VELOCITIES AND ACCELERATIONS AT THE 3R ROBOTS
The paper presents an original method to determine the velocities and the accelerations at the MP-3R structures. At the 3R structure (spatial) are known (imposed) the angular speeds of actuators and must be determined the velocities and the accelerations of the endeffector point M. Starting from the MP-3R direct kinematic positions system, deriving these relations system in function of the time, one time and then a second time (the second derivation) one obtains first the system velocities, and second time the accelerations of the point endeffector M. The system which must be solved has three equations and three independent parameters to determine. Constructive basis is represented by a robot with three degrees of freedom (a robot with three axes of rotation). If one study (analyzes) an anthropomorphic robot with three axes of rotation (which represents the main movements, absolutely necessary), it already has a base system, on which one can then add other movements (secondary, additional). All calculations were arranged and in the matrix form.