MTS WIFT Mini Transducer Interface User Manual

be certain.

SWIFT® Mini Transducer Interface (TI) Product Information

100-214-316 B

Trademark information MTS, SWIFT, TestWare, RPC, and Remote Parameter Control are registered

trademarks of MTS Systems Corporation within the United States. These trademarks may be protected in other countries.

Microsoft, Windows, Wi ndows for Workgroups, Windows 95, and Windows NT are registered trademarks of Microsoft Corporation. Apple and Macintosh are registered trademarks of Apple Computer, Inc. UNIX is a registered trademark of The Open Group. LabVIEW is a registered trademark of National Instruments Corporation. All other trademarks or service marks are property of their respective owners.

Publication information

Manual Part Number Publication Date

100-214-316 A June 2009 100-214-316 B December 2011

Contents

Technical Support 5

How to Get Technical Support 5 Before You Contact MTS 5 If You Contact MTS by Phone 7 Problem Submittal Form in MTS Manuals 8

Preface 9

Before You Begin 9

Conventions 10

Documentation Conventions 10

Hardware Overview 13

Overview 14 Spinning Applications (Track or Road) 16 Non-Spinning Applications (Laboratory) 17

Design Features 18 Coordinate System 19 Specifications 21 Calibration 22 Transducer Interface 24

TI Front Panel 27

TI Rear Panel 28

Software Utilities 29

Introduction 30 TI2STATUS - Transducer Interface Status 31

Description of TI2STATUS Indications 31 TI2XFER - Transducer Interface Transfer 33 TI2SHUNT - Transducer Interface Shunt 35 Error Messages 38

SWIFT® Mini TI

Contents

Transducer Interface Setup 41

USB Driver Installation 42 Select a Zero Method 44

Calibration File Elements 45

Upload the Calibration File 47 Edit the Calibration File 48 Download the Calibration File 52

Installation 53

Transducer Interface Electronics Installation 54 SWIFT Sensor Setup for Data Collection 56 Quality of the Zero Procedure Verification 60 Data Collection 61 Road Simulator 63 Zero the Transducer Interface 64

Alternate zero procedures 67

Maintenance 71

Transducer Interface 71

Troubleshooting 73

Contents

SWIFT® Mini TI

Technical Support

How to Get Technical Support

Start with your

manuals

Technical support

methods

The manuals supplied by MTS provide most of the information you need to use and maintain your equipment. If your equipment includes software, look for online help and README files that contain additional product inform ation.

If you cannot find answers to your technical questions from these sources, you can use the Internet, e-mail, telephone, or fax to contact MTS for assistance.

MTS provides a full range of support services after your system is installed. If you have any questions about a system or product, contact Technical Support in one of the following ways.

www.mts.com The web site provides access to our technical support staff by means of an

onlineform:

www.mts.com > Contact MTS > Service & Technical Support button

E-mail tech.support@mts.com

Telephone MTS Call Center 800-328-2255

Weekdays 7:00 A.M. to 5:00 P.M., Central Time

Fax 952-937-4515

Please include “Technical Support” in the subject line.

Outside the U.S. For technical support outside the United States, contact your local sales and

service office. For a list of worldwide sales and service locations and contact information, use the Global MTS link at the MTS web site:

Before You Contact MTS

Know your site

number and system

number

SWIFT® Mini TI

www.mts.com > Global MTS > (choose your region in the right-hand column) > (choose the location closest to you)

MTS can help you more efficiently if you have the following information available when you contact us for support.

The site number contains your company number and identifies your equipment type (such as material testing or simulation). The number is typically written on a label on your equipment before the system leaves MTS. If you do not know your MTS site number, contact your sales engineer.

Example site number: 571167

When you have more than one MTS system, the system job number identifies your system. You can find your job number in your order paperwork.

Example system number: US1.42460

Technical Support

Know information from

prior technical

If you have contacted MTS about this problem before, we can recall your file based on the:

assistance

• MTS notification number

• Name of the person who helped you

Identify the problem Describe the problem and know the answers to the following questions:

• How long and how often has the problem occurred?

