Dynamic Interaction Simulation Of Hydraulic Excavator With Terrain For Driving Simulator

With the advancement of China’s modernization process, engineering machineryis widely used in various fields of engineering construction. Driving simulator as themain research tool on vehicle performance and human-machine-environmentclosed-loop system features, for its characteristics of economy, security, repeatabilityand not be restricted by time, site, climatic conditions, are widely used in theautomobile industry and transportation, construction, etc. Engineering machinerydriving simulator can not only provide for the engineering workers practical, safe,economical auxiliary training means to solve the problems of high fuel consumption,high pollution and high risk in field driving training using real vehicle, but also beused for product design " WYSIWYG " to shorten the design cycle and reduce thedevelopment costs. But at present, most of the construction machinery drivingsimulator in domestic and foreign lack the dynamic interaction of vehicle with terrain,which cause the sense of reality is very low and couldn’t provide drivers enoughimmersion, forming the situation that demonstration effect is greater than engineering.Topic from military cooperation project with XCMG " Dynamic simulation testsystem of hydraulic excavator ", based on real-time multi-body dynamics and virtualreality technology, overall framework of visual simulation engine is designed, andsuccessfully realize the simulation of dynamic behavior of excavator, human-machine interaction, dynamically cutting of the soil, soil flow, etc.. The contents ofthe dissertation mainly include:First of all, on the basis of geometric entity modeling in visual simulation engine,real-time multi-body dynamics simulation platform, Vortex, is adopted to simulatedynamic characteristics of excavator, which also has complex collision detectionfunction.Secondly, on the basis of realistic simulation of terrain, dynamic interactionsimulation with physics behavior of excavator with terrain is realized. Textures andmesh are added to Digital Elevation Data collected from a region, which realize3D visualization of static terrain. In order to show the earthmoving operations intuitively,dynamic terrain is established by using Real-time Optimal Adaptive Mesh algorithmand texture pixel integration technology based on GPU, which can dynamicallychange terrain geometry and non-geometry attribute. Fully considering the actualoperating conditions of excavator and soil mechanical, on the basis of FundamentalEarthmoving Equation put forward by Reece, through introducing the terrain slopeangle, lateral friction force and acceleration force, the soil dynamic cutting equation ismodified. Soil cutting resistance can be obtained during the interaction. Thethree-dimensional Discrete Element Method is adopted to simulate the soil particle inearthwork, and Particle System is also used to simulate the effect of dust fog, whichimproves the sense of reality. Meanwhile, in order to simulate the rut effect ofexcavator with dynamic terrain, the forces of road wheel are obtained, and accordingto pressure–sinkage theory proposed by Bekker, the sinkage of terrain below roadwheel is calculated real-timely.Finally, the system is imported into a certain hydraulic excavator drivingsimulator. Some dangerous operations and daily operations such as excavation,outward transport, pour soil and other typical working conditions are carried on invirtual environment.Vehicle simulation based on real-time multi-body dynamics in virtual simulationinstead of real vehicle field training, realizes the real-time simulation of dynamicbehavior of excavator, human-machine interaction, etc.. The system hascharacteristics of high fidelity, well real-time performance and strong immersive, andcan be not only used for auxiliary training, but also used in the engineeringapplication, providing intuitive measurement method of the force and assembly check,motion analysis of product.