NSGA-II algorithm-based multi-objective optimization method for mechanical arm in redundant space

Abstract

The embodiment of the present invention provides an NSGA-II algorithm-based multi-objective optimization method for a mechanical arm in a redundant space. The method comprises the steps of converting the point-to-point transfer task of the mechanical arm in the operating space from a Cartesian space into a joint space, conducting the parameterized treatment on joint variables based on the sine seven-times polynomial interpolation method, adopting an obtained parameter sequence code as an individual in an NSGA-II algorithm-based population, figuring out an optimized solution for the motion trajectory of the mechanical arm based on the NSGA-II algorithm to enable the sum of the average values of all joint torques to be minimum, the torque of a largest joint to be minimum and the maximum angular velocity of joints to be minimum, and selecting a most optimal solution out of an obtained pareto non-dominated solution set. Based on the above method, the sum of the average values of all joint torques, the torque of the largest joint and the maximum angular velocity of joints are optimized according to the described motion trajectory. According to the technical scheme of the invention, when the point-to-point transfer task is executed in the operating space with the constraint conditions of the task to be met, multiple objects of the mechanical arm can be optimized at the same time according to the above described planning path.

Description

【Technical field】 [0001] The invention relates to automatic control technology, in particular to a multi-objective optimization method for redundant space manipulators based on NSGA-II algorithm. 【Background technique】 [0002] When the end effector of the manipulator moves in the redundancy space, its task space dimension is smaller than its joint space dimension. Therefore, when the end effector of the redundant space manipulator moves according to a certain trajectory, the solution that its joint drive torque meets the task requirements is not unique. It is precisely because of its redundancy that we can optimize its auxiliary performance index under the main motion task. [0003] First of all, it is very important to optimize the joint drive torque of the space manipulator. On the one hand, it is considered from the safety of the working process. If the joint drive torque required by the manipulator is too large or exceeds the limit during the movement, the machine The...

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Problems solved by technology

[0004] When considering the joint drive torque of the space manipulator, we should also pay attention to the joint angular velocity of the manipulator. When the manipulator performs a large load transfer task, if the joint angular velocity is large, it will cause the shake of the manipulator, thereby reducing the task execution accuracy of the manipulator.

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