Optimal Design of a Novel Leg-Based Stair-Climbing Wheelchair Based on the Kinematic Analysis of the Stair Climbing States

This work presents a method to find the optimal configuration of a leg-based stair-climbing wheelchair. This optimization begins with the definition of a high-level control architecture, in which the kinematics restrictions related to the specific obstacles are considered. Then, the reference trajectories for all the actuators are generated as a function of the physical parameters of the mechanism, the dynamic restrictions of the actuators (velocity and acceleration) and the sensor errors. This work illustrates, based on a set of configurations, how the total time to climb up and climb down a defined stair depends on all these parameters, also reporting the best set of parameters that reduces the time and makes the mechanism more stable for a given scenario. The optimization in this work is performed with a brute-force search within a grid of parameters with a resolution of 1 mm. Thus, as the local minima is located, the complexity of the problem is revealed.