Vending Machine Product Detection Using Optical Encoder and Capacitive Sensor
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Solution Overview
Problem
Vending machines often fail to reliably detect the transfer of a selected product into the delivery device, leading to consumer frustration and incorrect refund or re-attempts, as existing sensors may not accurately determine product presence at the initial stage of the vending operation.
Innovation Solution
A product detection system that includes an optical encoder associated with a motor to detect unexpected movement upon product transfer and a capacitive-type sensor to confirm product presence in the delivery device, ensuring accurate detection before completing the vending cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical beam sensor is positioned in the transport carrier to detect product transfer, then the detection capability is improved, but the system may still fail to reliably detect product presence at the initial stage
Solution Approach 1:
The patent positions the optical beam sensor to detect product transfer at the very beginning of the vending cycle, before the product fully enters the transport carrier. This preliminary detection allows the system to identify product presence early in the transfer process, preventing false negatives where products that partially entered the carrier were not detected.
Solution Approach 2:
The patent introduces an intermediary detection mechanism by placing the optical beam sensor in a strategic position between the product queue and the transport carrier. This intermediary position allows detection of the product during its transition state, providing more reliable detection than waiting for complete carrier insertion.
2Measurement precision
If the vending machine waits until near completion of the vending cycle to determine product delivery, then the detection accuracy is improved, but the consumer experience deteriorates due to frustration and delays
Solution Approach 1:
The optical beam sensor provides preliminary detection of product transfer early in the vending cycle, allowing the system to confirm product delivery before the cycle completes. This early confirmation eliminates the need to wait until the end of the cycle, reducing consumer waiting time and frustration while maintaining accurate detection.
3Device complexity
If the vending machine uses a single sensor to detect product transfer, then the device complexity is reduced, but the detection reliability deteriorates when products do not enter the cup properly
Solution Approach 1:
The patent segments the detection function into multiple independent sensor positions within the transport carrier system. By using multiple sensors at different locations, the system can detect product transfer through multiple possible pathways, ensuring reliable detection even if the product takes an unexpected route or enters the carrier at an unusual angle.
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
The system reliably detects the presence of a product in the delivery device, preventing incorrect refunds and re-attempts, and ensuring a smooth vending operation by confirming product receipt before proceeding.
Implementation Method 1
A sensor, such as an optical beam, is positioned in the transport carrier. When the selected product is transferred into the transport carrier, the beam is interrupted or broken.
Implementation Method 2
a capacitive-type sensor positioned in the delivery device. The capacitive-type sensor also signals the controller that the product is resting in the product delivery device.
Implementation Method 3
A controller activates the product transport system which drives a motor that shifts a product delivery device to a position adjacent one of the plurality of product queues.
Data Source
AI summary
A vending machine includes a product detection system for signaling a vending controller that a selected product has released from a product support shelf. The vending machine includes a product delivery device that, upon initiation of a vending operation, transports the selected product from the product support shelf towards a delivery area. Upon initiation of a vending operation, a motor moves a product delivery device to a position adjacent the selected product. A dispensing mechanism then releases the selected product which falls into the delivery device, imparting a downward force which is sensed at the motor. A sensor detects the downward force and signals the vending controller that the product has been received by the product delivery device. At this point, the vending controller continues with the vending operation.