JPS6174013A - Positioning device - Google Patents

Abstract

PURPOSE:To simplify a circuit, and also to omit an origin reset of a movable body of the time of restart, etc. after a service interruption by executing a positioning control by detecting an absolute position of the movable body. CONSTITUTION:A speed data is read out of a ROM1 which stores a single speed pattern for stopping a movable body 5 at a specified position, and inputted to a servo-motor 4 through a D/A converter 2 and a driving circuit 3. To this output shaft, the movable body 5 is connected, and also a speed detector 6 for sending out a feedback signal, and a resolver 7 used for detecting an absolute position of the movable body 5 are connected to the driving circuit 3. In this regard, a shift data corresponding to a positioned point is outputted by a shift quantity storing ROM10, and a read-out address of the ROM1 is designated by a read-out position shifting circuit 11. In this state, when the movable body 5 reaches the positioned point, the movable body 5 is stopped and positioned at a position where the speed becomes zero, and it becomes unnecessary to reset the movable body 5 to its origin at the time of restart after a service interruption, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positioning device for positioning a movable body in a machine tool or the like.

(Prior Art) Generally, when a movable body such as a rotary table or a feed table of a machine tool is to be positioned with high precision, a numerical control device is used to control the positioning of the movable body. This numerical control device generates a movement command pulse based on movement command data inputted with a paper tape, etc., and a feedback pulse that detects the movement command pulse and the amount of movement of the movable body.
The deviation between the command value and the amount of movement is calculated by calculating the deviation between the two signals and supplying the deviation signal to the servo motor that drives the movable body. The movement of the movable body is controlled so that the value becomes zero.

(Problems to be Solved by the Invention) In the above-mentioned numerical control device, the circuit is complicated because it requires a /-P pulse generation circuit and a deviation counter to generate movement commands and pulses. .

In addition, since positioning is performed by detecting the amount of movement of the movable body, once the power is turned off, such as during a power outage, the memory of the current position of the movable body within the numerical control device is lost, and when restarted, the movable body cannot be moved again. It is necessary to return the body to the original position and reset the memory regarding the current position.

Therefore, the present invention detects the absolute position of the movable body (nt
By performing Et determination control, the circuit can be simplified by eliminating the need for a pulse generation circuit or a deviation counter, and positioning operations can be performed without having to return the movable body to its origin when restarting after a power outage. It has been made possible to do so.

(Means for Solving the Problems) In order to solve the above problems, the present invention adjusts the speed at each position within the movement range of the movable body so that the speed of the movable body becomes zero at a specific position. A single speed/turn to be instructed is stored in memory, and the shift amount and absolute of the movable body corresponding to the deviation between the predetermined positioning point and the position where the speed/two turns above zero is zero. Speed 7 based on position and
! This system shifts the readout position at the motor and drives the movable body by reading out the speed data at that readout position from the memory, which simplifies the circuit by omitting a deviation counter, etc. By detecting the absolute position of the body and controlling its moving speed, it is possible to eliminate the need for the movable body to return to its origin upon restart.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. In FIG. 1, 1 is a single speed for stopping a movable body 5, which will be described later, at a specific position, a speed for storing each turn, and 1.
A 9-turn storage ROM stores velocity data at each position of the movable body 5 in each memory address by associating the movement range of the movable body 5 with all memory addresses, and stops the movable body 5. Zero speed data is stored in a memory address corresponding to a specific position. This R.O.
The speed data read from M1 is input to the motor 4 via the DA converter 2 and the drive circuit 3. A movable body 5 is mechanically connected to the output shaft of the servo motor 4 to drive the movable body 5. In this embodiment, a rotary table is used as the movable body 5. Further, on the output shaft of the servo motor 4, there is a speed detection FA';v6 that detects the moving speed of the movable body 5 and sends a speed feedback signal to the drive circuit 3, and a speed detection FA';v6 that is used to detect the absolute position of the movable body 5. The resolver 7 is mechanically connected. Further, the resolver 7, together with the resolver excitation circuit 8 and the absolute position detection circuit 9, constitutes absolute position detection means. In this absolute position detecting means, the phase difference between the excitation voltage and the output voltage of the servo motor 7 is relative to the rotation angle of the servo motor 40.
, therefore, the output voltage of the resolver 7 and the excitation voltage supplied to the resolver 7 from the resolver excitation circuit 8 are input to the absolute position detection circuit 9, and the absolute position detection circuit 9
detects the absolute position of the movable body 5 by comparing the phases of the pressure waveforms of both chambers, and uses a loop counter containing the detected absolute position of the movable body 5 to correspond to each position with the maximum memory address value of ROM 1 as the upper limit. memory address value (
(digital value) and output. Reference numeral 10 denotes a ROM for storing shift amounts that stores a plurality of shift amounts corresponding to the deviations between a plurality of predetermined positioning points and the position where the speed becomes zero on the speed pattern stored in ROM 1. Shift data indicating the shift amount corresponding to the positioning point designated by the positioning point designation data from is output.

