JPS6043523B2 - High precision trajectory control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention operates along the surface of a three-dimensional base material rotating around a rotation axis, and performs marking, wrapping, welding, and cutting of a linear member on the surface of the rotating base material. , relates to a device for accurately positioning a work tool for cutting or other work.

Conventionally, when performing some kind of processing along the surface of a base material using a work tool, the base material to be processed is rotated, and its axis of rotation is moved laterally in the axial direction. Moreover, methods are used in which the work tool is fixed in the axial direction of the base material, or the work tool is rotated at a fixed position and the work tool is moved laterally in the direction of the rotational axis of the rotating base material. In this case, the ratio of the lateral movement speed to the rotational speed of the rotating body is determined either by connecting the rotational axis of the rotating body and the lateral movement axis by gears and changing this gear ratio, or by driving with an electric pulse command. Digital operating devices (eg, stepping motors) are attached to the rotating shaft and lateral movement shaft of the rotating body, and adjustments are made by changing the pulse ratio between the two.

Therefore, it is not a problem when performing a simple process such as machining a spiral shape on the surface of a cylindrical base material, but the ratio of the rotational speed of the base material to the lateral movement speed is Special care must be taken to ensure accurate and continuous positioning of the implement at all times when the workpiece changes as a function of the angle (0) or when the shape of the workpiece has a shape other than a cylinder, e.g. spherical or other shapes. Computational control, which requires complex machining programs such as those normally found in NC machine tools, has been required. In order to satisfy the above-mentioned requirements, the present applicants have previously determined that the shape of the base material to be rotated and the content of the work have been determined, but when a wide range of settings is required for the coefficient of the work content, and when the base material We have proposed a high-precision work device that can accurately and continuously position a work tool even when a wide setting range is required for the dimensions of the workpiece. Figure 1 is an overall configuration diagram of the working device. In this figure, the base material is rotated and moved in the axial direction, and the work tool is moved back and forth and rotated relative to the base material while attaching the wire member to the base material. An example of wrapping is shown below. In the figure,
A straight rail 2 is installed on a suitable fixed base 1, and a carriage 3 is placed on the rail 2. A ball nut 4 is attached to the reciprocating table 3, and a ball screw 5 installed parallel to the rail 2 is screwed into the ball nut 4. baud. The screw 5 is rotated by a stepping motor 6, so that the carriage 3 runs on the rail 2. Shuttle 3
A base material 8 is installed above, which is supported at both ends by bearings installed on the carriage and rotated by a stepping motor 7 at one end! ing. On the other hand, at a spatial position facing the base material 8, there is provided an extendable arm 9 that moves in a direction perpendicular to the rotation axis of the base material. Ru. A rotary arm 12 is engaged with the telescopic arm 9 and rotates around the tip of the telescopic arm. The rotating arm 12 is turned by a stepping motor 13, and a working tool 14 is fixed to the tip of the rotating arm 12. In the case of Fig. 1, the work tool 14
is a yarn feeding member, from which the filament member 15 is fed out and wound around the base material 8. Note that 16 is a support member that appropriately supports the telescopic arm and the like. The outline of the operation of this work device is as follows: a rotating body (base material) 8 is rotated by a stepping motor 7; A pivoting motion is taken into account to move the implement through a defined path on the surface of the base material 8 to obtain the desired winding.

