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Owaribito-CU 2010 Team Description

Yasunori NAGASAKA, Morihiko SAEKI, Takuya SOGO,

Shoichi SHIBATA, Hironobu FUJIYOSHI, Takashi FUJII,

Yoshiyuki TANAKA, Masafumi JYOUO, Takumi ADACHI,

Masaki ITO, Kazuhiro SUZUKI, Kazuo TAUCHI,

Chikara INUKAI, and Alfred EBADE EFOSA

Faculty of Engineering, Chubu University, Japan

any@nn.solan.chubu.ac.jp

Owaribito-CU 2010 Robots

We have improved some points of our soccer robots for RoboCup 2010. These
robots are equipped with a holding device and a kicking device. Our kicking
device now has a chip shot function. Four omniwheels are used for the driving
mechanism; they aid in realizing omnidirectional motion. The hardware speciﬁ-
cations are listed in Table 1. The robot is shown in Figure 1.

Table 1.

Hardware speciﬁcations of Owaribito-CU 2010 robots

Height

141 mm

Maximum diameter of projection

178 mm

Maximum ball coverage

19 %

Gross weight

2200 g

Body frame material

polycarbonate

Main microcomputer

H8/3052F

Motor control

dsPIC30F4012

Wireless communication

Futaba FRH-SD07T

Motor

Maxon Re-max 21

Power supply for driving

GP2300Ni-MH AA size

Capacitor for kicking devices

400 V, 390

Power supply for kicking devices

Lithium ion 3.7 V, 2000 mA

From among the research that was worked on this year, this text describes

the improvement of the kick device mechanism. It also involves the improvement
of the circuit board, ID setting and power supply function.

Improvement of Kick Device

Figure 2 and Table 2 shows the external and the detailed data of an existing
column type of kick device. The driving source of this kick device is a solenoid

Fig. 1.

Owaribito-CU 2010 robot

as well as most other robots of Robocup small-size robot league. The following
were achieved in the last research work.

–

The shot speed was adjusted to 10m/s

–

The development of a chip kick device.

The aim of this project is the miniaturization of the kick device, without any

reduction in the shot speed. Figure 2 shows the Column type kick device.

Fig. 2.

Column type kick device

2.1

The Problems of Kick Device and Solutions

The problems of the current type of kick device are outlined below:

Table 2.

Speciﬁcations of column type kick device

Stroke length[mm]

40.0

Diameter of enameled wire[mm] 0.6
Number of coil layers

Weight of solenoid[g]

175

Weight of head and core[g]

75.7

Average speed of ball[m/s]

9.8

–

We use the column type solenoid to use the ﬂux of the magnetic induction
eﬃciently. As a result when installing the kick device in the robot, wasteful
space is being developed.

–

Because the core is a column type, it is necessary to install a head that can
hit the ball.

–

Two solenoids for the shot and for the chip kick are meant to be installed;
but due to space shortage it cannot be installed.

To solve the above-mentioned problems, a new kick device is developed in

this research based on the following ideas.

–

The bobbin is changed from the column type to the ﬂat thin type by minia-
turization.

–

The core shape is made rectangular, the head and the core are the integral
parts.

2.2

Design of The Kick Device

This is a design to make the bobbin shape a ﬂat thin type from a past column
type. The adequate values of diameter and the length of the enameled wire
obtained for the last research are being used. Moreover when designing the device
we have to bear in mind that the stroke length of the bobbin will be same as
the column type which is 40mm. The material used for bobbin is polyacetal,
Aluminum is used for the head (non magnetic part) and SS400 is used for the
core part (magnetic substance). Figure 3 and Table 3 shows externals and the
detailed data of completed kick device A.

2.3

Performance evaluation experiment of kick device

In this study, the speed of the ball is measured with a high speed camera (Figure
4). And the performance of the kick device is evaluated. The measuring method
of the speed of the ball is outlined below:

1. The ball which was struck by the kick device at 100mm interval passing

between two lines was taken with a high speed camera

Fig. 3.

Kick devide A

Table 3.

The detailed data of kick device A

Stroke length[mm]

40.0

Diameter of enameled wire[mm] 0.6
Number of coil layers

Weight of solenoid[g]

185

Weight of head and core[g]

65.0

2. It is possible for the high speed camera to take a maximum of 1200frames/sec.

The number of frames is counted at 100mm intervals to estimate the ball
speed.

