Parker TGSS User manual

True Ground Speed Sensor
TGSS
User Guide
MSG33-5005-IB/US
UG-TGSS-740051-201908-003

Parker Hannifin Canada
Electronic Controls Division
1305 Clarence Avenue
Winnipeg, MB R3T 1T4 Canada
office [phone]
Fax [phone]
http://www.parker.com/ecd
Copyright 2019 © Parker Hannifin Corporation. All rights reserved. No part of this work may be
reproduced, published, or distributed in any form or by any means (electronically, mechanically,
photocopying, recording, or otherwise), or stored in a database retrieval system, without the prior
written permission of Parker Hannifin Corporation in each instance.
Warning!
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS AND/OR SYSTEMS
DESCRIBED HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY
DAMAGE.
•This document and other information from Parker Hannifin Corporation, its subsidiaries and authorized
distributors provide product and/or system options for further investigation by users having technical expertise.
•The user, through its own analysis and testing, is solely responsible for making the final selection of the
system and components and assuring that all performance, endurance, maintenance, safety and warning
requirements of the application are met. The user must analyze all aspects of the application, follow applicable
industry standards, and follow the information concerning the product in the current product catalog and in any
other materials provided from Parker or its subsidiaries or authorized distributors.
•To the extent that Parker or its subsidiaries or authorized distributors provide component or system options
based upon data or specifications provided by the user, the user is responsible for determining that such data
and specifications are suitable and sufficient for all applications and reasonably foreseeable uses of the
components or systems.
•The Buyer and/or end-user will be solely responsible for final disposal of all products.

User Guide iii
The following table provides an overview of the changes made to this document
over the course of its publication history.
Revision
Description of Change
Rev. 001
First release of this document
Rev. 002
Update template and naming, 5/12/2017
Rev. 003
Update to meet RE-Directive requirements, 8/15/2019
Publication History

User Guide iii
Publication History ..............................................................................................................iii
Safety .....................................................................................................................................v
Safety symbols................................................................................................................................. v
General safety regulations............................................................................................................... v
Welding after installation..................................................................................................................vi
Construction regulations ..................................................................................................................vi
Safety during installation..................................................................................................................vi
Safety during start-up......................................................................................................................vii
Safety during maintenance and fault diagnosis..............................................................................vii
1. Product Description..........................................................................................................8
1.1. TGSS ........................................................................................................................................8
1.2. Compliances .............................................................................................................................9
2. Installation.......................................................................................................................10
2.1. Installation Guidelines.............................................................................................................10
2.1.1. Mounting Bracket.......................................................................................................11
2.1.2. Mounting Angle..........................................................................................................12
2.1.3. Mounting the TGSS to a vehicle................................................................................12
2.1.4. Line of sight clearance...............................................................................................13
2.1.5. Installation Validation.................................................................................................15
2.2. Performance Considerations ..................................................................................................16
3. Technical Specifications................................................................................................17
3.1. Microwave Output...................................................................................................................17
3.2. Speed Output Signal...............................................................................................................17
3.3. Radar-Present Output.............................................................................................................18
3.4. Connectors..............................................................................................................................18
4. Electrical Specifications.................................................................................................20
5. Environmental Specifications........................................................................................21
6. Mechanical Specifications .............................................................................................22
6.1. Dimensions .............................................................................................................................23
7. Appendix A......................................................................................................................24
7.1. TGSS Technical Overview......................................................................................................24
Contents

iv TGSS
Contents
7.1.1. Environmental ratings ................................................................................................24
8. Index.................................................................................................................................28

