JP2007000954A - Robot teaching device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot teaching device which avoids occurrence of a peculiar position of both arms during teaching a robot how to work, and also to provide a robot teaching method. <P>SOLUTION: The robot 1 is formed of: a manipulator device 10 having the plurality of arms; joints; and drive sources, and a traveling device 20. The robot teaching device 30 is comprised of: a teaching point input means 37; a traveling distance calculating means for obtaining a traveling direction and a traveling distance of the traveling device with a second joint 13b being kept bent, when a front end 14 of the manipulator device is positioned at each of a plurality of movement target locations T1 based on input teaching points; and a data generating means for generating robot control data by reflecting the obtained traveling direction and the traveling distance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a teaching apparatus and method for a robot including an articulated manipulator device and a traveling device thereof.

  The teaching playback type industrial robot requires an operation of setting an operation pattern called teaching. As a general form of teaching work, an operator confirms the position of an end effector (a general term for tools such as a welding gun attached to the tip of a robot arm) at the tip of a robot manipulator device using a teach pendant as a teaching means. Then, the robot is operated by operating the buttons of the teach pendant, etc., and the steps as recording data that summarizes the position and speed information for causing the robot to perform a predetermined operation are recorded one by one. This recorded series of steps constitutes one work program.

By the way, the operation region of a robot including an articulated manipulator device is determined according to the length of an arm constituting the manipulator device. For this reason, the manipulator device is mounted on the traveling device, and the operation region is expanded by conveying the manipulator device to a target position by driving the traveling device.
In the robot teaching apparatus having the traveling apparatus as described above, the distance from the origin position of the coordinate system of the traveling apparatus to the movement target point based on the teaching point is divided into stepped ranges and each distance is set in advance. The movement amount of the traveling device is set to a certain distance for each range (see, for example, Patent Document 1).
That is, in the robot teaching device, when the teaching point is input, the distance from the origin position to the target point is calculated, and the traveling distance by the traveling device is determined according to which distance range the calculated distance belongs to, As a result, the teaching work of the travel distance of the traveling device is not required, and the teaching work burden is reduced.
Japanese Patent Laid-Open No. 10-244481

However, as described above, the method for determining the moving distance of the traveling device according to the distance to the target point does not take into account the attitude of the manipulator device, and thus the following problems have occurred.
Here, in order to clarify the problem, a model in which a biaxial manipulator device is mounted on a traveling device will be described as an example. As shown in FIG. 9, when positioning the tip of the manipulator device 110 with respect to the target point T1, the conventional teaching device travels stepwise depending on the distance from the origin of the coordinate system of the traveling device 120 to the target point. In order to determine the movement amount of the device 120, depending on the case, the two arms 111 and 112 connected to the manipulator device 110 are in a fully extended posture (singular posture), and an excessive speed is generated in each joint 113. Further, as shown in FIG. 10, when moving between a plurality of continuous target points T1 to T4, the connecting arms 111 and 112 of the manipulator device 110 repeatedly bend and stretch, thereby repeatedly extending and contracting. Unnecessary acceleration / deceleration also occurs in the device 120. When such acceleration / deceleration occurs, the energy consumed by the drive motor, which is the drive source for the joints and the traveling device, becomes excessive, and the cycle time of a series of operations is extended.

  An object of the present invention is to prevent control data based on teaching from causing a specific posture in a manipulator device.

  According to a first aspect of the present invention, there is provided a robot including a manipulator device in which a plurality of arms are connected by a plurality of joints and a drive source is provided for each joint, and a traveling device that moves the manipulator device along a predetermined locus. In the teaching device, teaching point input means for inputting the teaching point of the robot, and a predetermined joint of the manipulator device when positioning the tip of the manipulator device for each of a plurality of movement target positions based on the input teaching point The travel distance calculation means for determining the travel direction and travel distance of the travel device in a state where the bending state is maintained, and the robot control data based on the teaching point reflecting the travel direction and travel distance determined by the travel distance calculation means And a data generation means for generating the data.

  The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the travel distance calculation means virtually changes the travel distance in a predetermined distance unit and a predetermined joint angle associated with the change. Is calculated, and an appropriate travel distance is specified from the obtained change in the joint angle.

  According to a third aspect of the present invention, there is provided a robot provided with a manipulator device in which a plurality of arms are connected by a plurality of joints and a drive source is provided for each joint, and a traveling device that moves the manipulator device along a predetermined locus. In the teaching device, when the traveling device is fixed when positioning the tip of the manipulator device for each of a plurality of movement target positions based on the teaching point input means for inputting the teaching point of the robot The operability calculating means for calculating the operability of the manipulator device and the operability when one of the joints of the manipulator device is fixed, and the display for displaying the calculated two operability or a comparison result of the magnitudes thereof. Means, a fixed object selecting means for inputting which one of the joints of the traveling device and the manipulator device should be fixed, and a selection by the fixed object selecting means. According, and a data generating means for generating control data for a robot which moves to the movement target position while fixing the driving device or joint, adopts a configuration that.

