Development Of Pure Electric Loader Vehicle Controller And Its Functional Realization

In the face of increasingly serious environmental pollution and energy shortage,China has actively launched the "dual carbon" goal.As a large infrastructure country,China has a large amount of construction machinery,and with the continuous increase of infrastructure,the ownership of construction machinery is also increasing.Wheel loaders driven by traditional diesel engines have the disadvantages of large energy loss and serious Exhaust gas leakage.Therefore,it is of great significance to carry out electrification research for wheel loaders to achieve the "double carbon" goal in the field of construction machinery as soon as possible.As one of the cores of pure electric vehicles,the performance of the vehicle control unit(VCU)directly affect both security and reliability.Therefore,this paper develops and implements the VCU of the pure electric drive wheel loader prototype developed by the horizontal project of the research group.The main content includes the following 4 parts.(1)Based on the prototype of the pure electric drive loader jointly developed by the research office and the company,a vehicle model including a driver model,a battery model,and a vehicle longitudinal dynamics model was builed.A human-vehicle-road closed-loop simulation system was built in the MATLAB/Simulink environment.Under the "V" working condition,the model is simulated and verified,and the accuracy of the built model is confirmed by comparing with the Real job data.(2)To further achieve the energy-saving and efficiency advantages of pure electric drive loader,on the basis of analyzing its operating characteristics,a PSO-BP neural network algorithm is established to identify its working conditions,which is greatly improved compared with the identification accuracy of BP neural network.Next,the design of the drive control strategy at this stage is optimized,and the experiments show that the transition economy and operation efficiency of the loader are significantly improved.(3)Based on the requirements of pure electric loaders,the basic functions of VCU are analyzed.After that,the hardware and software of the VCU are developed.Hardware aspects include: main control chip selection,hardware minimum system circuit design,digital acquisition module circuit design,analog acquisition module circuit design,high and low side power drive circuit design and CAN communication circuit design.The software aspect includes: based on Simulink,the chip underlying driver interface module library has been developed.Based on the S32 DS integrated development environment,the underlying program design is completed,and the vehicle high and low voltage power control strategy,drive motor control strategy,bodywork motor control strategy,gear switching strategy,vehicle status parameters and fault monitoring strategy are built.(4)The developed VCU is tested,including hardware function test and real vehicle control strategy test.Firstly,the hardware functions of each module of VCU are tested,including power module function test,digital and analog acquisition hardware function test,high and low side power drive hardware function test,and CAN communication hardware function test.After that,the controller will be tested in real vehicles,and the high and low voltage power up and down functions,the driving information collection function of the whole vehicle,the gear switching function of the whole vehicle,and the CAN communication network function of the whole vehicle will be tested respectively.After the test is completed,the actual vehicle operation is performed to further proved the reliability of the VCU function.The test results show that the optimized efficiency of the whole vehicle shoveling operation is increased by 10%,and the economy during the transition is increased by 16.1%.The VCU developed has been tested to perform reliably and meet the functional requirements of pure electric loaders.