Takumi Matsuda, The University of Tokyo, IEEE OES Japan Chapter
Underwater Robot Convention 2019 was held in JAMSTEC (Japan Agency for Marine-Earth Science and Technology) from August 23rd to August 25th, 2019 [1, 2]. This event in JAMSTEC was held from 2010 and it is 10th time this year. More than 200 researchers, engineers, students, and visitors from institutions across the country participated in the convention. The convention has three sections: a free style section, an AI challenge section, and a junior section.
The Underwater Robot Convention by the NPO Japan Underwater Robot Network  can strengthen research cooperation between underwater robot researchers in Japan and neighboring Asian countries, and develop next-generation underwater robot researchers. The convention has been introduced in this newsletter several times in the past [4-6]. This event usually involves about 20 teams. Most of them are researchers and students who are interested in underwater robotics. Each team brings the latest underwater robot that realizes the latest ideas and innovations that occur in the laboratory. As a result, this is a unique and wonderful opportunity to discuss and exchange the latest ideas and innovations in a friendly and competitive atmosphere.
Free Style Section
Each team develops a robot based on unique ideas and participates in the convention. They compete for the originality of their robots. In addition to the development background, the practicality and originality of their robot is evaluated. Each team competes for the total score of weight points, presentation points, and competition points. The competition points are determined by performing a 4-minute performance twice.
AI Challenge Section
This section is held for the first time this year. Each team implements their developed algorithms on their robot provided in advance or developed on their own, and compete for their processing capabilities. They compete for the sum of presentation points and competition points. A training seminar is held in this section to provide knowledge for development.
The junior section is a competition for junior high school students, high school students and technical college students. Underwater robot kits are provided free of charge to the teams entered one month before the tournament. Participants assemble and modify them before the competition. The task in this competition is collecting cans. Each team is evaluated based on how many cans can be collected within the limited time. Higher scores can be expected if cans can be collected from a field simulating seaweed.
Prior to the competition, the seminar was held. The objective of this seminar is to encourage the information exchange and strengthen the technical expertise of the whole community. More than 100 researchers, engineers, and students attended the seminar this year. There were lectures about the investigation of shipwrecks using underwater robot technology, about reproducing extinct creatures as robots, and about Team KUROSHIO which participated in the Shell Ocean Discovery XPRIZE [7, 8].
In the free style section, there were various kinds of robots, such as robots developed based on a paleoorganism and Gokai, a multicopter, which moves underwater and in air, and a helicopter type robot. Each team developed the robot based on their unique ideas. Each robot is introduced in the following sections.
OYG-YKT_3 (Keio Shonan Fujisawa Senior High School)
The series of this robot was developed six years ago to investigate the ecosystem of the Gulliver Pond in the school. OYG-YKT_3 is the third edition. Cameras are equipped for the investigation of the environment. This pond is very shallow (depth is 1m), so the robot must be low and flat. A PVC pipe and an acrylic board are used for the robot. Four vertical and horizontal thrusters are installed. Arduino and Raspberry Pi are used for control.
Drepana First Edition (Tokyo Tech High School of Science and Technology)
This robot is an underwater glider that was developed based on a paleoorganism called Drepanaspis. The robot can perform several actions: diving, surfacing, and swimming. It swims from the starting point to the destination using the GPS position and then dives for an arbitrary time. The purpose is to collect water temperature data at regular intervals using a temperature sensor in the destination area. After completing collection of data, the robot surfaces and returns to the starting point.
The robot was made by PP board. Inside the robot, Arduino and GPS modules used for control are installed. Waterproof servo motors are fixed to the robot. Systems for adjusting buoyancy and moving the tail fin are installed.
Moonswim III (Shinshu University)
This robot was developed by focusing on Gokai. It has a fin that correspond to the warts. By changing the angle of the fin, it can swim in all directions and move back as if it is moving forward, so it was named as Moonswim. After that, several generations were developed. Moonswim II can move left and right fins actively, and Moonswim III has improved actuators and control system.
MizudeppoTaro (Tokyo Institute of Technology)
This robot can recognize moving objects and knocks them out with a water gun. It recognizes the surroundings by a phased array sonar using multiple ultrasonic sensors. In addition, the sonar recognizes the signal from the fixed marker placed on the ground, so that the distance and direction from the fixed marker are determined, and then self-position estimation can be performed. This phased array is also assumed to be used for underwater terrain mapping and object recognition.
gen4 (Tokyo Institute of Technology)
gen4 has 4 thrusters which consist of one surge thruster, one heave thruster, and 2 sway thrusters. Pressure hulls for thrusters and computers are separated. It is designed to launch a handset. The robot is covered with a plastic plate to reduce the water resistance so that it can move forward faster. The thruster for forward movement is being improved so that large power can be used.
