Vertical Sensor Array for Self-Checkout Product Length Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing self-checkout systems face challenges in accurately validating products of irregular or odd shapes due to inconsistencies in data provided by single pair rear sensors and vertical LED arrays, leading to confusion in determining complete transfer of products from the weighing conveyer to the transport conveyer.
Innovation Solution
Implementing a vertical sensor array along the weighing conveyer that measures product length and time of passage through the sensor array, allowing the system to dynamically enable scanner input and accurately determine product weight, even with multiple products present, without the need for a second arch at the end of the conveyer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pair of LEDs is used for the rear sensor, then the device complexity is reduced, but the measurement precision deteriorates due to inconsistent data for irregularly shaped products
Solution Approach 1:
The patent uses the front arch's vertical LED array configuration as a reference model and replicates its sensing capability at the rear position. Instead of using a simple single-pair LED sensor, the system copies the successful front arch design to the rear, ensuring both positions provide consistent, reliable data for product validation and transfer detection.
2Measurement precision
If a second arch is installed at the end of the weighing conveyer, then the measurement precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent merges the functions of product validation and transfer detection into a single rear sensor array. Instead of installing a separate second arch, the rear sensor array performs both the validation function (comparing product dimensions to reference data) and the transfer detection function (determining when the product has left the weighing conveyer), eliminating redundant hardware.
Solution Approach 2:
The rear sensor array is designed to perform multiple functions: it validates the product by comparing its dimensions to reference data, detects when the product has been transferred to the transport conveyer, and provides consistent data for irregularly shaped products. This multi-functional design eliminates the need for separate validation and transfer detection systems.
3Productivity
If the scanner remains enabled during product movement, then the productivity is improved, but the reliability deteriorates due to inaccurate weight measurements with multiple products on the conveyer
Solution Approach 1:
The system determines the transfer time of the current product before the next product arrives on the weighing conveyer. By using the rear sensor array to predict when the current product will leave, the system can prepare to disable the scanner at the appropriate moment, ensuring accurate weight measurements are taken before additional products are added to the conveyer.
Solution Approach 2:
The system continuously monitors the weigh cell output and compares it against expected weight values. When the weight deviates from the expected value (indicating multiple products are on the conveyer), the system provides feedback to disable the scanner, preventing inaccurate measurements from being recorded and maintaining measurement reliability.
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
This solution enables accurate validation and efficient transaction processing by predicting the correct time of product transfer and weight determination, optimizing the self-checkout system's operation and reducing costs by eliminating the need for additional sensors.
Implementation Method 1
measuring a length of time for the object to pass completely through the sensor array. Since the conveyer speed is known, the processor can determine the length of the object by multiplying the time measured by the speed of the conveyer
Implementation Method 2
acquiring weight data from the weighing conveyer that is associated with the object
Data Source
AI summary
A vertical sensor array is placed along a weighing conveyer in a self-checkout system. Successive products are scanned and then placed on the weighing conveyer. As a product traverses the sensor array, a firmware control sends a measured height of the product to processor software, and also indicates the time taken by the product to pass the array. From the time, conveyer speed, and distance from the array to the end of the weighing conveyer, the software determines the time when the product will be transferred from the weighing conveyer to a location adjacent to the weighing conveyer. Since this transfer time is variable, depending on the product and the particular orientation of the product when it is placed on the weighing conveyer, the software can dynamically enable the scanner input device for the associated system to accept the next following product or item. The software can accurately determine the correct weight of a product, even when multiple products are present on the conveyer simultaneously.