JPH0337701A - Method and device for robot control - Google Patents

Abstract

PURPOSE:To improve the operability and the safety of a robot by outputting a command signal corresponding to a preliminarily set management level to control the robot operation at the time of detecting that the hand position enters into an operation designation area. CONSTITUTION:When an operator sets operation designation areas, a coordinate transformation matrix determined by the structure of a robot 14 in accordance with joint angles of arms 14-1 to 14-n fed back from an arm joint angle detector 22 in every sampling period is used to calculate a hand position Peo in a reference coordinate system C0 by an arithmetic unit 23. In the descending order of set management levels 1 to 4 of inputted operation designation areas, the transformation matrix from the reference coordinate system C0 to a working coordinate system C1 and an area condition formula cut off by the set area type are used to detect whether the calculated hand position Peo is included in the area or not by calculation. When entrance to an area is detected, the command signal corresponding to its set management level is sent to a controller 20 to control the robot operation. Thus, the operability and the safety of the robot are improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method and device for controlling a robot, and more specifically, it relates to a method and device for controlling a robot, and more specifically, it relates to a robot control method and device for controlling a robot to an arbitrary position based on a command issued from a robot control device. The present invention relates to a robot control method and device for improving the operability and safety of a robot equipped with a servo control device that can position the hand position.

(Prior Art) For example, when an articulated robot is used to perform a work motion in a designated movement area, an operator must guide the robot's hand to the designated movement area and teach the work trajectory in advance.

Conventionally, when performing this type of teaching, the operator pays sufficient attention to the robot's movable range, the working conditions around the robot, and the position of each workpiece and jig, including the production line. The robot hands are guided and taught to perform the desired work movements by visually making judgments. Furthermore, in the case of positioning teaching that requires precision, the operator enters the robot's operating range and, in some cases, directly guides the robot by holding the robot's hand for teaching.

On the other hand, in the event of an erroneous operation during guidance, normally the operation will not stop unless the stop switch is pressed.

Furthermore, as a method of limiting the motion range of the robot, the rotation range has been set by the angle of each joint axis of the robot arm.

(Problem to be Solved by the Invention) However, according to the conventional robot control method described above, during a teaching operation, the relative relationship between the workpiece placed in the robot's work environment and the robot hand being guided is Positional relationships can only be determined visually.

Additionally, if you want to limit the movement range or set a monitoring area for the robot's hand during teaching guidance or work, the range must be determined based on the angle of each joint, which is not an orthogonal coordinate system that corresponds to the actual work space. This makes it difficult for the operator to confirm. Additionally, there were problems with robot operability, such as the inability to set multiple ranges.

In addition, while guiding the robot hand, there was also a problem in that the robot hand could collide with other objects due to erroneous operation, which could be dangerous and pose a safety risk.

This invention was made in order to eliminate the problems with operability and safety in the conventional robot control method, and it is a method for positioning the hand of the robot to an arbitrary position based on a command. The purpose of the present invention is to provide a control method that improves the operability and safety of a robot equipped with a servo control device.

Further, the present invention aims to provide a robot control device that can appropriately implement such a control method.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the first method (claim (1)) of the robot control method of the present invention basically consists of the steps shown in FIG. Operated according to procedures. In other words, process 1 involves storing in the servo control device the motion specified range input by the operator in the work coordinate system specified based on the reference coordinate system, and detecting the arm joint angle at each sampling period and determining the hand position from the arm joint angle. Process 2 that determines the position; Process 3 that determines whether the robot's hand position is included in the specified motion area at each sampling period; and if it is determined that it is included, take the action set in the specified movement area. Process 4 sends a command according to the level to the servo control device to control the robot's movement, and if it is determined that it is not included, continues the teaching operation or the robot's work movement, and repeats the procedures from Processes 2 to 3. It is characterized by the fact that

Furthermore, the second aspect of the robot control method of the present invention (claim 2)
) is based on the first robot control method, and the motion designation area input by the operator can be rewritten or changed, or multiple motion designation areas can be input, as necessary, using an input device. Each movement specification area is set by inputting area condition variables based on X1Y, Z orthogonal coordinates for each specified work coordinate system by inputting the position and direction centered on the robot's reference coordinate system. Furthermore, there are multiple treatment levels for controlling the robot's motion when entry into each of the designated motion areas is detected, and depending on the treatment level selected and set for each designated motion area, the operator can The system controls the robot's operation by flashing a lamp or giving an audible warning, slowing down the robot's operating speed, and stopping the robot's operation.

Further, as shown in FIG. 2, the robot control device according to the present invention includes a servo control device 10 that positions the hand of the robot to an arbitrary position based on a command, and an input bag W11 that inputs a designated movement area of the robot. an arm joint angle detection device that detects the joint angles of the robot arm every sampling period and inputs the detected robot arm joint angle results to the calculator 13; In addition to calculating the hand position of the robot with respect to the reference coordinate system, it also detects whether the hand position is included in the memorized movement specified area, and based on the detected and calculated results, it issues control commands according to the setting action level of the movement specified area. and an arithmetic unit 13 that sends the information to the drive motor 15 of the robot 14 via the control unit 10.

