JP2009072833A - Direct instructing device of robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a direct instructing device for instructing complicated operation such as assembly work by an industrial robot, capable of efficiently performing instructing work and generating a work program reflecting the quick and slow action of the robot in direct instructing. <P>SOLUTION: This direct instructing device of the robot for performing instructions in a manner that a force sensor 3 detects force applied to a control handle 4 by an instruction operator, the robot 1 is operated by force control, and the operation of the robot 1 is recorded includes: a recording section 10 to record the position and speed of the robot 1 during instruction for every predetermined sampling time; an extraction processing section 11 extracting position data recorded in the recording section at intervals according to a change in speed date recorded in the recording section 10 and generating the path data of the robot 1; and a storage section 12 storing the generated path data. The control handle 4 is provided with a display part 5 presenting the generated path data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an industrial robot teaching apparatus, and more particularly to a direct teaching apparatus in which a teaching operator directly applies a force to a robot to operate the robot to perform teaching.

As a teaching method for industrial robots, in addition to the method of jogging each axis to record the teaching point with the desired position and orientation of the robot's hand, the operator (teaching operator) directly applies force to the robot Direct teaching to operate is known.
In a conventional direct teaching method for an industrial robot, an operator directly applies a force to the robot to move along a trajectory to be taught, and the position of each axis of the robot is set at a certain sampling time (for example, the entire path). There was a method of reading and recording every 10 to 100 [ms]. However, this method has a problem that the amount of data to be recorded becomes enormous, and it is extremely difficult to correct the route when a route is mistaken during teaching.
Therefore, as a countermeasure, the work to be taught to the robot is divided into a plurality of work ranges, and direct teaching is performed for each work range. Thereafter, the path data name to be reproduced, the reproduction order of each path data, management information, and interpolation information are included. There has been a method of creating a work program and causing the robot to perform a desired operation by reproducing the work program (for example, Patent Document 1). Patent Document 1 also discloses a method for generating path data for a robot to smoothly move between paths.
JP-A-8-19975

The direct teaching method of Patent Document 1 is a method in which an identification code is stored in path data for each work range, and then the path data is edited. Such a method is effective in work that can clarify the characteristics of work for each work range, such as painting work. However, when the movement of the worker itself, in other words, the slowness of the movement is a feature of the work as in the assembly work, it is necessary to utilize the movement itself including the movement speed of the operator at the time of direct teaching. Such a case cannot be handled by the conventional direct teaching method.
As described above, the method of recording / reproducing sampling data as it is increases the storage capacity and is not practical.
The present invention has been made in view of the above problems, and relates to a direct teaching device for teaching complicated operations such as assembly work by an industrial robot. It is an object of the present invention to provide a direct teaching device capable of generating a work program that reflects the speed of the operation of an operator at the time.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 includes an operation handle provided via a force sensor at a tip of an articulated robot, and the force applied to the operation handle by a teaching worker is detected by the force sensor and is detected. In a direct teaching apparatus for a robot that teaches by operating the robot by force control in accordance with force and recording the operation of the robot, the position and speed of the robot being taught are set at predetermined sampling times. A recording unit for recording, an extraction processing unit for extracting position data recorded in the recording unit at intervals according to changes in speed data recorded in the recording unit, and generating path data of the robot, and the generation A storage unit that stores the generated path data, and the operation handle includes a display unit that presents the generated path data.
According to a second aspect of the present invention, the extraction processing unit generates the path data by increasing the extraction interval of the position data recorded in the recording unit as the velocity data recorded in the recording unit increases. It is characterized by that.
According to a third aspect of the present invention, the operation handle includes a deadman switch, and the force control is performed only while the deadman switch is pressed.
According to a fourth aspect of the present invention, the display unit includes a touch panel, a switch for starting and stopping recording of the position and speed of the robot on the touch panel, and a switch for starting the generation of the path data by the extraction processing unit. Is displayed.
According to a fifth aspect of the present invention, the display unit includes a setting unit that sets a parameter for adjusting an interval at which the extraction processing unit extracts position data recorded in the recording unit.
The invention described in claim 6 is characterized in that the display section includes a graphic data display section that presents the position data recorded in the recording section and the generated path data by three-dimensional graphics display.
The invention according to claim 7 is characterized in that the display section is detachably installed from the operation handle.