• Can you reproduce the problem?

• Were any hardware or software changes made to the system before the

problem started?

• What are the equipment model numbers?

• What is the controller model (if applicable)?

• What is the system configuration?

Know relevant

computer information

Know relevant

software information

For a computer problem, have the following information available:

• Manufacturer’s name and model number

• Operating software type and service patch information

• Amount of system memory

• Amount of free space on the hard drive where the application resides

• Current status of hard-drive fragmentation

• Connection status to a corporate network

For software application problems, have the following information available:

• The software application’s name, version number, build number, and (if

available) software patch number. This information can typically be found in the About selection in the Help menu.

• The names of other applications on your computer, such as:

– Anti-virus software – Screen savers – Keyboard enhancers – Print spoolers

Technical Support

– Messaging applications

SWIFT® Mini TI

If You Contact MTS by Phone

A Call Center agent registers your call before connecting you with a technical support specialist. The agent asks you for your:

• Site number

• Name

• Company name

• Company address

• Phone number where you can be reached

If your issue has a notification number, please provide that number. A new issue will be assigned a unique notification number.

Identify system type To enable the Call Center agent to connect you with the most qualified technical

support specialist available, identify your system as one of the following types:

• Electromechanical material test system

• Hydromechanical material test system

• Vehicle test system

• Vehicle component test system

Be prepared to

troubleshoot

Write down relevant

information

After you call MTS logs and tracks all calls to ensure that you receive assistance for your

• Aero test system

Prepare to perform troubleshooting while on the phone:

• Call from a telephone close to the system so that you can implement

suggestions made over the phone.

• Have the original operating and application software media available.

• If you are not familiar with all aspects of the equipment operation, have an

experienced user nearby to assist you.

In case Technical Support must call you:

• Verify the notification number.

• Record the name of the person who helped you.

• Write down any specific instructions.

problem or request. If you have questions about the status of your problem or have additional information to report, please contact Technical Support again and provide your original notification number.

SWIFT® Mini TI

Technical Support

Problem Submittal Form in MTS Manuals

Use the Problem Submittal Form to communicate problems with your software, hardware, manuals, or service that are not resolved to your satisfaction through the technical support process. The form includes check boxes that allow you to indicate the urgency of your problem and your expectation of an acceptable response time. We guarantee a timely response—your feedback is important to us.

Access the Problem Submittal Form:

• In the back of many MTS manuals (postage paid form to be mailed to MTS)

• www.mts.com > Contact Us > Problem Submittal Form button (electronic

form to be e-mailed to MTS)

Technical Support

SWIFT® Mini TI

Preface

Before You Begin

Safety first! Before you use your MTS product or system, read and understand the Safety

manual and any other safety information provided with your system. Improper installation, operation, or maintenance can result in hazardous conditions that can cause severe personal injury or death, or damage to your equipment and specimen. Again, read and understand the safety information provided with your system before you continue. It is very important that you remain aware of hazards that apply to your system.

Other MTS manuals In addition to this manual, you may receive additional manuals in paper or

electronic form. You may also receive an MTS System Documentation CD. It contains an

electronic copy of the manuals that pertain to your test system, such as:

• Hydraulic and mechanical component manuals

• Assembly drawings

• Parts lists

• Operation manual

• Preventive maintenance manual

Controller and application software manuals are typically included on the software CD distribution disc(s).

SWIFT® Mini TI

Preface

Conventions

DANGER

WARNING

CAUTION

Conventions

Documentation Conventions

The following paragraphs describe some of the conventions that are used in your MTS manuals.

Hazard conventions Hazard notices may be embedded in this manual. These notices contain safety

information that is specific to the activity to be performed. Hazard notices immediately precede the step or procedure that may lead to an associated hazard. Read all hazard notices carefully and follow all directions and recommendations. Three different levels of hazard notices may appear in your manuals. Following are examples of all three levels.