3. The speed of the ball can be calculated from the number of the frames. The

velocity is assumed to be v (m/s) and the number of frame is assumed to be
x; below is an expression used for the calculation.

120

[m/s]

(1)

Below is the speciﬁcation of the device (ﬁgure 4) which was used in the

experiment:

–

High speed camera: CASIO EX-F1

–

A charge circuit

（

Capacitor: 200V 3700uF, Switching use MOS-FET: 650V

47A, Power supply: Lithium ion battery, 11.1V, 1100mAh

）

–

Charge control board: H8 microcomputer

–

Ball: diameter:42.8 mm

weight:46 g

–

Using a wood of constant thickness or an iron plate for adjustment of the
height

Fig. 4.

A measuring equipment

Table 4 shows the result of the measurement of kick device A. The height of

the run(RBI) from the ﬂoor and the distance between the ball and the head tip
is evaluated beforehand and the best is used. For the kick device A the height
of the runs is 21mm, and the distance between the head tip and ball is 30mm.

Table 4.

Result of the measurement of kick device A

Iteration Ball speed [m/s]

8.76

8.7

9.16

8.82

8.96

8.82

9.09

9.16

8.82

Average

8.9

2.4

Improvement of kick device

Because the average ball speed of the kick device A falls below the average speed
of the column type; an improved kick device B was made. The modiﬁcation

from the kick device A, the stroke length is made to the size limit that can be
installed in the robot. It is expected that the best stroke length changes because
it is improved from the column type to a ﬂat thin type. From the last research
work it was observed that the speed of the ball changes with the stroke length.
Moreover , there is an advantage of reducing the number of coils by making the
bobbin thinner and increasing the space of the second solenoid. Figure 5 and
Table 5 shows externals and the detailed data of completed kick device B.

Fig. 5.

Kick device B

Table 5.

The detailed data of kick device B

Stroke length[mm]

52.0

Diameter of enameled wire[mm] 0.6
Number of coil layers

Weight of solenoid[g]

170

Weight of head and core[g]

74.8

Table 6 shows the result of the measurement of kick device B. The result of

the height of the run(RBI) from the ﬂoor and the distance between the ball and
the head tip is evaluated beforehand, and similar values of kick device A are
used about the height and the distance.

Table 6.

Result of the measurement of kick device B

Iteration Ball speed [m/s]

9.52

10.00

10.34

9.52

10.00

9.68

10.26

10.08

10.34

平均

9.98

2.5

Examination of the combination of bobbin and core

In an attempt of trying the check out the eﬀect of the core length on the ball
speed, the combination of bobbin and core that was worked on is changed and
an experiment is done.

Combination experiment 1

In the bobbin of kick device A, a long core of kick

device B is used. It is assumed that the distance between the head at its lowest
position and the ball is always 30mm, there is a ﬁxed height between the run and
the ﬂoor; the distance the aluminum core, joined metal part and the coil point is
assumed to be X. The fastest speed of the ball with respect to the distance X is
checked. Figure 6 shows the simpliﬁed schematic of the combination experiment.
The square dotted line shows the core when heads was at its lowest position.
Table 7 represents the relationship of the joined parts of the core and the coil
initial position with respect to the distance and speed. From the combination
experiment 1, the ball speed changes with respect to the distance X. The ball
speed is kept under the coil insertion ratio of 10%, if it is more than 10% it
will reduce the ball speed. Furthermore for the kick device A bobbin, if the core
length become longer, the ball speed can be more than 10m/s.

Table 7.

Result of combination experiment 1

X [mm] Ball speed[m/s]

10.34

9.52

8.45

Fig. 6.

Simpliﬁed schematic of the combination experiment

Combination experiment 2

In the bobbin of kick device B, a short core of kick

device A is used. The other procedure is same with combination experiment 1.
The relationship between the joined core and the coil initial position with respect
to the distance and the velocity(speed) is shown in table 8. The distinction
between the combination experiment 2 and 1 is; for the combination experiment
2 there is a gradual decrease of the ball speed with respect to the distance X.
Moreover, it is expected that kick device B can strike at a speed of 9.5m/s even
if aluminum that is the nonmagnetic material in the core is shortened by 15mm.
The kick device B is not only thin; but it is possible to make closer to the kick
device A in total length.

Table 8.

