Diagnostic Circuitry for Powered Sensor Fault Identification
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Solution Overview
Problem
Conventional diagnostic systems for machine systems struggle to uniquely identify faults such as open wire connections, series resistance, and resistance to ground or voltage source in sensor wires, often misinterpreting system malfunctions due to distorted pulse width modulation signals and inability to differentiate between operational and fault states without rotating the motor.
Innovation Solution
A diagnostic interface system with coordinated voltage divider networks between powered sensors and electronic control units (ECUs) generates unique steady-state voltage levels for each fault and operating condition, enabling fault-tolerant detection of open wire connections, series resistance, and resistance faults through analog input ports, using resistor bias networks and adaptive signal processing to distinguish between operational and fault states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional diagnostic systems are used, then the system can detect sensor faults, but it cannot uniquely identify specific fault conditions such as open wire connections, series resistance, and resistance to ground or voltage source
Solution Approach 1:
The patent segments the diagnostic process into multiple distinct voltage level measurements (at least two different voltage levels) to differentiate between various fault conditions. By dividing the diagnostic approach into separate measurement stages with different voltage divider configurations, the system can uniquely identify specific fault types such as open wire connections versus resistance faults.
Solution Approach 2:
The patent changes the voltage level parameter by applying at least two different voltage levels to the sensor input during diagnosis. This parameter variation allows the diagnostic system to observe different voltage divider outputs that correspond to different fault conditions, enabling unique identification of fault types that would be indistinguishable at a single voltage level.
2Reliability
If the system requires motor rotation to differentiate operational and fault states, then fault detection can be performed, but system productivity and ease of operation are reduced
Solution Approach 1:
The patent performs preliminary diagnostic actions by measuring voltage levels at the ECU before any motor rotation or sensor operation is required. The voltage divider network provides immediate fault indication through steady-state voltage measurements, allowing the system to identify faults without requiring the motor to rotate or the sensor to be in a specific operational state.
Solution Approach 2:
The patent extracts the fault detection function from the motor operation requirement. By using a separate voltage divider diagnostic circuit that operates independently of motor rotation, the system can identify faults without requiring the main motor-driven system to be in motion, thus maintaining productivity while ensuring reliability.
3Measurement precision
If the digital interface is not fault tolerant, then the circuit is simpler, but the system cannot identify faults un-mistakably
Solution Approach 1:
The patent implements feedback through the voltage divider network that provides distinct voltage level responses to different fault conditions. The ECU monitors these voltage levels and uses the feedback information to uniquely identify fault types. This feedback mechanism ensures that fault identification is unmistakable, with each fault condition producing a characteristic voltage pattern that the digital interface can recognize and report.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively identifies and separates fault conditions, enhancing reliability and safety by providing unmistakable fault identification without requiring motor rotation, reducing warranty costs and improving system reliability.
Implementation Method 1
coordinated voltage divider networks between powered sensors and electronic control units (ECUs) generates unique steady-state voltage levels for each fault and operating condition
Implementation Method 2
via resistor bias networks between the powered sensor and the ECU... produces a series of unique voltage levels
Data Source
AI summary
A sensing system includes circuitry having a diagnostic interface for a powered sensor. Responsive to sensing signals, the circuitry is operable to produce a DC level that is defined by operating or fault conditions. The fault conditions include an open voltage supply, an open sensor power return signal, open communication signal(s), series resistance in a communication signal, fault resistance to ground on the communication signal and fault resistance to a voltage source on the communication signal. The circuitry includes a fault tolerant interface between a wire harness at an output of the powered sensor and a digital input port of a microprocessor for the purpose of un-ambiguous fault detection when distortion of sensor information occurs or when loss of sensor information occurs, and wherein the microprocessor diagnoses a fault as defined by the DC level of the analog signal monitored at the communication signal input to the microprocessor.