Note For general safety information, see the safety information provided with

your system.

Danger notices indicate the presence of a hazard with a high level of risk which, if ignored, will result in death, severe personal injury, or substantial property damage.

Warning notices indicate the presence of a hazard with a medium level of risk which, if ignored, can result in death, severe personal injury, or substantial property damage.

Caution notices indicate the presence of a hazard with a low level of risk which, if ignored, could cause moderate or minor personal injury or equipment damage, or could endanger test integrity.

Notes Notes provide additional information about operating your system or highlight

easily overlooked items. For example:

Note Resources that are put back on the hardware lists show up at the end of

the list.

Special terms The first occurrence of special terms is shown in italics.

Illustrations Illustrations appear in this manual to clarify text. They are examples only and do

not necessarily represent your actual system configuration, test application, or software.

Electronic manual

conventions

This manual is available as an electronic document in the Portable Document File (PDF) format. It can be viewed on any computer that has Adobe Acrobat Reader installed.

Preface

SWIFT® Mini TI

Conventions

Hypertext links The electronic document has many hypertext links displayed in a blue font. All

blue words in the body text, along with all contents entries and index page numbers, are hypertext links. When you click a hypertext link, the application jumps to the corresponding topic.

SWIFT

Mini TI

Preface

Conventions

Preface

SWIFT® Mini TI

Hardware Overview

Contents Overview 14

Spinning Applications (Track or Road) 16 Non-Spinning Applications (Laborator y) 17 Design Features 18 Coordinate System 19 Specifications 21 Calibration 22 Transducer Interface 24 TI Front Panel 27 TI Rear Panel 28

WEEE The Waste Electrical and Electronic Equipment (WEEE) symbol ( ) means

that the controller and its electronic parts must not be disposed of as unsorted municipal waste. Proper disposal is required by approved electronic waste collection agencies. Customers in the EC region who desire to return an end-oflife controller and its electronic parts are encouraged to contact your local MTS Systems Sales/Service Offices for instructions.

SWIFT® Mini TI

Hardware Overview

Overview

Data

S10-01

Track or Road

Laboratory Simulation

Overview

The MTS Spinning Wheel Integrated Force Transducer (SWIFT®) sensor is a light-weight, easy-to-use transducer that enables you to conduct faster, less expensive data acquisition and road simulation testing.

The transducer is designed for use on the test track and public roads, as well as in the test laboratory. It attaches to the test vehicle or an MTS Series 329 Road Simulator using an adapter and a modified wheel rim.

You can achieve excellent data correlation using the same transducer and vehicle on the test track or public road and on a road simulator. It is available in various sizes and materials to fit various vehicle and loading requirements.

Transducer Interface

(TI)

Additional

components

Parts replacement,

disassembly, and care

The TI provides power to the transducer and uses previously stored calibration values to convert the raw transducer signals from the bridge outputs and the encoder to three force outputs (Fx, Fy, Fz), three moment outputs (Mx, My, Mz) and an angle or angular velocity output. The force and moment outputs have a value of 10 V full scale, unless a different full-scale output is requested by a customer. The angle output is a 0 to 5 V sawtooth output. The angular velocity full scale can be configured in the calibration file.

Additional components that are supplied with your SWIFT sensor include transducer data cables, TI power cable, a SWIFT Transducer Interface Utilities CD or disk, and the calibration file. MTS can also provide a 12 V DC power supply for use in the test laboratory.

The SWIFT sensor assembly, Transducer Interface box, and the accessory components have no user serviceable parts. These components should not be disassembled other than as outlined in “Troubleshooting” beginning on page 73.

Hardware Overview

SWIFT® Mini TI

Overview

CAUTION

Do not disassemble the SWIFT sensor, Transducer Interface (TI) electronics, and accessory components.

The SWIFT sensor, TI electronics, and accessory components are not intended to be disassembled, other than as outlined in “Troubleshooting”.

