pdftohtml_folder/2010_TDP

KIKS 2010 Team Description

Ryuhei Sato

, Takato Horii

, Kenji Inukai

, Shoma Mizutani

Kosei Baba

, Masato Watanabe

, Kazuaki Ito

and Toko Sugiura

Toyota National College of Technology,

Department of Electrical and Electronic engineering,

2-1 Eisei-cho, Toyota Aichi, 471-8525, Japan

sugi@toyota-ct.ac.jp

URL

：

http://www.ee.toyota-ct.ac.jp/~masa/2010/kiks2.htm

Abstract.

This paper is used to qualify as participation to the RoboCup 2010

small-size league (SSL) about team “KIKS”. Our robot is designed under the
Rules 2010 in order to participate in the SSL competition held in Singapore.
The overview for robots’ hardware of our team is described .

Keywords:

RoboCup, small-size league, brushless DC motor, motion control,

IR-sensor.

1 Introduction

Main purpose of our participation to the RoboCup world competition is

confirmation and evaluation of the results of the PBL (Project Based Learning)
experiments. We have educated the creative minds of students using the robot contest
held in our department of electrical and electronic engineering. For the RoboCup
world competition, our team has participated for six years since 2004, continuously.
We came in the top 8 in Graz 2009. Thus, since the aim will be higher, further
improvements are also needed in this year.

Recently, most of best top teams use the brushless DC motors. But we still use

brushed one (REmax 24). If we can replace to the blushless one, the robots must have
more torques and speeds. So, now we try to replace that and also review whole
mechanical design.

The main topics of developed system in 2010 are following term,

･

Enhancement of the performance of dribbling and kicking devices of the robot

in SSL.

･

Evaluation of the performance of ring-wheels and chip-kick devices.

･

Development of the circuit for DC blush less motors.

2 Development of new robots

2.1 The entire structure design.

At present time, we have changed three parts.

Replacement to brushless DC motors (Maxon EC45flat) from brushed one
(Maxon REmax24).

Redesign of chip-kick device.

Whole mechanical redesign taken into account of maintenance.

First, the motors which connect four ring-wheels were replaced to brushless motors

(Maxon EC45flat). They were used pinion gear with 20 teethes and internal gear with
72 teethes. That is, the reduction ratio is 1:3.6. The robot has not enough space to set
the gear box. So, we had to redesign to take account of narrow space between motor’s
axis and wheel’s that as shown in Fig. 1.

Fig. 1 Ring-wheel and internal gear

Second, the chip-kick devices were redesigned. The solenoid of chip-kick device

was under a normal kick device for previous design. But the solenoid often
electrically short out because of rubbing itself against floor. Thus, we replace the
solenoid of chip-kick device on that of the normal kick device as shown in Fig. 2. As
the results, we solved the problem mentioned above. Furthermore, because of large
space between chip-kick device’s bar and solenoid, it could get more kick power due
to the principle of leverage. In addition, the redesigning brought many advantages for
robot performance, e.g., more precise pass by kicking the center of a ball.

Fig. 2 Chip-kick device

Finally, whole mechanical structures were improved taken into account the

maintenance. Our robot had many problems in play because of components from a lot
of hand-made parts. At present, we replaced the base-plate to thick one and also made
the dents on the plate. The wheel units and kick devises were embedded in the plate as
shown in Fig. 3. As the results, the number of screws to fix on the body were able to
decrease because of the dents were worked effectively as shock-absorber against the
forces from various directions. If the robot is broken, it will be fixed up easier due to
the geometric design.

Fig. 3 Whole mechanical design

2.2 Evaluation of wheel structure.

Robots could run faster than last year by replacing the motors. As the results,

robots were required high performance for ring-wheels. So, we tried to improve the
ring-wheel’s structure. We had tested some types of ring-wheels as shown in Fig.
4(a)-(d). The (a) is the present type which has thin single tire with every thin unit
house. The (b) type has double small tires with every unit. The (c) and (d) types have
thick small tires which made normal rubber and silicone rubber tube, respectively.

(a) with single ring tires (b) with double ring tires

Fig. 4 Various type of the wheels used for evaluation.

