Gotting HG G-73650ZD Manual

Documentation HG G-73650ZD
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Navigation Controller
Basics, Setup and Software
HG G-73650ZD
English, Revision 04 Dev. by: ML / LM
Date: 28.10.2016 Author(s): RAD / AF / Ext.
Götting KG, Celler Str. 5, D-31275 Lehrte - Röddensen (Germany), Tel.: [phone] / 80 96 -0,
Fax: [phone] / 80 96 -80, eMail: [email protected], Internet: www.goetting.de

Contents HG G-73650ZD
English, Revision 04, Date: 28.10.2016 1
Contents
1 Introduction.......................................................................7
1.1 Tasks of the Navigation Controller........................................... 7
1.2 Intended Use .......................................................................... 7
1.3 Requirements / Options .......................................................... 8
2 Basic Principles of Track Guidance....................................9
2.1 Suitable and Unsuitable Vehicle Types.................................... 9
2.2 System Composition ............................................................. 10
2.3 Position Determination with Sensor Fusion............................ 10
2.3.1 The Odometry ............................................................................. 11
2.3.2 Sensors for Navigation ................................................................ 11
2.3.2.1 Transponder Antenna ............................................................. 11
2.3.2.1.1 Single Antenna Evaluation — Calculation of the Position
with one Antenna ......................................................13
2.3.2.1.2 Double Antenna Evaluation ...................................... 15
2.3.2.1.3 The Triple Antenna Evaluation.................................. 16
2.3.2.1.4 Initialising the Transponder Sensor Fusion (Placing the
Vehicle on the Track) ................................................16
2.3.2.1.5 The Transponder List ............................................... 17
2.3.2.2 GPS ....................................................................................... 17
2.4 Coordinate Systems.............................................................. 18
2.4.1 The Vehicle Coordinate System ................................................... 18
2.4.2 The Local Coordinate System ...................................................... 18
2.4.3 Characteristics of the Coordinate Systems ................................... 19
2.5 Reconstruction of the Route (Segments) ............................... 20
2.5.1 Virtual Tracks .............................................................................. 20
2.5.2 The Segment File ........................................................................ 21
2.5.2.1 Structure of the Segment File.................................................. 21
2.5.2.2 The Segment Search .............................................................. 23
2.5.2.3 Selection of Segments ............................................................ 23
2.5.2.4 Transmission of Segmente ...................................................... 25
2.5.3 Attributes..................................................................................... 26
2.5.3.1 Offset Driving.......................................................................... 26
2.5.3.2 Inverted Steering .................................................................... 27
2.5.3.3 Stop Distance ......................................................................... 28
2.5.3.4 Spot Turn ............................................................................... 29
2.5.4 Creating / Editing of a Segment File ............................................. 29
2.6 Track Guidance .................................................................... 30
2.6.1 Speed Calculation ....................................................................... 32
2.6.2 Steering Angle Calculation........................................................... 32
2.6.3 Guidance of an omnidirectional Vehicle........................................ 32

Contents HG G-73650ZD
English, Revision 04, Date: 28.10.2016 2
2.6.4 Guidance of a non-omnidirectional Vehicle................................... 34
2.6.5 Driving Modes ............................................................................. 35
2.6.5.1 Idle Mode ............................................................................... 35
2.6.5.2 Parameter Test Mode ............................................................. 35
2.6.5.3 Automatic Mode...................................................................... 35
2.6.5.4 Remote Control Mode ............................................................. 36
2.6.5.5 Vector Steering Mode ............................................................. 36
2.7 Communication with the Vehicle Control (e.g. PLC) ............... 37
3 Hardware ........................................................................38
3.1 Mounting .............................................................................. 39
3.2 Front Panel........................................................................... 40
3.3 Control Elements on Front Panel........................................... 40
3.4 Display Elements on Front Panel .......................................... 40
3.5 Connectors ........................................................................... 41
3.5.1 ETH ............................................................................................ 41
3.5.2 USB ............................................................................................ 41
3.5.3 SIO 1 (GPS Receiver).................................................................. 42
3.5.4 SIO 2 .......................................................................................... 42
3.5.5 CAN 1 ......................................................................................... 43
3.5.6 CAN 2 ......................................................................................... 43
3.5.7 SIO 3 .......................................................................................... 43
3.5.8 POWER....................................................................................... 44
3.5.9 IO ............................................................................................... 44
3.5.10 ENCODER 1 / ENCODER 2 ......................................................... 44
3.5.11 PROG ......................................................................................... 45
3.5.12 ANT1 / ANT2 ............................................................................... 45
3.6 Extension module Feldbus .................................................... 45
4 Software .........................................................................46
4.1 Main menu ........................................................................... 47
4.2 Status menu ......................................................................... 48
4.2.1 Navigation menu.......................................................................... 48
4.2.1.1 Status..................................................................................... 48
4.2.1.2 Deviation ................................................................................ 49
4.2.1.3 Seg. Table .............................................................................. 49
4.2.1.4 Segment ................................................................................. 50
4.2.1.5 PLC ........................................................................................ 51
4.2.2 Transponder menu ...................................................................... 51
4.2.2.1 Antenna.................................................................................. 52
4.2.2.2 Result..................................................................................... 52
4.2.2.3 Odometry................................................................................ 53
4.2.3 GPS ............................................................................................ 53

