Speed control method for high-accuracy traction teaching robot based on impedance model

Abstract

The invention discloses a speed control method for a high-accuracy traction teaching robot based on an impedance model. The speed control method includes the steps: S1 acquiring information of a six-dimensional force sensor by the robot: firstly, performing filter processing for acquired information, secondly, performing gravity compensation, and finally, acquiring deviation data of expected force or an expected torque value; S2, transforming the deviation data of the force or the deviation data of the torque value into moving speed of the tail end of the robot in the Cartesian space and angle speed rotating around an axis according to the impedance model; S3 performing smooth interpolation for motion according to a deformed S-shaped speed control curve to obtain a corresponding position function, a speed function and an acceleration function; S4 calculating a joint angle function in joint space according to inverse kinematics; S5 performing isochronous interpolation of the joint space for the joint angle function, and transmitting the joint angle function to a servo driver by a bus of a controller to control actions of the robot. According to the speed control method, traction accuracy is effectively improved.

Description

Technical field [0001] The invention relates to the field of industrial robots, in particular to a speed control method for a high-precision traction teaching robot based on an impedance model. Background technique [0002] Manually towing the teaching robot operation is an indispensable part of human-machine collaboration. It is the operation of instructing the teaching staff to drag the robot to the teaching point in Cartesian space or joint space. During traction and teaching, the end or joint of the robot needs to track the intended direction of human dragging in real time and accurately, and enable the robot to make the desired motion state. There are two intuitive solutions for traditional traction teaching robots: Admittance control based on the secondary development interface of the existing controller or zero-force drag teaching based on torque mode without torque sensor. However, these two solutions have the following shortcomings: ①Due to the low level of interface de...

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Problems solved by technology

However, these two solutions have the following disadvantages: ①Due to the low level of interface development, only some interface functions are available, such as point-to-point motion commands (MovJ or MoveL), which cannot control the speed and acceleration of the robot during motion ;②Based on the existing secondary development interface of the controller, only the relationship between the force deviation F and the displacement x can be established. Therefore, in each force control cycle, the end of the robot will experience "acceleration-uniform speed-deceleration" or "acceleration- Therefore, it will be found that the movement of the end of the robot is not smooth during traction, and the traction effect shows that the real-time traction effect is poor and the traction accuracy is low.

③The drag teaching based on zero-force control without torque sensor has low traction accuracy and needs to rely on an accurate dynamic model. Moreover, when dragging at low speeds, there are many nonlinear factors that affect the accuracy of dragging. It is difficult to achieve accurate traction teaching without a torque sensor, so it is also difficult to use in actual industrial sites

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