(Operation) Since the structure is as described above, according to this invention, (
Claims (+), (2) and <3)) The operator can input and set the motion designation area for the work environment as necessary. This operation specification area can be set as an area in the work coordinate system specified based on the reference coordinate system using orthogonal coordinates (x, yr z), so it is easy for the operator to recognize various areas. You can easily enter information using the ``Settings'' button, and you can select from multiple levels of actions to be taken when entry into the set area is detected, allowing you to use them depending on the operation.

Therefore, when performing teaching operations, if you set the movement designated area in advance for each object placed in the work environment at the treatment level of flashing lamps when entering the area, the position of the robot's hand during guidance and each object can be adjusted. Operability is improved because guidance can be given while recognizing the relative positional relationship with objects by blinking lamps. In addition, in the case of positional teaching that requires precision, when the operator enters the robot's movement range or directly guides the robot by holding the hand, it is necessary to set the appropriate operator's position in advance as a movement designated area. By inputting a treatment level that stops the robot operation upon entry, operator safety against erroneous operations can be ensured.

(Example) Next, a robot control device according to the present invention will be explained using the drawings. Since the robot control device of this embodiment is configured to specifically implement the robot control method according to the present invention, the description of this embodiment will be used to explain the first and second methods of the robot control method according to the present invention. This will be replaced with the embodiment of the second invention (claim (1) and claim (2)).

FIG. 3 shows the system configuration of the robot control device of the embodiment, in which 20 is a servo control device, 21 is an input device, 2
2 is an arm joint angle detection device, 23 is a calculation device, 14 is a robot, 14-1.14-2, ... 14-n is a robot arm, 15-1.15-2, ... 15-n
are arms 14-1, 14-2, . . . 14-n, respectively.
It is a motor that drives and operates the

The input device 21 is a device used for inputting a motion program in a robot language, and the teaching operator uses this to input a motion designation area as necessary.

The arithmetic unit 23 stores the input motion designation area, and detects and feeds back the robot arm 14-1.
14-2, ... 14-n Calculates the hand position with respect to the reference coordinate system from each joint angle, and detects at each sampling period whether the hand position is included in each memorized motion specified area. Then, a command signal, for example, a command to flash a warning lamp or generate a warning sound, is sent to the servo control device 20 in accordance with the set treatment level of the detected operation designated area.

FIG. 4 shows an example of the action designation area set using the input device 21.

If the motion designation area to be input is R1, then the reference coordinate system C3 (
The position and direction values (Xc+, Yc+, ZCI, αC1) of the work coordinate system C+ (X+, I+ zl) in the motion specified area R1 for
- Input βCI+γc+). Here, αCI+
βC yo γC1 are the reference coordinate system C6 (Xa
+Yo +Zo) roll, pitch,
Let it represent the yaw angle.

Next, the type of operation designated area R1 is determined in Fig. 5 (a) (b) (
c) Specify from among the four types shown in (d) respectively: planar area type, rectangular parallelepiped area type, cylindrical area type, and spherical area type, and each specified area as shown in Table 1 below. Enter the area condition variable value (second column) corresponding to the type and select area R1.
Determine.

(The following is a blank space) At the same time, the action to be taken when entry into the set area is detected is determined by selecting from the following four action levels.

Level 1: Flash the lamp provided on the control device 2o or teaching device Level 2: Generate a warning sound provided on the control device 20 Level 3: Decrease the operating speed of the robot 14 Level 4: Stop the operation of the robot 14 The settings of this action designation area can be rewritten and changed at any time using the input device 21.

When the operator sets a plurality of specified movement ranges as necessary in the above manner, the arithmetic unit 23 first processes each arm 14 . . . 1 . 14-2,...
Using the coordinate transformation matrix determined from the joint angle of 14-n and the structure of the robot 14, the hand position P in the reference coordinate system co is determined.
, , (X, .+Y*elz0) is calculated. Next, the transformation matrix A from the reference coordinate system to the set work coordinate system in descending order of setting action levels 1 to 4 in the input operation specified area, and the area conditional expression determined by the set area type (
Using equations (1)-(4)), the hand position P obtained previously
,.

Calculate and detect whether or not is included in the area.

For example, assume that the following two action designation areas are set.

