Abstract: An information processing system comprises: an acquisition means configured to acquire vibration of a device that vibrates during operation, as time-series data of a physical quantity A indicated by a plurality of axis components in a three-dimensional coordinate system; a calculation means configured to calculate a first evaluation value E indicating a degree of bias of the vibration of the device between axes, based on the time-series data of the physical quantity A; and an estimation means configured to estimate a degradation level G of the device based on the first evaluation value E.

Abstract: A method and a system for estimating the state of wear of a cutting tool mounted on a machine tool. The system includes an acquisition module configured to acquire, for a determined duration of machining, values of an operating signal specific to the cutting tool mounted on the machine tool, and a microprocessor configured for calculating current values of a set of wear indicators from the values of the operating signal, and determining the state of wear of the cutting tool as a function of the current values of the set of indicators using a predetermined wear model modeling the state of wear of the cutting tool in function of learning values of the set of wear indicators.

Abstract: Systems and methods of automatically operating a vehicle's hazards lights are provided. The speed of vehicle can be determined. When the speed of the vehicle is compared to an expected speed of the vehicle given various operating conditions, e.g., the output of the vehicle's engine (engine RPM) or motor (motor rotation), is slower than expected, it is assumed that the vehicle is towing a load. When the vehicle is towing a load and is also traveling at a speed that is substantially slower than the flow of traffic, a current speed limit, etc., a determination can be made to automatically activate the vehicle's hazard lights. Alternatively, even if the vehicle is towing a load, but is traveling at a speed that does not warrant activation of the vehicle's hazard lights, the hazard lights may be automatically deactivated.

Abstract: Methods and systems are provided for on-board diagnostics of components of an exhaust gas heat recovery (EGHR) system including engine coolant temperature sensors coupled to the system. Degradation of one or more of a first coolant temperature sensor coupled upstream of a heat exchanger of the EGHR system and a second coolant temperature sensor coupled downstream of the heat exchanger may be indicated based on a difference between a modeled coolant temperature and a measured coolant temperature, the modeled coolant temperature based on one or more of heat transfer between a heater core and vehicle cabin, and heat transfer between exhaust flowing via the heat exchanger and coolant flowing through the heat exchanger.

Abstract: An apparatus and method that detect a condition of a vehicle component are provided. The method includes diagnosing vehicle health of a vehicle by analyzing one or more from among vehicle performance, vehicle energy usage, and vehicle vibration and acoustics, performing fault isolation on the vehicle to detect a health condition of a vehicle component corresponding to the isolated fault if the vehicle health below a predetermined threshold, monitoring the vehicle component corresponding to the isolated fault and estimating a remaining useful life of the vehicle component corresponding to the isolated fault, and performing one or more from among continuously monitoring, scheduling maintenance, providing a warning, and performing fault mitigation based on the estimated remaining useful life of the vehicle component corresponding to the isolated fault.

Abstract: Disclosed herein are a vehicle control apparatus and a control method thereof. The vehicle control apparatus includes an input unit configured to receive a current yaw rate value, a current steering angle value, and a current lateral acceleration value detected by a detection device, an estimator configured to obtain an estimated lateral acceleration value of lateral acceleration estimation model information on the basis of the received current yaw rate value and current steering angle value, a determiner configured to determine that the current lateral acceleration value is abnormal when the received current lateral acceleration value is not equal to the estimated lateral acceleration value of the lateral acceleration estimation model information, and a controller configured to receive the current yaw rate value, the current steering angle value, and the current lateral acceleration value, deliver an estimation command to the estimator, and deliver a determination command to the determiner.

Abstract: A method for estimating the state of a moving system, using a particle filter. The method implements on one reference particle an estimation of the state and includes a first set of variables and a second set of variables. A random mutation, by the particle filter, of the first set of variables is performed followed by parameterization of an extended Kalman filter using the mutated first set of variables. The Kalman filter produces a new particle using the second set of variables and data measured by at least one sensor. The second set of variables includes at least the variables: orientation, speed and position of the moving system. The Kalman filter is configured assuming that the pair of variables orientation and position has a property of invariance upon a rotation or translation and their orientation and speed has a property of invariance on application of a rotation or translation.