According to a fourth aspect of the present invention, there is provided a robot provided with a manipulator device in which a plurality of arms are connected by a plurality of joints and a drive source is provided for each joint, and a traveling device that moves the manipulator device along a predetermined locus. In the teaching method, the traveling direction of the traveling device in a state in which a predetermined joint of the manipulator device maintains a bent state when positioning the tip of the manipulator device for each of a plurality of movement target positions based on the teaching point of the robot And a travel distance calculation step for obtaining a travel distance, and a data generation step for generating the robot control data based on the teaching points by reflecting the travel direction and the travel direction obtained by the travel direction selection means. ing.
The above method is executed by at least an arithmetic device capable of executing predetermined information processing and a storage device capable of storing data.

  The invention according to claim 5 has the same configuration as that of the invention according to claim 4, and in the travel distance calculation step, the travel distance is virtually changed by a predetermined distance unit and a predetermined joint angle associated with the change is provided. Is calculated, and an appropriate travel distance is specified from the obtained change in the joint angle.

According to a sixth aspect of the present invention, there is provided a robot including a manipulator device in which a plurality of arms are connected by a plurality of joints and a drive source is provided for each joint, and a traveling device that moves the manipulator device along a predetermined locus. In the teaching method, when positioning the tip of the manipulator device for each of a plurality of movement target positions based on the teaching point of the robot, when the traveling device is fixed and one of the joints of the manipulator device is fixed The operability calculation step for calculating the operability of the vehicle, the display step for displaying the two operability calculated or their magnitudes, and the joint of the traveling device and the manipulator device based on the display contents of the display step The traveling object or the joint is fixed according to the fixing target selection process that accepts an input of which of these should be fixed and the selection by the fixing target selection process. One and a data generating step of generating a control data of the robot to move to the movement target position, adopts a configuration that.
The above method is executed by at least an arithmetic device capable of executing predetermined information processing and a storage device capable of storing data.

In the first or fourth aspect of the invention, the travel direction and travel distance of the travel device and each joint angle of the manipulator device are determined so that the tip of the manipulator device is positioned with respect to the movement target position. At this time, since the selection of the traveling direction of the traveling device and the calculation of the traveling distance are performed within a range in which the bending state of the predetermined one joint of the manipulator device can be maintained, the two arms connected by the joint are extended. Occurrence of a posture (unique posture) can be avoided, and an excessive increase in speed at each joint can be suppressed when positioning to a target position or moving from the target position to the next target position. .
This also prevents the occurrence of repeated bending and stretching operations for a given joint during successive operations to a plurality of movement target positions, suppresses the energy consumed by the drive source, and shortens the cycle time of a series of operations. As a result, it is possible to suppress delays in operation.

The travel locus of the traveling device may be a linear direction or a curved direction.
Further, as the joint that maintains the bent state, it is preferable to select either a joint located near the middle position of the entire length of the manipulator device or a joint located from the middle position to the base end (traveling device side). .
Further, maintaining the bent state is preferably to maintain the right angle state, and may maintain an angle within a range that increases or decreases within a preset range with respect to the right angle.

In the invention according to claim 2 or claim 5, when determining the traveling direction of the traveling device, first, the traveling portion is traveled a predetermined distance in the forward direction and the reverse direction along the movement locus to position the tip at the target position. The angle of the predetermined joint in the case of doing is calculated | required by calculation virtually, and the direction which can maintain a bending state is specified. Further, for each direction, a predetermined joint angle when the distal end portion is positioned at the target position by traveling by a predetermined distance is virtually obtained, and a travel distance at which the joint can be most bent is specified.
In this way, since the appropriate travel direction and travel distance for maintaining the predetermined joint flexion state for the travel device are obtained, the processing can be simplified and speeded up.
The unit distance to be changed for the travel distance is preferably a minute distance, but is preferably set appropriately from the viewpoint of the time that can be spent for processing.

The invention according to claim 3 or claim 6 is possible when positioning the tip of the manipulator device with respect to the movement target position in a state where the traveling device is fixed and a state where one joint of the manipulator device is fixed. Ask for operability and display it. The operator sees this, determines whether to fix the traveling device or one joint, selects one and inputs it from the fixing target selecting means.
As a result, the movement of the tip of the manipulator device can be performed while maintaining a highly manipulable state for each movement target position while reducing the calculation for one axis. Since the maneuverability of the posture (singular posture) in which the two arms connected to each other are extended becomes low, the occurrence thereof can be avoided. Therefore, when positioning to the target position or moving from the target position to the next target position, it is possible to suppress an excessive increase in speed at each joint.
This also prevents the occurrence of repeated bending and stretching operations for a given joint during successive operations to a plurality of movement target positions, suppresses the energy consumed by the drive source, and shortens the cycle time of a series of operations. As a result, it is possible to suppress delays in operation.

The travel locus of the traveling device may be a linear direction or a curved direction.
In addition, as a joint to be fixed when performing uniaxial fixation, either a joint located near the middle position of the entire length of the manipulator device or a joint located at the proximal end (traveling device side) from the middle position is selected. It is preferable.

[First embodiment]
(Overall configuration of the first embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a robot teaching system 50 according to the first embodiment.
The robot teaching system 50 includes a manipulator device 10 that holds an end effector such as a welding gun at a tip portion and moves the tip portion to an arbitrary position or directs the manipulator device 10 in a straight line. And a robot teaching device 30 that generates control data for causing the robot 1 to perform a predetermined operation based on a plurality of input teaching points.

