Speed and torque optimization of a crank-driven wheeled robot in non-impact and vibro-impact regimes

A numerical design study compares a wheeled crank-driven robot in non-impact and compliant-impact operation under common drive-load constraints. Exact slider-crank kinematics, finite link inertia and a unilateral wheel constraint are retained in a coupled model. An energy balance bounds the attainable mean speed, while a constrained search adjusts internal mass, suspension stiffness and damping, crank radius, frequency and clearance. Six root-mean-square torque budgets define numerical approximations of the speed–torque trade-off. At a 0.20 N∙m budget, the best feasible solutions found achieve 0.4433 m/s without impacts and 0.5157 m/s with impacts, a 16.3 % increase. Their peak torques are 0.354 and 0.357 N∙m. However, positive shaft work per distance rises by 8.1 % in the impact solution. Thus, impacts improve attainable speed in the investigated domain without necessarily improving energy economy. The results are computational and conditional on stated contact, resistance and drive assumptions.