A proposal for a new small size robot league (New SSL)



                                                               June 18, 2008

                                            Small size robot league Volunteers

            Naruse, Murakami, Masutani,

Nagasaka, Fujii, Nakagawa,

Mitsunaga, Naito


An outline of the proposal

1.      New SSL league: Teams with small size humanoid robots up to 5 compete with each other under the global vision environment, instead of the conventional wheeled small size robots. The biggest difference from the other leagues is to use the global vision system. The technical growth of the current small size league suggests the necessity of change from wheeled robots to humanoid robots.


2.      The purpose of the new SSL is twofold: to study and develop the humanoid robot system using the global vision system, and to promote the AI research such as cooperative play among humanoid robots under the global vision system environment. We believe the global vision system gives us the shortest way to reach the 2050 goal.  


3.      Features from research view point:

3.1 Vision: From two dimensional recognition toward three dimensional recognition of the space, and from using markers towards not using markers: To solve these issues, 1) the real time restoration of the three dimensional information from two dimensional images and the real time correspondence problem should extensively have studied, 2) the vision system which recognizes three dimensional objects in real time is required, 3) three dimensional behavior recognition of the robot is also an important task.

 3.2 Humanoid skills: Since the global vision system makes it easy to realize the intelligent environment than the local vision system, AI studies for strategies, tactics and skills will be accelerated. In the studies, the ball-handling using the robot hands and head as well as the one using robot feet are included, i.e. adding to the conventional kick, a throw-in and header will be developed.

3.3 Intelligent Environment: The study to make the competition space be intelligent is necessary.


4.      Features from competition view point:

4.1 Robots: Small size humanoid robots are used. Two cases of the robots are 1) team’s original robots that conform to the technical standards and 2) off-the-shelf robots which the committee allowed to use (One-make robot or standard robot is encouraged in this context.).

4.2 Advanced global vision system: A distributed street-lamps viewing system is introduced instead of the conventional viewing system, since the over-field cameras are not good enough for the three dimensional recognition. Typically, 4 cameras or more are set around the field like street-lamps. For the beginning years, conventional viewing system is allowed.

4.3 Shared vision system: The shared vision system (including cameras) is provided by the committee, which gives each team the positions and orientations of the robots and the ball on the field. Team’s vision system (including cameras) is also allowed to use.


5. Expected effects of the New SSL:

5.1 To promote the R & D of the followings:

- mechanism and/or motion control of the humanoid robots,

- cooperative control among humanoid robots,

- three dimensional recognition/understanding of humanoid robots based on the image processing,

- intelligent environment (or intelligent robotic space)

5.2 To provide the empirical environment for the study of the intelligent environment,

5.3 To open up a new way for newcomers to join in.


I. Current situation and issues


1. Technical maturity of small size robot league

(1)   As for the soccer competition by the combination of wheel type robots and the conventional viewing system, completion is almost reached, and a new problem setting is needed for a future leap of research and development.


(2)   It becomes more and more difficult for the newcomers to participate in the competition since the technical level advances constantly and the developing cost increases.


(3)   On account of the substantial expansion of the field area, which results in the scale-up of the truss construction, the management cost for the competition increases.


2. Progress of the off-the-shelf humanoid robots

(1)   Recently, many small humanoid robots such as for hobby use are available in the market. Their prices decrease while their performance improves.


(2)   These robots have not the local vision system, but they move in a very flexible way. As a result, it becomes possible, by using these robots, to form the small humanoid robot teams that perform kicking by leg, throw-in by two arms, heading or saving actions by the goal keeper, which are quite similar to human playing.


3. Request toward the intelligent robotic space

For the cohabitation between human beings and robots, our society requests to control the robots in a high level and sophisticated way by optimizing the information through the visual sensor, the auditory sensor and RF tag incorporated in the environmental side.



II. Execution content


1.      Basic policy

(1)   A soccer play is organized among the teams of the small humanoid robots, replacing the wheel type robots.


(2)   Among the off-the-shelf robot hardware, the organizer shows some robot hardware which comply with technical standards to the participants.   


(3)   Remodeled and/or own-made robot teams are allowed to participate in the competition.


(4)   Participants’ intention is esteemed about the one-make competition by one type of hardware. If many participants hope the one-make competition, it will be allowed to take place.