Contents HG G-73650ZD
English, Revision 04, Date: 28.10.2016 3
4.2.3.1 GPS ....................................................................................... 54
4.2.3.2 ONS ....................................................................................... 54
4.2.3.3 Controller Deviation ................................................................ 55
4.2.3.4 Controller Correction............................................................... 55
4.2.3.5 Status..................................................................................... 55
4.2.4 GPS Receiver.............................................................................. 56
4.2.4.1 UTC........................................................................................ 56
4.2.4.2 Status..................................................................................... 56
4.2.4.3 Position .................................................................................. 56
4.2.4.4 Diff. Data Age ......................................................................... 57
4.2.4.5 Satellites ................................................................................ 57
4.2.4.6 Accuracy ................................................................................ 57
4.2.4.7 Base Vector ............................................................................ 57
4.2.4.8 Heading.................................................................................. 57
4.2.5 Error ........................................................................................... 58
4.2.6 TCP ............................................................................................ 59
4.3 Configuration menu .............................................................. 59
4.3.1 Configuration —> Main ................................................................. 60
4.3.2 Configuration —> Guidance .......................................................... 62
4.3.3 Wheels........................................................................................ 63
4.3.3.1 What type of vehicle is involved?............................................. 63
4.3.3.2 The non-omnidirectional vehicle .............................................. 63
4.3.3.3 The omnidirectional vehicle..................................................... 64
4.3.3.4 Which wheels should be used for the odometry? ..................... 64
4.3.3.5 How are the positions specified on the vehicle?....................... 64
4.3.3.6 Configuration —> Wheels ......................................................... 65
4.3.4 Configuration —> Antennas........................................................... 67
4.3.5 Configuration —> Accuracy ........................................................... 68
4.3.6 Configuration —> Steer Controller................................................. 69
4.3.7 Configuration —> Speed Controller ............................................... 72
4.3.8 Configuration —> Sensor Fusion Transponder............................... 73
4.3.9 Configuration —> Sensor Fusion GPS ........................................... 74
4.3.10 Configuration —> Gyro.................................................................. 77
4.3.11 Configuration —> Servo ................................................................ 78
4.4 Network menu ...................................................................... 80
4.5 Config File menu .................................................................. 81
4.5.1 Upload Configuration —> Load parameters from a file on the PC into
the navigation controller .............................................................. 81
4.5.2 Download —> Transfer parameters from the navigation controller into
a file on the PC ........................................................................... 82
4.6 Segment File menu............................................................... 82
4.6.1 Upload Segment File —> Transfer a segment file from the PC into the
navigation controller .................................................................... 83
4.6.2 Download Segment File —> Transfer segment file from the navigation
controller into a file on the PC...................................................... 83

