Paulina Vélez; Diego Andrade; Gustavo Guevara

Vélez, Andrade, Guevara

IMPLEMENTATION OF

TANGENTIAL

KICKING FOR

SOCCER

ROBOT

Paulina Vélez

1,2

, Diego Andrade

, Gustavo Guevara

Facultad de Ingeniería

, Universidad Nacional de Chimborazo - UNACH, Ecuador

Escuela Técnica Superior de Ingeniería

, Universidad de Sevilla, España

e-mail: paulinaandreavelez@gmail.com

esumen

bstract

which depends on the design of each user / developer.

It is managed at distance by different methods, such as

radio frequency control and its related technologies, e.g.

Bluetooth and WIFI (2).

The design can be limited to different rules that usually

have each contest. The propulsion system can be

elaborated with micro-motors or others types of engines,

such as servomotors and bushels. All of them are driven

by a Motor-Driver controller (3), commonly interpreted as H.

Bridge based on the geometric plane.

Introduction

A soccer robot

electronic device

a remotely-operated

designed to perform

movements in two dimensions. In

addition, the present approach has 4

Degrees Of Freedom (DOF) (1). It is

used in robot soccer competitions with

two teams of three members each one.

The robot can have two or more wheels,

This paper describes the development of a soccer robot, which integrates a prototype of shooting

based on the principle of the tangential curve, leading to perform such action into an arch. This effect

is caused by the tangential acceleration formed by the angle at the kick, and leads the object to move

over an area with different optimal positions for shooting. The kick is aimed at increasing the number

of the robot degrees of freedom while improving the efficiency of shooting, thus facilitating control

of the device for the tele-operator at crucial moments where the described mechanism is required.

Tele-operation control is achieved by Bluetooth technology and allows the device to make different

movements, e.g. go forward, turn to the left or right, go back and eventually kicking, all of them

referred to odometry principles that corroborate the theoretical performance of the design. To sum

up, this robot design provides the teleoperator with a more effective and simpler shooting, compared

to a conventional model.

keywords: soccer robot, tangential kick, tele-operated robot, odometry

Este artículo describe el desarrollo de un robot jugador de futbol, el cual integra un prototipo de

disparo o patada, basado en el principio de la curva tangencial, el cual genera un arco para realizar

el disparo. Este efecto se produce debido a la aceleración tangencial que se genera debido el ángulo

de la patada o disparo, y lleva el objeto a moverse a través de una zona con diferentes posiciones

óptimas para disparar. La patada alcanzada incrementa el grado de libertad del robot y a su vez

mejora la eficiencia de tiro, facilitando el control del robot por parte del teleoperador en momentos

críticos durante el juego. El control de teleoperación se consigue a través de un dispositivo móvil el

cual esta conectado al robot mediante bluetooth. El control que el operario realiza permite realizar

movimientos adelante-atrás, girar hacia izquierda y derecha, patear la bola. Estos movimientos se

rigen a los principios de odometría que corroboran el rendimiento teórico del diseño. Resumiendo,

este diseño proporciona al teleoperador aumentar su porcentaje de aciertos (goles) luego de ejecutar

un tiro, esto comprándolo con un modelo convencional.

palabras claves: robot jugador de fútbol, patada tangencial, robot teleoperado, odometría

A system of tangential kicking is a method to optimize

point shooting between a soccer robot and its rivals

(obstacles to beat), which has demonstrated effectiveness

when being implemented (4). By applying this concept,

the robot is able to solve a state of high speed by a route

planning and within a specific area of shot. The objective

is chosen according to the principle of least variation.

Step 1. The robot shooting points must

be calculated. In order to do so, the

following equations must be computed:

The trajectory takes place along a circular arc path, i.e. the

formation of the tangential shots is performed between

the original angle of the robot and the transition from the

straight line of curve, after the shot is made. It is worth

mentioning that the oscillation induced by the coup at

the robot is deleted with original angle adjustment. The

tangential cases are shown in Figure 1 (4).

Step 2. The robot R should move to

point of shooting A.

