Load Cell Eccentric Load Compensation via Link Filter
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Solution Overview
Problem
Existing load cells provide measurements with substantial errors when eccentric loads are applied due to nonlinearities in sensor activation, as the sensors are activated unsymmetrically, leading to inaccuracies in load measurement.
Innovation Solution
A load cell design that incorporates a link with pivots between the elastic body and the sensor, which filters out non-parallel movements of the membrane, ensuring that only deformations in line with the applied force are measured, thereby absorbing and canceling out eccentric load-induced deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the sensor is directly connected to the membrane, then the measurement structure is simple, but measurement errors occur when eccentric loads are applied due to unsymmetrical sensor activation
Solution Approach 1:
A connector is introduced as an intermediary element between the membrane and the sensor. This connector transmits only the force component parallel to the membrane's normal direction, filtering out eccentric load components. The connector acts as a mechanical mediator that selectively transmits force components, thereby eliminating measurement errors caused by unsymmetrical activation while maintaining a relatively simple overall structure.
2Speed
If the sensor directly measures membrane deformation, then the measurement response is direct, but nonlinearities in sensor activation cause substantial measurement errors under eccentric loads
Solution Approach 1:
The connector serves as a mechanical intermediary that transmits force from the membrane to the sensor. It filters the force transmission to only pass the component parallel to the membrane's normal direction, thereby eliminating nonlinearities caused by eccentric loads while maintaining direct measurement response through the force transmission path.
Solution Approach 2:
The connector changes the parameter transmission by selectively transmitting only the force component parallel to the membrane's normal direction. This parameter filtering approach transforms the measurement input from a combination of multiple force components to a single purified force component, eliminating measurement errors while preserving direct response.
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 design effectively eliminates measurement errors caused by eccentric loads, providing accurate load measurements by isolating and canceling out non-parallel deformations, thus ensuring the load cell is independent of eccentrically applied forces.
Implementation Method 1
a flexible membrane that is adapted to yield upon application of a load to the membrane
Data Source
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AI summary
A load cell comprising an elastic body having a base, a flexible membrane that is adapted to yield upon application of a load to the membrane, a sensor for measuring the load applied to the membrane, at least one connector having a first end that is connected to the membrane and a second end that is connected to the sensor, where the connector is configured to transmit a mechanical force that is applied to the membrane to the sensor.