JPS62282303A - Controller for industrial robot - Google Patents

Abstract

PURPOSE:To attain the operation with plural coordinate systems changed over by providing a means discriminating a selected coordinate system in response to the switching operation of a selector switch and switching the operating processing mode into the processing mode based on a selected coordinate system. CONSTITUTION:An operation processing unit 1 is provided with an operation processing mode changeover means 1 receiving a '1' or '0' signal generated through the changeover of the selector switch S1 and discriminating the operation coordinate system of a selected robot 5 so as to switch the operation processing mode, an orthogonal coordinate system operation processing means 12 operating the object position or speed of each axis of the robot 5 at each prescribed time interval based on the orthogonal coordinate system according to the changeover of the operating mode and a cylindrical coordinate system operation processing means 13 applying the operation based on the cylindrical coordinate system. The operation result from the operation processing unit 1 is given to servocontrol sections 3, 4 for axes M1, M2 of the robot 5 as the position or speed command via a bus 6.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an industrial robot control device, and particularly to an industrial robot control device using an arithmetic processing unit.

[Conventional technology]

Industrial robots include articulated robots and cylindrical coordinate robots as shown in FIGS. 4 and 5, and the operating range of each robot is fan-shaped when viewed from above the robot. In addition, these robots can move linearly between two points when the position is given, or break down the movement distance (or angle) between the two points into each axis, and each axis moves at a constant speed. It can be broadly divided into those that do

For this reason, conventionally, the mouth 4 +ll which performs a linear movement
In the case of K-Article View ヂResent M Heto λ弗 にや に い い ん ↓, it is impossible to operate due to the restriction of the inner diameter of the operating range, so it is necessary to provide an intermediate target point within the operating range, and A robot that operates at a constant speed for each axis does not have the above-mentioned drawbacks, but has the inconvenience that the movement path is difficult to intuitively understand because the movement is not linear.

Additionally, since each axis has a constant speed, there is a problem that the movement is faster at the outer periphery (the tip of the arm).

[Problem that the invention seeks to solve]

The present invention provides an industrial robot control device that can operate an industrial robot by switching between a plurality of coordinate systems including a Cartesian coordinate system and a cylindrical coordinate system according to the operational limit range and desired operational path of the industrial robot. purpose.

[Means for solving problems]

A servo control unit for each axis that uses an arithmetic processing device to calculate the target position or velocity of each axis at a predetermined time interval of an industrial robot capable of operating in multiple coordinate systems including a rectangular coordinate system and a cylindrical coordinate system. In an industrial robot control device that controls the operation of an industrial robot by giving a coordinate system to a plurality of coordinate systems, a selection switch selects and switches an operating coordinate system of the industrial robot from a plurality of coordinate systems;

means for determining the selected coordinate system and switching the arithmetic processing mode performed by the arithmetic processing device to a processing mode based on the selected coordinate system.

[Effect]

When the selection switch is switched to one of the operating coordinate systems among a plurality of coordinate systems, the operation mode switching means determines the switched operating coordinate system based on the signal generated by this switching, and selects the operation processing mode to be performed by the processing unit. is switched to an arithmetic processing mode based on this motion coordinate system.

〔Example〕

FIG. 1 is a block diagram of an embodiment of an industrial robot control device according to the present invention, and FIG. 2 is a flowchart. A case of operation in two operating coordinate systems, a cylindrical coordinate system, will be described. Note that the robot 5 may be either a conventional joint type or a cylindrical coordinate type. In FIG. 1, an arithmetic processing unit 1 is composed of a microcomputer conventionally used for controlling robots, and an input port 2 is connected to a selection switch S1 for selecting a rectangular coordinate system or a cylindrical coordinate system as the operating coordinate system of the robot 5. connected via. The selection switch Sl is a manual switch such as a rotary switch. For example, when point a is switched to one rectangular coordinate system, a low level "0" signal is generated, and when switched to the other cylindrical coordinate system, a high level rlJ signal is generated. coming out.

The arithmetic processing device 1 receives a "1" or "0" signal generated by switching the selection switch S1, determines the operating coordinate system of the selected robot 5 based on the signal, and has an arithmetic processing mode switching means for switching the arithmetic processing mode. 11), a rectangular coordinate system calculation processing means 12) which calculates the target position or velocity of each axis of the robot 5 at each predetermined time interval based on the rectangular coordinate system according to this switching of the calculation mode, and calculation based on the cylindrical coordinate system. A cylindrical coordinate system calculation processing means 13 is included. Note that this is an omission necessary for controlling the robot 5.