Contents HG G-73650ZD
English, Revision 04, Date: 28.10.2016 4
4.7 Segment Table menu............................................................ 84
4.8 Transponder File menu ......................................................... 85
4.8.1 Upload Transponder File —> Transfer a transponder file from the PC
into the navigation controller ........................................................ 85
4.8.2 Download Segment File —> Transfer transponder file from the naviga-
tion controller into a file on the PC ............................................... 86
4.9 Transponder Table menu ...................................................... 86
4.10 'Parameter Test' menu.......................................................... 87
4.10.1 Requirements for switching into the different modes..................... 88
4.10.2 Possibilities in the 'Idle' mode ...................................................... 88
4.10.3 Possibilities in the 'Test' mode ..................................................... 88
4.10.4 Possibilities in the 'Auto' mode..................................................... 89
4.10.5 Specification of segments ............................................................ 89
4.10.6 Setting a starting position ............................................................ 89
5 Commissioning................................................................90
5.1 Interfaces usually connected................................................. 90
5.2 Test / real operation.............................................................. 90
5.3 Commissioning the communication ....................................... 91
5.4 Setting the parameters.......................................................... 91
5.4.1 Configuration -> Main .................................................................. 92
5.4.2 Configuration —> Guidance .......................................................... 93
5.4.3 Configuration —> Wheels.............................................................. 93
5.4.4 Configuration —> Antenna ............................................................ 95
5.4.5 Configuration —> Accuracy ........................................................... 96
5.4.6 Configuration —> Steer Controller................................................. 96
5.4.7 Configuration —> Speed Controller ............................................... 97
5.4.8 Configuration —> Sensor Fusion ................................................... 97
5.4.9 Configuration —> Gyro.................................................................. 98
5.4.10 Configuration —> GPS .................................................................. 99
5.5 Creating the segments .......................................................... 99
5.6 Simulation without vehicle and vehicle controller ..................100
5.7 Simulation without vehicle and with vehicle controller ...........101
5.8 Commissioning a vehicle......................................................101
5.8.1 Testing and optimizing the parameters ....................................... 101
5.8.2 Other optimisations.................................................................... 105
5.8.3 Optimising the steering controller............................................... 106
5.8.4 Optimising the speed ramps....................................................... 107
6 CAN Bus Protocol .........................................................108

Contents HG G-73650ZD
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6.1 Transmission Telegrams from Control Unit to PLC, the Wheels
and the Gyro .......................................................................109
6.1.1 Path Data Box ........................................................................... 109
6.1.2 Segment Search Box ................................................................. 110
6.1.3 Status Box................................................................................. 111
6.1.4 Error Box................................................................................... 112
6.1.5 Wheel Boxes ............................................................................. 116
6.1.6 Gyro Box ................................................................................... 118
6.2 Reception Telegrams from PLC, Wheels, Antennas, Gyro and
Sensor Fusion to the Control Unit ........................................119
6.2.1 Path data (target) Box ............................................................... 119
6.2.2 SPS Control Box........................................................................ 120
6.2.3 Remote Control Box .................................................................. 121
6.2.4 Wheel Box................................................................................. 122
6.2.5 Antenna Boxes .......................................................................... 123
6.2.6 Gyro Box ................................................................................... 124
6.2.7 Sensorfusion Boxes................................................................... 125
7 Feldbus Protocol ........................................................... 128
7.1 Tx Transmission Telegram Control Unit —> PLC ...................128
7.2 Rx Reception Telegram PLC —> Control Unit ........................132
8 USB Data Logging: Scope of the Data ........................... 136
8.1 Opening logged Data in Excel®............................................136
8.2 List of logged Parameters ....................................................137
9 Trouble Shooting........................................................... 148
10 Technical Data ..............................................................150
11 Appendix.......................................................................151
A Attributes........................................................................................ 151
B Radius Calculation with 16 Bit Resolution...................................... 152
C Configuration of the Ethernet Interface Parameters via SIO 2 ....... 153
D Firmware-Update via the USB Interface ........................................ 154
12 List of Figures ...............................................................158
13 List of Tables ................................................................161
14 Handbook Conventions..................................................163
15 Copyright and Terms of Liability .................................... 164
15.1 Copyright.............................................................................164
15.2 Exclusion of Liability ............................................................164

Contents HG G-73650ZD
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15.3 Trade Marks and Company Names.......................................164