Abstract: A method of parameterization of traction force interrupted shifts in a transmission of a commercial vehicle having a frame, a cab supported by the frame, and a trailer coupled to the frame. The method includes a mathematical model which considers movement equations and geometrical parameters of the frame, the cab, and the trailer. Traction force patterns of traction force interrupted shifts are predetermined which depend on a traction force decrease time, a shift time, and a traction force increase time. From model and force patterns, vibration behaviors of the cab as the output parameter of the model is simulated. The parameterization of traction force interrupted shiftings takes place such that, as the shifting parameters, the traction force decrease time, the shift time, and the traction force increase time of such force patterns are determined, for which a defined evaluation criterion of the simulated vibration behavior of the cab is optimal.

Abstract: This application relies on terminology found in the Vehicle State Detection (STATE) patent and describes methods of detecting acceleration, deceleration, accidents and cornering operational states, which we will also call vehicle dependent states, and vehicle independent states, triggered when the portable device is moved independently of movement of the vehicle. These methods enhance classification of driving behavior.

Abstract: A sensor device, such as a torque sensor, of a motor control device or an electric power steering apparatus includes a sensor section that detects a quantity of state of a detection subject and outputs a detection signal corresponding to the detected quantity of state. When receiving a specific trigger transmitted from an external device, the sensor section outputs an abnormality diagnosis signal, which is configured by a predetermined waveform and used for determining whether there is an output abnormality of the sensor section, and then outputs the detection signal.

Abstract: A method and a system for determining a running resistance Fres for a vehicle. A model-based running resistance Fres,mod is estimated. Thereafter an energy change difference ?Wdiff between a model-based estimated energy change ?Wpred and an actual energy change ?Wreal is determined for the vehicle from a starting point to an end point of a distance S which is traveled by the vehicle. A braking force Funknown which is unknown to the model and which acts upon the vehicle over the distance S is also determined on the basis of the energy change difference ?Wdiff. Thereafter the running resistance Fres is determined to an adjusted value of the model-based estimate of the running resistance Fres,mod, the adjustment being based on the braking force Funknown which is unknown to the model.

Abstract: In one aspect, a digital engine control system for an aircraft engine is provided. The control system includes a selection unit, the selection unit including a monitoring module configured to determine a measurement of the speed of rotation of the engine from the output signal from one or more protection sensors and to compare the or each speed measurement determined by the selection unit with speed measurements supplied by electronic control units to determine an operating state of each electronic control unit.

Abstract: An avionic system including: a memory that stores a selectable hash table assigned to a flight plan of an aircraft fleet, the hash table including table elements with operational parameters of an airport, wherein airports covered by the table elements are airports flown to according the fight plan of the aircraft fleet; and a plurality of ground stations situated at the flown to airports of the fight plan, wherein the ground stations are linked via a communication network to a central processing unit; a receiver of the central processing unit that receives, via a communication network interface, a transmission from a detection device, the transmission including at least parameters regarding a time interval parameter of an airport closing and an airport identification.

Abstract: A system for detecting and diagnosing a faultive state of an airplane engine, including: at least one vibration sensor attached to an airplane; a reference model database construction unit; and a fault detection and diagnosis unit which estimates a parameter of a model, obtains a test variable and a numerator coefficient value difference of a transfer function between the models, and the covariance of parameter estimation error, and diagnoses the faultive state and the faultive cause of the airplane engine. Accordingly, the present invention can determine the faultive state and the detective cause of the airplane engine using the vibration data of the airplane engine.

Abstract: A method for detecting a failure of at least one sensor onboard an aircraft implementing wind detection is provided. The method includes measuring an airspeed of the aircraft; measuring a geographical speed of the aircraft; determining an instantaneous wind vector, based on the measured airspeed and geographical speed; establishing an instantaneous wind variation vector, based on the determined instantaneous wind vector; projecting the instantaneous wind variation vector on the direction of the vector of an air or geographical speed of the aircraft; and determining the presence of a failure based on the obtained projection.

Abstract: A method for vehicle spinout detection is described. The method includes monitoring a set of conditions. If the conditions meet a set of criteria, the method calculates a lateral factor, employing one or more past values of the lateral factor. The lateral factor indicates the vehicle's lateral velocity. Then, a spinout factor is computed based on the calculated lateral factor. The spinout factor indicates the difference between the direction of vehicle travel and the direction the vehicle is heading. If the spinout factor is above a predefined threshold value, the method generates a warning signal. A system for vehicle spinout detection is also described.

