Master of Engineering (Hons.)
Department of Mechanical Engineering
Fang, Yijiang, A study of multi-rigid-body dynamics: an application to robotic manipulators, Master of Engineering (Hons.) thesis, Department of Mechanical Engineering, University of Wollongong, 1995. http://ro.uow.edu.au/theses/2509
In this dissertation, a general computer-oriented dynamical model for a serial robot manipulator is built based on D'Alembert's principle. The dynamical equations are derived on the basis of multi-rigid-body system according to structural characteristics of the serial robot manipulators. The equations are vectorial and completely recursive, and are suitable for a serial manipulator in general with revolute and/or prismatic joints. Then, on the basis of the general dynamical equations obtained, an efficient recursive approach for the computer generation of a manipulator dynamical model is presented. It suits the direct or inverse problems of dynamics: The direct problem is that joint accelerations are computed from actuator forces; The inverse problem is that actuator forces are computed from joint displacements, velocities and accelerations. The method presented is a computer-oriented dynamical modelling method that forms and solves dynamics equations automatically. These dynamical equations obtained are succinct in form and compact in structure. Furthermore, the augmented body, defined as a fictitious body composed of link i and the mass of link i+1 through n attached at joint Oi+i, and composite system, defined as a body composed of link i through n, in the model for a serial robot arm are used. The recursive formulae corresponding to the augmented body and composite systems are set up, which make the dynamics computation simple and raise the computational efficiency. These formulae are very simple and straightforward, and can be used for solving the direct and inverse problem of dynamics. On the basis of the dynamical model presented in this dissertation, we derived specific computational formulae and compiled general computer programs. In addition, a PUMA robot is taken as an example to illustrate the method on an IBM PC.