Introduction HG G-73650ZD
English, Revision 04, Date: 28.10.2016 7
1 Introduction
The subject of this manual is the Navigation Controller HG G-73650ZD that enables
AGV (Automated Guided Vehicles) to follow virtual tracks. The following terms are
used synonymously throughout this document:
-Control Unit (as printed onto the hardware)
-navigation controller
-Vehicle Guidance Controller (VGC)
1.1 Tasks of the Navigation Controller
The navigation controller has the following tasks:
1. Determination of the current position via transponders, GPS or external input,
see section 2.3 on page 10
2. Reconstruction of the route to be driven (by means of segment files), see section
2.5 on page 20
3. Track Guidance (controlling the vehicle on a track), see section 2.6 on page 30
As the navigation controller is a very complex technical product the following pages
will first cover the various aspects of the vehicle's track guidance that have to be con-
sidered before we explain the subject areas of commissioning and configuration. The
following points will be explained later in this manual:
Basic information on positioning, track creation and track guidance
Hardware description, including displays and interfaces
Software description, including all menus of the web configuration
Commissioning
Protocol description, structure of the CAN- telegrams, Feldbus (external imple-
mentation on profinet, profibus, etc.)
Listing of data, which can be logged on an USB stick for analysis purposes
Trouble shooting
1.2 Intended Use
WARNING! The navigation controller is not a safe device! It may only be
operated in connection with a safety system!
Due to its design the navigation controller is designated for a wide scope of applica-
tions. It can only be applied for the track guidance of vehicles if the manufacturer or
the plant operator ensure that sensors for position detection are used that are suitable
for the requirements of that specific place and thus work fully (GPS e.g. is only suitable
for outdoor environments with the restriction that the GPS signals experience no inter-
ferences due to occlusions). Furthermore it is essential that all parameters, e.g. con-
cerning the vehicle's dimensions and functions as well as the position of the axles and

Introduction HG G-73650ZD
English, Revision 04, Date: 28.10.2016 8
wheels have to be entered with utmost accuracy. Consequently for new projects a
comprehensive testing of the settings with a jacked-up vehicle within a closed down
section of the plant is always recommended.
ATTENTION! As vehicles using the steering controller usually drive fully auto-
mated during their final / last implementation step, there is always
the risk of damages to the vehicles and the environment if any
incorrect parameters or faulty input signals are entered!
The vehicle manufacturer as well as the plant operator are obliged to operate with the
greatest care and to inform all persons either on the vehicle or in the danger zone sur-
rounding the machine about the risks involved. Furthermore all persons entrusted with
carrying out work within or close to the area of automated operation have to be in-
formed that the vehicle is driving autonomously.
1.3 Requirements / Options
-If you want to use the internal sensor fusion, at least one rotary encoder or any
other velocity or distance determining sensor has to be in operation. When rotary
encoders are directly connected to the steering controller please ensure that it is a
push/pull type with an output voltage of 5 to 25 V, two tracks perpendicular to
each other and a resolution of 0.1 to 1 mm / pulse. Using data telegrams on the
bus it is also possible to work with encoders to which this limitation does not
apply. For an improved accuracy or to achieve redundancy you can also use
Gyro HG 84300 (according to odometry).
-If a transponder positioning system is to be used, its antennas can be connected
via CAN bus. Alternatively or in connection with the transponder system you can
use a GPS system.
-When using the laser scanner HG 43600 two rotary encoders and two steering
encoders have to be connected directly to the navigation controller or deliver their
data via the wheel telegrams on the bus.
-Some steering servos and motor control units can be controlled / addressed
directly by the navigation controller so that a vehicle control system for each indi-
vidual application (e.g. PLC) is not absolutely necessary for each application.
However, in terms of monitoring, redundancy and customized adaptions a vehicle
control system is always recommendable for larger vehicles.
-If emergency stop functions are to be provided, a vehicle control system is man-
datory as the highest possible safety can only be achieved when both steering
controller and vehicle control system are installed.

Basic Principles of Track Guidance HG G-73650ZD
English, Revision 04, Date: 28.10.2016 9
2 Basic Principles of Track Guidance
2.1 Suitable and Unsuitable Vehicle Types
The range of particularly suitable vehicle types covers all vehicles that operate pre-
dictably and reproducibly. Several non-steered axles, trailers or vehicles with a center
pivot steering are not suitable.The wheel slippage has to be low and the wheels should
be hard to minimize the friction.
Figure 1 Example: Suitable vehicle types (selection)
The sketch below shows simplified versions of all the vehicles as three-wheelers, be-
cause this is the base vehicle model used by the navigation controller. The navigation
controller can also be used for vehicles where the steered wheel is not in the middle
(e.g. some fork-lift truck types).
Figure 2 Sketch: Suitable vehicle types
One fixed axle
particularly suited
e.g. fork-lift truck
Symmetrical steering
particularly suited
e.g. some heavy duty ve-
hicles
Two fixed axles
less accuracy and partly
rubbing, grinding wheels
e.g. large towing tractors
coordinate chassis
/ omnidirectional
vehicles
particularly suited
e.g. special vehi-
cles

