Mechanical analysis of parallel manipulators with simulation, design and control applications

摘要

The kinematics and dynamics for the purposes of analysis, control, simulation, and design of general platform-type parallel manipulators are the subject of this thesis. Two new methods of direct kinematics for displacement analysis are proposed. Velocity and acceleration analyses for general kinematic architectures are fully studied. Furthermore, kinematic singularities are classified based on their nature. Architecture singularities and architecture conditioning are deeply studied and incorporated into design strategies, along with design examples. Moreover, formulation singularities are also given due attention with case studies. In dynamics modelling, the method of the natural orthogonal complement is applied such that the resulting models are structurally algorithmic, computationally efficient, and numerically robust--essential properties for the implementation of more sophisticated control strategies. Efficient inverse and direct dynamics algorithms are developed based on the dynamics models in both joint space and Cartesian space. The algorithms have been implemented with a general software package that is available for dynamics control and motion simulation of platform manipulators. As practical applications, the dynamics modelling and simulation of some commercial flight simulators are included. Finally, the concept of dynamic isotropy is introduced, which allows one to evaluate the motion/force performance of a manipulator with respect to control and simulation. Application strategies of this concept to some robotics problems such as design, trajectory planning, and inverse kinematics are discussed, along with examples.