1

Festo Logistics Competition (FLC)

Rules and Regulations for RoboCup 2010

Version 1.5 (04-2010) Version History Date Changes 1.0 12-18-2009 1.1 01-30-2010 Notation of product components,

introduction of concept of empty pallet ( see 1.2), notation of “Market place” (see 1.1)

1.2 02-12-2010 Notation of safety zone and safety line, see 1.1 Restricted access to safety zones, see 2.3 and 2.6

1.3 02-23-2010 Correction of size of input store area and Outgoing Goods area (see 1.1)

Extension of the machine specification: Detection of wrong subassemblies and finishing of process steps. (see 1.3)

1.4 04-11-2010 RFID device with signal light ( see 1.1, section 3 with picture)

Specification of machine at test station and market place (1.3. sections 4 und 5)

Specification of operating modes of machines, see 1.3, sections 7,9 und 10.

Product delivery: 2.3, sections 3 and 6. Loading of machines: 2.4, section 4 More detailed description of complete work order in

terms of setup process and production process, see 2.4, sections 6,7 and 9

1.5 04-23-2010 Note: During the RoboCup GermanOpen this competition was tested the first time. Participants recognized numerous points which had to be simplified or specified in more detail. The following changes are the results. This will be the final version for Singapore 2010 Specification of the exact dimensions of the

competition field, see §1 Specification of the safety zone of the outgoing

goods area, see 1.1, section 3. Locations of the test stations and market places, see

1.1, sections 5 – 6. Dimensions of the machine spaces, see 1.1,

section 7 Locations of the production machines, see 1.1,

section 9 Dimensions of black lines were changed, see 1.1,

section 10. Data sheet of the mobile data carrier, see 1.2 The ID-code of the mobile data carrier at the test

stations will NOT communicated via OPC but will be visualized by the signal light at the test stations, see 1.3, section 5.

2

Specification of downtime of machines, see 1.3, section 9.

Specification of work order time of the machines at the test stations and market places, see 1.3, section 10.

Technical data of the machines, see 1.4 Specification of the machine processing, see 1.5 Specification of the rules about movement of the

robots of the non-logistic team, see 2.2, section 6-7. Specification of a valid position, see 2.2, section 8. Specification of rules concerning catching of pallets

and touching or attacking other robots, see 2.2, section 9-14.

During the game it is allowed to use any pallet on the field for production. There is no restriction of the position of the pallet, see 2.4, section 2.

All pallets used for a production process must be inside of the machine space during production, see 2.4, section 5.

Intermediate storage places for pallets, see 2.5, section 2.

Specification of time slots for the non-logistic team, see 2.6

Rules for W-LAN communication, see 2.9 Hints for image processing with web cameras using

jpeg compression, see 4.5

Preamble Concept of new competition: RoboCup and Festo are adopting an entirely new approach to mobile robotics competitions: The Festo Logistics League. The focus is no longer on sports in the form of soccer or ice hockey. Rather, the game environment takes its inspiration, actors and tasks from the world of industrial production:

Autonomous mobile robots as autonomous guided vehicles (AGV) ensure smooth logistic in a complex manufacturing process.

State-of-the-art technologies such as RFID and GPS navigation require competitors to use innovative ID and navigation methods.

The selection of suitable programming systems and methods before the start is perhaps the decisive challenge for the teams.

The other challenge is to develop and use the artificial intelligence of the autonomous mobile robot systems.

The mix of industrial relevance and sporting motivation means that every prospective logistic or production technology specialist who cannot participate misses out on a key experience.

3

Rules Philosophy: Following rules should not in any way describe the behavior of how the game is played.

Rules should only ensure that a fair competition takes place and encourage both technical and creative development.

Teams should avoid to search for gaps or inconsistencies in the rules to achieve advantages in specific game situations. If a team finds such gaps or inconsistencies, they are explicitly requested to report to the technical committee of this competition: dka@de.festo.com

Design Philosophy: All teams are working with the same equipment:

Fig.1: Robotino of Festo Didactic GmbH &Co.KG http://www.festo-didactic.com/de-de/lernsysteme/robotino-forschen-und-lernen-mit-robotern/

Any kind of sensors can be added or changed. It is NOT allowed to integrate a RFID device which is able to write data on a mobile data

carrier. Datasheet must be provided. No change of controller or mechanical system is allowed. The Competition Environment: A 5,6m x 5,6m arena represents the production hall in this practice-oriented manufacturing competition. The Unfinished Parts Store and Outgoing Goods are on opposite sides of the arena.

