Design and testing of double-wishbone suspension for enhanced outdoor maneuver stability of a six-wheeled mobile robot

Ensuring driving stability in wheeled mobile robots (WMRs) within dynamic environments is crucial for reliable navigation. This study presents the design and testing of a double-wishbone suspension (DWS), which is specifically tailored for a highly maneuverable six-WMR configuration, to address stability challenges in unstructured terrains. During the suspension design phase, critical factors such as the link length, position of shock absorber, spring and damping coefficients, and roll center location were optimized using the non-dominated sorting genetic algorithm (NSGA). The proposed DWS module ensures robust and stable driving performance for medium-sized WMRs. It effectively reduces rollovers and external shocks on uneven terrains while maintaining consistent traction across all wheels. Unlike current applications of the DWS in robotics, all the optimized parameters of the DWS with the NSGA algorithm are tailored for high-speed travel and are proficient at absorbing impacts that are encountered during outdoor driving. For practical implementation, a fabricated platform with optimal design parameters was subjected to field tests to evaluate its driving performance, both in prolonged driving on a circular route and in outdoor settings, with bumpy obstacles. The study presents a comprehensive stability analysis of the DWS and the proposed mobile robot, with a specific emphasis on rollover scenarios. The experimental results unequivocally demonstrated that the six-WMR equipped with the proposed DWS outperforms its counterpart without the DWS. This study highlights the reliability of the proposed DWS in the six-WMR configuration for efficient outdoor operations in unstructured terrains.