Research And Application Of Key Technology Of Constant Force Grinding And Polishing Of Construction

Grinding and polishing,as an important process in the subsequent processing of hardware workpieces,has high requirements for contact force.Constant contact force can effectively reduce the surface roughness of the workpiece and improve the processing quality of the workpiece.Since industrial robots entered the field of hardware grinding and polishing,how to keep the contact force constant during the grinding and polishing process has become a research point.In most constant force grinding and polishing processes,the robot has to perform position control and contact force control,which results in a complex control process and low control accuracy of the robot.In the process of building hardware grinding and polishing,the grinding pressure is high,it is easy to vibrate,and the contact force is more likely to change.As a result,traditional constant force control is difficult to meet the needs of building hardware workpiece grinding and polishing.In order to solve the above problems,this paper separates the robot position control from the force control,and starts the work from two levels.One is to design a follower belt machine with high control accuracy to ensure that the contact force compensation is fast and accurate;the other is to design a fast response.Control stable constant force control algorithm to obtain real-time changes in grinding and polishing pressure.The work done is as follows:(1)Starting from the characteristics of abrasive belt grinding,the force analysis of the abrasive belt dynamic grinding and polishing process is carried out,and then the Hertz contact theory is combined with the Preston formula to establish the material removal depth model under the abrasive belt elastic grinding and polishing;This model is used for simulation,and the influence of the three parameters of grinding and polishing normal pressure,workpiece feed speed,and belt linear speed on the material removal in the abrasive belt grinding and polishing process is quantitatively analyzed through the model.(2)Aiming at the problems of long transmission path,low control accuracy,and insufficient response of the pneumatic constant force grinding and polishing device,a motor-driven method to achieve rapid contact force compensation is proposed,and the principle of this method to achieve constant force control is explained;to ensure contact force compensation The follow-up mechanism has been analyzed for kinematics and displacement deviation,and the key structure design of the follow-up belt machine has been completed;the follow-up belt machine designed for this subject provides a dual vector control method to ensure the grinding The throwing path is more precise.(3)In order to accurately obtain the change of the contact force in the grinding and polishing process,a variable scale chaotic particle swarm algorithm was designed based on the chaotic particle swarm algorithm,and then the mathematical model of the controlled object was established and the fuzzy controller was designed;The scale chaotic particle swarm control algorithm is combined with the fuzzy PID control algorithm,and the variable scale chaotic particle swarm algorithm is used to solve the optimal scale factor for the fuzzy PID algorithm to realize the tuning and optimization of the parameters of the fuzzy PID controller to improve the constant force grinding and polishing system.Response performance and control accuracy.Based on the above work,a constant force grinding and polishing test platform was built,and two experimental schemes for rough grinding and fine grinding were formulated.The grinding and polishing test was carried out with the connecting claws of architectural hardware as the object;the two parameters of depth and surface roughness were removed by grinding.Analyzing the grinding and polishing results,the results show that the constant force control system can better maintain the constant contact force during the grinding and polishing process,and realize the grinding and polishing treatment of the connecting claw.