Abstract: During operation of a single-cylinder test engine, a computer or other processor runs a simulation of additional “virtual cylinders” operating alongside the single cylinder as if all cylinders, real and virtual, were present in a real multi-cylinder engine. Temperature data from the virtual cylinders is generated, and the real cylinder is jacketed with flow passages which are supplied with heat transfer fluid at temperatures such that the thermal presence of the virtual cylinders adjacent the real cylinder is simulated. As a result of this thermal simulation, the real cylinder is able to more accurately simulate the performance that it would have if it was indeed present in a multi-cylinder engine.

Abstract: During operation of a single-cylinder test engine, a computer or other processor runs a simulation of additional “virtual cylinders” operating alongside the single cylinder as if all cylinders, real and virtual, were present in a real multi-cylinder engine. Temperature data from the virtual cylinders is generated, and the real cylinder is jacketed with flow passages which are supplied with heat transfer fluid at temperatures such that the thermal presence of the virtual cylinders adjacent the real cylinder is simulated. As a result of this thermal simulation, the real cylinder is able to more accurately simulate the performance that it would have if it was indeed present in a multi-cylinder engine.

Abstract: A control system for an internal combustion engine includes a virtual engine model which mathematically represents the states of the engine in real time, but which is programmed to provide the engine's states at least a fraction of an engine cycle (and preferably at least one-fourth of an engine cycle, i.e., one stroke) to several engine cycles in advance of the real engine. The mass flow entering and leaving the cylinder is modeled, allowing parameters such as the mass of air per cylinder (MAC) and residual exhaust gas to be computed, and thereafter used to generate engine control commands related to fuel injection (air/fuel ratio), spark advance, and so forth.

Abstract: A testing device allows a test engine (such as a single-cylinder test engine) to experience the air exchange characteristics of a multi-cylinder test engine having a greater number of cylinders. The test engine receives air from an air source (such as the atmosphere) through the interior passage of an air intake adapter, wherein valves on the passage walls separate the interior passage from a negative or positive pressure source. A processor (such as a computer) may actuate the valves to allow air to be pulled from the passage to simulate the effect of air intake into additional virtual cylinders (i.e., cylinders that would operate in tandem with the cylinder(s) of the test engine if the test engine had a greater number of cylinders), and/or to simulate the effect of forced air induction (i.e., turbocharging or supercharging).

Abstract: A dynamometer is coupled to a single cylinder version of a multi-cylinder engine. The dynamometer control system calculates the instantaneous dynamic torques (e.g., inertial, combustion, and/or other torques) that would normally be generated in the multi-cylinder engine. The control system then inputs the torque from the missing cylinders of the engine to the dynamometer, preferably by a hydraulic system capable of accurately applying these torque pulses. By inputting energy to the engine as well as receiving it, the single-cylinder engine can replicate the rapid transients that are experienced in multi-cylinder engine operation, and can therefore be made to have an instantaneous speed profile matching that of the multi-cylinder engine.

Abstract: A dynamometer is coupled to a single cylinder version of a multi-cylinder engine. The dynamometer control system calculates the instantaneous dynamic torques (e.g., inertial, combustion, and/or other torques) that would normally be generated in the multi-cylinder engine. The control system then inputs the torque from the missing cylinders of the engine to the dynamometer, preferably by a hydraulic system capable of accurately applying these torque pulses. By inputting energy to the engine as well as receiving it, the single-cylinder engine can replicate the rapid transients that are experienced in multi-cylinder engine operation, and can therefore be made to have an instantaneous speed profile matching that of the multi-cylinder engine.

Abstract: Disclosed is a method and apparatus for generating a synthetic measure of combustion quality which is particularly useful in diagnosing and controlling combustion quality in internal combustion engines. The synthetic measures, which may be generated utilizing an engine's actual speed or acceleration as an input, have the important qualities that they (1) accurately reflect the engine's actual combustion work at all nominal engine speeds, and (2) retain essentially the same characteristics (e.g., waveform shape) at all nominal engine speeds. These qualities significantly simplify combustion diagnosis and control. The synthetic measures for the overall engine may be resolved into the contributions from each individual cylinder in the engine if diagnosis and control of combustion quality in the individual cylinders is desired.