Marine Propulsion Buffer Control for Obstacle-Aware Maneuvering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous and semi-autonomous marine vessel control systems face challenges in navigating complex marine environments with additional degrees of freedom, where maintaining a safe distance from obstacles and avoiding collisions is crucial due to factors like current, wind, and waves, while existing systems lack effective control over vessel acceleration limits and buffer zones.
Innovation Solution
A propulsion control system that calculates and maintains a buffer distance around the marine vessel, limiting operator control authority to prevent collisions by determining maximum velocity limits based on proximity measurements and acceleration limits, and automatically adjusts propulsion to maintain this buffer zone, using proximity sensors and velocity control algorithms to ensure safe navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If autonomous control is implemented to maintain buffer distance and prevent collisions, then safety and collision avoidance are improved, but operator control authority and maneuverability are reduced
Solution Approach 1:
The control system dynamically adjusts the buffer distance parameter based on vessel velocity, allowing the safety margin to vary with operational conditions. At higher velocities where collision risk is greater, the buffer distance increases automatically, while at lower velocities the buffer distance decreases, granting the operator more control authority when the situation permits.
Solution Approach 2:
The system modifies the buffer distance parameter as a function of vessel velocity, creating a velocity-dependent safety zone. This parameter change allows the same control system to provide both strong collision avoidance at high speeds and greater operator flexibility at low speeds, effectively resolving the contradiction between safety and maneuverability.
2Reliability
If velocity limits are imposed to maintain buffer zone, then collision prevention is improved, but navigation speed and productivity are reduced
Solution Approach 1:
The velocity limit is not a fixed constraint but a dynamic parameter that adjusts based on the distance to obstacles and the current buffer zone requirements. When the vessel is far from obstacles, higher velocities are permitted, maintaining productivity. When approaching obstacles or when the buffer zone requires larger margins, the velocity limit automatically decreases to ensure collision prevention.
Solution Approach 2:
The control system continuously monitors the vessel's position relative to obstacles and the current buffer zone status, using this feedback to dynamically adjust velocity limits. This closed-loop control ensures that velocity restrictions are applied only when and where necessary for collision prevention, rather than imposing blanket speed limits that would reduce overall navigation productivity.
3Reliability
If buffer distance is increased to ensure safety margin, then collision avoidance capability is improved, but the operational area and maneuverability are reduced
Solution Approach 1:
The buffer distance is implemented as a dynamic parameter that expands and contracts based on vessel velocity and proximity to obstacles. At high velocities, the buffer distance automatically increases to provide adequate safety margin, while at low velocities the buffer distance decreases, allowing the vessel to operate closer to obstacles when the situation permits, thereby maximizing the effective operational area.
Data Source
AI summary
A method of controlling a propulsion system on a marine vessel includes receiving proximity measurements describing locations of one or more objects with respect to the marine vessel, receiving a command vector instructing magnitude and direction for propulsion of the marine vessel with respect to a point of navigation for the marine vessel, and then determining a funnel boundary based on the command vector. An object is identified based on the proximity measurements and determined to be within the funnel boundary, and then a propulsion adjustment command is calculated based on the command vector and an angle of the object with respect to the point of navigation. At least one propulsion device is then controlled based on the propulsion adjustment command in order to avoid the object.