1. Description of the Competition
AUV (Autonomous Underwater Vehicle), one of the main categories of underwater vehicles, which integrates controllers, sensors, computer software and power, and it has autonomous perception and intelligent decision-making capabilities, and navigates with its own power. With the ability of autonomous navigation and sailing, it can conduct large-scale navigation and detection missions, and is often used in marine aerial surveying, target search and marine exploration.
The competition tests perception and intelligent control of the AUV (Autonomous Underwater Vehicle) by examining its completion of various underwater tasks. The tasks of competition include: passing the qualification gate, hitting floating ball, precise work and rising onto the flotation frame by tracing acoustics signals. Underwater navigation markers with Aruco will help and guide the AUV during the first 3 tasks; Aruco markers or a 37.5kHz acoustic beacon will guide the AUV in the final task.
1.1 Venue & Site
Site Size: length not less than 20m, width not less than 8m, depth from 1.3m to 2.8m.
Figure 1 Competition Site Diagram
1.2 Competition Requirements
1.2.1 Size and Weight
The weight of the vehicle shall not exceed 30 kg (weight in air). If the weight is below 30kg, corresponding bonus points will be applied; if the weight exceeds 30kg, points will be deducted for overweight. Vehicles weighing 45 kg or more are not allowed to compete.
The vehicle must fit into a cube size of 1000mm*1000mm*2000mm.
The team can use 2 vehicles if their total mass and dimensions do not exceed the specified limits.
1.2.2 Power Supply
The power supply can only be rechargeable battery, with the voltage not exceeding 72V. It is forbidden to use a 220V AC power supply.
1.2.3 Emergency Switch
Each vehicle must have a reliable security (emergency) switch to shut down the system and stop all propellers during an emergency. The switch should be placed in a prominent position on the surface of the vehicle, which can be easily operated by the diver in case of emergency.
1.2.4 Others
A. During the competition, except the balls for competition, no parts or accessories can be separated from the vehicle and nothing can be thrown into the pool. There should also be no leakage of oil or other pollution.
B. During the competition, once the AUV (or one of the AUVs) floats onto the surface, the attempt ends.
C. The AUVs must autonomously pass all tests. Teams are prohibited from touching the water in pool with any device or using any wireless device to remotely control the vehicles.
D. Total attempt time for each team is 30 minutes, 10 minutes for debugging and preparation and 20 minutes for the competition. The team announces the start of the competition and the referee starts the clock for 10 minutes The AUV should pass the gate within 10 minutes after the starting of the race. The attempt ends when the AUV floats.
E. If the participants consider that the result of the current attempt is unsatisfactory, it can be terminated at any time, then a second attempt may be made. When the team members announce the termination of the current attempt, the 20-minute timer will be suspended and the score of this attempt will be invalid. The robot will be salvaged by the staff, and the timer will continue when the robot is handed over to the team members.
F. A team member can be appointed to contact the judge, participate in the draw and stop the attempt, if necessary.
G. Only if all the four tasks have been completed with scores at the end of the competition, additional points can be awarded for the remaining time.
2. Introduction to Competition Tasks
2.1 Passing the Qualification Gate
2.1.1 Description
It is allowed to continue to complete the tasks only after the AUV has passed the qualification gate. Otherwise, points will not be counted for completing following tasks.
2.1.2 Props Description
The qualification gate is a rectangular frame made of orange PVC pipes, consisting of orange uprights and buoyant beams, the color of the gate is orange, with the frame of 2500mm × 1500mm, the specific dimensions are shown below:
Figure 2 Qualification Gate
Behind the gate, there is a plate with a Aruco marker for the positioning and guiding (as shown below). All Aruco markers are different. The size of the plate is 400mmx400mm. The rotation angle (from -180 to 180 degrees) is encrypted in the Aruco markers to guide the AUV to the second task. Its position is shown in the figures below.
Figure 3 Aruco marker for Positioning and Guiding
Figure 4 Placement and Position of Aruco Marker
2.1.3 Instruction of Rules
The AUV launches to dive in the starting area and begins to complete the tasks. The attempt will end when the vehicle floats to the surface of the water outside the starting area.
Here is the formula to calculate the score of passing the gate:scores = (base points + additional points) * difficulty coefficient. Passing the gate underwater, the vehicle can get both base points and qualification of attending the subsequent tasks of the game.
Chanllenge points of skilled passing are given for rotations along the yaw axis or the roll axis during the passing process. For horizontal rotation (Z axis) , every 90-degree rotation can be awarded 25 points, up to a maximum of 200 points, but reverse rotation will deduct points back. The vehicle can also roll along the X axis or Y axis when it passes the gate, every 90-degree rotation can be awarded 50 points, up to a maximum of 400 points, but reverse rotation will deduct points back.
