Force Sensor With Segmented Elastic Body
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Solution Overview
Problem
Existing force sensors face a tradeoff between rigidity and sensitivity, with flexible sensors causing operational disturbances in integrated systems, and active sensors suffer from complexity and limited bandwidth.
Innovation Solution
A force sensor design featuring an elastic body with specific locations for strain gauges, including bridges and slits, allowing deformation in one direction while blocking others, enabling precise force measurement through strain gauge assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the elastic body is made very flexible to increase force sensitivity, then the force resolution is improved, but the sensor perturbs the operation of the measuring system
Solution Approach 1:
The elastic body is segmented into multiple functional zones: a first region with low stiffness for sensitive force measurement, a second region with intermediate stiffness, and a third region with high stiffness for system stability. This segmentation allows the sensor to simultaneously achieve high force resolution and operational stability by distributing different mechanical properties across different spatial locations.
Solution Approach 2:
Different regions of the elastic body are assigned different local mechanical properties (stiffness values). The first region has low stiffness optimized for force sensitivity, while the third region has high stiffness optimized for system stability. This local differentiation of mechanical properties resolves the contradiction between overall flexibility and operational stability.
2Measurement precision
If an active sensor with position sensor and actuator is used to achieve infinite apparent stiffness, then the force sensitivity is improved, but the device complexity increases
Solution Approach 1:
The elastic body structure itself provides the stiffness modulation function through its multi-region design. The gradient stiffness distribution enables the sensor to achieve high force sensitivity and operational stability passively, without requiring external position sensors or actuators. The structure serves its own measurement and stabilization functions.
Solution Approach 2:
The complex active control system (position sensor + actuator + controller) is replaced by a passive mechanical structure with gradient stiffness. The mechanical design inherently provides the desired force sensitivity and stability characteristics without requiring electronic feedback control, thereby eliminating the associated complexity.
3Measurement precision
If an active sensor with control loop is used to achieve infinite apparent stiffness, then the force sensitivity is improved, but the bandwidth of the control loop is limited
Solution Approach 1:
The elastic body's gradient stiffness structure provides instantaneous passive stiffness modulation without requiring dynamic control loops. The mechanical properties are built into the structure itself, enabling immediate response to force changes across the full bandwidth, eliminating the bandwidth limitations inherent in active control systems.
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 design achieves high sensitivity in force measurement with minimal interference from unwanted deformations, enhancing operational stability and precision.
Implementation Method 1
at least one strain gauge, wherein the elastic body is configured to deform essentially exclusively in at least a first specific location, wherein the first specific location hosts the strain gauge
Data Source
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AI summary
An elastic body is configured to deform essentially exclusively in at least a first specific location.