Fig.2: Competition arena The production hall contains 10 machines each with a specific function that is unknown to the teams at the start of the competition. The machines themselves are actually RFID read/write

4

devices which examine the subassemblies presented to them, establish their production status, and – depending on their function – write a new production status to the data carrier. The aim of the game: The autonomous guided vehicles must attempt to manufacture and deliver the maximum possible number of finished products. The challenges:

1. Teams first have to discover the unknown functions of the 10 machines as quickly as possible, store their locations in the production hall, and communicate this information to the other team players (that is, the other mobile robot systems).

2. The opposing saboteurs may block the paths between the Unfinished Parts store and Outgoing Goods area.

3. Last but not least: Right in front of Outgoing Goods is one more opponent who – like the goalkeeper in ice hockey – does everything possible to prevent the pallet from entering the goal, thus preventing delivery of the finished product.

Teams: Each team consists of three robots. Each robot has the same fixed device to push or hit a pallet.

Fig.3: This figure shows the device to push a pallet and to hit the pallet with the sides.

The dimensions of the robots are bounded by a cylinder with radius 0.4 m and maximum height of 0.7 m. One team – the logistic team - has the task to organize the logistic for producing and the delivery of the products, the opponent team has the task to disturb the production and delivery process.

5

Rules 1. Competition Field The competition arena consists of a field of 5.6 m x 5.6 m. The field is bounded by boards having a height of 0.5 m which makes sure that cameras of the robots are not interfered by objects outside of the arena.

Fig.4: Competition Field

1.1 Factory The factory consists of following components: Input store area which is marked by the “blue” area on the field. It is of size

0.4 m x 1.0 m.

Outgoing Goods area which is marked by the “green” area on the field. It is also of size 0.4 m x 1.0 m.

In front of the store areas there are rectangular safety zones of size 2m x 1m, see figure 4. The safety zones are bounded by black lines called safety lines. Additionally, in front of the Outgoing Goods area there is a rectangular zone of size 1 m x 0.50 m. This zone is bounded by a metallic stripe which can be detected by inductive sensors. It is called the front line of the store area.

At the opposite sides of the field there are black lines parallel to the bounded boards. These lines are called storage lines. The distance to the boards is in each case 0.4 m.

At two opposite edges there are test stations with a RFID reading device. They are bounded by black lines of length = 0.6 m. Taking the view in direction to “blue” area then one of the test stations is located at the edge on the left hand side of the “blue” area.

6

At the other two edges there are RFID writing devices bounded by black lines of length 0.6 m. These areas serve as a market place to receive raw material – un-machined subassembly S0 - for the production process.

There are 10 production machines distributed on the interior of the competition field. The spaces of the machines are bounded by squares of black lines of length = 0.60 m. These spaces are called the machine spaces of the factory. These machines consist of read-write RFID devices equipped with an integrated 3-coloured (red, green, yellow) LED signal light.

The locations of the production machines are distributed as follows: Suppose the origin of the x,y coordinate system is located in the edge of the market place on the right hand sided of the “blue” area. The positive y-axis shows in direction to the “green” area and the positive x-axis shows in direction to the test station at the left hand side of the “blue” area, see following picture:

Coordinates of the centre points of the production machines:

x y 0,56 m 2,80 m 1,68 m 1,68 m 1,68 m 2,80 m 1,68 m 3,92 m 2,80 m 2,80 m 3,92 m 1,68 m 3,92 m 2,80 m 3,92 m 3,92 m 5,04 m 2,80 m 5,04 m 3,92 m

All black lines have a width of 19 mm.

The metallic lines have a width of 50 mm.

7

Fig.: Competition field with marked areas 1.2 Product Definition A pallet will be represented by a puck, see fig.5. Each pallet carries one component. Each component is represented by a RFID mobile data carrier with a well defined part number. The pallet is empty if the part number equals 0.

Fig.5: Pallet with data carrier A component is an un-machined subassembly S0 if the part number of the data carrier = 10000. A component is a subassembly S1 if the part number of the data carrier = 20000. A component is a subassembly S2 if the part number of the data carrier = 30000. A component is the finished product P = ROBI if the part number of the data carrier = 40000.