Disassembling or tampering with these components may result in damage to the sensor, loss of watertight seal, and voiding of the warranty.

SWIFT

Mini TI

Hardware Overview

Spinning Applications (Track or Road)

Customer Supplied

Power Supply

Customer Supplied

Data Recorder

Transducer

Interface (TI)

Transducer Signals

Output

Signals

S10-02

(Battery or Vehicle power)

Spinning Applications (Track or Road)

The SWIFT sensor can be used for road load data acquisition (RLDA) applications:

• Durability

• Noise, Vibration and Harshness (NVH)

• Ride and Handling

• Tire Performance

The transducer is durable enough to withstand harsh road testing and data acquisition environments. The transducer is splash resistant and suitable for use in conditions where the test vehicle will encounter occasional standing or running water, or will be exposed to precipitation. However, it should not be submerged.

In a typical spinning application, the transducer is mounted on a modified rim of a tire on a test vehicle, as shown in the following figure. The Transducer Interface (TI), power supply, and data recorder can be securely mounted on a carriage rack. The TI box should be protected against environmental conditions (water and mud splashes and dust), and it should not be allowed to be immersed.

Hardware Overview

Spinning Application (Track or Road)

SWIFT® Mini TI

Non-Spinning Applications (Laboratory)

Power Supply (with 4

connections)

Customer-Supplied

Test Control System

Transducer

Interface (TI)

Transducer Signals

Output

Signals

PC Communication

S10-03

Non-Spinning Applications (Laboratory)

The SWIFT sensor can be fully integrated into the simulation process, since it is an optimal feedback transducer for use with MTS Remote Parameter Control (RPC) software. The transducer takes data at points where fixturing inputs are located rather than at traditional instrumentation points along the vehicle’s suspension. Using the SWIFT sensor saves you instrumentation time, and fewer iterations are required to achieve good simulation accuracy.

Measuring spindle loads allows engineers to generate generic road profiles. Generic road profiles are portable across various vehicle models, do not require new test track load measurements for each vehicle, and eliminate additional RLDA tasks.

Several of the six loads measured by the transducer directly correlate to the MTS Model 329 Road Simulator inputs.

The same transducers used to collect road data can be mounted directly in the wheel adapters of the MTS Model 329 Road Simulator. For durability testing, the SWIFT sensor can be used for iterations within the RPC process. The SWIFT sensor should then be removed for the durability cycles, to preserve its fatigue life. It can be replaced by an adapter plate, available from MTS, to duplicate the mass and center of gravity of the actual SWIFT sensor. If a SWIFT sensor is to be used during full durability tests, we suggest using the titanium model, which has a higher fatigue rating.

In a typical non-spinning application, a SWIFT sensor is mounted on a road simulation test fixture, as shown in the following figure.

Non-Spinning Application (Laboratory Simulation)

SWIFT

Mini TI

Hardware Overview

Non-Spinning Applications (Laboratory)

Design Features

Flexure isolation The SWIFT sensor has a very stiff outer ring and flexured beam isolation which

render it relatively insensitive to stiffness variations in matings with rims and road simulator fixtures.

Flexure isolation minimizes thermal expansion stresses. With flexure isolation, if the inner hub experiences thermal expansion the beams are allowed to expand out, resulting in lower compressive stress on the beams.

Thermal stability The entire sensor is machined from a solid, specially forged billet of high

strength titanium or aluminum. The absence of bolted joints permits an efficient transfer of heat across the sensor structure, minimizing temperature differentials in the gaged area.

The transducer is designed to accommodate the high temperature environments that occur during severe driving and braking events. Individual temperature compensation of each strain gage bridge minimize temperature induced variations in accuracy. Since minimal electronics reside on the SWIFT sensor, it can easily tolerate high temperatures. The temperature rating for the SWIFT sensor is 125° C (257° F) at the spindle hub.

Temperature compensation is done on each bridge for better performance in transient or non-uniform temperature occurrences.

