Slip considered path planning of a novel angled-spoke based robot in a terrain mixture of granular media and rigid support.

Navigation in terrains mixture of rigid support and granular media is associated with slippage. It is important to find the optimal path because slippage implies the possibility of a mobile robot being stuck in the sand. This research introduce concept of effective distance which consider effect of slippage to present a path planning algorithm. Effective distance is a conceptual distance that the mobile robot traverse to reach next node, and it is calculated based on traversable difficulty. Traversable difficulty varies with the slope angle, and the revolution speed of the angled spoke-based wheel (ASW) is estimated using meta-model. The meta-model is achieved empirically. Experiments have done in testbench which can implement slope angle and terrain types. Effectiveness of this algorithm was verified through simulation. For the simulations three cost determination methods, namely, the effective distance with varying revolution speed of the ASW, the effective distance with fixed revolution speed of the ASW, and actual distance were examined in four different scenarios. The effective distance with varying revolution speed of the ASW has maximum [Formula: see text] longer total actual distance. However, it results minimum [Formula: see text] shorter total effective distance.

Design optimization of a linkage-based 2-DOF wheel mechanism for stable step climbing.

This paper presents the design optimization of a linkage-based wheel mechanism with two degrees of freedom, for stable step climbing. The mechanism has seven rotational joints and one prismatic joint. Kinematic and dynamic analyses of the mechanism were performed. The design was optimized in terms of linkage length and architecture to better manipulate the mechanism in its workspace, which was defined here by the targeted step size, as well as to ensure stability while climbing stairs. Optimization by genetic algorithm was performed using MATLAB. The optimized mechanism exhibited enhanced torque transmission from the input torque to the exerted for at the lobe of the wheel. Compliance control of the transformation will be addressed in the future.