Manipulator Arm Null-Space Path Tracking for Collision Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current robotic surgical systems face challenges in providing consistent and predictable movement of manipulator arms during minimally invasive surgeries, often resulting in excessive movement outside the patient, which can lead to collisions and increased complexity, while also requiring additional training and time for setup due to the high number of degrees of freedom and redundant joints.
Innovation Solution
The system employs a processor to calculate coordinated joint movements using holonomic or position-based constraints within the joint-space or Cartesian-coordinate space, allowing for movement within a null-space to maintain desired end effector positions and prevent collisions, while also enabling reconfiguration and manual articulation of joints to optimize the range of motion and reduce mechanical complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If redundant joints and high degrees of freedom are used in robotic manipulator arms, then surgical dexterity and range of motion are improved, but movement consistency and predictability deteriorate
Solution Approach 1:
The system dynamically changes the null-space parameters and constraint weights during operation. The controller adjusts the null-space velocity commands based on real-time manipulation commands and collision risk assessments, allowing the manipulator to maintain consistent end-effector movement while adapting joint configurations to avoid collisions and improve dexterity.
2Adaptability or versatility
If redundant joints and high degrees of freedom are used in robotic manipulator arms, then surgical dexterity and range of motion are improved, but collision risk increases
Solution Approach 1:
The system continuously monitors manipulator position, velocity, and environmental constraints, then feeds this information back to the controller. The controller uses this feedback to dynamically adjust null-space commands and generate collision avoidance torque commands, creating a closed-loop system that actively prevents collisions while maintaining surgical dexterity.
Solution Approach 2:
The system proactively generates collision avoidance torque commands before collisions occur by predicting potential collision risks based on current manipulator state and planned trajectories. The null-space control preemptively adjusts joint configurations to avoid obstacles and other manipulators, preventing harmful interactions before they happen.
3Adaptability or versatility
If redundant joints and high degrees of freedom are used in robotic manipulator arms, then surgical dexterity is improved, but setup time and training requirements increase
Solution Approach 1:
The system performs self-positioning and selfconfiguration during operation by automatically adjusting null-space parameters and joint configurations based on real-time commands and environmental feedback. This eliminates the need for manual setup and reconfiguration by operators, reducing setup time and training requirements while maintaining full utilization of the manipulator's dexterity capabilities.
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
Devices, systems, and methods for providing a desired movement of one or more joints of a manipulator arm having a plurality of joints with redundant degrees of freedom while effecting commanded movement of a distal end effector of the manipulator. Methods include defining a constraint, such as a network of paths, within a joint space defined by the one or more joints and determining a movement of the plurality of joints within a null-space to track the constraints with the one or more joints. Methods may further include calculating a reconfiguration movement of the joints and modifying the constraints to coincide with a reconfigured position of the one or more joints. Various configurations for devices and systems utilizing such methods are provided herein.