Basic Principles of Track Guidance HG G-73650ZD
English, Revision 04, Date: 28.10.2016 10
2.2 System Composition
Figure 3 Block diagram system structure
Due to the strict separation of the track controller, sensor fusion and navigation system
and the smart interaction with the vehicle control, the navigation controller offers a high
degree of flexibility and is also suitable for monitoring safety-critical vehicle compo-
nents.
2.3 Position Determination with Sensor Fusion
The sensor fusion calculates the current position and the vehicle's orientation. The
sensor fusion provides the steering controller with the following data set (also referred
to as pose):
-X Position
-Y Position
-Speed
-Vehicle orientation
IO 1-3
A/B
A/B
Navigation Controller
Incremental
Encoder
(optional)
Incremental
Encoder
(optional)
Hardware Control Unit HG 61430
Gyro
HG 84300
(optional)
Transponder-Antenna
HG 98810 / HG 98820 /
HG 98850
(up to 4, optional)
GPS Antennas 1 & 2 (optional)
Track
Guidance
Controller
Vehicle PLC
Internal
Sensor fusion
Transponder
and/or GPS
IO 4
Central
Control
Unit
Narrow-band
RF Modem
(optional)
Narrow-band
RF Modem
(optional)
Steering Servo
Acceleration
(optional)
Break (optional)
Emergency Stop
(optional)
External
Sensor Fusion
e.g. Laser Scanner
(optional)

Basic Principles of Track Guidance HG G-73650ZD
English, Revision 04, Date: 28.10.2016 11
If the internal sensor fusion is used, the position of the vehicle is calculated from the
odometry, initialized and corrected by the transponder antenna and/or the GPS sys-
tem. The transponder antennas will then be connected via CAN bus. Additionally their
posi pulse has to be connected with IO-3 (see manual of the antenna). The optional
Gyro is connected via CAN bus as well and is intended to enhance the odometry.
NOTE! Since odometric calculations tend to be load-dependent the
installation of a Gyro is recommended.
If an external sensor fusion (determination of position and angle) shall be applied it
can be connected via the CAN Bus. The relevant protocol is described in chapter 6
from page 108. This may be e.g. laserscanner HG 43600. As long as they are compli-
ant with the CAN Bus protocol requirements it is possible to use other position- deter-
mination systems as well.
By the use of a short-term stable odometry in combination with an absolute position
sensor the advantages of both systems are united. The absolute position sensor ini-
tializes the odometric data and thus provides both the position as well as the vehicle
heading at every point. During operation the cumulative inaccuracies in the odometry
will be reset at those points where an absolute position is available.
In addition to the position and the steering angle the sensor fusion provides the speed
as well as an accuracy estimation. This estimation is based on the accuracy table (see
Table 47 on page 127). The table is structured in such a way that the error is small right
after e.g. a transponder has been passed over. With the distance traveled the error
tends to grow more rapidly, as the angle is also steadily worsening. So with every me-
ter travelled the value of the accuracy assessment is decreased by one position, i.e.
it moves one line upwards in the corresponding Table 47.
When using GPS technology the GPS system determines the position's estimated ac-
curacy in meters. If GPS and transponder antennas are used simultaneously the ac-
curacy estimation is defined by the system in use. Switching between systems can be
automated via accuracy thresholds or set manually via segment specific attributes.
2.3.1 The Odometry
The odometric system uses wheel rotations, the steering angle and/or a Gyro to deter-
mine the change in vehicle position and vehicle heading.
The odometry has the advantage to be highly accurate over short distances and to
supply the vehicle position at any time. The odometry has to be initilized at start-up.
However while traveling longer distances the system immanent errors accumulate.
This can cause considerable deviations.
2.3.2 Sensors for Navigation
2.3.2.1 Transponder Antenna
The transponder system outputs the position and the code of the transponder current-
ly located underneath the antenna. The position lateral to the direction of travel has an
accuracy between ± 5mm and ±20mm, depending on the antenna type (mostly its