The calculation results from the processing unit 1 are sent to the servo control unit 3 for each axis (Ml, M2) of the robot 5 as a position or speed command.
, 4 via 7<s 6. Servo control section 3
．． Reference numeral 4 compares the given position or speed command with the actually detected position or speed to control the motors, etc. of each axis of the robot 5, and is similar to the conventional one. The operation will be explained with reference to the flowchart in FIG. 2. The operation is started in step 20, and the selection switch S1 is used to select, for example, when the desired movement path of the robot 5 is limited by the inner diameter of the robot's movement range. selects the cylindrical coordinate system as the operating coordinate system, or selects the rectangular coordinate system in the case of a visible operating path within the operating range, and switches the selection switch S1 to the corresponding position. As for the signal S from the selection switch SL, when the rectangular coordinate system is selected, the a line is a low level "O" signal, and when the cylindrical coordinate system is selected, the b line is a low level "0" signal is the input port 2. arithmetic processing mode switching means 1 inputted to the arithmetic processing device 1 from
1, the signal S determines which line is "O", and if the a line is rOJ, the arithmetic processing mode is set to rectangular coordinate system processing mode, and if the b line is rQJ, the calculation processing mode is set to cylindrical coordinate system processing mode. (Step 22).

Note that it is also possible to store the timing of switching the switch in advance in the arithmetic processing device and have the device automatically perform the switching □.

The calculation of the target position P at each predetermined time interval in the rectangular coordinate system calculation processing mode (step 23) is as follows.

In this case, coordinate axes are determined as shown in FIG. Further, for the sake of simplicity, the explanation will be made in two dimensions. If we move from point P+ to P2, point P2 is (XI, ?+) in the orthogonal coordinate system.
), and point P2 is represented by (Xz, Yz).

If we consider the moving distance from point P1 to point P2, then the position P at each predetermined time interval is t P'' (X2 XI, Vz -Y+)+p.

look given as.

Therefore, by calculating the position of point P using this equation and using it as a position command, or calculating the speed from the position of point P and giving it as a speed command to the servo control unit 3.4, each axis of the robot can be set to point P1. A linear movement is performed from the point P2 toward the point P2, and the necessary acceleration/deceleration control and the like are the same as in the conventional case. Now, when the length from the center of rotation to the tip of the arm is ρ, the linear velocity is p,
Since it is given by 8 and this is constant.

ρ, φ=C (C is a constant) -1-(1) Also, since the path cannot be determined only under the condition that the linear velocity is constant, if the speed ρ along ρ is also constant, then ρ=kt+ρ1 (k is a constant) ---(2)(1),
From equation (2), (3) Also, in C/, α is from the boundary condition, therefore, the position of P is determined by using time t as a parameter, Pρ =
kt+ρ, Pφ=-log(kt+pI)+Ctk
given as. In particular, when ρ1=ρ2, Pρ冨ρ1 t Pφ=□+Φ1.

ρ Therefore, by applying Pρ and Pφ as position commands to the servo control section 3.4 at predetermined time intervals, the desired operation can be obtained.

(Effects of the Invention) In the present invention, in a control device for an industrial robot that can operate in a plurality of coordinate systems including a rectangular coordinate system and a cylindrical coordinate system, Accordingly, when the inner diameter is within the range of m, the operation can be performed based on the cylindrical coordinate system, and when the operation path can be clearly seen, the operation can be performed using the orthogonal coordinate system. In the operation of the orthogonal coordinate system, there is no need to increase the number of intermediate/teaching points between operations when the operation path is limited by the inner diameter of the enclosure, and control becomes simple and smooth. In operation, the problem of not being able to operate in a straight line even when the operating path is clearly visible is eliminated.

In the cylindrical coordinate system operation, if the linear velocity of the tip of the arm is controlled to be constant, it is possible to eliminate the problem that the tip of the arm moves farther in conventional control where each axis has a constant speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the industrial robot control device of the present invention, FIG. 2 is a flowchart explaining the operation of the control device in FIG. 1, and FIG. 3 is a flow chart explaining the operation of the control device in FIG. 1. Figures 4 and 5 are schematic diagrams showing the structure and operating range of conventional articulated and cylindrical coordinate robots, and Figures 6 and 7 are rectangular coordinate system motion and cylindrical coordinate system motion. FIG. In the figure, 1-m-processing unit 2-each person 3.4
---Servo control unit 5-m-Robot 11--Arithmetic processing mode switching means 12-m-Cartesian coordinate system arithmetic processing means 13--Cylindrical coordinate system arithmetic processing means S1-m-Selection switch agent Patent attorney Takeo Goto, agent Patent attorney Isao Fujiki, agent Patent attorney Sano 1 Figure 1 1 Destination R device 13 Dutch scale calculation processing means No. 2; 1

Claims (2)

[Claims] (1) By commanding the operation start and operation end positions of each axis of an industrial robot that can operate in multiple coordinate systems including orthogonal coordinate systems and cylindrical coordinate systems, the target position of each axis at predetermined time intervals Alternatively, in an industrial robot control device that controls the motion of an industrial robot by calculating the speed using a processing unit and giving the calculation results to a servo control unit for each axis, the operating coordinate system of the industrial robot is means for selecting and switching among the coordinate systems; and determining the selected coordinate system in response to the switching operation of the means;
An industrial robot control device comprising: means for switching an arithmetic processing mode performed by the arithmetic processing device to an arithmetic processing mode based on the selected coordinate system. (2) In the control device according to claim 1,
When the arithmetic processing mode is switched to the arithmetic processing mode based on the cylindrical coordinate system by the means for switching the arithmetic processing mode, the movement of the tip of the arm of the industrial robot is controlled to a constant linear velocity, except during acceleration and deceleration. Robot control device.