Result of combination experiment 2

X [mm] Ball speed[m/s]

8.28

8.11

7.69

7.5

6.86

2.6

Summary

From the experiment the combination of the bobbin of the kick device B and the
long core resulted to a ball speed of 10m/s; and it has the performance similar to
the kick device of the column type. Comparing from the miniaturization point of
view, the kick device A is short; while the kick device B is very thin. Kick device
B is suitable for stacking two solenoids. It can be said that miniaturizing was

achieved without a drop in performance of the kick device B. In this experiment,
only little experinment was done on the size of the SS400 core (magnetic), and
the relationship between the coil length with respect to the ball velocity (speed).
Our future task is for further optimization.

Improvement of the control circuit board

In this year, 3 points was examined regarding the circuit board improvement;
these are improvement of the eﬃciency of power supply circuit, sharing of robot
ID setting and DIP switch, and lastly the standardization of circuit pattern of
control circuit.

3.1

Improving the Eﬃciency of the Power Supply Circuit

The voltage supplied to the parts on the present board are 16[V], 9[V], 5[V] and
3.3[V]. So far the power supply voltage (step down voltage) has been done with
multiple use of three-terminal regulators. The respective voltage was supplied at
one power source.

Fig. 7.

Power supply circuit diagram

Fig. 8.

Eﬃciency of each stages of voltage conversion

However, because of the eﬃciency of these three-terminal regulators, the

conversion eﬃciency is very poor for the 3.3V terminal. The use of multiple
poor eﬃcient three-terminal regulators could have caused a gross ineﬃciency.
H8-3052F microcomputer only use the 9[V]. Since H8-3052F can work with the
range of voltage between 6.5[V] and 9[V], during the step down of voltage from
16[V] to 9[V], 7812 and 7809 of the three-terminal regulator are removed to
simplify and improve the eﬃciency; and two power source is integrated. The 16
[V] power source is for the motor drive, and the other power source for other
operations. 7.4V of two Li-Ion cells were used as the power source.

3.2

Sharing Robot ID Information with DIP Switchs

Our curent circuit board uses four dsPICs and one H8 microcomputer; the dsPIC
controls the rotation of each motor, while the peripherals such as the charging
circuits and the infrared ray sensors are controlled by the H8 microcomputer.
There is the problem of the peripherals being controlled by completely diﬀerent
circuit; because there is an interference between the power supply and the ra-
dio signal of the circuit. To improve this situation, the DIP switchs for setting
the Robot ID was shared between the circuits related to dsPIC and H8 micro-
computer. Robot ID is a number that can be used to recognize robot during a
competition when there are multiple robots. The numbers are usually up to 5.
For the input of this information, because there is usually a problem of convert-
ing from binary to denary, DIP switch was provided. However in order for there
to be same input ﬁgure without any kind of data miss reduced component count
and typographical error, the data needed to be shared.

Firstly, the method of input of dsPIC was considered. Three input terminals

were provided for the dsPIC, and the input was done in binary numbers. The
input values where entered as [1] for 0[V] and [0] for 5[V]. Also for the H8
microcomputer ﬁve input terminals are provided and it is entered in denary
number, the input values where entered as [1] for [opening] and [0] for [GND]
respectively. In order to unify these two input methods, ﬁrstly the three input
terminals are chosen and it was entered in binary. To keep compatibility for
current circuit, next parts were added to the interface for ID setting (Figure 9).

3.3

Standardization of the wiring pattern of control circuit

The DC motor is used to move the robot. The control unit of a motor consists
of the motor driver and the dsPIC which performs the control operations. In
order to distinguish between the controls of each motor, information with two
input terminals of dsPIC is used. Outside that the other peripheral circuits are
same. The function of the circuit is same, but the wiring pattern is diﬀerent
on the board, then it is very diﬃcult to check the wiring condition during the
inspection. For a uniﬁed and improved maintenance, the standardized wiring
pattern that can be used in any part was made.

Fig. 9.

Shared circuit for data compatibility

3.4

Summary

In this improvement, the board is more eﬃcient and easy to use compare to the
board used in the past. However in this case the size of board is slightly larger
than in the past. In the next project, we will check the current in each wire, and
replace the parts to proper parts and try to miniaturize the board.

Conclusion

We have described the speciﬁcations of our 2010 version robots. Furthermore,
we have described several topics from the developments of this year. The kick
device was examined, also the improvement of the control circuit, ID setting for
proper identiﬁcation and power supply board was demonstrated. The aim was
also to make a more durable circuit board.

References

1. http://www.robocup.org/
2. http://www.robocup.or.jp/
3. http://www.ode.org/