Abstract: A memory stores traveling schedule information of a vehicle without a contact wire, information on a next station located on a traveling interval and information about a plurality of traffic lights on the traveling interval temporarily, and a velocity pattern calculator for calculating a velocity pattern of the vehicle based on the traveling schedule information, the information on the next station and the information about the plurality of the traffic lights, in which the velocity pattern calculator calculates a velocity pattern which satisfies conditions that the vehicle is never stopped at a first traffic light, that when the vehicle departs from a current stop station, the vehicle is accelerated at an constant acceleration a and that after the acceleration, the vehicle travels at a constant first velocity V1.

Abstract: A method of conducting vehicle usage data analysis is provided. The method includes providing usage data about at least one vehicle to a database. The usage data may be analyzed and compared to a member of a set of vehicle development models to determine whether to update a vehicle development model. The usage data may also be analyzed to determine whether to transmit a communication to a vehicle.

Abstract: A method and system for using Equivalent Time Sampling to improve the effective sampling rate of sensor data, and using the improved-resolution data for diagnosis and control. Data samples from existing sensors are provided, where the sampling rate of the existing sensors is not sufficient to accurately characterize the parameters being measured. High-resolution data sets are reconstructed using Equivalent Time Sampling. High-resolution input data sets are used in a system model to simulate the performance of the system being measured. Results from the system model, and high-resolution output data sets from Equivalent Time Sampling, are provided to an estimator, which provides accurate estimation of measured quantities and estimation of quantities not measured. Output from the estimator is used for fault diagnosis and control of the system being measured.

Abstract: A pressure sensor diagnosis method and a common-rail-type fuel injection control device to diagnose the presence or the non-presence of an abnormality of a pressure sensor without having a dedicated circuit. A time between energizing of injectors and the occurrence of a peak counter electromotive current is measured as a valve closing time. A rail pressure with respect to the measured valve closing time is obtained as an estimated rail pressure based on a correlation between a valve closing time and the rail pressure. When an absolute value of the difference between the estimated rail pressure and an actual rail pressure is equal to or less than a predetermined error, it is determined that the pressure sensor has no abnormality. Otherwise, it is determined that the pressure sensor has an abnormality.

Abstract: A microcontroller having a computing unit and a logic circuit. The microcontroller carries out computations for a regulation or control in a vehicle. The computing unit is connected to the logic circuit, and the logic circuit has an arrangement for computing an exponential function and is configurable.

Abstract: A method for determining the driving state of a vehicle in three-dimensional space comprising the steps: sensing of first signals over a specific time period, these signals being based on the first sensor signals which correspond to the three-dimensional acceleration of the vehicle; sensing of seconds signals over the specific time period, these signals being based on the second sensor signals which correspond to the three-dimensional angular rates of the vehicle; calculating the driving state variables of the three-dimensional velocity and/or three-dimensional orientation of the vehicle by integrating the first signals and or the second signals over the specific time period according to the system of equations of motion for the corresponding driving state variables; sensing of one or more third signals which are based on one or more additional third sensor signals with which one or more components of the calculated driving state variables can be determined; and correcting the first and second signals of the

Abstract: A method and system for comparing and merging fault models which are derived from different data sources. Two or more fault models are first represented as bipartite weighted graphs, which define correlations between failure modes and symptoms. The nodes of the graphs are compared to find failure modes and symptoms which are the same even though the specific terminology may be different. A graph matching method is then used to compare the graphs and determine which failure mode and symptom correlations are common between them. Finally, smoothing techniques and domain expert knowledge are used to merge and update the fault models, producing an integrated fault model which can be used by onboard vehicle systems, service facilities, and others.

Abstract: A method is provided for processing data in an influencing device, whereby the influencing device is connectable to a vehicle control unit and to a data processing unit. If the influencing device receives a first trigger or a second trigger, the first trigger is checked for a valid assignment to a function implemented in the hardware or software. If there is a valid assignment, the assigned function is started. A first address and/or a second address and/or the value are checked for a valid assignment to a first sub-function or a second sub-function. Depending on the called sub-function, the value is checked and/or manipulated and depending on the result of the check, the checked value and/or the manipulated value are sent by the influencing device to the vehicle control unit and/or to the data processing unit and/or stored in the memory of the influencing device.