(robot)
The above-described manipulator device 10 of the robot 1 includes a base 11 serving as a base, a plurality of arms 12 connected by joints 13, a servo motor (not shown) as a drive source provided for each joint 13, and each An encoder (not shown) for detecting the shaft angle of each servomotor is provided. And the end effector 15 (for example, welding gun etc.) according to the use of the robot 1 is equipped in the front-end | tip part 14 of each arm 12 connected.
Each of the joints 13 includes either a swing joint that pivots one end of the arm 12 and pivotally supports the other end, or a rotary joint that pivots the arm itself so that the arm 12 can rotate about its longitudinal direction. Composed. That is, the manipulator device 10 in this embodiment corresponds to a so-called articulated robot.

The traveling device 20 holds the base 11 of the manipulator device 10, conveys the entire manipulator device 10 along a certain straight traveling direction, and can position the manipulator device 10 at an arbitrary position in the straight traveling direction. .
The traveling device 20 includes a servo motor (not shown) as the conveyance drive source of the manipulator device 10 and includes an encoder (not shown) that detects the shaft angle of the servo motor.

(Robot teaching device)
The robot teaching device 30 includes a system program for controlling the robot teaching device 30 as a whole, a ROM 32 in which a teaching program for executing teaching of the robot 1 and various initial setting data are stored, and various programs stored in the ROM 32. Servo motors according to the torque values of the servo motors of the manipulator device 10 and the traveling device 20 determined according to the teaching program executed by the CPU 31. Servo control circuit 34 for energizing drive current, interface 35 for receiving encoder output provided in each servo motor, and buffer as storage means for storing control data of the robot 1 obtained by the processing of the above teaching program 36, The teaching point input means 37 such as a teach pendant for inputting the teaching point of the bot 1 and other various settings, the display means 38 which is a display for displaying predetermined information in various processes, and each of the above components And a bus 39 for connecting signals such that signals can be transmitted and received.
The buffer 36 may be any means that can store and hold the stored data so that it can be rewritten. For example, the buffer 36 includes a nonvolatile semiconductor memory or a so-called hard disk device.

(Processing of robot teaching device)
Main processes performed in the robot teaching apparatus 30 will be described with reference to FIGS. FIG. 2 is a flowchart showing processing based on the teaching program.
Here, in order to clarify the description of the processing of the robot teaching device 30, an example will be described in which control data of the robot 1 having a simplified configuration is generated for the interpolation points on the two-dimensional plane. .
That is, as shown in FIG. 3, in the simplified model of the robot 1, the traveling device 20 moves and positions the manipulator device 10 along the Y-axis direction on the horizontal XY plane, and the manipulator device 10 The distal end portion 14 can be positioned at an arbitrary position on the XY plane.
The simplified model of the manipulator device 10 includes first and second arms 12a and 12b and first and second joints 13a and 13b. The first joint 13a connects the first arm 12a to the X-. The second joint 13b is provided between the first arm 12a and the second arm 12b and can swing the second arm 12b in the XY plane. I support it. That is, the simplified model of the manipulator device 10 has two degrees of freedom, and the robot 1 can position the distal end portion 14 of the manipulator device 10 at an arbitrary position on the XY plane.
In the following description, as shown in FIG. 3A, a state in which both the first and second arms 12a and 12b are extended in the positive direction of the X-axis direction is defined as a reference posture, The angle of the first and second joints 13a and 13b is 0 °, the counterclockwise direction is the positive rotation direction, the rotation angle of the first joint 13a is θ1, and the rotation angle of the second joint 13b is Let θ2. The travel distance of the travel device 20 is L.

The robot teaching device 30 receives an input teaching when a plurality of teaching points for determining a trajectory of a target motion are sequentially input from the teaching point input unit 37 by an operator in order to cause the robot 1 to execute the target motion. A plurality of interpolation points passing through the locus based on the points are obtained, and the driving angle of the servo motor of each joint 13a, 13b and the traveling distance of the traveling device 20 for allowing the arm tip portion 14 to pass each interpolation point are calculated. At this time, the robot 1 is controlled to perform actual operations that pass through each interpolation point in accordance with the teaching point input operation, and the teaching points can be sequentially input while visually checking the actual operations. It has become.
Further, the robot teaching device 30 sequentially stores the drive angle of the servo motor of each joint 13a, 13b and the travel distance of the travel device 20 with respect to each interpolation point. That is, in the robot teaching device 30, the driving angle of each servo motor is obtained by calculation through teaching work, and this is recorded to generate control data.
During actual work, the generated control data is reproduced, and the servo motors of the robot 1 are driven according to the data, whereby the robot 1 reproduces the taught operation.
Hereinafter, processing from teaching to generation of control data in the robot 1 that is modeled as a simple two-axis will be described in detail. The following processing is processing performed by the CPU 31 by executing the teaching program.

(Teaching point input and interpolation point calculation)
When the teaching point input means 37 inputs the position of a teaching point that serves as an index of the movement trajectory of the distal end portion 14 of the robot arm (the position of the distal end of the plurality of arms 12 connected by each joint 13) (step). S1) The CPU 31 traces a straight line or a curve to be drawn before the tip 14 of the robot arm reaches the input teaching point and a plurality of interpolation points (moving purpose) arranged at predetermined intervals along the locus. The coordinates of (position) are obtained by a known calculation process (step S2).

