The paper presents a methodology to enhance the stiffness analysis of serial and parallel manipulators with passive joints. It directly takes into account the loading influence on the manipulator configuration and, consequently, on its Jacobians and Hessians. The main contributions of this paper are the introduction of a non-linear stiffness model for the manipulators with passive joints, a rel...

This paper presents a method to develop minimum energy trajectories for redundant/hyper-redundant manipulators with pre-defined kinematic and dynamic constraints. The optimal trajectory planning uses fifth order B-spline functions to represent the Cartesian coordinates of the end-effector and angles of the redundant links. The actuator torques are considered for the formulation of the cost func...

During the past two decades, parallel manipulator system has become one of the research attentions in robotics. This popularity has been motivated by the fact that parallel manipulators possess some specific advantages over serial manipulators, i.e., higher rigidity and load-carrying capacity, better dynamic performance and a simpler inverse position kinematics, etc. Among various manipulators,...

According to the notation proposed by the International Federation for the Theory of Mechanisms and Machines IFToMM (Ionescu, 2003); a parallel manipulator is a mechanism where the motion of the end-effector, namely the moving or movable platform, is controlled by means of at least two kinematic chains. If each kinematic chain, also known popularly as limb or leg, has a single active joint, the...

A robot satellite with dual-manipulators is one of the choices to operate payload in orbit, for example, to capture or deorbit damaged satellites. We have constructed a ground experiment simulator system including two 7-degree-of-freedom (DOF) manipulators as a chaser satellite model and floating testbeds on a flat floor as target satellite models. This system is a tele-operation ground experim...

This paper presents an original use of Evolutionary Algorithms in order to approximate by a closed form the inverse kinematic model (IKM) of analytical, nonanalytical and general (i.e. with an arbitrary geometry) manipulators. The objective is to provide a fast and general solution to the inverse kinematic problem when it is extensively evaluated as in design processes of manipulators. A mathem...

A 6-DOF 4-4 parallel manipulator is presented. Its forward kinematics can be solved by a sequence of three trilaterations and, as a consequence, its singularities can be described in geometric terms as the degeneration of three tetrahedra. Moreover, it is shown how the proposed manipulator belongs to the family of flagged parallel manipulators. This identification is useful because the topology...

Vibration is one of the most important resources of error in motion of tip of flexible robot manipulators. Although much work has been done in the design of controllers for flexible manipulators to follow a specified tip trajectory, it has been done a little work in trajectory planning itself. For redundant robot manipulators, trajectory planning can be accomplished with the aim of optimizing s...

The main focus of this work is to perform the gravity balancing of a seven degrees-of-freedom (DOFs) hybrid manipulator. A hybrid manipulator is a combination of openand closed-loop chains and contains planar and spatial links. Gravity balancing is an important aspect for robotic manipulators, especially for serial manipulators, where with increase in number of links, the gravitational effect o...

Mechanical structure of a cable-based parallel manipulator consists of a moving platform, witch is called end-effector, and a base. These two elements are connected by multiple cables. Indeed, the end-effector is operated by motors that can extend or retract cables. Cable-based parallel manipulators are structurally similar to parallel ones but they have some advantages, if compared to classica...