JPS61235911A - Position detecting device - Google Patents

Abstract

PURPOSE:To obtain a position feedback signal of a high resolution and a high speed response by switching two circuits, and feeding back an output signal of a detecting circuit of a high resolution and a low response speed in case of a low speed, and an output signal of a detecting circuit of a low resolution and a high response speed in case of a high speed. CONSTITUTION:An inversion signal 23 of a signal 22 is outputted from an F terminal. In case a speed is low, an output signal 13u of an AND circuit 18 remains a low level, but an output signal 12u of an AND circuit 20 outputs a counting pulse 8u of a high resolution as it is. In case a speed is high, the output signal 13u of the AND circuit 18 outputs a counting pulse 9u of a low resolution, but the output signal 12u of the AND circuit 20 remains a low level. When the signal of 13u is fed back to a controller 2, it is decided that the number of pulses of (n) times of the number of counting pulses of 13u has been fed back and it is processed in the controller 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a position detection device used in a positioning device that controls the position of a moving object by feeding back the speed and position of the moving object to a control device.

[Background of the invention]

Rotary encoders and linear scales are widely used as position detectors in this type of positioning device. However, although rotary encoders and linear scales can improve measurement resolution by using detection circuits, they have the disadvantage that increasing resolution reduces response speed. As a way to improve this drawback,
As shown in the publication, it is equipped with a detection circuit with high resolution and low response speed and a detection circuit with low resolution and high response speed, and detects the speed of a moving object using the output signal of the low resolution detection circuit. There is a speed switching type position detector that uses a high-resolution device to accurately detect the position of a moving object when the speed is low, and uses a low-resolution device to roughly detect the position of the moving object when the speed is high.

By the way, in a control system such as a positioning device, velocity information in addition to position information is obtained as a feedback signal by a tacho generator or by performing approximate differential calculation of position information using a microcomputer or the like. However, in the above-mentioned speed switching type position detector, when the signal is used as a position feedback signal of the Jl el J system, the configuration is not such that the speed information of the speed feedback signal is used to switch between the two position detection circuits. Therefore, a high-resolution, high-speed response position feedback signal cannot be obtained.

[Purpose of the invention]

An object of the present invention is to provide a position detection device that can obtain a position feedback signal with high resolution and high speed response.

[Summary of the invention]

The present invention is equipped with a circuit that detects position information at low resolution but at high speed in the position feedback part of the control system of a positioning device, and a circuit that can detect position information at high resolution but at low response speed. The system speed feedback signal is used to switch between the two circuits. In other words, in the case of low speed, the output signal of the detection circuit with high resolution and low response speed is fed back, and in the case of high speed, the output signal of the detection circuit with low resolution and high response speed is fed back, thereby achieving high resolution and high response. The velocity position feedback signal is obtained r
It was made by sea urchin.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. FIG. 1 shows a block diagram of a control system of a positioning device implementing a position detection device according to the present invention.

In FIG. 1, a controller 2 receives a position command signal 1, position feedback signals 12 and 13, and a speed feedback signal 15, and sends a signal for driving the motor 4 to a driver 8. Further, the controller 2 determines from the speed feedback signal 16 that the current moving speed of the table 6 (
The speed is binarized depending on whether it is lower or higher than a certain arbitrary speed (rotation speed of the motor 4), and the binarized speed signal 1
1 to the switching device 10. The driver 8 sends a current for driving the motor 4 to the motor 4 in response to a signal from the controller 2 . A ball screw 5 is attached to the rotating shaft of the motor 4, and the table 6 is moved in a straight line by the ball screw 5. Further, a rotary encoder 7 and a tacho generator 14 are attached to the rotating shaft of the motor 4, and each generates signals corresponding to the position and speed of the table 6. The position signal from the rotary encoder 7 is sent to a high-resolution detection circuit 8 that performs high-resolution detection at a low response speed and a low-resolution detection circuit 9 that performs low-resolution detection at a high response speed. The switch 10 sends the signal from the high-resolution detection circuit 8 to the controller 2 as a position feedback signal 12 when the speed is low using a binary speed signal 11 . Furthermore, when the speed is high, the signal from the low resolution detection circuit 9 is sent to the controller 2 as a position feedback signal 18.

Here, for example, the rotary encoder 7 is N per rotation.
When outputting a circular signal, the low-resolution detection circuit 9 generates a counting pulse of 1) mxN@ per rotation of the rotary encoder 7, and the high-resolution detection circuit gVi generates 1 count pulse of the rotary encoder 7.
Suppose that a counting pulse of rotation frequency nXmXN is generated. In this case, when the binarized speed signal 11 is high speed, the position feedback signal 18 is sent from the low resolution detection circuit 9 to the controller 2. At this time, the number of counted pulses of the position feedback signal 18 is The position information is multiplied by n, so that it appears that the position information is always being fed back from the high-resolution detection circuit 8. With the above configuration, the table 6rt can be positioned at high speed and with high precision.

FIG. 2 shows a specific example of the switching device 10, with 8u, g
af'i High resolution detection circuit 8 output signal, 9u, 9d
is the output signal of the low resolution detection circuit 9. 12u, 12
d is the output signal of the high-resolution switch 10, 18u, 18
(This is the output signal of the lid low resolution switch lO.8
u, 9u, 12u, 18U are signals when the rotary encoder 7 is in a certain direction of rotation;
11 (L is the signal when rotating in the opposite direction. 16 is O
The signals 9U and 9d are input manually in the R circuit and the signal 9' is output.