Low hysteresis The SWIFT sensor has very low hysteresis, since the sensing structure is

constructed with no bolted joints. Micro slippage in bolted joints contributes most of the hysteresis in highly stressed structures. Hysteresis errors due to micro-slip at joints can contribute to unresolvable compounding errors in coordinate transformation of the rotating sensor.

Low noise The SWIFT sensor uses a slip ring for the transducer output signals. On-board

amplification of the transducer bridges minimizes any slip ring noise contribution.

Low cross talk The advanced design of the SWIFT sensor means that it has very low cross talk.

The alignment of the sensing element is precision machined. This alignment is critical to achieving minimum cross talk error between axes and minimum errors in coordinate transformation (from a rotating to a non rotating coordinate system). Any small amount of cross talk present is compensated by the TI.

Angle/Velocity

information

Angular position and angular velocity outputs are available from the TI when it is used in the spinning mode with the encoder. In non-spinning applications, accelerometers can be integrated into the transducer connector housing.

MTS does not supply any conditioning electronics for accelerometers. Ask your MTS consultant for more information about this option.

Hardware Overview

SWIFT® Mini TI

Coordinate System

Transducer

Interface

Output signals

±10 Volts

Angular

Position

Bridge

Outputs

S10-10

In the transducer, independent strain gage bridges measure forces and moments about three orthogonal axes. The signals are amplified to improve the signal-tonoise ratio. An encoder signal measures angular position, which is used to convert raw force and moment data from the rotating transducer to a vehiclebased coordinate system. The force, moment, and encoder information are sent to the transducer interface (TI).

Coordinate System

The TI performs cross talk compensation and converts the rotating force and moment data to a vehicle coordinate system. The result is six forces and moments that are measured at the spindle: Fx, Fy, Fz, Mx, My, and Mz. If desired, the TI can convert the forces and moments to represent a measurement that is offset from the spindle along the y-axis. A seventh (angular) output is available for tire uniformity information, angular position, or to determine wheel speed (depending on the data acquisition configuration).

Normally, the moments are referenced to the center of the transducer but can be offset to another location such as the center of the rim or tire patch.

SWIFT

Mini TI

Hardware Overview

Coordinate System

+Fz

+Mz

+Fx

+Fy

S10-09

Forces Acting on Rim-side of Transducer

Hub Adapter

Mounting Side

Rim Flange

Mounting Side

+Mx

+My

The coordinate system shown below was originally loaded into the TI settings by MTS. It uses the right-hand rule.

By default, the SWIFT coordinate system is transducer-based, with the origin located at the center of the transducer . Positive loads are defined as applied to the outer ring of the transducer.

• Vertical force (Fz) is positive up.

• Lateral force (Fy) is positive out of the vehicle.

• Longitudinal force (Fx) follows the right-hand rule, consistent with Fz and

Fy described above.

You can change to the MTS Model 329 Road Simulator convention (lateral load into the vehicle is always positive) or to any coordinate system by changing the polarities in the calibration file. The coordinate system can be moved along the yaxis by changing the y-axis parameter in the calibration file. For instructions on how to change the coordinate system polarities and offset, see “Transducer

Interface Setup” on page 41.

Hardware Overview

SWIFT® Mini TI

Specifications

Parameter Specification

Physical

Height Width Depth Weight Rack mounting kit

Environmental

Ambient temperature Relative humidity Protection

Transducer Interface

28 mm (1.100 in) 213 mm (8.375 in)

171 mm (6.750 in.)

0.907 kg (32 oz) Optional

0–50 °C (32–122° F) 0 to 90%, non-condensing IP64 (complete dust protection, projected water from all

directions)

Specifications

Power requirements

Input voltage Fuses

Power Consumption

Angular velocity

Encoder limit Processing limit

Time delay (encoder tick to main output stable)

Transd ucer cable length Analog outputs

Voltage

Capacitive load Current

Resolution

10–28 VDC Internal thermal, self-resetting

4 Watts maximum without transducer or encoder 6 Watts typical with transducer and encoder with 12 V DC

input.

