Magnetic Coupler Calibration for Robotic Arm End Effectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current calibration methods for robotic systems in computer-aided surgical systems are time-consuming and require additional hardware, especially for systems like the ROBODOC™ Surgical System, where the mechanical digitizer must be removed and re-assembled to calculate coordinate transformations, taking several hours.
Innovation Solution
A magnetic coupler system that allows the mechanical digitizer to be magnetically coupled to the robotic arm's end-effector, enabling simultaneous movement and measurement at multiple calibration locations without detachment, using a rotatable ball and socket connection for three-degrees-of-freedom rotation, and a calibration algorithm to determine kinematic parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the mechanical digitizer is removed and re-assembled to calculate coordinate transformations, then the calibration accuracy is improved, but the calibration time increases to several hours
Solution Approach 1:
The magnetic coupler is pre-installed on the end-effector before the calibration procedure. This preliminary setup eliminates the need to remove and re-assemble the mechanical digitizer during calibration, reducing calibration time from several hours to minutes while maintaining accuracy through the magnetic coupling mechanism that enables coordinate transformation calculation.
Solution Approach 2:
The magnetic coupler acts as an intermediary component between the mechanical digitizer and the end-effector. It provides a removable interface that allows the digitizer to be magnetically coupled during calibration and easily detached afterward, avoiding the time-consuming process of mechanical removal and re-assembly while preserving calibration accuracy.
2Measurement precision
If additional hardware such as reference parts and calibration probes are used, then the calibration precision is improved, but the device complexity increases
Solution Approach 1:
The magnetic coupler serves multiple functions: it provides a mounting interface for the mechanical digitizer, enables coordinate transformation calculation, and allows easy attachment/detachment. This multi-functional component replaces the need for separate reference parts and calibration probes, reducing hardware complexity while maintaining calibration precision.
Solution Approach 2:
The invention extracts the essential calibration function from the complex assembly of reference parts, calibration probes, and mechanical coupling mechanisms. By isolating the calibration capability into the magnetic coupler system, the patent eliminates unnecessary hardware while preserving measurement precision.
3Adaptability or versatility
If the mechanical digitizer is removed to provide workspace, then the robotic arm mobility is improved, but the calibration process time increases
Solution Approach 1:
The magnetic coupler provides a dynamic, removable connection between the mechanical digitizer and the end-effector. During calibration, the digitizer is magnetically coupled for precision measurement. After calibration, it can be quickly detached to provide full workspace for the robotic arm. This dynamic setup eliminates the need for permanent removal while maintaining both calibration accuracy and operational mobility.
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 method significantly reduces calibration time to less than 5 minutes, allowing for efficient recalibration between surgical procedures and improving surgical precision, leading to faster recovery and longer implant longevity.
Implementation Method 1
The ball is removably coupled to the magnetic coupler via the magnetic portion on the receiving face
Data Source
AI summary
An apparatus for calibration of a robotic arm having an end effector of a robot includes a magnetic coupler having a body, a receiving face, a mounting member, and a magnetic portion. The mounting member is configured to fixedly connect to the end effector of the robotic arm. A mechanical digitizer probe having a ball and a handle are provided, where the ball is fixedly attached to a distal end of the handle and the ball is removably coupled to the magnetic coupler via the magnetic portion on the receiving face to form a rotatable ball and socket connection, and where a proximal end of the handle is adapted to be attached to a mechanical digitizer associated with the robot. A method for calibration of the robotic arm of a robot is also detailed.