JP2606999B2 - Resolver signal connection device - 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 which is an analog sensor for detecting a rotation angle, and more particularly to a connecting device for connecting signals from a plurality of resolvers to a resolver digital converter (RDC). It is about.

[0002]

2. Description of the Related Art In general, a resolver is used as a sensor for detecting a rotation angle in an analog manner. This resolver is an inductive element similar to a synchro. Both a rotor and a stator have two sets of orthogonal windings, and are used for a detection system of a servo mechanism. Since the signal from the resolver is analog, a resolver digital converter (RDC) for converting the signal into a digital signal is prepared.

Conventionally, the digital converter and the resolver have been used in a one-to-one correspondence. However, from the viewpoint of cost, a configuration in which one converter and a plurality of resolvers are connected and used has been proposed.

As shown in FIG. 3, sine and cosine signals from two resolvers 50 are connected to a digital converter 52 via analog switches 51, respectively. When the analog switch 51 is switched, a desired resolver signal is obtained. In the resolver digital converter 52,
As shown in FIG. 4, a compensator 53, a voltage controlled oscillator 54,
A servo loop including a counter 55 and a multiplying D / A converter 56 is formed. The output data latch 57 for reading the value is connected to the counter 55.

A digital angle φ is set inside the converter 52, and a sine and cosine signal corresponding to the digital angle φ is generated by a data conversion ROM 58. Resolver 50
Are multiplied by the multiplication type A / D converter 56 and converted into an AC error signal sin (θ−φ). The compensator 53 generates a deviation signal that makes the AC error signal sin (θ−φ) zero, and sends the deviation signal to the voltage controlled oscillator 54. This deviation signal is converted into a pulse by the voltage controlled oscillator 54, and the counter 55 is clocked up when the deviation signal is positive and clocked down when the deviation signal is negative. The value of this counter 55 corresponds to the digital angle φ, the servo loop is balanced, and the AC error signal
When sin (θ−φ) converges to zero, the value of the counter 55 is read from the output data latch 57, and the value of the angle signal θ can be detected.

[0006]

However, when switching signals from two or more resolvers, there is a case where the angle between one resolver and the other resolver is 180 °. At this time, the first resolver AC error signal sin (θ−
When φ) is zero and the servo loop is balanced, 18
0 ° phase shifted AC error signal sin ((θ + 180 °)
−φ) or sin ((θ−180 °) −φ) also becomes zero.
That is, the servo loop is balanced despite the phase difference of 180 °. Therefore, the digital angle φ
There is a problem that the value of is not switched and an erroneous reading is performed.

Accordingly, the present invention has been made in view of the problems existing in such conventional techniques, and an object thereof is to provide a single digital converter for a resolver while maintaining data reliability. It is an object of the present invention to provide a device for connecting a plurality of resolvers with a device.

[0008]

In order to achieve the above object, in the present invention, a plurality of resolvers are connected to two analog switches for a sine signal and a cosine signal, and the switches from the plurality of resolvers are switched by switching the switches. A gist of the present invention is that in a resolver signal connection device for selecting a predetermined signal from the signals and inputting the signal to the resolver digital converter, delay means for delaying switching of the analog switch to one of the switching positions is provided. I have.

[0009]

According to the above arrangement, of the plurality of resolvers, the first resolver is provided.
Sine and cosine signals of the resolver are sent to the resolver digital converter via two analog switches,
It is converted to a digital signal. Next, when reading the signal of the second resolver, the analog switch for the sine signal is first switched, and the sine signal of the second resolver and the cosine signal of the first resolver are sent to the digital converter. Then, after a certain delay time, the analog switch for the cosine signal is switched, and the digital converter has the second switch.
Sine and cosine signals of the resolver are sent.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in two resolver signal connection devices will be described below with reference to FIGS.

As shown in FIG. 1, two resolvers 1, 2
Has sine signal lines 3 and 5 and cosine signal lines 4 and 6, respectively. The sine signal line 3 from the first resolver 1 is connected to a first input terminal 9 of a sine signal analog switch 7. The cosine signal line 4 of the first resolver 1 is connected to a first input terminal 13 of the analog switch 8 for cosine. The sine signal line 5 of the second resolver 2 is connected to the second input terminal 10 of the analog switch 7 for sine, and the cosine signal line 6 is connected to the analog switch 8 for cosine.
Are connected to the second input terminal 14 of the first embodiment.

