Cable-Driven Robot Arm Joint With Multi-Turn Pulleys
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current robot arm technologies face challenges in achieving the necessary flexibility and rigidity to perform minimally invasive surgeries, such as single port surgery and Natural Orifice Translumenal Endoscopic Surgery (NOTES), where a robot arm needs to be firmly fixed in a curved internal environment with minimal incision or no incision, requiring a balance of flexibility and rigidity.
Innovation Solution
A robot arm design featuring a joint unit formed by stacking link modules with a driving system that includes cables and multi-turn pulleys, allowing the joint unit to pivot along multiple axes, with cables forming closed loops and pulleys changing the cable path to transmit driving force effectively, ensuring secure coupling and amplified rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a robot arm is designed with high rigidity to be firmly fixed in curved internal environments, then stability is improved, but the robot arm loses flexibility and cannot navigate curved paths
Solution Approach 1:
The robot arm is divided into multiple link modules that can be stacked in series. Each link module contains a joint unit with driving devices, allowing independent control of each segment. This segmentation enables the robot arm to achieve both rigidity within each module and flexibility through the combination of multiple modules, resolving the contradiction between stability and adaptability in curved internal environments
Solution Approach 2:
The robot arm employs a dynamic structure where link modules can be selectively activated and deactivated based on the required task. The driving devices include motors that can dynamically adjust the rigidity and flexibility of each joint, allowing the robot arm to transition between rigid fixed positions and flexible curved paths as needed
2Adaptability or versatility
If a robot arm uses a complex driving system with multiple cables and pulleys to achieve multi-axis pivoting, then adaptability is improved, but device complexity increases
Solution Approach 1:
The driving system uses a nested cable-pulley arrangement where cables are routed through multiple pulleys within each link module. The cables form closed loops that pass through pulleys in a nested sequence, allowing compact integration of multiple driving functions within each joint unit while achieving multi-axis pivoting capability
Solution Approach 2:
The cable-driven mechanism serves multiple functions simultaneously: it provides driving force for pivoting, transmits motion across multiple axes, and maintains structural support. The same cable-pulley system that enables multi-axis movement also contributes to the overall structural integrity, reducing the need for separate support components and simplifying the overall device
3Force
If cables pass through link modules multiple times with multi-turn pulleys to amplify driving force, then force efficiency is improved, but the cable path becomes more complex
Solution Approach 1:
Multi-turn pulleys serve as intermediary elements between the cable and the joint unit. These pulleys are configured to change the cable path multiple times, effectively amplifying the driving force transmitted to the joint unit. The pulleys act as force multipliers while maintaining a relatively organized cable routing pattern that passes through defined paths in each link module
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 enables a robot arm to be driven with minimal force while maintaining rigidity, allowing precise movement along multiple axes, enhancing its ability to navigate curved internal environments with high precision and stability.
Implementation Method 1
The driving unit may be configured to pull or push the cable such that the joint unit pivots
Implementation Method 2
The plurality of multi-turn pulleys may be configured to change a path of the cable when the cable passes therethrough
Data Source
AI summary
A robot arm capable of being driven with a small force while having an enhanced rigidity includes a joint unit formed by stacking a plurality of link modules up against each other, and at least one driving device allowing the joint unit to pivot along at least one axis, wherein the driving device includes a cable disposed to pass through the plurality of link modules a plurality of times, a plurality of multi-turn pulleys configured to change a path of the cable when the cable passes therethrough, such that the cable passes through the plurality of link modules, and a driving unit configured to pull or push the cable such that the joint unit pivots.