KR-102962725-B1 - AUTONOMOUS CLEANING METHOD OF CLEANING SYSTEM FOR NICHE AREA OF SHIP HULL

KR102962725B1KR 102962725 B1KR102962725 B1KR 102962725B1KR-102962725-B1

Abstract

The object of the present invention is to provide an autonomous cleaning method for a cleaning system for a hull gap area that cleans the hull gap area using a multi-degree-of-freedom manipulator. To achieve the above objective, the autonomous cleaning method of a cleaning system for a hull gap area according to the present invention comprises: an initial position setting step for setting an initial position of a manipulator connected to a robot body; a laser scanning step in which a laser camera system of the manipulator scans a propeller; a path planning step for designing a cleaning path to clean the propeller scanned by the robot body; and a cleaning step in which a brush tool of the manipulator cleans the propeller according to the cleaning path.

Inventors

박대길
여태경
이영준
한종부
김성순
조수길
김형우

Assignees

한국해양과학기술원

Dates

Publication Date: 20260508
Application Date: 20220810

Claims (15)

Initial position setting step for setting the initial position of a manipulator connected to the robot body; A laser scanning step in which the laser camera system of the above manipulator scans the propeller; A path planning step for designing a cleaning path for cleaning the propeller scanned by the robot body; and A cleaning step comprising cleaning the propeller through a brush tool mounted on one end of the manipulator moving along the cleaning path; The above laser scanning step is, Characterized by including the step of the robot body operating the manipulator in a zigzag path to scan the propeller. Autonomous cleaning method of a cleaning system for hull crevice areas.
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In Article 1, The above zigzag path is characterized by considering the coverage range and resolution of the laser camera system to ensure the estimation of the relative position and attitude between the robot body and the propeller. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 1, The above laser scanning step is, The robot body is characterized by including a step of performing matching between point cloud map information and point cloud data obtained from the laser camera system. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 4, The above laser scanning step is, Characterized by including the step of generating a point cloud with matched data, Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 1, The above laser scanning step is, Characterized by including the step of obtaining a homogeneous transformation matrix between the axis of the robot body and the propeller axis. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 4, The above laser scanning step is, Characterized by the above robot body extracting the normal vector of the point of interest from the above point cloud map, Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 4, The above path planning step is, The robot body is characterized by including a step of extracting the boundary of the region of interest based on the depth of the acquired point cloud data set. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 8, The above path planning step is, Characterized by including the step of designing a cleaning path at the end of the manipulator so that the boundary of the region of interest is applied to all regions of interest. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 9, The above path planning step is, The robot body is characterized by including the step of using a dynamic simulator to identify collisions or singularities during path planning, and performing path replanning when a collision occurs in the robot body. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 8, The above cleaning step is, Characterized by including a step of controlling the velocity of each joint of the manipulator by considering the desired end-point position and attitude trajectory of the manipulator desired by the robot body. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 11, The robot body is characterized by correcting trajectory errors using a feedback controller and checking singularities and over-inputs using singular value decomposition analysis. Autonomous cleaning method of a cleaning system for hull crevice areas.
In Article 4, The above point cloud map information is, A step of collecting raw point cloud data of the propeller using the laser camera system; A step of extracting a region of interest from the collected point cloud raw data; A step of generating waypoints from the extracted region of interest; A step of generating a trajectory of the manipulator using the generated waypoints; A step of checking the collision between the generated trajectory and the propeller using a simulator; Characterized by being obtained by a preprocessing step including a step of determining whether the trajectory is a safe path by checking for the collision above. Autonomous cleaning method of a cleaning system for hull crevice areas.
A cleaning system for a hull crevice area that performs autonomous cleaning by a method according to any one of claims 1, 3 to 13.
A step of scanning the propeller by a laser camera system of a manipulator connected to the robot body; A step of performing matching between point cloud map information and point cloud data obtained from the laser camera system by the robot body; A step of generating a point cloud with matched data by the robot body above; A step of finding an optimal path through the rotation and translation of the above manipulator; A step of excluding the collision portion between the manipulator and the propeller; and Characterized by including the step of controlling the above manipulator. Autonomous cleaning method of a cleaning system for hull crevice areas.

