Control method of anti-interference electric six-degree-of-freedom parallel mechanism

Abstract

The invention discloses a control method of an anti-interference electric six-degree-of-freedom parallel mechanism. The method comprises the steps: firstly, aiming at the characteristics of nonlinearity, strong coupling and the like of the electric six-degree-of-freedom parallel mechanism, establishing a mathematical model of the mechanism, and designing a cascade control model based on a linear actuator hinge space and a motion platform attitude space, wherein control based on the hinge space is taken as an inner ring, control based on the motion platform attitude space is taken as an outer ring, and the inner ring and the outer ring adopt PID controllers. Aiming at the characteristics that the load torque of a single linear actuator of the six-degree-of-freedom parallel mechanism is changed in real time and the control precision is influenced, the angular acceleration information of the actuator is acquired by adopting a state observer, and an anti-interference compensation controller is designed on the basis, so that the influence of disturbance on the control precision is eliminated; and finally, a Ziller-Nichols PID parameter setting method is applied to obtain an optimal PIDcontrol parameter. The control effect of the method on the electric six-degree-of-freedom parallel mechanism is superior to the control effect of a traditional PID method based on the hinge space.

Description

technical field [0001] The invention belongs to the field of system automatic control, in particular to an anti-interference electric six-degree-of-freedom parallel mechanism control method. Background technique [0002] In recent years, the control algorithm of the six-degree-of-freedom parallel mechanism has become one of the research hotspots at home and abroad. As a branch of industrial robots, the six-degree-of-freedom parallel mechanism is widely used in Ships, aviation, electric power, vehicles and other military and civilian fields have extremely broad application prospects. The six-degree-of-freedom parallel mechanism is a complex system characterized by nonlinearity, strong coupling and static instability, and it is difficult to achieve efficient and stable control of it. At the same time, due to the transformation of the load and its own motion characteristics, the load of each linear actuator changes in real time, and its change characteristics are difficult to ...

AI Technical Summary

Problems solved by technology

The six-degree-of-freedom parallel mechanism is a complex system characterized by nonlinearity, strong coupling, and static instability, and it is difficult to achieve efficient and stable control of it

For each electric servo system, its load characteristics change at any time with the change of the pose of the moving platform. In the process of designing the control system, this load characteristic is equivalent to the equivalent disturbance force and the equivalent Mass, however, when the moving platform of the six-DOF parallel mechanism is in different poses, the equivalent mass changes greatly, and the equivalent disturbance force also changes greatly. The system controller designed in this way is obviously conservative , can only be adapted to occasions with low performance requirements

On the basis of comprehensive consideration of the system dynamics characteristics and the dynamic performance of each channel, the latter adopts the control strategy based on the system dynamics model to design the controller, which can improve the overall performance of the system, but when the load has time-varying characteristics, its control effect Not obvious, and modeling is difficult and computationally intensive

Images