To operate the tool 14 through a defined path on the surface of the base material 8, the rotation angle θ of the base material 8 is taken as an independent variable, and the coordinates of the tool 14 along the surface of the base material (X ,y
, z). The coordinates (X, y, z) are the positions of three types of dependent axes, namely the position (z) of the carriage 3, the position of the rotating arm 1
The turning angle of 2 (ε-in and the telescopic position (g) of the telescopic arm 9) is expressed as the dependent variables f(0), g(0) and h(
θ). By positioning each control axis in this way, the position of the work tool 14 is fixed. In FIG. 1, 17 is an arithmetic circuit 19, 2 that satisfies the above functional formula.
This is a digital differential analyzer (DDA) that has built-in 0 and 21 and features incremental calculations. A digital signal that commands the rotation angle (0) is obtained by the base material rotation pulse generator 18, and its output is sent to the stepping motor 7 for rotating the base material 8 and the calculation circuits 19, 20, 21 that calculate the position of each dependent axis. supplied to The calculation circuit 19 calculates the carriage position z=f(0), and the calculation output is supplied to the reciprocating stepping motor 6 of the carriage 3. Similarly, in the arithmetic circuit 20, the rotating arm turning angle ε=g(0)
The arithmetic circuit 21 calculates the telescopic arm position 1=h(θ
) are performed, and their outputs are supplied to the stepping motor 13 for turning the rotary arm 12 and the stepping motor 11 for extending and retracting the telescopic arm 9. Arithmetic circuit 19,
Various constants, initial conditions, etc. required in 20 and 21 are given from the operation panel 22. In this way, the digital differential analyzer 17 supplies the angle command (pulse signal) of the base material 8 to the main shaft stepping motor 7, and also calculates the position Z of each subordinate shaft corresponding to one step of the main shaft stepping motor.
, ε, l, and calculate the corresponding dependent axis stepping motor 6,
By driving 13 and 11, each control axis is positioned with high accuracy and continuously. In this),
An outline of a DDA integrator, which is a basic component of a digital differential analyzer, will be explained with reference to FIG.

As is well known, the integration principle of the DDA integrator is the piecewise quadrature method, and the integrand input Y shown in FIG. Diagram b
(7) Stored in the Y register 27. The product Yn·ΔX of this Yn and the independent variable Δx is added to the contents of the R register 26, and the integral value ΣYn·ΔX is stored in the R register 26. The contents ΣYn·Δx of the R register 26 are quantized by a quantizer 28 to become a quantized pulse ΔZ. Therefore, by counting this pulse ΔZ, the integral value (F
Ydx) can be obtained. Note that 23 is a gate circuit, and 24 and 25 are adders. In this way, the DDA integrator, which is the basic component of a digital differential analyzer, is
Its integration principle is the piecewise quadrature method. For this reason, the first
In the working device shown in the figure, the coordinates (X, y, z
) is determined as a function of the rotation angle θ of the base material 8, and when the functional expression is repeatedly solved by the digital differential analyzer 17, errors gradually accumulate and control accuracy deteriorates. In other words, even if it is attempted to control the working tool 14 so that it repeatedly passes the same trajectory along the base material 8, the actual trajectory of the working tool 14 will gradually deviate. The present invention was developed in view of the above-mentioned circumstances, and when controlling a work tool that operates along a rotating base material so that it repeatedly passes the same trajectory, its functional formula can be calculated using a digital differential analyzer. When solving repeatedly, each time the arithmetic circuit is switched in response to the position of the work tool moving from the cylindrical part of the base material to the spherical part (generally a curved part) or from the spherical part to the cylindrical part, the corresponding DDA calculation register is changed. It is an object of the present invention to provide a high-precision trajectory control device that performs initial settings to reduce repetitive calculation errors and prevent a decrease in control accuracy.

Hereinafter, the content of the present invention will be explained in detail with reference to Examples.

FIG. 3 shows an embodiment of the present invention in which the present invention is applied to the arithmetic circuit 19 of FIG.

