Medical Tool Manipulator Sensor Fusion for Tip Vibration Control
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Solution Overview
Problem
Robotic manipulators experience undesirable vibrations due to flexibility and low mechanical resonance, leading to poor control and deviation from commanded trajectories, especially during medical procedures, affecting the remote center of motion and tool positioning.
Innovation Solution
A system that combines data from joint encoders and sensor systems to generate accurate tool tip estimates, allowing for improved control of robotic manipulators by reducing vibrations and settling times through a master/slave control mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the robotic manipulator uses flexible links and joints to achieve compliance, then adaptability is improved, but stability deteriorates due to under-damped vibrations
Solution Approach 1:
The system uses sensors to detect vibrations at the tool tip and feeds this information back to the controller, which then generates compensatory control signals to actively suppress the vibrations, resolving the contradiction between compliance and vibration damping
Solution Approach 2:
The patent replaces passive mechanical damping elements with an active control system that uses sensors and actuators to dynamically counteract vibrations, achieving vibration suppression without compromising the mechanical compliance of the manipulator
2Strength
If the robotic manipulator has large link masses and inertias, then strength is improved, but stability deteriorates due to low mechanical resonance
Solution Approach 1:
The control system continuously monitors the manipulator's motion and detects resonant vibrations, then applies real-time compensatory control signals to suppress these vibrations, allowing the use of massive links for strength without suffering from resonance problems
3Productivity
If the robotic manipulator operates at high speed, then productivity is improved, but measurement precision deteriorates due to vibrations
Solution Approach 1:
The system uses high-speed sensors to detect tool tip vibrations and positions, and the controller processes this feedback information to generate compensatory signals that maintain positioning precision even during high-speed operations
Solution Approach 2:
The patent employs vibration cancellation techniques where the control system generates counter-vibrations to cancel out the harmful vibrations caused by high-speed motion, thereby maintaining measurement and positioning precision
Data Source
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AI summary
A system comprises a robotic manipulator for control of motion of a medical tool. The robotic manipulator including a joint and a link connected to the joint. The link is configured to connect to the medical tool. A processing unit of the system is configured to receive first data from an encoder of the joint. A first tool tip estimate of a first parameter of a tool tip coupled at a distal end of the medical tool is generated using the first data. The first parameter of the tool tip is a position or a velocity of the tool tip. Second data is received from a sensor system located at a sensor portion of the link or the medical tool. The joint is controlled based on a first difference between the first tool tip estimate and a second tool tip estimate generated using the first and second data.