Design Of Four-Freedom Robot In Stack System And Research On It's Control System Performance

As the most important equipment in modern stacking system, the operating range,stacking-speed and steadibility of the palletizing robot decide performance of whole system. According to the application in the stack system of race sack,the parameters of the palletizing robot as mentioned above are decided.The main research works in this thesis has been summed as following:Firstly, according to the rice-production routine, the whole scheme and parameter of robot have been successfully decided. Secondly, we design the mechanical structure of a four-dimensional cylinder-robot, and choose some key componets. Thirdly, by analyzing the control-characteristics of DC-servo motor,a kind of speed- regulation technology named PWM is used to DC-servo motor,Speed & Electric Current double Closed-Circle Regulating Velocity System and its parameters are decided,the dynamic structure and controlling model are set up. Then, electro-mechanical model for the robot is built,control property is simulated in simulink environment. Moreover, the Position Servo System is designe by using the SISO tool of MATLAB. The superiority of PID ,which is a technology usually used in Position Servo System control,is showed by contrasted with the technology of proportion control.Lastly,on the base of simulation experiment in MATLAB environment,the thesis states briefly the influence of the transmission -system parameter to the performance of the robot's electro-mechanical control property.Based on the design of control system and mechanical structure,the thesis analyzed some factors how to influence the control property of robot.1. By means of analyzing the simulation result of the control system model in MATLAB,we know that the control system response will get rapider if the system gain has gotten bigger . On the other hand,it will cause unstabilty to the control system. So a appropriate system gain must be choosed to keep the control property of control system well.2. According to the simulation result from MATLAB,we analyse the transmission-system parameters of robot,such as rotate-inertia,system rigidity ,damper coefficient and constant load,etc. how to influence the conrol system of Position Servo System, and conclude that rotate-inertia should be reduced to the full in the case that the rigidity of mechanical system can be satisfied,the transmission tolerances must be minimum,and damper coefficient need a right value to ensure a good control property.3. At the final part of the thesis ,by using the nonlinear module provided from MATLAB,we dicuss some nonlinear facts such as friction,backlash,dead zone,act.how to influnce the control property of the Position Servo System, and show clearly some methods to reduce the effect to a minimum.