8

The un-machined subassemblies S0 will be provided in the Input Store area. The product and the other subassemblies must be produced in the factory. The production processes require following components: Production of S1 requires 1 un-machined subassembly S0 Production of S2 requires 1 subassembly S1 and 1 un-machined subassembly S0 Production of the finished product P requires 1 subassembly S2, 1 subassembly S1 and

1 un-machined subassembly S0.

Empty pallet: In case of an empty pallet the data carrier can be changed into an un-machined subassembly S0 by use of one of the writing RFID devices in one of the “market places” of the factory. Technical data of the data carrier:

Dimension: Ø 20 mm, height: 2.5 mm Data transfer: inductance coupling Working frequency; 13.56 MHz Memory read/write Memory type: EEPROM Memory size: 128 Byte Freely usable memory: 112 Byte Number of read operations unlimited Number of write operations: 105 Typical read time: 2 ms/byte Typical write time: 3 ms/byte Radio communication and protocol standards ISO 15693

1.3 Machine Definition There are five machines producing the subassemblies S1. The processing time takes

WT1 seconds ( WT = writing time) of playing time, i.e. after WT1 seconds the code of the RFID data carrier will be changed to 20.000.

There are three machines producing subassemblies S2. The processing time takes WT2 seconds of playing time, i.e. after WT2 seconds the part number of one of the RFID data carriers is changed to 30.000 and the other one is changed to 0, i.e. the corresponding pallet is empty.

There are two machines producing finished products P. The processing time takes WT3 seconds of playing time, i.e. after WT3 seconds the part number of one of the RFID data carriers is changed to 40.000 and the other ones to 0, i.e. empty pallets.

There is one machine at each market place. This machine replaces an empty pallet or any other subassembly by the raw material S0.

There is one machine at each test station. This machine checks the product type on the pallet and communicates the product ID-code to the robot system. The communication will be done as follows:

o Empty pallet := no light of the signal lamp is on. o Raw material S0 := only the yellow light is on o Subassembly S1 := only the yellow and red lights are on o Subassembly S2 := only the red light is on o Finished product P:= all lights are on.

9

Important: The type of a production machine is not fixed and will be changed before start of a game.

The production machines might be in different operating modes: o Operating mode ready: green LED light is on o Operating mode processing: green and yellow LED light is on. o Operating mode setup finished: only the yellow LED light is on o Operating mode work order finished: green LED light is on o Operating mode wrong material: yellow light is flashing (2 Hz). o Operating mode out of order: red LED light is on

Time for finishing setup process = 2 seconds

There is a random generator to cause a downtime of machines. Downtime will be at least

30 seconds but no longer than 90 seconds.

Downtime of machines: maximum of 3 machines of different type at the same time

During a game period a machine will have at most two downtimes. After a downtime the machine will be at least 5 minutes in running mode.

The machines at the market places have following operating modes: o Operating mode ready: green LED light is on o Operating mode processing: green and yellow LED light is on. o Operating mode work order finished: green LED light is on o Operating mode out of order: red LED light is on.

The operating mode out of order will only appear if there is “real” error in the system.

The machines at the test stations have following operating modes: o Operating mode ready: green LED light is on o Operating mode processing: green and yellow LED light is on. o Operating mode work order finished: display of the test result following above

specification o If the pallet will be removed then the station changes in the ready mode.

Time for finishing work order of the machines at the market places and the test stations

is equal to 2 seconds.

1.4 Technical Data of the Machines

Fig. RFID device with signal light

10

Height of machines: 280 mm Width of machines: 160 mm Depth of machines: 100 mm

Technical data of the read/write head: o Housing rectangular:

Housing diameter: 40 mm Housing height: 65 mm Housing material Plastic: PBT-GF30-V0, black Material active face Plastic: PA6-GF30, yellow

o Operating voltage 10…30 VDC DC rated operational current: ≤ 80 mA Operating voltage DC Data transfer inductance coupling Working frequency: 13.56 MHz Radio communication and protocol standards ISO 15693 Read/write distance: max. 115 mm Output function 4-wire, read/write

o Electrical connection Connectors, M12 x 1 Vibration resistance 55 Hz (1 mm) Shock resistance 30 g (11 ms) Protection class IP67 Operating voltage display LED green

1.5 Machine Processing If the robot moves a pallet to one the machines such that the data carrier on the pallet is

in the reading area of corresponding RFID head then reading of the data carrier will be immediately started.

After reading, the machine displays immediately its operating mode.

Writing process starts after 2 seconds in order to make sure that the robot has finished moving.