(Processing as travel distance calculation means: determination of travel direction of travel device)
FIG. 4 is an operation explanatory diagram viewed from above when the moving operation is performed on the interpolation point T1.
When the interpolation point T1 is determined, the CPU 31 calculates the angles of the first and second joints 13a and 13b for moving the traveling device 20 forward by a minute distance ΔL to position the arm tip 14 at the interpolation point T1. (Step S3), the angle of the first and second joints 13a and 13b for positioning the arm tip 14 at the interpolation point T1 by moving backward by the distance ΔL is calculated (Step S4).

Further, when a plurality of solutions for the angles of the first and second joints 13a and 13b for positioning to the interpolation point T1 are obtained, the CPU 31 selects the one having the smallest change amount from the current angle. Shall.
Moreover, although the magnitude of ΔL may be set arbitrarily, it is preferable to set it smaller. However, it is desirable to select an appropriate value according to the processing speed of the CPU 31 because the calculation requires more time as ΔL is reduced by the processing of steps S6, S7 or S8, S9 described later.
Further, whichever of the processes of steps S3 and S4 may be preceded.

Next, the angle θ2 _{+ i} of the second joint 13b when the travel device 20 is moved forward by the distance ΔL is compared with the angle θ2 _−i of the second joint 13b when the travel device 20 is moved backward by the distance ΔL, and the travel is performed. It is determined whether the second joint 13b of the manipulator device 10 is close to a bent state (a state in which the joint angle is 90 ° (or 270 °)) if the device 20 is driven in either the front-rear direction (step S5).
For example, as shown in FIGS. 3 (A) and 3 (B), when the traveling device 20 moves forward closer to 90 ° (or 270 °) than when the traveling device 20 moves backward, the traveling device 20 moves forward. Movement is selected (step S5: YES).
On the other hand, when the direction in which the traveling device 20 is moved backward is closer to 90 ° (or 270 °) than the case in which the traveling device 20 is moved forward, the backward movement of the traveling device 20 is selected (step S5: NO).

In the above determination, if the arm tip 14 does not reach the interpolation point T1 regardless of whether the forward movement or the backward movement of ΔL is performed, the tip 14 comes closer to the interpolation point T1 in the forward and backward movements. A direction is selected.
If the arm tip 14 reaches the interpolation point T1 only when either ΔL is moved forward or backward, a direction in which the tip 14 can reach the interpolation point T1 is selected.

(Processing as travel distance calculation means: identification of travel distance of travel device)
In step S5, it is determined whether the traveling device 20 should be driven in the forward direction or in the backward direction, and when the forward movement of the traveling device 20 is selected, the first when the traveling device 20 is further moved forward by ΔL. The joint angles of the second joints 13a and 13b are obtained (step S6).
Then, the angle θ2 _{+ i} of the second joint 13b before adding ΔL to the advance distance is compared with the angle θ2 _{+ i + 1} of the second joint 13b after adding ΔL. It is determined whether the joint angle of the second joint 13b is close to 90 ° (or 270 °) (step S7).
As a result, if ΔL is further added to the advance distance and the joint angle of the second joint 13b approaches 90 ° (step S7: NO), the process returns to step S6, and ΔL is further added to the advance distance. The determination whether or not the angle of the second joint 13b is close to 90 ° is repeated.
If the joint angle of the second joint 13b deviates from 90 ° when ΔL is further added to the advance distance, the travel distance before adding ΔL is determined as the appropriate value of the traveling device 20.
By repeating the processes of step S6 and step S7, the forward movement distance of the traveling device 20 is increased by ΔL, and the movement distance at which the second joint 13b is closest to 90 ° can be specified.

When the backward movement is selected in step S5, the joint angles of the first and second joints 13a and 13b when the traveling device 20 is further moved backward by ΔL are obtained (step S8).
Then, the angle θ2 _-i of the second joint 13b when adding ΔL to the retreat distance is compared with the angle θ2 _-i-1 of the second joint 13b after adding ΔL. It is determined whether the joint angle of the second joint 13b is close to 90 ° (or 270 °) (step S9).
As a result, when ΔL is further added to the receding distance, if the joint angle of the second joint 13b approaches 90 ° (step S9: NO), the process returns to step S8, and ΔL is further added to the receding distance. The determination whether or not the angle of the second joint 13b is close to 90 ° is repeated.
If the joint angle of the second joint 13b deviates from 90 ° when ΔL is further added to the retreat distance, the travel distance before adding ΔL is determined as the appropriate value of the traveling device 20.
By repeating the processes of step S8 and step S9, the backward movement distance of the traveling device 20 is increased by ΔL, and the movement distance at which the second joint 13b is closest to 90 ° can be specified.

(Robot tracking control)
When the appropriate moving direction and moving distance of the traveling device 20 are determined by the process of step S7 or S9, the CPU 31 performs operation control for driving the traveling device 20 according to the determined direction and the first and the first and second values obtained in step S6 or S8. Operation control for driving the manipulator device 10 is performed according to the angles of the second joints 13a and 13b (step S10).
Thereby, the arm front-end | tip part 14 of the manipulator apparatus 10 is positioned by the interpolation point T1.

(Processing as data generation means)
Next, the moving direction and moving distance of the traveling device 20 with respect to the interpolation point T1 and the joint angles of the first and second joints 13a and 13b of the manipulator device 10 are recorded in the buffer 36 as control data of the robot 1 ( Step S11).