Basic Principles of Track Guidance HG G-73650ZD
English, Revision 04, Date: 28.10.2016 12
size). Also depending on the antenna type the detection range is between ±125 and
up to ± 500mm, the reading distance varies between 50 - 200 mm. Possible antennas
are e.g. the Götting types HG 98810, HG 98820 and HG 98850.
The transponder position in direction of travel is only output as the posi pulse when the
center of the transponder antenna is crossing the transponder. When there is no tran-
sponder underneath the antenna, the antenna delivers no position. There may be at
most one transponder underneath the antenna at any given time. The parameters
of the transponder antenna are set via a RS 232 interface which is described in the
antenna manual.
Figure 4 Determination of antenna positions underneath the vehicle
The transponder antennas are 1.5 dimensional. That means that the relative transpon-
der position in direction to the long side of the antenna is measured. In direction of the
short antenna side only the crossing impulse (posi pulse) is available, which is gener-
ated when the transponder passes the center of the antenna. The navigation controller
associates a certain task with each antenna number:
Antenna 1: Front (if needed)
Antenna 2: Vehicle center, rotated by 90o(if needed)
Antenna 3: Rear
The simplest form is a set-up with a single antenna.
Vehicle X
Vehicle Y
Front
Antenna 1
Antenna 2
Antenna 3
Ant 3
Position X
Ant 3
Position Y
Ant 1
Position Y
Ant 1
Position X
Ant 2
Position X
Ant 2
Position Y

Basic Principles of Track Guidance HG G-73650ZD
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2.3.2.1.1 Single Antenna Evaluation — Calculation of the Position with one
Antenna
Figure 5 Single antenna: Placement
ATTENTION! In order to be able to calculate a position it is normally necessary
to detect more than one transponder!
The transponder antenna is able to determine the transponder position underneath the
antenna, however the direction of the antenna with regards to the transponder cannot
be determined. (exception: The transponder — a start transponder — can only be ap-
proached in one direction, e.g. at a transfer station). Thus it is necessary to cross two
transponders in order to define the position of the vehicle. The odometry additionally
measures the track between these two transponders. The transponder table enables
associating absolute positions with the individually measured points (transponders).
With the reading of two transponders it is then also possible to determine the direction
of the vehicle.
A fundamental disadvantage of the single antenna is that the calculated orientation of
the vehicle depends on the distance covered between the transponders. However, the
determination of this distance can only be as precise as the vehicle's odometry. Thus
the accuracy of the calculation not only depends on the antenna and the transponders
but also on the odometry. Subsequently this calculation is not as accurate as the mea-
surement accuracy guaranteed if two antennas read two transponders simultaneously.
For non-omnidirectional vehicles make sure that the antenna is always mounted as
close as possible to the fixed axle. If this installation proves to be difficult or isn't fea-
sible at all, the antenna has to be located as close as possible to the fixed axle in the
main direction of travel. The further away the antenna is from the fixed axle the less
accurate the measurement will be. (Lever arm, high transversal speed of the transpon-
ders in curves and reduced effective detection range in curves).
Vehicle X
Antenna 3
Vehicle Y
Front

Basic Principles of Track Guidance HG G-73650ZD
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Example
Figure 6 Properties of a single antenna set-up
Antenna properties:
The orange area of the antenna represents the range where max. one transponder
may be located. This area lies within a distance of approx. 50 mm around the
antenna casing.
The blue area is the antenna casing (here HG98820 180 mm x 360 mm)
The green area is the reception area of the transponder antenna (here approx.
±50 mm x ±125 mm)
If the thicker red line in the center of the antenna is crossed by a transponder, a
posi pulse will be triggered.
The example shows two possible mounting positions of the antenna on the vehicle.
The first position is 100 mm in front of the fixed axle (turquoise), the second one is
1500 mm in front of the fixed axle (magenta). In both cases the vehicle drives around
a curve with a radius of 500 mm. The example clearly shows that the first position is
much better than the second one:
-The antenna's effective reading range for the first position is still 224 mm, for the
second position the range is reduced to 78 mm.
-The reading accuracy of the first position is considerably higher. In both cases the
vehicle uniformly turns 4o(it turns with the same speed). The transponder read-
ings are displayed symmetrically to the posipulse. In position 1 the transponder is
read in a distance of 3,19 mm from the desired position (center of the antenna), in
position two with a reading error of 52,04 mm.
-As the transponder moves much faster through the reading area in position two
due to the bigger lever, the error rate, generated by the timing, will increase.
-Major corrective movements may lead to completely missing the transponder in
position two.
If it is not possible to install the antenna close to the fixed axle, e.g. on a fork-lift, the
following should be observed:
78,84 244,85
500
100
1500
4°
4°
3,19
52,04

