JPH0456926B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a length measurement and positioning method and apparatus, and more specifically, a length measurement and positioning method and apparatus using a linear induction motor and a linear pulse motor in combination. Regarding equipment.

(Prior Art) In recent years, high-speed and highly accurate length measurement or positioning has been required in various fields, such as measuring the length of a material to be cut in a shearing machine or positioning a magnetic head.

On the other hand, when conventional length measurement or positioning is performed, a linear length measuring device or a rotary length measuring device is used, and the rotary motion is converted into linear motion using a rotary motor as the power. Length measurement or positioning was carried out by moving the instrument, the object to be measured, or the object to be transported. More specifically, for example, the object to be measured or the object to be conveyed is linearly moved by driving a motor to rotate through the frictional force with a rotating member connected to its rotating shaft, and the moving distance is calculated using Magnescale. Measure with a linear length measuring device such as
Alternatively, the measurement is calculated by calculating the rotation speed of the motor's rotating shaft or the rotating member connected to it using a rotational measuring device such as a tachometer generator, and the measured value is compared with a preset setting value to set the measured value. When the values match, the motor is stopped and length measurement or positioning is performed.

(Problems to be Solved by the Invention) According to such conventional methods, in order to move the object to be measured or the object to be transported in a linear direction, frictional force between the object and the rotating member connected to the rotating shaft of the motor is required. As a result, the diameter of the rotating member, which is the basis for calculating the moving distance of the object to be measured or conveyed, may change due to wear due to friction, resulting in errors, or errors may occur due to the inertia of the object to be measured or conveyed. Errors were occurring due to movement after stopping. This drawback becomes more noticeable the more you try to achieve high speed.

The problem to be solved by the present invention is to eliminate the above-mentioned drawbacks of the prior art.

In order to eliminate the above drawbacks, attempts have been made to move the object to be measured or conveyed using a linear induction motor or a linear pulse motor; When moving objects, it is possible to move them at high speeds and over long distances, but when stopping the object to be measured or the object being transported, it is difficult to position with high precision (for example, 1/100 or less). However, if a linear pulse motor is used to move the object to be measured or transported, highly accurate positioning is possible, but it is difficult to manufacture a long slit plate to move the linear pulse motor. Therefore, it is difficult to move the object to be measured or the object to be transported over a long distance.

Therefore, we have established a measurement method that maintains high speed while ensuring measurement accuracy is not affected by wear. Furthermore, we have developed a method that uses linear pulse motors even when moving objects to be measured or transported over long distances. It is an object of the present invention to provide a high-speed, high-precision length measurement and positioning method, and an apparatus therefor, which can ensure measurement accuracy equivalent to that in the conventional case.

(Means for Solving the Problems) In order to solve the above problems, the length measurement and
The positioning method uses a linear induction motor, a linear pulse motor, and a relative displacement detection means for detecting whether the moving object has reached a coarse setting range, an actual moving distance, or a set moving distance. The carrier is movable on a running rail by the linear induction motor, and the linear pulse motor is provided on a surface of the carrier opposite to the running rail, and the linear pulse motor is set from the outside. A linear pulse motor carries the object to be moved by a certain distance, and when the moving distance is set from the outside, a coarse setting range is determined according to this set moving distance, and the linear induction motor is first driven. , the object to be moved is moved at high speed until it reaches a coarse setting range, and then the linear pulse motor is driven by a pulse signal according to the deviation between the actual movement distance of the object by the linear induction motor and the set movement distance. The moving object is positioned and stopped with high accuracy so that the moving object reaches the set moving distance.

Further, the length measuring/positioning device of the present invention includes a carrier driven by a linear induction motor, a linear pulse motor supporting a moving object and movably mounted on the carrier, and a carrier driven by a linear induction motor. A linear length measuring device (linear scale) consisting of a fixed member fixedly arranged along a moving path and a moving member supported by a linear pulse motor.
and an arithmetic and control device for controlling the drive of the linear induction motor and the linear pulse motor, the carrier is movable on the running rail by the linear induction motor, and the linear The pulse motor is provided on the surface of the carrier opposite to the running rail, and the arithmetic and control unit determines a rough setting range with respect to the moving distance of the object set from the outside, and sets the range within this coarse setting range. The linear induction motor is driven by the corresponding distance, and in response to the linear scale detecting that the object to be moved has reached the rough setting range, the linear induction motor is stopped, and the linear induction motor is stopped. Based on the actual moving distance of the moving object measured by the scale and the moving distance of the moving object set from the outside, a linear pulse motor is driven to move the moving object over the moving distance set from the outside. The present invention is characterized in that it is configured to calculate the number of drive pulses required to move the remaining distance until reaching , and apply the number to the linear pulse motor.