Then, it is determined whether the interpolation point T1 is the final interpolation point for the input teaching point. If there is a next interpolation point (step S12: NO), the process returns to step S3, and a new interpolation point is obtained. The proper moving direction and moving distance of the traveling device 20 and the angles of the first and second joints 13a and 13b of the manipulator device 10 are calculated.
If the interpolation point T1 is the final interpolation point for the input teaching point (step S12: YES), the process ends.
As a result, the proper movement direction and movement distance of the traveling device 20 at all interpolation points with respect to all teaching points and the angles of the first and second joints 13a and 13b of the manipulator device 10 perform a series of operations. Is recorded in the buffer 36 as control data.

When the teaching device 30 has an operation control program in addition to the robot teaching program, the control data generated in this way is read out from the buffer 36 by executing the operation control program, and sequentially. Operation control of the traveling device 20 and the manipulator device 10 for each interpolation point is executed. That is, the robot 1 can faithfully reproduce the operation input in the teaching work.
When a separate control device for the robot 1 is provided, the control data generated in the buffer 36 is read out by communication means such as a recording medium or a LAN, and is input by teaching work according to the operation control program of the control device. The movement is controlled so that the robot 1 reproduces the movement.

  In the above processing, the processing from step S3 to S7 or S3 to S9 corresponds to the travel distance calculation step, and the processing in step S11 corresponds to the data generation step.

(Effect of robot teaching system)
In the teaching device 30, when the distal end portion 14 of the manipulator device 10 is positioned with respect to each interpolation point serving as the movement target position, the second joint 13 b travels so as to maintain about 90 ° (or 270 °). Since the travel direction of the device 20 is selected and the travel distance is specified, the occurrence of the extended postures (singular postures) of the first and second joints 13a and 13b connected to the second joint 13b is avoided. It is possible to suppress an excessive increase in speed at each joint during positioning to an interpolation point or movement from the interpolation point to the next interpolation point.
Accordingly, when the plurality of interpolation points are continuously moved, the second joint 13b is prevented from being repeatedly bent and extended, thereby suppressing the energy consumption of the servo motor and a series of work cycles. It is possible to shorten the time and suppress the delay of the operation.
Further, when the operating direction of the traveling device 20 is specified, the joint angles θ2 _{+ i} and θ2 _-i of the second joint 13b when the traveling device 20 is moved by the distance ΔL between the forward direction and the reverse direction are determined. Virtually obtained by calculation, the direction in which it is close to 90 ° (or 270 °) is selected.
Further, when the travel distance of the travel device 20 is specified, the travel is performed by the distance ΔL, and the joint angle θ2 _{+ i} or θ2 _{−i of} the second joint 13 b is closest to 90 ° (or 270 °) ( It is specified by obtaining (integer multiple of ΔL).
In this way, since an appropriate travel direction and travel distance are obtained for the travel device 20, it is possible to simplify and speed up the processing.

(Other)
In the processing of the teaching device 30, the biaxial manipulator device 10 is illustrated, but the same teaching processing is performed on the manipulator device 10 having more joints as shown in FIG. It goes without saying that it is also good.
In this case, as in the example of the biaxial manipulator device 10 described above, the joints (the arms connected to each other) are connected so that the two arms 12 connected to each other swing in the same plane with respect to the other. Travel distance calculation means for calculating the travel direction and travel distance of the travel device 20 so that the arms 12 connected to each other can be bent at 90 ° (or 270 °). It is desirable to perform the process (the process from step S3 to S9).
Further, when the manipulator device 10 has a plurality of such joints, a joint or an intermediate position that is close to an intermediate position in the longitudinal direction in a state where all of the plurality of arms are linearly extended. As the travel distance calculation means, the travel direction and travel distance of the travel device 20 are calculated so as to maintain the 90 ° (or 270 °) bent state of the joint provided between the base end position and the base end position. It is desirable to do.

Further, the traveling device 20 is not limited to the straight traveling operation as described above. For example, like the traveling device 21 shown in FIG. 5, the mounted manipulator device 10 may be moved and positioned in the circumferential direction, or the manipulator device 10 may be rotated by a rotary stage type. .
In that case, in the processing as the travel distance calculation means, the CPU 31 changes the forward and reverse rotation directions of the travel device 20 so that the predetermined joint in the manipulator device 10 toward the interpolation point T1 is close to 90 ° (or 270 °). Obtain the rotation angle and specify the rotation angle.

[Second Embodiment]
(Outline of the second embodiment)
A second embodiment of the present invention will be described with reference to FIGS. The hardware configuration of the robot teaching system according to the second embodiment is the same as that of the first embodiment, and the processing in teaching work is different from that of the first embodiment. Therefore, the teaching processing will be mainly described. To do.

(Processing of robot teaching device)
Main processes performed in the robot teaching device 30 will be described with reference to FIGS. FIG. 6 is a flowchart showing processing based on the teaching program. Also in the second embodiment, a case where the manipulator device 10 is simplified as a biaxial model and the control data of the robot 1 with a simplified configuration is generated for the interpolation points on the two-dimensional plane will be described as an example. I will do it.
Further, the configuration of the robot 1 that has been simplified, the basic posture of the robot 1, and the symbols L, θ1, and θ2 are the same as those in the first embodiment (see FIG. 3).