Basic Principles of Track Guidance HG G-73650ZD
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-It should not be attempted to read transponders in tight turns. It is better to place
a pair of transponders with a distance of at least 0.5 m before and after the curve.
-Where curves are to be driven that are so long that transponders have to be read,
the radius has to be kept to the maximum possible and the speed should be as
lowered as much as possible.
-The transponder antenna has to be mounted as close as possible to the rear axle
(fixed axle or fixed roller).
For omnidirectional vehicles make sure that the antenna is mounted as close as pos-
sible to the center of the vehicle. Again the following applies: The more tilted the vehi-
cle moves the more restricted the measurement is. If the vehicle only drives in diagonal
direction a calculation cannot be performed at all, since the transponders are no lon-
ger crossing the antenna center and consequently no posi pulses are generated. For
each transponder crossing only one calculation is performed (posi pulse of the tran-
sponder).
2.3.2.1.2 Double Antenna Evaluation
Figure 7 Properties of a double antenna set-up
The double antenna set-up has the advantage that the vehicle orientation can be di-
rectly measured using the second antenna. To do so the transponders have to be laid
in such a manner that both antennas are simultaneously located above a transponder
each and that antenna 1 or 3 will trigger a posi pulse. Then the calculation is indepen-
dent from the odometry. Furthermore the accuracy, especially of the vehicle orienta-
tion, is much more precise in comparison with the evaluation of a single antenna. The
antennas should be mounted as far apart as possible. This means that small inaccu-
racies during positioning will only have a slight impact on the angle error. For each
transponder crossing only one calculation is performed (posipulse of antenna 1,3).
Vehicle X
Vehicle Y
Front
Antenna 1
Antenna 3

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2.3.2.1.3 The Triple Antenna Evaluation
Figure 8 Properties of a triple antenna set-up
In contrast to the single and double antenna set-up in this application all degrees of
freedom of the vehicle are measured directly. Calculations can be executed as long
as all antennas are positioned above transponders at the same time. This set-up also
allows the determination of the vehicle's position and orientation when driving diago-
nally. Antenna 1 and 3 determine the orientation and Y position, antenna 2 determines
the vehicle's X position (vehicle coordinate system). If only antenna 1 and 3 are located
above transponders, the position will be calculated when antenna 1 or 3 generate a
posi pulse (like when using a double antenna set-up).
2.3.2.1.4 Initialising the Transponder Sensor Fusion (Placing the Vehicle on
the Track)
There are several options for the initialisation of the transponder sensor fusion:
1. Single antenna set-up:
-The vehicle reads a special start transponder. The start transponder is a
normal transponder which can only be read with a certain orientation due
to constructional measures. This may be e.g. at a transfer station. The start
transponder is marked accordingly in the transponder list and the start
heading is recorded in 1/100o(s. 2.3.2.1.5 on page 17). A start transpon-
der is only evaluated as such directly after the system has been swit-
ched on, afterwards it is considered a normal transponder.
-The vehicle crosses several transponders. After the first transponder a
position cannot yet be calculated. After the second transponder the posi-
tion and heading can be calculated. After the third transponder the position
is confirmed and the accuracy is set to a good value provided the relative
position of the third Transponder corresponds with the positions of the pre-
vious ones.
2. Double antenna set-up: The start position is determined immediately with an
uncertainty of ½ of the antenna width when starting over two transponders.
3. Triple antenna set-up: With this set-up the start position is exactly determined
when initializing while the three antennas are placed above three transponders.
Vehicle X
Vehicle Y Front
Antenna 1
Antenna 2Antenna 3

