| Bulldozer is one of the main equipments for construction machinery, and it plays an important role in the country’s infrastructure. Currently crawler bulldozer is driven by internal-combustion engine, and its transmission mode is mainly hydraulic mechanical transmission, this transmission mode has some disadvantages, such as low efficiency, high fuel consumption and high emission. This thesis mainly studies the hybrid crawler bulldozer. According to the various working conditions, the control strategies are proposed and simulated. The purpose of this thesis is to develop a new energy-efficient crawler bulldozer which can reduce emissions and improve fuel efficiency.Because of the special operating condition and working environment of the crawler bulldozer, the bulldozer has the possibility of applying the hybrid technology. Firstly, the power drive system of hybrid crawler bulldozer is selected, and the force of bulldozer is analyzed. Second, the control strategies are proposed under various working conditions, and the control flow charts are painted in detail. Finally, the vehicle dynamic mode based on Matlab/Simulink is established. The simulation project is as follows: different conditions of crawler bulldozer(straight, steering, in-situ center steering, half-shovel work) are simulated and it gets the basic dynamic characteristic curves. The dynamic performance of hybrid crawler bulldozer is analyzed under different working conditions. The influence of the super capacitor on the performance of the engine, the generator and the drive motor is analyzed under the vehicle control strategy. The simulation results show that under the action of super capacitor, the system can complete the energy recovery, and achieve the effect of energy conservation and emissions reduction. The rationality of the control strategy for the hybrid crawler bulldozer is verified, and it provides theoretical significance for the research of hybrid crawler bulldozer. |
PDF Full Text Request