The robot teaching device 30 according to the second embodiment obtains a plurality of interpolation points that pass through the locus based on the input teaching points, and causes the arm tip portion 14 to pass the interpolation points and the servo motors and travels of the joints 13. The drive angle of the servo motor of the device 20 is calculated. At this time, the positioning operation for each interpolation point is performed in the traveling axis fixing mode in which the traveling device 20 is not driven and in the single axis fixing in which one joint (second joint 13b in the present embodiment) of the manipulator device 10 is not driven. The mode can be selected for each interpolation point, and when the mode is selected by the operator, the robot 1 is controlled to perform an actual operation that passes through each interpolation point according to the selection. It is possible to input teaching points sequentially while visually observing the actual operation.
In addition, the robot teaching device 30 stores the drive angle of the servo motor of each joint 13a, 13b or the travel distance of the travel device 20 according to the mode selected for each interpolation point, and generates control data.
By performing operation control according to such control data, the robot 1 can reproduce the teaching operation.
Hereinafter, processing from teaching to generation of control data in the robot 1 that is modeled as a simple two-axis will be described in detail. The following processing is processing performed by the CPU 31 by executing the teaching program.

(Processing as maneuverability calculation means: calculation of Jacobian)
If the position of the first joint 13a in the basic posture of the robot 1 shown in FIG. 3A is the origin of the XY coordinates, the coordinates of the tip position (X, Y) of the manipulator device 10 are expressed by the following equation (1). Can be represented.
However, the lengths of the first and second arms 12a and 12b are assumed to be 1 for simplification of calculation, the rotation angle of the first joint 13a is θ1, the rotation angle of the second joint 13b is θ2, and the traveling Let L be the travel distance of the device.

The CPU 31 calculates the traveling axis fixed mode Jacobian J1 from the above equation (1) according to the following equation (2), and calculates the uniaxial fixed mode Jacobian J2 according to the following equation (3) (step S21).

Further, the CPU 31 calculates an expression for obtaining the operability M1 in the traveling axis fixed mode from the Jacobian J1 in the traveling axis fixed mode. The manipulability is a value that is an index of the ease of movement of the distal end portion 14 of the manipulator device 10, and the maneuverability M1 in the traveling axis fixed mode is a determinant of Jacobian J1 as shown in the following equation (4). It can be obtained from the absolute value.
Similarly, the CPU 31 calculates an equation for obtaining the operability M2 in the uniaxial fixed mode from the Jacobian J2 in the uniaxial fixed mode. Such manipulability M2 can be obtained from the absolute value of the determinant of Jacobian J2 as shown in the following equation (5) (step S22).

(Teaching point input and interpolation point calculation)
Next, when the teaching point position is input from the teaching point input means 37 as an indicator of the movement locus of the tip 14 of the robot arm (step S23), the CPU 31 inputs the tip 14 of the robot arm. The trajectory of a straight line or a curve to be drawn before reaching the teaching point and the coordinates of a plurality of interpolation points (movement target positions) arranged at predetermined intervals along the trajectory are obtained by known arithmetic processing (step S24).

(Calculation of each joint angle or mileage)
When the interpolation point T1 is determined, the CPU 31 calculates joint angles θ1 and θ2 of the first and second joints 13a and 13b for positioning to the interpolation point T1 in the traveling axis fixed mode (step S25). Similarly, the CPU 31 calculates the travel distance L for positioning at the interpolation point T1 in the uniaxial fixed mode and the joint angle θ1 of the first joint 13a (step S26). These are calculated by substituting a fixed value (L or θ2 in the posture at the time of calculation) into L or θ2 of the above-described formula (1) and substituting the coordinate value of the interpolation point T1 into X and Y.
Note that either step S25 or S26 may be executed first.

(Processing as operability calculation means: calculation of operability)
Next, the CPU 31 calculates the operability at the interpolation point T1 in the traveling axis fixed mode and the operability at the interpolation point T1 in the uniaxial fixed mode (step S27).
For the operability in the travel axis fixed mode, the joint angle θ1, θ2 of the first and second joints 13a, 13b obtained in step S25 and the value of the travel distance L as a fixed value are substituted into the above-described equation (4). (The calculated θ2 is substituted because the parameter of the equation (4) is only θ2 depending on the configuration of the robot 1).
The operability in the uniaxial fixed mode is the value of the joint angle θ1 of the first joint 13a obtained in step S26 and the joint angle θ2 of the second joint 13b determined as the travel distance L and a fixed value in the above equation (5). (Note that the calculated θ1 and θ2 set to a fixed value are substituted because the parameters of the equation (5) are only θ1 and θ2 depending on the configuration of the robot 1).