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If the vehicle is also controlled by a driver (manual mode) it sometimes happens that
the transponders are not crossed directly anymore. This results in an increasing dete-
rioration of odometry accuracy. Since the system normally is not switched- off the only
remaining possibility for initialization for a single antenna system then is the second
alternative.
2.3.2.1.5 The Transponder List
The transponder list is a CSV file (values separated by a semi colon). It can be created
and edited with Microsoft® Excel® or other spreadsheet applications. The navigation
controller can import and export this list (configuration via web browser, see section
4.8.1 on page 85). Additionally the list can be displayed in the web browser, see sec-
tion 4.9 on page 86.
0;1;-2480;-4555;9000;0;0;1
1;2;-2462;-3171;0;0;0;0
2;46;6000;0;0;0;0;0
3;4336;9500;0;0;0;0;0
4;8012;031;6891;9000;127;127;1
These values have the following meaning for the navigation controller:
The first column displays the serial number of the transponder tags. The second col-
umn shows the corresponding transponder codes. The following two columns define
the position in X resp. Y direction in mm. In the fifth column the heading of the start
transponder is shown in 1/100o. Attribute 2 and attribute 3 are currently unused. At-
tribute 4 indicates a start transponder with a 1.
2.3.2.2 GPS
Currently positioning with GPS has not yet been implemented, but will be available at
a later date.
No. Code X Pos. Y Pos. Attribute 1 Attribute 2 Attribute 3 Attribute 4
0 1 -2480 -4555 9000 0 0 1
1 2 -2462 -3171 0 0 0 0
246 6000 0 0 0 0 0
34336 9500 0 0 0 0 0
48012 3031 6891 9000 127 127 1
Table 1 Definition of transponder list

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2.4 Coordinate Systems
Within the Control Unit different coordinate systems are in use. Segments and tran-
sponders refer to the local coordinate system (e.g. the coordinate system of the area).
All components of the vehicle refer to the vehicle coordinate system.
2.4.1 The Vehicle Coordinate System
Figure 9 Vehicle Coordinate System
The zero point (or origin) of the vehicle coordinate system is the point that is guided
along the segments.
-For omnidirectional vehicles the zero point can be chosen freely. Not each origin
makes sense, though, for the steering angles of the wheels to stay inside the pos-
sible values. When the vehicle drives curves in which the heading changes the
wheels that are farthest from the origin need high steering angles.
-For non-omnidirectional vehicles the origin has to be placed on a point that is
always moving in vehicle direction (e.g. the axis that is not steered).
The coordinate system is always positioned in the vehicle so that for 0osteering angle
and forwards movement the vehicle drives in positive X direction. Looking in positive
X direction the Y axis has its positive direction to the left. Also in positive X direction
the angle is 0oand grows anti-clockwise from 0 to 360o. The same is valid for the steer-
ing angle.
2.4.2 The Local Coordinate System
For the local coordinate system the same basic definitions are valid as for the vehicle
corrdinate system:
-The Y direction has its positive direction to the left when looking into positive X dri-
rection. Also in positive X direction the angle is 0oand grows anti-clockwise from 0
to 360o.
Vehicle Coordinate System
X
Y
Y
X
Local Coordinate System
0
o
0 - 360
o

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-When the GPS system is used either a local base station (origin) or the country
coordinate system are used. If no local base station is used the necessary GPS
correction data (wireless) have to be leased from a local provider.
ATTENTION! The geometer and GPS coordinate systems always have the
North as 0oand the angle turns clockwise. These coordinate sys-
tems have to be transformed into a X/Y coordinate system (X = N
and Y = -E).
If only Transponders are used for guidance the bearing of the coordinate system is ar-
bitrary. Keep in mind, though, that the origin is best placed close to the center of the
area for automatic driving. Otherwise the rounding errors of the calculations grow. The
maximum area that can be defined is ±10 km in X and Y direction.
If the country coordinate system is used an offset should be set so that the origin of
the country coordinate system is placed close to the center of the area for automatic
driving.
2.4.3 Characteristics of the Coordinate Systems
The basic GPS always uses an ellipsoid coordinate system since the globe of the earth
is flattened by its rotation. This however results in two disadvantages:
-Lines of longitude and latitude are impossible to measure with yard sticks.
-Plate tectonic means that the land masses are drifting several centimeters each
year inside the global coordinate system.
Thus country specific coordinate systems are used. Those coordinate systems drift to-
gether with the land masses and are almost flat. The GPS receiver performs the nec-
essary transformations automatically. The following example of a cylindrical
intersection explains some of the resulting quirks:
Figure 10 Cylindrical intersection of the earth globe for a flat country coordinate sys-
tem
For this method a 3ostripe of the surface of the earth is projected onto a cylinder. This
essentially results in two errors:
-The North heading is only fully valid in the middle of the stripe.
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