Robot Arm Joint Control for Stable Imaging and Intuitive Handling
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Solution Overview
Problem
Current robot arm apparatuses, particularly in medical settings, face challenges in providing optimal operation due to difficulties in balancing movement, ensuring imaging stability, and accommodating user demands for intuitive control, especially when performing tasks that require physical interaction and precise positioning.
Innovation Solution
A robot arm apparatus that controls the viscosity of its joint units based on their state and an enlargement factor, utilizing generalized inverse dynamics and ideal joint control to achieve precise positioning and stable operation, allowing for flexible movement and intuitive control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If position control is used for robot arm apparatus, then the system configuration is simple and control is convenient, but the robot cannot easily deal with external force flexibly and is not suitable for physical interaction tasks
Solution Approach 1:
The patent implements dynamic switching between position control and force control modes based on the operational requirements. The control mode is changed according to whether the robot arm is in contact with the patient or performing imaging tasks, allowing the system to adapt its control characteristics in real-time without requiring permanently complex hardware
2Adaptability or versatility
If force control is used for robot arm apparatus, then the robot can implement soft control suitable for physical interaction, but the system configuration becomes complicated
Solution Approach 1:
The system dynamically switches between position control and force control modes based on operational context. When physical interaction is required (e.g., during surgical procedures), force control is activated; when imaging or positioning is needed, position control takes over. This dynamic approach allows the system to have complex capabilities without permanently complex configuration
3Ease of operation
If the robot arm is balanced to enable operation with light force, then the arm can be operated easily, but the arm moves in response to light force making it difficult to ensure imaging stability and freedom of imaging
Solution Approach 1:
The patent changes the control parameters dynamically based on the operational state. When the imaging unit is locked to a patient site, the system increases the stiffness or damping parameters to prevent unwanted movement from light forces. When the imaging unit needs to be repositioned, the parameters are adjusted to allow easier movement. This parameter adjustment resolves the contradiction between ease of operation and imaging stability
4Stability of the object's composition
If the robot arm is controlled by position control to replace balance arm, then the imaging stability can be improved, but it is difficult to meet user demand for intuitive control and high operability
Solution Approach 1:
The system implements dynamic switching between position control and force control modes. During imaging tasks where stability is critical, position control is used. During surgical tasks where intuitive control is needed, force control is activated. This dynamic mode switching allows the system to provide both imaging stability and intuitive control at different times without compromising either capability
Data Source
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AI summary
A robot arm apparatus according to the present disclosure includes: one or a plurality of a joint unit that joins a plurality of links constituting a multi-link structure; an acquisition unit that acquires an on-screen enlargement factor of a subject imaged by an imaging unit attached to the multi-link structure; and a driving control unit that controls driving of the joint unit based on a state of the joint unit and the enlargement factor.