IMU Self-Test Using Vehicle Mechanical Stimulus Events

Solution Overview

Problem

Inertial measurement units (IMUs) in vehicles lack effective self-test capabilities to detect faults and ensure proper mounting and orientation, which is crucial for accurate navigation, especially in GPS-denied environments.

Innovation Solution

A self-test system and method that utilizes external mechanical stimulation events, such as door openings or engine starts, to validate IMU data and determine mounting integrity and orientation, with a control circuit analyzing IMU data to confirm validity and detect potential faults.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the IMU is securely mounted within the vehicle, then the IMU data accuracy is improved, but the ability to detect faulty IMU mounting and orientation is worsened

Engineering Contradiction:

ImproveIMU data accuracyVSAvoidfault detection capability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system uses the IMU's own data collection capability to perform self-diagnosis. The control circuit analyzes IMU data to detect mounting faults and orientation errors without requiring external testing equipment, allowing the system to service itself while maintaining normal operation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system performs preliminary validation of IMU mounting and orientation by analyzing data during normal vehicle operation before critical failures occur. The control circuit continuously monitors IMU data for anomalies that indicate mounting issues, enabling early detection and correction.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If additional hardware is added for IMU self-test, then the fault detection capability is improved, but the device complexity is worsened

Engineering Contradiction:

Improveself-test capabilityVSAvoidhardware requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control circuit serves multiple functions: it processes normal IMU data for navigation and simultaneously performs fault detection analysis. The existing IMU hardware is used for both operational sensing and self-diagnosis, eliminating the need for separate testing hardware.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the IMU's own data collection capability to perform self-diagnosis. The control circuit analyzes IMU data to detect mounting faults and orientation errors without requiring external testing equipment, allowing the system to service itself while maintaining normal operation.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If external mechanical stimulation is used for testing, then the mounting integrity verification is improved, but the test system complexity is worsened

Engineering Contradiction:

Improvemounting verification accuracyVSAvoidtest system structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system converts normal vehicle operational vibrations and movements, which could be considered noise or interference, into useful test stimuli. These everyday mechanical stimulations are sufficient to validate IMU mounting integrity without requiring dedicated test equipment.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The control circuit serves multiple functions: it processes normal IMU data for navigation and simultaneously performs fault detection analysis. The existing IMU hardware is used for both operational sensing and self-diagnosis, eliminating the need for separate testing hardware.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables reliable verification of IMU mounting and orientation without additional hardware, ensuring accurate navigation and fault detection, thereby enhancing the reliability of IMU data in various applications, including self-driving vehicles.

Implementation Method 1

inertial measurement units that includes one or more accelerometers and/or gyroscopes for determining the speed, orientation, and/or position of the vehicle

Methodology Applied

Scientific EffectAccelerometer: Accelerometer

Data Source

PatentUS11892319B2System and method for self-test of inertial measurement unit (IMU)

Publication Date: 2024.02.06 APTIV TECHNOLOGIES AG

AI summary

An inertial measurement unit (IMU) self-test system includes an IMU and a control circuit. The control circuit is configured to receive IMU data collected by the IMU and inputs from systems external to the IMU indicative of mechanical stimulus, wherein the control circuit utilizes IMU data collected in response to the mechanical stimulus to determine IMU validity.