Sensor Circuit Inter-Sensor Short Detection
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Solution Overview
Problem
Existing sensor circuits in automotive applications are unable to detect short circuits between wheel-speed sensors or channels, particularly in dynamic operational conditions, as they are designed to detect short conditions only between individual sensors and ground, not between multiple sensors or channels, and often require a static state for fault detection.
Innovation Solution
A sensor circuit with a controller and signal processing circuit that injects a test current into selected sensors while the vehicle is in motion, using leakage current detectors to identify short conditions between sensors or channels by monitoring changes in leakage current and generating compensation signals to ensure accurate signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing sensor circuits are used to detect short conditions, then short circuits between individual sensors and ground can be detected, but short circuits between multiple sensors or channels cannot be detected
Solution Approach 1:
The patent applies segmentation by dividing the detection process into multiple phases: a first mode for detecting short circuits between individual sensors and ground, and a second mode for detecting short circuits between multiple sensors or channels. This segmented approach allows the system to systematically check different fault conditions that would be impossible to detect simultaneously with a single detection method.
Solution Approach 2:
The patent implements dynamics by enabling the sensor circuit to dynamically switch between two operational modes based on detection needs. The controller can transition from the first detection mode to the second detection mode and vice versa, allowing the system to adapt its detection strategy in real-time based on the operational context and suspected fault conditions.
2Reliability
If sensor circuits require static state for fault detection, then detection can be performed, but detection during dynamic vehicle operation is not possible
Solution Approach 1:
The patent resolves this contradiction by making the detection system itself dynamic. The sensor circuit is designed to perform fault detection while the vehicle is in motion by continuously monitoring sensor signals and comparing them against expected patterns. The system dynamically adjusts its detection thresholds and analysis methods based on real-time operating conditions, enabling accurate fault detection regardless of vehicle state.
Solution Approach 2:
The patent applies preliminary action by implementing continuous monitoring and preliminary analysis of sensor signals during normal operation. The controller continuously compares sensor outputs against expected ranges and patterns, preparing detection data in real-time so that when a fault condition occurs, the system can immediately identify it without requiring the vehicle to stop or enter a static state.
3Device complexity
If traditional sensor circuits are used, then simple short-to-ground detection is possible, but inter-sensor short circuit detection is not possible
Solution Approach 1:
The patent applies segmentation by separating the detection functionality into distinct operational modes within the controller. The first mode handles simple short-to-ground detection using traditional methods, while the second mode implements inter-sensor short circuit detection by comparing signals across multiple sensors. This segmented implementation allows the system to maintain circuit simplicity for basic detection while adding enhanced detection capabilities when needed.
Solution Approach 2:
The patent implements universality by designing the sensor circuit and controller to perform multiple detection functions using the same hardware components. The controller is programmed to execute different detection algorithms and modes, enabling it to detect both simple short-to-ground conditions and complex inter-sensor short circuits without requiring separate dedicated circuits for each function.
Data Source
AI summary
A sensor circuit, including at least a first sensor arranged to selectively receive a first test current; a first digital-to-analog converter, DAC, arranged to receive a first signal from the first sensor and output a first compensation signal in response thereto; a second DAC arranged to receive a second signal from a second sensor and output a second compensation signal in response thereto; and a controller operably coupled to the first and second DACs and operable to determine from at least one of: the first compensation signal and second compensation signal whether a short condition exists between the first sensor and the second sensor.