Simulation Optimization And Software Development Of Power Transmission System For Articulated Tracked Vehicle

Articulated tracked vehicles are two-section tracked vehicles that can be driven on various rough terrains and special roads such as the Gobi,forests,snowfields,and shallows.Not constrained by road conditions,these vehicles have an incomparable passing ability and thus they are widely used.But compared with the developed countries in the West,China has spent less time in developing those vehicles,and the gap between our country and them is large.Therefore,in order to enhance the market competitiveness of domestic articulated tracked vehicles,the matching analysis of their drivetrain is crucial to the improvement of the performance.Firstly,this thesis introduces the drivetrain of articulated tracked vehicles with internal combustion and hydraulic drive.Then it analyzes the working characteristics of the engine and the hydraulic torque converter,and respectively establishes mathematical models of the engine's external characteristics,the engine's universal characteristics and the hydraulic torque converter's primary characteristics.On this basis,this thesis introduces the working characteristics of the important components of other transmission systems,such as gearboxes,transfer cases,etc.Secondly,this paper introduces the matching calculation process of engine and hydraulic torque converter,and selects appropriate evaluation parameters to make a reasonable evaluation of the matching results.Then the present thesis illustrates the evaluation indexes of articulated crawlers' dynamic performance and fuel economy,followed by a summary of their calculation methods and procedures.Then,this study choose the internal penalty function method to solve the optimization model.It takes as the objective functions the acceleration time from a standing start,and the fuel consumption during that period.Meanwhile,constraint conditions are the basic dynamic requirements of the full vehicle,speed ratio requirements of the transmission,boundaries of each shift's transmission ratios and the boundary of the drive axle's transmission ratio.According to specific needs,certain weighting factors of dynamic performance and fuel economy are choosing for a corresponding optimal objective function in order to optimize the drive train parameters.Finally,based on the above theoretical research,adopting MATLAB as the development tool,this study writes a software of dynamic matching and drive train parameter optimization specially for articulated tracked vehicles.This software can not only calculate the dynamic matching and optimize the drive train parameter,but also save graphics and output data.In addition,this study also makes a certain type of domestic articulated tracked vehicles as an example,and carries out its dynamic matching calculation and optimal design of drive train parameters.These research results are comparing with those of enterprise test,and it verifies the rationality of the software we wrote.