Research On The Synthesizing Control For Promoting The Intelligent Gearshift Performance Of The Construction Vehicles

Construction machinery and equipment industry has been the backbone of the Chinese machine building industry and played a important role in every area of the national economy such as in energy sources, water conservancy, communications and national defense in recent years. The rank of construction vehicles manufacturing industry of a country in the world reflects its level of technology and general strength. The study on the intelligent control of the construction vehicles will improve the control performance of the whole products as well as their power train systems. As a result, the high tech portion in the construction vehicle products will be increased, which will lead to a higher ratio of performance to price.The mobile vehicles with implementing devices for earth moving purpose are generally known as construction vehicles. Generally, all kinds of innovative measuring and controlling techniques are required to improve the performance of the power train system of the construction vehicles because of their rugged, complicated and variable working conditions , so that the machines are able to work with intelligent features and higher efficiency to ease the tiredness of the drivers largely. Not only the good performance in power but also in traction is required to ensure the construction vehicles giving out enough traction force without any loss of the efficiency of their engines, because there exists very large resist load to overcome while the machines are in operation, so as to promote the economic features of the machines and reduce their operation cost.The Intelligent gear-shifting technique of the construction vehicles is the core of the problems to be studied and solved urgently. The automatic gear-shifting technique of the construction vehicles is coming to an age of intelligentizing and the continuous progress of the control strategies is featuring the development of the automatic gearshift technology of the machines.The issues of the intelligent gear-shifting and its control strategies are far from being solved completely. The study on the intelligent gear-shifting of the construction vehicles is still in thestage of experimenting on the test rig in China; The intelligent gear-shifting technique in some developed countries has gone further than that in China and had some practical uses, but the intelligent control strategies has not been perfect and the machines with them have not been widely used at present.Through the synthesizing study on all aspects of the construction vehicle power train system with human simulating intelligent and fuzzy control strategies in this paper, the general performance of the intelligent gear-shifting has been promoted, i.e., the vehicle is enabled to shift intelligently according to the traveling speed and the load variation; in the mean time, the operation of the engine matches the working condition of the machine to ensure the highest working efficiency and to reach the goal for energy saving of the power train system, which will lay the foundation for the industrialization of the intelligent gear-shifting control units of the construction vehicles. The research on which this paper is based has been funded by the project of Natural Science Foundation of China(NSFC), "Research on the intelligent automatic gear-shifting techniques of the construction vehicles"(No. 50075033).In this thesis, the typical construction vehicle, the ZL50 wheel loader is taken as the study object and the dynamic model of its power train system is built up; the automatic gear-shifting strategy based on the human simulating intelligent fuzzy control theory is adopted for the gearshift system of the construction vehicles; The dynamic model of the gearshift system of the ZL50 wheel loader is built up and the simulation is carried out with the MATLAB/SIMULINK software; the feasibility in applying the human simulating intelligent fuzzy control technique to the automatic gearshift system has been validated through the experiments on the test rig and the analysis of the experimental results; aiming at the...