Research On Active Compliance Grinding With Constant Force Control Technology For Polishing Complex Curved Surfaces

In the aerospace,automotive,and other industries,the problem of complex surface grinding is often encountered.The shape of complex surfaces is highly variable and difficult to model geometrically and plan machining paths.During grinding,the contact area between the grinding wheel and the workpiece is small,and even slight changes in pressure can result in surface defects.Therefore,to solve these problems,efficient grinding methods and technologies need to be adopted,and computer simulation and control technology need to be used to improve machining efficiency and accuracy.Complex surface grinding constant force control technology refers to the use of a constant force control system in the surface grinding process of a complex surface,which controls the relative position and machining force between the tool and the workpiece to achieve highquality and efficient grinding.This technology requires higher control accuracy and machining accuracy than traditional grinding,and more complex sensors and control algorithms need to be used,but related research is limited.In response to this situation,this paper studies the complex surface grinding constant force control technology by installing an active compliant device on the grinding mechanism,aiming to ensure the surface quality of complex surface workpieces while improving grinding production efficiency.Firstly,a control strategy combining fuzzy control and PID control was designed,and the feasibility of the control strategy was verified through comparative simulation of classical PID and fuzzy PID control strategies.Then,control response verification experiments based on the grinding test platform were carried out for various control strategies.Finally,based on different process parameters,the surface roughness of complex surface blades was measured and verified,further verifying the feasibility of the control strategy.The entire research content is as follows:Firstly,the design requirements of the active compliant device on the grinding mechanism were analyzed,and the design content of the active compliant device was determined.The selection and design of various control components and acquisition components were carried out,and the system control structure diagram was designed.Then,the system mathematical model was derived,and system model identification experiments were carried out to obtain the optimal system identification model,and stability analysis of the identification system was conducted.Next,the optimal PID parameters were obtained through the Ziegler-Nichols empirical formula method and Matlab/Simulink parameter tuning panel.The fuzzy PID controller was designed based on the principle of combining fuzzy control and PID control,and compared with classical PID control through response simulation.The simulation results show that the fuzzy PID control strategy has better constant force control characteristics for grinding than classical PID control strategy.Finally,the grinding test platform was built,and grinding experiments of complex surface blades based on constant force control strategy were carried out to further verify the constant force control advantages of fuzzy PID control strategy.Surface roughness tests of complex surface blades under different process parameters were conducted using the fuzzy PID control strategy.The experiments show that the surface roughness of complex surface blades under this control technology can meet the requirements of engineering applications.