초록 ▼

An engine control system comprising: a mass air flow sensor in an air intake path for a vehicle engine and providing a first input signal indicative of mass air flow through the mass air flow sensor; an air pump unit having an inlet coupled between the mass air flow sensor and the vehicle engine and

An engine control system comprising: a mass air flow sensor in an air intake path for a vehicle engine and providing a first input signal indicative of mass air flow through the mass air flow sensor; an air pump unit having an inlet coupled between the mass air flow sensor and the vehicle engine and an outlet coupled in a path of exhaust from the vehicle engine, wherein the air pump unit is responsive to a first control command; a mass air flow estimator responsive to a set of measured engine parameters for providing a second input signal indicative of mass air flow into the intake manifold; and a control unit including a first control command generator responsive to the first and second input signals to provide the first control command responsive to a difference between the first and second input signals, wherein the difference between the first and second input signals represents an estimate of the instantaneous secondary air flow. If the system is mechanized to allow modulation of the secondary air system with a duty cycle, this further enables closed-loop control of secondary air provided by the air pump. The system effectively estimates instantaneous secondary air flow, enabling control of fuel and air to the engine in response to the estimated secondary air flow to provide tight control of exhaust chemistry and a strong exotherm to heat the catalytic converter. The system enables robust performance of the emission control system over an extended time as changes in pump airflow are directly estimated and appropriate control actions may be taken to give optimal system performance.

대표청구항 ▼

[ We claim:] [1.] An engine control system comprising:a mass air flow sensor (62) in an air intake path for a vehicle engine (44) and providing a first input signal indicative of mass air flow through the mass air flow sensor;an air pump unit (72) having an inlet (68) coupled between the mass air fl

[ We claim:] [1.] An engine control system comprising:a mass air flow sensor (62) in an air intake path for a vehicle engine (44) and providing a first input signal indicative of mass air flow through the mass air flow sensor;an air pump unit (72) having an inlet (68) coupled between the mass air flow sensor and the vehicle engine and an outlet (76) coupled in a path of exhaust from the vehicle engine, wherein the air pump unit is controllable to pump secondary air from the inlet to the outlet;a first estimator (154) responsive to a set of measured engine parameters for providing a second input signal indicative of mass air flow into the intake manifold (40); anda first actuator, responsive to a first control command, controlling at least one function of a set of functions comprising: (a) fuel into the vehicle engine and (b) secondary air provided to the outlet of the air pump unit; anda control unit (12) including a first control command generator (152, 162) providing the first control command responsive to a difference between the first and second input signals, wherein improved control of chemistry and equivalence ratio of gases entering a catalytic converter (90) is achieved.