JP3767643B2 - Teaching force sensor - Google Patents

Description

[Industrial application fields]
The present invention relates to a simple force sensor device for direct teaching of a manipulator that can obtain force information in six axial directions of translation and rotation from force information of three translational axes.
[0002]
[Prior art]
Conventionally, a so-called direct teach system of a manipulator is as shown in FIG. Such a system has been devised in many ways including Japanese Patent Application Laid-Open No. 59-157715. In the figure, 101 is a manipulator body composed of several joints and links, 102 is a six-axis force sensor attached to the tip of the manipulator body 101, 103 is a teaching point at the tip of the manipulator body 101, and 104 is a six-axis force sensor 102. Axis force information, 105 is a target impedance, 106 is a trajectory correction amount of the target impedance 105, 107 is an original target trajectory, 108 is a new target trajectory that is the sum of the original target trajectory 107 and the trajectory correction amount 106, 109 Is a servo controller that inputs a new target trajectory 108, and 110 is an output of the servo controller that is applied to each actuator of the manipulator body 101. Thus, conventionally, when direct teaching is performed in a 5-axis or 6-axis multi-degree-of-freedom manipulator, the 6-axis force sensor 102 is arranged at the tip of the manipulator body 101, and force information in 6 axes directions of translation and rotation is provided. The force control system is configured based on this, and the motion of the manipulator is controlled to realize the teaching operation that makes the manipulator move in the direction in which the teacher applied the force. It was.
[0003]
[Problems to be solved by the invention]
However, in the prior art, since the 6-axis force sensor 102 is used, the structure of the force sensor is complicated, and there are problems that manufacturing is difficult and manufacturing cost is high. In addition, because the force information of 6 axes of translation and rotation is measured simultaneously, the motion for teaching is inevitably 6 directions of translation and rotation, which confuses the instructor and lowers the teaching point positioning accuracy. I was letting.
Accordingly, the present invention provides a simple teaching force sensor device that is simple in structure and capable of measuring force information of six axes and that is easy for a teacher to teach by separating translation and rotation teaching operations. It is the purpose.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a force sensor device for teaching a manipulator by force control using a force sensor , wherein the teaching force sensor device includes a translational triaxial force sensor provided on a manipulator hand, and a translational direction sensor. A changeover switch for switching between force measurement and force measurement in the rotational direction, a selection switch for selecting any one of the three rotational directions, and a coordinate axis for translation and rotational motion of the manipulator hand The coordinate axes set in the translational three-axis force sensor have their origins located at positions other than the other coordinate axis. Further, the coordinate axes of the translational and rotational movements of the manipulator hand and the coordinate axes of the translational triaxial force sensor are arranged so as to be parallel to each other.
[0005]
[Action]
By the above means, it is possible to provide a teaching force sensor device that is simple in structure and capable of measuring force information of six axes and that is easy for a teacher to teach by separating translation and rotation teaching operations.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a teaching force sensor according to the present invention. In the figure, 1 is a manipulator body comprising several links, 2 is a translational triaxial force sensor attached to the tip of the manipulator body 1, 3 is the center of the force measurement coordinate of the translational triaxial force sensor 2, and 4 is a translational triaxial force. Force measuring coordinates of the sensor 2, 5 is a teaching coordinate of a teaching point of a manipulator hand provided at the tip of the manipulator body 1, 6 is a teaching point of a manipulator hand, 7 is translational triaxial force information by the translational triaxial force sensor 2, 8 is a selector switch for switching between translation and rotation, 9 is force information of the translational three axes after coordinate conversion, 10 is a selection switch for selecting any one of the three rotation axes, and 11 is coordinate conversion. , 12 is the target impedance, 13 is the trajectory correction amount, 14 is the original target trajectory, 15 is the new target trajectory, 16 is the servo controller, and 17 is the manipulator. Output of servo controller output to the actuator, 18 is a switching point to translation, 19 is a switching point to rotation, 20 is a switching point to rotation in the X-axis direction, 21 is a switching point to rotation in the Y-axis direction, 22 is a switching point to rotation in the Z-axis direction, 23 is rotational force information in the X-axis direction, 24 is rotational force information in the Y-axis direction, 25 is rotational force information in the Z-axis direction, and 26 is coordinate conversion of translational force. Reference numeral 27 denotes coordinate conversion of rotational force. In such a configuration, the force measurement coordinates 4 of the translational three-axis force sensor 2 do not come in a straight line with the teaching coordinates 5 of the teaching point at the teaching point 6 of the manipulator hand provided at the tip of the manipulator body 1. Are arranged as follows. The translational triaxial force information 7 based on the force measurement coordinates 4 measured by the translational triaxial force sensor 2 is sent to the changeover switch 8.
First, the translational force measurement and translational movement for the teaching point 6 are realized as follows. When the changeover switch 8 is closed to the translation switching point 18, the translational triaxial force information 7 is subjected to the translational force coordinate conversion 26, and then the teaching point teaching point 6 of the manipulator hand is taught. As force information 9 having three degrees of freedom for translation with respect to the coordinate 5, a trajectory correction amount 13 in the translation direction is calculated from the target impedance 12. This trajectory correction amount 13 is sent to the servo controller 16 as a new target trajectory 15 in addition to the original target trajectory 14. The servo controller 16 controls the movement of each actuator of the manipulator body 1 by the output 17 of the servo controller. With the above operation, the translational force applied to the translational triaxial force sensor 2 can be realized as if it is added to the teaching point 6 and the manipulator body 1 follows the translational force.
