Cable-Constrained Planar Positioning for Precise Scalable Motion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current positioning systems, such as Cartesian robots and cable robots, face challenges in scalability and precision due to the need for heavy bearing structures and complex control systems, which hinder large-scale applications and precise control of moving members.
Innovation Solution
A planar positioning system using flexible constraint members, specifically cables, to constrain the degrees of freedom of a moving output member, with a guide mechanism and restraint mechanisms that include cable uptake and release devices and variable-radius spools to maintain precise positioning and scalability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If heavy bearing structures are used to constrain the output member in Cartesian robots, then positioning precision is improved, but system weight and complexity increase
Solution Approach 1:
The patent extracts the heavy bearing structure from the moving components and relocates it to the fixed frame. The output member is constrained by cables anchored to the frame rather than by moving bearings, eliminating the need for heavy moving bearing structures while maintaining positioning precision.
Solution Approach 2:
The patent replaces the traditional mechanical bearing system with a cable-based constraint system. Instead of using physical bearings to constrain the output member, the system uses tensioned cables to achieve the same constraining effect, significantly reducing moving mass and system complexity.
2Weight of moving object
If cable robots eliminate heavy moving structures, then system weight is reduced, but control precision deteriorates due to nonlinear equations
Solution Approach 1:
The patent segments the constraint system into independent cable pairs, each pair responsible for constraining specific degrees of freedom. This segmentation allows for simpler control of individual cable pairs while maintaining overall positioning precision, avoiding the need to solve complex coupled nonlinear equations.
Solution Approach 2:
The patent changes the control parameters from solving nonlinear position equations to directly controlling cable lengths and tensions. By parameterizing the system in terms of cable lengths rather than Cartesian coordinates, the control becomes more straightforward while maintaining precision.
3Adaptability or versatility
If flexible constraint members are used to constrain degrees of freedom, then system scalability is improved, but additional degrees of freedom need restraint
Solution Approach 1:
The patent designs the cable constraint mechanism to serve multiple functions simultaneously: it constrains translational degrees of freedom while also providing restraint against rotational degrees of freedom. This multi-functionality allows the same basic cable-pulley structure to scale to different applications without requiring fundamentally different mechanisms.
Solution Approach 2:
The patent employs dynamic cable tension control to restrain additional degrees of freedom. By actively adjusting cable tensions in real-time, the system can adapt to different operational requirements and constrain various degrees of freedom as needed, providing scalability without fixed structural constraints.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A system and method for a planar positioning system for an output member, the system having a pair of x-coordinate linear carriages and a pair of y-coordinate linear carriages. The system has a guide mechanism for the pair of x-coordinate linear carriages and the pair of y-coordinate linear carriages. The system has a plurality of movement and constraining cables extending from the pair of x-coordinate linear carriages and the pair of y-coordinate linear carriages to the output member for driving the output, wherein the pair of x-coordinate linear carriages and the output member move in sync in the x-direction and the pair of y-coordinate linear carriages and the output member move in sync in the y-direction. A restraint mechanism restrains the output member in an additional degree of freedom besides the x- and y-directions.