Afterwards the robot has to wait until the machine displays: Processing step is finished. If the robot is moving away the pallet before showing this change of operating mode then the new status might be not written to the data carrier on the pallet.

2 Rules for the Production Process 2.1 General Strategy Main goal of the game: Deliver finished products P as much as possible in Outgoing Goods area. Winner of a match is the team with most delivered finished products. At the beginning of a game the locations of the machines are known but not the type of the machine, see chap. 1.3. Therefore the first challenge of the logistic team is to identify the locations of the different machine types of the factory. A strategy could be to deliver un-machined subassemblies S0 to all machines as fast as possible and then to find out which machines do not finish the production. So the other 5 machines must be the machines

11

producing the subassemblies S2 or the finished product P. Here the challenge is to develop a strategy how to spread out the information to all team members. The next step must be to identify the three machines producing subassemblies S2 and the two machines producing the finished product P. After identification of the machines types the main challenging task is to create a scheduling of the logistic to increase the output of finished products P. To finish a production process the logistic team must take care that at least one of pallets is at the right position of the RFID read-write device and the other ones in the machine space. After the production process is finished (machine is in the operating mode ready) all pallets in the machine space must be delivered to the next places. Additionally, your scheduling may be disturbed by two events:

Team members of the opponent team may block the direct way to the machines. You have to find a new way without touching this obstacle.

There is random generator to cause a downtime of machines.

The final challenge is to carry the pallet with the finished product P into the Outgoing Goods area. Here the robot has to hit the pallet into this goal area because he is not allowed to cross the front line (metallic tape) of this area. Also, it might be possible that one of the opponent team may prevent like a goal keeper that the pallet slips into the Outgoing Goods area. 2.2 Start of the Game The regular playing time of a competition match is divided into two halves à 15 minutes.

After the first half there is a break of 5 minutes. The playing time will be stopped at the end of a half or because of an irregularity pointed out by the referee. The playing time will be continued if the referee restarts the game. Thus the actual time of a match may last for more than 35 minutes.

After the first half of a match the roles of the teams will be changed.

At the start of a game all members of the logistic team must be on the storage line of the input store area and all members of the opponent team must be on the storage line of the Outgoing Goods area.

The input store area is filled up with 25 (or 30) pallets with un-machines subassemblies S0. All pallets are behind the storage line.

The game will be started only if no robot is moving. If the referee blows the whistle playing time will be started and all robots of the logistic team may immediately move. For the start it is allowed that teams may press one button for each robot.

The robots of the opponent team - the non-logistic team - may start moving at any time to an arbitrary valid position and have to stop after reaching the position. They are not allowed to stop in between. If a robot stops then he has to stay at this position. All robots of the opponent team must start moving at the same time.

Moving time should not increase 10 seconds. Otherwise the referee will interrupt the game and the robot must move to a position shown by the referee which is a maximum of

12

0.5 m away from the original position.

A robot is at a valid position if following conditions are satisfied: o No part of the robot touches the machines space or the boundary line of the

machine space of any station. o No part of the robot touches the safety zone of the input area or the safety line. o Only one robot of the non-logistics team may be inside of the safety zone of the

Outgoing Goods area or touches the safety line.

During movement a robot of the non-logistic team may catch a pallet which is outside of a machine space or the safety zone of the input area.

Robots may touch each other but it is not allowed to attack or push each other.

If the referee interrupts the game the robots have to stop their movement. For this interruption it is also allowed to stop the robot movement by pressing one button.

If a robot of the non-logistic team is at a non-valid position the referee will interrupt the game and the robot must move to a position shown by the referee which is a maximum of 0.5 m away from the original position.

If a robot attacks or pushes a robot of the opponent team then the referee interrupts the game and the robot must move to a position shown by the referee which is a maximum of 0.5 m away from the original position. Further, the faulty robot may only start moving 10 seconds after restart.

If the referee cannot decide which robot is responsible for attacking or pushing the other one then both robots must move away and have to wait 10 seconds after restart.

2.3 Product Delivery A pallet will be counted as a delivered product if and only if following conditions are satisfied: The pallet has completely crossed the storage line and is inside the “green” Outgoing

Goods area.

The pallet was not touched by one player of the logistic team being behind or touching the front line of the Outgoing Goods area.

The referee will take out the pallet and will check if the product ID corresponds to the ID of a finished product P.

