First and second order influence coefficient expressions of 3-RPS parallel mechanism are deduced by using the loop equation method.Based on the first and second order influence coefficient

the inverse kinematics problem is researched.The kinematics model of 3-RPS parallel mechanism is built based on the influence coefficient.The model is simulated by using Matlab.The characteristics of first and second order influence coefficient are obtained by analyzing drive displacement

velocity and acceleration curve.The first and second order influence coefficients of 3-RPS parallel mechanism are independence to the motion of driving link and only relate to its kinematic size

type and location.