Step 3. The robot R adjust the angle of

shooting

Step 4. The robot R kicks the ball

Step 5. Return to step 1.

Tangential path shooting

This algorithm is useful in complex

game environments, which has several

obstacles, so both a path planning and

a strategy are required. Figure 3 shows

the path generation. The steps below

are required to apply the tangential path

shooting algorithm (4), as it is shown in

Figure 3.

Implementing this kicking system provides the tele-ope-

rator with a better control of the shot during a game ses-

sion, thus increasing the robot chances of scoring a “goal”

in the opposite arch. A greater number of trajectories at

different ways of shooting are generated, by means of

the tangential trajectory and the semi-effect of rotation,

affecting the impact and displacement.

Methodology

Simple path shooting

specific

contact kicking point of the ball is usually used

at the robot mechanism, which is strategically designed

so that, at the time of the contact, the ball would meet

the principle of the tangential trajectory. The following

5 steps are required to apply the simple path shooting

algorithm (4), as it is shown in Figure 2.

Step 1. Set the obstacle as the center of

the equation and the parameter W as it

radius. Calculate the shortest path and

intersect the circumference at the points

C1 and C3. Set the shortest vertical path

over the center of the obstacles and

Figure 3. Tangential Path shooting.

Figure 1. Cases of a tangential curve

Figure 2. Simple path shooting.

ISSN 1390-5740 Número 15 Vol. 1 (2016)

ISSN 2477-9105

Vélez, Andrade, Guevara

calculates the intersection of the points

C2 and C4 between the vertical path and

the circumference.

The user can send the followings commands from

the mobile application: ahead, go back, turn left, turn

right, right kick, left kick and dual kick. The mobile

device establishes the communication with the robot

by a bluetooth module. When the communications are

established, the robot starts to get commands from the

mobile application and the micro controller executes

them. This is shown in Figure 5.

Step 2. Check the distance between C2

and the boundary.

•

If it allows the robot to reach

its goal, the next step is to connect the

points C1, C2 and C3, generating the

path.

•

If it does not allow the robot to

reach the goal, then connect the point

C4, the robot and the target to generate

the path.

Soccer Robot design

The soccer robot has 4 actuators (DC

motors): 2 of them are intended to move

the robot by a mobile base, whereas the

other 2 actuators are aimed at setting the

kick. The actuators are commanded by

a driver that has been installed in the

main microcontroller. A Bluetooth mo-

dule has also been mounted on the main

board of the robot, enabling the commu-

nication with the mobile device. The ro-

bot design is composed of hardware and

software modules, which are described

in Figure 4.

Robot Movements

In order to generate the robot movements, a Tri-cycle

drive combining steering and driving has been used (5).

As the figure 6 shows (5), according to this design, each

speed motor defines the trajectory the robot will take.

Robot Operation

In order to allow the user to operate the

robot, a user application for a mobile

device has been elaborated. This appli-

cation establishes a Bluetooth connec-

tion with the mobile device. When the

connection between the robot and the

mobile is created, the robot can receive

data from the mobile application. The

data are interpreted by the microcontro-

ller, which also command the actuators

of the kicking and the mobile base.

Figure 6. Try-cycle drive.

Figure 4. Soccer Robot system

Figure 5: Functionality of the mobile application

The Odometry of the robot simplifies the problem in

determining the position (6) (7). In addition, the control

path is based on speed differences between the wheels.

The function of the system can be tested using numerical

values of the system. Following a differential drive, as

is shown in the figure 7, the robot is able to define it

trajectory.

Step 4. The robot kinematic

system is defined next:

Results and Discussion

Figure 8 shows the developed robot. This

prototype has been tested in various real

competitions. The mobile application

also has been tested in different mobile

devices, such as cellphones and tablets.

Tests on the robot were carried out by

It is required to comply with the 4 steps below (8) for the

differential drive (9) to be implemented:

Step 1. Based on the model of the robot, it is necessary to

set the relation between the inputs v_Land v_R and the

system X, Y and φ, where v_L stands for speed control of

the left wheel and v_R stands for speed control of right

wheel.

