Research On Control Strategy Of Regenerative Braking Of Hydraulic In-wheel Motor Drive System For Heavy-duty Truck

With the development of the automotive industry, the commercial vehicles,especially the medium or heavy-duty truck which is used for transporting largetonnage of goods in outdoor conditions, has been played an important role in thecompetitive market. The characteristic of this kind of vehicles is the complex workingenvironments, such as the off-road conditions, or the mine road and the steepmountain road. The driving wheels of the vehicle are likely to slip as other wheels arenot working, which would worsen the stability and the passing ability of the vehicle.This paper propose a new driving system names as hydraulic in-wheel motordrive system, it is composed with a hydraulic accumulator and a hydraulic motorwhich is installed in-wheel, and could be installed in traditional vehicle withoutchanging the original structure. When the vehicle is working in complex conditionssuch as off-road condition, the non-driving wheels will be turned to driving wheels bythe system so that the vehicle could fully use the wheel adhesion force to enhance itspassing ability and power performance. When the vehicle is working in brakingcondition, the hydraulic in-wheel motor driving system can convert the kinetic energyof the vehicle into hydraulic energy by hydraulic pump/motor and stored theregenerative energy in the hydraulic accumulator, and the energy will be released todrive the wheels when the vehicle is starting to drive or to accelerate, so that it couldlower the load of engine and decrease the emissions, so the braking energy has beenreused.This paper relies on the National Natural Science Fund Project "research onhydraulic in-wheel motor auxiliary driving control system for commercial vehicles ",mainly researches on the regenerative braking system for the heavy-duty truck which has been installed with hydraulic in-wheel motor driving system, and the research canbe concluded as follows:1. With the compare and analysis of the regenerative braking system in China andother countries, it has been proved that the hydraulic in-wheel motor drive systemcould enhance the economy and power performance of the heavy-duty trucks.2. On the bases of the construction and working principles of the regenerativebraking system of hydraulic in-wheel motor drive system, this paper conclude theconstrain factors for regenerative braking system and how to increase the energyrecovery efficiency, so as to establish a solid theoretical foundation for control ofbraking strategy.3. With the compare and the reference of other existing regenerative brakingstrategy, on the basis of legal regulations and the request of vehicle stability,combined with the working principles of the regenerative braking system of hydraulicin-wheel motor drive system, this paper proposed a new control strategy for thissystem.4. According to the new control strategy, with the software of Matlab/Simulinkand AMESim, this paper established the dynamic model of vehicle, regenerativebraking system model and the control model of regenerative braking system to saveenergy.5. On the basis of the established simulation model, different working conditionshave been chosen to verify the control strategy for regenerative system whether itcould work properly. According to the results of the simulation, by contrast andanalysis of different parameters of the regenerative braking system of hydraulicin-wheel motor drive system, this paper provides a foundation for furtherimprovement and optimization.