JPS6032805B2 - Counting pulse generator - Google Patents

Description

[Detailed Description of the Invention] Generally, when controlling the position of a moving object, the counting pulses from the encoder are counted using a reversible counter, and if the moving direction of the moving object is in the forward direction, it is added, and if it is in the opposite direction, it is subtracted. It is necessary to always match the position of the moving object and the contents of the counter.

In the secondary method of outputting a count-type actuation pulse, a count actuation pulse is output at a fixed point of the encoder output (for example, the intersection point of the B waveform and the reference level as shown in FIG. 1).

As a result, when the moving body vibrates near point X, a count operation pulse is outputted N times that the pulse crosses point X, and the reversible counter subtracts or adds N times, making the position of the moving body unclear. The object of the present invention is to eliminate the above-mentioned drawbacks, and to prevent the output of erroneous counting pulses due to vibration at the X point.

2-a and 2-b show an encoder output waveform having two phases of A and B waves when the moving body is moved in the forward direction, and an encoder output waveform when the moving body is moved in the reverse direction.

a,,a2,b. , b2, c, , c2, d, , d2 indicate the intersection of a certain reference level and the B waveform. If the moving direction of the moving body is now the forward direction, the encoder waveform will become as shown in Fig. 2-a, and a. , 2... points are used to determine the direction. At this time, the A waveform shows positive polarity. Also, at points q, 2, . . . , a count operation pulse is output, and the A waveform at this time is of negative polarity. Next, when the moving direction of the moving body is reversed, the encoder waveform becomes as shown in Fig. 21b, c, 2...
・Perform direction determination using points. At this time, the A waveform shows negative polarity. Further, a count operation pulse is output at points d, 2, . . . , and the A waveform at this time shows positive polarity. In the present invention, in order to output a count operation pulse, first determine the moving direction of the moving object, then check the polarity of the A waveform when outputting the count operation pulse, and if the moving object vibrates near the same counting point, Only the first pulse of the count operation pulse is output, but pulses generated afterward due to vibration are not output. Examples of the present invention will be described in detail below.

FIG. 3 is a circuit diagram of the device of the present invention.

In Figure 3, 1 and 2 are Schmitt circuits that convert a sine wave into a rectangular wave, which is not necessary if the encoder output waveform is a rectangular wave. o From this circuit 1 and 2, the a and b rectangular waves are the same as the b waveform. The polarity of the a waveform is checked at the rising edge, and if it is positive, it is determined that the moving direction of the moving object is the forward direction, and if it is negative, it is determined that the moving direction is the reverse direction.The input is input to the known direction judgment circuit 3, and the direction is determined, and the polarity differs depending on the direction of the moving object. The output waveform c is input to the ND circuit 7 and to the *ND circuit 8 via the inverter 5.

Further, in order to check the polarity of the a waveform when outputting the count operation pulse, the output from the Schmitt circuit 1 is input to the *ND circuit 8 and to the 3AND circuit 7 via the inverter 6. Further, the output b of the Schmitt circuit 2 is input as a count pulse to the milk ND circuits 7 and 8 through the inverter 4. When the 3AND circuits 7 and 8 perform an AND operation, output waveforms d and e are generated, and the output waveforms d and e are outputted via the OR circuit 9 to the count operation pulse B.
' is output.

Now, if the traveling direction of the moving object is the forward direction, the one at the level is obtained as the discrimination signal c, and the AND of each waveform a, c, and b input to the pine ND circuit 7 is established, and the d waveform is output. be done.

The d waveform passes through the OR circuit 9 and becomes the f waveform, that is, the count operation pulse B'. At this time, the AND of the a and c waveforms input to the 3AND circuit 8 is not established, and no output is generated. Next, in the case of the reverse direction, the AND of the a, c waveforms input to the 3AND circuit 7 is not established and no output is generated, and the AND of the a, b, c waveforms input to the 3AND circuit 8 is established, and the pulse f is generated. Output. FIG. 5 shows a case where the moving body vibrates when it is stopped, and as the B waveform vibrates at the point where the count operation pulse is generated, B waveform pulses are generated for the number of vibrations. However, as shown in Fig. 5, after the last count operation pulse f' is output (point P of the B waveform), the moving direction of the moving object is reversed.
At the time of the next rising edge, the direction determining circuit 3 operates, causing the c waveform level L to fall. Point Q between the B waveform and the reference level
When it reaches , it reverses again, the b waveform falls, a count operation pulse is generated, and the *ND circuits 7 and 8 pass through the inverter 4.
is input to. However, in the 3AND circuit 7, since the c waveform falls to level L, the AND is not established and no output is made. Also, the Kasa ND circuit 8 becomes AN when the a waveform falls to level L.
D does not hold and is not output. That is, in the present invention, the direction is necessarily determined, and the count operation pulse is generated after the direction determination signal is generated, and the polarity of the A waveform is checked, and the count operation pulse is output only when these conditions are met. It is possible to prevent count operation pulses caused by vibrations or the like at the same point on the moving body.

[Brief explanation of drawings]

Figure 1 is an encoder output waveform diagram, Figure 2-a, Figure 2-b
The figures are two-phase output encoder waveform diagrams when the moving direction of the moving body is forward and backward, Figure 3 is a circuit diagram of a counterfeit counterfeit that outputs count operation pulses of the present invention, Figures 4 and 5 The figure is an explanatory waveform diagram. 1, 2... Schmitt circuit, 3... Direction judgment circuit, 4, 5, 6... Inverter, 7, 8... Father WD circuit, 9... OR circuit. Spear l illustration 2-q illustration 2-b illustration 3 illustration illustration 4 illustration illustration 5

Claims (1)

[Claims] 1. Detect the movement of the moving object and detect the first,
an encoder that generates second signals a, b;
a direction discrimination circuit that generates a discrimination signal c having a different polarity depending on the moving direction of the moving object from the second signals a and b;
The inverted signal ■ of the signal a, the discrimination signal c, and the second signal b
A first 3AND circuit 7 receives an inverted signal (■) of the first signal waveform a, an inverted signal (■) of the discrimination signal c, and an inverted signal (■) of the second signal b. 3AND
It consists of a circuit 8 and an OR circuit 9 which receives the outputs of the first and second 3AND circuits 7 and 8, respectively, and the output of the OR circuit 9 is taken out as a count operation pulse. Count actuated pulse generator.