in recent years, underactuated nonlinear dynamic systems trajectory tracking, such as space robots and manipulators with structural flexibility, has become a major field of interest due to the complexity and high computational load of these systems. hierarchical sliding mode control has been investigated recently for these systems; however, the instability phenomena will possibly occur, especia...

This paper presents the ability of hybrid zero dynamics (HZD) feedback control method to reproduce human like movements for walking push recovery of an under-actuated 3D biped model. The balance recovery controller is implemented on a three-dimensional under-actuated bipedal model subjected to a push disturbance. The biped robot model is considered as a hybrid system with eight degrees of freed...

In this paper we study the dynamics and kinematics of manipulators that have fewer actuators than degrees of freedom. These under{actuated manipulators arise in a number of important applications such as free{ ying space robots, hyper{redundant manipulators, manipulators with structural exibility, etc. In our analysis we decompose such under{actuated manipulators into component active and passi...

in previous researches, mechanical behavior of a microgripper with homogenous and the same material has been studied. in this paper considering the desired characteristics of fgms, as a good thermal and wear resistance, the mechanical behavior of fgm microgripper under dc voltage and temperature variations is investigated. it is assumed that the two microbeams of the fgm microgripper are mounte...

A novel concept called gesture-changeable under-actuated (GCUA) function is proposed to improve the dexterities of traditional under-actuated hands and reduce the control difficulties of dexterous hands. Based on the GCUA function, a new humanoid robot hand, GCUA Hand is designed and manufactured. The GCUA Hand can grasp different objects self-adaptively and change its initial gesture dexterous...

Trajectory of an under-actuated manipulator is usually generated according to both kinematics and dynamics of the manipulator, different to that of conventional manipulator. For this reason, another important problem in trajectory generation for the real system of an under-actuated manipulator is the realizablity of trajectory. That is, the real trajectory by real system may differ greatly from...

this paper presents a robust fractional order controller for flexible-joint electrically driven robots under imperfect transformation of control space. the proposed approach is free from manipulator dynamics, thus free from problems associated with torque control strategy in the design and implementation. as a result, the proposed controller is simple, fast response and superior to the torque c...