# 9.3 Collision Avoidance

The third category is collision avoidance. The vessel must reach a destination without colliding with realistic obstacles. It should navigate the waters according to the COLREG. The moving obstacles should be expected to either head directly towards the ASV, or simply cross its path. The ASV should pass the moving obstacle on the correct side. The task will have two different scenarios, one where a boat in on a 90 degree collision course with the ASV. The other one where the otter will drive parallel to the ASV before turning onto a collission course at random.

### Task Rules

* 2 attempts per collision situation.
* Set speed for task: **2 knots.**
* At the start of an attempt, ASV must immediately accelerate to set speed for task.

### Task 3.1

<figure><img src="https://3624847333-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FELthsdxD5tIDQE3K425p%2Fuploads%2FAcDJe8quZlUaXnEKGYeZ%2FTask%203.1.png?alt=media&#x26;token=185b8197-0eeb-4c08-af08-450ce5810eec" alt=""><figcaption><p>Task 3.1</p></figcaption></figure>

**OBJECTIVE:**

The ASV will go from GPS-point 5 to GPS-point 6, and face the marker vessel on its path. In this task the marker vessel enter from starboard side. The ASV shall detect the marker vessel and pass it safely.

**ELEMENTS:**

| Element                                    | Description                                       | Dimensions                                                                                              |
| ------------------------------------------ | ------------------------------------------------- | ------------------------------------------------------------------------------------------------------- |
| <p>Marker vessel<br>The Otter of Njord</p> | <p>Speed: 2.5 knots<br>Angle: 80-100 degrees</p>  | 2 m x 1.08 m x 1 m (LxWxH)                                                                              |
| 2 gates                                    | Pair of red and green buoys                       | <p>5m between buoys,<br>20-80 meters between gates</p>                                                  |
| Red buoys                                  | Red buoys                                         | <p>Height cylinder: 40cm </p><p>Diameter cylinder: 14cm<br>Height Buoy: 40cm<br>Diameter Buoy: 35cm</p> |
| Green buoys                                | Green                                             | <p>Height cylinder: 40cm </p><p>Diameter cylinder: 14cm<br>Height Buoy: 40cm<br>Diameter Buoy: 35cm</p> |
| 2 GPS-coordinates                          | <p>GPS-point 5 and 6<br>Provided before start</p> | N/A                                                                                                     |

**TASK GUIDELINES:**

Step 1:

You are given the clear signal from the Chief Marshall to steer your vessel to GPS-point 5 of Task 3.1. This shall be done through Remote Control.

Step 2:

Once given the go-ahead from the Chief Marhsall, you must switch to Autonomous Mode, and your ASV may start its attempt at Task 3.1. Your turn starts when the ASV crosses the first gate.

Step 3:

Once observing the Otter vessel, your ASV shall signal the detection, and safely maneuver around the marker vessel.

Step 4:

Once you pass the final gate of the Task 3.1, your attempt finishes. Then your ASV shall go to GPS-point 6 and stay stationary there, waiting for go-ahead to proceed. You may switch to Remote Control if needed at the GPS-point.

Step 5:

Once given the go-ahead, the ASV must be steered, in Remote Control, back to GPS-point 5, without crossing the course.&#x20;

Step 6:&#x20;

When the Chief Marshall gives the go-ahead, you may steer the ASV safely back to the dock in Remote Control.

***

### Task 3.2

<figure><img src="https://3624847333-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FELthsdxD5tIDQE3K425p%2Fuploads%2FjaNne96Y33OZmPONt8gQ%2FTask%203.2.png?alt=media&#x26;token=5062502e-bdc1-40a9-a5b3-4c81840ebc6a" alt=""><figcaption><p>Task 3.2</p></figcaption></figure>

**OBJECTIVE:**

The ASV will go from GPS-point 7 to GPS-point 8, and face the marker vessel on its path. In this task the marker vessel will drive parallel to the ASV before turning onto a collission course at random. The ASV shall detect the marker vessel and pass it safely.

**ELEMENTS:**

| Element                                    | Description                                                | Dimensions                                                                                              |
| ------------------------------------------ | ---------------------------------------------------------- | ------------------------------------------------------------------------------------------------------- |
| <p>Marker vessel<br>The Otter of Njord</p> | <p>Speed: <strong>2.5</strong> knots<br>Angle:  random</p> | 2 m x 1.08 m x 1 m (LxWxH)                                                                              |
| 2 gates                                    | Pair of red and green buoys                                | <p>5m between buoys,<br>20-80 meters between gates</p>                                                  |
| Red buoys                                  | Red buoys                                                  | <p>Height cylinder: 40cm </p><p>Diameter cylinder: 14cm<br>Height Buoy: 40cm<br>Diameter Buoy: 35cm</p> |
| Green buoys                                | Green                                                      | <p>Height cylinder: 40cm </p><p>Diameter cylinder: 14cm<br>Height Buoy: 40cm<br>Diameter Buoy: 35cm</p> |
| 2 GPS-coordinates                          | <p>GPS-point 7 and 8<br>Provided before start</p>          | N/A                                                                                                     |

**TASK GUIDELINES:**

Step 1:

You are given the clear signal from the Chief Marshall to steer your vessel to GPS-point 7 of Task 3.2. This shall be done through Remote Control.

Step 2:

Once given the go-ahead from the Chief Marhsall, you must switch to Autonomous Mode, and your ASV may start its attempt at Task 3.2. Your turn starts when the ASV crosses the first gate.

Step 3:

Once observing the Otter vessel, your ASV shall signal the detection, and safely maneuver around the marker vessel.

Step 4:

Once you pass the final gate of the Task 3.1, your attempt finishes. Then your ASV shall go to GPS-point 8 and stay stationary there, waiting for go-ahead to proceed. You may switch to Remote Control if needed.

Step 5:

Once given the go-ahead, the ASV must be steered, in Remote Control, back to GPS-point 7, without crossing the course.&#x20;

Step 6:

When the Chief Marshall gives the go-ahead, you may steer the ASV safely back to the dock in Remote Control.

