Strain-Sensing Shaft Input Circuit for High-Sensitivity Force Detection
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Solution Overview
Problem
Existing input devices require significant distortion of the strain generator to increase detection sensitivity, which compromises the durability of the strain generator.
Innovation Solution
An input device with a shaft portion, a plate-shaped deformation portion, and a detection circuit that includes multiple strain detection elements and fixed resistors, allowing for high-sensitivity force detection without increasing the strain on the strain generator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the strain generator is greatly distorted to increase detection sensitivity, then the output of the detection circuit increases, but the durability of the strain generator decreases
Solution Approach 1:
The patent divides the detection function into two independent measurement circuits: a first measurement circuit that detects forces in the X-axis direction and a second measurement circuit that detects forces in the Y-axis direction. Each circuit uses separate strain detection elements (first and second strain detection elements for X-axis, third and fourth strain detection elements for Y-axis), allowing independent optimization of each detection axis without requiring excessive distortion of a single strain generator structure.
Solution Approach 2:
The patent changes the electrical configuration parameters by introducing fixed resistors (first fixed resistor connected to supply voltage, second fixed resistor connected to ground) and arranging strain detection elements in specific bridge circuit configurations. This allows the detection circuit to achieve high sensitivity through electrical parameter optimization rather than mechanical distortion, thereby resolving the contradiction between detection sensitivity and strain generator durability.
2Measurement precision
If the strain generator is greatly distorted to increase output, then detection sensitivity improves, but the strain generator durability is reduced
Solution Approach 1:
The detection system is segmented into multiple independent measurement circuits, each handling specific detection tasks. The first measurement circuit with its dedicated strain detection elements handles X-axis detection, while the second measurement circuit handles Y-axis detection. This segmentation allows each circuit to operate within optimal strain ranges, preventing the need for excessive overall distortion that would compromise strain generator strength.
Solution Approach 2:
Fixed resistors are introduced as intermediary elements in the measurement circuits. The first fixed resistor connects to the supply voltage in the first measurement circuit, and the second fixed resistor connects to ground in the second measurement circuit. These intermediaries enable precise control of electrical parameters and signal conditioning, allowing high detection sensitivity to be achieved through circuit design rather than excessive mechanical strain on the strain generator.
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 device achieves high-sensitivity force detection in multiple directions with doubled sensitivity and dynamic range compared to prior art, without compromising the durability of the strain generator.
Implementation Method 1
a plurality of strain detection elements provided on the deformation portion
Implementation Method 2
a detection circuit, wherein the detection circuit includes a first measurement circuit including some of the plurality of strain detection elements and detecting a force in a direction orthogonal to the axial direction
Data Source
AI summary
An input device includes a shaft portion, a deformation portion, a plurality of strain detection elements, and a detection circuit, the detection circuit includes a first measurement circuit including some strain detection elements and detecting a force applied to the shaft portion in a direction orthogonal to the axial direction, a second measurement circuit including other some strain detection elements and detecting a force applied to the shaft portion in the direction, a first fixed resistor connected to a supply voltage of the first measurement circuit, and a second fixed resistor connected to a ground of the second measurement circuit, and the input device detects a force applied to the shaft portion in the axial direction based on a voltage between a connection point of the first measurement circuit and the first fixed resistor and a connection point of the second measurement circuit and the second fixed resistor.