SUMMARYWalking with a maximum speed is an interesting subject in the field of biped motion. Giving an answer to the question of “what is the maximum achievable speed of a certain biped walking with a physically acceptable pattern?” is the main objective of this work. In this paper, minimum time motion of biped was studied during one step that consists of single support phase (SSP) and double support phase (DSP). The minimum time problem is formulated with stability and non-slip conditions along with actuator limits expressed as some inequality constraints. In addition, certain kinematic constraints in terms of hip joint position are considered that ensure an acceptable walking pattern. A phase-plane technique is used to find the minimum time solution. A numerical simulation is given to shed some light on how the proposed method works. Validity and effectiveness of the method are verified by comparing the results with those of other researches.

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Grasping and handling delicate objects with robotic systems could be done by force closure method which needs a sophisticated control capable of providing stable grasping of the object with minimum possible normal force. It is a common practice among researchers to simplify dynamic of system by assumpssions such as permanent contact or incipient slip condition between object and gripper. Although such assumptions might be good in general grasping problem, where applying large contact forces is permissible, they are not valid in the case of safe grasping in which the contact forces should be minimal. This paper presents a new controller inspired by human method of grasping. The proposed controller, which only needs measurement of the contact forces, is then employed in conjunction with jacobian transpose method for grasping by multi-link fingers. Versatility of proposed algorithm is shown by means of several numerical examples as well as analytical developments.A 978-1-4244-4775-6/09/$25.00