Ginjiro (Keio University)
Ginjiro is an autonomous underwater robot that is aimed to investigate the oceans of the extraterrestrial bodies. The robot takes images of the seabed over a wide area after being transported to the target celestial body by a rocket. And then, it transmits the information to the station of the earth. In the future, a seafloor map can be obtained by analyzing the video. Besides, water temperature, components contained in the water can be measured and mapped. The robot has a pressure-hull that contains the control unit. Camera unit is located in the front. It has four thrusters that consist of two horizontal thrusters and two heave thrusters for navigation.
Stingray (Tokyo Metropolitan College of Industrial Technology)
This robot can be controlled in surge and yaw directions by two horizontal thrusters. Heave, roll and pitch control is performed by three vertical thrusters. A wide variety of equipment can be attached to the 20 mm rail at the bottom of the robot. Attachments can be selected depending on the application. Since the robot is operated by tether cable, stable operation can be realized.
HSK-19 (Hakodate Fisheries High School)
HSK-19 is an ROV equipped with both horizontal and vertical thrusters. The thruster uses a kerosene pump motor. Power is supplied from the battery on the land side by wired cable. In addition to the power cable, a video output cable is provided. The action cam is used for video output and recording. Although the heavy materials, such as aluminum plates, are used in the robot structure, this team still tries to reduce the design weight.
DTRU (Tokushima University)
Diving Tilt Rotor UAV (DTRU) is an underwater and aerial multicopter, which was developed based on a 4-shot tiltrotor multicopter. A radio wave of 72MHz is used for control. It can dive by its thrusters and move underwater by tilting its thruster. It succeeded in diving 3m depth in the pool. It has also navigated successfully in rivers.
Marine Da Vinci Copter (National Institute of Technology (KOSEN), Oyama College)
This robot is developed based on a helicopter devised by Leonardo da Vinci. An air screw (hereinafter referred to as a Da Vinci screw) is used for the propeller of this helicopter. This helicopter cannot fly in the air, but when operated in water, the helicopter can move due to the high viscosity of the fluid and buoyancy. This robot can realize a Da Vinci helicopter that flies elegantly underwater.
There were many robots based on unique ideas in this year’s competition. Among them, Moonswim III from Shinshu University won the first prize. This team demonstrated that their robot can change the moving direction by changing the angle of the fin.
In the AI challenge section, the robot recognizes and breaks red, yellow, and blue balloons deployed in the water. Scores vary by color, with 30 points for red, 20 points for yellow, and 10 points for blue. A method of recognizing by masking and a method of recognizing using machine learning were adopted. In addition, each team showed its own uniqueness, such as focusing on a specific color and crushing balloons from above. The robot named jellyfish from Toyohashi University of Technology won the first prize this year. This team succeeded in breaking five red balloons.
In the junior section, each team competes the performance of their robots and skills. Each team developed the robot before the convention using a kit provided from the committee. On the first day, they conducted an operation test of their robots. On the second day, they competed to control the robot, pick up empty cans on the pool floor, and competed their ability to operate the robot.
The scene of the free style section. The left: Moonswim III from Shinshu University (first prize). The right: Marine Da Vinci Copter from National Institute of Technology, Oyama College (second prize).
The scene of the AI challenge section. The left: the robot tried to break the yellow balloon using a machine learning approach. The right: the robot from Toyohashi University of Technology which won the first prize.
The awards ceremony. Top three or two teams in each section were awarded. The top left: Shinshu University, which won the first prize in the free style section. The top right: Toyohashi University of Technology, which won the first prize in the AI challenge section. The bottom left: Shibaura Institute of Technology Senior High School, which won the first prize in the junior section. Special award was also given to one team shown in the bottom right.
In all the sections, many teams were confronted with difficulty of hardware trouble such as thrusters, cameras, water leak and so on. The convention provided an excellent opportunity for all participants to show and share the latest technique in the field of underwater robots. After the convention, they share each idea and leave with a sense of satisfaction. Human networks made through the convention will lead to the development in underwater techniques and the encouragement of the next generation of underwater robotics researchers.
For more details about the activity of the Underwater Robot Convention, NPO Japan Underwater Robot Network, visit the links shown in the references.
- Underwater Robot Convention in JAMSTEC 2019, jam19.underwaterrobonet.org/
- JAMSTEC, www.jamstec.go.jp/e/
- NPO Japan Underwater Robot Network, underwaterrobonet.org/
- Matsuda, K. Asakawa, T. Maki, Underwater Robot Convention in Japan, IEEE OES Newsletter, Vol. 4, No. 4, pp.14-17, 2015.12
- Horimoto, T. Nishimura, T. Matsuda, AUV “Minty Roll” and results of “Underwater Robot Convention 2017 in JAMSTEC”, IEEE OES Beacon Newsletter, Vol. 6, No. 4, pp. 77-79, 2017.12
- Yamagata, T. Maki, Underwater Robot Convention in JAMSTEC 2018 — from an Educational Perspective, IEEE OES Beacon Newsletter, Vol. 7, No. 4, pp. 68-72, 2018.12
- Team KUROSHIO, team-kuroshio.jp/
- Shell Ocean Discovery XPRIZE, www.xprize.org/prizes/ocean-discovery