User Guide v
Do not perform the procedures in this manual unless you are experienced in the
handling of electronic equipment.
Contact the manufacturer if there is anything you are not sure about or if you have
any questions regarding the product and its handling or maintenance.
The term "manufacturer" refers to Parker Hannifin Corporation.
Safety symbols
The following symbols are used in this document to indicate potentially
hazardous situations:
Danger! Risk of death or injury.
Warning! Risk of damage to equipment or degradation of signal
When you see these symbols, follow the instructions carefully and proceed with
caution.
General safety regulations
Work on the hydraulics control electronics may only be carried out by trained
personnel who are well-acquainted with the control system, the machine, and its
safety regulations.
Follow the manufacturer's regulations when mounting, modifying,
repairing, and maintaining equipment. The manufacturer assumes no
responsibility for any accidents caused by incorrectly mounted or
incorrectly maintained equipment. The manufacturer assumes no
responsibility for the system being incorrectly applied, or the system
being programmed in a manner that jeopardizes safety.
Safety

vi TGSS
Safety
Do not use the product if electronic modules, cabling, or connectors are
damaged or if the control system shows error functions.
Electronic control systems in an inappropriate installation and in
combination with strong electromagnetic interference fields can, in
extreme cases, cause an unintentional change of speed of the output
function.
Welding after installation
Complete as much as possible of the welding work on the chassis before the
installation of the system. If welding has to be done afterwards, proceed as
follows:
Do not place the welding unit cables near the electrical wires of the
control system.
1. Disconnect the electrical connections between the system and external
equipment.
2. Disconnect the negative cable from the battery.
3. Disconnect the positive cable from the battery.
4. Connect the welder's ground wire as close as possible to the place of the
welding.
Construction regulations
The vehicle must be equipped with an emergency stop which disconnects the
supply voltage to the control system's electrical units. The emergency stop must
be easily accessible to the operator. If possible, the machine must be built so that
the supply voltage to the control system's electrical units is disconnected when the
operator leaves the operator’s station.
Safety during installation
Incorrectly positioned or mounted cabling can be influenced by radio
signals, which can interfere with the functions of the system.

User Guide vii
Safety
Safety during start-up
Danger! Risk of death or injury. Do not start the machine's engine
before the control system is mounted and its electrical functions have
been verified.
Do not start the machine if anyone is near the machine.
Safety during maintenance and fault diagnosis
Before performing any work on the hydraulics control electronics, ensure that
▪The machine cannot start moving.
▪Functions are positioned safely.
▪The machine is turned off.
▪The hydraulic system is relieved from any pressure.
▪Supply voltage to the control electronics is disconnected.
Safety during operation
RF exposure. To avoid possible eye injury, do not look directly into the
face of the radar sensor while it is in operation

8 TGSS
Product Description
1.1. TGSS
The true ground speed sensor (TGSS) uses the principle of Doppler shift to
determine the ground speed of the vehicle or other type of equipment. A
microwave signal that is transmitted out of the sensor, reflects off the target and is
received by the sensor. When the target (terrain) is moving relative to the sensor,
there is a change in the frequency of the reflected signal (Doppler shift). The
ground speed is calculated by measuring the change in frequency.
The TGSS is enclosed in a black plastic case, which is potted to cover the
electronics. The TGSS has a short cable terminated with a connector.
Figure 1: TGSS with Deutsch DT04-4P connector
Custom units with different cable lengths and connector types may be configured
for OEM customers. Contact your Parker Vansco representative.
1. Product Description

User Guide 9
Product Description
1.2. Compliances
This device complies with RSS 210 of Industry Canada. Operation is subject to
the following two conditions: (1) this device may not cause interference, and (2)
this device must accept any interference, including interference that may cause
undesired operation of this device.
"Ce dispositif se conforme à la norme CNR-210 d'Industrie Canada. Les
conditions suivantes s'appliquent à l'utilisation du dispositif:
(1) le dispositif ne doit pas causer d'interférence radioélectrique, et (2) le
dispositif doit être en mesure d'accepter toute interférence radioélectrique,
même si celle-ci est susceptible de compromettre son fonctionnement."
FCC ID: MGR740030A
This device complies with Part 15 of the FCC rules. Operation is subject to the
following two conditions: (1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that
may cause undesired operation.
Any changes or modifications not expressly approved by the party
responsible for compliance could void the user's authority to operate the
equipment.
Hereby, Parker Hannifin Corporation declares that the radio equipment type 740
TGSS is in compliance with Directive 2014/53/EU. The full text of the EU
declaration of conformity is available at the following internet address under
Product Support:
https://ph.parker.com/us/17616/en/tgss-true-ground-speed-sensors