Area l Working coordinate system CRI (XRII YRII
ZRIIαR1・βR1・γR1) Planar area type two input variables (kpm, 1□, 0゜all
l b R11O+ 1) Treatment level l area 2
Work coordinate system CR2 (X R2r V R2+ Z R
2+αR2・βR2・γR2) Cylindrical area type two input variables (a R2+ t) R21r
R21G! 121 + CR22) Treatment level P is the hand position with respect to the reference coordinate system C0 calculated by a coordinate transformation matrix determined from the structure of the robot using each arm joint angle of the robot detected every sampling period. (X, , y, , Z, ,), each area 1
．． Hand position P el (XRI
I Y *l+ z*t) l P 112 (XRI
IV*++Z-+) can be calculated using the following formula.

P, 1-A R1-'-p,.

Pay-A R2-'・P.

Here, A11l and βR2 are the reference coordinate system C0 (
The transformation matrices A R+-' and A R2-' from Xa yo Za ) to the work coordinate system CR11CR2 are their inverse matrices, and the variable values (x, y, z,
α.

It can be found from the following equation using β, γ).

However, it shall represent Cα-cosα and Sα-5inα.

When each position of P @1 + P @2 is found, the regions R1, R
From the area type conditional expression (+>, (3) set in 2)
@I+P Detect whether each R3 is a point within the area.

R1: kR+ (X-+ a**)+l*+ (V
at-bRt) >-Q? R2: CI+21
<-Zsz< CR22? (Xa2-βR2)'
+ (yo2-bq2) 2<1111 "R2? In this case, since region R2 has a higher treatment level number than region R1, the detection calculation is performed first.

In this way, detection calculations for each set area are performed by the arithmetic unit 23 at every sampling period, and when entry into a certain area is detected, a command signal corresponding to the set action level 1 to 4 is sent to the control unit 20, and the robot operates. control is performed.

In the above-mentioned embodiment, the commands issued regarding the setting action level of the specified motion range are listed as warning lamp flashing, warning sound generation command, etc., but these are not limited to these commands. The command may also be sent to the control device 20.

[Effects of the Invention] As is clear from the above description, according to the robot control method and device of the present invention, a monitoring area or movement restriction can be set at the robot hand position during teaching operation or work execution according to the operator's needs. The area can be easily set at any position using the orthogonal coordinate system, and when it is detected that the hand position has entered the specified movement area, a command signal is sent according to the preset treatment level. control the robot's movements. Therefore, the operability of the robot is improved, and there is an advantage that safety can be maintained against malfunctions.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing the basic configuration of a robot control method of this invention, FIG. 2 is a system configuration diagram showing the basic configuration of a robot control device of this invention, and FIG. 3 is a robot according to an embodiment of this invention. A schematic configuration diagram of the control device, FIG. 4 is an explanatory diagram showing the method of inputting the operation designated area, and FIGS. 5(a), (b) (
c) and (d) are perspective views showing various shapes of the motion designation area. 10.20...Servo control device 11.21...Input device 13.23...Arithmetic device 12.22...Arm joint angle detector 14.14-1
．． 14-2. ..., 14-n... arm, 15.1
5-1.15-2. ... 15-n...Arm drive motor

Claims (3)

[Claims] (1) In a robot equipped with a servo control device that positions the robot's hand position to an arbitrary position based on a command, the specified motion area input in the work coordinate system specified based on the reference coordinate system through the input device. a process of detecting joint angles of the robot arm at each sampling period and determining the hand position of the robot from the detected arm joint angles; A process that determines whether the robot hand position is included in the memorized movement specified area, and if it is included, sends a command according to the treatment level set in the movement specified area to the control device and controls the robot's movement. If not included, continue the teaching operation or robot work operation, detect the joint angle of the robot arm every sampling period, determine the robot hand position from the detected joint angle, and then continue the teaching operation or robot work operation. A method for controlling a robot, comprising repeatedly performing a process of determining whether the position of the robot's hand during a work operation is included in the storage operation area. (2) In the statement of claim (1), the action designation area that the operator inputs through the input device can be rewritten or changed or input multiple action designation areas by the input device as necessary. , each movement specification area is set by inputting the position and direction centered on the robot's reference coordinates and inputting area condition variables based on the X, Y, and Z orthogonal coordinates for each specified work coordinate system. Furthermore, there are multiple treatment levels for controlling the robot movement when entry into the specified movement area is detected. 1. A method for controlling a robot, comprising: controlling the operation of the robot by flashing a lamp or sounding a warning, decelerating the robot's operating speed, and stopping the robot's operation. (3) A servo control device that positions the robot's hand to an arbitrary position based on commands, an input device that inputs the specified movement area of the robot, and a memory that stores the specified movement area input through the input device, and An arm joint angle detector detects each joint angle of the robot arm and inputs the detected robot arm joint angle value to a calculator, and a In addition to calculating the robot's hand position, it also detects whether the hand position is included in the memorized movement specification area, and based on the obtained results,
A robot control device comprising: an arithmetic device that sends a control command corresponding to a set treatment level of a specified motion region to an arm drive motor of the robot via a servo control device.