Radar Error Indicator Pin for Functional Safety Monitoring

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Solution Overview

Problem

In mission-critical applications like Active Driver Assistance Systems, there is a need for rapid detection and management of functional irregularities in radar sensors to prevent unsafe system failures, particularly in compliance with stringent safety standards such as ISO 26262, where errors must be quickly identified and addressed to avoid dangerous braking actions.

Innovation Solution

An integrated circuit with an error monitor, error sensor, and dedicated error indicator pin is used to detect and report functional irregularities, featuring an inner safety monitor for local sensor data processing and an outer safety monitor for system-wide management, including power-down capabilities to ensure system safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated error indicator pins are provided for rapid error detection, then functional safety and reliability are improved, but device complexity increases due to additional pins and monitoring circuitry

Engineering Contradiction:
Improvefunctional safetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety monitoring function is segmented into dedicated error indicator pins that are separated from the main functional circuitry. Each pin independently indicates specific error conditions, allowing the monitoring function to be implemented without complicating the core radar processing architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Dedicated error indicator pins serve as intermediary elements between the internal error monitoring circuitry and the external control system. These pins provide a simple binary interface (error present/absent) that mediates the complex internal safety monitoring functions, reducing the interface complexity to the external system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If error conditions are quickly detected and reported, then system safety is improved, but response time and processing overhead increase

Engineering Contradiction:
Improveerror detection capabilityVSAvoidprocessing overhead
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Error monitoring is performed continuously and preliminarily throughout system operation. The dedicated error indicator pins are configured to immediately reflect error conditions as they occur, without requiring post-processing or additional analysis time, thus enabling rapid detection with minimal processing overhead.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The error indication mechanism replaces complex mechanical or software-based monitoring systems with direct electrical signal indicators. The dedicated pins provide immediate electrical signaling of error conditions, eliminating the need for software polling or complex detection algorithms that would increase processing time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If multiple monitoring functions are integrated into the radar system, then functional safety is improved, but the system becomes more difficult to reset and manage

Engineering Contradiction:
Improvefunctional safetyVSAvoidease of reset
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The dedicated error indicator pins serve multiple monitoring functions simultaneously. A single pin can indicate various types of errors (RF failures, baseband errors, digital processing failures) through different signal patterns or combinations, allowing one pin to perform multiple safety monitoring roles and simplifying the reset process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The error indicator pins provide immediate feedback about system safety status. This feedback mechanism allows the control system to automatically initiate reset procedures when errors are detected, and to verify when errors have been cleared, creating a self-managing safety system that reduces manual intervention complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2911027B1Functional safety monitor pin
Publication Date: 2020.12.09 NXP BV
  • EP2911027B1 patent drawingFigure 1~2
  • EP2911027B1 patent drawingFigure 3~4
  • EP2911027B1 patent drawingFigure 5~6

AI summary

A radar data processing system is disclosed. The system includes a microcontroller and a data receiver-transmitter integrated circuit coupled to the microcontroller. The data receiver-transmitter integrated circuit includes a sensor and a dedicated error indicator pin. The data receiver-transmitter integrated circuit includes an inner safety monitor and the microcontroller includes an outer safety monitor. The inner safety monitor configured to receive and collate sensor data from the plurality of sensors and send, through the dedicated error indicator pin, a function warning signal to the outer safety monitor when the sensor data from the sensor is indicative of a functional irregularity.