KIKS 2013 Team Description Paper
Takaya Asakura, Ryu Goto, Naomichi Fujii, Hiroshi Nagata,
Kosuke Matsuoka, Tetsuya Sano, Masato Watanabe and Toko Sugiura
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/~sugi/RoboCup.html

Abstract. This paper is used to qualify as participation to the RoboCup 2013
small size league about team "KIKS". Our robots and systems are designed under
the RoboCup 2013 rules in order to participate in the RoboCup competition. The
major improvements in this year are the enhancement of the performance and robustness of wheels, electrical circuit and automatic control system. The overviewsof them are described
Keywords: RoboCup, small-size league, engineering education, global vision

1.

Introduction

In RoboCup world competition, our team has continuously participated since 2004.
We came in top 4 in Singapore and Istanbul, and in top 3 in Mexico last year. Since
we are aiming for higher place compared with last year, further improvements has
been done in this year.
One of the educations for creative minds of students is using the robot contest. We
have executed the robot contest in our college just like RoboCup junior every year. So,
main purpose of our participation to the RoboCup world competition is confirmationand evaluation of effect for creativity.
In last year, there was a problem that the travelling performance of robots was poor.
So, we redesigned a new wheel and improved the stability of the robots under travelling on the field. We also redesigned speed controller on the AI server. As the results,
response performance was better than that of last year.
The main topics of robot’s hardware developed for 2013 model are following terms,
・Improvement of the wheels
・Improvement of the electric circuit
・Improvement of the speed controller on the AI systemadfa, p. 1, 2013.
© Springer-Verlag Berlin Heidelberg 2013

2.

Hardware of the robot

Fig. 1 Overview of 2013 model
Table 1. Specification of robot for 2013 modelWeight2013 version
2.3kg

Main material

Aluminum alloy

Driving motor

maxon EC45flat (30watt)

Gear ratio

3.6 : 1

Wheel diameter

56mm

Number of solenoids

Straight kick: 1
Chip kick: 2

Straight kick power
Chip kick power

Ball speed of 8[m/s]
Max 3.0m away from robot under the condition of initial angle 40°

The overview of 2013 model is shown in Fig.1. The main configuration is basicallysame with the 2012 one. The wheel was only improved to achieve a stable travelling
performance. We redesigned the omnidirectional wheels again. In 2013 model, we
also use the brushless motors (maxon EC45 flat) as the driving motor, like many
teams. For the dribbling device, we use the brushless motor (maxon EC-max22)
again. Each robot has three solenoids. One is for straight kick and the other two arefor chip kick. The robot is able to shoot the ball at a speed of over 10[m/s], however,
it is down to 8[m/s] to keep to the regulations. The height and maximum projection on
adfa, p. 2, 2013.
© Springer-Verlag Berlin Heidelberg 2013

the ground for the robot is 148[mm] and 178[mm], respectively. And the maximum
percentage of ball coverage is 18%. The specification of the robot is summarized inTable 1.
2.1 Travelling performance of the wheel
Since 2011 competition, we have used the same brushless motors as many teams
do. But, there was a problem in previous wheel for performance of straight-runningstability of the robot. That is, our robots were not able to run straight stably under thecondition of max speed of 2ms-1 and acceleration of 3ms-2. Figure 2(a) shows theprevious wheel. There were two reasons why straight-running stability was bad. One
was that the small tires on wheel do not rotate smoothly. There were frictions between
small tire and the tire’s house. Another one was that the characteristic of friction tothe playing field for rubber small tire is not so good. It is made to occur the slippingof robot in play, because of use of O-rings with cross-section of circle with smaller
ground contact area. Thus, we redesigned new wheel to solve these problems. It waschanged to new design for the small tire as shown in Fig. 2(b).

(a) Previous wheel(b) Present wheel
Fig. 2 Previous wheel and new wheel
The new small tire is constructed with wider urethane material, metal pin andwashers as shown in Fig. 3(b). A previous wire shaft connected with all small one ischanged into each metal pin in new wheel. By using of two washers in small wheel’s
house the friction of small tire is decreased drastically. The urethane tire with crosssection of rectangular is effective to enhance the friction between wheel and playing
field.
As the results of wider width of small tire and more precise approximate circumference in new wheel, the robot can run smoothly and turn quickly. In addition, the resinmaterial as outside shell for wheel is easy for cutting work, and is effective for realization of high-speed rotation due to its light weight.

adfa, p. 3, 2013.
© Springer-Verlag Berlin Heidelberg 2013

urethane material
O-ringwashersmall pin(a)Previous small tire(b) Present small tire
Fig. 3 Component of small tire on wheel
Whole image of wheel is shown in Fig. 4. Because of an axle is only put on theback-board in new wheel, it was decreased the position gap of axle hole between thefront- and back-board. In addition, it is easy for assembling and maintenance by attaching the axle of every small tire on wheel independently.

wire-shaft(a)Previous wheel(b) Present wheel
Fig. 4 Whole image of wheel

adfa, p. 4, 2013.
© Springer-Verlag Berlin Heidelberg 2013

pin-shaft3.