According to the first aspect of the present invention, it is possible to generate path data reflecting the speed of the robot operation at the time of direct teaching, and to efficiently perform a work program in teaching work in a process requiring work skills such as assembly work. Can be generated. Further, since the operator can check the generated path data without actually operating the robot, it is more useful for efficiently performing the teaching work.
According to the second aspect of the present invention, since the extraction interval of the position data recorded at the time of direct teaching can be adjusted by the magnitude of the operation speed of the robot at the time of direct teaching, the stored data sampled at the time of direct teaching can be reduced. Thus, it is possible to achieve both the reproduction of the feature of the operation by the operator, and it is possible to provide a teaching device with extremely high practicality.
According to the third aspect of the present invention, since the position and speed of the robot are recorded only when the operator is surely holding the operation handle, unintended data can be recorded by applying force to the robot by mistake. This can prevent the teaching work from proceeding efficiently.
According to the invention described in claim 4, since the display function and the switch function are provided by adopting the touch panel, the display unit is extremely small and compact in the operation handle unit, which obstructs the operator's view during teaching work. This improves the efficiency of teaching work.
According to the fifth aspect of the present invention, it is possible to adjust the reproducibility of the generated path data with respect to the operation of the robot during direct teaching.
According to the sixth aspect of the present invention, the operation of the robot 1 during direct teaching and the generated path data can be confirmed without actually operating the robot, and the generated path data is intended by the operator. Therefore, the efficiency of teaching work can be improved.
According to the seventh aspect of the present invention, when there is a possibility of contact between the display unit and the surrounding environment in direct teaching of the canyon portion, the display unit can be arranged in a place where the operator can easily confirm the actual state. This is extremely useful for improving the efficiency of teaching work on the production line. In addition, the display unit can be used for teaching work for a plurality of robots.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Examples of the present invention will be described below. FIG. 1 is a configuration diagram of a robot direct teaching apparatus according to a first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes an articulated robot, and a hand 2 that can be opened and closed as an end effector is attached to the tip of the robot 1. A force sensor 3 is disposed between the tip of the robot 1 and the hand 2, and an operation handle 4 is fixed to the force sensor 3.
The force sensor 3 detects the direction and magnitude of the force applied to the operation handle 4, and the operator holds the operation handle 4 and applies force in a desired direction to operate the robot 1 and directly teach it. Details of the direct teaching procedure will be described later. The operation handle 4 is provided with a display 5 having a touch panel function and a deadman switch 4A.
As shown in FIG. 2, the display unit 5 uses the screen divided into a graphic data display unit 5A, a switch 5B, a parameter display / editing unit 5C, and a path generation execution switch 5D. The function of the switch 5B can be changed according to the teaching status, and a character representing the function is displayed each time.
In FIG. 2, a dotted line displayed on the graphic data display unit 5A represents path data when actually taught, and a solid line represents path data after extraction processing described later.

Reference numeral 6 denotes a control device for controlling the robot 1. The control device 6 includes an impedance control unit 7, a position / velocity control unit 8, a servo amplifier unit 9, a position data / velocity data recording unit 10, an extraction processing unit 11, and a storage unit 12 composed of a nonvolatile memory. A touch panel control unit 13, a work program decoding execution unit 16, a mode management unit 17, and an inverse conversion unit 18.
The impedance control unit 7 receives the output of the force sensor 3 and outputs a position command and a speed command according to an impedance model described later. Further, the command output from the impedance control unit 7 is converted into a command for each joint axis of the robot 1 by the inverse conversion unit 18.
The touch panel control unit 13 includes a three-dimensional graphic data generation unit 15 that generates graphic data to be displayed on the display unit 5, and a touch panel input / output signal management unit that detects a switch operation on the display unit 5 and transmits graphic data. 14.

  The mode management unit 17 is connected to the deadman switch 4A, and when the operator directly teaches, the modeman 17 presses down the deadman switch 4A to clearly indicate to the control device 6 that teaching is in progress. The mode management unit 17 switches on / off the function of the impedance control unit 7 according to the state of the deadman switch 4A.

  Here, the impedance model in the impedance control unit 7 is expressed as the following equation (1).

However, F: Operation force which is the output of the force sensor 3 x: Position of the hand 2 M: Inertia coefficient B: Viscosity coefficient K: Spring coefficient, both of which are real numbers.

  The inertial coefficient M, the viscosity coefficient B, and the spring coefficient K are appropriately adjusted in advance, and the robot 1 with respect to the force detected by the force sensor 3 is obtained by using x obtained by the equation (1) as a command to the robot 1. It is possible to change the operating characteristics during direct operation. Since impedance control is a known technique, a detailed description thereof is omitted.

A direct teaching procedure by the direct teaching apparatus of the present invention will be described.
An example of a work pattern taught by the operator is shown in FIG. FIG. 3 shows a state in which the operator 50 directly teaches the path data necessary for the robot 1 to automatically assemble the seat 51 in the vehicle body 52.
At this time, the operator 50 holds the operation handle 4 with the right hand and the sheet 51 with the left hand. As described above, one hand of the operator 50 who does not hold the operation handle 4 often has a work piece in actual work. Therefore, the hand which does not hold the operation handle 4 as in the conventional example. A method with a small programming box is not suitable for practical use. On the other hand, in the present invention, various operations relating to the direct teaching work can be performed only with the right hand holding the operation handle 4, and an efficient direct teaching apparatus can be realized.

