Optimization And Simulation Control Of Six-swing-arm Wheel-legged Chassis For Forestry

Chassis is the key component of forestry equipment,which directly determines whether forestry equipment can go up into the forest.Steering performance and passing ability are two important criteria for measuring the power chassis of forestry.In view of the shortcomings of the six-swing-arm wheel-legged chassis for forestry,this paper presents an optimal design scheme for it,which can improve its steering performance and enhance its passing ability and obstacle-surmounting ability.The main research contents and methods are as follows:1.Based on the comprehensive analysis of the structural characteristics and functional requirements of construction machinery and wheel-leg chassis at home and abroad,the key components of the six-swing-arm wheel-legged chassis for forestry were theoretically analyzed,a mechanical structure for four-wheel steering and full-wheel driving was proposed and components were redesigned and optimized by applying mechanical design,higher mechanism theory and robotics theory.2.The kinematics model of the six-swing-arm wheel-legged chassis for forestry was established by D-H method.The theoretical relationship between the position and attitude angle of each wheel-leg and the height of obstacle-surmounting was obtained by analyzing the range of the position and attitude angle of each wheel-leg,and then the optimal installation position of the electro-hydraulic push rod was obtained.The co-simulation analysis of the electro-hydraulic push rod was carried out by using ADAMS/Simulink.The results show that the stability and obstacle-surmounting ability of the chassis are improved.3.The differential steering mathematical model of the chassis is established by using Achermann-Jeantand steering model,and the relationship between deflection angle and speed of six wheels in the differential steering process is obtained.The control model is constructed by MABLAB/Simulink.On the basis of the model,the ADAMS/Simulink co-simulation of circular trajectory is carried out.The results show that the Achermann-Jeantand steering model fully meets the steering differential requirement of the chassis,and the circular trajectory deviation is 4 mm,which meets the steering design requirement of the forestry chassis.In this paper,the six-swing-arm wheel-legged chassis for forestry is optimized.The optimized chassis can work in full accordance with the design requirements.Its minimum steering radius can reach 1500 mm,and the maximum obstacle-crossing height can reach 440 mm.The correctness of theoretical analysis of chassis steering performance and obstacle surmounting performance is verified by ADAMS/Simulink co-simulation.Its steering ability and obstacle-surmounting ability fully meet the requirements of forestry equipment chassis in Chinese forestry production,which provides basic guarantee for the mechanization,automation and intelligent development of forestry equipment in China,and lays a theoretical and technical foundation for the research of special forestry equipment chassis.