10 TGSS
Installation
The TGSS is typically installed at a height of 0.3 to 1 meter (1 to 3 feet) above the
ground. The maximum height of installation is 1.22 meters (4 feet).
The sensor mounts to a bracket on the underside of the vehicle where the sensor
may be directed in either the forward or reverse direction.
Figure 2: Typical installation
2.1. Installation Guidelines
The TGSS 740 Radar measures motion relative to itself. It is important to prevent
unwanted motion in order to achieve optimal performance. The unwanted motion
could be of the TGSS unit, or of an object within the radar's line of sight.
2. Installation

User Guide 11
Installation
2.1.1. Mounting Bracket
The bracket should be at least 6.35 mm (¼”) steel and the length kept short to
minimize vibration.
6.35
[.250”]
MIN.THICKNESS
Figure 3: Mounting plate
The bracket dimensions that follow can be used as a guideline for the desired
bracket size. If it is necessary to increase the dimensions, consideration should be
given to increase the material thickness as well. This will help reduce the bracket's
susceptibility to vibration.
MIN 6,35IN[.250]
5X R 6,35
[.250]
178
[7.0]
178
[7.0]
267
[10.5]
35.0°
Figure 4: Recommended mounting plate dimensions
The TGSS has rubber shock absorber vibration mounts to reduce the effect of
machine vibration. The vibration mounts have an internal M6 thread, the
recommended installation torque is 5.4-7.3 Nm (48-65 in lbs).

12 TGSS
Installation
2.1.2. Mounting Angle
Any error in the mounting angle will directly affect the Doppler accuracy. At 35°,
an error of 1° is approximately a 1% error in speed measurement. Post installation
calibration should be done to remove errors due to bracket alignment tolerances
and vehicle levelness.
Figure 5: Installation angle
2.1.3. Mounting the TGSS to a vehicle
It is up to the original equipment manufacturer (OEM) to ensure the product is
securely mounted to the vehicle.
The following guidelines are related to physically attaching the TGSS to the
mounting bracket on a vehicle:
▪The TGSS should be secured with bolts in all 3 bolt holes using 6 mm Hex
Head bolts and locking washers.
The bolts should be tightened to 5.4-7.3 Nm (48-65 in lbs).
Appropriate length bolts are routed from the underside of the unit through the
mounting plate and tightened into the shock absorbers on the unit's base. The bolts
should engage the threads in the shock absorbers to a maximum depth of 6.35 mm
(¼").

User Guide 13
Installation
2.1.4. Line of sight clearance
It is important for the sight line of the radar beam to be as unobstructed as
possible. Interference with radar beam can lead to false or erratic speed readings.
The radar beam pattern is shown in Figure 5: Doppler line of sight. The smaller
region is the -3dB level and the larger region is the -10 dB level. These areas are
the relative sensitivity of the TGSS to motion.
The-3dB region is the area where the TGSS is most sensitive. This path must be
clear of any objects. Interference in this area will have a high likelihood of
degrading the performance of the product's ability to provide accurate speed
measurement.
The larger -10dB region is a lower sensitivity area. Objects that interfere in this
area have a potential to be an issue.
Figure 6: Doppler line of sight
Information
It cannot be known with certainty if there is a problem introduced from an
obstruction in the -10 db area, because there are too many other parameters
that come into play (ground texture, reflection coefficient of interference,
vibration level of interference, etc.). The best practice is to design the mount
so that there is plenty of clearance for the radar line of sight.

14 TGSS
Installation
The model is based on a mounting height of 1 meter. Any other height will
require that the radar beam model be stretched ratiometrically with the new
height. This is done by looking at the model as spherical coordinates and scaling
the radius proportionally to the 1 meter in the model.