The game will be not interrupted after delivery of a pallet.

During playing time only one of the non-logistic team can be behind the safety line of the Outgoing Goods area.

This robot may move and behave like a goalkeeper if he is behind the front line (metallic tape). He is not allowed to touch the front line except he is on the way to move in. Otherwise the referee will interrupt the game.

o If the robot has touched the front line the robot must move back at least 0.3 m and is not allowed to move 10 seconds after restart.

13

o If another team member of the non-logistic team was inside of the safety zone or has touched the safety line, this robot must move away such that there is a distance of at least half meter between robot and the safety line. Further, the faulty robot may only start moving 10 seconds after restart.

If a pallet could not be delivered in the Outgoing Goods area then members of the logistics and non-logistics team can try to catch the pallet without attacking or pushing each other. Otherwise the referee interrupts the game and the faulty robot must move to a position shown by the referee which is a maximum of 0.5 m away from the original position. Further, the faulty robot may only start moving 10 seconds after restart.

If the referee cannot decide which robot is responsible for attacking or pushing the other one then both robots must move away and have to wait 10 seconds after restart.

2.4 Loading of Machines The main task of the logistic team is to load the machines on time with the right material. The loading of a machine has to be done in the machine space.

Any pallet on the competition field might be used for loading a production machine.

Not correct material type will be indicated by flashing yellow light.

Loading can be only started if o the machine is ready to receive new material (machine must be in the operating

mode ready) or o it has finished a setup process and is waiting on a next subassembly.

Processing of subassembly S2 or final product P can only be started if all required

components are detected by the machine and corresponding pallets are inside of the machine space, i.e. no one of them is completely outside.

If a pallet belonging to a production process of S2 or P is outside of the machine space, then the referee will stop the game and will take out both the pallet being outside of the machine space and the pallet which is under processing.

Processing of S2 and P requires the supply of additional material. This process will be called the setup process. In general, a work order consists of following steps:

o Work order = setup process + production process

Start of the work order: Green LED light and yellow LED light are switched on. Work order is finished: Yellow light will be switched off and only the green light is on. Compare section 1.3 for the specification of the different operating modes of a production machine.

Important Hint: In case processing requires more than one component then only the part number of the component of the last pallet will be changed to the new product type. All the other ones were immediately changed to empty pallets during the setup process!

The setup process may consist of one step (in case of S2) or two steps (in case of P). The finishing of a setup step will be indicated that the green light will be switched off. The start of the next setup step or the production process will be indicated that the green LED light will again be switched on, see the specification of the different operating modes of a

14

production machine in 1.3.

2.5 Unloading of Machines Unloading of a machine can be immediately started if the machine indicates “ready for

next processing cycle”, see above specifications (2.4).

Pallets with subassemblies S1 or S2 can be moved to the machine spaces of next free machines which can process these products or must be stored in the safety zone of the input area. Empty pallets have at first to be removed to the “Market Place” and can be then used for further processing.

2.6 Obstacles The main task of the opponent of the logistic team is to avoid the delivery of products. This team plays the role of dynamical obstacles. Some rules are already specified in 2.1 – 24. There are a few further restrictions: Robots of the non-logistic team are not allowed to catch pallets being inside of a machine

space.

Robots of the non-logistic team are only allowed to move at a maximum of 10 time-slots. These time-slots will be internally managed by the non-logistic team.

Between the time-slots no robot of the non-logistic team being outside of the front line of the Outgoing Goods area is allowed to move. Otherwise the referee will interrupt the game and all robots of the non-logistic team must stay at their positions for 1 minute after restart.

2.7 Teams and Players

A match is played by two teams, each consisting of not more than 3 players. A match may not be started if a team has no players. Robots of the same team will be marked by a colored shirt above the controller housing.

The shirts have three equal stripes of color either green – white – green or blue – white – blue depending on the color of their goal.

Fig.6 Shirts can be easily put on

15

Each player is a mobile robot system of type Robotino®, see figure 1, with the same device to hold and to hit the pallet.

The robots are working autonomously or remote controlled via WLAN by programs running on a PC. Each PC can only control one robot. Communication between the PC’s is allowed. If the game is running no participant is allowed to do any changes of the PC program. The referee is the only authority deciding to start, to stop or to interrupt the game. Then the participants have to stop their mobile robot systems by remote interaction.

If the game will be started or restarted, then the participants have the possibility to start their program(s) by one (!!) click on a PC key button.

