Showing papers by "Giorgio Rizzoni published in 1990"

Method and system for detecting the misfire of an internal combustion engine utilizing angular velocity fluctuations

Abstract: A hybrid method and system are disclosed for the detection of internal combustion engine misfires. The method and system are capable of detecting misfires even at very low occurrence rates in real time with inexpensive analog and digital (i.e. hybrid) electronics suitable for use on-board a vehicle, thus satisfying current and proposed exhaust emission control regulations. The method and system exploit a measurement of engine crankshaft angular velocity in conjunction with hybrid electronic signal processing. Once the angular velocity signal is conditioned to minimize the effects of random error and external disturbances, four alternate computationally efficient methods may be used to extract information pertaining to individual cylinder torque productions. Two of the methods employ extremal samples of the estimated torque or velocity waveform to obtain a random torque nonuniformity index or metric. The other two methods utilize a transformation into the frequency domain after the input data is first sampled and windowed to substantially lower probability of error. All of the methods provide an M-dimensional torque non-uniformity vector of individual cylinder performance for each individual engine cycle. The non-uniformity vector represents a compact and efficient measurement to which statistical decision theory is applied.

The Distinction between a Special Class of Multiplicative Events and Additive Events: Theory and Application to Automotive Failure Diagnosis

Abstract: In this paper, we construct a suboptimal generalized likelihood ratio to distinguish between a change in the operating point of an internal combustion engine and a class of actuator failures. The problem is formulated as a binary decision problem between a known multiplicative event and a partially unknown additive event. The resulting algorithm ia simulated and verified using engine models for a number of noise realisations. Both known and unknown event onset times are considered.

An IBM PS/2 based general purpose engine analyzer

Abstract: Novel concepts in the design of hardware and algorithms for the diagnosis of a broad range of engine malfunctions and an architecture for general purpose engine analyzers which is based on a clock and sampling signal based on engine angular position are described. The system is based on an IBM PS/2 model 70 portable, chosen for its power, portability, and compatibility with existing PC systems. The system features a number of original algorithms. The scheme consists of an analog preprocessing system which considerably lightens the computational burden of the CPU, and of a set of fast algorithms for the estimation of individual cylinder-produced torque and the instantaneous detection of misfiring cylinders. Among the functions performed by the analyzer are idle speed stability and cylinder power balance, misfire detection, compression checks, fuel injector diagnostics, 0/sub 2/ sensor and catalyst diagnostics. In addition, the data acquisition hardware is compatible with the implementation of model-based detection filters, useful for the diagnosis of sensor and actuator failures. >

Design of Strong Detection Filters by Eigenvector Assignment: Theory and Application to Real Time Automotive Failure Diagnosis

Abstract: Considerable attention has recently been devoted by a number of researchers to the design of Failure Detection Filters using the tools of modern control theory. The original results obtained by Beard [1] and Jones [2] in the early 70's have been revised and expanded by Meserole [3], Chow and Willsky [4], White [5], Massoumnia [6], and more recently by Mi [71The common thread in the various methods proposed is the structure of the detection filter, which is that of a state estimator. Typically, in a detection filter the failure event is modeled as an additive term in the state equation for the error residuals, and the feedback gains are then selected to force a given failure residual to lie in a known, unique direction in output space. Recently, the application of these ideas has proven successful in the case of electronically controlled internal combustion engines [7],[8]49]. Parallel to the development of a theory for the design of detection filters, the results of Moore 112] and others (more recently Kwon and Youn [11]) have focused on eigenstructure gnment for application to the design of feedback controlers. This problem is, in a sense, dual to the detection filter design problem. The present note discusses the improved robustness of a detection filter design based on eigenvector assignment techniques. The main improvement with respect to previous techniques, in particular those developed by Min [7] and White [5], is that the possibility of having different failures produce residuals with the same direction in output space is greatly reduced. In Section 2 we will define the system under consideration. In Section 3 Strong Detectability will be introduced, and in Section 4 a theory wil be developed to support the notion of a strong detection operator. The method is illustrated by way of an application in section 5. The application is based on the design of detection filter which can discriminate between certain plant and component failures.