Design And Analysis On Pick-and-place Mechanism Based On Approximate Lamé Curves

The 'pick-and-place' action on the target workpiece is one of the most common actions in the automated assembly line. It can meet the requirement of sorting, handling and assembly process. The related equipment is essential to reduce the cost of production, improve the working efficiency and productions of device. In order to solve the problem that the automation equipment technology backward and high cost of using industrial robots to picking and discharging, this paper proposes a picking mechanism of approximate Lame curve trajectory around the pick and place operation trajectory, then, optimized and analyzed the character of mechanism, finally, processing and testing the prototype. The main contents and results of the paper are as follows.1.Analyzed the research status of the 'pick and place' manipulator in domestic and overseas, compared the advantages and shortages of the existing pick and place equipment,and summarizes some problems in the application of 'pick and place' operation technology.Combined with the current production needs of enterprises in China, and determined the main content and technical lines of this study.2. According to the design requirements, indicators and working conditions, analyzed the working requirement of 'pick and place' operation, such as the space of 'pick and place'operation, pickup height, the technical requirements and action characteristics of implementation action, to finish motion constraint analysis of the action attitude and mathematical description of trajectory. Analyzed the kinematic characteristics of mechanism motion process in different transition curves, and determined the similar Lame curve trajectory to improve the comprehensive performance of the equipment.3. Designed a normal speed motor driving picking mechanism with approximation Lame curve trajectory and simple structure. Described the operating principle of the 'pick and place'mechanism in detail, and established the mathematical model of it. Analyzed the kinematics and the dynamic characteristics of the mechanism, and the influencing factors of the output trajectories of the components.4. Using micro-genetic algorithm to optimize the dimensions of the 'pick and place'mechanism, and finished the auxiliary optimization software based on Matlab 2010. The key mechanism are optimized for the length of the terminal rod, the length of the connecting rod,the length of the crank rod and the gear ratio of the internal gear. According to the optimization results,a 3D model of the picking mechanism with approximate Lame curve trajectory is established, and the driving torque required for the operation of the mechanism is obtained by Adams simulation.5. Completed the design and processing of the test prototype. The actual trajectory of the prototype is captured by Phantom v₅.1 high speed camera, and it is compared with the theoretical trajectory and the trajectory of virtual simulation prototype, the results showed that three trajectories basic consistent, so the accuracy of the design is verified. AVANT MI-7008 data acquisition and analysis system was used to evaluate the indoor kinematic characteristic and acceleration value of each test point, and the acceleration sensor was installed at the end-effector. The test results show that the 'pick and place' operation mechanism designed by this method can support for sorting, handling and assembly robot technique and greatly reduce the cost of equipment.