[0009]

[Action]

 By using a triangular wave as a two-phase excitation signal that excites the resolver, the input / output characteristics of the resolver become a smooth calibration curve with a one-to-one correspondence, so that accurate data correction can be easily performed.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the rotational position detecting device of the present invention, 1 is a clock signal oscillator for generating a clock signal, 4 is a resolver, 5 is a phase detector, 6 is a counter, and FIG. 8 has the same function.

Reference numeral 9 denotes a 1/2 frequency divider that divides a clock signal generated from the clock signal oscillator 1 into a frequency of 1/2 and outputs the divided signal. A triangular wave oscillator 10 that outputs a triangular wave S1 such as 2 is an exclusive logic that inputs the outputs of the clock signal oscillator 1 and the 1/2 frequency divider 9 and outputs an H level only when both signals have different levels. A circuit, 12 is a triangular wave oscillator for inputting the output of the exclusive logic circuit 10 and outputting the triangular wave S2 as shown in FIG. 2 with a phase difference of 90 ° from the triangular wave S1, and the triangular wave oscillators 11 and 12 output 90. Two-phase triangular waves S1 and S2 having different phases are input to the resolver 4 as excitation signals.

FIG. 3 is a characteristic diagram showing the relationship between the mechanical angle (degree) on the horizontal axis and the resolver output (degree) on the vertical axis, which is obtained by the rotational position detecting apparatus of the present embodiment having the above-mentioned configuration. The input / output characteristics of are smooth calibration curves with a one-to-one correspondence. Therefore, with this calibration curve, the data can be corrected easily and accurately.

FIG. 4 shows that | ε | max (maximum absolute value of phase error during one revolution of the resolver) after data correction is 2.5 minutes, 5 minutes, 7.5 minutes, and 10 minutes, respectively. In the characteristic diagram showing the relationship between the amplitude imbalance a (%) and the phase shift b (minutes), the margin related to the amplitude imbalance a is increased by about 30% compared to the case of the sine wave excitation of FIG. It shows that you can do it.

As described above, according to this embodiment, since the triangular wave is used as the two-phase excitation signal for exciting the resolver, the input / output characteristics of the resolver can be made to correspond one-to-one. Therefore, accurate data correction can be easily performed. Moreover, since the triangular wave can be dealt with by a simpler generation means than the conventional sine wave, the circuit can be simplified and the cost can be reduced.

[0015]

[Effect of the device]

 As is clear from the above description, according to the present invention, the resolver is excited by the two-phase excitation signals of the triangular wave, so that the input / output characteristics of the resolver can be made to correspond one-to-one, and It is possible to easily correct various data.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a rotational position detecting device of the present invention.

FIG. 2 is a waveform diagram of a triangular wave used as an excitation signal in this embodiment.

FIG. 3 is a characteristic diagram showing a relationship between a mechanical angle and a resolver output in the present embodiment.

FIG. 4 is a characteristic diagram showing a relationship between an amplitude imbalance and a phase shift in the present embodiment.

FIG. 5 is a block diagram showing an example of a conventional rotational position detecting device.

6 is a waveform diagram of a sine wave and a cosine wave used as the excitation signal of FIG.

FIG. 7 is a characteristic diagram showing the relationship between the amplitude imbalance and the phase shift in FIG.

FIG. 8 is a block diagram showing another example of a conventional rotational position detecting device.

9 is a waveform diagram of a pseudo sine wave used as the excitation signal of FIG.

10 is a characteristic diagram showing the relationship between the mechanical angle and the resolver output of FIG.

[Explanation of symbols]

 1 Clock Signal Oscillator 4 Resolver 5 Phase Detector 6 Counter 9 1/2 Divider 10 Exclusive Logic Circuit 11, 12 Triangular Wave Oscillator

Claims (1)

[Scope of utility model registration request] 1. An oscillator for generating two-phase excitation signals having different 90 ° phases, a resolver for receiving the two-phase excitation signals and outputting a one-phase output signal, and the one-phase output signal and a reference signal. And a phase detector that detects the phase difference between the
A rotational position detecting device characterized in that a phase excitation signal is a triangular wave.