Augmented Jacobian Control for Redundant Surgical Manipulators
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Solution Overview
Problem
Current surgical robotic systems face challenges in limiting unnecessary movement of manipulator arms during tasks, avoiding collisions between arms and patients, and expanding the range of motion without increasing mechanical complexity or cost, while maintaining dexterity.
Innovation Solution
The implementation of highly configurable surgical robotic manipulators with additional redundant joints, utilizing an augmented Jacobian to calculate joint velocities that allow for auxiliary movements such as collision avoidance and reconfiguration, while maintaining a desired end effector state, and incorporating a processor to drive these movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional redundant joints are added to manipulator arms, then range of motion and dexterity are improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical constraints with software-based control. Instead of using mechanical linkages to physically limit manipulator movement, the system uses a null-space controller that calculates and applies compensation forces through the augmented Jacobian matrix, achieving the same effect through computational methods.
Solution Approach 2:
The patent changes the control parameters by augmenting the Jacobian matrix with null-space components. This mathematical transformation allows the system to independently control end effector position and manipulator configuration, enabling range of motion limits to be enforced through parameter adjustment rather than mechanical modification.
2Reliability
If null-space control is implemented to limit manipulator movement, then safety and collision avoidance are improved, but control system complexity increases
Solution Approach 1:
The augmented Jacobian matrix serves multiple functions simultaneously: it controls end effector positioning, enforces range of motion limits, prevents collisions, and maintains manipulator configuration. This multi-functionality reduces the need for separate control systems for each function.
Solution Approach 2:
The null-space controller automatically adjusts manipulator configuration based on real-time conditions without requiring external intervention. The system self-regulates by continuously calculating compensation forces that maintain safety constraints while allowing task execution.
3Adaptability or versatility
If redundant joints are used for auxiliary movements, then collision avoidance capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive mechanical collision avoidance mechanisms with software-based null-space control. Instead of adding physical sensors, actuators, or mechanical stops, the system uses mathematical calculations to predict and prevent collisions through virtual constraints.
Solution Approach 2:
The patent creates a virtual model of the manipulator and its environment in the null-space, allowing collision avoidance to be simulated and enforced computationally rather than requiring physical prototypes or redundant mechanical components.
Data Source
AI summary
Devices, systems, and methods for providing commanded movement of an end effector of a manipulator while providing a desired movement of one or more joints of the manipulator. Methods include augmenting a Jacobian so that joint movements calculated from the Jacobian perform one or more auxiliary tasks and/or desired joint movements concurrent with commanded end effector movement, the one or more auxiliary tasks and/or desired joint movements extending into a null-space. The auxiliary tasks and desired joint movements include inhibiting movement of one or more joints, inhibiting collisions between adjacent manipulators or between a manipulator and a patient surface, commanded reconfiguration of one or more joints, or various other tasks or combinations thereof. Such joint movements may be provided using joint velocities calculated from the pseudo-inverse solution of the: augmented Jacobian. Various configurations for systems utilizing such methods are provided herein.