Load Cell Failure Detection via Linear Regression

Solution Overview

Problem

Load cells in inventory management systems can fail intermittently, leading to incorrect data and erroneous inventory tracking, as they may provide inconsistent or zero-load readings due to issues like loose connections or mechanical failures, which can result in incorrect determination of item interactions.

Innovation Solution

The system analyzes weight data from multiple load cells using techniques such as linear regression and Gaussian filtering to detect inconsistencies, allowing for the identification of faulty load cells and preventing erroneous data from being processed, thereby ensuring accurate inventory tracking by disregarding faulty data and initiating mitigation actions like deactivation or repair.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If load cells are used to monitor inventory weight, then inventory tracking capability is improved, but measurement reliability deteriorates due to intermittent failures and inconsistent readings

Engineering Contradiction:

Improveinventory tracking accuracyVSAvoidload cell reading consistency

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system continuously monitors load cell readings and compares them against expected weight ranges and historical data. When deviations are detected, the system generates feedback signals to trigger investigations, recalibrations, or replacements of faulty load cells, creating a closed-loop quality control mechanism that maintains measurement reliability despite component failures

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary validation checks on load cell readings before processing inventory data. By pre-screening readings for consistency, range compliance, and logical validity, the system prevents faulty measurements from entering the inventory tracking system, thereby maintaining accuracy even when load cells fail intermittently

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If multiple load cells are deployed across fixtures, then inventory monitoring coverage is improved, but system complexity increases due to multiple potential failure points

Engineering Contradiction:

Improvemonitoring coverage areaVSAvoidload cell system configuration

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The system implements a universal monitoring framework that handles multiple load cells through standardized procedures and algorithms. The same validation, detection, and response mechanisms apply regardless of the number or location of load cells, allowing the system to scale coverage across multiple fixtures without proportionally increasing operational complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system performs self-diagnosis by automatically detecting when a load cell fails or provides inconsistent readings. Through automated anomaly detection and comparison against expected patterns, the system identifies faulty components without requiring manual inspection of each load cell, thereby managing complexity through autonomous self-monitoring capabilities

Inventive Principle:

Principle #25Self-service

3Duration of action of stationary object

If load cell failures go undetected, then system operation continuity is maintained, but data accuracy deteriorates leading to erroneous inventory determination

Engineering Contradiction:

Improvesystem operation continuityVSAvoiditem interaction data accuracy

Core Design Contradiction:

Duration of action of stationary objectVSMeasurement precision

Solution Approach 1:

The system continuously monitors load cell readings and compares them against expected weight ranges and historical data. When deviations are detected, the system generates feedback signals to trigger investigations, recalibrations, or replacements of faulty load cells, creating a closed-loop quality control mechanism that maintains measurement reliability despite component failures

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary validation checks on load cell readings before processing inventory data. By pre-screening readings for consistency, range compliance, and logical validity, the system prevents faulty measurements from entering the inventory tracking system, thereby maintaining accuracy even when load cells fail intermittently

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11636424B1System and method to detect failures at a subset of load cells

Publication Date: 2023.04.25 AMAZON TECH INC

AI summary

Load cells are used in a fixture of a facility to acquire weight data. However, some of the load cells used in the fixture may fail. One way to test a subset of load cells is to compare data from a first subset of load cells to a second subset of load cells using a linear regression. For example, the linear regression may help determine predicted values for the first subset of load cells. Actual values from the first subset of load cells are then compared to the predicted values. If the differences between the actual values and predicted values for the first subset of load cells are greater than a threshold, a determination is made that the first subset of load cells has failed. Weight data from the second subset of load cells may then be used to determine hypotheses for describing interactions at the fixture.