This paper proposes time-optimal trajectory generation method for industrial robots. The proposed time-optimal trajectory generation method studies the relationship between the maximum acceleration and the maximum velocity, and presents an algorithm for deriving the optimal trajectory based on this relationship. In order to verify this method, a new planar parallel robotic manipulator with fast motion and high precision is designed. Finally, the proposed method is applied to the designed robot, and the simulation results prove that the method is effective for the industrial robot.Index Terms -Time Optimal, Trajectory Generation, Parallel Manipulator I. INTRODUCTION To meet the demands of high-precision and high-speed positioning in advanced manufacturing, many planar parallel robots are applied to industry. To achieve high speed, it is important to enhance the speed of industrial robots to ensure that robots can move as fast as possible at every point in the manipulator space. Therefore, it is very necessary to study the maximum velocity and the maximum acceleration for the trajectory generation method. One method of time-optimal trajectory planning was introduced by Bobrow[1], called as the parameterizing theory. The trajectory scalar variable k was introduced to derive the admissible velocity boundary and the regions in -k phase plane. The theory provided the minimum solution for manipulators with nonlinear dynamics and actuation limits, by parameterizing the path with a single scalar variable. The theory was further improved by Shin and McKay[2]. It was pointed out that admissible regions were not simply connected. The method for connecting admissible regions was also studied. first applied this theory, and solved saturation of the control output(torque) using on-line trajectory. Then, Zlajpah[5] improved this theory in practical application by adding the boundary of joint velocity and task constraints. However, these studies do not cover the derivation and application of the limits of the maximum velocity and the maximum acceleration.It is known that the limits of the maximum acceleration and

This paper introduces a novel 2-DOF high speed and high precision planar parallel manipulator. The manipulator consists of a moving platform that is connected to a fixed base by two limbs. Each limb is made up of one prismatic and four revolute joints and the two prismatic axes are arranged orthogonally. In contrast to conventional XY-tables, the manipulator investigated herein doesn't need decoupling structure. In this paper, firstly, the optimal configuration of the manipulator is obtained based on the condition number. Secondly, for the optimal configuration, the forward and inverse kinematic equations are derived, and the singularity of the manipulator is analysed. Then, the optimal shape and position of workspace is obtained based on the global performance index. Finally, the dimension optimization design is performed according to the optimization objective function, which considers the global condition index and workspace.Index Terms -Planar parallel mechanism. High speed and high precision. Optimal kinematics design.