An output terminal 12 of the analog switch 7 for sine signal is connected to a sine signal input terminal 18 of a digital converter 17 for a resolver, and an output terminal 16 of the analog switch 8 for cosine signal is connected to a cosine signal input terminal 19. I have. The channel select terminal 11, which is a switching input terminal of the analog switch 7 for a sine signal, is directly connected to the switching terminal 22. On the other hand, the channel select terminal 15 of the cosine signal analog switch 8 is connected to the switching terminal 22 via a delay circuit which is a delay means including a resistor 20 and a capacitor 21.

The operation when the two resolver signals have a phase difference of 180 ° in the resolver signal connection device configured as described above will be described. When the switching terminal 22 is held at a low level, the first input terminals 9 and 13 are selected for the two analog switches 7 and 8, and the first resolver 1 is selected.
Are input to the resolver digital converter 17. At this time, the resolver signal 23 input to the converter 17 is a signal shown in FIG. Converter 17
In the servo loop, the AC error signal sin (θ ₁ −φ)
Becomes zero, and the angle signal θ ₁ is read.

Subsequently, when a high level is applied to the switching terminal 22, the channel select terminal 11 of the analog switch 7 for sine signals is set to a high level, and the second input terminal 10 is selected. On the other hand, the channel select terminal 15 of the cosine signal analog switch 8 is held at a low level for a predetermined time due to the action of the delay circuit, during which the first input terminal 13 is kept selected. That is, the signal input to the converter 17 is a composite signal 25 of the sine signal of the second resolver 2 and the cosine signal of the first resolver 1 and becomes a signal shown in FIG.

In FIG. 2C, the composite signal 25 has a phase difference of 90 ° from the first resolver signal 23, so that the servo loop of the digital converter 17 starts oscillating without being balanced and then rebalanced. AC error signal sin ((θ ₁
+ 90 °) -φ) becomes zero. In this case, the angle signal is not read.

After a predetermined time, the channel select terminal 15 of the cosine signal analog switch 8 shifts to the high level, and the second input terminal 14 is selected. At this time, the resolver signal 24 input to the converter 17 becomes a signal shown in FIG. This signal 24 has a phase difference of 90 ° from the composite signal 25 of FIG.
The servo loop of No. 7 starts oscillating without being balanced, and then balances again, and the AC error signal sin (θ ₂ −φ) becomes zero. That is, the angle signal θ ₂ is read.

As described above, the two resolver signals 23,
Even when the signal is switched when the phase shifter 24 has a phase difference of 180 °, the two resolvers 1 and 2 are once operated by the delay circuit.
Since the composite signal 25 is generated, the servo loop is not balanced and erroneous reading is not performed.

The present invention is not limited to the configuration of the above-described embodiment. For example, the channel selection of the analog switch is performed by a microprocessor, and a delay is generated by a timer to generate a composite signal. The configuration of each unit may be arbitrarily changed and embodied without departing from the spirit.

[0019]

As described above, according to the present invention, by providing a delay circuit at one of the switching signal input terminals of the analog switch, signals from a plurality of resolvers can be digitally converted by one resolver digital converter. The conversion can be performed, so that an accurate value can be obtained even if there is a difference of 180 ° between the signals of both resolvers.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of a resolver signal connection device embodying the present invention.

FIG. 2A is an explanatory diagram illustrating a resolver signal of a first resolver. (B) It is explanatory drawing which shows the resolver signal of a 2nd resolver. (C) It is explanatory drawing which shows the synthetic | combination signal in the middle of switching of a 1st resolver and a 2nd resolver.

FIG. 3 is a circuit diagram showing a conventional resolver signal connection device.

FIG. 4 is a block diagram showing functions of a conventional resolver digital converter when a resolver signal is switched.

[Explanation of symbols]

1 first resolver, 2 second resolver, 7 analog switch for sine signal, 8 analog switch for cosine signal, 17 digital converter, 20 resistor, 21 capacitor.

Claims (1)

(57) [Claims] 1. A plurality of resolvers are connected to two analog switches for a sine signal and a cosine signal, and a predetermined signal is selected from the signals from the plurality of resolvers by switching the switches to provide a digital signal for the resolver. A resolver signal connection device for inputting, wherein a delay means for delaying switching of one of the analog switches to one of the switching positions is provided.