Kinematic Analysis of a 3- R R P S Manipulator

The paper propose an iterative method for computing the direct kinematic of a 3-RRPS manipulator by considering for each leg a rotary and a linear actuator. It was calculated the error due to difference between the computed mobile triangle vertices and its sides length. To identify the possible angles solutions, it was developed a special function that determine a threshold value applied to the calculated sides of mobile triangle, depending on iteration phases and manipulator dimensional values. The iterations steps lead to refine the range values of ψ angles and its inappropriate values removal. The method can be successfully used for the kinematic analysis of several structure types of legs, by preserving the distance between the connection joints with the fixed and mobile frames.