| Due to the advantages of high precision,high load,fast dynamic response and easy control,parallel grasping robots have high application value in the field of industry where requiring a large number of repetitive and precise operations.However,the processing technology and procedure are getting more complex,the demand for the degree of freedom of grasping robots is not limited to simple translation operation.Robots that can simultaneously complete the target workpiece grasping and posture adjustment functions have become an important research direction.Based on the above background,a kind of parallel adjustable posture robot,which has good posture space and operation ability,that can quickly and efficiently complete required task is proposed in this paper,corresponding design and analysis are performed.According to the design goals and requirements of the parallel adjustable posture robot,a group of configuration,which meet the required degree of freedom are proposed.After considering the limitations of installation,joint angle and actual control of the robot,the specific configuration of the robot is determined,and the degree of freedom is calculated to verify the correctness of the configuration.The kinematics analysis of the robot,which includes position and velocity is performed.After the correctness of the kinematics is proved through theoretical calculation and simulation,the workspace presented based on kinematics equation,the dimensional influence of each link on the size of workspace is obtained.The static stiffness and dexterity of the robot are analyzed to verify the operation reliability,carrying capacity and moving capacity.Based on the analysis of the motion / force transfer performance,all the singularity configurations of the robot are classified and described.The posture space of the robot is calculated,and the performance index of the posture ability is given.The distribution of the posture ability in the design space is plotted.Optimization has been carried out according to different motion modes of the robot,which let the robot owns maximum posture ability and working space.The Lagrange method is used to complete the dynamic analysis of the robot.Simulation has been carried out through to verify the correctness of the dynamic model.Based on a typical task,two trajectory planning methods are compared among 3-4-5-degree polynomial and sine modified trapezoid using the results of dynamics analysis.Based on the theoretical analysis and simulation results,prototype of the parallel adjustable posture robot is designed and produced,which realizes the movement and operation of the robot under multiple task requirements.The repetitive positioning accuracy of the robot is also analyzed,which verifies the correctness of the robot design and theoretical calculation method. |
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