In the figure, 18 is the rotation angle (
30 is a spherical part calculation circuit which calculates the position of the carriage in the spherical part area of the base material 8;
31 is a cylindrical part calculation circuit that calculates the carriage position in the cylindrical area of the base material 8; 32 is a register that stores the initial value of the spherical part calculation circuit 30; and 33 is a register that stores the initial value of the cylindrical part calculation circuit 31. Registers 34, 36, 43, and 45 are monostable circuits, 35, 44 are timers, 37, 38, 40, and 41 are AND gates, and 39, 42 are OR gates. Now, when the winding operation enters the spherical region of the base material 8 and the spherical section calculation signal becomes high level, the AND gate 38 opens and the calculation pulse (θ) of the base material rotation pulse generator 18 changes to the AND gate 3.
8 and is input to the spherical section calculation circuit 30 via the OR gate 39. The spherical part calculation circuit 30 calculates the carriage position in the spherical part area based on this calculation pulse,
Sequentially, the calculation result Z is transferred to the stepping motor 6 in FIG.
Output to. On the other hand, as the spherical part calculation signal becomes high level, the monostable circuit 45 operates, and its output pulse resets all the registers of the cylindrical part calculation circuit 31 to zero. Around this time, the timer 44 is activated by the spherical part calculation signal.
starts operating, and monostable circuit 4 is activated by the time-up signal.
3 is energized. As a result, the output pulse AND gate 40 of the monostable circuit 43 opens, and the contents of the register 33 are transferred to the cylindrical part arithmetic circuit 3 via the AND gate 40 and the OR gate 42.
Written to 1. That is, the cylindrical portion calculation circuit 31 is initialized. As the winding work progresses and the winding moves out of the spherical region and enters the cylindrical region, the cylindrical region calculation signal switches to high level and the spherical region calculation signal switches to low level. As a result, the calculation pulse (0) of the base material rotation pulse generator 18 is
1. The data is taken into the cylindrical section calculation circuit 31 via the OR gate 42, and the calculation of the position of the carriage in the cylindrical section area is executed.
During this time, the spherical part calculation circuit 30 is reset by the output of the monostable circuit 34 energized by the cylindrical part calculation signal, and then
After a predetermined period of time has elapsed, the timer 35 and monostable circuit 36
The contents of register 32 are AND gate 37 and OR gate 3
9 and initial settings are performed. Thereafter, as the winding work progresses, the above-mentioned operation will be repeated each time the spherical part calculation signal and the cylindrical part calculation signal switch between high level and low level. FIG. 3 shows an example in which the present invention is applied to a system in which the arithmetic circuit is divided into two parts, such as a spherical part arithmetic circuit and a cylindrical part arithmetic circuit, and they are used by switching them alternately. This is just one example, and can generally be applied to cases in which a plurality of arithmetic circuits are switched between each other to repeatedly execute a desired operation. As is clear from the above description, according to the present invention, each time the arithmetic circuit is switched in response to the work tool passing through a shape change point of the base material, the DDA operation register of the corresponding arithmetic circuit is initialized.
Errors do not accumulate over time, and each repetitive work process can be performed under the same conditions, which is expected to further improve control accuracy. In addition, since the initial setting is automatically performed when switching the arithmetic circuit as the work tool passes through a shape change point of the base material, the continuity of the work process is not impaired.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of a working device to which the present invention is applied, FIG. 2 is a principle diagram of a DDA integrator, and FIG. 3 is a block diagram of an embodiment of the present invention. 3... Carriage table, 6, 7, 11, 13... Stepping motor, 8... Rotating base material, 17... Digital differential analyzer (DDA), 18... Base material rotation pulse generator , 19, 20, 21, 30, 31... arithmetic circuit, 32
, 33... Initial value setting register.

Claims (1)

[Claims] 1 A base material having a cylindrical portion and a curved surface portion other than the cylinder, and a working tool disposed facing the base material and working along the base material, and a pulse for commanding the rotation angle of the base material. The base material is rotated by a first digital operation device driven by the output pulses of the generator, and the output pulses of the pulse generator are inputted to a digital differential analyzer having first and second arithmetic circuits. The first and second calculations are performed using the rotation angle of the base material as an independent variable, and the position of the dependent axis that determines the coordinates of the working tool for each of the cylindrical portion and other curved surface portions as a function of the rotation angle. each of which is determined by a circuit, the determined functions are output from the digital differential analyzer in the form of a digital signal, and the working implement is moved by a second digital operating device driven by the output of the digital differential analyzer; In the trajectory control device that controls the work tool so as to repeatedly pass the same trajectory along the base material, an initial value that stores initial values required for calculations of the first and second calculation circuits of the digital differential analyzer is provided. and a value storage means, each time the position of the work tool changes from the cylindrical part to the curved part of the base material, or from the curved part to the cylindrical part, the corresponding initial value of the initial value storage means is stored in the digital differential analyzer. A high-precision trajectory control device comprising: control means for initializing a calculation register in a first or second calculation circuit.