Abstract: The present disclosure provides a method for controlling EGR rate of a low pressure EGR system, a system and a vehicle. The method calculates a molar concentration of water molecules of exhaust gas processed by EGR cooler, calculates a molar concentration of water molecules, obtains coefficient as to excess air, and calculates a molar volume ratio of air according to the coefficient. Under a maximum limit of humidity, an allowable EGR rate of the exhaust gas processed by the EGR cooler is determined and an allowable EGR rate of the mixed gas before entry into supercharger and/or compressor is also determined, a lower EGR rate between the two allowable rates is set as a maximum for application actual working conditions. The present disclosure solves a problem of condensation caused by an introduction of exhaust gas from the existing gasoline engine.

Abstract: The present disclosure relates to a thermostat fault diagnosis method. The method includes: a current environment temperature and a boundary temperature and initial opening temperature corresponding to the current environment temperature are acquired; engine thermal equilibrium state data determined based on coolant temperature change data in an engine are acquired; a current coolant temperature is acquired; and according to the engine thermal equilibrium state data and a relationship between the current coolant temperature and the boundary temperature and initial opening temperature, it is judged whether a thermostat is faulty.

Abstract: The present disclosure relates to a thermostat fault diagnosis method. The method includes: a current environment temperature and a boundary temperature and initial opening temperature corresponding to the current environment temperature are acquired; engine thermal equilibrium state data determined based on coolant temperature change data in an engine are acquired; a current coolant temperature is acquired; and according to the engine thermal equilibrium state data and a relationship between the current coolant temperature and the boundary temperature and initial opening temperature, it is judged whether a thermostat is faulty.

Abstract: An automotive generator control method includes inputting a current vehicle speed, an actual battery level, an actual battery temperature and an engine operating efficiency (S11); calculating an optimal battery level by using a preset first mapping table, on a basis of the actual battery temperature and the current vehicle speed; taking a difference between the actual battery level and the optimal battery level as a target power-generation difference (S12); calculating a target power-generation voltage by using a preset second mapping table, on a basis of the target power-generation difference and the engine operating efficiency (S13); and outputting the target power-generation voltage (S14). The automotive generator control method and control device can precisely control a power-generation voltage of a generator according to a current engine/vehicle working condition and a battery working condition, so as to achieve primary energy recovery of the generator in a highly efficient manner.

Abstract: An automotive generator control method includes inputting a current vehicle speed, an actual battery level, an actual battery temperature and an engine operating efficiency (S11); calculating an optimal battery level by using a preset first mapping table, on a basis of the actual battery temperature and the current vehicle speed; taking a difference between the actual battery level and the optimal battery level as a target power-generation difference (S12); calculating a target power-generation voltage by using a preset second mapping table, on a basis of the target power-generation difference and the engine operating efficiency (S13); and outputting the target power-generation voltage (S14). The automotive generator control method and control device can precisely control a power-generation voltage of a generator according to a current engine/vehicle working condition and a battery working condition, so as to achieve primary energy recovery of the generator in a highly efficient manner.