Coffee Grinder Dosing Control Using Brewing Chamber Actuator Feedback
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Solution Overview
Problem
Existing automatic coffee machines struggle with accurately and consistently dosing ground coffee due to factors like variability in coffee beans, grind size, and component wear, leading to inconsistent beverage quality and potential machine operational issues.
Innovation Solution
An automatic coffee machine with an integrated grinder that adjusts grinding time based on feedback from the brewing assembly's electric actuator, using a control unit to compute the optimal grinding time for each brewing cycle, ensuring accurate and stable dosing of ground coffee.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed time or fixed number of revolutions is used for grinding, then the control system is simple, but the dosing precision of ground coffee is insufficient
Solution Approach 1:
The system measures the actual amount of ground coffee produced in each brewing cycle and uses this feedback to automatically adjust the grinding time or number of revolutions for the next cycle. This closed-loop control ensures precise dosing while adapting to variations in coffee beans, grind size, and component wear without requiring complex manual calibration.
Solution Approach 2:
The control unit automatically adjusts grinding parameters based on measured feedback from previous cycles, enabling the system to self-calibrate and maintain dosing precision without user intervention. This eliminates the need for manual grinding calibration while maintaining simple overall system architecture.
2Manufacturing precision
If fixed volume method is used, then direct control over ground coffee amount is achieved, but additional components and system complexity are required
Solution Approach 1:
The patent replaces mechanical volumetric measurement systems with an electronic measurement and control system that uses feedback from actual ground coffee amount to adjust grinding parameters. This substitution eliminates the need for complex mechanical volumetric chambers and adjustment mechanisms while achieving equivalent or superior dosing precision.
3Manufacturing precision
If feedback control based on electric current is used, then dosing accuracy improves, but the system requires additional sensors and control mechanisms
Solution Approach 1:
The control unit performs multiple functions: it controls the grinder motor, measures the amount of ground coffee produced, and adjusts grinding parameters for subsequent cycles. By integrating these functions into a single control unit that already exists in modern automatic coffee machines, the system achieves feedback control without adding significant complexity.
4Manufacturing precision
If manual calibration is performed, then initial dosing accuracy can be achieved, but the system cannot compensate for component wear and variability over time
Solution Approach 1:
The system continuously measures the actual ground coffee amount in each brewing cycle and uses this feedback to automatically adjust grinding parameters. This ongoing feedback mechanism compensates for component wear, coffee bean variability, and other changes over time, maintaining dosing accuracy without requiring repeated manual calibration.
Solution Approach 2:
The system performs automatic calibration adjustments before each brewing cycle based on feedback from previous cycles, ensuring that the grinding parameters are optimized in advance. This preliminary adjustment ensures consistent dosing accuracy throughout the machine's operation without requiring user intervention.
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 solution achieves precise and consistent dosing of ground coffee over time, improving the quality of the coffee beverage and preventing machine operational failures due to excessive or insufficient coffee dispensing.
Implementation Method 1
a feedback of an electric current absorbed by the electric actuator that closes the brewing assembly and compresses the ground coffee contained therein
Implementation Method 2
based on a feedback of an electric current absorbed by the electric actuator
Data Source
AI summary
An automatic coffee machine comprising a brewing assembly with a brewing chamber designed to contain a quantity of ground coffee and an electric actuator, which can be operated to cause the brewing chamber to be opened and closed; a grinder comprising an electric actuator operable to cause coffee beans to be ground and ground coffee to be produced; a hydraulic circuit to supply water to the brewing assembly to prepare a coffee beverage by brewing the ground coffee in the brewing chamber and comprising a water pump and a water flow meter to measure a quantity of water supplied by the water pump; a sensory system to sense and output an output indicative of different operating quantities of the automatic coffee machine and comprising an electric current absorbed by the electric actuator of the brewing assembly, a flow rate of the dispensed coffee beverage and an electric power absorbed by the water pump; a user interface to allow a consumer to request a beverage to be dispensed; and an electronic control unit designed to interface with the sensory system and the user interface to receive outputs thereof and with the brewing assembly, the grinder and the water pump to provide commands thereto. The electronic control unit is further designed to compute a coffee bean grinding time TN for which the grinder is to be operated in a coffee beverage preparation cycle to produce a quantity of ground coffee necessary to produce a selected coffee beverage, and to control the grinder accordingly. The electronic control unit is further designed to compute the coffee bean grinding time TN for which the grinder is to be operated in a coffee beverage preparation cycle based on the following quantities: a coffee bean grinding time TN-1 used in a previous coffee beverage preparation cycle; a difference ΔCurrentN-1 between an electric current C absorbed by the electric actuator of the brewing assembly during a closing of the brewing chamber in a previous coffee beverage preparation cycle in which the brewing chamber was loaded with ground coffee, the electric current CE absorbed by the electric actuator of the brewing assembly during the closing of the brewing chamber in a previous coffee beverage preparation cycle in which the brewing chamber was empty, and a maximum admissible limit CL for the electric current absorbed by the electric actuator of the brewing infuser during the closing of the brewing chamber; a difference ΔFlowN-1 between a measured flow rate F of the dispensed coffee beverage at the end of a previous coffee beverage preparation cycle and a target flow rate FA of the dispensed coffee beverage; and a difference ΔPumpN-1 between an electric power P absorbed by the water pump at the end of a previous coffee beverage preparation cycle and a target electric power PA absorbed by the water pump.