Position-Force Control for a Six Coordinate Industrial Robot when Performing Complicated Surface Treatment

When performing certain technological operations, multi-coordinate industrial robots require simultaneous control of the movement of the executive body and the developed effort. When performing assembly operations (for example, a shaft with a bush), it is necessary to perform a free movement of the shaft along the bore of the bushing and to ensure minimum pressure on the bore walls. When performing operations to handle complex surfaces of parts, it is simultaneously required to move the tool over the surface at a specified speed and to perform a metered pressure on the surface. Since it is impossible to control the force and motion simultaneously at the same coordinate, it is necessary either to switch from one control method to another, or to control various actuators and different controllable coordinates of the actuator. In multi-coordinate robots, this task is complicated by the fact that to control the movement of one of the Cartesian coordinates of the executive body, and by another force, it is simultaneously necessary to control the interrelated generalized coordinates of the robot’s mechanism. In the work presented, the solution of the problem of control of a six-coordinate industrial robot is described, in which the separation of the degrees of mobility into power control and positional control of trajectory motion is carried out. In order to accomplish the task, additional variable parameters are introduced for the treatment of complex surfaces, which determine the position of the cutting edge on the cutting surface, which makes it possible to expand the service area of the robot during selection, for example, one of the coordinates for controlling the pressure force. This task is considered using the example of a six-coordinate industrial robot when performing a complex surface treatment operation, when it is required to program the tool at a specified speed along a path on the surface and at the same time carry out the controlled pressure of the tool on the surface.

position-force control, gas turbine engine (GTE), industrial robot, GTE turbine blade

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