Consistency optimal coordination control of underground heavy-load robot in nonstructural environment

Abstract

In order to guarantee the dynamic stability of robots in nonstructural environment, this paper proposes a new consistency optimal coordination (COC) control strategy. Firstly, by analyzing the topological structure, motion correlation and control coupling relationship among subsystems, the general expression of multi-body coupling system (MCS) for underground heavy-load robot is realized. Then, the transient spatial output deviations are proposed as the characterization of dynamic stability for the underground heavy-load robot. Afterwards, in order to reduce the strong coupling relationship among subsystems, the underground heavy-load robot is decoupled into fixed-point and non-fixed-point operation modes, the Nyquist stability and Lyapunov stability are applied to discriminate the dynamic stability of two working modes respectively. Finally, based on the idea of minimum loop gain compensation of mechanism, the COC control strategy is proposed, which can coordinate the subsystems to be consistent, so as to realize the dynamic stability of overall system in nonstructural environment. Both the experimental and situational results verify that the COC control strategy proposed in this paper not only realizes stable output of robot, but also effectively reduces the lag caused by instability. The work of this paper improves the dynamic stability analysis theory for robots, and promotes adaptability and dynamic response capability of moving robots as well.