Research On Design And Control Strategy Of The Horticultural Electric Tractor Driving System

Modern agriculture is become demanding clean-energy and sustainable development increasingly in nowadays.Because of that in the agricultural machinery field,electric tractor is becoming a new research object hotpot.However,in China,still lack system method to design electric tractor's drive system;also lack index to judgement electric tractor's power performance,energy consumption.Therefore,this paper take the horticulture electric tractor as the research object,design its driving system,propose a dual-motor coupling driving structure;optimize the key layout parameters of the tractor;according to the operating conditions of the horticulture tractor to design drive control strategy.The specific content of this article are as follows:(1)Parameter design of the electric tractor chassis: Design the horticultural electric tractor electric chassis for gardening operations as the design object,and a coupled gearbox is designed with the dual-motor drive structure.Study the main working mode of horticultural tractors,and put forward the evaluation index of power and economy applicable to electric tractors.Finally,matching design the parameter of drive system main component,especially the key parameters such as motor power and battery capacity,gear transmission ratio and so on.(2)Dynamic model and optimized design of the drive system: Analyze the kinetics of tractor in plowing conditions,establish mathematical model of tractor dynamics,and use Simulink software to simulate the dynamic performance.Then,combined with the four-wheel drive tractor's structure,focus study to axle load distribution's influence on the driving efficiency,and propose optimal design method based on the motion efficiency and the slipping efficiency as the dual objective.At the same time,set up such as ground adhesion constraints,front and rear wheel rotation speed constraints,and transmission relationship constraints.The optimization model use the NSGA-? algorithm to calculate the multi-objective problem.The results show that the optimized tractor parameters are achieved the optimal balance between the motion efficiency and slip efficiency.(3)Tractor constant speed cruise control strategy: According to tractor drive control method,proposed a constant speed cruise control strategy.Analyzed the cause of resistance change during ploughing,design adaptive fuzzy PID algorithm to control tractor speed.The simulation results show that the controller can control the tracotr speed in the ideal interval,and when the soil resistance has mutation changes,the fuzzy PID control algorithm improved the recognition accuracy of the target tractor speed under different traction resistance.