Here, the operability in each mode is obtained from the specific posture of the robot 1 that is modeled as a simple biaxial model shown in FIGS. 7 and 8, and the relationship between the operability value and the posture of the robot 1 will be described. I decided to. FIG. 7 shows a case where the joint angle θ1 of the first joint 13a of the manipulator device 10 of the robot 1 is −45 ° and the joint angle θ2 of the second joint 13b is 90 °, and FIG. The case where the joint angle θ1 of the first joint 13a of the manipulator device 10 is 60 ° and the joint angle θ2 of the second joint 13b is 0 ° is shown.
In the example of FIG. 7, the operability M1 = | sin90 ° | = 1 in the traveling axis fixed mode, and the operability M2 = | sin−45 ° + sin45 ° | = 0 in the uniaxial fixed mode. That is, it can be seen that the operability is high in the traveling axis fixed mode, and the operability is low in the uniaxial fixed mode. For example, when the distal end portion 14 of the manipulator device 10 is moved in the direction of the arrow shown in FIG. 7, the moving operation can be suitably performed in the traveling axis fixed mode, but the movable operation is not possible in the single axis fixing mode. This confirms the difference in height.
On the other hand, in the example of FIG. 8, the maneuverability M1 = | sin0 ° | = 0 in the traveling axis fixed mode, and the maneuverability M2 = | sin60 ° + sin60 ° | = √3 in the uniaxial fixed mode. That is, it is understood that the maneuverability is low in the traveling axis fixed mode and the maneuverability is high in the single axis fixed mode. For example, when the distal end portion 14 of the manipulator device 10 is moved in the direction of the arrow shown in FIG. 8, the moving operation can be suitably performed in the uniaxial fixed mode, but the movable operation is not possible in the traveling axis fixed mode. This confirms the difference in height.

(Processing to display operability comparison results)
Next, the CPU 31 compares the operability at the interpolation point T1 in the calculated travel axis fixed mode with the operability at the interpolation point T1 in the single axis fixed mode, and the operability in any mode increases. Operation control for displaying the above on the display means 38 is performed (step S28).
Note that the operability value of each mode may be displayed without performing a size comparison.
Next, the CPU accepts a selection input from the input unit 37 as to whether the movement positioning is performed with respect to the interpolation point T1 in either the travel axis fixed mode or the single axis fixed mode (step S29). That is, the input unit 37 functions as a fixed target selection unit.

(Robot tracking control)
When the mode selection by the operator is performed by the process of step S29, the CPU 31 controls the operation of the traveling device 20 and the manipulator device 10 according to the selected mode (step S30).
That is, when the traveling axis fixing mode is selected, only the joints 13a and 13b of the manipulator device 10 rotate without driving the traveling apparatus 20, and when the uniaxial fixing mode is selected, Only the first joint 13a and the traveling device 20b are driven without driving the second joint 13b of the manipulator device 10, and the arm tip 14 of the manipulator device 10 is positioned at the interpolation point T1.

(Processing as data generation means)
Next, the moving direction and moving distance of the traveling device 20 with respect to the interpolation point T1 and the joint angles of the first and second joints 13a and 13b of the manipulator device 10 are recorded in the buffer 36 as control data of the robot 1 ( Step S31).

Then, it is determined whether the interpolation point T1 is the final interpolation point for the input teaching point. If there is a next interpolation point (step S32: NO), the process returns to steps S25 and S26, and a new interpolation is performed. Regarding the points, the appropriate travel direction and travel distance of the travel device 20 in the travel axis fixed mode and the single shaft fixed mode, and the angles of the first and second joints 13a and 13b of the manipulator device 10 are calculated.
If the interpolation point T1 is the final interpolation point for the input teaching point (step S32: YES), the process is terminated.
As a result, the proper movement direction and movement distance of the traveling device 20 at all interpolation points with respect to all teaching points and the angles of the first and second joints 13a and 13b of the manipulator device 10 perform a series of operations. Is recorded in the buffer 36 as control data.

Similarly to the first embodiment, when the teaching device 30 has an operation control program in addition to the robot teaching program, the control data generated in this manner is also used for the robot 1 using the control data. It is possible to control the robot 1 to faithfully reproduce the operation input in the teaching work.
When a separate control device for the robot 1 is provided, control data is read into the buffer 36 by a communication means such as a recording medium or a LAN, and the robot 1 is controlled according to an operation control program of the control device.

  In the above processing, the processing from step S21 to S27 corresponds to the operability calculation step, the processing in step S29 corresponds to the fixed object calculation step, and the processing in step S31 corresponds to the data generation step.

(Effect of the second embodiment)
In the teaching device 30 according to the second embodiment, since the operability M1 and M2 for positioning at the interpolation point in the traveling axis fixed mode and the single axis fixed mode are obtained and which is larger is displayed on the display unit 38, The operator sees this and can appropriately select the mode. Further, by operating the robot 1 with the control data generated by the teaching operation, the robot 1 is moved in a highly manipulable mode for each interpolation point while reducing the calculation for one axis. It is possible to avoid such a posture (unique posture) that the first and second arms 12a and 12b are extended so that the operability becomes low. Therefore, when positioning to the target position or moving from the target position to the next target position, an excessive increase in speed at each joint 13a, 13b is suppressed, and at the time of continuous movement of the interpolation points, bending is greatly caused. Without repeating the expansion, the energy consumption of the servo motor can be suppressed, the cycle time can be shortened, and the operation delay can be suppressed.

