JPS62144021A - Resolver detection apparatus - Google Patents

Abstract

PURPOSE:To obtain a highly accurate electromotor control system by reducing position and speed ripples, by modulating a comparing level by angle of rotation at the time of the shaping of a resolver detection signal. CONSTITUTION:Signals Valpha, Vbeta having 90 deg. phase difference are supplied to a resolver 2 and a compensation circuit 5 from an exciting circuit 1 and the signal Valpha is further sent to a wave from shaping circuit 4. The angle-of-rotation signal detected by the resolver 2 is sent to a wave form shaping circuit 3 and the compensation circuit 5. In the circuit 5, each exciting signal is introduced into a phase shift adjusting part 8 to form predetermined voltage with respect to amplitude, frequency and a phase and said voltage is multiplied by the angle- of-rotation signal in an analogue multiplier 9 and voltage of a predetermined phase is obtained through LPF (filter) 10, a gain adjusting part 11 and an offset adjusting part 12 to be supplied to the comparator of the shaping circuit 3. A comparing level is modulated by the angle-of-rotation signal in the circuit 3 to perform the shaping of a wave form and an output signal Ptheta is converted to a speed signal through a F/V converter circuit 6 and sent to a position operation part 7. Then, by counting from the rising of the output signal of circuit 4 to the rising of the signal Ptheta, a position signal is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resolver detection device in an electric motor control system.

[Conventional technology]

A resolver is essentially a rotation angle detector, and the excitation signal Y
] and the phase difference between the detection signal indicates the rotation angle.

Generally, the rotation angle and speed are detected after the excitation signal and the detection signal are shaped using a 21 inverter or the like.

FIG. 6 is a time chart of voltage waveforms representing this aspect.

Vo is an excitation voltage, Vo is a detection voltage, and P, , Pθ are waveforms each shaped by a comparator.

Furthermore, C and C are at a comparator level, and this hysteresis prevents the generation of erroneous signals.

From the waveform P(x, P, the rotation angle at the time point P.
360 can be obtained. However, the king is the period of the excitation voltage.

Waveform P is used for speed detection. Focusing on the frequency of , waveform Pθ is
/V (frequency → voltage) conversion method and time points P and P
There is a method of determining the range from the time change rate of the rotation angle between 0 and 0.

[Problem that the invention seeks to solve]

However, due to the precision of the machined surface of the resolver body, such as the shape of the iron core, 4:T ship, winding, etc., this phase difference is modulated by the rotation angle, and contains ripples at the actual rotation angle. become. This ripple has a large frequency component that is the same as the rotation angle.

Therefore, in the conventional position and speed detection means, position and speed ripples having the same frequency component as the rotation angle occur, which is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a resolver detection device that overcomes the drawbacks of conventional means, reduces position and velocity ripples, and constitutes a highly accurate motor control system.

[Means for solving problems]

The present invention is a means for modulating the comparator level of a comparator with a rotation angle using a compensation circuit when shaping a resolver detection signal.

[For n'] Therefore, since the comparator level is modulated by the rotation angle, the resolver detection device has reduced position and velocity ripples of the same frequency component as the rotation angle.

(Embodiment) FIG. 1 shows a block diagram showing a circuit configuration in an embodiment of the present invention.

1 is a two-phase excitation signal V to the resolver 2 with a phase difference of 90 degrees (electrical angle). , Vβ, and 3 and 4 are shaping circuits.

5 is a compensation circuit according to the present invention which outputs a signal modulated according to the rotation angle.

6 is a rectangular wave P obtained by shaping the detection signal with an F/V conversion circuit. A signal corresponding to the frequency of 1 is output, that is, a signal indicating the speed.

7 is a rectangular wave P obtained by shaping the excitation voltage V. It counts from the rising edge of the rectangular wave P to the rising edge of the rectangular wave P, calculates the position, and outputs a position signal.

FIG. 2 is a plotter diagram showing the circuit configuration of the compensation circuit 5.

8 is an excitation signal V at a phase shift adjustment section. - K CO3 (1) t, V, 3 = 1 sin (
IZ). From t, a signal of 2CO5 (ω.t+φ) is output to C 2 =.

In addition, K1 and K2 are amplitudes, ωc=2πf, r is excitation frequency, t is time, and φ is the phase adjusted here.