Fig. 5 Average time to reach to 1[m/s] from static condition for the robot

(a)

(b)

(c)

(d)

Fig. 6 Average speed of the robot on the same condition

The experimental results of their performance are shown in Fig. 5-Fig. 6. Figure 5

shows the average time to reach to 1[m/s] from static condition. Figure 6 shows the
average speed on the same condition. Summarizing the results of our analysis, the (a)
type showed the most stable and best performance. The reason why the (a) type
showed the better results than the other types is not clear. It might be depended on the
number of unit houses. Anyway, we decided to use (a) type.

2.3 Chip-kick device structure

We tried to improve the chip-kick device to investigate the relation between the

length of rotation axis and angle within the limits of the space. By determining the
length R and angle

, respectively as shown in Fig. 7, we have measured a range of

ball when the R and

were changed. The result shows that a range of ball is strongly

depend on the

as shown in Fig. 8. On the other hand, the R is shown enough to have

only a few cm. Thus, we decided tentatively that the R is 25mm and the

is 60°. A

kicked ball reaches a height of approximately 600mm. That actual performance is
shown in Fig. 9.

Fig. 7 Length of rotation axis R and angle

of the chip kick device

(a)

(b)

(c)

(d)

Fig. 8

Experimental results of chip-kick device

Ball

25mm

60°

45°

Ball

25°

Ball

~600mm

~2000mm

Fig. 9 Specification and performance of actual chip-kick device

2.4 Dribbling device structure

In previous robot, we have used the RE-max17 motor for the dribbling devices.

But the motor did not have good enough performance for pass and shoot. So we tried
to change that motor into RE-max24. The motor’s power has increased from 4W to
10W. In addition, we just changed the dribble devices. Table I shows the performance
of new dribbling device. The previous and new dribbling devices are also shown
in Fig. 10.

Table I. Characterizations of new and previous motor.

Element

＼

Motor

New(Re-max 24)

Previous(Re-max 17)

Power

10 Watt

4 Watt

Diameter of Roller

~15mm

~13mm

Rotation

Frequency(Roller)

8800rpm 3900

rpm

(a) Previous dribbling device (CAD image) (b) New dribbling device (CAD image)

Fig. 10 Previous and new dribbler device

2.5 Detecting device for a ball

Up to now, the IR-Sensor was only used to find a ball in our robot. So, we attached

a new another IR-Sensor to check the position of the ball, and to enhance the
performance of catching the ball. As the result, the robot came to check the difference

of the position between the ball and robot, and obtained the good performance for
catching the ball. Attached new IR-Sensor is shown in Fig. 11.

(a) IR-sensor (b) Body with IR-sensor

Fig. 11 Detecting device (IR-sensor) for a ball

2.5 Electronic circuit for brushless DC motor.

We decided to use brushless DC motor because it is becoming one of the standard

equipment of the robots among the best teams in SSL. We replaced the motor to
Maxon EC 45 flat from Maxon RE-max 24. The motor is popular in the best team.
The motor’s power is more than six times compared with conventional RE-max24.
Therefore, the gear ratio could change from 8:60 to 20:72. As the result, the machine
was able to run more than 1.5 times faster than previous one.

There are two sensors in the motor. That is, the encoder and the hall sensor built in

the motor. E4P made by US DIGITAL was chosen as the encoder. Since its resolution
is 1440 pulse per revolution, it came to control easier in detail.

The Microchip dsPIC30F4012 was used for each motor’s control. The PICs were

connected to the motor through FET drive circuit. Each PIC was commanded by
SH2-7144 of Main MPU.

(a) Brushless Motor (b)Encoder

Fig. 12 Brushless motor and encoder

(a) FET circuit (b) Control circuit

Fig. 13 (a) FET circuit for motor drive unit and (b) its control circuit

3 Conclusions

We have improved the robots for SSL as well as last year. The performance of our

robot is getting high over the year. Most of devices are hand made by students. Thus,
the cost performance is very high in fact.

We hope that our robots will perform better in this coming competition than that of

last year. We will have a plan to join such competitions continuously in the future.

References

1. Touko SUGIURA, Masato WATANABE and Kazuaki ITO: Practice of Creative Education

Taken into Account the Continuous Participation to the RoboCup Small Size League and
World Competition, Journal of Education in the Colleges of Technology,

(2009) 345. [in

Japanese]