Electrical design

The electronic circuit of KIKS is mostly same as last year. The new electronic circuits consist of two main boards shown in Fig. 5. They are main control unit and peripheral control unit. The main control unit includes the main CPU, power supply
circuit, wireless communication module, ball detecting circuit and dribbling motorcontroller. The peripheral control unit includes motor driver and voltage booster. Themajor changes are motor driver and voltage booster circuit.

Fig. 5 Construction of electrical circuit in the robot

adfa, p. 5, 2013.
© Springer-Verlag Berlin Heidelberg 2013

3.1 Main Control unit
This unit includes the circuit for detecting a ball, power supply circuit and wirelesscommunication module. The SH7262 (SH-2A series of Renesas) is used for a main
CPU that communicate each PIC for the peripheral controllers, such as BLDC controller, voltage booster circuit etc. The CPU runs 144MHz (345MIPS) and has 1MB
RAM. Its performance is enough to achieve the precise control of the robot.
3.2 Wireless communication system
We have used the Digi’s XBee module for communication system between hostPC and each robot. The wireless communication's frequency is 2.4GHz band. TheXBee module is able to communicate faster than conventional wireless module. It is
possible to communicate up to 115200bps.
3.3 BLDC motor driver
An each robot has four BLDC motor driver circuits for omnidirectional moving.
The MCU of motor driver is dsPIC30F4011. This circuit is added electrical current
sensing system. So, it is possible to control torque of each motor. 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 is used to boost up the voltage 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 4100μF
capacitor. The time to charge up to 200V from 16V is 2.46 seconds.

adfa, p. 6, 2013.
© Springer-Verlag Berlin Heidelberg 2013

4.

Software design

Our AI system is called the Strategy Information System(SIS). SIS design is mostly
same with last year. The overall software architecture is shown in Fig. 6. The software
consists of four threads, i.e., the Game Thread, Sender Thread, SSL-Vision ReceiverThread and Referee Box Receiver Thread. Moreover, the Game Thread includes somemodules.
Especially in 2013 version, we tried to improve speed controller on SIS. As the results, we achieved the max speed of 2.5ms-1 and max acceleration of 3.75ms-2. Thedetail is described below.

Fig. 6 Software architecture

4.1.

Improvement of speed controller

Up to now, it was examined by simple bang-bang control for speed control ofrobot. However, the method caused our control system to become unstable easily, andit was not robust for disturbance. Thus, we developed new speed controller for robots
on SIS. It has made it possible for running faster and more stable.

Unit 1
Targetposition P*Sliding
modecontrol

Unit 2

1
a* 𝑠Presentposition Pfor robot

Targetvelocity V*PDPID

Manipulated valuePresentvelocity Vfor robot

Fig. 7 New speed controller with two units
New controller has 2 units as shown in Fig. 7. The Unit 1 outputs the ideal motion
speed based on the robot’s position with considering of max acceleration andadfa, p. 7, 2013.
© Springer-Verlag Berlin Heidelberg 2013

convergence velocity V* to the target position P*. We applied tentatively sliding
mode control theory for speed of robot. As the result, it can easily control them. The
equation of sliding mode parameter σ and ideal acceleration 𝑎 ∗ are shown as follows,
σ = (𝑃 ∗ − 𝑃) + 𝐻𝑉 ∗(1a) ,𝑎(𝜎>0)𝑎 ∗ = { 𝑚𝑎𝑥(1b) ,−𝑎𝑚𝑎𝑥 ( 𝜎 < 0)
, where H is positive efficiency and used to decide convergence velocity.
3000

V* (H=2 amax=3000)

(a)

2500

Velocity V*(mm/s)

V* (H=4 amax=3000)
2000

1500
1000
500
00

1

23time(s)
3000

(b)

2500

Velocity(mm/s)

Robot's velocity V(mm/s)
2000
Target velocity V*(mm/s)
1500
1000
500
00

1

23time(s)Fig. 8 Time dependence of velocity for robot

The Unit 2 outputs the manipulated value to follow the robot’s velocity V to target
velocity V* getting from Unit 1. Since it has two-degree- of freedom control as shown
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in Fig. 7, it is robust against the disturbance. Figure 8 show the time dependence ofthe velocity until arriving to the target position. In Fig. 8(a), it is shown that the target
velocity V* is varied depending on the coefficient H of eq.(1a). Thus, it will be got
optimum performance under the condition of stable control loop by applying
appropriate parameter. In Fig. 8(b), it is shown that the agreement between robot's
velocity and target velocity is fairly good. That is, the velocity of robot will be able torespond within 100msec.

5. Conclusions
Our robots have been continuously improved in every year. As the results, thetravelling performance is getting better and robots are able to move more quickly thanlast year.
We hope that our robots will perform better in this coming competition.

adfa, p. 9, 2013.
© Springer-Verlag Berlin Heidelberg 2013