(Other)
In the case of the second embodiment as well, in the processing of the teaching device 30, the same teaching processing may be performed on the manipulator device 10 having more joints as shown in FIG. Needless to say. In that case, the joint to be fixed in the uniaxial fixing mode connects the two arms in a bent state, and is provided between the joint close to the intermediate position of the entire length of the manipulator device 10 or between the intermediate position and the proximal end position. It is desirable to fix the joint.
In the case of multi-axis, the tip position coordinates in the XYZ coordinate system are calculated using the transformation matrix of each joint, and based on this, the Jacobian J in each mode is calculated, and its determinant From the above, the operability M can be obtained.
When there is a redundant axis, the operability can be obtained from M = √ (det (JJ ^T )).
Further, the traveling device 20 is not limited to the straight traveling operation as described above, and may be a device that rotates the manipulator device 10 in a curved movement manner like the traveling device 21 of FIG. 5 described above.
Further, in the teaching process described above, the steps from S21 to S23 may be performed until the calculation of manipulability in steps S26 and S27, but it is desirable that the steps be performed before the process of step S25.

It is a schematic block diagram of the robot teaching system which is 1st embodiment. It is a flowchart which shows the process based on the teaching program in 1st embodiment. FIG. 3A is an explanatory diagram showing a basic posture of a simplified model in which the robot manipulator device is biaxial, and FIG. 3B is an explanatory diagram showing various parameters of the simplified model. FIG. 4A is an operation explanatory view showing the positioning operation for the interpolation point when the simplified model robot moves forward, and FIG. 4B is the positioning operation for the interpolation point when the simplified model robot moves backward. It is operation | movement explanatory drawing which shows. It is a perspective view which shows the other example of a traveling apparatus. It is a flowchart which shows the process based on the teaching program in 2nd embodiment. It is operation | movement explanatory drawing which shows the case where the 1st joint angle of a robot exists in the attitude | position which is -45 degrees and a 2nd joint angle is 90 degrees. FIG. 11 is an operation explanatory diagram illustrating a case where the robot has a posture in which the first joint angle is 60 ° and the second joint angle is 0 °. It is explanatory drawing which shows the problem of a prior art example. It is explanatory drawing which shows the other problem of a prior art example.

Explanation of symbols

1 Robot 10 Manipulator Device 12a First Arm 12b Second Arm 13a First Joint 13b Second Joint 20 Traveling Device 30 Teaching Device 31 CPU
32 ROM
34 Buffer (storage means)
37 Input means (teaching point input means, fixed object selection means)
38 Display means 50 Robot teaching system

Claims (6)

In a robot teaching apparatus comprising: a plurality of arms connected by a plurality of joints; and a manipulator device having a drive source for each joint and a traveling device for moving the manipulator device along a predetermined locus.
Teaching point input means for inputting the teaching point of the robot;
When positioning the distal end portion of the manipulator device for each of a plurality of movement target positions based on the input teaching points, the traveling direction of the traveling device in a state where a predetermined joint of the manipulator device is maintained in a bent state, and A travel distance calculating means for determining a travel distance;
A robot teaching apparatus, comprising: data generation means for generating control data of the robot based on the teaching points by reflecting the traveling direction and the traveling distance obtained by the traveling distance calculating means.   The travel distance calculating means virtually changes the travel distance in a predetermined distance unit, calculates the predetermined joint angle associated with the change, and specifies an appropriate travel distance from the obtained change in the joint angle. The robot teaching apparatus according to claim 1. In a robot teaching apparatus comprising: a plurality of arms connected by a plurality of joints; and a manipulator device having a drive source for each joint and a traveling device for moving the manipulator device along a predetermined locus.
Teaching point input means for inputting the teaching point of the robot;
When positioning the tip of the manipulator device for each of a plurality of movement target positions based on the input teaching points, the operability when the traveling device is fixed and one of the joints of the manipulator device are fixed. Operability calculating means for calculating the operability of the case,
Display means for displaying the calculated two operability values or a comparison result of the magnitudes thereof;
A fixed object selecting means for inputting which one of the joints of the traveling device and the manipulator device should be fixed;
A robot teaching apparatus comprising: data generation means for generating control data of the robot that moves to a movement target position while fixing the traveling apparatus or joint according to the selection by the fixing target selection means. In a robot teaching method comprising a plurality of arms connected by a plurality of joints and a manipulator device provided with a drive source for each joint and a traveling device for moving the manipulator device along a predetermined locus.
When the distal end portion of the manipulator device is positioned for each of a plurality of movement target positions based on the teaching points of the robot, the traveling direction and the traveling of the traveling device in a state where a predetermined joint of the manipulator device is maintained in a bent state. A mileage calculating step for obtaining a distance;
A robot teaching method, comprising: a data generation step of generating control data of the robot based on the teaching point by reflecting the traveling direction and the traveling direction obtained by the traveling direction selection means.   In the travel distance calculation step, the travel distance is virtually changed in a predetermined distance unit, the predetermined joint angle associated with the change is calculated, and an appropriate travel distance is specified from the change in the obtained joint angle. The robot teaching method according to claim 4. In a robot teaching method comprising a plurality of arms connected by a plurality of joints and a manipulator device provided with a drive source for each joint and a traveling device for moving the manipulator device along a predetermined locus.
When positioning the tip of the manipulator device for each of a plurality of movement target positions based on the teaching points of the robot, when the traveling device is fixed and one of the joints of the manipulator device is fixed An operability calculation step of calculating the operability of
A display step for displaying the calculated two operability or the magnitude of these two;
Based on the display content of the display step, a fixation target selection step for receiving an input on which of the travel device and the joint of the manipulator device should be fixed,
A robot teaching method comprising: a data generation step of generating control data of the robot that moves to each of the movement target positions while fixing the traveling device or joint according to the selection in the fixing target selection step.

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