Abstract: Variations in the speed of an internal combustion engine are measured and the distribution of the variations is analyzed for asymmetry, which indicates engine misfire. A threshold is generated as a function of engine speed increases and compared with engine speed decreases to detect asymmetry in the distribution.

Abstract: A chuck body has an internal cam unit eccentrically mounted within antifriction bearings, and the cam unit includes a workpiece gripper. A radial pin extends through the chuck body into a peripheral slot of the cam unit. When rotating in a first rotary direction, the chuck body and cam unit rotate in unison and a first workpiece diameter may be machined. When the rotation of the chuck body is reversed, inertial forces acting on the cam unit prevent immediate reversal of the cam unit rotation, and the pin moves through the peripheral slot, contacting the opposite end and driving the cam unit in reverse rotation; this relative motion between the chuck body and cam unit causes the workpiece to become offset, displacing the first workpiece axis from the chuck body axis of rotation. Consequently, as the reverse rotation is continued, a second workpiece diameter may be is machined about the chuck axis of rotation; the second diameter will be eccentric to the first diameter.

Abstract: Shunt results from drive line resonance of a vehicle's transmission superimposing cyclic oscillations onto the speed of the vehicle's engine. A feedback loop comprising at least one of a band pass filter having a high frequency cut-off characteristic greater than first order, a feedback loop in which the loop gain is a function of transmission ratio, and a non-linear transfer element arranged to have a gain whose magnitude increases with the magnitude of the input to the non-linear transfer element. Additionally shunt may also be controlled by a feed-forward controller based on an engine demand signal.

Abstract: Sensors measure the temperatures of exhaust gas upstream and downstream of a catalytic converter for internal combustion engine exhaust gas. The difference between the temperatures is multiplied by the rate of mass flow of exhaust gas and the result is integrated or low pass filtered to provide a measure of converter operation. Alternatively, the multiplication is omitted and the difference between the temperatures is integrated or filtered. Thus, the performance of the catalytic converter is monitored by evaulating the difference in the heat supplied to the catalytic converter and the heat removed from the catalytic converter by the exhaust gas.