Reconfigurable Mobile Robot with Adjustable Width and Length: Conceptual Design, Motion Equations and Simulation

In this article, the dynamic equations of a reconfigurable non-holonomic mobile robot used for space explorations and rescue operations are presented. Dimensions of mobile robots usually remain unchanged while they are programmed to determine a new path to bypass obstacles. The aim of developing this robot is to upgrade the mechanical structure so it can adapt its structure to pass the obstacles without path deviation. Furthermore, by means of mentioned reconfigurations, less motor power is needed, leading to optimized energy consumption. To this end, longitudinal and transverse adjustments are defined for the robot. In view of the motion restrictions existing in conventional wheels, omnidirectional wheels are used in robot structure and their features are considered when deriving motion eqs. Accordingly, the robot is able to move in the direction of wheels' axis. To evaluate the designed mechanism, the system is simulated in ADAMS and the results are compared with the derived motion equations. The findings prove that not only is this system implementable, but the results are also consistent with ADAMS with an acceptable error. Additionally, the calculated energy consumption in a robot that uses transverse adjustment to cross obstacles decreases by 12% compared to a robot that climbs the obstacle and 10% decrease occurs compared to path planning method. As the system dynamics are obtained in a general form, the derived equations can be applied in various applications and different configurations.