JP2008298745A - Rotation detection device using resolver - Google Patents

Abstract

A rotation detection device using a conventional resolver uses a R / D converter to obtain a rotation angle, and detects a rotation direction and a rotation speed from the rotation angle.
A rotation detection device using a resolver according to the present invention includes a sin signal limit value pulse 10c and a cos signal limit value pulse 11c indicating timings at which a sin signal 1b and a cos signal 1c become limit values, and the sin signal 1b. The quadrant detection unit 15 detects the quadrant of the input angle based on the polarity determination pulse 12c for determining the polarity of the limit value of the cos signal 1c, and the quadrant detection result and the number of pulses of the limit value pulses 10c and 11c. Based on the above, the rotation detection unit 16 detects the rotation speed and the rotation direction.
[Selection] Figure 1

Description

  The present invention relates to a rotation detection device using a resolver, and in particular, the number of revolutions of a resolver shaft based on a sin signal limit value pulse, the number of pulses of the cos signal limit value pulse, and a quadrant of an input angle detected by a quadrant detection unit. Further, the present invention relates to a novel improvement that can eliminate the expensive R / D converter by detecting the rotation direction and reduce the component cost.

  In general, a resolver is excellent in environmental resistance, and is useful for an apparatus having severe environmental conditions. As a rotation detection device using this type of resolver that has been used in the past, for example, a device shown in Patent Document 1 or the like is used, and this type of device is generally as shown in FIG. It is configured. FIG. 4 is a block diagram showing a rotation detection device using a conventional resolver. Although not shown, the resolver 1 is provided with a resolver shaft, an excitation winding, a sin signal output winding, and a cos signal output winding as is well known, and the resolver shaft is connected to an external device that is a rotation detection target. The excitation winding is connected and excited by the reference signal 1a. The sin signal output winding and the cos signal output winding output a sin signal 1b and a cos signal 1c that change in accordance with the input angle of the resolver shaft and have a phase difference of 90 ° from each other.

  An R / D converter 3 is connected to the resolver 1 via an input amplifier 2, and the sin signal 1 b and the cos signal 1 c are amplified by the input amplifier 2 and then angle data is output by the R / D converter 3. Converted to 3a. The R / D converter 3 is connected to a processing unit 4 composed of a CPU or the like. The processing unit 4 detects the rotational speed and rotational direction of the resolver shaft based on the increase / decrease of the angle data 3a.

JP-A-9-68439

  Generally, the R / D converter 3 is an expensive part due to its complicated configuration. In the rotation detection device using the conventional resolver as described above, since the expensive R / D converter 3 is used, the entire device is also expensive.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a rotation detection device using a resolver in which the expensive R / D converter 3 can be omitted and the component cost can be reduced. That is.

The rotation detection device using the resolver according to the present invention includes an excitation winding excited by a reference signal, a sin signal output winding and cos for outputting a sin signal and a cos signal that change according to an input angle to the resolver shaft. A rotation detection apparatus using a resolver including a signal output winding, wherein a sin signal limit value pulse indicating a timing at which the sin signal becomes a limit value is generated by converting the sin signal into a digital signal. A signal A / D converter, a cos signal A / D converter that generates a cos signal limit value pulse indicating a timing at which the cos signal becomes a limit value by converting the cos signal into a digital signal, and the reference A polarity determination pulse for determining the polarities of the extreme values of the sin and cos signals by converting the signal into a digital signal. A reference signal A / D conversion unit for generating a quadrant of the input angle based on the sin signal limit value pulse, the cos signal limit value pulse, and the polarity determination pulse, and the sin signal A rotation detector for counting the number of pulses of the limit value pulse and the cos signal limit value pulse, and detecting the number of rotations and the direction of rotation of the resolver shaft based on the number of pulses and the quadrant detection result of the input angle; It is the composition provided.
The sin signal A / D conversion unit and the cos signal A / D conversion unit generate the sin signal limit value pulse and the cos signal limit value pulse by using a common first reference voltage, and a positive limit. The sin signal limit value pulse corresponding to the value and the negative limit value is generated at a timing shifted by a half cycle of the sin signal, and the cos signal limit value corresponding to the positive limit value and the negative limit value. The pulse is generated at a timing shifted by a half cycle of the cos signal and at a timing shifted by 90 ° from the sin signal limit value pulse.

