Robotic Medical Control for Constant Overshoot Under Network Delay
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Solution Overview
Problem
Robotic medical device systems face challenges in maintaining consistent movement and control due to variations in delay associated with network communications, leading to issues such as overshoot and overtravel during robotic interventional procedures.
Innovation Solution
A controller is configured to control the robotic medical device to maintain a substantially constant overshoot and maximum overtravel distance by adjusting movement and velocity in response to control signals received via a network, with mechanisms in place to handle delays within acceptable thresholds and disable operations when delays exceed critical levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If network communication is used to transmit control signals, then remote operation capability is improved, but control delay and overshoot increase
Solution Approach 1:
The system performs preliminary actions by predicting the desired device state based on historical control signals and system dynamics models before actual control signals arrive. This prediction compensates for network delays by preparing control commands in advance, reducing the effective control delay while maintaining remote operation capability
Solution Approach 2:
The system implements feedback mechanisms that continuously monitor actual device state and compare it with predicted states. This feedback loop enables real-time adjustment of control signals to compensate for network-induced delays and overshoot, maintaining stable remote operation despite communication latency
2Adaptability or versatility
If control signals are transmitted over network, then remote control flexibility is improved, but overshoot and overtravel occur due to delay variations
Solution Approach 1:
The system employs dynamic control strategies that adapt control parameters in real-time based on current system state and delay conditions. By making the control system dynamic rather than static, it can adjust to varying network delays while maintaining movement precision and preventing overshoot, thus preserving both remote control flexibility and positioning accuracy
Solution Approach 2:
The system changes control parameters such as gain values, prediction horizons, and velocity limits based on detected delay conditions. These parameter adjustments allow the system to maintain precise movement control under varying network latency conditions, preventing overshoot while preserving remote control adaptability
3Productivity
If velocity control is increased to improve procedure speed, then productivity is improved, but overshoot and overtravel increase due to network delay
Solution Approach 1:
The system performs preliminary velocity planning based on predicted trajectories and delay compensation before actual movement execution. By pre-calculating velocity profiles that account for network latency, the system can maintain higher speeds while preventing overshoot, thus improving productivity without sacrificing control stability
Solution Approach 2:
The system uses feedback from actual device position and velocity to continuously adjust control commands. This real-time feedback enables the system to maintain high productivity by allowing faster velocities while automatically correcting for overshoot caused by network delays, thereby preserving control stability
Data Source
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AI summary
A robotic medical device system includes a robotic medical device and a controller. The controller is configured to control, in response to one or more control signals, movement of the robotic medical device to maintain a substantially constant overshoot for different step responses of the robotic medical device system independent of variations in a delay associated with control of the robotic medical device, the one or more control signals received via a network.