Abstract: A method and system for determining and controlling air/fuel ratio during engine cold start operation relies on applying a monotonically decreasing fuel pulse width modulation to the engine and synchronously measuring the effect of the modulation on related engine event periods. This effect is utilized in estimating air/fuel ratio, which is then compared to the desired air/fuel ratio. The difference between the estimated air/fuel ratio and the desired air/fuel ratio is used in controlling the air/fuel ratio to the desired air/fuel ratio.

Abstract: A method for maintaining the rotational speed of a crankshaft of an internal combustion engine having a plurality of cylinders each having a spark plug wherein a predetermined amount of delivered fuel is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the camshaft or crankshaft includes the step of operating the internal combustion engine, measuring the rotational speed of the crankshaft, defining an expected engine speed, calculating a speed error as the rotational speed of the crankshaft less the expected engine speed, and changing the predetermined amount of delivered fuel to be combusted in each of the plurality of cylinders to reduce the speed error. The preferred embodiment is implemented in fuzzy logic.

Abstract: A catalyst system employed in the exhaust stream of an internal combustion engine (10) wherein the catalyst deterioration is monitored by an engine controller (26) connected to a first oxygen sensor (22) mounted upstream of a catalyst (18) and a second oxygen sensor (24) mounted downstream. After a cold start of the engine (10) a calibration of the first and second sensors is conducted, to assure accuracy between the two sensors and determine if one of the sensors has failed, and also a light-off time for the catalyst (18) is determined as one way to measure the deterioration of the catalyst.

Abstract: A security module is operatively disposed at the hardware/software interface within a printing apparatus. The module is disposed along a connection which acts as a medium for command signals to operate the printer hardware, and for status signals to indicate physical conditions within the hardware. The security module facilitates security procedures which control aspects of printer operation, particularly the creation of MICR characters.

Abstract: A system for the just-in time scheduling of camshaft timing for an internal combustion engine. A slave circuit generates an execution period corresponding to the execution period of the variable camshaft timing mechanisms. The control processor initiates the calculation of a correction signal base on the difference between the desired camshaft timing and the actual camshaft timing synchronous with the execution period of the variable camshaft timing mechanism. The calculation of the correction signal is executed by the central processing unit once and only once for each execution period of the variable camshaft timing mechanism.