According to the rotation detection device using the resolver of the present invention, the rotation detection unit counts the number of pulses of the sin signal limit value pulse and the cos signal limit value pulse, and detects the quadrant of the number of pulses and the input angle. Since the rotational speed and direction of the resolver shaft are detected based on the result, the expensive R / D converter 3 can be omitted, and the component cost can be reduced. That is, the rotation detection device can be provided at low cost. That is, the present invention is particularly effective for a rotation detection target that does not need to detect a fine rotation angle during one rotation and only needs to detect the rotation speed and the rotation direction.
The sin signal A / D conversion unit and the cos signal A / D conversion unit may use the common first reference voltage and the sin signal limit value pulse corresponding to the positive limit value and the negative limit value, and Since the cos signal limit value pulse is generated, the circuit configuration can be simplified by reducing the number of reference voltages, and the component cost can be further reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing a rotation detection device using a resolver according to Embodiment 1 of the present invention. The same or equivalent parts as those in the conventional apparatus will be described using the same reference numerals. Although not shown, the resolver 1 is provided with a resolver shaft, an excitation winding, a sin signal output winding, and a cos signal output winding as is well known, and the resolver shaft is connected to an external device that is a rotation detection target. The excitation windings are connected and excited by a reference signal (REF signal) 1a. The sin signal output winding and the cos signal output winding output a sin signal 1b and a cos signal 1c that change in accordance with the input angle of the resolver shaft and have a phase difference of 90 ° from each other.

  The resolver 1 is connected with a sin signal A / D conversion unit 10 and a cos signal A / D conversion unit 11, and these A / D conversion units 10, 11 include input amplifiers 10 a, 11 a and comparators 10 b, 11 b. It is composed of The input amplifiers 10a and 11a amplify the sin signal 1b and the cos signal 1c, and the comparators 10b and 11b convert the signals 1b and 1c amplified by the input amplifiers 10a and 11a to 2 based on the common first reference voltage 13, respectively. Convert to digital signal of value. As will be described later with reference to the drawings, the digital signals output from the comparators 10b and 11b are a sin signal limit value pulse 10c and a cos signal limit value pulse 11c indicating the timing at which the sin signal 1b and the cos signal 1c become limit values. .

  A reference signal A / D converter 12 including an input amplifier 12a and a comparator 12b is connected to a signal source of the reference signal 1a. The input amplifier 12a amplifies the reference signal 1a, and the comparator 12b includes an input amplifier 12a. The reference signal 1a amplified in step (b) is converted into a binary digital signal based on the second reference voltage. As will be described later with reference to the drawings, the digital signal output from the comparator 12b is a polarity determination pulse 12c for determining the polarities of the extreme values of the sin signal 1b and the cos signal 1c.

  A quadrant detector 15 and a rotation detector 16 are connected to each of the A / D converters 10 to 12, and the quadrant detector 15 is based on the limit value pulses 10c and 11c and the polarity determination pulse 12c. The rotation detection unit 16 counts the number of pulses of the limit value pulses 10c and 11c, and the resolver based on the number of pulses and the quadrant detection result of the input angle. The rotational speed and rotational direction of the shaft are detected, and the rotational speed signal 16a and the rotational direction signal 16b are output to the outside.

  Hereinafter, the signal processing performed by the rotation detection device will be described more specifically. FIG. 2 is an explanatory diagram showing the relationship between the sin signal 1b and the cos signal 1c of FIG. 1 and the input angle. As shown in the figure, the sin signal 1b and the cos signal 1c are signals that change in accordance with the input angle, and have a phase difference of 90 ° from each other. Therefore, the number of revolutions of the resolver shaft can be detected by counting the timing at which the sin signal 1b and the cos signal 1c reach the limit values. However, it is impossible to detect the rotational direction, that is, the direction of 1 → 2 → 3 → 4 or the direction of 4 → 3 → 2 → 1 in the figure only by counting the timing at which the limit value is reached. For this reason, in the apparatus of this embodiment, when the sin signal 1b and the cos signal 1c reach the limit value, it is determined whether the limit value is a positive limit value or a negative limit value, and the rotation direction At the same time, the rotational speed is detected.

  Next, FIG. 3 is an explanatory diagram showing a method for detecting the number of rotations and the direction of rotation performed by the rotation detection device using the resolver 1 of FIG. In FIG. 2, the sin signal 1b and the cos signal 1c are shown in relation to the input angle, but in FIG. 3, the signals 1b and 1c are shown in relation to time. As is well known, when the sin signal 1b is shown on the time axis, the signal when the input angle is 0 ° to 180 ° and the signal when the input angle is 180 ° to 360 ° are signals that are 180 ° out of phase. In FIG. 3, a sin signal 1b indicated by a solid line is a signal when the input angle is 90 ° (positive limit value), and a broken line indicates a signal when the input angle is 270 ° (negative limit value). Signal.

