JPH03262971A - Speed and acceleration detecting device - Google Patents

Abstract

PURPOSE:To obtain a highly accurate speed signal which has a small ripple and small phase delay by outputting an A-phase and a B-phase sine wave which are 90 deg. out of phase with each other by a position detecting device and outputting the differentiated values of the A phase and B phase by two differentiators. CONSTITUTION:The A-phase sine wave and B-phase sine wave which are outputted by the position detecting device and 90 deg. out of phase with each other are expressed by I. Then the A-phase sine wave and B-phase sine wave are differentiated by the differentiators 1 and 2 to obtain expressions II. Then a multiplier 3 outputs the product K<2> (2piX/lambda)cos<2>(2piX/lambda) of the differentiated value of the A phase and the B phase and a multiplier 4 outputs the product -K<2>(2piX/lambda)sin<2>(2piX/lambda) of the differentiated value of the B phase and the A phase. Then a subtracter 5 outputs the difference between the outputs of the multipliers 3 and 4, i.e. (2pi/lambda)K<2>X, but (2pi/lambda)K<2> is a constant, so it is evident that the output of the subtracter 5 is a speed signal whose ripple and phase delay are extremely small over the entire band.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to speed and speed control devices used in industrial robot control devices.
This invention relates to an acceleration detection device.

BACKGROUND OF THE INVENTION In recent years, control of industrial robots has become more sophisticated, and demands for highly accurate positioning, trajectory control, force control, etc. are increasing. As a means of achieving this, the need for highly accurate speed/acceleration detection devices is increasing.

An example of the above-mentioned conventional speed/acceleration detection device will be described below with reference to the drawings.

FIG. 5 shows the configuration of a conventional speed/acceleration detection device. In Fig. 5, 27.28 is a comparator,
29 is a differentiator, 30 is a one-shot circuit, 31 is a switch, 32 is an integrator, 33 is an inverting amplifier, 34 is a switch, 35 is a direction discriminator, and 36 is a differentiator.

The operation of the speed/acceleration detection device configured as follows will be described below.

First, the A-phase sine wave is converted into a rectangular wave by the comparator 27, and this rectangular wave is differentiated by the differentiator 29 to form a whisker-like waveform. This whisker-like waveform is converted into a pulse train with a predetermined width by the one-shot circuit 30, and this pulse train turns the switch 31 on and off.
The current flowing at this time is integrated by an integrator 32. That is, the output voltage of the integrator 32 becomes a voltage proportional to the width of the pulse train output from the one-shot circuit 30.

The A-phase sine wave and the B-phase sine wave are each sent to a comparator 27.
28 converts it into a rectangular wave and inputs it to the direction discriminator 35. The direction discriminator 35 discriminates the direction by comparing the phases of the A-phase rectangular wave and the B-phase rectangular wave, and switches the switch 34. The switch 34 switches between the output of the integrator 32 and the output obtained by inverting the output of the integrator 32 by the inverting amplifier 33. As a result of the above, the output of the switch 34 becomes a speed signal expressing the direction of rotation as positive or negative.

The signal is differentiated by a differentiator 36 and becomes an acceleration signal.

Problems to be Solved by the Invention However, in the above configuration, although the linearity between the frequency of the A-phase sine wave and the speed signal is good at high frequencies, the speed signal ripple becomes large at close frequencies, and a phase lag also occurs. . Therefore, ripples and phase delays occur in the acceleration signal, and there is a limit to the accuracy of the speed signal and acceleration signal.

In positioning control of industrial robots, a signal of a similar frequency is input from a position detection device near a target position, so there has been a problem in that speed/acceleration signals with good controllability cannot be obtained in this case.

In view of the above problems, the present invention provides a speed/acceleration detection device that obtains highly accurate speed and acceleration signals with little ripple and phase delay even when the frequencies of the output signals of the position detection device are close.

Means for Solving the Problems In order to solve the above problems, the speed/acceleration detection device of the present invention uses an A-phase sine wave with a 90° phase difference.

a position detection device that outputs a B-phase sine wave; a position detection device that differentiates the A-phase sine wave and the B-phase sine wave; and the A-phase sine wave;
The multiplier includes two multipliers for differentiating the phase B and the second differential value of the A phase and the B phase, and a subtracter for calculating the difference between the outputs of these multipliers. However, in the acceleration detection device, the differentiator outputs second-order differential values of the A-phase sine wave and the B-phase sine wave.

According to the above configuration, the present invention calculates the product of the differentiation of phase A and phase B, and the product of differentiation of phase B and phase A, respectively, and calculates the difference between these two products to eliminate ripples and phase lag in the entire band. It is possible to obtain two velocity signals and two acceleration signals.

EXAMPLE Below, a speed/acceleration detection device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a speed detection device in a first embodiment of the present invention. In the figure, 1 and 2 are differentiators, 3 and 4 are multipliers, and 5 is a subtracter.

The operation of the speed detection device configured as described above will be explained below with reference to FIG.

The A-phase sine wave and the B-phase sine wave with a 90° phase difference output from the position detection device (not shown) are each Ks in
(2πx/λ) and K cos (2πx/λ). Here, K is the amplitude of the A phase and B phase, X is the displacement of the position detection device, λ is the slit width of the position detection device, and π is the circumference ratio. A phase sine wave.

The B-phase sine wave is differentiated by differentiator 1.2, respectively,
K(2πx/λ) cos (2πx/λ).

−K (2πx/λ)s in (2πx/λ).

