Simultaneous Optimization of a Wheeled Mobile Robot Structure and a Control Parameter

A wheeled mobile mechanism with a passive and/or active linkage mechanism for traveling in the outdoor environment is developed and evaluated. In our previous research, we developed a wheeled mobile robot which has six wheels and a passive linkage mechanism, and its maneuverability was experimentally verified. The ability to climb over a 0.20 [m] high bump, which is twice height of the wheel diameter of 0.10 [m], was achieved, and the mobile robot can climb up continuous steps of 0.15 [m] high. In this research, we optimized the mobile robot linkage mechanisms and a controller parameter by evolutionary algorithm and dynamics engine in numerical simulations. The evolutionary algorithm employed in this research is Genetic Algorithm, and Open Dynamics Engine is used for dynamics calculation. To optimize the linkage mechanism and a controller parameter, we investigated outdoor environment for the mobile robot, for example obstacles, steps, and stairs. And, we selected typical three kinds of outdoor environments, 0.20 [m] high bump, right angle stairs of 0.15 [m] high, and angled stairs of 0.15 [m] high. In the numerical simulations, though the mobile robot using parameters which express our existing robot could climb up/down the 0.20 [m] high bump, but it could not achieve climbing up/down the two kinds of stairs. On the other hand, the optimized parameter mobile robot could climb up/down the three kinds of typical environments.