Link Actuator Control Device for Wide Operating Range
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Solution Overview
Problem
Existing link actuators with parallel link mechanisms face challenges in achieving a wide operating range while maintaining rigidity, leading to limited weight capacity and increased torque requirements, which results in positioning inaccuracies and assembly issues.
Innovation Solution
A control device for a link actuator with three or more link mechanisms in a trinodal crank chain, utilizing a position change control unit and relay position setting unit to synchronize arm movements and reduce excessive load, allowing for high-speed movement without significant calculation delays or memory storage issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the link length is increased to expand the operating range of the travelling plate, then the operating range is improved, but the rigidity of the mechanism deteriorates
Solution Approach 1:
The mechanism is divided into multiple links (first link, second link, third link, fourth link) connected in series, allowing the operating range to be expanded through the coordinated movement of segmented components rather than increasing a single link length
Solution Approach 2:
The mechanism transitions from planar movement to three-dimensional movement by introducing the travelling plate that moves in both horizontal and vertical directions, expanding the operating range without proportionally increasing link lengths
2Adaptability or versatility
If the link length is increased to expand the operating range, then the operating range is improved, but the weight capacity of the travelling plate deteriorates
Solution Approach 1:
The load-bearing function is distributed across multiple links and support points rather than relying on a single long link, maintaining weight capacity while expanding operating range through coordinated movement of segmented components
Solution Approach 2:
The mechanism incorporates curved or angled link arrangements that provide mechanical advantage and distribute forces more effectively, maintaining weight capacity while enabling expanded operating range
3Adaptability or versatility
If three or more link mechanisms are used to provide precise and wide operating range, then the operating range is improved, but the device complexity increases
Solution Approach 1:
Multiple link mechanisms perform coordinated functions simultaneously - the first and second links provide horizontal movement, the third and fourth links provide vertical movement, and all links work together to maintain structural stability, making the complex mechanism efficient rather than redundant
4Adaptability or versatility
If the position change amount is large, then the positioning range is improved, but the torque requirements increase causing positioning inaccuracies
Solution Approach 1:
Large position changes are achieved through the coordinated contribution of multiple links rather than requiring high torque from a single actuator, distributing the force requirements across the mechanism
Solution Approach 2:
The mechanism uses three-dimensional link arrangements and spatial force distribution to reduce torque requirements while achieving large positioning ranges, utilizing vertical and horizontal components of force
Data Source
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AI summary
A control device is provided which is operable to change the position of a distal end side link hub by driving each of arms, which are proximal end side links of a plurality of link mechanisms by means of an actuator. When in a series of operations, the position change of the distal end side link hub is mad by an angle greater than a predetermined angle, a relay position setting unit is provided for setting a relay point between a starting point and a terminating point of each of the arms so that the interference of the three axis arms may be relieved. A position change control unit performs a position control so as to pass simultaneously through the relay point so set.