  A sin signal limit value pulse 10c is generated from the sin signal A / D converter 10 at a timing shifted by a half cycle of the sin signal 1b depending on whether the input angle is 90 ° or 270 °.

  In this embodiment, the second reference voltage 14 for generating the polarity determination pulse 12c is set to zero. That is, the polarity determination pulse 12c indicates whether the output of the reference signal 1a is a positive period or a negative period. The quadrant detection unit 15 detects whether the limit value of the sin signal 1b is a positive limit value or a negative limit value based on the combination of the polarity determination pulse 12c and the sin signal limit value pulse 10c. .

  Similarly, the cos signal A / D converter 11 generates a cos signal limit value pulse 11c at a timing shifted by a half cycle of the cos signal 1c depending on whether the input angle is 0 ° or 180 °. . The generation timing of the cos signal limit value pulse 11c is 90 ° out of phase with the generation timing of the sin signal limit value pulse 10c. The quadrant detection unit 15 detects whether the limit value of the cos signal 1c is a positive limit value or a negative limit value based on the combination of the polarity determination pulse 12c and the cos signal limit value pulse 11c. The quadrant of the input angle is detected from the limit value detection results of the signals 1b and 1c.

  Here, when the phase of the reference signal 1a coincides with the phase of the sin signal 1b and the second reference voltage 14 is 0, the cos signal limit value pulse 11c rises and falls on the polarity determination pulse 12c. Since it straddles, the limit value of the cos signal 1c cannot be determined. However, in general, a phase shift occurs between the reference signal 1a and the sin signal 1b due to excitation and signal output from the resolver 1, and this phase shift can be used. Note that the polarity determination pulse 12c may be generated after the phase of the reference signal 1a is positively shifted in the reference signal A / D converter 12. In addition, the limit value of the cos signal 1c can be determined even if the second reference voltage 14 is set to a positive or negative predetermined value without setting it to zero.

It is a block diagram which shows the rotation detection apparatus using the resolver by Embodiment 1 of this invention. It is explanatory drawing which shows the relationship between the sin signal and cos signal of FIG. 1, and an input angle. It is explanatory drawing which shows the detection method of the rotation speed and rotation direction which are performed with the rotation detection apparatus using the resolver of FIG. It is a block diagram which shows the rotation detection apparatus using the conventional resolver.

Explanation of symbols

1 resolver 1a reference signal 1b sin signal 1c cos signal 10 sin signal A / D conversion unit 10c sin signal limit value pulse 11 cos signal A / D conversion unit 11c cos signal limit value pulse 12 reference signal A / D conversion unit 12c polarity determination Pulse 13 First reference voltage 15 Quadrant detection unit 16 Rotation detection unit

Claims (2)

An excitation winding excited by a reference signal (1a), a sin signal output winding and a cos signal output winding for outputting a sin signal (1b) and a cos signal (1c) that change according to the input angle of the resolver shaft; A rotation detection device using a resolver (1) including:
By converting the sin signal (1b) into a digital signal, a sin signal A / D conversion unit (10) that generates a sin signal limit value pulse (10c) indicating a timing at which the sin signal (1b) becomes the limit value. When,
By converting the cos signal (1c) into a digital signal, a cos signal A / D converter (11) that generates a cos signal limit value pulse (11c) indicating a timing at which the cos signal (1c) becomes the limit value. When,
A reference signal A that generates a polarity determination pulse (12c) for determining the polarities of the extreme values of the sin signal (1b) and the cos signal (1c) by converting the reference signal (1a) into a digital signal. / D conversion unit (12),
A quadrant detection unit (15) for detecting a quadrant of the input angle based on the sin signal limit value pulse (10c), the cos signal limit value pulse (11c), and the polarity determination pulse (12c);
The number of pulses of the sin signal limit value pulse (10c) and the cos signal limit value pulse (11c) is counted, and the number of rotations and rotation of the resolver shaft are determined based on the number of pulses and the quadrant detection result of the input angle. A rotation detection device using a resolver, comprising: a rotation detection unit (16) for detecting a direction. The sin signal A / D conversion unit (10) and the cos signal A / D conversion unit (11) use the common first reference voltage (13) and the sin signal limit value pulse (10c) and the cos signal. Generating an extreme value pulse (11c);
The sin signal limit value pulse (10c) corresponding to the positive limit value and the negative limit value is respectively generated at a timing shifted by a half cycle of the sin signal (1b), and the positive limit value and the negative limit value are generated. The cos signal limit value pulse (11c) corresponding to the above is generated at a timing that is shifted by a half cycle of the cos signal (1c) and at a timing that is 90 ° out of phase with the sin signal limit value pulse (10c). The rotation detection apparatus using the resolver according to claim 1.

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