Design And Development Of Virtual Hydraulic Experiment System Based On Virtual Reality

Virtual Reality technology is widely used in medicine,industrial manufacturing,aerospace,education and other fields because of its high immersion,strong interaction and multi perception.Since 2020,in order to cope with the impact of COVID-19 on the traditional classroom,online teaching has been carried out all over the country.However,due to the influence of experimental sites and equipment,experimental courses can not be taught normally.Therefore,how to combine Virtual Reality technology with experimental teaching has become an urgent problem in the field of simulation teaching.Hydraulic experimental teaching is an important part of mechanical engineering teaching,and traditional hydraulic experimental courses are not only limited by the limited types and quantities of experimental equipment caused by cost issues,but also easily limited by time and space.Therefore,this thesis takes HTC Vive as an interactive tool,and takes hydraulic component disassembly experiment and hydraulic circuit experiment as research objects,based on the idea of "divide and rule",the key technologies such as assembly sequence planning of hydraulic components,hierarchical bounding box algorithm and 3D pipeline drawing algorithm are studied,developed a virtual hydraulic experimental system.The main study are as follows:(1)A virtual hydraulic component disassembly experiment scheme based on hierarchical cutset algorithm is proposed.In view of the irreversibility of hydraulic component assembly and the demand for the feasibility of assembly sequence for virtual disassembly and assembly.The hierarchical cut set method is used to solve the feasible assembly sequence,and the evaluation model of assembly sequence is established to determine the optimal disassembly sequence,which provides the basis for the disassembly experiment of virtual hydraulic components.(2)A collision detection algorithm between AABB level bounding box and mesh bounding box is designed for virtual hydraulic experiment.In the virtual hydraulic experiment scene,the establishment and update steps of AABB hierarchical bounding box are described,the contact test method between elements is designed,and the contact point coordinates of hydraulic components are output.It is found that the algorithm can effectively improve the collision detection accuracy of hydraulic components assembly.(3)The three-dimensional pipeline drawing algorithm based on NURBS curve and the oil flow model based on particle system are proposed.Aiming at the real-time connection problem of three-dimensional pipeline,the algorithm of three-dimensional pipeline based on NURBS curve is established by combining NURBS curve with mesh modeling method;Aiming at the problem of displaying the working principle of hydraulic components,the particle generation process is analyzed,and the particle attribute parameters and flow area are set.Taking the inclined axis axial piston pump as an example,the MGS Mechniery is used to simulate the motion law between the motion pairs,so as to provide a new method for the dynamic demonstration of the working principle of hydraulic components.(4)The virtual hydraulic experiment prototype system based on VR is developed.Based on the research of key technology and function design of the system,HTC Vive virtual reality handle and helmet reality are used as interactive tools.A virtual hydraulic experiment prototype system based on VR is developed,which is designed from three modules: hydraulic component disassembly experiment,hydraulic circuit experiment and teaching evaluation,which provides an effective auxiliary means for hydraulic experiment teaching.