Coffee Grinder Bean Detection Using Speed Variation

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Solution Overview

Problem

Conventional coffee grinding devices face challenges in accurately detecting the presence or absence of coffee beans due to unreliable current draw measurements, which are influenced by voltage and design parameters, leading to imprecise threshold selection and increased hardware costs.

Innovation Solution

A method using Hall-effect sensors and a programmable micro-controller to monitor the grinding angular speed at different power levels, distinguishing between coffee bean-present and absent conditions by analyzing the variation in rotation period, without requiring additional hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If current draw sensors and control systems are used to detect coffee bean presence, then detection capability is provided, but device complexity and cost increase

Engineering Contradiction:

Improvecoffee bean presence detectionVSAvoidsensor and control system complexity

Core Design Contradiction:

Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The grinding device uses its own operational characteristics (grinding speed variations) to detect coffee bean presence without external sensors. The system self-monitors by comparing grinding speeds at different power levels, eliminating the need for separate detection hardware.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces electrical sensing systems with a mechanical measurement approach, using the grinding mechanism's own speed variations to indicate coffee bean presence. This substitutes complex electrical sensors with simple speed measurement capabilities already inherent in the motor control system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Difficulty of detecting and measuring

If current draw measurements are used to detect coffee beans, then detection is achieved, but measurement precision deteriorates due to voltage and parameter variations

Engineering Contradiction:

Improvecoffee bean presence detectionVSAvoiddetection accuracy

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from electrical current draw to mechanical grinding speed. By measuring speed variations at different power levels rather than current consumption, the system achieves more precise detection that is independent of voltage fluctuations and electrical parameter variations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from the grinding mechanism's own performance (speed measurements) to detect coffee bean presence. By continuously monitoring grinding speed and comparing it against reference values obtained at different power levels, the system achieves precise detection through self-feedback rather than external sensing.

Inventive Principle:

Principle #23Feedback

3Difficulty of detecting and measuring

If additional sensors and hardware are added for detection, then detection capability is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecoffee bean presence detectionVSAvoidmanufacturing cost

Core Design Contradiction:

Difficulty of detecting and measuringVSEase of manufacture

Solution Approach 1:

The patent makes the existing motor control system perform multiple functions: both grinding control and coffee bean presence detection. The same microcontroller and speed measurement capabilities used for motor control are also utilized for detection, eliminating the need for separate detection hardware and reducing manufacturing costs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The grinding device detects coffee bean presence using its own operational characteristics without requiring external detection systems. The motor control system monitors its own performance parameters (grinding speed) to provide detection functionality, eliminating the need for additional sensors and reducing manufacturing complexity.

Inventive Principle:

Principle #25Self-service

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 approach provides precise detection of coffee beans, reducing hardware needs and costs, while ensuring accurate operation and quality of the grinding process.

Implementation Method 1

A known coffee machine provides using a doser that is arranged downstream of a conventional coffee grinder... This type of coffee machine has a drawback in the doser overall size and in the extra-cost of both the doser and the detection and control electronic system.

Methodology Applied

Scientific EffectHall-effect: Hall Effect

Data Source

PatentUS8272586B2Method for detecting the amount of grains within a grinding device

Publication Date: 2012.09.25 VERSUNI HLDG BV

AI summary

A method for detecting an amount of grains within a container of a rotating grinding member is described, said method comprising the steps of: supplying (FORP1) a first driving torque to the rotating grinding member during a first interval (T1) of a grinding cycle (CM); —having (CTM1OO) a first value indicative of a period of rotation of said member at the first driving torque; supplying (RP2) the rotating grinding member, during a second interval (T2) of said cycle, with a second driving torque lower than the first driving torque; —measuring (CTM50) a second value indicative of the relative period of rotation of said member at the second driving torque, processing (CDTR, CNFR) the first and second values in order to generate information (ALR) indicative of the amount of grains being within the container.