Parallel Kinematic Robot Structure for 6-DOF Motion Without Heavy Wrists
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Solution Overview
Problem
Current kinematic robots, whether serial or parallel, face limitations in speed and precision due to compounded errors in link elements and large mass, and require either a large footprint or heavy wrist elements to achieve full 6 DOF motion.
Innovation Solution
A parallel kinematic robot design featuring a body with at least two legs and two feet, each leg having a proximal and distal end region, with the proximal end coupled to the body at a rotational joint and the feet having two rotational degrees of freedom, allowing for independent translation and motion with six degrees of freedom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If serial robots are used to achieve 6 DOF motion with large work envelope, then the robot can access multiple locations and orientations, but the speed and precision are limited due to compounded errors and large mass of link elements
Solution Approach 1:
The patent inverts the traditional serial robot architecture by using a parallel robot structure where the end effector is supported by multiple independent legs connected to a fixed base. This inversion allows the robot to achieve full 6 DOF motion while the errors are averaged rather than compounded, and the distributed mass of multiple legs reduces the burden on individual components, enabling higher speed and precision.
2Measurement precision
If parallel robots are designed to achieve full 6 DOF motion, then motion precision improves due to error averaging, but heavy wrist elements must be added in series which increases mass and footprint
Solution Approach 1:
The patent makes each leg multi-functional by designing it to provide both positional support and orientational control. The feet at the ends of the legs can translate in two degrees of freedom and rotate, allowing each leg to contribute to both position and orientation of the end effector. This eliminates the need for separate heavy wrist elements, as the legs themselves perform both functions.
3Manufacturing precision
If parallel robots are designed with multiple legs to achieve 6 DOF motion, then precision improves through error averaging, but the robot requires a large footprint relative to work envelope
Solution Approach 1:
The patent utilizes the vertical dimension by allowing the legs to extend and retract, and the feet to translate vertically as well as horizontally. This three-dimensional movement capability allows the robot to achieve a large work envelope without requiring a large horizontal footprint. The end effector can access positions above and below the base plane, effectively using the Z-dimension to expand workspace.
Data Source
AI summary
Robots for moving relative to a surface, robotic systems including the same, and associated methods are disclosed. A robot includes a body, at least two legs, and at least two feet. Each leg has a proximal end region operatively coupled to the body at a respective body joint with one rotational degree of freedom and a distal end region operatively coupled to a respective foot at a respective foot joint comprising two rotational degrees of freedom. Each foot is configured to be translated relative to the surface with two degrees of translational freedom. Robotic systems include one or more robots and a surface along which the one or more robots are positioned to move. Methods of operating robots and of operating robotic systems include translating at least one foot of a robot to operatively move the body of the robot with six degrees of freedom.