Semi-Liquid Food Dispenser Control Using Stirring Speed Feedback

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Solution Overview

Problem

Existing control systems for viscous semi-liquid food dispensers, such as ice cream machines, face challenges in accurately maintaining product characteristics like overrun due to inadequate temperature control accuracy, indirect monitoring methods, and sensitivity to environmental factors, leading to inconsistent product quality.

Innovation Solution

A control method that utilizes real-time monitoring of both product temperature and stirring motor rotation speed to dynamically adjust refrigeration or heating, employing self-adaptive fuzzy control technology to maintain consistent viscosity, thereby minimizing environmental influences and ensuring accurate and reliable product characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If temperature-based control is used to maintain product characteristics, then the control system is simple to implement, but the control accuracy is insufficient and the response is lagging

Engineering Contradiction:
Improvecontrol system complexityVSAvoidtemperature control accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the traditional temperature-based control system with a rotation speed-based control system. Instead of using temperature sensors to indirectly monitor product characteristics, the system directly measures the rotation speed of the stirring motor, which correlates with product viscosity and overrun. This substitution eliminates the lagging response of temperature control while maintaining system simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces rotation speed as an intermediary parameter to control product characteristics. The rotation speed of the stirring motor serves as a direct indicator of product viscosity and overrun, allowing the control system to respond immediately to changes in product characteristics without the delay inherent in temperature-based monitoring.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If rotation speed sensor is used to detect load variation, then the control response is faster, but the measurement accuracy for determining softness and hardness is insufficient

Engineering Contradiction:
Improvecontrol response speedVSAvoidsoftness and hardness detection accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements a feedback control system that continuously monitors rotation speed and adjusts the stirring motor speed accordingly. The system compares the detected rotation speed with a preset reference value and makes real-time adjustments to maintain optimal product characteristics, thereby improving both response speed and measurement precision through closed-loop control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the control parameter from temperature or direct load measurement to rotation speed measurement. By monitoring the rotation speed of the stirring motor, the system obtains a more accurate and responsive indicator of product viscosity and overrun, enabling precise control of product characteristics.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If temperature is excessively increased in the refrigerated hopper, then the raw material becomes easier to stir, but partial melting occurs and overrun decreases

Engineering Contradiction:
Improvestirring easeVSAvoidoverrun consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces temperature-based control with rotation speed-based control to monitor and maintain product characteristics. By using rotation speed as the control parameter, the system can detect changes in product viscosity and adjust stirring intensity in real-time, preventing both excessive temperature increase and partial melting while maintaining consistent overrun.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If temperature is excessively decreased in the refrigerated hopper, then the raw material maintains overrun, but hardening occurs and stirring difficulty increases

Engineering Contradiction:
Improveoverrun maintenanceVSAvoidstirring difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements feedback control by continuously monitoring rotation speed and adjusting stirring motor speed accordingly. When product viscosity increases (indicated by rotation speed changes), the system automatically adjusts motor speed to maintain optimal stirring conditions, preventing hardening while preserving overrun through real-time parameter adjustment.

Inventive Principle:
Principle #23Feedback

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 control of viscosity, reducing oscillations in product characteristics and maintaining consistent quality by using direct viscosity indicators from rotation speed data, resulting in improved stability and reliability of the dispensed product.

Implementation Method 1

a refrigerating means configured to input cold energy into the food

Methodology Applied
Scientific EffectThermal energy transfer: Heat Exchanger

Implementation Method 2

a rotation speed sensor configured to detect a stirring speed

Methodology Applied
Scientific EffectRotational motion detection: Rotational Viscometer

Data Source

PatentEP3442351B1Viscous semi-liquid food dispenser and method and system for controlling food characteristics
Publication Date: 2023.11.08 SOCIETE DES PRODUITS NESTLE SA
  • EP3442351B1 patent drawingFigure 1
  • EP3442351B1 patent drawingFigure 2
  • EP3442351B1 patent drawingFigure 3

AI summary

A control method for a viscous semi-liquid frozen or hot food dispenser comprising a stirring means configured to stir the food, a motor (50) configured to drive the stirring means to rotate, a refrigerating means or heating means configured to input cold energy or heat energy into the food, a rotation speed sensor (80) configured to detect a stirring speed, and a temperature sensor (13) configured to detect the food temperature, the control method comprising the steps of: a) refrigerating or heating the food by the refrigerating means or heating means; b) comparing the food temperature detected by the temperature sensor (13) with a target preset value of the food temperature, and determining to continue the refrigeration or heating, or to stop the refrigeration or heating and to keep stopping for a preset time; c) intervening by corresponding adjustment of the target preset value when a data set collected from the rotation speed sensor (80) shows that change trend of the rotation speed meets predefined intervention conditions; and d) returning to step a) for the next cycle. The control method for a viscous semi-liquid food dispenser is capable of controlling viscosity of food accurately and reliably to maintain consistence of the characteristics of the dispensed product and minimize the influence from the environment as much as possible.