This paper presents a general strategy for manipulator control at kinematic singularities. When a manipulator is an the neighborhood of singular configurations, it is treated as a redundant mechanism in the subspace orthogonal to the singular directions of the end-effector. Control in this subspace is based on operational forces, whale null space joint torques are used to deal with the control ...

In this paper we face the problem of positioning a camera attached to the endeffector of a robotic manipulator so that it gets parallel to a planar object. Such problem, so-called plane-to-plane positioning, has been treated for a long time in visual servoing. Our approach is based on linking to the camera a structured light emitter composed of four parallel laser pointers so that its distribut...

The dynamics and kinematics of a parallel manipulator has been widely researched by virtue of its a high force-to-weight ratio and widespread applications ranging from vehicle or flight simulator to machine tool despite a smaller workspace than a serial robot system (Merlet, 2000). Such a parallel system has been paid special attention as a typical multi-input multi-output nonlinear system to r...

In this papel; a novel spatial three degree-offreedom, that are two degrees of translational freedom and one degree of orientational freedom, parallel manipulator is proposed. The parallel manipulator consists of a base plate, a movable platform, and three non-identical connecting legs. The kinematics problems and velocity equation of the new parallel manipulator are given. Three kincis of sing...

The stiffness of the Exechon hybrid manipulator is a crucial performance indicator as used 5-axis machine tool. Normally, serial module not included in kinematic and analysis. In terms kinematics, parallel modules are said to be decoupled, i.e. can solved for position compensate parasitic orientation platform. This only possible when perfect spherical wrist. However, several models technology h...

In this paper, some definitions and traditional formulas for calculating the mobility of mechanisms are represented, e.g. Grubler formula, Somov - Malyshev formula, and Buchsbaum - Freudenstei. It is discussed that there are certain cases in which they are too ambiguous and incorrect to use. However, a matrix method is suggested based on the rank of the Jacobian of the mechanism and its applica...

A spherical parallel manipulator (also called an orientational parallel manipulator or rotational parallel manipulator) refers to a threedegree-of-freedom (3-DoF) parallel manipulator in which the moving platform undergoes a 3-DoF spherical motion or rotates about a fixed point. In this paper, we propose a new method for the type synthesis of non-overconstrained (isostatic) spherical parallel m...

Dimensional synthesis of a parallel robot may be the initial stage of its design process, which is usually carried out based on a required workspace. Since optimization of the links lengths of the robot for the workspace is usually done, the workspace computation process must be run numerous times. Hence, importance of the efficiency of the algorithm and the CPU time of the workspace computatio...

The large amount of computation necessary for obtaining time optimal solution for moving a manipulator on specified path has made it impossible to introduce an on line time optimal control algorithm. Most of this computational burden is due to calculation of switching points. In this paper a learning algorithm is proposed for finding the switching points. The method, which can be used for both ...

Joint-coupling (JC) is introduced in the design and control of parallel manipulators for managing manipulator singularities. The underlying idea consists of coupling the motions of several manipulator joints by driving the joints with a single actuator. This can be done by mechanical or electronic means, while preserving the mobility of the manipulator. Such JC is intended to alter the direct s...