Abstract: A motor speed controller for an antilock brake system motor driven brake pressure modulator controls the speed during the pressure ramping phase of an antilock brake pressure control cycle by commanding periods of dynamic braking of the motor while the motor current is being controlled to ramp the pressure.

Abstract: Selective compensation for reductions in fueling capacity normally associated with extreme fuel vaporization rates in the fuel delivery means of vehicle engines, by improved estimation of the conditions normally precedent to such extreme fuel vaporization rates.

Abstract: An unobtrusive vehicular adaptive speed control system controls vehicle traveling speed in response to sensed obstacles preceding the vehicle, to driver influenced control parameters, and to a desired travelling speed set by the vehicle driver.

Abstract: A vehicle antilock control system provides for selectively enabling the rear wheels of a vehicle to free-wheel and thereby attain vehicle velocity to provide an accurate measure of the vehicle speed during antilock controlled braking.

Abstract: A brake system for the rear wheels of a vehicle applies brake pressure to each rear wheel so as to establish the rear wheel speed at a predetermined relationship to the speed of the front wheel on the same side of the vehicle. The brake pressure applied to each of the front and rear wheels is limited by antilock controlled braking in response to a sensed incipient lockup condition of the wheel. When a front wheel first enters into an antilock controlled braking, in response to an incipient wheel lockup condition, the brake pressure to the rear wheel on the same side of the vehicle is rapidly increased to induce an incipient wheel lockup condition thereby inducing antilock controlled braking of the rear wheel.

Abstract: An internal combustion engine air-fuel ratio control method and apparatus wherein a most favorable parameter selected from the group consisting of air, fuel, and recirculated exhaust gas is adjusted in response to detected deviation of the air-fuel ratio away from the desired ratio. Supplemental control is provided by means of the remaining parameters in the event that the most favorable parameter runs out of authority.

Abstract: A power shutdown sequence provides for an orderly power shutdown for master and slave processors sharing a single power supply while at the same time allowing the master and slave processors to retain all the information learned regardless of failures. If the master senses a shutdown condition, it sends the slaves a power down signal confirming its intention to power down the system and commanding the slaves to initiate shutdown procedures, including the storing of variables to memory. In addition, the master also initiates shutdown procedures, and after a minimum time determined sufficient to allow the slave to complete their shutdown procedures, the master powers down the system. The slaves may also initiate their own powerdown procedures if a failure in the communications link with the master is sensed.

Abstract: The air/fuel ratio of the combustion mixture in the cylinders of an engine is sensed and the sensed air/fuel ratio is controlled to a predetermined scheduled air/fuel ratio by controlling the amount of exhaust gases recirculated. When the exhaust gas recirculated is substantially zero, the air/fuel ratio is thereafter closed loop adjusted to a predetermined scheduled minimum air/fuel ratio when the sensed air/fuel ratio is less than the minimum and when the sensed air/fuel ratio is greater than the minimum while the operator command is at a maximum to thereby provide precise fuel limiting at a predetermined fuel limit schedule.

Abstract: In an antilock braking system, when wheel parameters including slip represent an incipient wheel lockup condition normally calling for a release of brake pressure during a pressure apply mode of an antilock braking cycle and the duration of the pressure apply mode is less than a predetermined threshold representing an abnormal rapid cycling of the brake pressure, the wheel slip threshold representing an incipient wheel lockup condition is increased, the rate of increase in brake pressure during the brake pressure apply mode is set to a high level and the pressure apply mode is continued during which the wheel brake pressure is ramped at the increased rate. These steps are repeated while the wheel parameters represent an incipient wheel lockup condition normally calling for a release of brake pressure until the time of the pressure apply mode equals the predetermined threshold representing a normal brake pressure cycling period.

Abstract: The fuel control routine of an engine control module sets a cold enrichment schedule used for engine starting when the engine is cold. The enrichment value is dependent on coolant temperature. To prevent plug fouling in a new vehicle subject to short engine run times, the enrichment value is reduced if the mileage is below 50 miles, the coolant temperature is within set limits and the previous engine run time was shorter than a set period.

Abstract: When an incipient overtemperature condition of a catalytic converter of a vehicle is sensed, a cylinder of the vehicle engine having combustion conditions giving rise to the overtemperature condition is identified by selectively disabling fuel delivery to each of the cylinders of the engine in turn and monitoring the response of the converter temperature. If the disabling of the fuel to a particular cylinder results in recovery from the incipient overtemperature condition, fuel to that cylinder is maintained disabled to provide overtemperature protection of the converter.

