A novel approach for modeling and tracking control of a passive-wheel snake robot

This article proposed a novel approach for the dynamic modeling and controller design of a passive-wheel snake robot based on Udwadia-Kalaba theory. Compared to common methods, this approach is easily processed for many-degree-of-freedom snake robot. The desired trajectory is easily modeled as a trajectory constraint, and the nonholonomic constraints from the passive wheels' lateral velocity are also easily handled using Udwadia-Kalaba theory. Besides the proposed equation of motion is analytical, no approximation or linearization as well as extra variables such as Lagrangian multiplier is needed as common methods usually do. The servo joint constraint forces are precisely calculated by solving Udwadia-Kalaba equation, and no complicated control structure design is needed as common control methods always do especially for under-actuated mechanical systems. This article provides a novel dynamic modeling and controller design approach for the passive-wheel snake robot in a new perspective. The theoretical analysis and simulation verify the proposed approach. The trajectory has good incidence with the designed one, and the real-time joint forces are also conveniently acquired.