Beginning from its first edition in 2013, the Singapore Autonomous Underwater Vehicle Challenge (SAUVC) has grown to become one of the largest underwater robotics competitions in the world. The competition is typically held at the Singapore Polytechnic (SP) swimming pool and sees participation from dozens of teams from around the world every year. In the 2019 event, the four-day long competition was structured with a practice round on the first day, a qualification round on the second day, the finals round on the third day and a series of talks and the prize distribution on the last day.

The SAUVC is made possible through the efforts of volunteers. Some of these volunteers are staff of the Acoustic Research Laboratory (ARL), where I was interning since January 2019. By February, the topic of the upcoming SAUVC began to dominate lunchtime conversations in the lab and it piqued my interest enough that I decided to become a volunteer for SAUVC 2019.

Day 1

SAUVC 2019 kicked off on March 8, 2019. Teams started rolling into SP’s event hall (aptly named “The Hall”) after 10am and had promptly started setting up their robots. During this time, I was able to gauge the difficulties faced by some of the teams in preparing their robots for the tasks that lay ahead.

Underwater robotics is quite challenging as compared to aerial/land robotics due to different factors including cost and logistics. Underwater robots use more expensive components than land and aerial robots such as rovers and quadcopters respectively. At SAUVC, most teams also said that in addition to facing challenges due to the cost of components for their robots,  another challenge they faced was to find an ideal place to test their robot underwater. Teams overcame these issues with innovative solutions. It was refreshing to see the variety of autonomous underwater vehicles (AUVs) that the teams had constructed. Of note was Team FEFU’s (Far Eastern Federal University, Russia) rectangular AUV and Team Hornet’s (NUS, Singapore) toroidal AUV.

The teams were allotted 15-minute time slots for using a secondary swimming pool (beside the main arena) to test their robots. I was assigned the role of “slotmaster” to manage the teams’ requests to book these slots. Due to the space constraints, each team could only use a section of the pool to practice in. Manning the whiteboard and directing teams to their respective sections became a busy affair in the middle of the day, when we had upto six teams using the pool at the same time! The day concluded with a debrief meeting in the evening. Even though I was exhausted after the day’s efforts, I was excited to see what the teams had to offer in the qualification round the next day.

Team FEFU’s AUV

Day 2

On the second day, the teams had to launch their AUVs in SP’s main swimming pool to autonomously swim through a gate in the middle of the pool. The top 15 teams in ascending order of runtime would get the chance to compete in the finals.

It is a trope known among the organizers that Murphy’s Law plagues every SAUVC, and this year was no different. Some teams had to deal with critical issues ranging from broken thrusters, malfunctioning cameras and even hull leaks just before their time slot. Despite this, many teams were able to successfully complete the task swiftly.

I also attended a workshop on Robot Operating System organized alongside SAUVC. In this workshop, Dr. Benjamin Ma, a senior lecturer from Nanyang Polytechnic, Singapore, spoke about his project to create a self-driving car from scratch. He spoke about his design decisions and provided an overview of the technologies he used to develop it.

Team Hornet’s AUV

It was a thoroughly educational talk and I enjoyed hearing Dr. Ma’s perspective on the future of autonomous vehicles in Singapore.

Following this, I spent some time interacting with the teams and learning about their experience with building their AUVs. Since one of the requirements of the competition was that the AUVs had to remain underwater without touching the pool’s floor at all times, perfecting depth control was essential. To accomplish this, most AUVs had numerous vertically mounted thrusters for providing the downward thrust required to maintain the AUV at the correct depth. Designing the control system for these robots was also challenging. This is because underwater odometry has to work accurately without the use of systems based on Global Navigation Satellite Systems (GNSS) such as GPS, which is widely used to localize other kinds of outdoor robots. Positioning systems based on inertial navigation systems (INS) tend to suffer from drift errors. So, the teams had to come up with innovative solutions to manage control and positioning.

Ryan Lee, an SAUVC 2019 volunteer, performs his slotmaster duties

The teams also spoke about their considerations for picking the optimal hardware and software platforms for completing the tasks. For instance, several teams used waterproof BlueRobotics thrusters and electronic speed controllers for the propulsion and control of their robots. On the software side, a computer with an Intel processor running ROS for managing sensors and actuators was the platform of choice.

Most students said they had been spending nearly all their free time to work on their robots for months before the competition. They also explained that being mentored by their seniors helped them develop the skills they needed to undertake these projects. Additionally, budget constraints led teams to implement innovative solutions such as using the brushless motors and propellers typically used in Radio-Controlled aircraft. One team even constructed their own water tank!

The day ended with the announcement of the 16 teams which had qualified for the finals. Team “Tech_SAS” from Telkom University, Indonesia came first in this round, giving them the last slot for the finals round on the following day.

Teams assemble in the “The Hall” for the safety briefing

Day 3

The final round of SAUVC 2019 was held on the third day of the competition. Teams were assigned slots in the pool in the reverse of their ranking in the qualification round to keep the competition more engaging throughout the day.

The tasks for finals included navigation, visual identification, acoustic localization and robotic manipulation. This was considerably more difficult than the qualification round and teams struggled with completing all of the tasks. It was also hard work for the volunteer scuba divers who had to retrieve and haul the AUVs back to the starting position for additional attempts.

