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The passive pre-chamber (PC) is valued for its jet ignition (JI) and is suitable for wide use in the field of gasoline direct injection (GDI) for small passenger cars, which can improve the performance of lean combustion. However, the intake, exhaust, and ignition combustion stability of the engine at low speed is a shortcoming that has not been overcome. Changing the structural design to increase the fluidity of the main chamber (MC) and pre-chamber (PC) may reduce jet ignition performance, affecting engine dynamics. This investigation is based on non-uniformly nozzles distributed passive pre-chamber, which is adjusted according to the working medium exchange between PC and MC. The advantages and disadvantages of the ignition mode of PC and SI in the target engine speed range are compared through optical experiments on a small single-cylinder GDI engine.

Reinforcement learning is a promising approach to solve the energy management for hybrid electric vehicles. In this paper, based on the DQN (Deep Q-Network) reinforcement learning algorithm which is widely used at present, double DQN, dueling DQN and learning from demonstration are integrated; states, actions, rewards and the experience pool based on the characteristics of series-parallel multi-speed hybrid powertrain are designed; the hybrid energy management strategy based on D4QN (Double Dueling Deep Q-Network with Demonstrations) algorithm is established. Based on the training results of D4QN algorithm, multi-parameter analysis under state and action space, HCU (Hybrid control unit) application and MIL (Model in-loop) test research are conducted.

Diesel engine starts stably under extreme conditions of high altitude and low ambient temperature, which is of great significance to national economic development, national defense force and user safety. However, there are few studies on cold start performance and transient emission of diesel engines with ambient temperature below 0°C and altitude above 2000m. A simulation test system for high altitude and low temperature cold start of diesel engine is established in this paper. The cold start-up of a high-pressure common rail turbocharged heavy diesel engine discharged from the fifth stage in China at altitudes of 0m, 3000m and 4000m at 10°C, 0°C, -10°C and -20°C is studied. The ignition mechanism of diesel engine at high altitude and low temperature is put forward. The combustion characteristics of diesel engine at variable altitude and ambient temperature were studied.