2.8 Programming Programming can be done in C, C++, C#, Java, Labview, Matlab or Robotino® View, see http://www.festo-didactic.com/robotinoview  Each team is responsible for the compiler of corresponding programming language. 2.9 W-LAN Communication In order to minimize the difficulties with interferences of W-LAN communication all participants have to accept following communication concept: There will be one external access point Allnet265a

Fig. Allnet access point

Technical description:

o Transfer rate: 54 Mbps o Data link protocol: 802.11.g o Frequency: 2.4 Ghz o DHCP is supported o Encryption: WEP/WPA1/WPA2 o Power supply: 12 VDC, 1A ( min. 5 V, 2.4 A) o SSID: RobotinoAPX.1 o AP-IP address: 172.26.101.2 o Netmask: 255.255.0.0

All PC’s or Laptops have to switch off their local W-LAN interface and will be connected

to the access point by LAN cable via a switch.

16

All robots will get a fixed IP address 172.26.1.x where x runs between 1 and 50

3 Competition

3.1 Competition Schedule

First Round: All teams play against each other. Evaluation:

The winner of each match obtains 3 points, the loser team obtains 0 points, Both teams obtain 1 point if the score of the match is even. The ranking is given by the number of points. In case of two or more teams have equal number of points the number of delivered

products will determine the ranking. If still there is no clear ranking then there will be a “penalty shootout” between the teams.

What is a Penalty Shootout? A penalty shooting will be done as follows:

First, it will be decided which team will do the penalty shooting. This team is called the attacking team. The other team is called the defensive team.

One player of the attacking team will be selected to perform the penalty shot. One player of the defensive team will be selected as goalkeeper. The goal is the

Outgoing Goods area. The player of the attacking team starts moving with the pallet at the centre point of the

competition field if the referee releases the penalty shot. There is only one chance to hit the pallet into the goal.

The goalkeeper can try to stop the attacking player but no wheel of the robot is allowed to cross the front line of the goal.

A Penalty Shootout will be done as follows: Each team must select one player to be the goalkeeper.

17

Each team gets the right for three penalty shootings. After each penalty shooting the role of the attacking team will be changed.

By lottery it will be decided which team will first start with the penalty shooting. If the number of scored goals is still equal then this penalty shooting will be continued

until one team scores and the other not. Semi Finals:

The first four teams attain the Semi Finals. The first team plays against the fourth team and the second one plays against the third one. The winner teams will be determined by the rule “Best of Three”, i.e. the team which wins at first two games between the opponent teams is the winner and will reach the Final. Each match must have a winning team. Otherwise there will be a penalty shootout. Finals:

The Final will be played by the winner of the Semi Finals. The match for the third place will be done between the loser teams of the Semi Finals.

4 The Mobile Robot System

The mobile robot system Robotino® is a platform with an open mechanical interface for the integration of additional mechanical devices and an open electrical interface to integrate easily additional sensors or motors of devices. Power is supplied via two 12 [V] lead gel batteries which permit a running time of up to two hours. The scope of delivery likewise includes a charging device. Robotino® is driven by 3 independent, omnidirectional drive units. They are mounted at an angle of 120° to each other. The three omnidirectional drive units of Robotino® , defines the robot as being holonomic, meaning that the controllable degrees of freedom equals the total degrees of freedom of the robot. The drive units are integrated in a sturdy, laser welded steel chassis. The chassis is protected by a rubber bumper with integrated switching sensor. Robot dimensions: Diameter: 370 mm Height including housing: 210 mm Overall weight: approx. 11 kg Maximal payload of about 6 kg

4.1 Drive Unit

Each of the 3 drive units consists of the following components: DC Dunker motor with nominal speed of 3600 rpm and nominal torque

of 3.8 Ncm. Integrated planetary gear unit with a gear ratio of 4:1. Omnidirectional wheels of diameter of 80 mm. Toothed belt with gear wheels providing a transmission ratio of 4:1.

Altogether this provides a gear transmission ratio of 16:1.

18

Incremental encoder with a resolution of 2048 increments per motor rotation.

Fig. 7. Drive unit with motor (1), encoder (2), omnidirectional wheel (3), planetary gear (4), toothed belt (5)

The motor speed will be controlled via a PID controller implemented on a Atmel microprocessor of the controller board of Robotino®.

