Research On The Key Technology Of Haptic-integrated Robot Virtual Teaching For Belt Grinding

Abrasive belt grinding is widely used for the finishing of complex parts due to its flexible machining characteristics and low processing cost.The grinding paths are usually defined through online teaching or off-line programming to achieve automatic process.However,the traditional robot programming method can neither provide the haptic interactive function nor realize the simulation of the flexible machining process.Therefore,it is difficult to control of the grinding force in the teaching process,which greatly reduces the toolpath's accuracy and the programming efficiency.Based on virtual reality and haptic feedback technology,this paper developed a virtual robot teaching system for belt grinding,which focuses on the precise modeling and simulation technology of the grinding force and the deformable abrasive belt in the virtual teaching process.The main work contents are as follows:(1)For the contact-wheel belt grinding process,firstly,the grinding principle and the influence factors of grinding force are analyzed.Then,the contact geometry between complex parts and contact wheels are studied,and an elliptical contact and a rectangular contact model are established.Finally,based on the different grinding stages,a phased grinding force model is proposed to realize the real and continuous force feedback in the virtual teaching process.(2)For the freestyle belt grinding that grinding with the elastic abrasive belt,firstly,the common modeling methods for deformable objects are analyzed,and the mass spring model is selected as the modeling method for elastic belt.Then,the basic mechanical properties of the abrasive belt are studied and analyzed,and a calculation method of the spring force is put forward by integrating the stress-strain properties of abrasive belt.Finally,based the force analysis of workpiece and spring mass,a force model in freestyle belt grinding is put forward.(3)A haptic-integrated virtual robot teaching prototype system for belt grinding is designed and implemented.Based on the system,the experimental research of the grinding force model and the deformable belt model are carried out.Finally,a case study for the teaching of the welding door handle is carried out to evaluate usability of the system.The experimental results show that the prototype system can give the user real and continuous force feedback in the teaching process,and can also realize the deformation simulation of abrasive belt,which provide a flexible and effective programming solution for the grinding of complex parts.