Delco Electronics Corporation

Other

William D Wise

Dale J Kumke

Matthew D Sale

Everett R Lumpkin

Brian W Schousek

Terry L Fruehling

Marc L De Wever

Larry R Hach

Clifford L Carpenter

A system for anti-lock brake and traction control has a control circuit comprising a microprocessor on a silicon die. Inputs from several variable reluctance wheel speed sensors are multiplexed to a single channel on the same die for signal processing including diagnostics, A/D conversion, square wave generation for each sensor by a state machine, end wheel speed determination from the square waves. The state machine algorithm tracks signal peaks and valleys and uses a dual hysteresis method of generating output transitions to capture all cycles of a signal having single cycle anomalies while rejecting noise. A single rear wheel sensor having twice the frequency of front wheel sensors for equal wheel speeds is processed twice as often as each front sensor. The diagnostics include detecting sensor and harness short and open circuits by comparison of signals to programmable thresholds and fault timing and latching by gauging open and short signals against programmable time limits. Common mode noise rejection is accomplished by detecting common mode aberration and disabling an A/D converter during the aberrations. Other diagnostics include inputting known artificial signals at sensor inputs or wheel speed circuit inputs and checking for expected outputs, or by calculating wheel speed in parallel paths having the same square wave inputs and using different algorithms.

Dual hysteresis method of generating square waves from automotive wheel

A system for anti-lock brake and traction control has a control circuit comprising a microprocessor on a silicon die. Inputs from several variable reluctance wheel speed sensors are multiplexed to a single channel on the same die for signal processing including diagnostics, A/D conversion, square wave generation for each sensor by a state machine, and wheel speed determination from the square waves. The state machine algorithm tracks signal peaks and valleys and uses a dual hysteresis method of generating output transitions to capture all cycles of a signal having single cycle anomalies while rejecting noise. A single rear wheel sensor having twice the frequency of front wheel sensors for equal wheel speeds is processed twice as often as each front sensor. The diagnostics include detecting sensor and harness short and open circuits by comparison of signals to programmable thresholds and fault timing and latching by gauging open and short signals against programmable time limits. Common mode noise rejection is accomplished by detecting common mode aberration and disabling an A/D converter during the aberrations. Other diagnostics include inputting known artificial signals at sensor inputs or wheel speed circuit inputs and checking for expected outputs, or by calculating wheel speed in parallel paths having the same square wave inputs and using different algorithms.

Dual hysteresis method of generating square waves from non-uniform

A system for anti-lock brake and traction control has a controller circuit comprising a microprocessor on a silicon die. Inputs from several variable reluctance wheel speed sensors are multiplexed to a single channel on the same die for signal processing including diagnostics, A/D conversion, square wave generation for each sensor by a state machine, and wheel speed determination from the square waves. The diagnostics include detecting sensor and harness short and open circuits by comparison of signals to programmable thresholds and fault timing and latching by gauging open and short signals against programmable time limits. Common mode noise rejection is accomplished by detecting common mode aberration and disabling an A/D converter during the aberrations. Other diagnostics include inputting known artificial signals at sensor inputs or wheel speed circuit inputs and checking for expected outputs, or by calculating wheel speed in parallel paths having the same square wave inputs and using different algorithms.

Method and apparatus for anti-lock brake single channel wheel speed

A system for anti-lock brake and traction control has a control circuit comprising a microprocessor on a silicon die. Inputs from several variable reluctance wheel speed sensors are multiplexed to a single channel on the same die for signal processing including diagnostics, A/D conversion, square wave generation for each sensor by a state machine, and wheel speed determination from the square waves. The diagnostics include detecting sensor and harness short and open circuits by comparison of signals to programmable thresholds and fault timing and latching by gauging open and short signals against programmable time limits. Common mode noise rejection is accomplished by detecting common mode aberration and disabling an A/D converter during the aberrations. Other diagnostics include inputting known artificial signals at sensor inputs or wheel speed circuit inputs and checking for expected outputs, or by calculating wheel speed in parallel paths having the same square wave inputs and using different algorithms. Sensor and harness resistance is checked by retrieving differential voltages measured when the wheels are stationary, each voltage being a function of the sensor and harness resistance.

Method of measuring wheel speed sensor impedance

Faulty operation of a two-lead wheel speed sensor in a vehicle control system is detected and distinguished from transients by measuring a common mode voltage of the sensor and applying such voltage to a window comparator. Analog-to-digital conversion circuitry for capturing wheel speed signals is disabled so long as the measured voltage falls outside the comparator window. When the measured voltage is outside the comparator window for at least a given time limit, an open circuit fault condition is indicated. Additionally, the sensor lead voltages are compared to threshold voltages; when both voltages exceed the thresholds for at least a given time limit, a short circuit fault condition is indicated. The windows, thresholds and time limits are programmable by the vehicle control system computer.

Method and apparatus for detecting faulty operation of a wheel speed

A vehicle controller in which inputs from several wheel speed sensors are used to compute wheel speed. A redundant circuit in the controller receives the sensor input signals and computes wheel speed in a different, software intensive, way. The primary and redundantly computed wheel speeds are compared to validate the primary controller circuitry and the portion of the controller used to process compute the redundant speed signal. To additionally verify proper calculation of wheel speed, the system is tested when the vehicle is at rest by applying an artificial sensor signal to the control input and then checking to see whether the controller determined the correct wheel speed.

Vehicle control system for determining verified wheel speed signals

A digital equivalent of a periodic analog signal is generated in a manner substantially insensitive to variations in the reference about which the analog signal oscillates by switching the digital equivalent between high and low levels based on reference voltages derived from the peaks and valleys of the analog signal. The manner of generating the digital equivalent is substantially insensitive to common mode noise across the analog signal generator by locking a differential signal output when significant common mode noise in sensed. Generator faults are also diagnosed.

Analog to digital signal conversion

A tolerance adjustment device maintains tolerances in the assembly of building panels. The tolerance adjustment device comprises a panel section which is aligned with an end edge of one building panel. An adjustment bolt moves the panel section toward and away from the end edge of the building panel to form a variable length extension of that panel which compensates for tolerance variations along the length of an assembly of the building panels.

Tolerance adjustment device

A panel locking device for assembling and interlocking two double wall panels along their adjoining edges structurally integrates the locking device within the two panels and retains the panels tightly locked together under tension under all conditions of subsequent thermal expansion and contraction. The locking device incorporates a locking pin which is driven through a lug and over a channel. Each panel has a perimeter frame. One edge of the perimeter frame of one panel forms a male channel, and the adjoining edge of the perimeter frame of the other panel forms a female channel. A lug is connected at one end to the web of the male channel. The outer end of the lug has a pin receiving and panel aligning hole extending through the lug. The web of the female channel is formed with a lug receiving slot extending through the web. An aligning and locking pin has a tapered tip; and when the panels are aligned edge-to-edge, the hole in the lug extends far enough above the backside of the female channel web to permit entry of the tapered tip of the pin. As the pin is driven into the hole and up to the full diameter of the pin, the lug is pulled upward through the slot in the female web. This produces elastic deflection of the male and female webs to retain the panels tightly locked together and structurally integrates the locking device into the perimeters of the two panels. The stressed deflection of the webs thus provides a constant and permanent force which urges the two panels together in tightly locked engagement.

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Flora, IN, United States of America

William D Wise