17 is Edge Triggered Delayei Flip-
In the flop circuit (edge triggered D-F, F), T
The output signal 9' of the OR (b) path 16 is input to the terminal, and the D
A binarized speed signal 11 is input to the terminal. 18.
19, 20, and 21 are AND circuits, and the AND circuit 18 receives the output signal 9u of the low resolution detection circuit 9, the F output signal 22 of the F17, and the output signal 9u of the low resolution detection circuit 9.
Outputs 8u. The AND circuit 19 includes the output signal 9d of the low resolution detection circuit 9 and the edge trigger DF, F17.
of? The output signal 22 is input and the signal &(L is output.

The AND circuit 20 receives the output signal 8u of the high-resolution detection circuit 8.
and edge triggered D-F, p output signal 28 of F17
is output, and a signal 12u is output. ANI) circuit 21
The output signal 8d of the high-resolution detection circuit 8 and the edge triggered D-IP, F17! The output signal 28 is manually generated,
A signal 12al is output.

Figure 8 shows the rotational direction of the rotary encoder 7 (8u and 9u from the high-resolution detection circuit 8 and low-resolution detection circuit 9).
The time chart shows the rotation direction in which the signal is output. Next, the operation of the switching device 10 shown in FIG. 2 will be explained using FIG. 8.

High resolution counting pulse 8u is low resolution counting pulse 9u
n pulses for 1 pulse (n = = l in the 8th Jl)
A counting pulse (Q pulse) is generated. Also, 2
The value conversion speed signal 11 is designed to output a high level signal when the speed exceeds a certain value. 9u to OR circuit 16
When the signal 9 is input manually, the same signal is output as the output signal 9'. This output signal 9' edge triggered D-F1
7 and the binarized speed signal 11 to the D terminal, a signal 22 that becomes high level or low-pel at the timing of the low resolution counting pulse 9u from the edge triggered D-FP 17 is sent to the y terminal. is output from. An inverted signal 28 of the signal 22 is output from the F terminal. i.e. if the speed is low? The output signal 22 of the terminal is low level or? When the output signal 28 of the terminal is high level, A
The output signal 18u of the ND circuit 18 remains at a low level, but the output signal 12u of the II) circuit 20 outputs the high-resolution counting pulse 8u as it is. If the speed is high,
That is, when the output signal 22 of the 11' terminal is at a high level or the output signal 28 of the F terminal is at a low level, the output signal 18u of the AND circuit 18 outputs a low-resolution counting pulse 9u, but the output signal of the AlfD circuit 20 12u remains at low level. When the taU signal is fed back to the controller 2, the taU signal is
Processing is performed assuming that the number of valves is fed back, which is n times the number of counted pulses (m=10 times in FIG. 8). The same applies when the rotation direction is the opposite direction.

By the above method, it is assumed that the position signal is constantly being fed back from the high-resolution circuit 8 within the controller 2, and high-accuracy and high-speed positioning is possible.

For example, the resolution of the low-resolution detection circuit is 40 μm when converted to the linear movement of the table, and the response speed is 1 m/a, and the resolution of the high-resolution detection path is 4 μm, and the response speed is Q, 1.
m/a, if the boundary speed of binarization is set to Q, 1 m/8 or less, the final resolution is 4 μm and the response speed is l.
A position feedback signal of m/s can be obtained.

FIG. 4 shows another embodiment of the present invention, which differs from FIG. The operation is the same as that of the previous embodiment, in that the speed feedback signal is used to obtain the binarized speed signal 11.

The present invention is not limited to the above-mentioned rotary encoder, but can also be applied to a linear scale or a laser length measuring device.

〔Effect of the invention〕

As described above, according to the present invention, a high-resolution and high-speed response position feedback signal can be obtained, thereby enabling high-speed and high-precision positioning.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is a block diagram of the control system of the positioning device implementing the position detection device t according to the present invention, and FIG. FIG. 8 is a time chart diagram of FIG. 2, and FIG. 4 is a block diagram showing another embodiment of the present invention. 1...Position command signal 2...Controller 3...
・Dryper, 4...Motor 5...Ball screw 6
...Table 7...Rotary encoder 8...
・High resolution detection circuit 9...Low resolution detection circuit 10
...Switcher 11...Binarized speed signal 12
．． 12u, 12d... High resolution position feedback signal, 18, tau, taa-... Low resolution position feedback signal 14... Tacho generator 15...
・Speed feedback signal 16...0RIQ path 1
7... Edge Trigger Delayed] F11
p-flop circuit, 18.19.20.21...AN
D circuit 22.28-Zy-triggered Delay
a ] H1p-flop circuit output signal m °13ν

Claims (1)

[Claims] A positioning device that controls the position of a moving object by feeding back the speed and position of the moving object to a control device includes a position detector (A) with high detection resolution that feeds back a detection signal to the control device when the speed of the moving object is low; , a position detector (B) with a low detection resolution that feeds back a detection signal to the control device when the speed of the moving body is high, and a position detector (A) that uses the speed feedback signal to feed back a detection signal to the control device. , a position detection device characterized in that the feedback from the position detector (B) to the control device is switched.