2,200 rpm maximum 10,000 rpm maximum

150 µs (typical)

100 ft maximum

±10 V range† (force, moment, and angular velocity outputs) 0–5 V sawtooth (angle output)

0.01 µF maximum 2 mA maximum

16-bits

Communications

* Add 25.4 mm (1.0 in) for ground lugs. † Standard from MTS. Other full scale voltages can be evaluated and may be provided at special

request.

SWIFT

Mini TI

USB 2.0

Hardware Overview

Calibration

Each transducer is calibrated by MTS before shipment. The transducer and TI may be returned to MTS for repair and recalibration as required.

Calibration is performed at MTS on a special fixture that is capable of applying multiple loads to the transducer. During calibration, raw signals are measured. The calibration gains and cross talk compensation values are computed from this raw data. These gains are recorded in a calibration file.

A unique calibration file is supplied for each transducer. The serial number of the TI associated with the transducer is listed at the top of the calibration file. A label with the serial number of the TI box (and the SWIFT sensor with which it was originally calibrated) is attached to the back of each TI box.

The calibration file is loaded into the TI non-volatile memory by MTS before the transducer is shipped. A copy of the file is also provided on a disk.

MTS verifies the calibration by applying loads to the transducer, measuring the main outputs and checking for accuracy. Final calibration reports are provided with each transducer.

Note For SWIFT transducers designed to operate with the previous generation

low-profile TI, shunt cables A and B must be connected prior to performing a shunt check.

Shunt verification Shunt verification is good for verifying the SWIFT electrical system. A shunt

verification that fails should be investigated because the calibration will likely be affected. However, a shunt passing does not guarantee the system load accuracy so other checks should be done to verify load accuracy.

At the end of the calibration process, a shunt check is performed. During a shunt check, a resistance is introduced into the bridge circuit. The difference between the shunted and unshunted voltage is the delta shunt reference value for each bridge. That value is saved in the calibration file, which is downloaded from a PC or laptop computer and stored in non-volatile memory in the TI.

At any time afterward, pressing the Shunt button on the front of the TI causes each of the strain gage bridges to be shunted in sequence, and the measured shunt voltage (delta shunt measured value) is compared to the reference value.

An acceptable tolerance range is also loaded into the TI memory during system calibration. One tolerance value is used for all bridges. This value is loaded as a percentage of allowable deviation from the delta shunt values. For example, if the FX1 bridge has a shunt delta reference value of –3.93, and the tolerance is set at 2 (percent), the acceptable range for the measured value would be –3.85 to –4.01.

Hardware Overview

SWIFT® Mini TI

Calibration

When you press the Shunt button, the associated Shunt indicators toggle while the shunt is in progress. As the TI automatically switches through the series of bridges, it verifies that the outputs are within the accepted tolerance range. If all bridge shunt values fall within the tolerance range, the Shunt indicators on the front panel will go off (after several seconds). If any bridge fails the shunt test, the red, fail indicator lights, indicating that the shunt calibration has failed. The fail indicator remains lit until a shunt check passes or until you cycle power off and on. Use the TI2STATUS utility to get more detailed information about the shunt failure.

ShuntTolerance=2 FX1ShuntDeltaRef=-1.379 FX2ShuntDeltaRef=-1.386 FY1ShuntDeltaRef=-1.381 FY2ShuntDeltaRef=-1.378 FY3ShuntDeltaRef=-1.382 FY4ShuntDeltaRef=-1.381 FZ1ShuntDeltaRef=-1.380 FZ2ShuntDeltaRef=-1.380 FX1ShuntDeltaMeas=-1.378 FX2ShuntDeltaMeas=-1.386 FY1ShuntDeltaMeas=-1.380 FY2ShuntDeltaMeas=-1.379 FY3ShuntDeltaMeas=-1.382 FY4ShuntDeltaMeas=-1.382 FZ1ShuntDeltaMeas=-1.385 FZ2ShuntDeltaMeas=-1.382

Manual shunt

verification

Example of Calibration File Shunt Data

The above example shows shunt data from the calibration file. This data can be transferred, using the TI2XFER program, from the transducer interface memory to a computer or from a computer to the transducer interface memory. Note that items marked ShuntDeltaMeas are uploaded from memory, but not downloaded from the computer.

