Redundant Wheel Speed Sensor Architecture for ECU and ASIC Failures
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Solution Overview
Problem
Existing wheel speed sensor systems lack redundancy to compensate for component failures, which can compromise safety in autonomous vehicles by disrupting brake control systems.
Innovation Solution
A wheel speed sensor system with dual redundant components, including two sets of sensors, application-specific integrated circuits (ASICs), and electronic control units (ECUs), connected via direct data links and a CAN bus, ensuring that wheel speed data can be received and processed even if one ECU or ASIC fails, thereby maintaining control over controllable devices like electric motors or valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single ECU and ASIC are used in the wheel speed sensor system, then the device complexity is low, but the reliability is insufficient to compensate for component failures
Solution Approach 1:
The system is divided into two independent channels, each with its own ECU and ASIC. The first ECU (6) and first ASIC (4) form one channel, while the second ECU (7) and second ASIC (5) form another channel. This segmentation allows one channel to take over if the other fails, resolving the contradiction by improving reliability through redundancy while maintaining manageable complexity through modular design
Solution Approach 2:
Different parts of the system have different connection configurations. The ASICs have direct data links to both ECUs, while the ECUs communicate through a CAN bus. This local differentiation optimizes the redundancy architecture, allowing each component to have the specific connectivity needed for its function, thereby improving overall system reliability without uniformly increasing complexity throughout the entire system
2Reliability
If redundant components are added to the wheel speed sensor system, then the reliability improves, but the device complexity increases
Solution Approach 1:
Both ECUs are designed with identical functionality to process wheel speed data from either ASIC. Each ECU can independently receive data from both ASICs through the CAN bus, and both can control the controllable device. This universality allows the system to maintain full functionality with redundant components, improving fault tolerance while keeping the architecture manageable through standardized designs
Solution Approach 2:
The CAN bus acts as an intermediary communication medium between the ECUs and ASICs, enabling flexible data routing. Through this intermediary, each ECU can receive wheel speed data from either or both ASICs, and the system can dynamically route data around failed components, improving reliability while abstracting the complexity of redundant component management
Data Source
AI summary
The present disclosure relates to a wheel speed sensor system (1), comprising: one or more first wheel speed sensors (2a, 2b), a first application specific integrated circuit (ASIC) (4) configured to receive one or more first wheel speed signals from the one or more first wheel speed sensors (2a, 2b) and to convert the one or more first wheel speed signals to first wheel speed data, and a first electronic control unit (ECU) (6) configured to receive the first wheel speed data from the first ASIC (4) via a data link (8) between the first ECU (6) and the first ASIC (4); and one or more second wheel speed sensors (3a, 3b), a second ASIC (5) configured to receive one or more second wheel speed signals from the one or more second wheel speed sensors (3a, 3b) and to convert the one or more second wheel speed signals to second wheel speed data, and a second ECU (7) configured to receive the second wheel speed data from the second ASIC (5) via a data link (9) between the second ECU (7) and the second ASIC (5). The first ECU (6) is further configured to receive the second wheel speed data from the second ASIC (5) via a data link (13) between the first ECU (6) and the second ASIC (5), and the second ECU (7) is further configured to receive the first wheel speed data from the first ASIC (4) via a data link (14) between the second ECU (7) and the first ASIC (4). The present disclosure further relates to a vehicle including said wheel speed sensor system and to a method of processing wheel speed signals.