Model-Based Fault Detection and Isolation in Automotive Electrical Systems

Abstract

This paper deals with the design and validation, through simulation in a Matlab/Simulink and SABER environment, of model-based diagnostic algorithms for an automotive electric power generation system (EPGS). The EPGS includes alternator with rectifier, a battery, and a voltage regulator. The mathematic models of these subsystems, based on the physics of the processes involved, consist of time-varying nonlinear ODEs. The diagnostic problem focuses on the detection and isolation of a specific set of alternator faults, including belt slipping, rectifier fault and voltage regulator fault. An in-depth analysis of the models is conducted in order to understand the effects of different failure modes on system performance; subsequently, an equivalent input-output model of the alternator is formulated and parameterized. The equivalent model permits considerable simplification of the algorithms. The proposed diagnostic approach is based on the generation of residuals obtained using system models and comparing the predicted and measured value of selected variables, including alternator output current, field voltage, battery current, battery voltage and battery temperature. This paper presents the models, diagnostic algorithms and simulation results.

Design and Selection of Additional Residuals to Enhance Fault Isolation of a Turbocharged Spark Ignited Engine System

“…As a result, a fault that is present in the engine system can trigger several monitors or manifest into other types of faults, hence affecting fault isolation performance of the diagnostic systems [11]. This is critical as the ability to identify and isolate the root fault from the manifested faults enables the replacement of the correct faulty components to enhance the reliability of the overall system [12]. This also helps to ensure the safety of the occupants onboard the vehicle as well as other road users.…”

Diagnosis of an Alternator System Using Quantized Approaches

“…A healthy EPGS system is crucial for proper operation of a vehicle and have been investigated in previous literature. Scacchioli, Rizzoni, and Pisu (2006) proposed a fault isolation approach for an EPGS system using two equivalent alternator models. One equivalent model for a healthy alternator and one equivalent model for an alternator with one broken diode.…”

Interpolated FFT for real-time detection of belt slip in automotive electric power generation and storage system

“…A simplified linear dynamic model of the alternator was proposed to detect belt slip by modeling the relationship between the field excitation and output current [3]. But the method is sensitive to modeling errors and load variations.…”

“…A failure of such alternator may leave a motorist stranded [3][4]. Timely and accurate detection of alternator problems will not only decrease "walk-home" incidences but will also significantly decrease misdiagnoses, thereby resulting in significant warranty cost savings for auto manufacturers [3][4][5][6][7][8][9][10][11][12][13].…”

“…While there has been active research in the sensorless condition monitoring of induction and permanent-magnet machines [14][15][16][17][18], [23], there exist only a few literatures on the condition monitoring of claw-pole alternators [3][4][5][6], and more specifically, on the detection of belt slip [3], [6]. A simplified linear dynamic model of the alternator was proposed to detect belt slip by modeling the relationship between the field excitation and output current [3].…”