Furthermore, in the method and apparatus of the present invention, it is desirable that each coarse setting range is determined to be a distance range that is greater than or equal to the stopping precision that can be ensured by the linear induction motor with respect to the set travel distance.

(Function) According to the present invention, as described above, with respect to the travel distance setting value inputted from the outside, within the arithmetic and control device, the stopping accuracy is greater than or equal to that which can be ensured by the linear induction motor. The coarse setting range is calculated and determined, and the linear induction motor is started in response to a start command, and after moving the object at high speed, it is stopped when the coarse setting range is reached. At this time, the actual moving distance of the object to be moved is measured using a linear scale, and the deviation value between the actual moving distance measurement value and the moving distance setting value from the outside is calculated by the arithmetic and control device, and the deviation value is Accordingly, the number of pulses to drive the linear pulse motor is calculated, the linear pulse motor is driven by the pulse signal, and the stopping accuracy of the linear pulse motor is determined based on the set value of the external movement distance of the moving object. Stop inside.

(Example) An example of the present invention will be described in detail below with reference to FIGS. 1 to 3 of the drawings. According to this embodiment, a carrier 12 is driven and moved by a linear induction motor 10, and a linear pulse motor 1 is movably mounted on the carrier 12.
4, a linear length measuring instrument (hereinafter referred to as a linear scale) 20 consisting of a fixed member 16 fixedly arranged along the moving path of the carrier 12 and a moving member 18 supported by a linear pulse motor 14;
An arithmetic and control unit 22 is provided to control the driving of the linear induction motor 10 and the linear pulse motor 14. Two running rails 24 are arranged on the moving path of the carrier 12, and the carrier 12 runs on the running rails 24 by wheels 26 provided thereon. Further, a reaction plate 28 for the linear induction motor 10 is disposed between the running rails 24, and a slit plate 30 for advancing the linear pulse motor 14 is disposed on the upper surface of the carrier 12. Ru. Although the object to be moved carried by the carrier 12 is not shown here, the object to be moved may be, for example, a marking means, a magnetic head, etc., carried by the carrier 12.
Alternatively, the moving member 18 of the linear scale 20 itself may be the object to be moved.

A movement distance setting signal is input to the arithmetic and control device 22 from the outside via the signal line 30A, and a rough setting range is determined within the arithmetic and control device 22 according to the movement setting value. This rough setting range is calculated and determined in accordance with a program stored in advance in a microcomputer built into the arithmetic and control device 22 or something similar. In that case, it is desirable to determine the rough setting range with a value that is greater than the stopping accuracy that can be ensured by the linear induction motor 10. This means, for example, that the travel setting value is 100mm.
If the stopping accuracy of the linear induction motor 10 is ±10 mm, the stopping range that can be secured by the linear induction motor 10 is
100±10mm, and the rough setting range is larger than that.
For example, this means determining 100±15mm. These movement setting values and coarse setting ranges are stored in a storage means inside the arithmetic and control unit 22. When the calculation of the rough setting range is completed, the calculation and control unit 22 automatically applies a start signal to the linear induction motor 10 via the signal line 32, drives the linear induction motor 10, and moves the carrier 12. let As the carrier 12 moves, the moving member 18 of the linear scale 20 also moves along the fixed member 16, and information regarding the actual moving distance of the object to be moved is sent to the arithmetic and control unit 22 via the signal line 34 from time to time.
given to. This actual travel distance is determined by the arithmetic and control unit 2.
2, and when the actual moving distance reaches the coarse setting range, for example, when the actual moving distance reaches 85 mm in the above example, the arithmetic and control unit 22 sends the signal via the signal line 32. A stop signal is given to the linear induction motor 10 to stop it, and the actual travel distance information from the linear scale 20 when the carrier 12 stops is used as the stored travel distance setting value from the outside. Compare them, calculate the deviation between them, that is, the distance to which the moving object (that is, the linear pulse motor) should be further moved, and calculate the number of pulses according to the calculated value, that is, the step of the linear pulse motor 14. Then, a pulse signal having a number of pulses such that the deviation is made zero is applied to the linear pulse motor 14 via the signal line 36 to drive the linear pulse motor 14 step by step. The linear pulse motor 14 moves to a predetermined movement setting value according to the applied pulse signal and then stops with high precision. Taking the above example again, if the actual moving distance when the linear induction motor 10 stops is 95 mm, a pulse signal with the number of pulses corresponding to the remaining distance of 5 mm is applied to the linear pulse motor 14, Also, if for some reason the actual travel distance exceeds the travel setting value and is 103 mm, a reverse polarity pulse signal with the number of pulses corresponding to the excess distance of 3 mm is applied, and the linear pulse motor 14 is driven in the reverse direction. be done.

