Error Analysis And Error Compensation Of6-PSS Parallel Robot

Robot is essential to modern society in the product manufacturing. Parallel robotdraws more attention and is widely used due to its character of stiffness, high loadcapacity, speedy response, easy to control and many other prominent merits. Parallelrobot can complete the complex, fine and high strength work instead of human. It notonly improves productivity, but also greatly reduces the labor intensity of workers andimproves the production efficiency. This article take the6-PSS parallel robot which hassix degrees of freedom as a research object focusing on the research of the spacepositioning precision of its end-effector to improve the performance of the parallelrobot.First, this article established a fixed coordinate system and a connected coordinatesystem for the6-PSS parallel robot based on its structural characteristics respectivelyand gives the definitions of all the components and parameters. And then it works atthe inverse kinematics solution based on length formula and simulation by computer. Italso researches on forward kinematics solution with Newton iteration method. Theparallel robot kinematics research provides the theoretical basis for error analysis anderror compensation.Static errors and dynamic errors should be included in the research of parallelrobot error. Static errors are due to the deformation of all the components of theparallel robot, ant it plays a decisive role in the end-effector position accuracy. Thisarticle analyses the static errors by using finite element method. And it comes to theresult of equivalent position-pose errors. The static errors can be alleviated by rationalselection of component materials and optimizing the structure of components.Then the article constructs the vector diagram of parallel robot moving chain withthe space vector sets up a vector equation according to the vector diagram. Influenceeffect of each motion component of the moving chain can be got through the vectordifferential equation. According to this, the processing precision grades parts can bedetermined.Finally this article carries out the study on two different precision grade errorsrespectively considering all the parameters. And it simulates the tow different precisiongrade error with the help of Matlab software and concludes that simple improving theparts processing precision is not an ideal method to reduce the error. In order to fixe end the end-effector errors. This article adopts the method of work space errorcompensation to compensate errors to meet the design requirements.The error of parallel robot end-effector is the key factor that influences theproperties of it. This article succeeded in getting influence degree of all motioncomponents and realizing error compensation. So it guarantees the positioningaccuracy of the6-PSS parallel robots and provides the theory basis for the subsequenttrajectory planning and control strategy. During the research of this subject, the methodpresented in the article is carried out to compensate the error and fulfill the designindicator, which validates the availability of this method.