For more information on TI2XFER, see the chapter, “Software Utilities”.

You can check the system at any time by pressing the Shunt switch (described earlier). The shunt verification checks a portion of the system by applying an electrical offset at the input. Shunt verification can be used as a troubleshooting tool; failing the shunt verification raises the possibility the system is not calibrated. You can set the tolerance values for each TI by editing the calibration file. For instructions, see “Transducer Interface Setup” on page 41.

SWIFT

Mini TI

Hardware Overview

Transducer Interface

or Angular Velocity signal (+/- 10 V)

Transducer Interface

The TI performs cross talk compensation, transforms the loads from a rotating to a non-rotating coordinate system, and produces an analog output signal suitable for most data recorders.

Cross talk

compensation

Cross talk occurs when a force is applied to one axis, but a non-real force is measured on another axis. The SWIFT sensor design has very low inherent cross talk. The TI compensates for cross talk by subtracting cross talk values measured during calibration.

Signal conditioning The TI is specifically designed to be used for both spinning and non-spinning

applications. The TI performs signal conditioning and communications functions. The output from the TI is a high-level signal suitable for input into a multichannel data recorder or an MTS Automated Site Controller (ASC).

The TI transforms eight inputs (amplified bridge signals) into three forces and three moments by the following process:

• Applying a zero offset and scaling the signals

• Using a geometric matrix to transform the signals into three forces and three

moments in the transducer reference frame

• Using a cross-coupling matrix calculation to scale and sum the individual

signals into each output

• Using an offset matrix to shift the coordinate system along the y-axis

• In spinning applications, using a rotational transformation to put the forces

and moments into a stationary reference frame

Hardware Overview

SWIFT® Mini TI

Transducer Interface

Coordinate

System

Oset

Matrix

The TI conditions the transducer signals, producing seven analog output signals proportional to the following values:

• Longitudinal force (Fx)

• Lateral force (Fy)

• Vertical force (Fz)

• Overturning moment (Mx)

• Driving/Braking moment (My)

• Steering moment (Mz)

• Angle (θ) or Angular Velocity (ω)

Analog signals The force, moment, and angular velocity signals are output from the TI in the

form of ±10 V acquisition systems.

The angle output is an analog voltage that is proportional to angular position. At 0° the output is 0 V. At 360°, the output is 5 V.

full scale analog signals. These signals can be used by most data

SWIFT

Mini TI

1. Standard from MTS. Other full-scale output voltages can be evaluated and may be provided at special request.

Hardware Overview

Transducer Interface

0 360°

0° 360°

Angle

Output

1 rev = 360°

S20-10

The angle output for a tire rotating at constant velocity can be represented by the following illustration:

Although you may not routinely use it, the angle output information is available for tasks such as tire uniformity testing and troubleshooting.

If using the sawtooth angle output for analysis, care should be taken when setting the data acquisition to avoid filter-induced ringing or attenuation of the sawtooth output.

High-Resolution

Velocity Algorithm

The Mini TI has two algorithms for calculating angular velocity. The high resolution algorithm provides a much cleaner signal, but requires a minimum Mini TI FPGA version of 15. For the high resolution algorithm, the plot below shows the expected ripple of the angular velocity signal as a function of actual angular velocity.

The low resolution velocity algorithm produces significantly larger ripples on the angular velocity signal. These ripples can be reduced by enabling a filter at the input of data acquisition system. For more information on the angular velocity output option, contact MTS.

Communications The TI uses USB 2.0 for communication. The MTS supplied USB drivers must

be installed on each computer you connect to the TI.

Hardware Overview

SWIFT® Mini TI

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