Research On Energy Saving Control Techniques Of Wheel Loader Engine

According to the investigate on a certain type of loader domestic, such problem is encountered that the fuel economy is worse than the counterpart abroad, working condition recognition is ignored under controlling of the engine and transient energy saving control is disregarded. Aimed at the problems above, the energy saving control technology of the engine is studied systematically focusing on the control strategy based on working condition recognition in this paper, which is sponsored by the National Science and Technology Support Project “Research on Energy Saving and Emission Reduction Generic Technology of Engineering Machinery”(No. 2015BAF07B01).The main content is following:The architecture of energy saving control of loader engine is studied to weaken the difficulty of system design and sharpen system sensitivity to handle with the excessive difficulty of overall control system. The control objects are hierarchical in accordance with their priorities, which included security layer, working modes control layer and rotational speed control layer. The key points, difficulty and overall solution of the control system are analyzed and key techniques to realize the function is projected. Thus, the structure of study in this article is more clear, the design difficulty of control system is weakened, and instantaneity of control system is improved.Aiming at the controllability and high transient fuel consumption of engine, the dynamic response characteristic and transient fuel consumption test is conducted based on VCU Link controller. The test results show: VCU Link controller is controllable to the engine; dynamic property of the engine reaches the best when the angular acceleration is 1000 rpm/s and fuel economy of the engine reaches the best when the angular acceleration is 700 rpm/s with load.Aiming at the poor fuel economy of prototype, this article carries out energy saving control strategy of engine, based on working condition recognition. Several aspects are taken into consideration. Aiming at the failure of better energy saving owning to the monotonous working mode of prototype engine, working mode control strategy is designed based on the finite-state machine Stateflow, thus the switchover of various working modes is realized. Aiming at the integrality of vehicle control unit, control strategy of limping and security is designed. Aiming at the high transient fuel consumption of engine, transient energy saving control strategy is designed, which makes the loader reach a better dynamic property under the dynamic mode and a better fuel economy under the economy mode. Aiming at the multitasking and complicated operating conditions of prototype, multi-operation mode control strategy is designed to meet the challenges. Aiming at the fuel waste of idling, despinning energy saving control strategy is designed to reduce fuel consumption.Aimed at the precision of off-line simulation, Hardware-in-the-Loop simulation experiment and field test are conducted. Hardware-in-the-Loop simulation experiment result shows that control strategy of this article operates in accordance with expected. Field test result shows that dynamic mode of the strategy has a better dynamic property, which is appropriate for high speed and hard material shoveling and loading and economy mode of the strategy has a better fuel economy, which is appropriate for low speed and bulk material shoveling and loading.