In-Vehicle Sensor Calibration Split for Replacement Precision

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Solution Overview

Problem

In-vehicle sensor systems face precision issues when the surrounding sensor is replaced, as existing calibration methods assume no change in mounting errors, leading to decreased accuracy of detection data due to variations in the position and posture of the detector and casing relative to the vehicle body.

Innovation Solution

The system employs a second storage to store data representing the deviation of the casing and detector's actual position and posture, allowing for direct correction of detection data without recalculating mounting errors, maintaining data precision before and after sensor replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the surrounding sensor is replaced using the related-art apparatus, then the sensor can be replaced without recalibration, but the precision of detection data decreases due to mounting errors

Engineering Contradiction:
Improvesensor replacementVSAvoiddetection data precision
Core Design Contradiction:
Ease of repairVSMeasurement precision

Solution Approach 1:

The calibration parameters are segmented into two distinct components: (1) detector-to-casing mounting error parameters stored in the sensor unit's first storage, and (2) casing-to-vehicle-body mounting error parameters stored in the vehicle's second storage. This segmentation allows the sensor to be replaced without recalibration while maintaining precision, as the vehicle-specific mounting error data remains in the second storage and can be combined with the new sensor's detector-to-casing calibration data.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second storage in the vehicle acts as an intermediary that stores the casing-to-vehicle-body mounting error parameters independently of the specific sensor unit. This intermediary storage enables the separation of sensor-specific calibration from vehicle-specific mounting calibration, allowing sensor replacement without loss of overall system precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If sensor calibration is performed at the vehicle production factory, then the detection data precision is maintained, but the complexity of the production process increases

Engineering Contradiction:
Improvedetection data precisionVSAvoidproduction process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration process is segmented into two independent calibration operations: (1) detector-to-casing calibration performed at the sensor production factory with results stored in the first storage, and (2) casing-to-vehicle-body calibration performed at the vehicle production factory with results stored in the second storage. This segmentation reduces the complexity of each individual calibration process while maintaining overall detection precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detector-to-casing calibration is performed in advance at the sensor production factory before the sensor is installed in the vehicle. This preliminary calibration stores the detector-specific mounting error parameters in the first storage, simplifying the vehicle production process as only the casing-to-vehicle-body calibration needs to be performed at the vehicle factory.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If the position and posture of the detector differ from the normal position and posture, then the driving assistance apparatus cannot accurately recognize the situation, but recalibration is required which reduces productivity

Engineering Contradiction:
Improvesituation recognition accuracyVSAvoidsensor replacement efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The calibration parameters are segmented into detector-to-casing parameters (first storage) and casing-to-vehicle-body parameters (second storage). This segmentation allows the system to maintain accurate situation recognition after sensor replacement without requiring time-consuming recalibration, as the vehicle-specific mounting error data remains in the second storage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The calibration system creates a copy of the necessary calibration data structure, with detector-to-casing calibration parameters stored in the sensor unit and casing-to-vehicle-body parameters stored in the vehicle. This copying approach allows the new sensor to inherit the vehicle-specific mounting calibration without requiring complete recalibration, thereby maintaining productivity.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4047919B1In-vehicle sensor system, and data generation method for in-vehicle sensor system
Publication Date: 2024.07.10 TOYOTA JIDOSHA KK
  • EP4047919B1 patent drawingFigure 1
  • EP4047919B1 patent drawingFigure 2A~2B
  • EP4047919B1 patent drawingFigure 3

AI summary

Provided is an in-vehicle sensor system capable of maintaining an equivalent level of precision before and after replacement of a surrounding sensor. An in-vehicle sensor system (1) includes: a surrounding sensor including: a casing (11) removably mounted to a vehicle body; a detector (12) supported by the casing (11) and configured to output detection data; and a first storage storing first data corresponding to a deviation of actual position and posture of the detector (12) with respect to the casing (11) from predetermined normal design position and posture; a second storage (21) provided separately from the surrounding sensor and fixed to the vehicle body, and configured to store second data corresponding to a deviation of actual position and posture of the casing (11) with respect to the vehicle body from predetermined normal design position and posture; and a corrector (13) configured to correct the detection data output from the detector (12) based on the first data and the second data.