Next, a description will be given of the control in the control device 6 when the robot 1 is guided by applying force to the operation handle 4 gripped by the operator 50 and directly teaches.
When the operator 50 depresses the deadman switch 4A of the operation handle 4, the mode management unit 17 receives the signal and turns on the function of the impedance control unit 7. At the same time, the touch panel input / output signal management unit 14 displays “ Send a signal to display “Teach Start”.
When the operator 50 confirms and presses the switch 5B displayed as “Teach Start” on the display 5, the touch panel input / output signal management unit 14 latches the pressed state, and the position data / speed data recording unit 10 stores the teaching data. At the same time as requesting the start of recording, “stop teaching” is displayed on the switch 5B.
The position data / speed data recording unit 10 starts recording and storing the position (angle) and speed of each joint axis of the robot 1 fed back to the position / speed control unit 8 in response to a recording request signal from the touch panel input / output signal management unit 14. I will do it. The sampling period of recording may be the same as the sampling period of the position / velocity control unit 8 or may be set to a longer period when rough operation teaching is sufficient. In addition, the number of data recorded at every sampling period is counted up to be an index for specifying data.
For example, position data is recorded and managed as P (1), P (2), P (3)... And velocity data is also V (1), V (2), V (3),.・ Recorded and managed as follows.

When the operator 50 actually starts the operation, the force sensor 3 detects the induced force of the operation handle 4 gripped by the operator 50, and an impedance model based on this force information, virtual inertia and viscosity (in the following embodiments, the spring coefficient = 0). The position control / speed command in the orthogonal coordinate system is calculated by the impedance control unit 7 based on the above. This command is inversely transformed into the joint coordinate system by the inverse transformation unit 18 to obtain a command for each joint. Based on the joint angle command / joint speed command and the joint angle and joint speed detected by a joint angle detector (not shown) provided in each drive part or each joint part of the robot 1, the position / speed control unit 8 The torque to be generated by the servo motor that is the driving source of the joint shaft is calculated. The servo amplifier unit 9 drives the servo motor of the robot 1 in accordance with a command from the position / speed control unit 8. In this way, the robot 1 operates along the route of the work for assembling the seat 51 in the vehicle body 52 in accordance with the guidance by the operator 50.
During this operation, the position data / speed data recording unit 10 continues recording. When the operation to be taught is completed and the operator 50 depresses the switch 5B on which “Teaching stop” is displayed, the touch panel input / output signal management unit 14 latches the depressing state, and the position data / speed data recording unit 10 finishes recording. Simultaneously with the request, “Teach Start” is displayed again on the display 5.

Next, when the operator 50 releases the deadman switch 4 </ b> A of the operation handle 4, the mode management unit 17 turns off the function of the impedance control 7 and simultaneously “passes” the touch panel input / output signal management unit 14 on the switch 5 </ b> B. Send a signal that says "Data can be generated." When the operator 50 visually confirms the display of “path data can be generated” on the switch 5B and presses the path generation execution switch 5D, the extraction processing unit 11 reads the data recorded in the position data / velocity data recording unit 10. read out.
The extraction processing unit 11 generates appropriate path data according to the read speed data, and stores the path data in the storage unit 12. More specifically, path data is generated based on the processing flow shown in FIG.
In FIG. 4, n, L, M, and Lmax are natural numbers, Lmax represents the number of data recorded in the position data / velocity data recording unit 10, and L and M are recorded in the position data / velocity data recording unit 10, respectively. For specifying the position data (P (1), P (2), P (3)...) And speed data (V (1), V (2), V (3)...) Used as an index. N is used as an index of generated path data.
Kc is a parameter (natural number) for adjusting the extraction interval when the path data is generated from the data recorded in the position data / velocity data recording unit 10. When Kc increases, the extraction interval from the recorded data becomes smaller (finer), and when Kc decreases, the extraction interval becomes larger (rougher). When Kc is constant, the larger the recorded speed data, the larger the path data extraction interval (rough), and the smaller the speed data, the smaller the path data extraction interval (fine). Become. That is, when the operator operates the robot 1 at a high speed during direct teaching, path data having a large extraction interval (coarse) is generated. Therefore, path data that reproduces the speed of movement by the operator during direct teaching is generated. be able to.

