A study on a flexible mobile robot with versatile shape control based on multiple link-wheel mechanism. 2nd report Joint load distribution control method for attitude control subjected to shape constraints given to a moving module.

Based on a previous paper, an attitude control method of the Vroid is dealt with here, under some conditions, so that some of the modules should satisfy the constraints for the robotic shape and attitude, since it is sometimes required that mobile robots must carry something and/or liquid containers in a restricted moving mode. The assumptions are that (i) the Vroid has six degrees-of-freedom, including the freedoms of the rotational joint of the first link and the moving wheels, which were not treated in the previous paper ; (ii) the central link must be kept in the horizontal position as a constraint, which yields five degrees-of-freedom in Vroid ; (iii) Vroid moves along a slope. The problem is formulated as a linear programming problem minimizing the total applied moments at joints, subjected to constraints. Then the proposed control method gives a solutions for the control sequence of the Vroid for various terrains.