Material-Independent Mass Flow Sensor With Three-Axis Force Sensing
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Solution Overview
Problem
Traditional mass flow measurement methods in grain harvesting combines are inaccurate and require frequent recalibration due to variations in grain properties, leading to unreliable yield estimation.
Innovation Solution
A material independent mass flow sensor using a three-measurement transducer to detect bend force, stretch force, and torque, allowing for precise mass flow calculations independent of grain type by eliminating friction and other variable dependencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional impact plate methods are used for mass flow measurement, then the device structure is simple, but measurement precision deteriorates due to dependency on grain type, moisture content, and other variables requiring frequent recalibration
Solution Approach 1:
The measurement system is segmented into three independent force component measurements (Fx, Fy, Fz) taken at multiple locations along the grain flow path. Each component is measured separately by dedicated force sensors, allowing independent analysis and calculation of mass flow parameters without cross-interference from grain property variations
Solution Approach 2:
A curved guide surface is introduced as an intermediary element between the grain flow and the force sensors. This guide surface converts the complex grain impact forces into standardized force components that can be consistently measured, eliminating the need for direct grain-sensor contact and reducing sensitivity to grain property variations
2Reliability
If unidirectional force measuring devices are used to detect impact force, then the device structure is simple, but reliability deteriorates because grain flow variations require frequent verification and recalibration
Solution Approach 1:
Different force sensors are positioned at specific locations along the grain flow path where they measure distinct force components (Fx, Fy, Fz). Each sensor is optimally positioned to capture a specific aspect of the grain-surface interaction, ensuring that local measurements are insensitive to variations in grain properties while collectively providing comprehensive mass flow information
Solution Approach 2:
The measurement system transitions from unidirectional force detection to three-dimensional force component measurement. By measuring forces in multiple spatial dimensions (Fx, Fy, Fz) and combining these measurements, the system achieves reliability under varying grain conditions without requiring complex recalibration procedures
3Ease of operation
If lookup tables and piecewise non-linear curves are used for force to mass flow conversion, then measurement precision can be maintained, but ease of operation deteriorates due to laborious calibration requirements throughout the harvesting season
Solution Approach 1:
The complex mechanical calibration system involving lookup tables and piecewise non-linear curves is replaced with a direct mathematical calculation system. The three force component measurements (Fx, Fy, Fz) are processed through analytical equations that directly yield mass flow parameters, eliminating the need for empirical calibration tables and simplifying operation while maintaining precision
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
Provides accurate and consistent mass flow measurements by accounting for friction and other variables, reducing the need for frequent recalibration and improving yield estimation accuracy.
Implementation Method 1
Changing friction coefficients mu between the bulk material and the surface will affect the flow pattern therealong
Implementation Method 2
grain is directed to move along the curved plate and a sensor detects forces (e.g., impact force and/or centripetal force) caused by the grain impacting and moving along the guide curve
Implementation Method 3
Impact of a portion of the grain generates a load-proportional electrical signal in the force measuring device
Data Source
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AI summary
A material independent mass flow sensor is used to generate signals that can be used to calculate mass flow of grain harvested by a combine. A method for determining a mass of material includes the steps of receiving data from a three-measurement transducer and determining an angular center of mass location of an object based on the data from the three-measurement transducer. A coefficient of friction of the object is determined. A velocity of the object is determined. A mass of the object is determined. The mass of the object can be determined based on the angular center of mass location of the object, the coefficient of friction of the object, and the velocity of the object.