JPH03123908A - Device and method for directly teaching position and attitude of robot - Google Patents

Abstract

PURPOSE:To simplify an operation and to improve work efficiency in direct teaching work by respectively controlling teaching intervals in the case of translation and rotation, and storing teaching data in the teaching point. CONSTITUTION:The arm 2 of a robot 1 is guided while teaching data of the position of the robot 1 or the attitude is continuously taken in and stored for respective teaching points decided by the translation moving intervals which a teaching worker arbitrarily sets or the moving intervals related on the rotation of the attitude of a finger part. At that time, the teaching intervals deciding the teaching points by using a teaching interval setting means 11C at the time of starting teaching work are set to be the moving intervals and a prescribed value is numerically supplied. Thus, a teaching interval operation means 8 judges a moving distance based on position data obtained from the position sensor of the robot 1 based on the teaching intervals, automatically detects the teaching points and stores the position and the attitude of the finger part of the robot at that time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a direct teaching device and direct teaching method for the position and posture of a robot, and in particular to teaching data for teaching playback type robots and working machines. The present invention relates to a device and method for directly teaching the position and posture of a robot, which simplifies reading and storing operations and improves work efficiency.

[Conventional technology]

Conventionally, direct teaching methods for robots based on force control have been proposed. In this direct teaching method, a teaching worker applies force to a hand effector installed at the tip of the robot's arm, and this applied force is detected by a force sensor installed in the wrist.
Based on the force signal output by the force sensor and according to a control means that performs upward force control according to a predetermined calculation formula, the movement of the robot's arm is controlled to move in the direction of the applied force, and the hand effector is controlled. The moving speed and direction are determined, the hand effector is guided to the target position, and the teaching data is stored. In controlling a robot using this force control, force is applied to the robot arm to guide it, position the hand effector at the tip of the arm to the target position (including the posture), and then position it at that positioning point. The teaching data of the position and attitude were memorized, and the teaching data was stored for each positioning point. Another method of obtaining teaching data is the direct teaching method in which teaching is performed with the power unit of the robot or work machine inactive, and the interval between teaching data reading points is set to the cycle time of the controller, for example. There is a method that stores teaching data according to a fixed time interval determined by using a method such as a fixed time interval.

[Problem to be solved by the invention]

In the above-mentioned conventional direct teaching method, according to the method of determining the point at which the teaching data is read point by point and storing the teaching data, for example, in a work such as tracing along the surface of a workpiece with a complicated shape, A large number of teaching points are set along the workpiece, and the position and orientation must be taught at a large number of teaching points, which has the drawback of requiring a great deal of time and effort.

Furthermore, in the conventional method in which the teaching interval is set based on temporal timing, the time of the teaching point is determined, so strict time management is required in the teaching work. Furthermore, there is a problem in that the number of teaching data is determined depending on the time required for the entire teaching work, and the number of teaching data varies depending on the work. Furthermore, if the robot is kept in a stopped state during teaching work, the teaching data storage time is determined by a fixed time interval, so data in the stopped state will be stored without limit. Therefore, in a teaching task in which memorization is performed at a temporal timing, the teaching action of the teaching worker is very important, and the teaching task requires great tension, which has the disadvantage that the task cannot be performed easily.

In view of the above-mentioned conventional problems, an object of the present invention is to provide a structure in which the teaching data acquisition point can be set at a predetermined translation and rotation movement distance in direct teaching work of the position and posture of a robot by force control. It is an object of the present invention to provide a direct teaching device and a direct teaching method for the position and posture of a robot, which are intended to simplify operations and improve work efficiency in direct teaching work.

[Means to solve the problem]

The direct teaching device for the position and posture of a robot according to the present invention includes:
A force sensor is provided at the wrist of the arm to which the hand effector is attached, and the force signal output from this sensor is input to the control means, and the arm is guided according to force control based on the force signal, and the arm is guided at an appropriate teaching interval. In a direct teaching device for the position and posture of a robot configured to retrieve the position and posture of a robot's hand at a plurality of teaching points via a position sensor and a position detection means and store it in a storage means, the teaching interval is moved. A teaching interval setting means for arbitrarily setting an interval, and a robot that stores the set teaching interval and manually moves the robot using position data extracted by a position detecting means from output signals of position sensors arranged in each part of the robot. and a teaching interval calculation means for calculating a distance, comparing the moving distance with a stored teaching interval, and storing teaching data of the position and posture of the robot in a storage means at teaching points for each teaching interval. configured.

The method for directly teaching the position and posture of a robot according to the present invention is as follows:
In the direct teaching method of the mouth pot, the teaching worker applies a force to the force sensor of the arm, and at this time, the arm is guided according to single-force control based on the force signal output by the force sensor to perform teaching work. However, the teaching data of either the robot's position or posture is continuously and automatically captured for each teaching point determined by either the translation interval set arbitrarily by the teaching worker or the movement interval related to the rotation of the hand posture. It is characterized by being memorized.