User Guide 15
Installation
2.1.5. Installation Validation
After an installation location has been determined, the TGSS needs to be mounted
and evaluated to see if the Doppler signal is of acceptable quality.
The strength of the signal reflected back to the radar is determined mainly by the
texture of the ground. The more irregular the surface, the higher the return signal.
This is due to a greater reflecting area. On a very smooth surface, most of the
signal is reflected away from the radar.
2.1.5.1. Line of sight evaluation
With the vehicle stationary over a smooth surface, slowly sweep the engine rpm
over it’s range.
Monitor the TGSS speed output to see if any false speed is shown. If a false speed
reading occurs, there is either a line of sight or vibration issue.
2.1.5.2. Vibration analysis
In order to determine if the mounting has vibration, the vehicle should be
positioned over a rough surface. With the vehicle stationary, the engine rpm
should slowly be ramped through its range. Monitor the radar output speed to
determine if different rpm are causing a vibration induced speed.
If there is vibration induced speed, it can be from two sources:
1. Excess vibration motion of the radar.
2. Something vibrating within the radar's line of sight.
If the false speed occurs on a smooth surface as well, it is likely that there is a line
of sight issue.
If the problem has been determined to be due to excessive vibration on the radar
mount, the vibration source needs to be reduced or high vibration isolation is
required. Possible things to investigate are:
1. Add extra weight to the radar mount to increase its isolation from vibration.
2. Add vibration isolation to the mounting bracket installed on the vehicle.
3. Relocate the radar to an area of lower vibration.

16 TGSS
Installation
It is not required, but is suggested that the user interface that is
displaying the TGSS signal be configured to ignore any data when the
vehicle is stationary. This will prevent undesired speed readings caused
by external sources.
2.2. Performance Considerations
The TGSS is a K Band radar. There are many factors that may influence its
operation.
▪The further the ground is from the radar, the lower the return signal strength.
▪Smooth surfaces will reflect less signal back, resulting in lower return signal
strength
▪There is no return signal over standing water. Short term loss of signal from
small puddles is handled by the software. When driving over large areas of
water the output speed may become erratic or drop to zero.
▪External sources of motion can affect Doppler signal resulting in false speed
output when stationary or increased speed output signal variation when
moving.
Tall, blowing grass
Rain
Dripping water
Line of sight issue with vehicle installation (ie.hoses, tires, chassis
components)
Inadequate vibration isolation for the application
Flying debris from vehicle tires
Information
Even with an ideal installation, as outlined in section 4, the above conditions
can still result in undesired speed readings being displayed.

User Guide 17
Technical Specifications
3.1. Microwave Output
The output field strength generated by the TGSS is within the acceptability level
set by the FCC, IC, and EC.
Carrier frequency:
Standard: 24.125 GHz +/ 50 MHz
UK: 24.300 GHz +/ 50 MHz
Maximum Power: 100 mW, EIRP
Beam Width: 13° in the E -plane and 11° in the H -plane,
Side Lobes: nominal –17 dB
3.2. Speed Output Signal
The frequency of the output signal is proportional to the speed of motion. When
using the standard transceiver frequency of 24.125 GHz, the frequency will be
58.9Hz/mph at 35° mounting angle.
The equation for Doppler shift frequency (fd) is given by
where
V = target velocity (mph)
fo = transceiver frequency (Hz)
c = speed of light (671 x 106mph)
= angle between beam and path of target (degrees)
3. Technical Specifications

18 TGSS
Technical Specifications
The sensor has the capability of scaling the output frequency. The selection is
done during production by programming the scaling factor into the micro-
controller.
The selectable scales are:
1. 1.0 scaling - 58.9 Hz/mph (35° mounting angle, 24.125 Ghz)
2. .75 scaling - 44.2 Hz/mph, approximately 1 pulse per cm (35° mounting
angle, 24.125 Ghz)
The speed range of the sensor is 0.3 to 44 mph.
3.3. Radar-Present Output
This output signal is connected to the battery. Care should be exercised when
installing the unit into a system to limit the current on this output to less than
100 mA @ 12 V.
3.4. Connectors
There are 2 standard connectors available for the TGSS. For units that do not have
the Radar-present output the connector is an AMP Superseal 1.5 series, housing
part number 282105-1.
Figure 7: AMP Superseal 282105-1
AMP Superseal Connector Pinout
Pin
Function
1
Output Speed (square wave)
2
Battery (+9 to +16 Vdc)
3
Ground