[0007]
Further, the measurement of the rotational force and the rotational motion with respect to the teaching point 6 are realized as follows. The force measurement coordinate 4 corresponding to the measurement axis of the translational triaxial force sensor 2 and the coordinate system of the hand of the manipulator are arranged so that the coordinate axes are not parallel to each other and do not come on a straight line. At this time, if the translational force is measured among the forces applied to the translational triaxial force sensor 2, the rotational force for the teaching point 6 can be obtained from this information. For example, the translational force in the plane between the X ′ axis and the Z ′ axis of the coordinate system of the translational triaxial force sensor 2 is set as the rotational force with respect to the Y axis at the teaching coordinate 5 of the teaching point of the hand of the manipulator. That is, the magnitude of the translation force vector is multiplied by the distance between the vector and the teaching point 6 to obtain a rotational force. Similarly, the translational force in the plane between the Z ′ axis and the Y ′ axis is the rotational force with respect to the X axis at the teaching coordinate 5 of the teaching point. Further, the translational force in the plane where the X ′ axis and the Y ′ axis meet is the rotational force with respect to the Z axis at the teaching coordinate 5 of the teaching point.
When the changeover switch 8 is closed to the changeover point 19 for rotation, the translational triaxial force information 7 of the force sensor is sent to the selection switch 10. When the selection switch 10 is closed to the rotation switching point 20 in the X-axis direction, the above-mentioned translational triaxial force information 7 indicates that only the translational force that contributes to the rotation in the X-axis direction is in the X-axis direction. The rotational force information 23 is obtained. When the selection switch 10 is closed at the switching point 21 for rotation in the Y-axis direction, the translational 3-axis force information 7 indicates that only the translational force that contributes to the rotation in the Y-axis direction is the Y-axis. It becomes the rotational force information 24 in the direction. Further, when the selection switch 10 is closed to the switching point 22 for rotation in the Z-axis direction, the translational triaxial force information 7 indicates that only the translational force that contributes to the rotation in the Z-axis direction is the Z-axis direction. Is the rotational force information 25 at. Any one of these rotational force information is subjected to rotational force coordinate conversion 27, and thereafter, the rotational amount trajectory correction amount 13 is calculated from the target impedance 12 as the rotational force information 11 at the teaching point 6. This trajectory correction amount 13 is sent to the servo controller 16 as a new target trajectory 15 in addition to the original target trajectory 14. The servo controller 16 controls the movement of each actuator of the manipulator body 1 by the output 17 of the servo controller. With the above action, the translational force applied to the force sensor acts as a rotational force applied to the teaching point 6, and a rotational operation in which the manipulator follows this rotational force can be realized.
[0008]
The above switching of the switches is performed by a teacher, and thereby, it is possible to select whether the manipulator performs a teaching operation in the translation direction or a teaching operation along any rotation axis direction.
In the above embodiment, the coordinate system of the force sensor and the teaching coordinate system are arranged in parallel. However, if the axes of each coordinate system are not aligned with each other, the axes may be twisted. In this case, if the coordinate conversion is first performed on the force sensor information, it can be easily configured according to the above embodiment.
As described above, it is possible to provide a teaching force sensor device that has a simple structure and that can measure force information of six axes and that is easy for a teacher to teach by separating translation and rotation teaching operations.
[0009]
【The invention's effect】
As described above, according to the present invention, there is provided a teaching force sensor device that is simple in structure and capable of measuring six-axis force information and that is easy for a teacher to teach by separating translation and rotation teaching operations. There is an effect that can be provided.
[00010]
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of the present invention.
FIG. 2 is a diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Manipulator body 2 Translation 3-axis force sensor 3 Center of force measurement coordinate 4 Force measurement coordinate 5 Teaching point teaching coordinate 6 Teaching point 7 Translation 3-axis force information 8 Changeover switch 9 Force information 10 Selection switch 11 Rotation force information 12 Target Impedance 13 Trajectory correction amount 14 Original target trajectory 15 New target trajectory 16 Servo controller 17 Servo controller output 18 Switching point 19 for translation 19 Switching point 20 for rotation Switching point 21 for rotation in the X axis direction In the Y axis direction Switching point 22 for rotation Switching point 23 for rotation in the Z-axis direction Rotary force information 24 in the X-axis direction Rotary force information 25 in the Y-axis direction Rotary force information 26 in the Z-axis direction Translational force coordinate conversion 27 Rotational force coordinates Conversion 101 Manipulator body 102 6-axis force sensor 103 Teaching point 104 6-axis force information 10 5 Target impedance 106 Trajectory correction amount 107 Original target trajectory 108 New target trajectory 109 Servo controller 110 Output of servo controller

Claims (2)

In a force sensor device for teaching a manipulator by force control using a force sensor ,
The teaching force sensor device comprises:
A translational triaxial force sensor provided on the manipulator hand;
A changeover switch that switches between translational force measurement and rotational force measurement;
A selection switch for selecting one of the measurement directions from the three rotation directions,
A teaching force sensor device characterized in that the coordinate axes of the translational and rotational motions of the manipulator hand and the coordinate axes set in the translational triaxial force sensor are located at positions other than the other coordinate axes. 2. The teaching force sensor device according to claim 1, wherein the coordinate axes of the translational and rotational movements of the manipulator hand and the coordinate axes of the translational triaxial force sensor are arranged in parallel to each other.
[0001]

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