摘要:
An internal combustion engine fuel system applies injection control pressure to fuel injectors (26) to force fuel into combustion chambers (28). A processor of a control system (22) develops data values for injection control pressure set-point (ICPC—T13) representing desired injection control pressure and evaluates (134) the injection control pressure set-point data values for compliance with an allowable dynamic range defined by a data value for a minimum dynamic limit correlated with engine speed (N) from a function generator (132) and a data value for a maximum dynamic limit correlated with engine temperature (EOT) from a function generator (130). The processor limits the data value of desired injection control pressure that is subsequently processed to control injection control pressure applied by the fuel system to the fuel injectors to the allowable dynamic range.
摘要:
A schedule (164, 166) correlates data values of closed-loop gain (KP, KI) with engine temperature values (EOT) and engine speed values (N). A control strategy develops a data value (ICPC_DES) representing desired injector control pressure (ICP) set-point, processes ICPC_DES and a data value (ICP_MPA) representing actual ICP to develop ICP error data value (ICP_ERR) for closed-loop P-I control (160, 162) of actual ICP. Data values for closed-loop proportional and integral gains are obtained from the schedule based on measured engine temperature and measured engine speed. ICP become less subject to undesirable fluctuations that might otherwise change fuel injection quantity in ways detrimental to attainment of desired tailpipe emission objectives.
摘要:
This invention relates to a method for protecting an exhaust gas recirculation (EGR) valve from fouling due to hydrocarbon condensation at low EGR cooler outlet exhaust temperatures. In modern internal combustion engines exhaust gas recirculation (EGR) valves provide a means to recirculate exhaust gases into the intake air stream. The EGR valve regulates the flow of exhaust gas entering the stream. The EGR valve can experience fouling due to the condensation of hydrocarbons at low EGR cooler outlet exhaust temperatures. Typically, fouling occurs when the internal combustion engine is operating at relatively low temperatures, namely during low speed and/or low torque operations. The effects of fouling an EGR valve include higher emission levels, reduction in fuel economy, and rough idling.
摘要:
A motor vehicle engine (10) has a glow plug system (14) for aiding combustion of fuel in combustion chambers of the engine when the engine is cold and an ignition switch (16) is operated to crank the engine. A first circuit signals the cold start aid to commence operation of the cold start aid in anticipation of engine starting. A second circuit indicates a fault in the cold start aid. A third circuit, that includes a warning signal device (38), activates the warning signal device to inform a driver of the vehicle of the indicated fault upon the first circuit having signaled the cold start aid to commence operation and the second circuit having indicated a fault in the cold start aid.
摘要:
Desired engine fueling data FQL—MFD—TQL is processed by a derivative variable time function (40) embodied in an algorithm to develop a data value EGR—MFD—DER representing the time derivative of desired fueling. The algorithm comprises certain selectable parameters (EGR—DTS, EGR—MFD—KF, EGR—MFD—KD). An iteration of the algorithm includes processing FQL—MFD—TQL according to a first function (40A) to yield a first data value and according to a second function (40B) to yield a second data value. A third function (40C) subtracts the second data value from the first to yield a data value for the time derivative that forms one input to a map (42). A second input to the map is a data value for mass airflow (MAF—GMS). The map provides data for calculating the set point of an EGR valve (36). The invention provides improved control of EGR during fueling transients.
摘要:
A control system (58) for controlling the extent to which a valve (50) selectively by-passes exhaust flow around one of two turbines (18T, 20T) in an engine exhaust system (14). A desired set-point (TCBC_DES) and the actual set-point of operation of the valve are used to develop a set-point error for closed-loop control of the actual set-point. A data value for closed-loop gain is selected from a schedule (164, 166) based on engine speed and fueling. The selected data value of closed-loop gain and the set-point error data value are used to create a data value for a closed-loop output (TCBC_DTY_PIF) that is used to create a data value for a final output for forcing the actual set-point to the desired set-point.
摘要:
An engine control system (10, 12) and method for improving stability of engine running speed when torque subtractions (TTS) from gross torque change while the engine (14) is running at a constant speed, such as at low idle speed. Engine speed error data (Nerror) is processed according to one or more control functions (52, 54, 56) each having gain determined by the torque subtraction data value via function generators (58, 60, 62) to develop fueling adjustment data (P-FGT, I-FGT, D-FGT) for compensating desired engine fueling (MFDES) for the torque subtraction data (TTS).
摘要:
An EGR control method to prevent condensation within the EGR system uses a temperature sensor signal from an EGR cooler exhaust gas outlet to model or estimate exhaust manifold gas temperature upstream of the cooler. If the estimated exhaust manifold gas temperature falls below a predetermined level, the engine control system closes or partially closes the EGR control valve to stop EGR flow through the cooler and the EGR valve.
摘要:
A motor vehicle (10) has wheels (22F, 22R) on which it travels, a powertrain (12) for delivering propulsion torque to at least some of the wheels to propel the vehicle, and a service brake system (24) having service brakes (28). When the service brakes are applied by a service brake actuator (26), braking torque is applied to at least some of the wheels. A first device (36) provides data representing a velocity that correlates with velocity of the vehicle, and a second device (38) associated with the actuator provides data that distinguishes between application and non-application of the service brakes by the actuator. A processor (34) monitors data from the first and second devices and processes the monitored data (FIG. 2) to provide a data output BPP_FLT when the first device has disclosed velocity change indicative of the service brakes having been applied without the second device having disclosed that the service brakes have been applied.
摘要:
A first fuel value (FL_Signal) indicative of the quantity of fuel presently in a fuel tank (34) and a second fuel value (FL_LOW_THLD) representing a quantity of fuel in the tank at which a maximum Injection Control Pressure (ICP) limit should be changed are processed by a processor (22). When the result of the processing discloses that the second fuel value is less than the first fuel value, the maximum ICP limit is reduced from a greater value (ICPC_NORMAL_LMX) to a lesser value (ICPC_FL_LMX).