In the control of robot manipulators, it is customary to assume that the eigenvalues of the inertia matrix are uniformly bounded from below and above. However, in this article it is shown that not all manipulators possess this property. The class of serial robot manipulators with bounded inertia matrix, referred to as class B D manipulators, is completely characterized and it is shown that it i...

Certain high speed industrial assembly robots share a peculiar three legged parallel architecture wherein three “hips”, attached to a fixed upper base or “pelvis”, actuate “thighs” connected by “knees” to “shins”. Each shin is a parallelogramic four-bar linkage. “Ankles” are connected to a common end effector “foot” which executes spatial translatory motion. Inverse and direct kinematic analyse...

Taking a spatial parallel robot with flexible joints and links as the research object, dynamic modeling method for multi-flexible-body system is proposed. Its effectiveness verified by comparing numerical model simulation model. (1) Background: The elastic deformation of in under high-speed operation coupling effect between rigid components substantially affect stability trajectory accuracy. Th...

A desired dynamic behavior of constrained manipulators can be achieved by means of impedance control and various implementations of fixed controllers have been proposed. In this paper, and adaptive implementation is presented as an alternative to reduce the design sensitivity due to manipulator mismatch. The adaptive controller globally achieves the impedance objective for the nonlinear dynamic...

Placement of robotics manipulators involves the specification of the position and orientation of the base with respect to a predefined work environment. A general approach to the placement of manipulators based on the kinematic dexterity of mechanisms is presented. In many robotic implementations, it is necessary to carefully plan the layout of the workplace, whether on the manufacturing floor ...

In this article, the authors investigate the fault tolerance of manipulators in their nominal configuration. In this work, fault tolerance is measured in terms of the worst case relative manipulability index. While this approach is applicable to both serial and parallel mechanisms, it is especially applicable to parallel mechanisms with a limited workspace. It is first shown that the relative m...

This thesis deals with the kinematic analysis, dynamic analysis and static balancing of planar and spatial parallel mechanisms or manipulators with revolute actuators. The inverse kinematics of each mechanism is first computed and a nengeneral algorithm is used to locate the boundaries of the workspace of the mechanism. Two approaches. narnely. the algebraic formulation and the vector formulati...

A current trend in Robotics is the analysis and the design of cooperative manipulation system, i.e. systems composed of multiple manipulator units interacting one another in a coordinated way. A cooperative system is characterized by higher manipulability and load capacity with respect to single-manipulator systems. The concept of the relative Jacobian is used to generate trajectories in the jo...