Research On Multi-axis Cooperative Control With Flocking Algorithm

High speed and high precision synchronous control for shaftless driven printing press is always the key technical problems in practical engineering and the hot issues in scientific research. Previous strategies are focus on cross coupling control and electronic virtual line shafting control. However, these methods are limited in the improvement of synchronous accuracy. Therefore, it is significant to research synchronous cooperative control methods for multi-motor system from the new standpoint based on consensus theory and flocking control. This paper considers the shaftless driven printing press as practical engineering backgroung, takes the multi-motor system as the research object. Based on the characteristics of shaftless driven printing press, this paper presents the leader-following method based on flocking control. From the aspects of synchronous cooperative control, real-time synchronous and fault-tolerant control, some indepth researches have done in this paper. The main contributions are the following:By searching and analyzing amounts of research papers, we compare and conclude the previous synchronous control methods, and summarize problems that worth further research. With the inspiration of the former results, we point that multi-motor system synchronous control based on consensus theory and flocking control has great practical and theoretical significance.For the purpose of improving the multi-axis synchronous control precision, we first present a leader-follower method based on flocking control. Specifically, by using parameter optimization method, the system has received a better synchronous performance. This control method not only has the advantages of virtual line shafting control but also introduces flocking intelligence theory. The simulation results demonstrate the effectiveness and superiority of the proposed methodology.In practical engineering, the simplified models are unrealistic, such as single-integrator and double-integrator. And previous algorithms require the acceleration of the leader available to all followers if the leader has a varying velocity, which is also difficult to realize. Therefore, we focus on an observer-based variable structure algorithm for the consensus tracking, which get rid of the leader acceleration. The proposed scheme optimizes tracking and synchronization performance, as well as provides satisfactory robustness.Many existing algorithms can obtain a stable synchronous system, however, the obtained stable system may encounter a large enough disturbance that may destroy the synchronization. Focus on this challenging technological problem, we first propose a state-dependent-switching based leader-following control approach. The convergence and stability of the given multi-motor system are proved. Simulation results have shown that all followers asymptotically converge to a consistent state even when one follower fails to follow the virtual leader during a large enough disturbance, which illustrate good performance of synchronization control accuracy.In the presence of unmeasured angular speed and unknown failures, we investigate a distributed fault-tolerant consensus tracking algorithm for a group non-identical motors. The failures are modeled by nonlinear functions, and sliding mode observer is designed to estimate the angular speed and nonlinear failures. The semi-physical experiments based on RT-LAB real-time simulator further test the system and controller with accurate performance in real-time.