More detailed rules for scoring can be found in Appendix 1.
2.2 Hitting Floating Ball
2.2.1 Description
In this task, the vehicle needs to hit the balls placed under water in the correct order that is determined by the draw.
If the order is not followed subsequently, the points will be reduced accordingly.
The Aruco marker behind the ball will guide the AUV to the next task, where the size of the Aruco marker is 40mm*40mm, and the guide angle is from -180 degrees to 180 degrees.
2.2.2 Props Description
Three floating balls of different colors will be placed in the pool, each tied to a line with the other end fixed to the bottom of the pool by a heavy object. The distance between the floating ball and the surface of water is 0.6m~1.2m, and the heights of the floating balls are different, as shown below:
Figure5. Schematic Diagram of Floating Ball
3 standard inflatable floats with a diameter of 295 mm are used as floating balls. Balls with the help of a rope and a load, are installed in the water at different depths. The horizontal distance between the centers of the floats is about 2m.
2.2.3 Instruction of Rules
Before the starting of the competition, a draw is held to determine the order in which the balls to be touch. To get base points, the vehicle needs to touch the balls in any order. If the order is followed subsequently, then additional points are awarded.
The Aruco marker behind the floating balls will guide to the next task.
Figure 6 Aruco marker for Positioning of Underwater Precise Work
More detailed rules for scoring can be found at the end.
2.3 Precise Work
2.3.1 Description
The vehicle catches white balls from the display basket, and drops them into the basket cells. The smaller the cell is, the more points the vehicle can get. Besides one yellow golf ball carried by the vehicle, another 3 extra balls (white) can be caught from the display basket and cast into the basket cells. A plate with a Aruco marker is placed near the basket cells to guide the vehicle to the next task.
There will be an acoustic beacon near the basket cells, which will operate at a frequency of 30kHz.
2.3.2 Props Description
A display basket will be installed at the bottom of the pool. Negative buoyance exists in water. Three white balls are placed in the display basket. The dimensions are shown in the following figure:
Figure 7 Underwater Golf Balls Display Basket
A storage basket with three cells of different sizes will also be installed next to the frame at the bottom. The vehicle needs to grab the golf balls from the display basket at the bottom and put it into basket cells, as shown below:
Figure 8 Storage Basket Cells
Figure 9 Schematic Diagram of the Storage Basket Size (mm)
Figure 10 Underwater 30K Acoustic Beacon
The underwater precision operation area is equipped with 30k CW acoustic beacon to help the vehicle locate itself in the area.
Figure 11 Aruco marker for Underwater Precision Operation
A Aruco marker is also equipped in the area, specific Aruco marker needs to be further determined to be used to help the vehicle locate itself.
2.3.3 Instruction of Rules
The vehicle can get scores by casting balls in any cells of the basket. The smaller the cell is, the more points the vehicle can get.
2.4 Rising onto the Flotation Frame
2.4.1. Description
The vehicle needs to dive through the flotation frame at the destination guided by an acoustic beacon operating at a frequency of 37.5 kHz, and then rise onto the flotation frame to complete the task. The collar is fixed on the surface of the water and under the frame is an acoustic beacon operating at a frequency of 37.5 kHz set on a red plate. The plate itself can also be used for the location of the vehicle by light beacon.
2.4.2 Props Description
Figure 12 Schematic Diagram of Props for Rising through Floating Frame Guided by Acoustic Beacon
Figure 13 37.5k CW Signal Acoustic Beacon
A 37.5k CW signal acoustic beacon is arranged below the frame for the guidance of the vehicle. Meanwhile, there is a red plate at the bottom of the acoustic beacon that helps the vehicle locate itself. The diameter of red plate is 400mm.
The frame is an octagonmade of 8 PVC pipes with a length of 620mm.
Figure 14 Schematic Diagram of the Floating Frame
((Since the 60° elbow is not easy to buy, it is changed to octagon))
2.4.3 Instruction of Rules
It is judged to be a successful floating if the vehicle rises to float out of the frame and stays for at least 3 seconds. The vehicle gets full scores if it does not touch the frame, otherwise penalty points will be given.
After completing all tasks, the AUV resurfaces outside the finish lap and simultaneously requests the end of the competition. The referee stops the clock and the rest of the time is converted into additional points for remaining time.
3.Scoring Criteria
The total score consists of work points completed within 20 minutes and the bonus points, in which the bonus points are awarded only if all the tasks are completed within 20 minutes. Grades are sorted by total score.
The attached schematic diagrams are for reference only, and the real props and facilities may be different.
The Competition Organizing Committee reserves the right of final interpretation.
