Predictive End-Effector Positioning for Continuum Robot Control
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Solution Overview
Problem
Current techniques for continuous positioning control of interventional devices, particularly in clinical settings, face challenges due to the complexity of continuum robot structures and environmental factors, leading to inaccuracies and difficulties in maintaining consistent control over soft-tissue manipulation.
Innovation Solution
A predictive model-based approach for feed-forward and feedback positioning control, utilizing forward and inverse predictive models, along with data collection techniques to improve the accuracy and consistency of positioning control, regardless of environmental changes or anatomical differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a static model with nonlinear differential equations is used to account for continuum robot deformation, then the robot's positioning accuracy is improved, but the model becomes susceptible to environmental changes and manufacturing inaccuracies
Solution Approach 1:
The patent applies preliminary action by training the neural network model beforehand using extensive simulation data that encompasses various environmental conditions, manufacturing tolerances, and operational scenarios. This pre-training enables the model to inherently account for these variations without requiring recalibration, thus improving reliability while maintaining positioning accuracy through feedforward prediction capabilities.
Solution Approach 2:
The patent replaces the traditional static mechanical model with nonlinear differential equations with a data-driven neural network model. This substitution allows the system to learn complex deformation patterns from data rather than relying on explicit mathematical formulations, making the model more robust to environmental changes and manufacturing inaccuracies while maintaining high positioning accuracy.
2Adaptability or versatility
If the degree of freedom of the robot is increased to improve maneuverability, then the robot's adaptability is improved, but the kinematics complexity increases
Solution Approach 1:
The patent replaces complex analytical kinematics calculations with a neural network-based predictive model. The network learns the mapping between joint configurations and end-effector positions from simulation data, eliminating the need for real-time solution of complex kinematic equations. This substitution maintains high maneuverability while significantly reducing computational complexity and control difficulty.
Solution Approach 2:
The patent performs preliminary computation during the training phase by pre-computing the relationship between joint space and task space across the entire workspace. This offline training enables the controller to simply query pre-learned mappings during operation, avoiding real-time complexity while maintaining full maneuverability of the high-degree-of-freedom robot.
3Measurement precision
If predictive models are used for feedforward positioning control, then positioning precision is improved, but the system requires accurate calibration and is sensitive to wear and tear
Solution Approach 1:
The patent performs comprehensive calibration and adaptation during the offline training phase, where the neural network learns from simulation data that incorporates manufacturing tolerances and expected wear patterns. This preliminary adaptation embeds compensation strategies into the model itself, reducing the need for frequent recalibration while maintaining high positioning precision even as components wear.
Solution Approach 2:
The patent employs parameter changes by training the neural network to be robust to variations in mechanical parameters such as link lengths, joint clearances, and material properties. The model learns to compensate for these parameter variations through exposure to diverse training scenarios, thereby maintaining positioning precision without requiring precise calibration of each individual parameter.
Data Source
AI summary
A positioning controller (50) including a forward predictive model (60) and/or inverse control predictive model (70) for positioning control of an interventional device (30) including a portion (40) of an interventional device. In operation, the controller (50) may apply the forward predictive model (60) to a commanded positioning motion of the interventional device (30) to render a predicted navigated pose of the end-effector (40), and generate positioning data informative of a positioning by the interventional device (30) of said portion of interventional device (40) to a target pose based on the predicted navigated pose of said portion (40). Alternatively, antecedently or subsequently, the controller (50) may apply the control predictive model (70) to the target pose of the portion of interventional device (40) to render a predicted positioning motion of the interventional device (30), and generate positioning commands controlling a positioning by the interventional device (30) of said device portion (40) to the target pose based on the predicted positioning motion of the interventional device (30).