Description

Autonomous cleaning method of cleaning system for a hull crevice area The present invention relates to an autonomous cleaning method for a cleaning system for a hull gap area, and more particularly to an autonomous cleaning method for a cleaning system for a hull gap area that cleans the hull gap area using a multi-degree-of-freedom manipulator. Generally, since ships operate with the lower part of the hull submerged in seawater, biofouling can occur on the bottom or sides located underwater. Here, biofouling refers to the attachment and accumulation of aquatic organisms on the submerged parts of a vessel. Various aquatic organisms such as water moss, barnacles, sea squirts, and seaweed can be attached to these aquatic organisms. These aquatic organisms pose a problem by increasing skin friction drag during ship operation, which causes a decrease in fuel efficiency. For example, foreign substances attached to the hull act as resistance during operation, reducing speed and consequently increasing fuel consumption. This not only raises operating costs due to increased fuel consumption but also increases emissions of gases such as CO₂, SOx, or NOx. In addition, biofouling can cause cavitation and turbulence on the bottom or side surfaces of a vessel located underwater. This has the problem of degrading the performance of sensors installed on the bottom of the ship. In addition, biofouling is pointed out as a major cause of the movement and influx of alien aquatic organisms, as marine organisms attached to vessels move along with the vessel's operation. As such, due to the harmful ecological effects of biofouling, the International Maritime Organization (IMO) and the Marine Environment Protection Committee (MEPC) define biofouling as a major cause of hull resistance and ecosystem disturbance. And many countries and organizations are enacting new regulations and laws regarding hull cleaning to reduce biological pollution. As such, various foreign substances and marine organisms attached to the hull not only damage the appearance of the ship but also act as resistance during operation, causing a decrease in the ship's speed and significantly increasing fuel consumption. Therefore, it is very important to periodically clean the various foreign substances and marine organisms attached to the hull. The part of the ship submerged underwater is classified into a flat hull surface and a crevice area. Here, a flat hull surface refers to a flat area coated with anti-fouling paint to prevent biofouling, and a gap area refers to an area with a complex shape such as a propeller, thruster, rudder hinge, etc. Antifouling paint for preventing biofouling cannot be applied to these crevice areas. Because the growth rate of biofouling is slow on flat hull surfaces due to the antifouling paint and flat shape, cleaning flat hull surfaces is relatively easy using conventional hull cleaning robots. However, since crevice areas are composed of various materials and have complex shapes and functions, there is a problem in that it is difficult to apply antifouling paints for biofouling. In addition, existing hull cleaning robots have the problem of being difficult to access crevice areas and difficult to attach the robot to the crevice areas. Conventionally, cleaning of hull crevices typically involved divers entering directly to remove foreign matter and marine life attached to the surface. However, due to the harsh working environment and severe physical exhaustion, it is difficult and time-consuming to thoroughly clean the exterior of the hull, and cleaning is impossible in areas with strong currents. In particular, for large vessels, the increased volume of cleaning work leads to longer underwater stays, posing significant risks to divers. Furthermore, since cleaning operations rely on the divers' visibility, there is a problem where the cleaning quality of the deep bottom of the vessel is significantly degraded. Therefore, as mentioned above, there is a problem in that it involves a lot of time and difficulty because divers still have to perform cleaning operations directly on crevice areas formed by complex shapes. However, most biofouling is found in small crevice areas rather than on flat hull surfaces. Even though these crevice areas account for a small proportion of the total hull area, up to 80% of biofouling is found in the crevice areas. Therefore, a new approach to robot cleaning for crevice areas is needed. FIG. 1 is a schematic diagram showing the concept of a bottom cleaning and recovery system in an autonomous cleaning method of a cleaning system for a hull gap area according to the present invention. FIG. 2 is a drawing showing the overall configuration of an autonomous cleaning system including a manipulator for cleaning a gap area of a hull in an autonomous cleaning method for a hull gap area according to the present invention. FIG. 3 is a flowchart showing the overall flow of the autonomous cleaning method of a cle