Six-degree-of-freedom robot force control method for unknown environment

Abstract

The invention discloses a six-degree-of-freedom robot force control method for an unknown environment and belongs to the field of compliance control of robot motion. The method comprises the followingspecific steps: firstly, acquiring zero data of a force sensor, the gravity of a robot wrist tool and barycentric coordinates, and determining true force and moment generated when the robot wrist tool is in contact with the environment; secondly, determining the position control direction and the force control direction of the movement of the tail end of the robot according to the true force andthe moment generated when the wrist tool of the robot is in contact with the environment; and finally, acquiring a reference trajectory of robot motion, determining an impedance control model, and completing force control operation of the robot. According to the invention, the measurement precision of the force sensor is improved through the on-line calibration of the force sensor, accurate forceperception information is provided for the force control operation of the robot, the impedance control strategy is adopted to control the motion trail of the robot, the conversion between force control and position control is stable, and the adaptability and robustness are better.

Description

technical field [0001] The invention discloses a six-degree-of-freedom robot force control method facing an unknown environment, which belongs to the field of soft control of robot motion. Background technique [0002] At present, the operation mode of industrial robots is mainly based on position-based motion control, which lacks the control of contact force during the operation process. In order to better complete tasks such as grinding and polishing, constant force tracking, and precision assembly, it is necessary to communicate between the robot and the contact environment. The ability to have strong control. [0003] By installing a six-dimensional force sensor at the end of the robot, the robot has the ability to sense force, and the contact force control between the robot and the external environment is realized through the acquired force information. However, in the actual working process of the force sensor, the force sensor needs to be considered. Measurement erro...

AI Technical Summary

Problems solved by technology

The force / position hybrid control sets the robot in position control mode on some degrees of freedom and in force control mode on other degrees of freedom, but this control method must establish precise environmental constraint equations to achieve a definite Jacobian matrix and Calculate the coordinate system, and determine the direction of the force and position by responding to the selection matrix required by the task in real time, so the force / position hybrid control is difficult to achieve force control tasks in an unknown environment

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