Curved surface profile constant force tracking method and application based on non-linear double closed loop control

Abstract

The invention discloses a curved surface profile constant force tracking method based on non-linear double closed loop control, and the method comprises the steps: according to a curved surface profile tracking motion model, force analysis is performed on a model of the contact force between a tool end and a work piece, a relation between an actual motion inclination angle and a normal contact force error and a double closed loop force control method can be obtained through the force analysis and a motion coordinate transformation formula; according to the double closed loop force control method, a control flow of a non-linear PID force controller and a non-linear PID control formula can be obtained, a motion controller can be adopted to control motion of three motion mechanisms in three coordinate directions, so that the tool end can track unknown curve surface profile motion with constant normal contact force. The invention also provides an application device for realizing the method, the device comprises a control part and a mechanical part, the control part comprises a PC host, an embedded motion controller, a terminal board, a signal amplifier, a three-dimensional force sensor, a server driver and a three-coordinate drive and transmission mechanism, and the mechanical part comprises a work rack, movement mechanisms in x, y and z axis directions arranged on the work rack, a sensor clamping rack, a processing tool and a work piece holder for clamping a curved surface part.

Description

technical field [0001] The invention belongs to the technical field of robot processing applications, and relates to an unknown curved surface contour tracking technology, in particular to a curved surface contour constant force tracking method based on nonlinear double closed-loop control and an application device. Background technique [0002] In the existing technology, the on-site application of the surface processing operation of the robot is mainly in the way of teaching and reproduction or offline programming. In this operation mode, the motion trajectory cannot be adjusted according to the shape and position error of the workpiece, the clamping error, and the robot positioning error. , thereby increasing the workload of teaching reproduction and off-line programming, and also reducing the degree of automation of robot processing operations, limiting the application range of robot processing. In robotic applications such as polishing, grinding, deburring, etc., the de...

AI Technical Summary

Problems solved by technology

Although the use of auxiliary devices can increase the flexibility of the robot, its mechanical structure is more complicated; Kazuo Kiguchi [2] In the task of robot tracking workpiece with unknown curved surface, a method of fuzzy force vector is proposed to determine the direction of force control in force / position hybrid control

The fuzzy vector method can determine the range of force control direction, but its accuracy is affected by sensor interference or noise

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