GPS

• 24 Satellites

• 20km Orbits

• Owned by US Military

• No charge for use

• 100% world coverage

GPS

Receiver measures delays to satellites

Calculates distance to each satellite

Position of satellites already known

Minimum of 3 satellites for position

Triangulation gives 3D position

More satellites, more accuracy

Primary measurement = Position

Secondary measurement = Doppler shift

Triangulation

Doppler Shift

GPS Speed

0

10

20

30

40

50

60

70

80

1 68 135 202 269 336 403 470 537 604 671 738 805 872 939

GPS Speed

Speed from position

Doppler speedDoppler speed

0

10

20

30

40

50

60

70

1 83 165 247 329 411 493 575 657 739 821 903

Doppler speed

What can you measure?

GPS derived measurements

• Non slip Velocity

• Position

• Height

• Distance

• True X,Y acceleration

• Side slip angle

• Radius of turn

What are the advantages?

The advantages of using GPS

• Small

• Lightweight

• Quick to fit

• Versatile

• Low power

• Robust

• Discrete

Used almost anywhere

• All weather conditions

• Independent of surface

• Anywhere in the world

GPS accuracy

Other sources of Error

Hard Surface

Direct

Sig

nal

Ref

lect

ed S

igna

lReflected Signal

Satellite

GPSAntenna

Accuracy

• Velocity ±0.1km/h

• Distance ±0.05%

• Acceleration 0.5%

• Absolute position 3m

With Selective

Availability • X,Y position within 100m

Without Selective Availability • X,Y position within 3m

Calibration • Doppler simulator

• 12 satellite channels

• Repeatable

• Different simulations

• Constant speed

• Brake test

• High g cornering

• UKAS calibrated

Increasing Position Accuracy

Differential GPS

• Fixed base station at known position

• Measures distances to satellites

• Corrects readings based on known position

• Corrections sent via radio or satellite

WAAS DGPS Coverage

Accuracies

• No DGPS 3m

• WAAS 1.5 m

• Local DGPS 0.5m

RTK GPS • Real Time Kinematic

• Fixed base station

• Limited baseline length <5km

• Dual frequency, L1 & L2

• Corrections sent via radio

• 1cm XY accuracy, 2cm Z accuracy

• Track mapping

• ACC testing – distance between two vehicles

Sample rate

Sample rates available

• 1 Hz - route plotting only

• 5 Hz - general performance

• 20 Hz - brake testing

• 100Hz - transients/dynamics

Sample rate comparison

0

20

40

60

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140

1 65 129 193 257 321 385 449 513 577 641 705 769 833 897 961 1025 1089 1153 1217 1281

Samples

km/h

5Hz

20Hz

100Hz

Sample rate comparison

0

20

40

60

80

100

120

140

1 14 27 40 53 66 79 92 105 118 131 144 157 170 183 196 209 222 235 248 261 274 287 300 313 326

Samples

km/h

5Hz

20Hz

100Hz

100Hz sample rate

• Lateral aquaplane tests

• Lane change manoeuvre

• 2 second test

• 20Hz - 40 samples

• 100Hz – 200 samples

Suitable for Transients

Formula one car

Maximum yaw rate =

150 degrees per second

100Hz sample rate

Suitable for very high dynamics

Existing customersMIRAMillbrookIdiadaBosch TUVVisteonBPContinental Teves (Auburn Hills USA & Germany)US ArmyVickers defenseQinetiQRoush IndustriesHaldexJatcoPalmersportMartin Baker (Ejection seats)Rod Millen special vehiclesBorgWarner AutomotiveInternational Truck and Engine Corporation Transport Canada PMG TechnologiesChip Ganassi RacingTARRCTest World - FinlandWindjet Speed Record Project W S Atkins Rail Helsinki UniversityAP Hydraulics

Car and DriverPopular Science AutomobileEVO AutoexpressAutocar (UK)Autocar (NZ)Autocar (India) Autocar (Greece)Autocar (Czech)Option Magazine (Japan)What CarFast FordCar and Car ConversionsFast BikePerformance BMW Bike Magazine BBC Top Gear TVITV Pulling PowerMotorcycle newsMotor Magazine (Norway)Tekniikan Maailma-Magazine (Finland)Overdrive (India)Duke VideoDriven(Thailand)

DunlopGoodyearMichelinContinental Tyres Bridgestone Firestone Kumho tyres (Korea & UK)ContinentalNexenNokian

FordGMDaimler ChryslerMercedesBMWFerrariLamborghiniToyotaHondaVolvoSaabNissanRenaultYamaha Aston MartinHyundaiProtonIvecoAMGLand Rover Triumph MotorcyclesHarley DavidsonAmerican SuzukiFord RacingVolvo Penta Renault F1 teamTVS Motorcycles (India) LML Motorcycles (India)

Applications

• Distance is derived from velocity & time

• Accuracy ±5cm

• Very repeatable

• Also measure Longitudinal G & drift

• Brake assist development

Brake testing

• Traction control development

• Time between two speeds

• ¼ mile time and terminal speed

• Vmax

• In gear times

Performance testing

• Lap time using virtual gates

• Split times

• Lateral G from radius & speed

• Driver line

Circuit & driver analysis

Multifunction display

• Accel 0-60,50-70 etc

• Lap times/splits

• Printer function

• Brake stop, 100-0 etc

• Multiple test profiles for quick and easy live results.