Step 2. Establish the robot movements, considering that

the robot can translate itself with linear speed v and rotate

with an angular speed w, which are defined by the equa-

tions below:t

means of both the conventional and

tangential models, whose aim was

to compare the hits between them.

According to the results, the latter

model makes the robot reach a higher

percentage in scored penalty kicks than

the former. In fact, Table 1 shows that the

tangential model achieves an increase of

30% in effectiveness with respect to the

conventional model.

v=R∙[(v_L+v_R )/2]

w=R∙[(v_L+v_R )/b]

where b is the separation between both

stands for the wheel radius.

wheels and R

Step 3. Compute the Integral of v and w, in order to define

the robot dynamics, according to the following equation:

x =v∙sinθ

y =v∙cosθ

φ =w

Figure 8. Soccer robot prototype.

Figure 7. Robot configuration for Mobile differential model

ISSN 1390-5740 Número 15 Vol. 1 (2016)

ISSN 2477-9105

Vélez, Andrade, Guevara

This increase at the shooting angle allows the robot to get

a greater number of

fine

shots (successes), for both penalty

kicks and shots performed in the middle of the game.

Therefore, its precision improves 2 points in comparison

with a shooting without applying the tangential kick.

Finally, as it can also be seen at Table 1, the tangential

model provides the tele-operator with a broader angle

shot, thus making the robot handling and operation much

easier.

Conclusions

The kicking speed increases 0.3m/s when

the tangential algorithm is applied, while

the reception angle keeps the same value.

Another advantage for the tangential

kick is the increase of the shooting angle,

i.e. without implementing the tangential

kick the angle saturates at 75º, whereas

Implementing the tangential kick algorithm on a Soccer

Robot leads to an increase of the number of scored

goals (fine shots) during the match, hence the success

percentage moves from 40% to 70% after implementing

the tangential algorithm.

it goes up to 110º when

path algorithm is applied.

the

tangential

eferencias

1. Vladan P.: Robot Soccer, RoboCup 2009 (WISA09), 2010.

2. Arvin F., Samsudin, K., Nasseri M.: Android Mobile Phone Controlled Bluetooth Robot Using

8051 Microcontroller, International Journal of Scientific Engineering and Research (IJSER),

2014. 2(7), pp. 14-17.

3. Pahuja R., Kumar N.: Design of a Differential-Drive Wheeled Robot Controller with Pulse-

Width Modulation, 2009 Conference on Innovative Technologies in Intelligent Systems and

Industrial Applications (CITISIA 2009), pp. 143-147.

4. Yang G.: Improved Shooting Algorithm Based on Zone and Tangential Arc in Robot Soccer,

Proceedings of the 2009 International Symposium on Web Information Systems and

Applications (WISA09), pp. 267-269.

5. Goris K.: Autonomous Mobile Robot Mechanical Design, Universiteit Brussel - Thesis. 2005.

pp. 9-27,

6. Borenstein J., Feng L.: Measurement and Correction of Systematic Odometry Errors in Mobile

Robots , Invited paper for the Journal of Robotic Systems, Special Issue on Mobile Robots,14(4),

pp.231-249

7. Borenstein J., Feng L.: Mobile Robot Positioning & Sensors and Techniques, IEEE Transactions

on Robotics and Automation. 1996 12(6), pp.869-880.

8. Solaque L., Molina M., Rodríguez E.: Seguimiento de trayectorias con robot móvil de

configuración diferencial, Ing.USBMed. 2014. 5(1), pp. 26-34.

9. Ollero A.: ROBOTICA, Manipuladores y robots móviles, Marcombo.

A sample of 10 shots

Tangential

kick

Normal

kick

Shot speed with motionless

ball

Reception angle

Angle shot

Scored penalty kicks

Percentage of score penalty

kicks

Scored penalty kicks in a

game

Hits percentage in a game

1.3 m/s

90°

110°

70°

70%

1 m/s

90°

75°

50°

40%

Table 1: Results of the subjective analysis