5.3 Control of the robot standing on stable and vibrating ground

In this subsection, we considered the control problem of the robot, which is standing on vibrating ground. As in previous subsection, to better illustrate the process of controlling individual legs of the robot, we also assumed that ΔxRðÞ¼ t ΔyRðÞ¼ t ΔzRðÞ¼ t 0 and αRðÞ¼ t βRðÞ¼ t γRðÞ¼ t 0 (i.e., full, both linear and angular, spatial stabilization of the robot's trunk). In turn, we have taken non-zero harmonic excitations of the ground, i.e., ΔxGð Þt 6¼ 0, ΔyGð Þt 6¼ 0, ΔzGð Þt 6¼ 0, and αGð Þt 6¼ 0, βGð Þt 6¼ 0, γGð Þt 6¼ 0. Simulation results captured in regular time intervals are presented in Figure 6. As can be seen, as in previous cases, in each time the robot is supported by all eight legs, thanks to the appropriate changing of the configurations of its all legs, depending on the vibrating ground. As a result, the robot keeps its position and orientation in the global coordinate system, regardless of the vibrating ground, also increasing its stability. The presented control algorithm also works for ΔxRð Þt , ΔyRð Þt , ΔzRð Þt 6¼ 0 and αRð Þt , βRð Þt , γRð Þt 6¼ 0. As a result, the considered construction can play a role of a mobile Stewart platform also on vibrating ground.

On the Controlling of Multi-Legged Walking Robots on Stable and Unstable Ground DOI: http://dx.doi.org/10.5772/intechopen.90208

Figure 6. Configurations of the investigated hybrid octopod robot on vibrating ground, captured in regular time intervals.
