Robotic Whisker Profile Sensing via Base Torque
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Solution Overview
Problem
Existing robotic whisker technologies for sensing object profile shape are limited in their ability to continuously estimate contact points beyond initial contact, which restricts the acquisition of maximum profile shape information per whisker, especially in three-dimensional feature extraction.
Innovation Solution
A method involving a robotic whisker with a deflectable cantilever region that sweeps along an object's periphery, allowing continuous estimation of contact points by measuring moment at the whisker base, using simple algebraic expressions and two polynomials, and iteratively determining successive contact points, which can be implemented with small, inexpensive torque sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If whisker tapping method is used to estimate contact point location, then measurement precision is improved, but quantity of profile shape information obtained is limited
Solution Approach 1:
The patent implements continuous whisker sweeping motion along the object surface, maintaining contact throughout the measurement process. This continuous action allows the whisker to trace the entire profile shape, capturing multiple contact points sequentially rather than relying on a single tapping event, thereby maximizing information acquisition per whisker deployment
2Loss of information
If whisker sweeping is implemented to capture profile information, then quantity of profile shape information is improved, but device complexity increases
Solution Approach 1:
The patent extracts and utilizes only the moment (torque) measurement capability from the sensing system, eliminating the need for complex six-axis force/torque sensors. By focusing exclusively on moment measurement at the whisker base and combining it with geometric modeling, the system achieves profile shape extraction with simplified sensing hardware
Solution Approach 2:
The patent replaces complex mechanical sensing systems with a combination of simple moment measurement and computational geometry. Instead of using multiple sensors to directly measure position and orientation, the system uses a single moment sensor combined with elastic beam theory and geometric reconstruction algorithms to infer the complete profile shape
3Measurement precision
If complex sensing systems are used to achieve accurate contact point estimation, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent employs simple, inexpensive moment sensors (such as strain gauges) at the whisker base rather than expensive, complex force/torque sensors. The whisker itself is a simple elastic beam that can be easily manufactured or replaced. This approach prioritizes low-cost, easily manufactured components while achieving accurate measurements through intelligent algorithms
4Productivity
If iterative determination method is used to estimate successive contact points, then productivity is improved, but computational complexity increases
Solution Approach 1:
The patent pre-computes and stores the relationship between moment measurements and contact point positions based on elastic beam theory during system calibration. This preliminary action creates lookup tables or pre-computed models that can be quickly queried during actual measurement, avoiding the need for complex real-time iterative calculations while maintaining high accuracy
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 approach enables efficient and effective acquisition of object profile shape information over a single whisker, being robust to sensor noise and object friction, and suitable for implementation on arrays of robotic whiskers, with high accuracy in estimating contact points and object profiles.
Implementation Method 1
an elongated whisker element having a deflectable cantilever region... so that the cantilever bends as a result of sliding along an object periphery
Implementation Method 2
determining moment at a base region of the whisker element as a result of the bending
Data Source
AI summary
A method for sensing an object profile shape involves relatively sweeping (whisking or translating) in angular or translational increments an elongated whisker element having a deflectable cantilever region and an object so that the cantilever region bends as a result of sliding along an object periphery. The moment (torque) at a base region of the whisker element as a result of the bending is determined. The method then iteratively determines successive contact point locations on the object periphery based on small successive increments in angle or position of the whisker element and the sensed moment (torque).