Abstract: A method of statistically characterizing combustion knock events includes receiving signals from a sensing device such as an accelerometer, estimating at least one parameter of a probability distribution function based on the received signals, and calculating a value indicative of an nth percentile based on the parameter to predict upcoming combustion knock events.

Abstract: A method of statistically characterizing combustion knock events includes receiving signals from a sensing device such as an accelerometer, estimating at least one parameter of a probability distribution function based on the received signals, and calculating a value indicative of an nth percentile based on the parameter to predict upcoming combustion knock events.

Abstract: An apparatus and method for operating a plurality of valves in an engine uses valve actuators to move each valve. Accelerometers are used to detect acceleration of the valves and particularly the moment when they seat. A knock sensor detects an acoustic impulse made by the valves when they seat. A controller correlates signals from the sensor and accelerometers, wherein a signal from the sensor that correlates in time with a signal from an accelerometer indicates seating of the respective valve, which indicates a closure of the respective valve. The controller measures a magnitude of the acoustic impulse to be used as feedback in controlling the operation of the respective valve actuator, and provide softer landings of the valve.

Abstract: A method and system for a misfire detection acquires (301) a series of acceleration data (302) representative of acceleration behavior of an engine. The data is sampled (304) to obtain acceleration data samples at a rate sufficient to obtain up to fourth-order perturbations of the data. The samples are filtered (322) to provide bandwidth limited samples, which are provided to at least two channels (325, 329). The samples are pattern matched (332) in a first channel to enhance harmonic phenomena and pattern canceled (330) in a second channel to enhance random phenomena. Hard and random misfires are detected (334) dependent on a magnitude of the filtered acceleration data samples. Preferably, a third channel (335) is added to detect multiple misfires.

Abstract: An electronic throttle controller (200) includes a feedforward control (222), a PID (224), a sliding mode control (226) and an adder (230). The PID (224) is capable of generating a first feedback term that compensates for an error signal. The sliding mode control (226) is capable of generating a second feedback term that incorporates a solution to a Lyapunov equation applied to the error signal with sliding gain being updated by an estimation of unknown dynamics. The adder (230) adds the first feedback term, the second feedback term and the feedforward control (222) so as to generate a control signal (232).

Abstract: An electronic throttle controller (200) includes a feedforward control (222), a PID (224), a sliding mode control (226) and an adder (230). The PID (224) is capable of generating a first feedback term that compensates for an error signal. The sliding mode control (226) is capable of generating a second feedback term that incorporates a solution to a Lyapunov equation applied to the error signal with sliding gain being updated by an estimation of unknown dynamics. The adder (230) adds the first feedback term, the second feedback term and the feedforward control (222) so as to generate a control signal (232).

Abstract: A method for monitoring the performance of a catalytic converter (34) computes the oxygen storage capacity and desorption capacity of a catalyst within the catalytic converter (34). An engine control unit (10) receives mass flow rate information of air from a mass air flow rate sensor (12) and an injector driver (24), and receives electrical signals from an upstream exhaust gas sensor (28) and a downstream exhaust gas sensor (30). A rate modifier is determined from excess air ratios and an adaptation parameter. The engine control unit (10) calculates normalized air fuel ratios for the exhaust gas entering and leaving the catalytic converter (34) and performs numerical integration using the rate modifier to determine the oxygen storage capacity of the catalyst in the catalytic converter (34). The calculated oxygen storage capacity of the catalyst can be compared with threshold values to determine the performance of the catalytic converter (34).

Abstract: A method and apparatus converts time-resolved sensor signals into transfer functions and/or cumulative transfer function signals which can be attained by computation means such as by using Fast Fourier Transforms. A signal, as a means to assess catalyst performance such as a signal based on sensing oxygen concentration or air to fuel ratio or hydrocarbon concentration in motor vehicle exhaust in accordance with the present invention is in the time domain and has multiple components at different frequencies. The use of Fast Fourier Transforms isolates the various spectral densities which arise from different frequency components of the complex time domain signal. Cross spectral density function and power spectral density function are used to determine the transfer function. The analysis has been found to be substantially independent of operating conditions. The transfer function and cumulative transfer function have been found to be a precise indication of the catalyst performance.

Abstract: A system and method measures hydrocarbon conversion efficiency of a catalytic converter (501). Total-combustible sensors (511, 521) are positioned to measure exhaust gas on both sides of the catalytic converter (501). Signals from these sensors (511, 521) have a magnitude comprised of a first portion, dependent on a concentration of the hydrocarbon gas in the gas stream, and a second portion, dependent on a concentration of the other combustible gasses in the gas stream, where a magnitude relationship between the first portion and the second portion is variable when the gas stream transitions into a region on the rich side of stoichiometry. The signals from these sensors (511, 521) are filtered so that a magnitude relationship between a first and second portion of the filtered signals is constant when the gas stream (506) transitions into the region on the rich-side of stoichiometry. Hydrocarbon conversion efficiency (529) is computed dependent on the filtered signals (515, 525).

Abstract: A system and method estimates tailpipe emissions by sensing (703) a catalyzed gas stream (506) and providing a total-combustible gas signal (511) dependent thereon. The total-combustible gas signal (511) has a magnitude comprised of a first portion, dependent on a concentration of the hydrocarbon gas in the catalyzed gas stream (506), and a second portion, dependent on a concentration of the other combustible gasses in the catalyzed gas stream (506). A magnitude relationship between the first portion and the second portion is variable when the catalyzed gas stream (506) transitions into a region on the rich side of stoichiometry. The variability the magnitude relationship of the first and second portions is filtered out so that the magnitude relationship is substantially constant when the catalyzed gas stream (506) transitions into the region on the rich side of stoichiometry.

Abstract: A method for monitoring and controlling the performance of a catalytic converter (34) includes monitoring an exhaust gas stream from an engine (16) for the presence of methane. Upon detecting methane in the exhaust gas stream an oxygen storage level of a catalyst within the catalytic converter (34) is determined. The oxygen storage level is compared with a reference standard and the air/fuel ratio of the exhaust gas stream is continuously adjusted to maintain the oxygen storage level within predetermined control limits.

Abstract: A method for monitoring the performance of a catalytic converter includes the monitoring of output from a first gas sensor (16) positioned upstream from a catalytic converter (12) and a second gas sensor (18) located at a position downstream from the catalytic converter (12). An engine controller (20) receives the output of the first and second gas sensors (16,18) and also receives estimates of the exhaust gas mass flow rate and the catalyst temperature within the catalytic converter (12). The exhaust gas mass flow rate and the catalyst temperature are used to calculate a mass transfer coefficient that is determinative of the conversion efficiency of the catalytic converter (12). A monitoring parameter is determined using the output of the first and second gas sensors (16,18), and the monitoring parameter is normalized to the coefficient.