Dome Pressure Sensor for Object Hardness Measurement
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Solution Overview
Problem
Existing robot grippers struggle to accurately measure the hardness of objects, leading to improper gripping forces that can cause deformation or dropping of soft objects.
Innovation Solution
A pressure sensor with a dome-shaped elastic member and dual pressure-sensitive elements that measure the ratio of detection signals to determine object hardness, enabling controlled gripping forces based on the hardness of the object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a load sensor with multiple electrodes is used to sense gripping load, then gripping force control is improved, but the ability to measure object hardness deteriorates
Solution Approach 1:
The sensor surface is divided into multiple pressure-sensitive elements arranged in a matrix pattern, with each element independently measuring pressure at its location. This segmentation allows the system to capture pressure distribution across the contact surface, enabling both gripping force control and object hardness measurement by analyzing the spatial pattern of pressure readings.
Solution Approach 2:
The invention transitions from measuring only the magnitude of gripping force to measuring the two-dimensional pressure distribution across the contact surface. By adding spatial dimension information through the matrix arrangement of pressure-sensitive elements, the system can derive object hardness characteristics from the pressure map, resolving the contradiction between force control and hardness measurement capabilities.
2Reliability
If gripping force is increased to prevent dropping of soft objects, then object retention is improved, but object deformation increases
Solution Approach 1:
The system continuously monitors pressure distribution through the matrix of pressure-sensitive elements and uses this feedback to dynamically adjust gripping force. By analyzing the pressure map in real-time, the control system can detect signs of object deformation and reduce gripping force accordingly, or detect slipping tendencies and increase force to prevent dropping, thus resolving the contradiction between retention and deformation prevention.
Solution Approach 2:
The pressure-sensitive element matrix enables localized measurement of pressure at different contact points. This local quality information allows the system to identify areas of excessive pressure that may cause deformation and adjust the gripping strategy to distribute force more evenly, while maintaining sufficient overall gripping force to prevent object dropping.
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 pressure sensor allows for precise adjustment of gripping forces, preventing deformation and dropping of objects by accurately measuring and responding to their hardness.
Implementation Method 1
a first pressure-sensitive element placed in a position between the mounting surface and the elastic member and corresponding to a vertex of the convex curved surface and outputting a first detection signal by sensing pressure
Data Source
AI summary
A pressure sensor includes a base having a mounting surface, an elastic member mounted on the mounting surface and forming a dome shape including a convex curved surface, a first pressure-sensitive element placed in a position between the mounting surface and the elastic member and corresponding to a vertex of the convex curved surface and outputting a first detection signal by sensing pressure, a second pressure-sensitive element placed in a position between the mounting surface and the elastic member and corresponding to a peripheral portion of the convex curved surface and outputting a second detection signal by sensing pressure, and a calculator performing a calculation on the first detection signal and the second detection signal, wherein the calculator measures hardness of an object based on a ratio R1-1/2 between the first detection signal and the second detection signal when the object is pressed against the elastic member with a first load.