A method of and apparatus for starting and accelerating a vehicle through a range of vehicle speeds during which the vehicle internal combustion engine is operated in a plurality of different operating modes is disclosed. The engine may first be cranked in a compressionless mode preparatory to starting and then run in a second mode at a relatively low speed for a warm-up interval as a six-stroke cycle engine where each engine cylinder cycle includes an essentially adiabatic compression and expansion. The system may then convert to a third mode of operation as a four-stroke cycle engine during normal engine operation. Different operating modes are available during this normal operation. Under high demand conditions, the engine may be run as a conventional inefficient but effective throttled engine or converted to operation in a fourth mode as a two-stroke cycle engine. The vehicle management system includes a first read only memory for storing a fixed table of engine operating parameters corresponding to various engine conditions, and a random access second storage means for storing a table of engine operating parameters corresponding to various engine conditions with the second table being initially the same as the first table. The system responds to sensed engine conditions to modify the parameters in the second table and controls the vehicle in accordance with the parameters stored in the second table. Both short term modification to accommodate dynamic changes in the sensed engine conditions and long term modification to compensate for relatively slow changes in the engine and the management system are made to the information in the random access memory. The modifications may be on an overall engine basis or an individual cylinder basis.

Vehicle management computer

Over the last two decades, advanced engine control systems have been developed that use cylinder pressure as the primary feedback variable. Production application has been limited by cost, reliability, and packaging difficulties associated with intrusive cylinder pressure sensors. Now, a low-cost cylinder-pressure-based engine control system has been developed that utilizes Pressure-Ratio Management (PRM) and non-intrusive cylinder pressure sensors mounted in the spark plug boss of four-valve-per-cylinder engines. The system adaptively optimizes individual-cylinder spark timing and air-fuel ratio, and overall exhaust gas recirculation (EGR) for best fuel economy and lowest emissions over the life of each vehicle. This paper presents the engine control and cylinder pressure sensor systems. Results are presented showing spark timing and EGR control, knock and misfire detection, cylinder-to-cylinder air/fuel balancing, and cold start control.

Cylinder-Pressure-Based Engine Control Using Pressure-Ratio-Management and Low-Cost Non-Intrusive Cylinder Pressure Sensors

A control system (140) for an internal combustion engine (100) having a plurality of cylinders (C1-Cn) and a rotatable crankshaft (110). Each cylinder (C1-Cn) has an electronically actuatable intake valve, exhaust valve (120, 125) and fuel injector (130). The control system includes a sensor (155) which monitors the rotation of the crankshaft (110) and responsively produces a crankshaft pulsetrain. A computer (216) produces operator parameter signals. The operator parameter signals including one of a plurality of operating modes of the engine (100). A first microprocessor (226) receives the crankshaft pulsetrain, responsively determines the speed of the engine (100) and produces a signal representative of the determined engine speed. A second microprocessor (222) receives the operator parameter signals and the engine speed signal, responsively determines valve and injection events for each cylinder (C1-Cn) to responsively achieve the one engine operating mode. The second microprocessor (222) produces signals representative of the determined valve and injection events.

Control system for an internal combustion engine

An approach to achieving uniform cylinder-to-cylinder air-fuel ratio control in the face of injector mismatch and unbalanced airflow due to engine geometry is presented. A key feature of the proposed method is that it functions well with the switching-type exhaust gas oxygen sensor commonly used in automobiles. The controller design, from modeling to experimental implementation in a dynamometer test facility, is documented. A method for achieving an extended operating region based on scheduling the sampling is described. >

Individual cylinder air-fuel ratio control with a single EGO sensor

A nonlinear port fuel injected automotive engine model is developed which can be used for the design of engine control algorithms, or within an algorithm for real time control. The model is being validated using a sequential fuel injection V-6 engine, and includes: ? intake manifold dynamics, ? fuel dynamics, and ? process delays inherent in the four stroke engine cycle. The model is compact enough to run in real time and can be used as an embedded model withim a control algorithm or an observer. Although developed for a specific engine, the model can be adapted to represent various types of automotive engines with a limited amount of engine data. Preliminary validation results look very promising.

Automotive Engine Modeling for Real Time Control Application

Controlling operation of an internal combustion engine at lean air fuel ratios uses an in-cylinder pressure sensor. The in-cylinder pressure sensor is coupled to each cylinder of the engine and measures in-cylinder pressure and generates an output signal as a function of such pressure. Airflow into the engine is also sensed and both the airflow and in-cylinder pressure are applied to the fuel controller for generating a fuel injection drive signal. Compensation means coupled to the in-cylinder pressure sensor means and airflow indication means modify the fuel air command applied to the engine as a function of airflow and in-cylinder pressure. The compensation means is also coupled to the fuel controller for applying a fuel command signal to the fuel controller thereby permitting engine operation at the lean air fuel ratio limit.

Adaptive lean limit air fuel control using combustion pressure sensor feedback

Advanced Real-Time Powertrain Systems Analysis

Real Time Engine Dynamic Analysis And Control

This paper contains a brief description of a mathematical model suitable for systematic cylinder pressure based analysis and control design. A linearized form and a simplified discrete form of the model are presented to illustrate the synthesis of a control system that resulted in cylinder-by-cylinder dilution limit control with coordinated optimal spark timing control. The control law was initially embedded into a rigorous dynamic-thermodynamic engine model characterization followed by implementation on an engine system and trimming of the control law gains in an experimental environment. Comparative modeling and simulation results are presented.

Gottfried Hogh

Papers

Adaptive lean limit air fuel control using combustion pressure sensor feedback

Advanced Real-Time Powertrain Systems Analysis

Real Time Engine Dynamic Analysis And Control

Cylinder Pressure Feedback Control Analysis Model