I watched the progress of the teams on the TV set up near the side of the pool. Earlier in the day, some volunteers had set up underwater cameras for live-streaming video from multiple angles. The competition was intense and several teams were tied on the number of points. That said, by the end of the day, the top three teams were unequivocally clear.

Dr. Benjamin Ma’s Talk

Day 4

On the last day of SAUVC 2019, the event shifted from SP’s swimming pool to “The Hall”, a conference room in SP. There were many talks and panel discussions revolving around the topic of robotics, environmental conservation and underwater communications.

For me, the highlight was the opening talk by Liu Ren Jie. Ren Jie is a fourth year Electrical Engineering student at NUS and he is the Technical Head of Bumblebee Autonomous Systems, the underwater robotics team of NUS. He spoke about how the Bumblebee was formed and the story of how the team grew from strength to strength over the years. Bumblebee has a rigorous entry process which starts with Bumblebee members mentoring students in its SAUVC subsidiary team, “Team Hornet”. Ren Jie also brought for display the AUV that contributed to their victory at RobotX 2018. My takeaway from the talk was understanding the necessity of good leadership, team-building activities and student mentorship in running a multidisciplinary robotics team, as good technical skills are far more useful when they are disseminated among the entire team.

One of the divers at SAUVC, Dr. Mandar Chitre, retrieves Team Bubbles’ (SUTD) AUV

Over lunch, I learned about the curious design of SUTD’s AUV through their mentor Lum Shi En. The robot’s design was unique with a tricopter-like configuration of three of its five brushless RC airplane motors, which were tuned to prevent the AUV from spinning out of control. It also featured an innovative approach to electrical isolation between its components with an intra-vehicular Wi-Fi network for transmitting control signals between its onboard computers.

In the evening, the teams congregated at University Town, NUS for the prize distribution and Gala Dinner. “FEFU” (Far Eastern Federal University), “N2-AUV” (Bogor Agricultural University) and “Intelligent Marine Vehicle Team” (Northwestern Polytechnical University) won the first three prizes respectively.

This brought an end to a very memorable SAUVC.

Learning Experiences

Ren Jie (from NUS) presents Bumblebee’s story

Having been a member of my college’s robotics club for two years, SAUVC was an eye-opening experience and it showed me the skills that are required to build and assemble a complex robot:

1. Team building: Despite the limited time and scarce resources available to undergraduates, the participants managed to successfully build underwater robots which could perform complex tasks. They displayed creativity in leaps and bounds and the teams they formed were prime examples of what was possible with the right mentoring and guidance. Ren Jie’s talk on the final day underscored this point by saying that organizing group outings to improve morale and team spirit was almost as important as working on the project at hand.

2. Age is no barrier: It was fantastic to see younger teams, such as “The Phoenix” from Macau Pui Ching Middle School. “The Phoenix” consisted of school students who demonstrated programming and debugging skills far beyond their age. They went on to earn an impressive top ten finish in the qualification round on the second day.

3. Resourcefulness is invaluable: I also heard many inspirational stories of teams making it to the SAUVC despite the logistical difficulties of sourcing parts. Team Duburi from Bangladesh was one such success story which leveraged the power of social media to contact suppliers for components and other AUV teams around the world for advice. From their beginnings in 2017, they have gone on to become one of the largest robotics clubs of their college, BRACU.

For instance, due to a lack of suitable parts, they had to improvise with using quadcopter propellers with DC gear motors for propulsion. As these motors were not powerful enough to submerge their AUV, they had to adjust the balance of their AUV so that it could submerge. The team also built their own depth sensor with an air pressure sensor placed in a balloon, the interior pressure of which would increase with the depth of the AUV. Duburi has also expressed interest in making the underwater robotics simulator they developed for their internal testing freely available to all teams to use.

The teams’ excitement was palpable!

This is exactly the type of collaborative effort that the SAUVC aims to encourage.

1. Learning from the teams: Interacting with teams to understand how they developed their AUVs was an integral part of my experience. They gave me interesting technical information about their robots, the challenges they faced and how they tried multiple approaches before settling for a single one.

2. Talks and Panel Discussions: The talks during this SAUVC covered several recent developments in robotics and underwater vehicles. Prof. Marcello H. Ang’s talk on “Robotics in Our Daily Lives” covered fascinating ongoing projects at the Advanced Robotics Center, NUS. Richard Mills from Kongsberg also presented some of their latest products, including the self-maintaining Eelume AUV and a hydrogen fuel-cell powered ship, driven entirely by electricity. As someone who wishes to pursue a career in robotics, these talks helped me with building some perspective of what the future of marine robotics will hold.

3. Work can be fun: SAUVC also had an amazing social angle for me. The organizing committee used to meet for drinks at the end of each day of SAUVC and it was great fun to swap anecdotes with other volunteers for hours over beer. After a hectic day of organizing, it was a welcome change of pace and it helped keep all the volunteers energized till the end of the competition.

As an intern, I don’t think I could ask for more from my time here in Singapore and SAUVC was an important part of what has made my internship special.

SAUVC volunteer team at Beerfest, after Day 3 of SAUVC

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Contributors

Arnav Dhamija is currently pursuing a master’s degree in Robotics from the University of Pennsylvania. He interned at the Acoustic Research Lab, NUS for his undergraduate thesis in early 2019. His blog can be found at https://arnavdhamija.com/