[Effect]

In the above-mentioned direct teaching device for the position and posture of the robot, when starting the teaching work, the teaching interval for determining the teaching point can be numerically given a fixed value as the movement interval using the teaching interval setting means, and this When the interval is given, the teaching interval calculation means determines the moving distance based on the position data obtained from the robot's position sensor based on the teaching interval, automatically finds the teaching point, and calculates the teaching point of the robot's hand at that point. In the above-mentioned direct teaching method of the robot's position and orientation in which the position and orientation are stored in a storage means, the teaching operator determines the teaching point according to the content of the work and the work situation, and the teaching interval is used as the translational and rotational movement interval. It can be given arbitrarily, and after setting the teaching interval, the teaching interval is automatically checked, the teaching point is determined, and the teaching data is stored.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of a robot system to which the present invention is applied. In FIG. 1, 1 is a robot body, and an arm 2 having multiple joints is attached to a support base 3.
Due to the movable action of each joint of the arm 2, the tip of the arm moves to a desired position, and the entire arm changes to a desired posture.

A six-axis force sensor 5 is attached to the wrist portion 4 located at the tip of the arm 2, and a workpiece 6 is attached to the tip of the force sensor 5.
A hand effector 7 is attached to perform work on the robot.

Reference numeral 8 denotes a controller, and the controller 8 includes a control means composed of a computer or the like, and controls the robot 1 by using a predetermined calculation formula for force control and according to a predetermined procedure. It has the functions to execute.

The controllers 8 are electrically connected to each other so as to provide a command signal 9 for instructing the robot 1 to operate, and to receive a detection signal related to the force applied to the force sensor from the force sensor 5, that is, a force signal 10. There is. Reference numeral 11 denotes a teaching box owned by a worker who teaches, and is provided with a numeric keypad and a plurality of operation switches that can give various commands to the controller 8. Among the operation switches, the teaching box according to the present embodiment includes a switch 11A10 for directly calling the teaching routine, a switch 11B1 for teaching the position and posture of the arm tip, and a teaching interval setting switch for setting the teaching interval. 11C is provided. The teaching box 11 is connected to the controller 8, and data given to the teaching box 11 by an operator's operation is given to the controller 8.

The specific configuration of the control mechanism by the controller 8 will be explained based on FIG. 2. The direct teaching device according to the present invention is realized using a computer included in the controller 8, and the device configuration shown in FIG. 2 is substantially shown as a functional block diagram.

As shown in FIG. 2, within the controller 8, a force detection section 12, a force component coordinate conversion section 13, a speed calculation section 14, and a coordinate conversion section 15 are provided as functional means. These functional means are such that when a teaching worker applies a force to the hand effector 7 of the robot 1 for the purpose of teaching, the force is detected by the force sensor 5 and the hand of the robot 1 is transmitted in the direction of the applied force. This is a configuration of a control device for operating the effector 7. The operation mode of the arm of the robot 1 is determined by a calculation formula for force control set in the speed calculation section 14.

In the above configuration, the force detection section 12 receives the force signal output from the force sensor 5, and detects the operating force applied by the operator to the arm 2 of the robot 1 for guidance. Information regarding the detected operating force is supplied to the force component coordinate conversion unit 13, where it is converted into an orthogonal coordinate in the hand coordinate system provided on the wrist part 4 of the arm 2 of the robot 1 or in the base coordinate system with the robot body as a reference. Convert to axial force and moment around the axis in three axial directions. Based on the forces and moments obtained in this way, the speed calculation section 14 obtains speed command values for the motors provided at each joint in the robot 1. Specifically, the following calculation formula is set in the speed calculation unit 14, for example.

i: Speed command value for translation in the i-axis direction of the mini base system fi: i-axis direction component of the operating force M: virtual mass C: virtual viscous damping coefficient In the above equation, given by the force component coordinate conversion unit 13 using the data fi and fixed values M and C (however,
(Both values can be changed freely as needed)
The speed command value of the orthogonal coordinate system is calculated for each axis using The speed command values obtained in this way are converted into speed command values for the motors of each joint of the robot 1 by the coordinate conversion unit 15, and each motor is driven.

Further, the controller 8 is provided with a position detection section 16 and a teaching data storage section 17. The position detection unit 16 inputs output signals from position sensors (not shown) disposed in each part of the robot 1, reads position data and posture data from the input position signals under predetermined conditions, and detects each specified position. It has a function of sending data on the position and posture of the robot 1 at the teaching point to the teaching data storage section 17. Reference numeral 18 denotes a movement interval calculation section, and this movement interval calculation section 18 provides conditions for storing position data etc. obtained by the position detection section 16 in the teaching data storage section 16, as will be described later.