  Kc is set in advance by the operator using the parameter display / setting unit 5C. FIG. 5 shows an example of the parameter display / setting unit 5C. In FIG. 5, it comprises a display unit 5C1, a plus switch 5C2, a minus switch 5C3, and a decision switch 5C4. When the operator depresses the plus switch 5C2 / minus switch 5C3, the value of the parameter Kc displayed on the display unit 5C1 increases or decreases. After setting Kc to an appropriate value, Kc is stored in the extraction processing unit 11 when the decision switch 5C4 is pressed.

When the path generation execution switch 5D is pressed, the process starts from S1, and n and L are initialized in S2. The speed data is read in S3, and the index (M) of the position data to be read is determined according to the ratio between the parameter Kc and the size of the recorded speed data in S4. If | V (L) | / Kc is not divisible, the decimal part is rounded up to a natural number.
The position data P (M) is read from the position data / velocity data recording unit 10 in S5, and the read P (M) is stored in the storage unit 12 as the target position P1 (n) of the path data in S6. Subsequently, the index is counted up in S7. The above S3 to S7 are repeated until the end of the data recorded in the position data / velocity data recording unit 10.

The generated path data is converted into graphic data by the three-dimensional graphic data generation unit 15 and displayed on the graphic data display unit 5A as shown in FIG. At the same time, not only the generated path data but also the path data at the time of teaching recorded in the position data / velocity data recording unit 10 can be displayed at the same time.
The three-dimensional graphic data generation unit 15 is preliminarily set with data such as dimensions of each link portion of the robot 1 in order to generate graphic data from the path data.
By providing the display 5 on the operation handle 4, it is possible to confirm the operation trajectory of the directly taught work without performing the reproduction operation by the robot 1 and without leaving the robot 1. Further, the display unit 5 can be attached to and detached from the handle 4, and a single display unit 5 can be shared by a plurality of robots and used for direct teaching of each robot.

  The path data generated in this way is read from the storage unit 12 and is input to the position / velocity control unit 8 via the work program decoding execution unit 16 at the time of work execution. Since the deadman switch 4A is not pressed when the work is executed, the function of the impedance control unit 7 is in an OFF state, and the robot 1 performs a normal playback operation.

The figure which shows the whole structure of this invention The figure which shows the structure of the indicator of this invention The figure which shows the concrete work pattern to which this invention is applied Process flow diagram explaining the processing in the extraction processing unit of the present invention The figure which shows the parameter display and edit part of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot 2 Hand 3 Force sensor 4 Operation handle 4A Deadman switch 5 Display 5A Graphic data display part 5B Switch 5C Parameter display / adjustment part 5C1 Display part 5C2 Plus switch 5C3 Negative switch 5C4 Decision switch 5D Path generation execution switch 6 Controller 7 Impedance control unit 8 Position / speed control unit 9 Servo amplifier unit 10 Position data / speed data recording unit 11 Extraction processing unit 12 Storage unit 13 Touch panel control unit 14 Touch panel input / output signal management unit 15 3D graphic data generation unit 16 Work program decoding Execution unit 17 Mode management unit 18 Reverse conversion unit 50 Operator 51 Seat 52 Car body

Claims (7)

The articulated robot has an operation handle provided at the tip of the robot via a force sensor, the force applied to the operation handle by the teaching worker is detected by the force sensor, and the robot is controlled by force control according to the detected force. In the direct teaching device of the robot that teaches by recording the movement of the robot,
A recording unit that records the position and speed of the robot being taught at preset sampling times;
An extraction processing unit that extracts position data recorded in the recording unit at intervals corresponding to changes in speed data recorded in the recording unit and generates path data of the robot;
A storage unit for storing the generated path data;
The robot direct teaching apparatus, wherein the operation handle includes a display unit for presenting the generated path data.   The said extraction process part produces | generates the said path | pass data by increasing the extraction interval of the position data recorded on the said recording part, so that the speed data recorded on the said recording part is large. Robot direct teaching device.   The robot direct teaching apparatus according to claim 1, wherein the operation handle includes a deadman switch, and the force control is performed only while the deadman switch is pressed.   The display unit includes a touch panel, and displays on the touch panel a switch for starting and stopping recording of the position and speed of the robot, and a switch for starting the path data generation by the extraction processing unit. Item 2. A robot direct teaching apparatus according to Item 1.   2. The robot direct teaching apparatus according to claim 1, wherein the display unit includes a setting unit that sets a parameter for adjusting an interval at which the extraction processing unit extracts position data recorded in the recording unit. .   2. The robot direct teaching apparatus according to claim 1, wherein the display section includes a graphic data display section that presents the position data recorded in the recording section and the generated path data by a three-dimensional graphics display. .   The robot direct teaching apparatus according to claim 1, wherein the display unit is detachably installed from the operation handle.