KIKS 2011 Team Description
Hisayoshi Hattori1, Kenji Inukai1, Yasuyuki Iwauchi1, Shota Zenji1,Shoma Mizutani1, Masato Watanabe1, Kazuaki Ito1 and Toko Sugiura1
Toyota National College of Technology,
Department of Electrical and Electronic engineering,
2-1 Eisei-cho, Toyota Aichi, 471-8525, Japansugi@toyota-ct.ac.jp
URL: http://www.ee.toyota-ct.ac.jp/~masa/2011/kiks2.htm

Abstract. This paper is used to qualify as participation to the RoboCup 2011
small-size league (SSL) about team “KIKS”. Our robots and system aredesigned under the RoboCup 2011 rules in order to participate in the RoboCup
competition held in Istanbul. The major improvements in this year are theenhancement of the performance of dribble device, changing the structure of theAI system and renewal of the circuit. The overview of there is described.
Keywords: RoboCup, small-size league, brushless DC motor, IR-sensor.

1Introduction

Main purpose of our participation to the RoboCup world competition is confirmationand evaluation of the results of the PBL (Project Based Learning) experiments. The
creative minds of students are educated using the robot contest held in department ofelectrical and electronic engineering. For the RoboCup world competition, our teamhas continuously participated for seven years since 2004. We came in the top 4 inSingapore 2010. Thus, since the aim will be higher, further improvements are alsoneeded in this year.
Our robot's performance improved by replacing to brushless DC (BLDC) motor atlast year. But, we found the problems for durability through the competition. The
dribble device is also in the similar poor condition. So, we reviewed wholemechanical design and tried to replace to BLDC motor for the dribbling device.
The main topics of developed system in 2011 are following terms,
・Improvement of the structure of strategy system.
・Development of the circuit for BLDC motors.
・Development of the circuit for Digi’s XBee wireless communication.

2

Hardware of the robot
In driving motor we use the brushless motors (maxon EC45 flat) with acustom back-extended shaft for useful to attach encoder, based on thereference [1]. They are used pinion gear with 20 teeth and internal gear with 72
teeth. That is, the reduction ratio is 1:3.6. Each robot is equipped with threesolenoids. One is for straight kick and the rest two's are for the chip kick.
These solenoids are driven by a 200[V] chargeable capacitor. Therefore, therobot will be able to shoot the ball at a speed of 10[m/s]. Moreover, the robot
can also kick the ball to the position of 3[m] away from the robot by using thechip-kick device.
The specification of the robot is shown in Table 1. The detail is described infollowing sections.
Table 1. Specification of the 2011 robot

WeightMaterialDriving motor
Gear ratio
Wheel diameterNumber. of solenoids
Straight kick power
Chip kick power

2011
2.3kg
Aluminum alloy
Maxon EC45 flat(30Watt)
3.6:1
56mm
Straight kick:1
Chip kick:2
Ball speed of 10m/s
3.0m away from robot

At present, we are doing the minor change of the robot of 2010 model focusing
attention on the following points.
1. Changing the motor used in Dribbling device and mechanisms.
2. Redesign of wheel unit.
3. Improvement of mounting arrangement of IR-sensor.

2.1

Improvement of dribbling device

Fig. 1 New dribbling device (CAD image)Fig. 2 Dribbling device of 2010 model (CAD image)

Figure 1 and 2 shows the dribbling device of 2011 and 2010 model, respectively.
The dribble device of 2010 model had stronger retentive force compared with oldmachine. That mechanism, however, was not structured to effectively receive andabsorb with the strong shock of the ball. Therefore, the gears and the structure weredamaged by the impacts. In addition, the power of the dribbling motor (Maxon REmax24) was not enough to give rise to the strong backspin of the ball for the backpass. Thus, we changed the motor to new one (Maxon EC-max22). As the results in2011 model, the rotational velocity of the dribble rollers was achieved approximately
three times compared with old model. And the gear would not be broken by using theimprovement of the shock-absorbing mechanism. The difference of the dribble
device's performance is summarized in Table 2.
Table 2 Comparison between new and previous dribble devices' characterization

Dribbling motor
PowerNew(2011)
Maxon EC-max22
25WattPrevious(2010)
Maxon RE-max24
11WattNominal speed

9820rpm

5870rpm

Nominal torqueGear ratio

22.9mNm
1:1.3

12.4mNm0.77:1

2.2

Changes in tire unit

Fig. 3 Previous tire unit (CAD image)

A tire unit in 2010 is shown in Fig. 3. To assemble the robot in the structure of Fig.
3, it is necessary to bend the encoder cable. The encoder is only fixed by adhesivetape. So, when the encoder cable was pulled by someone or somewhat accidents, theencoder was often come off. Thus, we changed the structure of the unit to solve thisproblem as shown in Fig. 4. In this structure, since the cable may not be pulled, theprobability of coming off of the encoder will be lower. Moreover, we changed theencoder which is able to fix with the screws in order to treat easily for overhaul. Inaddition, this unit is constructed with the popular spacer on sale. Thus, it is very good
to using for maintenance.