Next, the relationship with the teaching box 11 will be explained. When performing direct teaching work for the robot 1, the operator presses the operation switch IIA to call up the direct teaching routine. This allows the operator to perform teaching work by applying force to the hand effector 7 of the robot 1. The force applied to the hand effector 7 by the worker is sent to the force detection section 12. Further, the storage operation in the teaching data storage section 17 is performed by turning on the teaching switch 11B provided on the teaching box 11. Further, the teaching data acquisition time point is specified by the teaching interval setting switch 11C. By operating the teaching interval setting switch 11C, it is possible to arbitrarily set the translational movement distance Δ1 in the case of a translational movement and the rotational movement angle Δθ in the case of a rotational movement. Numerical values can be input using one method from the menu, or
In fact, it is also possible to input each time using the numeric keypad of the teaching box 11. The output signal of the teaching switch 11B and the output signal of the teaching interval setting switch 11C are given to the above-mentioned movement interval calculating section 18.

In such a configuration, the movement interval calculation section 18 inputs the position information and posture information detected by the position detection section 16, and calculates this (
S)4i! The distance traveled by the hand portion of the robot 1 and the rotational angle of the wrist portion 4 are calculated based on information, etc., and one of these calculated values is the translational movement set in advance by the teaching interval setting switch 11C. When the distance Δ11 or rotational movement angle Δθ is exceeded, a storage command signal is sent to the teaching data storage unit 16 to automatically store the teaching data of the position and posture of the robot 1 output from the position detection unit 17. issue. In addition, the teaching data storage operation is performed using the teaching switch I so as not to store unnecessary data.
It is programmed to be valid only when IB is on.

Next, the operation of the direct teaching device and the direct teaching method according to this embodiment will be explained according to the flowchart of FIG. A program that implements this flowchart is prepared in the controller 8.

First, in step 19, a teaching interval is set. This setting is performed by operating the teaching interval setting switch 11C on the teaching box 11. As the teaching interval, a movement distance Δl is set in the case of translation, and a rotational movement angle Δθ is set in the case of rotation of the wrist part.

Note that the setting value of the teaching interval can also be set internally in advance. In the next judgment step 20, it is judged whether or not the teaching work should be completed. If the process should not end, the process moves to step 21, and the state of the teaching switch 11B is determined. When the teaching switch 11B is in the on state, a teaching operation is performed, the position detection unit 17 detects data on the current position and posture of the arm end of the robot 1, and the teaching data is stored in the teaching data storage unit 16. Store (step 22). Next, in step 22, the data of the current position and current posture of the arm tip of the robot 1, which were stored as teaching data, are set as reference position data, and the reference position data is set to P. , posture data is Q.

It is closed and set (step 23). This reference position becomes the starting point position for calculating the movement interval for the next movement of the robot 1. Next, in step 24, a program for moving the robot 1 is executed to move the robot 1. This movement is a movement of the tip of the arm 2 based on force control, and means movement of the tip of the arm by guidance of the arm by the teaching worker.

In the flowchart shown in Fig. 3, the routine for movement is shown in the same control loop to make it easier to understand the procedure for detecting the position of the moving robot, but the movement of robot 1 is performed in a separate control loop. It can also be executed.

Next, the current position of the moving robot 1 is detected at each predetermined cycle as position data Pi1 and posture data Qi by the position detection unit 17 (step 25). The movement interval calculation unit 18 calculates the movement interval of the robot by using the previously set reference position (Po, Qo) and the currently input current position (Pi, Qi) data, and calculates the difference between the two data (
Step 26) The calculated values obtained at this time are such that the difference due to the translational movement is the translational movement interval P, and the difference due to the rotational movement is the rotational movement amount ΔQ. Here, teach switch 11B again
is on (step 27). If the teaching switch 11B remains on, the translational movement amount ΔP
and the translational movement interval Δl, and also compare the rotational movement amount ΔQ and the rotational teaching interval Δθ, and if the conditions of Δl≦ΔP or Δθ≦ΔQ are satisfied, the process proceeds to step 22 and the hand portion of the robot 1 is The current position of is detected and the position and orientation teaching data are stored, and then the above steps from step 23 onwards are repeated (step 28). Step 28
If the conditions in are not satisfied, move step 2
4, the next movement routine is executed, and then steps 25 to 28 are repeated.

In step 27, if it is determined that the teaching switch IIB is off, the current position of the robot 1 is detected via the position detection unit 16, and this is stored as teaching data in the teaching data storage unit 17 (step 29). Thereafter, the process moves to step 30 for executing a movement routine, and returns to step 20 for determining the teaching work. If it is determined in step 20 that the teaching work has ended, the teaching work ends. Incidentally, even when the condition is not satisfied in step 21, the process moves to step 30. The direct teaching method according to the present invention is executed by the above procedure.

