Our long-term goal is one of designing land-based vehicles to provide enhanced uneventerrain locomotion capabilities. In this research, we examine and evaluate candidate articulated legwheel subsystem designs for use in such vehicle systems.

The leg-wheel subsystem designs under consideration consist of disk wheels attached to the chassis through an articulated linkage containing multiple lower-pair joints. Our emphasis is on creating a design that permits the greatest motion flexibility between the chassis and wheel while maintaining the smallest degree-of-freedom (d.o.f.) within the articulated chain. We focus our attention on achieving two goals: (i) obtaining adequate ground clearance by designing the desired/feasible motions of the wheel axle, relative to the chassis, using methods from kinematic synthesis; and (ii) reducing overall actuation requirements by a judicious mix of structural equilibration design and spring assist.

This process is examined in detail in the context of two candidate single-degree-of-freedom designs for the articulated-leg-wheel subsystems ¨C a coupled-serial-chain configuration and a four-bar-configuration. We considered the design synthesis of planar variants of the two candidate designs surmounting a representative obstacle profile while supporting a set of end-effector loads and highlight the key benefits in the presented results.