Object carrying of hexapod robots with integrated mechanism of leg and arm

Hexapod robots are easy to realize walking in complicated environments and have the characteristic of high redundancy. It is well worth taking advantage of hexapod robots' versatility, such as using legs to do manipulation or carry objects. In this paper, several methods are proposed to deal with issues of carrying objects by transforming one or two legs as arms while walking on other legs for hexapod robots. Firstly, practical gaits for one-legged carrying and two-legged carrying are presented respectively. Secondly, problems existing in gait planning, for instance how to estimate the mass of object and how to calculate joint motions according to desired center of gravity (COG) trajectory, are solved by dynamic analysis and a kinematic method based on COG Jacobian. Finally, the effectiveness of our methods to implement carrying objects is demonstrated by two successful experiments of carrying a bottle of water and a box.