Functional safety is a critical aspect of autonomous electric vehicle development. It ensures that systems operate safely even when component failures occur. In autonomous vehicles, functional safety addresses potential hazards from sensor malfunctions, software errors, and power system failures. The goal is to identify risks early and implement safety mechanisms that prevent accidents, making autonomous vehicles reliable and trustworthy for public use.
ISO 26262 is the international standard for functional safety in automotive systems. It defines a comprehensive safety lifecycle from concept through production. The standard introduces Automotive Safety Integrity Levels, or ASIL, ranging from A to D, where ASIL D represents the highest risk requiring the most stringent safety measures. The V-model development process ensures safety requirements flow from initial concept through implementation and back up through validation and verification phases.
危害分析和风险评估过程，简称HARA，是ISO 26262标准的基础。它系统地识别无人驾驶汽车系统中的潜在危害，并评估其风险。风险通过三个参数计算：潜在伤害的严重性、暴露频率和驾驶员或系统的可控性。常见危害包括传感器故障、软件故障和电力系统问题。HARA过程基于此风险评估分配ASIL等级，确定所需的安全措施。
Safety architecture design implements multiple layers of protection for autonomous electric vehicles. Key principles include redundancy, where backup systems take over when primary systems fail, diversity using different technologies for the same function, and fail-safe mechanisms that ensure safe operation even during failures. The dual-channel architecture shown uses primary and backup sensors feeding into a voter system, with a safety monitor overseeing the entire process to enable graceful degradation when faults occur.
Testing methodologies for autonomous electric vehicles follow a comprehensive multi-layered approach. Unit testing validates individual components, integration testing verifies component interactions, and system validation confirms overall functionality. Hardware-in-the-Loop and Software-in-the-Loop testing simulate real-world conditions safely. Fault injection testing deliberately introduces failures to validate safety mechanisms. Testing coverage requirements increase with ASIL levels, from 60% for ASIL A to 100% for ASIL D, ensuring thorough validation of safety-critical functions.