Design And Research On Constant Force Control Device For Robot Grinding And Polishing Of Large Components

Large and complex components,such as wind power blades,high-speed rail body-inwhite,and new energy buses,are widely used in China’s energy and transportation fields.With the evolution of China’s manufacturing industry,the use of industrial robots instead of manual grinding of large components has become a key link in the transformation of intelligent manufacturing structures.Currently,in the field of robot grinding and polishing,the pain spot is to control the contact force of robot.This paper designs a constant force control device installed at the end of the robot for the grinding and polishing.It makes new attempts to achieve the conformal fit of the grinding tools during the robot grinding process and keep the contact force constant.The main research works of this paper are as follows:By analyzing the grinding and polishing process model,the effect of the polishing pressure on the material removal rate is theoretically derived.Combined with the actual requirements,the working principle of a constant force device that uses PLC as the control core and adjusts the air pressure through a proportional valve to control the output force of the cylinder is proposed.According to the working principle,the mechanical structure model and electrical circuit design scheme of the device are designed.The gas mass flow model of the system and the device force balance model are established,and the stability analysis of the system is performed from the time domain and the frequency domain.Aiming at the shortcomings of the existing adaptive fuzzy PID control and fuzzy PID hybrid control,a fuzzy PID hierarchical control strategy is proposed and a simulation comparison test is carried out in Matlab.In the TIA portal,the fuzzy PID classification control algorithm and device data collection function are realized by PLC programming,and the host computer interface is written using C #.Build the experimental platform of the prototype of the constant force device.On the basis of completing the calibration experiment,carry out the force control comparison experiment for different control schemes.The experimental results show that the rise time of the system under fuzzy PID classification control is less than 0.2s,the steady-state adjustment time is less than 1.0s,the output force error is within 2N and the output force fluctuation is controlled within 5N in the external force crash test.The constant force device has the functions of automatic stroke compensation and output force adjustment.The control accuracy meets the actual requirements,which verifies the practicability of the constant force control device designed in this paper.