9 is an analog multiplier, and the resolver detection signal Vθ = 3 sin (ωct 10) and the signal V1 are multiplied by 1,
After removing high frequency components with a filter 10, passing through a gain adjustment section 11 and an offset adjustment section 12, the output signal of the compensation circuit 5 becomes ■ = △ + A25in (0 + φ). Here, K3 is the amplitude, and θ is the resolver. The detection phases A and A2 are constants.

The signal obtained by this compensation circuit 5 is applied to a shaping circuit 3 using a comparator 13 as shown in FIG.

J3.18 is an output end, and 20 to 22 are resistors.

FIG. 4 shows the detection signal 14. when the resolver 2 is rotating at a constant speed. It is a waveform diagram showing a comparator level 15 and position ripples 16 and 17.

Reference numeral 16 indicates a ripple at a position that occurs when a constant comparator level CL is used when the detection signal includes the ripple.

Reference numeral 17 indicates a positional ripple that occurs when the sampled level 15 modulated by the compensation method of the present invention is applied when the detection signal does not include the ripple.

On the other hand, when the detection signal includes ripples, by using the comparator level 15 appropriately modulated by the rotation angle by the compensation of the present invention, it is possible to reduce the position ripple of the same frequency component as the rotation angle.

After performing similar compensation in speed detection, F/V
By performing the conversion, it is possible to reduce the velocity ripple of the same frequency component as the rotation angle.

Therefore, the shaping circuit 3 in FIG. 3 functions as an F/V converter.
This is a means for using only the rising edge of the rectangular waveform Pθ.

When using a decoal F/V that uses both the rising and falling edges of the rectangular waveform Pθ as another means of the shaping circuit 3, the modulated comparator level must be symmetrical in positive and negative, but an example of a circuit in that case is shown in Figure 5,
19 is an analog multiplier t1, and 23 to 25 are resistors.

〔Effect of the invention〕

Thus, according to the present invention, in the resolver and the 16 motor control system, by modulating the comparator level of the comparator applied when shaping the waveform of the detection signal according to the rotation angle, the speed and the frequency component of the same frequency component as the rotation angle are modulated. A resolver detection device capable of reducing positional ripples and configuring a highly accurate electric b1 control system has been realized, which will greatly contribute to the field concerned.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of the present invention, FIG. 2 is a detailed diagram of a compensation circuit, and FIG. 3 is a block diagram showing a circuit configuration of an embodiment of the present invention. Figure 5 is a connection diagram of the shaping circuit, Figure 4 (a) is a diagram of the relationship between the detection signal and the comparator level, and (b) is the relationship between ripples in position when the comparator level is constant and modulated according to rotation and angle. FIG. 6 is an explanatory diagram of the resolver detection signal. 1... Excitation circuit 2... Resolver 3.4... Shaping circuit 5... Compensation circuit 6... F/V conversion circuit 7... ...Position calculation section 8...Phase shift adjustment section 9.19...Analog multiplier 10...Filter 11...Gain adjustment section 12... Offset J1 adjustment section 13...Comparator. ' Fig. 1 Fig. 2 Fig. 13 Comparator Fig. 3 (1" (α) Fig. 4 Fig. 5

Claims (1)

[Scope of Claims] 1. In a motor control system that uses a resolver as a position and speed detector, in a device that shapes a resolver detection signal with a comparator and generates a position and speed signal from the shaped waveform, the comparator is used when shaping the detection signal. A resolver detection device characterized by comprising means for modulating the comparator level with the rotation angle of the resolver. 2. From the resolver excitation voltage V_α=K_1cosω_ct V_β=K_1sinω_ct, the adjusted signal V_1=K2cos(ω_ct+φ) where K_1, K_2 are amplitudes, ω_c=2πf, f is excitation frequency, t is time, and φ is adjusted. a phase shift adjustment unit that outputs the phase, and a resolver detection signal V_θ=K_3sin(ω_ct+θ), where K_3 is the amplitude and θ is the detection phase; an analog multiplier that multiplies the adjusted signal V_1; A filter that introduces the multiplier output V_2 and removes its high frequency components; A gain adjustment unit that inputs the filter output V_3 and adjusts the gain of this signal V_3; and a signal V_5 = A_1 + A_2 (sin θ + φ) from the gain adjustment unit output V_4. . The resolver detection device according to item 1.