X indicates the time derivative of the displacement X, that is, the velocity. Multiplier 3 differentiates the A phase and the product of the B phase, K (2πX/λ)cos2
(2πX/λ), and the multiplier 4 differentiates the B phase and outputs the product of the A phase, −K (2πX/λ) sin2 (2πX/λ). Subtractor 5 calculates the difference between the outputs of multipliers 3 and 4, (2π
/λ)Kx(sin (2πX/λ) +cO62(2πx/λ) )= (2π/λ)K"x
However, since (2π/λ)K is a constant, it can be seen that the output of the subtracter 5 is a speed signal with extremely little ripple and phase lag in the entire band.

As described above, according to this embodiment, the differentiator 1,
2 and a multiplier 3.4, and a subtracter 5 for obtaining a speed signal by calculating the difference between these two products, ripples can be eliminated in all bands regardless of the frequency of the output of the position detection device. In addition, it is possible to obtain a speed signal with excellent controllability and extremely little phase delay.

FIG. 3 is a configuration diagram of an acceleration detection device in a second embodiment of the present invention.

In the same figure, 16.17 is a multiplier, 18 is a subtracter,
The above is similar to the first embodiment. The difference from the configuration of the first embodiment is that the differentiators 14 and 15 perform second-order differentiation.
The point is that

The operation of the acceleration detection device configured as described above will be described below.

In FIG. 3, an A-phase sine wave and a B-phase sine wave with a 90" phase difference output from a position detection device (not shown) are Ks in (2πX/λ) and Kcos (
2πX/λ). However, K is the amplitude of the A phase and B phase, X is the displacement of the position detection device, λ is the slit width of the position detection device, and π is the production rate. The A-phase sine wave and the B-phase sine wave are second-order differentiated by the differentiator 14゜15, and are respectively -K (2zx/λ) stn (2πx/λ) + K (2π
X/λ) cos (2πX/λ)−K(2πX/λ)c
os (2πX/λ)K(2πx/λ)s in (2
πx/λ). However, X indicates the time differential of the displacement X, that is, the velocity, and X indicates the second order differential of the displacement X with respect to time, that is, the acceleration. The multiplier 16 calculates the product of A phase and B phase, K2 (2yrx/λ) s J n (2yrx/λ
) cos (2πX/λ) 2(2πx/λ) cos (2πX/λ) is output, and the multiplier 17 outputs the product of B phase and A phase, K'(2zx/λ) 5tn(2 'rx/λ)cos
(2πX/λ) +2(2'r”x/λ)s in2(2πx/λ)
Output. The subtracter 18 calculates the difference between the outputs of the two multipliers 16 and 17, (2π/λ)K2°x ls ln <2yrx/λ
)+cos (2πX/λ) )= <2yc/λ)
Since (2π/λ)K is a constant, it can be seen that the output of the subtracter 18 is an acceleration signal with extremely little ripple and phase lag in the entire band.

As described above, according to this embodiment, a differentiator (second order differential) 14.15 and a multiplier 16.17 are provided in order to obtain the product of the A phase and the B phase and the product of the B phase and the A phase. By providing a subtracter 18 to obtain an acceleration signal by calculating the difference between these two products, the acceleration can be easily controlled with extremely little ripple and phase delay in all bands, regardless of the frequency of the output of the position detection device. I can get a signal.

I can do that.

Note that the multiplier in the first embodiment may be constructed of a logarithm, an adder, and an anti-logarithm, as shown in FIG.

Furthermore, the multiplier in the second embodiment may be constructed of a logarithm, an adder, and an anti-logarithm, as shown in FIG.

Effects of the Invention As described above, the present invention provides a position detection device that outputs A-phase and B-phase sine waves with a 90° phase difference, a position detection device that outputs A-phase differentials, B-phase differentials, and By providing a multiplier that outputs the product of the differential of phase and B phase and the product of the differential of A phase and B phase, and a subtractor that outputs the difference between these two products,
Regardless of the frequency of the output of the position detection device, it is possible to obtain velocity/acceleration signals with good controllability with little ripple and phase delay over the entire band.

[Brief explanation of drawings]

1 and 2 are block diagrams of a speed detecting device according to a first embodiment of the present invention, FIGS. 3 and 4 are block diagrams of an acceleration detecting device according to a second embodiment of the present invention, and FIG. The figure is a configuration diagram of a conventional speed/acceleration detection device. 1.2... Differentiator, 3, 4... Multiplier, 5... Subtractor, 6.7, 8.9...
Logarithm, 10.11... Adder, 12.13.
・・・・・・Antilogarithm, 14.15・・・Differentiator (
second-order differential), 16.17...multiplier, 18...
...Subtractor, 19.20.21.22...
Logarithm, 23.24... Adder, 25.26.
...Antilogarithm.

Claims (4)

[Claims] (1) A position detection device that outputs A-phase and B-phase sine waves with a 90° phase difference depending on changes in position, and a differential value of the A phase that is obtained by differentiating the output signals of the A phase and B phase of this position detection device, respectively. two differentiators that output a differential value of the B phase, two multipliers that multiply the differential value of the A phase by the B phase, and the differential value of the B phase and the A phase, and these multipliers. 1. A speed detection device comprising: a subtractor for determining the difference between the outputs of the speed detectors. (2) The speed detection device according to claim 1, wherein the multiplier comprises a logarithm, an adder, and an antilogarithm. (3) A position detection device that outputs A-phase and B-phase sine waves with a 90° phase difference by position conversion, and a second-order differential of the output signals of the A-phase and B-phase, respectively, of the A-phase
Two differentiators that output a differential value and a second differential value of the B phase, two differentiators that multiply the second differential value of the A phase by the B phase, and the second differential value of the B phase by the A phase, respectively. An acceleration detection device comprising: a multiplier; and a subtracter that calculates a difference between the outputs of these multipliers. (4) The acceleration detection device according to claim 3, wherein the multiplier comprises a logarithm, an adder, and an antilogarithm.