Research On Trajectory Planning Algorithm Of6R Serial Robot

Trajectory planning of the robot is the foundation of motion control, and it affects the stability and reliability of the robot control system directly. A rational trajectory planning algorithm can make the robot arrive at the designated location fast, smoothly and accuracy, while it also the fundamental to machine the parts with complex curves and surfaces. Therefore, to study the trajectory planning robot has important practical and theoretical significance. In this paper, the trajectory planning algorithm of6R series robot is studied in Cartesian space, which combined double quaternion representation of spatial displacement with Bezier curve. The main research contents and results are as follows:1Double quaternion was applied to describe the position and orientation in Cartesian space. Based on the relationship of double quaternion with displacement, the position and orientation of robot’s arm can be expressed by double quaternion respectively, while the position and attitude of the robot’s arm can also be expressed by double quaternion in a unified form. The one-one corresponding relationship of three-dimensional position and orientation points and double quaternion was established in this paper.2The trajectory curve of the robot arm was described by double quaternion and Bezier curve. Base on the quaternion spherical linear interpolation and Bezier interpolation theory, a continuous smooth double quaternion curve was designed, which is trajectory curve of the robot arm. According to conversion relationship between double quaternion and homogeneous matrix, the position and orientation of discrete points was get in Cartesian space, which must meet the positioning accuracy. Using the kinematics inverse of the robot, a sequence of joint position was obtained, and the joint position is the data to set into the servo controller. Above all, the servo drive position poses of the manipulator to achieve the smooth adjustment in Cartesian space.3Based on Mathematica which is an mathematical software, the trajectory planning studied in this paper was simulated to achieve dynamic simulation of three-dimensional curves of6R serial robot. In this simulation, the operation was simulated and the image of running track was showed.In summary, the trajectory planning basing on double quaternion and Bezier curve was used to describe the interpolation of the position and orientation in space with a uniform method, while interpolation of the position and orientation can also be described respectively. This method provide a new posture planning solutions for the trajectory planning of robot.