A Synchronous Approach To Trajectory Tracking In Multi-robot Formation Control With Time Delays

Single robots are constrained in practical applications due to their limitedcapacity and expensive costs. Therefore, the multi-robot cooperative systems areattracting increasing attention in the field of robotics recently. In the multi-robotsystems, robots need to communication with each other, thus inevitably producingthe communication delay. The time delay can seriously affect the stability of theperformance. This dissertation aims to develop control methods to deal with thetime-delay problem in formation control.This dissertation presents a synchronization control strategy for the multi-robotformation control with time delays. Because time delays are mainly produced inmutual information communication, a synchronization error is defined withconsideration of communication delays. In the formation process, the robots arerequired to track its trajectory and meet the formation constraints.Firstly, the time-varying path planning model, position error and synchronouserror are defined. To meet the control goal, the decentralized controllers aredesigned to stabilize both position errors and synchronization errors to zero forwhether considering communication delays.Secondly, to verify the effectiveness of the proposed algorithm, the sufficientconditions are derived based on Lyapunov functions, for the cases with and withoutconsidering the time delays. Several simulations, i.e. with and without synchronouscontrol and the synchronization approach with different time delays, are performed.Through the experimental results, it can be seen that the proposed synchronousapproach performs better. When considering the communication delay, the strategycan ensure the convergence of the position error and synchronization error. So therobot can track the desire trajectory and keep the formation during the movements.Finally, the kinematics model of e-puck robot is analyzed and thecommunication between e-puck robot and the host computer was set up. Theexperiments have been performed to verify the effectiveness of the proposedalgorithm.