Abstract: Diagnosing auxiliary equipment associated with an engine. A condition of the auxiliary equipment is diagnosed based on information provided by signals from a generator operationally connected to the auxiliary equipment or other signals associated with the engine. Different types of degradation are distinguished based on discerning characteristics within the information. Thus, a degraded auxiliary equipment component can be identified in a manner that reduces service induced delay.

Abstract: Methods and systems for prognostic condition assessment decision aid of a fleet of vehicles are disclosed. In one embodiment, a method includes providing a schedule of missions and maintenance of a fleet of vehicles, comprising receiving data from the fleet of vehicles for missions and maintenance activity, determining mission and maintenance requirements, processing the received data and requirements to provide an operational allocation of the fleet of vehicles, determining an alternative allocation of the operational allocation of the fleet of vehicles, the alternative allocation satisfying at least one operational objective for the fleet of vehicles, and generating a schedule for the alternative allocation of the fleet of vehicles.

Abstract: A navigation filter for a navigation system using terrain correlation delivering an estimation of the kinematic state of a carrier craft using a plurality of data includes the measurements returned by at least one terrain sensor, the model associated with the terrain sensor, the data from an onboard map, an error model for the onboard map, the measurements returned by an inertial guidance system, and a model of the inertial guidance system. The navigation filter also includes a first filter referred to as convergence filter, for example of the Kalman filter type, and a second filter referred to as tracking filter, for example of the particle filter type.

Abstract: A method and a device are described for scanning the surrounding environment of a vehicle. When the vehicle falls below a first boundary speed a timer is triggered whose state is incremented until the vehicle exceeds a boundary speed, a check of the unobstructed view of the scanning device being carried out upon expiration of the time period recorded by the state of the timer and in which the state of the counter is incremented.

Abstract: A method and a device for filtering diagnostic messages obtained from a plurality of elements of a system, each of these elements comprising diagnostic means capable of detecting a failure and of transmitting a message comprising at least one failure indication. The state of at least certain elements of the said plurality of elements is represented by a model of state. After at least one failure message has been received, this message is filtered according to the failure indication that it contains and according to the model of state. In response to the filtering step, the model of state is updated according to the failure indication or the message is rejected. The filtering step is advantageously based on a propositional logic mechanism.

Abstract: A method and apparatus for automatically calibrating vehicle parameters is described. In one embodiment, the method includes measuring a parameter value during vehicle operation; comparing the measured parameter value to an actual parameter value to identify at least one vehicle parameter bias as an actual measurement error; and modifying at least one vehicle parameter based on the at least one vehicle parameter bias.

Abstract: When anomalous vehicle actions occur in a vehicle multiple times, it is determined whether each action data is included in a series of action data sets that are closely related mutually or an irrelevant independent action data set. When it is included in the series of action data sets, the ECUs record the series of action data sets in respective own memories according to a predetermined recording order. In contrast, when it is included in the independent action data set, an earliest ECU that is earliest in the recording order records the action data by overwriting its own memory. In this case, the earliest ECU transmits an instruction to other ECUs to delete all past action data that are recorded in own memories of the other ECUs.

Abstract: A system and method for fault diagnosis includes receiving information defining a relationship between failure modes and diagnostic trouble codes and extracting diagnostic trouble code data, including set times, frequency data and diagnostic trouble code sequence information for a plurality of diagnostic trouble codes relating to a plurality of failure modes. The system and method further include constructing a Markov chain using the diagnostic trouble code data for each of the plurality of failure modes, training the Markov chain to learn a set of state parameters using the diagnostic trouble code data, and computing a likelihood of a diagnostic trouble code sequence for each of the plurality of failure modes using the trained Markov chains.

Abstract: A controller for determining whether a previously-detected vehicle malfunction still exists. If the malfunction is no longer detected in the sensor signals, a vehicle control system operates in a first operational state or normal operational state with respect to the previously-malfunctioning sensor (e.g., signals from the sensor are used to control the vehicle). If the malfunction continues to be detected, the vehicle control system operates in a second operational state or malfunction state with respect to the malfunctioning sensor in which the signals from the sensor are not used to control the vehicle.