In the above embodiment, the activation signal for the linear induction motor 10 is described to be automatically generated and applied from the arithmetic control unit 22 when the calculation of the coarse setting range is completed. After waiting, a starting signal may be further input from the outside to the arithmetic and control unit 22 via the signal input line 38, or one of them may be selected as desired. Note that the reference numeral 40 is a power supply line for energizing. The feeder line 40 and each signal line 32, 34, 36, 38 are housed within a cable 42 as shown in FIG.

(Effects of the Invention) As described above, according to the present invention, the carrier is movable on the traveling rail by the linear induction motor, and the carrier is linearly movable on the side opposite to the rail.・By attaching a pulse motor and making the object move freely in a direction parallel to the traveling rail, the object is initially moved at high speed by a linear induction motor, and the actual distance traveled is measured with a linear scale. The linear induction motor is stopped when it reaches the coarse setting range determined according to the set travel distance, and the number of pulses calculated from the deviation between the actual travel distance and the set travel distance is calculated. The linear pulse motor is driven by the drive pulse signal, and when the object to be moved reaches a predetermined travel setting distance, it is positioned and stopped with high precision, so the linear pulse motor is
While ensuring the high speed of an induction motor and the high accuracy of a linear pulse motor, it is possible to perform high-speed, high-precision length measurement and positioning without being affected by mechanical wear. As a result,
The present invention utilizes the features of both linear induction motors and linear pulse motors to achieve high-speed, high-precision feeding and positioning of a moving object in the same one-dimensional direction. have an effect.

[Brief explanation of the drawing]

Figure 1 shows the high-speed and high-precision length measurement method according to the present invention.
FIG. 2 is a front view showing an embodiment of the positioning device, FIG. 2 is a side view thereof, and FIG. 3 is a signal circuit block diagram for explaining control by the arithmetic and control unit in the above embodiment. Explanation of symbols, 10... Linear induction motor, 12... Carrier, 14... Linear pulse motor, 20... Linear scale, 22...
Arithmetic control unit.

Claims (1)

[Claims] 1. Relative displacement amount detection for detecting whether the linear induction motor, linear pulse motor, and moving object have reached the coarse setting range, the actual movement distance, or the set movement distance in the carrier. and means;
The carrier is movable on a running rail by the linear induction motor, and the linear pulse motor is provided on a surface of the carrier opposite to the running rail,
A linear pulse motor carries the object to be moved by an externally set distance, and when the moving distance is set externally, a rough setting range is determined according to this set moving distance, and the linear induction The motor is driven to move the object at high speed until it reaches the rough setting range, and then the linear induction motor is used to move the object at high speed using a pulse signal corresponding to the deviation between the actual movement distance of the object and the set movement distance. A length measurement and positioning method using a linear induction motor and a linear pulse motor, characterized in that the pulse motor is driven to position and stop the moving object with high precision so that the object reaches the set travel distance. 2. The linear induction motor according to claim 1, wherein the coarse setting range is determined to be a distance range that is greater than or equal to the stopping accuracy that can be secured by the linear induction motor with respect to the set moving distance.・Length measurement and positioning method using pulse motor. 3. A carrier driven by a linear induction motor, a linear pulse motor that supports a moving object and is movably mounted on the carrier, and a fixed motor that is fixedly disposed along the moving path of the carrier. The carrier is equipped with a linear length measuring device (linear scale) consisting of a member and a moving member carried by a linear pulse motor, and an arithmetic control device that controls the driving of the linear induction motor and the linear pulse motor. The linear induction motor allows the carrier to move freely on the running rail, and the linear pulse motor is provided on a surface of the carrier opposite to the running rail, and the arithmetic and control unit includes:
A coarse setting range is determined for the moving distance of the moving object that is set from the outside, and the linear induction motor is driven by a distance corresponding to this coarse setting range, and when the moving object reaches the coarse setting range, The linear induction motor is stopped in response to the detection by the linear scale, and the actual moving distance of the moving object measured by the linear scale and the movement of the moving object set from the outside are determined. From the distance, calculate the number of drive pulses required to drive the linear pulse motor to move the object the remaining distance until it reaches the externally set travel distance, and apply it to the linear pulse motor. A length measuring and positioning device that uses a linear induction motor and a linear pulse motor in combination. 4. The linear motor according to claim 3, wherein the rough setting range is determined to be a distance range that is greater than or equal to the stopping accuracy that can be ensured by the linear induction motor with respect to the moving distance of the moving object set from the outside.・Length measurement and positioning device that uses both induction motor and linear/pulse motor.