(5) The distributed street-lamps viewing system with some cameras set around the field will be newly adopted. However, the conventional viewing system above the field is also used for the first few years.


(6) It is requested to establish as soon as possible the technology which enables to recognize the individual robots without team markers.


(7) The technical report of the software developed by the participant will be principally open to the other participants of the New SSL.


(8) The New SSL starts as a sub-league of the small size robot league. The current competition field is also used for the new SSL. For the beginning years, the half of the current field is used for the new SSL.


(9) Cooperation with the humanoid and 4-legged (or standard platform) leagues are actively promoted.


2. Robot Hardware

(1)   Shape: Humanoid robot with body, head, 2 arms and 2 legs.

(2)   Units of one team: not more than 5 units.

(3)   Height: Below 40 cm.

(4)   Weight: Below 3.0 kg.

(5)   Team marker: Sphere on the head of the robot. It will be removed in the future.

(6)   Standard Robot:

a)     The technical committee of the SSL chooses several kinds of robot hardware in the market place, and recommends them to the participants as standard robots.

( ex : KONDO KAGAKU Co., KHR-2HV @ 89,985 yen)

b) Own-made and remodeled robots can participate in the competition.

c) Participants’ intention is esteemed about the one-make competition with one type of hardware. If many participants hope the one-make competition, it will be allowed to take place.

(7)   Local vision system is allowed to mount.


3. Field

(1) Size: 4200mm x 3050mm, (A half field of the 2008 SSL field)

(2) Sufficient distance between lines and side walls.


4. Distributed Street-lamps Viewing System

(1) Number of Cameras:  4 units

(2) Position of Cameras:  1.5 m from ground around the field

(3) Standard Cameras:  Video Cameras for High Vision.

(4) Shared Vision System:

a) The shared vision system (including cameras) is provided by the committee, which gives the positions and orientations of the robots and the ball on the field to each team.

b) A team’s vision system (including cameras) is allowed to use.


5. Ball

 The orange tennis ball made of sponge used for kids’ tennis is adopted.


6. Radio communication

 Robots can communicate with computers outside of the field.


7. Instruction from the judge

(1)   Serial Communication Equipment (RS232C) or wired LAN is used to send the instruction of the referee to the computers of both teams.

(2)   In the future, robots are directed by referee’s voice.


8. Periods of Play

 Two 10 minutes periods with 10 minutes half time interval is adopted.


III. Expected effects


1.      Realistic approach toward the year 2050

(1)   As the current technology level is quite enough to start the basic level of soccer competition using the humanoid robots, the new SSL will make it possible to improve the combination of various R&D technologies together, and to achieve a standard that can compete with human teams by 2050.

(2)   Concretely speaking, the features that the humanoid robots have the shape of human beings enable to foster the research of action skills and behaviours such as a kick, header, throw-in and save.

(3)   This approach also contributes, towards the game with human team, to advance the research to avoid the dangerous play, such as collision, and analyze the strategies and tactics studied in the simulation league.


2.  Academic contribution

2.1 Mechanism and/or motion control of the humanoid robots

The global vision system brings a less-power-consuming light robot. It enables the high speed movement and various motion skills.

2.2 Cooperative control among humanoid robots

The local vision system limits the view and resolution, and it makes hard to recognize the global objects and to estimate the three dimensional motion. The global vision system promotes the study of the cooperative control, strategies and tactics for the humanoid robots.

2.3 Vision

(1)Real time three dimensional vision technology will be extensively developed.

(2)For the time being, the technology to recognize the individual robots without team markers will be developed.

2.4 Intelligent environment

(1)The distributed street-lamps viewing system will contribute to the development of the inevitable technology for the cohabitation between human teams and robot teams.

(2) In the future, the research that uses not only visual sensor but also aural sensor which will enable to process the voice of referee by the natural language analysis will be able to be studied.

(3)In addition, the distributed street-lamps viewing system can be used in the outdoor field as the automatic referee system.


3. Field cost reduction

The current expensive truss structure becomes unnecessary by using the distributed street-lamps viewing system. It brings the New SSL the savings of expenses and space.


4. Expanding the foot of robocuppers

To select the standard robot hardware and to provide the shared vision system will motivate new teams to enter the New SSL easily.

  It will also contribute to expand the foot of RoboCup.