CAN modules

Analogue inputs• 24 bit A-D

• 8 channels

• 20Hz to 100Hz

• ±100mV to ±50V

• Opto-isolated, differential

• CAN output

• Fully configurable

Thermocouple inputs• 24 bit A-D

• 8 channels

• -50 to +1200 degrees

• 0.1 degrees

• CAN output

• Fully configurable

Frequency/pulse inputs

• 4 Frequency inputs

• 0.5 – 25Khz

• Pulse counting

• TTL or inductive inputs

• CAN output

• Configurable

• Calculate wheelslip

Vehicle CAN Interface

• 16 CAN channels

• Fits any CAN bus

• Fully configurable

• CAN input/ CAN output

• OEM Data sets available

Vehicle CAN Interface• Mercedes

• BMW

• Audi

• Volkswagen

• Porsche

• Ferrari

• SAAB

• Vauxhall

• Jaguar

• Fiat

• Alfa

• Renault

• Citroen

• Peugeot

• Ford

YAW SENSORYAW SENSOR

•Yaw rate range ±150°/s •Acceleration range ±1.7g in each axis•Internal temperature compensation•Yaw rate resolution 0.01°/s•Acceleration resolution 1mg•CAN Bus interface

The YAW02 is designed for use with VBOXII, VBOX-III or as a stand-alone sensor with simple connection and configuration via the CAN bus interface.

INERTIAL MEASUREMENT UNIT ( IMU)INERTIAL MEASUREMENT UNIT ( IMU)

• Yaw, Pitch and Roll rate range ±150°/s• Acceleration range ±1.7g in each axis• Internal temperature compensation• Yaw, Pitch and Roll rate resolution 0.01°/s• Acceleration resolution 1mg •CAN Bus interface

The IMU01 is designed for use with VBOXII, VBOX-III or as a stand-alone sensor with simple connection and configuration via the CAN bus interface.

VBOX Slip Angle Sensor

• Velocity

• Position

• Distance

• X & Y Acceleration

• Slip angle

• Pitch or Roll angle

• Lateral velocity

• Yaw rate

By closely coupling two 20Hz GPS engines, the VBOX Slip Angle Sensor can measure the following:

How does it work?The two antennas are placed at an exact distance apart

How does it work?The angle the vehicle is pointing is calculated using trigonometry.

How does it work?The direction the vehicle is travelling is the Course over Ground of the primary antenna

How does it work?The slip angle is the difference between the two

Where is the slip measured?The slip angle measured at the primary antenna

Where can the antennas be placed?The primary antenna is placed anywhere, as long as it is a known distance from the secondary antenna.

Any misalignment to straight ahead is calibrated out in a simple operation, allowing the antennas to be placed in any orientation.

If the antenna is not fixed to the roof, an antenna with an internal ground plane must be used (as shown).

How good is the pitch measurement?

In the example above, the small pitch variations (±0.6)º during a gear change can be clearly seen.

How can I measure Roll?Place the antennas at 90º to the direction of travel, Slip and Roll are now measured.

What are the accuracies?The accuracies depend on the separation between the antennas:

• 0.5 m separation gives 0.5º

• 1.0m separation gives 0.25º

• 2.0m separation gives 0.1º

What kind of tests can it be used to measure ?

The 20Hz sample rate gives plenty of detail even in a very fast manoeuvre such as a violent lane change shown above, note the very large yaw rate and jerk rate.

Does it need constant alignment ?

The Slip Angle Sensor can be used indefinitely during vehicle testing without any need for alignment due to the absolute measurement of heading obtained using the two

antennas

What outputs are available?

• 2 x 16 bit analogue outputs

• 2 x 24 bit digital outputs

• CAN output

• RS232 output

The Slip Angle Sensor can be connected to a VBOX which will then log all the measured parameters.

Recent Product ReleasesRecent Product Releases

Differential Base Station

• Standard RTCM output• Integrated radio transmitter• 25 Position memory• Self survey mode• Battery or external power• Supplied with radio receiver• Rugged IP64 Enclosure

CAN Display

• Compact Size• Simple graphical interface• Use standard DBC database

files• Display raw CAN data or

database signals• Automatically detects CAN bit/

s• Scan CAN Bus for lists of all

identifiers

Recent Product ReleasesRecent Product Releases

Recent Product ReleasesRecent Product Releases

File Manager

• Simple graphical interface• VBOX filenames can be

configured by the user• Unwanted files can be

deleted after each test• Graphical speed display• Set logging modes without

laptop

Windows s/w

• Flexible graphs

• Circuit plots

• Results tables

• Live Windows

• Live results

Live Windows

Report generator

GPS• Extremely versatile

• Accurate

• Very convenient

• GPS now accepted as a means of measuring speed and distance by an increasing number of automotive companies.

• The VBOX is used by BMW, Daimler Chrysler, GM, Ford, Michelin, Goodyear, Bosch, Visteon, Idiada, MIRA etc.

• More satellites and more processing power means GPS is only going to get better.