Fig. 4 New tire unit (CAD image)2.3

Improvement of sensor to find a ball←sensorFig. 5 Previous sensor units (CAD image)sensorFig. 6 New sensor unit (CAD image)The sensor of 2010 model was fixed as sandwiching by two plates as shown in
Fig.5. This structure, however, would slip off the sensor when the sensor was givenby a strong impact. So, the new sensor was mounted on the circuit board in order to
fix rigidly as shown in Fig. 6. Furthermore, the sensor is covered with the duralumin
for protection.

3Electrical design of new circuit

The new electronic circuits in 2011 model consist of two main boards. They aremain control unit and peripheral control unit shown in Fig. 7, respectively. The main
control unit includes the main CPU, power supply circuit, wireless communication
module, ball detecting circuit and dribbling motor controller. The peripheral control
unit includes BLDC controller and voltage booster.

Fig. 7 Construction of circuit in the new robot

3.1

Main Control unit

We have developed new main control unit. This unit includes the circuit for
detecting a ball, power supply circuit and wireless communication module. TheSH7262 (SH-2A series of Renesas) is used for a main CPU that communicate each
PIC to the peripheral controllers, such as BLDC controller, voltage booster circuit etc.
The CPU runs 144MHz (345MIPS) and has 1MB RAM. Its performance is enough toachieve the precise control of the robot.

3.2Wireless communication system

We have used the Digi’s XBee module for communication system between host PC
and each robot. The wireless communication frequency is 2.4GHz band. The XBeemodule is able to communicate faster than conventional wireless module. It is
possible to communicate up to 115200bps. Up to now, the communication speed was
19200bps. So since we will be able to send more information to the robot, it ispossible to develop more advanced controller.

3.3

BLDC controller circuit

An each robot has four BLDC control circuits for omnidirectional mobile. The MCU
of BLDC controller is dsPIC30F4012. Three phase PWM module and Quadrature
Encoder Interface for motor control in MCU are very useful for development ofBLDC controller. The motor speed of the robot is controlled by PI speed control in
MCU. This circuit is also used for dribbling motor controller.

3.4

Voltage booster circuit

The DC-DC converter to boost up the voltage is used for the solenoid. The input
voltage of 16V is converted to 200V output. This chopper circuit is controlled by PIC
in each robot. In the kicking device, the output voltage of 200V is charged in 4100uF
capacitor. The time to charge up to 200V from 16V is 5 seconds.

4Improvement of strategy system

Strategy system was also improved. The architecture of new strategy system isillustrated in Fig. 8. The strategy system consists of four modules called "Situation
Analysis", "Strategy", "Formation" and "Action".

Fig. 8 Construction of strategy system

4.1

Situation Analysis moduleThis module is located at top level in strategy system. This module plays the roleof analysis about the game situation from both position of the ball and robots on thefield, and generation of the trial instruction command.
4.2

Strategy moduleThis module is located at below level of Situation Analysis module. The role ofthis module is to select the optimal next Formation module from result of analyzing.
For example, when the result of analysis is “Indirect Free Kick of Own team”, theStrategy module will select the "Indirect Kick Formation module". On the other hand,when the result of analysis is “Need to Defense”, the Strategy module will select the"Defense Formation module". Since the Strategy module has many strategy patterns,
it will be able to select the optimal Strategy module corresponding to the gamesituation.

4.3

Formation moduleThis module is located at below level of Strategy module. This module plays therole of the decision of the next Action module which should be performed by eachrobot.
4.4

Action moduleThis module is located at the bottom level in strategy system. The role of thismodule is to command the specific operations to each robot. The "Direct Shoot
Action" for instance, is command to kick a ball for the robot. Alternatively, the "WallDefense Action" means moving the robot to the position to defend the goal.

5Conclusions

We have improved the robots of SSL as well as last year. As the results, someproblems found in last year were solved and the performance of the robot wasachieved best among the recent years.
We hope that our robot will be doing the best in coming world competition.

References[1] Piyamate et al. Skuba 2010 Extended Team Description. In: Proceedings ofRoboCup 2010.