Abstract: A method and systems for controlling an engine are provided. The system includes an engine model programmed to receive engine operating condition values from a plurality of sensors on an engine. The engine model is programmed to determine a plurality of engine operating parameter values. The system also includes a processor configured to compare the operating parameter values to a predetermined allowable range for the operating parameter and control the operation of the engine to facilitate returning the determined operating parameter to the allowable range or maintaining the determined operating parameter within the allowable range, output the determined operating parameter values to a user, and/or generate maintenance requests based on the comparison.

Abstract: An improved method for predicting the health of a power transmission and an apparatus for practicing the same are provided. The method includes: monitoring a total number of converged shifts after a first shift has converged; determining if the total number of converged shifts is greater then a calibrated number of completed converged shifts; if yes, determining an initial clutch volume, an initial free running clearance, a free running clearance, and a free running clearance per face and monitoring a change in free running clearance per face; determining if either the free running clearance per face is greater than a calibrated free running clearance per friction surface for failure or if the change in free running clearance per face is greater than a calibrated change in free running clearance per friction surface for failure; if yes, activating a service indicator configured to warn vehicle occupants that transmission service is required.

Abstract: A method and system is developed that provides a confidence measure of a prediction of a fault in a gas turbine engine. The confidence measure is developed based upon evaluating the results of a plurality of past predictions and comparing them to an actual fault.

Abstract: In a method and a device for increasing the precision of the position determination of a motor-driven closure element of a vehicle, the data corresponding to a force-displacement reference curve and the data corresponding to a force-displacement actual value curve are used, a correlation function is calculated, the maximum thereof is found, and the counter status of a position counter is corrected by using the position offset associated with the determined maximum.

Abstract: The vehicle inspection apparatus is for inspecting behavior of at least one control object mounted on a vehicle whose behavior is controlled through behavior control performed by a control section included in a control system mounted on the vehicle in accordance with a behavior request inputted from an external device. The vehicle inspection apparatus includes a behavior judging section to judge whether or not the control object is abnormal on the basis of a detected behavior value of the control object and an estimated behavior value of the control object, whose dimensions have been matched with each other.

Abstract: Precise operation of an accelerator operating member (7) is more difficult to perform in a reversing operation of a vehicle (1) as compared with an advancing operation. Therefore, behavior of the vehicle (1) is not smooth and thus tends to be unnatural. In the reversing operation of the vehicle (1), driving force output from an internal combustion engine (2) is limited in accordance with vehicle acceleration (D). At this time, it is possible to regulate the driving force of the vehicle (1) in conformity to the actual operation of the accelerator operating member (7) by the driver. In addition, limitation of the driving force is not executed in the advancing operation of the vehicle (1). At this time, the vehicle (1) can be driven in a state in which the driving force is comparatively small. Therefore, it is possible to prevent the behavior of the vehicle (1) from being unnatural.

Abstract: A method and apparatus for automatically calibrating vehicle parameters is described. In one embodiment, the method includes measuring a parameter value during vehicle operation; comparing the measured parameter value to an actual parameter value to identify at least one vehicle parameter bias as an actual measurement error; and modifying at least one vehicle parameter based on the at least one vehicle parameter bias.

Abstract: A method of conducting vehicle usage data analysis is provided. The method includes providing usage data about at least one vehicle to a database. The usage data may be analyzed and compared to a member of a set of vehicle development models to determine whether to update a vehicle development model. The usage data may also be analyzed to determine whether to transmit a communication to a vehicle.

Abstract: A method and tools for virtually aligning object detection sensors on a vehicle without having to physically adjust the sensors. A sensor misalignment condition is detected during normal driving of a host vehicle by comparing different sensor readings to each other. At a vehicle service facility, the host vehicle is placed in an alignment target fixture, and alignment of all object detection sensors is compared to ground truth to determine alignment calibration parameters. Alignment calibration can be further refined by driving the host vehicle in a controlled environment following a leading vehicle. Final alignment calibration parameters are authorized and stored in system memory, and applications which use object detection data henceforth adjust the sensor readings according to the calibration parameters.

Abstract: A method and system for using Equivalent Time Sampling to improve the effective sampling rate of sensor data, and using the improved-resolution data for diagnosis and control. Data samples from existing sensors are provided, where the sampling rate of the existing sensors is not sufficient to accurately characterize the parameters being measured. High-resolution data sets are reconstructed using Equivalent Time Sampling. High-resolution input data sets are used in a system model to simulate the performance of the system being measured. Results from the system model, and high-resolution output data sets from Equivalent Time Sampling, are provided to an estimator, which provides accurate estimation of measured quantities and estimation of quantities not measured. Output from the estimator is used for fault diagnosis and control of the system being measured.

