  This paper presents a nonlinear model predictive control (NMPC) toward
versatile motion generation for the telescopic-wheeled-legged robot Tachyon 3,
the unique hardware structure of which poses challenges in control and motion
planning. We apply the full-centroidal NMPC formulation with dedicated
constraints that can capture the accurate kinematics and dynamics of Tachyon 3.
We have developed a control pipeline that includes an internal state integrator
to apply NMPC to Tachyon 3, the actuators of which employ high-gain
position-controllers. We conducted simulation and hardware experiments on the
perceptive locomotion of Tachyon 3 over structured terrains and demonstrated
that the proposed method can achieve smooth and dynamic motion generation under
harsh physical and environmental constraints.
