| The automatic transmission technology of the vehicle has entered into intelligentized epoch, in which the development trend is to apply advanced technology into control system of the vehicle. As a kind of special vehicle, construction vehicle possesses very important status in vehicle family. The complexity of the operation, the badness of working conditions, the variety of working tasks and the frequent gear-shifting of the drivers result in high labor intension and low working efficiency in which it is difficult to maintain high driving efficiency. It is urgent to adopt robot technology to construction vehicle and develop intelligentized automatic transmission system to adapt specific working environment and improve vehicle performance. Realizing automatic transmission on construction vehicle has special and practical significance on breaking overseas products' monopoly to us and enhancing integrated economy strength of our country.This Ph.D. dissertation, taking ZL50 wheel loader as the research project, is thought to be a theoretic and experimental study to apply vehicle technology, electron technology, computer technology, artificial intelligent control technology and transducer technology to the automatic control for hydro-mechanical transmission of construction vehicle. Combining the project of National Foundation for Natural Sciences: Research on Automatic Transmission Technology for Construction Machinery (serial number: 50075033), it refers to the achievements the predecessors have attained and realizes to improve working performance of vehicle's transmission system and exert vehicle's driving output and fuel economy in the most extent. The powertrain system of modern construction vehicle usually consists of engine, hydrodynamic torque converter and gearbox while torque converter is an important component of the system which can not only lighten the impact from fluctuant load, improve vehicular performance at low-speed and overload but also realize automatic speed-adjusting within limited speed range. However, because of the intrinsic hydrodynamic losses of torque converter, the whole efficiency of transmission system falls down greatly which sets back its application. Aiming at the characteristics of hydro-mechanical transmission, CNN (Chaotic Neural Network) control technology is employed to design automatic gear-shifting strategy of construction vehicle based on the discussed optimal driving or fuel economy shift-decision. The intelligent control system on automatic transmission of construction vehicle is built up so that the controlled vehicle can adapt automatically to the working condition and the outer load by means of being endowed with intelligentized action. And furthermore, chaotic optimizing algorithm, which inherits neural network control technology's excellence, is introduced to improve the precision and respond speed of the control system so that it is possible that the system works with higher efficiency. Combined with dynamic simulation technology, simulation research on automatic transmission system of construction vehicle is carried through. Electronic control unit(ECU)of automatic transmission is developed with the design and debugging of the hardware and software of control system. Finally, a testing experiment on test-bench of transmission system is carried out to validate the availability of control algorithm and test the integrated performance of automatic transmission control system. Following is the introduction about every chapter of the dissertation.In chapter one, the development trends of oversea and inland vehicle's automatic transmission are introduced according to the phylogeny of automatic transmission technology and the application productions of the technology in construction machinery are emphasized. Referring to the current situation of our country, the important significance of adopting automatic transmission on construction vehicle is discussed. It has been made clear that AT technology is the necessity to the development of human civilization...
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