Method and device for tracking normal direction and constant force of robot processing operation

Abstract

The invention provides a robot machining work normal constant force tracking method and device. The method comprises the steps that the initial reference track is given; a robot is controlled to movealong the reference track; according to the error between the actual contact force and the expected contact force, iterative computation and updating of the position of the current reference track areconducted; and based on the updated reference track position and the actual contact force direction, the posture of the reference track is calculated. According to the method, the reference track isintroduced into an existing robot machining force control system, the high-precision reference track is obtained through iterative learning and posture estimation, the outline of a machined workpieceand the posture with which a robot machining tool needs to be kept are reflected, machining is conducted according to the reference track, and normal constant force tracking in the machining work process of various curved surfaces can be achieved. Meanwhile, the robot machining work normal constant force tracking method and device can be achieved only through a three-dimensional force sensor, andcost increasing caused by adopting a six-dimensional force sensor is avoided.

Description

technical field [0001] The invention relates to the field of industrial robots, in particular to robot control technology, in particular to a method and device for tracking a normal direction constant force in a robot processing operation. Background technique [0002] At present, the 3C industry has a large demand for robotic grinding, polishing and other applications. Traditional robots use position control, which makes it difficult to maintain a constant contact force during grinding and polishing operations, resulting in uneven processing quality. Therefore, many companies have introduced force sensor-based robotic force-controlled processing solutions. [0003] At present, most of the methods used in force control processing are impedance / admittance control methods (the control block diagram is as follows figure 1 shown). When performing robot processing (grinding, polishing) operations, the contact force and relative position between the robot end tool and the proce...

AI Technical Summary

Problems solved by technology

However, for most processing scenarios, it is difficult to obtain stiffness parameters , so it is difficult to obtain accurate processing trajectory in the end

[0011] In addition, if you want to achieve normal force tracking in processing operations, you usually need to use a 6-dimensional force sensor, which undoubtedly increases production costs

At the same time, due to the friction between the robot end tool and the workpiece, it is difficult to achieve accurate normal tracking

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