Abstract: A vehicle parking brake system automatically adapts to the road surface condition when operated while the vehicle is moving. The parking brake pressure is automatically controlled, in response to an operator command to initiate the parking brake function or in response to a failure of the hydraulic front brakes while the vehicle is moving, to establish and limit wheel slip at a desired controlled slip between each of the braked wheels and the road surface so as to automatically adapt to the road surface coefficient of friction.

Abstract: An engine equipped with a low resolution crankshaft rotation encoder is diagnosed by measuring the average speeds for each encoder period, deriving estimated instantaneous speeds for top dead center (TDC) positions for each cylinder and for the points midway between TDCs. Speed changes calculated from the estimated speeds for the compression and combustion phases of each cylinder provide measures of the compression and power output of each cylinder. An engine speed signature trace derived from the estimated speeds is displayed to reveal speed changes and a composite display of several consecutive signatures provides further information.

Abstract: An on-line, non-destructive method and apparatus monitors a welding process and detects faulty welds by analyzing the average frequency of the airborne radiation emitted from a weld during the welding process. A sequence of measured average frequency values corresponding to sequential blocks of time during the weld are individually compared to a predetermined frequency threshold value. Overall weld integrity is discerned by comparing the number of average frequency values exceeding the threshold value to the number of average frequency values not exceeding the threshold value.

Abstract: An adaptive actuation verification method monitors the difference between a desired position and an actual position of a movable device, to ensure that the actual position of the device is approaching the desired position in an acceptable manner. A range of acceptable approaches is calculated based on the response capability of the movable device. The range is updated on-line to account for any changes in the response capability. An actuation fault is assumed when the device does not approach the desired position within the calculated range.

Abstract: A comprehensive air injection system diagnostic uses hardware already available on many vehicle exhaust systems to monitor the oxygen content of the exhaust, so as to indicate steady state oxygen levels therein that are not in accord with the present state of the air injection system, and accordingly are assumed to be the result of a failure in the air injection system.

Abstract: The current to the motor of a motor driven pressure modulator of an antilock brake system is controlled at a high value in response to a sensed incipient wheel lock condition so as to rapidly release the brake pressure for a calibrated time period that is a function of wheel parameters to reduce brake pressure by an amount determined to effect a recovery from the incipient wheel lock condition under normal antilock controlled braking. After the calibrated time period, the motor is braked so as to quickly halt its rotation and therefore the rapid pressure reduction by applying a motor brake current to the motor by controlling the motor current in the pressure apply direction. The duration of this rapid reduction of brake pressure and therefore the amount of pressure reduction is independent of a sensed recovery condition of the wheel and is based solely on an open loop calibration value determined to effect wheel recovery from the incipient wheel lock condition.

Abstract: A traction controller which modulates brake pressure to prevent excessive wheel spin in each of the driven wheels of a vehicle senses a side to side spin cycling condition of the driven wheels and increases the brake pressure of the driven wheel having the lesser of the two driven wheel brake pressures to a larger percentage of the other driven wheel brake pressure to inhibit the side to side spin cycling condition. The side to side spin cycling condition is represented by one driven wheel accelerating with a positive jerk value while the other driven wheel is decelerating with a negative jerk value.

Abstract: The period of an initial apply motor current in each apply phase of an antilock brake pressure cycle in a motor driven pressure modulator antilock braking system is adaptively controlled following a sensed recovery from an incipient wheel lockup condition to establish substantially a steady state condition relationship between current and pressure before motor current is ramped to ramp brake pressure. The period of the initial apply motor current is made a function of the amount of pressure decrease during a prior release phase portion of the antilock brake cycle to account for the greater increase in brake pressure to the initial reapply value.

Abstract: The fuel system of an internal combustion engine diagnosed based on a learn term adjusted in response to a closed loop adjustment of the air fuel ratio and which is used along with the closed loop adjustment to determine the fuel amount supplied to the engine. The learn term is adjusted at a first rate based on the integral correction term. If the learn term reaches a predetermined primary rich or lean limit value and the closed loop integral adjustment reaches its authority limit, the learn term is further adjusted at a second rate that is slower than the first rate. When the learn term exceeds a predetermined secondary rich or lean limit value representing an adjustment that is greater than the adjustment represented by the corresponding primary rich or lean limit value, a fuel system fault is indicated.