Stable under-actuated manipulator design for mobile manipulating Unmanned Aerial Vehicle (MM-UAV)

The use of manipulator on quadrotor is highly restricted due to expected arising instability problems. This paper investigates a new approach in designing manipulators mounted on quadrotors that ensures maintaining maximum MM-UAV stability. In this approach, an algorithm is used to predict the payload's mass variation that results from catching or releasing objects. The ability of the manipulator to preserve the quadrotor stability is verified by simulation. The results of the study reveal that the manipulator can move while ensuring the stability of the quadrotor. This approach ensures that the resulting shift in the quadrotor center of gravity (CoG) does not exceed 0.5 mm at a specific payload mass in the steady state. The results also show that the reaction torque on the quadrotor which is caused by the manipulator's movement is approximately zero in the steady state.