4.2 Sensors

Robotino® is equipped with 9 infrared distance measuring sensors which are mounted in the chassis at an angle of 40° to one another. Robotino® can scrutinise all surrounding areas for objects with these sensors. Each of the sensors can be queried individually via the controller board. Obstacles can thus be avoided, clearances can be maintained and bearings can be taken on a selected target. The sensors are capable of accurate or relative distance measurements to objects at distances of 4 to 30 cm. Sensor connection is especially simple including just one analogue output signal and supply power. The sensors’ evaluation electronics determines distance and read it out as an analogue signal. The anti-collision sensor is comprised of a switching strip which is secured around the entire circumference of the chassis. A reliably recognisable signal is thus transmitted to the controller unit. Collisions with objects at any point on the housing are detected and, for example, Robotino® is brought to a standstill. The inductive proximity sensor is supplied as an additional component. It serves to detect metallic objects on the floor and is used for continuous-path control, e.g. it might be used to detect the blue lines (metallic stripes) on hockey field. It reads out signals of varying strength depending upon whether it is located in the middle or at the edge of the metal strip. Path tracking can thus be controlled in a differentiated fashion. The inductive proximity sensor must be attached to the mounting furnished for this purpose, and must be connected to the I/O interface. The output voltage is 0 to 10 [V]. The sensing range is 0 to 6 mm. Path tracking can also be implemented with the two included diffuse sensors. Flexible fibre-optic cables are connected to a fibre-optics unit which works with visible red light. Reflected light is detected. Different surfaces and colours produce different degrees of reflection. However, gradual differences in reflected light cannot be detected. The sensors must be attached to the mountings furnished for this purpose, and must be connected to the I/O interface.

19

Robotino® is equipped with a color webcam. The webcam is equipped with a USB interface and provides an integrated jpeg compression. It supports a colour depth of 24 bit true colour and a VGA resolution with 15fps. The reason for jpeg compression is that image processing can be done on an external PC via WLAN connection. Also, there will be integrated a digital Gyroscope providing a high accuracy of the odometry in the virtual factory.

4.3 Controller Board

The controller housing is connected to the wiring in the chassis via one plug-in. Thus you can easily take off the controller housing and you have direct access to the mechanical system. The controller system of Robotino® is divided into two parts – an embedded PC and a microcontroller interface card:

Fig. 8. Controller of Robotino® consists of an embedded PC and a microcontroller interface board.

The main controller is the embedded PC 104 plus controller with the 800 MHz processor AMD LX800. The PC has a SDRAM of 128 MB and is provided with a 1 GB flash card. There are numerous communication interfaces on board: 2 x Ethernet 2 x USB 2 x RS232 Parallel port and VGA port Wireless LAN Access Point following the standards 802.11.g and 802.11.b. The access

point can be switched into a client mode. As an option you may use WPA2- coding.

4.4 Software

There is a Ubuntu Linux operating system with real time kernel running on the embedded PC 104. The main part of the controller is the Robotino® server, a real time Linux application. It controls the drive units and provides interfaces to communicate with external PC applications via W-LAN. There is an API with libraries which allow you to create applications for Robotino® in numerous programming languages: C++ und C C# .net and JAVA MatLab and Simulink Labview You may find a lot of examples concerning using the different API’s in the public forum “openrobotino”, http://www.openrobotino.org

20

.

4.4.1 Robotino® View Robotino® View is a graphical programming language with numerous prepared function blocks you can easily connect via input and output parameters to establish more complicated function diagrams. You can use these function diagrams as subprograms for more complex programming sequences. To build up general programming sequences Robotino® View follows the international standard IEC 61131-3. You may run Robotino® View on an external PC and Robotino® View communicates directly with the Robotino® Server on the PC 104 via W-LAN in order to control the robot system. The function blocks receive a direct feedback of the hardware components such that you can live interact with the robot system. On the other hand you can download Robotino® View programs into the PC 104 in order to run the applications completely autonomously. There is a well defined interface to develop own function blocks in C++. 4.5 Image Processing Depending on the Robotino version it might happen that the standard web camera only provides image data by jpeg compression. This is very useful if you run your image processing on the PC and exchange the data via W-LAN. However, if you would like to run your image processing algorithms on the Robotino controller then the processor is not powerful enough in order to pack and to unpack the image data in a reasonable time. Thus we recommend for running image processing algorithms on the Robotino controller to use a camera without jpeg compression, e.g. use the low cost Logitech web camera C250:

Fig. Logitech C250