| As the world energy crisis increasingly serious, fuel prices is soaring, which brings huge impact to economic development. In addition, because of inefficient use of fossil fuel, world environment pollution is becoming more and more serious. Designing the low energy consumption, high energy utilization ratio and low emission machinery became a hot topic for research workers. In the thesis, an Underground Loader is set as the research object. According to its adopt traditional hydraulic friction braking mode, a lot of kinetic energy are wasted in braking, and the brake piece is friction loss, so, an braking energy recovery scheme is introduced, and some theory analysis research about the application of braking energy recovery system are carried out in the paper. The mainly job are as the following:1. According to the braking characteristics of underground scrapers, a suitable energy storage of braking energy recovery scheme for underground Loader is chose. Namely, using variable pump transform the kinetic energy of underground loader into hydraulic energy and storing it in accumulator. The paper analyses the largest recycling energy and specific matching parameters of each hydraulic subsystem of 2 m3 underground loader, determine recycling braking energy use steering system and braking system, which can be make full use of recycling braking energy.2. The paper establish the mathematical model of braking energy recovery scheme by adopting transfer function method, and simulation study the braking energy recovery system in MATLAB/Simulink software, which lay a foundation for the optimization of three key parameters;3. Simulation study of the three key parameters(accumulator volume, change pressure and hydraulic pump discharge)which Influence braking performance and energy recovery are carried out, and the influence law to energy recovery rate is revealed. On this basis, taking obtaining the biggest energy recovery rate as the goal, and on the conditions of satisfying the steering system pressure and oil volume, combining with brake minus acceleration requirements of Man-Machine Engineering, the three key parameters is optimized by adopting genetic algorithm. 4. Braking stability of the Underground Loader which use braking energy recovery system is analysis studied. Moreover, using fuzzy control method to control the braking force which supplied by energy recovery scheme, which make brake deceleration output keep steadiness. In addition, A fuzzy controller is designed by using fuzzy toolbox of MATLAB software, and the simulation study is carried out in MATLAB software.5. Braking energy recovery experiment platform is constructed and the influence law of accumulator volume and charge pressure to energy recovery rate is studied by experiment. Moreover, the analyses of the two parameters in paper is verified by experiment. |
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