Adaptive force tracking control method based on iterative learning

Abstract

The invention relates to an adaptive force tracking control method based on iterative learning. The adaptive force tracking control method comprises the following steps that 1, an adaptive dynamic compensation controller is designed according to a regression model; 2, an environment feed-forward force, an environment impedance parameter and a reference trajectory are estimated based on an iterative learning algorithm; 3, a contact model compensation controller is designed according to the estimated environment information; and 4, the adaptive dynamic compensation controller and the contact model compensation controller are superposed to obtain an adaptive force tracking controller required by interaction of a robot and the environment, and adaptive force tracking control is realized. According to the adaptive force tracking control method, the compensation of a nonlinear robot dynamic model can be realized without accurately identifying the robot dynamic parameters, so that the accurate tracking of the reference trajectory is realized, the stable force tracking of the robot to an unknown environment is realized without installing a force sensor, and the method has very high robustness to environment position information and rigidity parameters.

Description

technical field [0001] The invention relates to the field of robots, in particular to an adaptive force tracking control method based on iterative learning, which is especially suitable for force control and force interaction between a robot and an unknown environment. Background technique [0002] Contact with the environment during operation has become one of the important fields of robot application, such as grinding, polishing, assembly and so on. For these tasks, the traditional position control can no longer meet the needs, and a small trajectory error may cause the end of the robot to break away from the contact surface or cause excessive contact force between the end of the robot and the contact surface, resulting in damage to the robot or the workpiece. In order to solve the above problems, the force tracking technology of robots has emerged as the times require, especially the force tracking technology in unstructured environments. [0003] At present, force track...

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Problems solved by technology

However, this method generally estimates unknown environmental information on the basis of prior information, and there are often errors in the identification process, so that a good force tracking control effect cannot be obtained; the second method is to directly adjust the reference trajectory. In order to directly adjust the reference trajectory through prior information

However, this method often produces large force tracking errors because it does not consider the dynamic physical characteristics of the robot end when it is in contact with the environment; the third method is a method of adjusting impedance parameters. Feedback information adjusts the impedance parameters of the robot to achieve force tracking control

However, the stability of this control method is poor, and it is difficult to prove the stability theoretically.

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