FIG. 4 shows an example of a work using the direct teaching method according to the present invention, and this work is a work in which a hand effector 7, which is a tool, is made to follow a workpiece 6'. In FIG. 4, the hand effector 7 is guided to a starting point A for tracing the workpiece 6', and at this starting point A, the teaching switch 11B is turned on. At this time, as explained in steps 21 and 22 of the flowchart, the teaching data regarding the position and posture of the hand effector 7 of the robot 1 at the starting point A is stored in the teaching storage section 16. Next, when the teaching operator guides the hand effector 7 along the workpiece 6', the teaching interval Δl preset by the teaching interval setting switch 11C is changed in step 19.
The teaching data of the position and posture of the hand effector 7 is automatically stored for each Δθ (in the case of translation) or Δθ (in the case of rotation). Control for this part of the direct teaching work is executed by steps 22 to 28 described above. Finally, when the teaching switch 11B is turned off when the hand effector 7 is guided to the end point B of copying the workpiece 6', the teaching data of the position and posture at the end point B are stored (corresponding to step 29).

Although FIG. 4 describes an example of the execution of the direct teaching work of the hand effector 7 in two dimensions, the same method is used when moving a three-dimensional work in a three-dimensional manner.

As described above, the teaching interval is managed by the moving distance in the case of translation, and by the rotation angle in the case of rotation.
By automatically determining a teaching point and storing the teaching data at that teaching point, the robot can be taught simply by moving the tool along the shape of the workpiece.
Teaching efficiency is greatly improved. In addition, in this embodiment, since the teaching interval is managed by the moving distance, if the movement of the arm of the robot 1 is stopped during the teaching work, the teaching interval is managed by the time. Data is not stored unnecessarily.

〔Effect of the invention〕

As is clear from the above description, the present invention provides the following effects.

In the direct teaching work of the robot by force control, the movement interval that can be arbitrarily set by the teaching worker is used as the teaching interval, so the teaching data of the position and posture can be continuously and automatically transmitted at each movement interval. Can be taught. The teaching worker can perform the work simply by guiding the robot's arm, and there is no need to pay attention to travel time, and the worker can work at his or her own pace, making teaching work easier. The efficiency of teaching work can be improved.

In addition, when teaching work such as deburring work that follows the shape of a workpiece along the edge, it is possible to bring the hand effector into contact with the workpiece and teach while tracing the edge of the workpiece. It is possible to teach accurate position and posture.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a robot system to which the present invention is applied, FIG. 2 is a block diagram showing the configuration of a direct teaching device according to the present invention, and FIG. 3 is a diagram showing the operation of the direct teaching device according to the present invention. The flowchart, FIG. 4, is a work diagram showing an example of direct teaching work. [Explanation of symbols] 1... 2φ...Fist 4...-- 5... 6.6'... 7 a m a m- 8. Fist... 11...・ 11A... ・Robot, arm, wrist section, force sensor, workpiece, hand effect device, controller, teaching box, direct teaching routine call switch, teaching switch, teaching interval setting switch, speed calculation section, position detection section, teaching Data storage unit/movement interval calculation unit 11B φ ・ ・ 11C ・ ・ ・ 14 ・ −・ ・ 16 ・ ・ ・ ・ 17 ・ ・ ・ ・ 18 ・ ・ φ ・ Fig. 1

Claims (2)

[Claims] (1) A force sensor is provided on the wrist part of the arm to which the hand effector is attached, and the force signal outputted by the force sensor is input to the control means, and the arm is guided according to force control based on the force signal, and appropriate teaching is performed. In a direct teaching device for the position and posture of a robot, the device is configured to retrieve the position and posture of a robot's hand at a plurality of teaching points set at intervals via a position sensor and a position detection means and store it in a storage means, teaching interval setting means for arbitrarily setting the teaching interval as a movement interval; and the position detecting means storing the set teaching interval and extracting the output signal from the position sensor arranged in each part of the robot. input the position data, calculate the movement distance, compare this movement distance with the stored teaching interval, and store the teaching data of the position and posture of the robot in the storage means at the teaching point for each teaching interval. 1. A device for directly teaching the position and posture of a robot, comprising a teaching interval calculation means for storing the teaching interval. (2) In a direct teaching method for a robot in which a teaching worker applies a force to a force sensor of an arm and guides the arm according to force control based on a force signal output by the force sensor at this time to perform a teaching work, the arm of the robot While guiding
It is characterized by automatically capturing and storing the teaching data of the robot's position and posture for each teaching point determined by either the translational movement interval arbitrarily set by the teaching worker or the movement interval related to the rotation of the hand posture. A method for directly teaching the position and posture of a robot.