11, as shown in FIG. 3, includes one adder, two adders that receive the output of the adder, and three discriminator circuits, and is opened and closed by the outputs of these discriminator circuits. The memory address corresponding to the absolute position of the movable body 5 from the absolute position detection circuit 9 is included as will be described in detail later. ([ROM] Shifts the read position at the speed and turn stored in ROM 1 based on the 7 data corresponding to the specified positioning point from 0 and stores it in the ROM.
This is a read position shift circuit that specifies a read address of 1.

Next, the operation of the non-embodiment will be explained. In the above configuration,
ROM for speed pattern storage] has τ shown in Fig. 2.
All memory addresses N1~N2m are the moving range 00~ with the reference point of the movable body 50, which is a rotary table, being 00.
Corresponding to 360°, memory address Nm corresponding to 180° contains zero speed data N1 to N1 to instruct stop.
Positive speed data instructing forward rotation are stored in each memory address m-, and negative speed data instructing reverse rotation are stored in each memory address 8m+1 to N2m, respectively, depending on the heavy pressure to be supplied to the servo motor 4. It is remembered for the corresponding denotaruki. In this speed pattern, the speed data at each memory address is set so that the movable body 5 gradually decreases in speed and stops before and after the position where it should stop from a predetermined speed. Now, when one of the plurality of predetermined positioning points is selected by external positioning point designation data, the ROM for storing the shift amount is
The shift amount corresponding to the positioning point stored in 10 is read out.

Here, when the soft amount is v and the positioning point is vn (vn is the angle from the reference point), the shift amount Vn is determined from the relationship with the speed pattern stored in the ROM 1 according to the following equation.

Furthermore, as is clear from the above equation, this shift amount V is R
It is set with a value corresponding to the memory address of OM1. On the other hand, the absolute position detection circuit 9 detects the absolute position of the movable body 5, converts it into a memory address value of N-N2m corresponding to the absolute position, and outputs this as an output P. Next, the above shift amount vn and the output P of the ground position detection circuit 9 are supplied to the readout position shift circuit 1, and as shown in the third factor, the two are first added, and then the added value is P+
Whether Vn is within the range of 0 to N2m or smaller than 0,
N2m J:') is determined, and if p+v is within the range of 0-N2m, the first gate G1 is selectively opened and p+v is output as the read address N.
1x
If P+V is less than or equal to O, the 20th gate G2 is selectively opened and the value obtained by adding N2m to P+vn is output as the read address Nx, and if p-1-vn is greater than or equal to N2rn, the third gate G3 is opened. selectively opens from P+vn to N
The read address NX output from the read position shift circuit 11 is the output of the absolute position detection circuit 9 in the speed pattern of the K ROM 1 as shown in FIG. The memory address specified by P is moved by the number of addresses (shift amount ■n) corresponding to the deviation between the positioning point θ and the stop position in this speed pattern, and the ROM 1 is moved according to this successive address Nx. Absolute position detection circuit 9
When the output P of becomes Nrll-Vn, the read address N
When x becomes Nm, the movable body 5 is stopped. The speed pattern in the ROM 1, which is set so that the movable body 5 will stop at a position of 180°, can be used as the speed/setan for stopping the movable body 5 at a predetermined positioning point θ. During a turn, the stop position is set at the center of the moving range of the movable body 5, so the movable body 5 is always set at the predetermined positioning point θ in a short distance. can be moved to

Here, in this embodiment, θ1. as shown in FIG. θ
2 (180°) and θ3 as positioning points, respectively, from the reference point to θ1. Movable body 5 in the order of θ2°θ3
The operation for positioning will be explained. In addition, the fifth
In the figure, clockwise rotation is normal rotation. First, a ROM 10180-θ for storing shift amount.

For each positioning point, the shift amounts V l and V 2 (0) given by the general formula of v=36o×N2m described above are given for each positioning point.
and v3 are respectively stored. Further, the output P of the absolute position detection circuit 9 is output from the movable body 5 as shown in FIG.
is at each positioning point, respectively NUl.

