Cable-driven Manipulator Center of Mass Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cable-driven parallel manipulators face limitations in handling heavy and large objects due to constraints on cable tensions, which restrict the feasible wrench set, leading to restricted postures and motions of on-board mechanical manipulators, especially when dealing with off-centered or inclined loads.
Innovation Solution
The implementation of movable devices on the mobile platform, controlled by a computer module, to actively manage the overall center of mass (CoM) of the cable-driven parallel manipulator, ensuring it remains within a predetermined feasible region, thereby maintaining admissible cable tensions and expanding the manipulator's capabilities to handle increased wrenches and postures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cable tensions are constrained within admissible bounds, then the safety and proper operation of the manipulator are ensured, but the feasible wrench set is restricted, limiting the manipulator's ability to handle heavy and large objects
Solution Approach 1:
The patent introduces movable devices (counterweights, adjustable masses) on the mobile platform that can dynamically reposition to alter the center of mass location. This dynamic adjustment expands the feasible wrench set without compromising cable tension constraints, allowing the manipulator to handle varied loads and postures while maintaining safety
Solution Approach 2:
The patent changes the parameter of center of mass location by deploying movable devices to different positions on the platform. This parameter change directly expands the feasible wrench set, enabling the manipulator to handle heavy and large objects that would otherwise be outside the admissible cable tension bounds
2Force
If the feasible wrench set is expanded to handle heavy and large objects, then the manipulator's load handling capability is improved, but the cable tensions may exceed admissible bounds, compromising safety
Solution Approach 1:
The patent employs movable counterweights that can be positioned to generate opposing moments and forces. These counterweights offset the effects of heavy loads, allowing the manipulator to handle larger forces while keeping cable tensions within admissible bounds, thus maintaining safety
3Adaptability or versatility
If on-board mechanical manipulators are used to increase dexterity, then the operational capability is improved, but the cable tensions are disturbed, restricting the postures and motions available
Solution Approach 1:
The patent introduces movable devices as intermediary elements between the on-board manipulator and the cable system. These intermediaries actively adjust the center of mass to compensate for disturbances caused by manipulator operations, enabling fuller utilization of manipulator dexterity while maintaining cable tension within admissible bounds
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 allows for increased dexterity and load handling capabilities, enabling the use of high dexterity systems within large workspaces while keeping cable tensions within safe bounds, thereby expanding the operational capabilities of cable-driven parallel manipulators beyond conventional limits.
Implementation Method 1
a control module configured to generate an instruction to move the movable device for displacing an overall CoM of the cable-driven parallel manipulator
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention refers to a cable-driven parallel manipulator (10) comprising: - a support structure; - a cable system (30) mounted on the support structure; and - a mobile platform (20) connected to the cable system (30) whereto a load is attachable; - the cable system being controlled by a control unit to position and orientate the mobile platform (20) and/or to apply wrenches on the mobile platform (20); and further comprising: - at least one movable device (50, 51, 52, 50', 51', 52') mounted on the mobile platform (20); - a control module configured to generate an instruction to move the movable device (20) for displacing an overall center of mass of all of: the mobile platform, the at least one movable device and the load, such that, upon moving the movable device (20), the overall center of mass is within a predetermined region (101). The invention also refers to a method for stabilizing a load of a cable-driven parallel manipulator (10).