<commit_before>---
layout: post
title: Collision avoidance for ASVs using the Dynamic window approach
---
Autonomous technology is spreading across numerous applications at an unprecedented pace. Amongst others, the DARPA Grand Challenge for autonomous ground vehicles has given an indication of what is possible to achieve using state-of-the-art sensors in combination with cleverly designed autonomous algorithms. We believe the increasing use of autonomy in vehicle systems eventually will propagate to the maritime industry and that we will see an increasing level of autonomy on ships in order to increase safety, and to reduce operational costs, emissions and impacts from human-induced errors.

The Dynamic Window (DW) approach to collision avoidance (COLAV) was introduced for robots in the late 1990s. A series of modifications to the algorithm are proposed, and in particular the algorithm has been adapted for use with both autonomous underwater vehicles (AUVs) and autonomous surface vehicles (ASVs). This combined project and master thesis proposal focuses on further development of the DW algorithm applied to ASVs. The plan is that the DW algorithm is to be included in a multi-layer (hybrid) COLAV architecture, and act as a “last line of defense” in avoiding collision. It should also be investigated if the algorithm is suited to partly of fully comply with the international regulations for preventing collisions at sea (COLREGS).

As mentioned, this proposal is intended as a combined project and master thesis during the autumn of 2016 and spring of 2017. The candidate will be associated with the AUTOSEA project, which is a collaborative research project between NTNU, DNV GL, Kongsberg Maritime and Maritime Robotics, focused on achieving world-leading competence and knowledge in the design and verification of methods and systems for sensor fusion and COLAV for ASVs. The project has access to supervision and physical test platforms through our industry partners.

| <img src="{{site.url}}/assets/mariner.jpg" width="300"> | | <img src="{{site.url}}/assets/telemetron4a.jpg" width="300"> |
|:---:| |:---:|
| USV Mariner, an unmanned surface vehicle | | MR Telemetron, a dual-use surface vessel |

## Proposed Tasks
**For the project assignment (autumn 2016), the following tasks are proposed:**

1. Do a literature review on reactive COLAV, focusing especially on the DW approach to COLAV. The literature review should also include COLREGS.
2. Implement a simulation framework with both moving and static obstacles in 3 DOF.
3. Get familiar with the DW algorithm through simulations.

**For the master thesis (spring 2017), the following tasks are proposed:**

1. Further develop the DW algorithm for use with ASVs:
    1. Investigate different ways to sample the search space.
    2. Is it possible (and desirable) to compute trajectories offline?
    3. Let paths be defined by multiple (2 or more) velocity pairs. How does this affect the computational load and performance?
2. Modify the DW algorithm to work as a trajectory tracker, and investigate possible interfaces between deliberate (high-level) COLAV algorithms and the DW algorithm in hybrid architectures. This work may be supported by another MSc-candidate working on cascaded nonlinear feedback control of ships.
3. Is the DW algorithm suited to partly or fully handle COLREGS?
4. Based on the simulation results, full-scale tests may be possible.

## Supervisors 
Main supervisor: [<NAME>](http://www.ntnu.no/ansatte/morten.breivik). <br />
Co-supervisors: [<NAME>](http://www.ntnu.no/ansatte/boerikse)<commit_msg>Again<commit_after>---
layout: post
title: Collision avoidance for ASVs using the Dynamic window approach
---
Autonomous technology is spreading across numerous applications at an unprecedented pace. Amongst others, the DARPA Grand Challenge for autonomous ground vehicles has given an indication of what is possible to achieve using state-of-the-art sensors in combination with cleverly designed autonomous algorithms. We believe the increasing use of autonomy in vehicle systems eventually will propagate to the maritime industry and that we will see an increasing level of autonomy on ships in order to increase safety, and to reduce operational costs, emissions and impacts from human-induced errors.

The Dynamic Window (DW) approach to collision avoidance (COLAV) was introduced for robots in the late 1990s. A series of modifications to the algorithm are proposed, and in particular the algorithm has been adapted for use with both autonomous underwater vehicles (AUVs) and autonomous surface vehicles (ASVs). This combined project and master thesis proposal focuses on further development of the DW algorithm applied to ASVs. The plan is that the DW algorithm is to be included in a multi-layer (hybrid) COLAV architecture, and act as a “last line of defense” in avoiding collision. It should also be investigated if the algorithm is suited to partly of fully comply with the international regulations for preventing collisions at sea (COLREGS).

As mentioned, this proposal is intended as a combined project and master thesis during the autumn of 2016 and spring of 2017. The candidate will be associated with the AUTOSEA project, which is a collaborative research project between NTNU, DNV GL, Kongsberg Maritime and Maritime Robotics, focused on achieving world-leading competence and knowledge in the design and verification of methods and systems for sensor fusion and COLAV for ASVs. The project has access to supervision and physical test platforms through our industry partners.

| <img src="{{site.url}}/assets/mariner.jpg" width="450"> | | <img src="{{site.url}}/assets/telemetron4a.jpg" width="450"> |
|:---:| |:---:|
| USV Mariner, an unmanned surface vehicle | | MR Telemetron, a dual-use surface vessel |

## Proposed Tasks
**For the project assignment (autumn 2016), the following tasks are proposed:**

1. Do a literature review on reactive COLAV, focusing especially on the DW approach to COLAV. The literature review should also include COLREGS.
2. Implement a simulation framework with both moving and static obstacles in 3 DOF.
3. Get familiar with the DW algorithm through simulations.

**For the master thesis (spring 2017), the following tasks are proposed:**

1. Further develop the DW algorithm for use with ASVs:
    1. Investigate different ways to sample the search space.
    2. Is it possible (and desirable) to compute trajectories offline?
    3. Let paths be defined by multiple (2 or more) velocity pairs. How does this affect the computational load and performance?
2. Modify the DW algorithm to work as a trajectory tracker, and investigate possible interfaces between deliberate (high-level) COLAV algorithms and the DW algorithm in hybrid architectures. This work may be supported by another MSc-candidate working on cascaded nonlinear feedback control of ships.
3. Is the DW algorithm suited to partly or fully handle COLREGS?
4. Based on the simulation results, full-scale tests may be possible.

## Supervisors 
Main supervisor: [<NAME>](http://www.ntnu.no/ansatte/morten.breivik). <br />
Co-supervisors: [<NAME>](http://www.ntnu.no/ansatte/boerikse)
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