Robotic Arm Central Channel Shape Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robotic arms with articulated links face challenges in measuring shape accurately, especially for small diameter arms with limited peripheral space, and require complex construction methods that complicate the integration of control and service cables.
Innovation Solution
An elongate robotic arm with a central channel and a flexible, resilient stiffening member that includes a sensor, such as an optical fibre, to measure the arm's shape, allowing for precise mechanical engagement of links and easier cable threading, with the stiffening member fixed at optimal points to ensure accurate shape measurement and prevent buckling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors are mounted around the periphery of links to measure arm shape, then shape measurement is possible, but the device complexity increases and peripheral space is consumed
Solution Approach 1:
The sensor is integrated within the stiffening member itself, merging the shape measurement function with the structural stiffening element. This eliminates the need for separate peripheral sensors and reduces overall device complexity while maintaining measurement capability.
Solution Approach 2:
The stiffening member serves multiple functions: providing torsional stiffness to the arm and housing the shape sensor. This multi-functionality reduces the number of separate components needed and simplifies the overall device architecture.
2Ease of manufacture
If control cables are threaded through the complete arm after construction, then cable routing is achieved, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The control cables are threaded through the links during the assembly process itself, rather than after the arm is fully constructed. This preliminary action integrates cable routing with the assembly operation, reducing both manufacturing complexity and time.
3Volume of moving object
If the arm diameter is reduced for compactness, then the arm becomes more compact, but peripheral space for sensors and cables is reduced
Solution Approach 1:
The sensor is placed within the stiffening member's internal structure rather than on the peripheral surface. This merging of functions allows the arm to maintain a compact diameter while still accommodating the sensor and other components within the internal volume.
4Manufacturing precision
If links are engaged mechanically precisely, then assembly precision is improved, but the construction process becomes more complex
Solution Approach 1:
The links are designed to self-align and engage with each other through their geometric configuration and the stiffening member's structure. This self-service mechanism achieves precise engagement without requiring complex external alignment tools or procedures.
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 solution simplifies shape measurement, enhances torsional stiffness, and allows for precise construction and efficient cable management, improving the arm's bending and torsional stiffness while maintaining accurate shape detection.
Implementation Method 1
The sensor may be an elongate sensor member such as an optical fibre, a plurality of optical fibres, or a single fibre with multiple cores extruded within it. The fibre may have Bragg gratings etched within each core for different strain sensing.
Implementation Method 2
The fibre may have Bragg gratings etched within each core for different strain sensing.
Implementation Method 3
The stiffening member is preferably flexible and resilient.
Data Source
AI summary
An elongate robotic arm comprising articulated segments and a channel that extends along the longitudinal axis of the arm and contains a stiffening member which includes a sensor for measuring the shape of the arm. Using the central channel for this purpose improves the ease and accuracy of shape measurement.