Abstract: In a vehicle control device capable of sufficiently exhibiting the effect of vehicle control, a selection section selects a value greater than an intermediate value of a vehicle weight in a range restricted by a range restriction unit as the value of the vehicle weight and selects a value greater than an intermediate value of the height of the center of gravity in the range as the value of the height of the center of gravity. For stability, the greater the height of the center of gravity of the vehicle is, the stricter the conditions that are imposed. For fuel consumption, the greater the vehicle weight is, the stricter the conditions that are imposed. The selection section selects the values which become conditions stricter than at least an intermediate value in the range restricted by the range restriction section, and the range restriction section restricts the range.

Abstract: A method for use in evaluating an operation of a combustion machine. A plurality of current average intensities is calculated by a computing device based on a series of intensity readings from a flame sensor. Each current average intensity corresponds to a current time interval. The computing device selects a plurality of past average intensities, each of which corresponds to a past time interval equal in duration to the current time interval corresponding to a current average intensity. The computing device calculates a plurality of decay rates indicating a change in intensity readings over a current time interval based on the current average intensities and the past average intensities. The computing device estimates a predicted flame sensor malfunction time based on the plurality of decay rates.

Abstract: A method for vehicle spinout detection is described. The method includes monitoring a set of conditions. If the conditions meet a set of criteria, the method calculates a lateral factor, employing one or more past values of the lateral factor. The lateral factor indicates the vehicle's lateral velocity. Then, a spinout factor is computed based on the calculated lateral factor. The spinout factor indicates the difference between the direction of vehicle travel and the direction the vehicle is heading. If the spinout factor is above a predefined threshold value, the method generates a warning signal. A system for vehicle spinout detection is also described.

Abstract: An interface device includes a processor, a memory communicating with the processor and containing indicators of vehicle operational parameters from which a user may select to set up filters, a communication module communicating with the processor, and a plurality of protocol bus modules supporting different multiple vehicle diagnostic protocols and have multiple filters for set up in correspondence with the indicators of user-selected parameters. The processor is configured to control the memory and modules to cooperate with one another to find the correct protocol out of multiple supported protocols, define the indicators of user-selected parameters by saving user-initiated filter setups, read data regarding user-selected parameters from a vehicle diagnostic communication port according to the filter setups, and output messages regarding the user-selected parameters.

Abstract: A yaw-rate forecasting system for a vehicle. The system includes a yaw rate sensor and an electronic control unit. The yaw rate sensor is configured to detect a yaw rate of the vehicle and to generate a signal indicative of the detected yaw rate. The electronic control unit is coupled to the yaw rate sensor, and is configured to receive the signal indicative of the yaw rate of the vehicle from the yaw rate sensor, forecast a future yaw rate, determine a stability of the vehicle using the forecasted yaw rate, and to generate a signal to control actuation of a vehicle brake.

Abstract: A method and system for developing fault models from structured text documents, such as service procedures. A service procedure or other structured text document is parsed using diagnostic rules to extract symptoms, failure modes, and correlations. Testing procedures and repair instructions are also parsed to create a fault tree and identify additional symptoms and failure modes. Reachability analysis is then used to find hidden dependencies in the fault tree, thus yielding additional correlations. The resultant symptoms, failure modes, and correlations are then assembled into a fault model, which can be used for real-time fault diagnosis onboard a vehicle, or for off-board diagnosis at service shops.

Abstract: A method for monitoring the sensors in a vehicle control system. The method includes identifying a plurality of potential faults, identifying a plurality of measured values, and identifying a plurality of estimated values based on models in the control system. The method further includes identifying a plurality of residual error values as the difference between the estimated values and the measured values. The method also defines a plurality of fuzzy logic membership functions for each residual error value. The fuzzy logic membership functions are adaptive in that they change depending on the vehicle operating region, i.e., the non-linearity level of the vehicle, and the vehicle operating conditions, i.e., steady state verses transients. A degree of membership value is determined for each residual error value based on the membership functions. The degree of membership values are then analyzed in a fuzzy logic reasoning system to determine whether a potential fault exists.