They become Na2 (Nrll) and Na3. Then, the ROM 10K positioning point θ1. When θ21 or 03 is specified, the read position shift circuit 11 shifts the absolute position detection circuit 9 as described above.
Shift amount Vl, V2 or v3 is added to the output P of , and the read address N is outputted by shifting the absolute position of the movable body 5 by a predetermined shift amount.
Accordingly, the speed data stored in the ROM 1 at the speed control point is read out and the movable body 5 is made to move, but once the shift l'iAI Vn is determined, the speed instructed at each position of the movable body 5 is determined. Therefore, in Fig. 6 (b), (C), and (d), move at a speed of 7 turns according to the nof h5'Hvn as shown in Fig. 6 (b), (C), and (d). The operation will be explained by associating the speed pattern with the output P of the absolute position detection circuit 9 when θ and θ3 are specified. First, when the positioning point θ] is specified from the outside while the movable body 5 is at the reference point, , since the output P of the absolute position detection circuit 9 is N1, as shown in FIG. 6(b)
The movable body 5 starts forward rotation according to the speed/mother turn shown in FIG.

Then, as the movable body 5 moves, N2. N3. N4・
The Iffi-order velocity data is read out by the output P of the absolute position detection circuit 9 which changes as ..., and when the movable body 5 reaches the positioning point θ1 and the output P of the absolute position detection circuit 9 becomes Nθ. , the movable body 5 is instructed to have a speed of zero, and the movable body 5 stops. Next, when positioning point θ3 is specified,
The movable body 5 moves according to the speed and turn shown in FIG. 6(d). At this time, the output P of the absolute position detection circuit 11
is NO1, the movable body 5v'i starts reverse rotation with negative speed data that instructs reverse rotation at a predetermined speed, moves to positioning point θ3 in the same way as at positioning point θ1, and moves to positioning point θ3 at the absolute speed. It is positioned at the position where the output P of the position detection circuit 11 is NO3. Next, positioning point θ2 (18
0°) is specified, the shift amount v2 is zero, so
As shown in FIG. 6(c), the movable body 5 is in a state where the speed and 4 turns stored in the ROM 1 in advance are directly read out by the output P of the absolute position detection circuit 9, and the output P at this time is
is NO3, the movable body 5 starts reverse rotation according to the speed data instructing reverse rotation at a predetermined speed, moves to the positioning point θ2, and is positioned there. In the above embodiment, the speed no. (ROM for memory)
The speed noso turn stored in 1 is set to 00~
Although it is set so that it corresponds to each position of 360° and the speed becomes zero at the 180° position, this speed/-1' turn only needs to correspond to each position within the movement range of the movable body 5. ,
Further, the position where the speed becomes zero can also be set arbitrarily.

Also, ROM 1 for speed) and turn memory and shift 1. ；°1. The ROMs 10 for 1 and 2 may each be Rfi-Ms with battery backup.

Furthermore, the ROM 10 for storing the shift amount is not provided, and /7
The data may be directly supplied from outside.

Furthermore, although a rotary table is used as the movable body 5, a linear table may also be used. A single speed/mother turn for instructing the speed at each position within the moving range of the movable body is stored in memory, and the speed/mother turn is stored in memory at a predetermined positioning point and speed/turn.
Shift the proverbial position in the number of speed turns based on the shift amount corresponding to the deviation from the position where the speed becomes zero after 4 turns and the absolute position of the movable body, and read the speed data at the read position from the memory. This device is designed to read data and drive a movable body.The absolute position of the movable body is detected, the absolute position is moved by the above shift amount, and the readout position is specified, and the readout position is set at a preset speed and turn. Move the movable body while sequentially instructing the speed of the movable body at
When the movable body reaches the positioning point, the read position becomes the position where the speed and the speed in one turn are the highest, instructing the movable body to zero speed, and the movable body is stopped and positioning is performed, so it can be used after a power outage, etc. There is no need to return the movable body to its origin when restarting the system, and positioning control can be restarted in the same state. It also has the effect of simplifying the circuit because it eliminates the need for a deviation counter, etc. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an Oma-1 construction according to an embodiment of the present invention, FIG. 2 is a diagram showing a speed pattern according to an embodiment of the present invention, and FIG. 3 is a diagram showing an embodiment of the present invention. Figures 4 and 5 are professional diagrams showing the configuration of the read position shift circuit in
6 and 6 are diagrams for explaining the operation of an embodiment of the present invention, respectively.

Claims (1)

[Claims] In a device that controls a driving means for driving a movable body so that the movable body moves at a specified speed to a specified position, the speed of the movable body becomes zero at a specific position. A memory that stores a single speed pattern for instructing the speed at each position within the movement range of the movable body, and a deviation between a predetermined positioning point and a position on the speed pattern where the speed is zero. a shift amount supply means for supplying a shift amount corresponding to the shift amount; an absolute position detection means for detecting the absolute position of a movable body; and a shift amount supplied from the shift amount supply means and a movable body detected by the absolute position detection means. readout position shifting means for shifting the readout position in the speed pattern based on the absolute position of the speed pattern; and means for instructing the drive means to determine the speed at the readout position on the speed pattern determined by the readout position shift means. A positioning device characterized by comprising: