University at Buffalo's NEES Equipment Site Instrumentation and Data Acquisition Scot Weinreber* Senior Instrumentation Specialist Department of Civil, Structural and Environmental Engineering
Web Information resource http://nees.buffalo.edu http://nees.buffalo.edu/docs/labmanual/seesllabmanual.pdf
Instrumentation and Data Acquisition
Overview Instruments Calibrations Data acquisition systems User requirements
Instruments Standard Instrumentation Motion Acceleration Accelerometer (non-reference) Acceleration - MEMS Accelerometers Array Displacement - Potentiometer Displacement - String pot Displacement Temposonic (sonic transducer) Displacement / Rotation - LVDT / RVT Load Uniaxial load cell Strain gage Special Instrumentation Krypton 5 Component load cell
Accelerometer Standard Instruments Potentiometer String pot RVDT Uniaxial load cell Temposonic Strain gage
Special Instruments Krypton Camera 3 D displacement measurement with 1 LED 6 D displacement measurement with 3 LEDs 5 Component load cell Axial load Shear in 2 directions Moment in 2 directions
Krypton video system System overview Hardware Specifications and limitations 3D field of view
Krypton camera operation The K600 camera system is a 3D measurement system based on three linear CCD cameras. By triangulation the position of an infrared LED in space is calculated. This can be a static or a dynamic measurement. The field-of-view of the camera is determined by the overlap area of the three linear CCD-camera s in the camera unit, resulting in a pyramidal volume. The top angle of the pyramid is 34 (+17 / -17 ): rule-ofthumb says that the lateral visibility limit (measured from the symmetry plane of the camera) is half the distance from the camera.
Krypton hardware controller camera LED strober Space probe LED
Resolution : 0,002 mm at 2,5 mm Noise (1s) : 0,010 mm Accuracy : Single Point : 0,060 mm Volumetric : 0,090 mm + 0,010 mm/m The indicated measurement uncertainty is expressed for a confidence level of 95%, according to the ISO 10360 II, VDI 2617 and ANSI / ASME B89.1.12M standards for acceptance of CMMs. Acquisition frequency : Important notice: The K400 camera system can not be used for dynamic measurements. The measurement frequency for static measurements is set to 10Hz. K600 CAMERA UNIT Field-of-view: 17 m³, distributed into three accuracy zones as follows: Resolution : 0,002 mm at 2,5 mm Noise (1s) : 0,010 mm Accuracy : Zone Volumetric Accuracy (± 2s) Single Point Accuracy (± 2s) I 90mm + 10mm/m 60mm + 7mm/m II 90mm + 25mm/m 60mm + 17mm/m III 190mm + 25mm/m 130mm + 17mm/m The indicated measurement uncertainty is expressed for a confidence level of 95%, according to the ISO 10360 II, VDI 2617 and ANSI / ASME B89.1.12M standards for acceptance of CMMs. Acquisition frequency : depends on the number of LED s: 1 LED : 1 khz 1 frame (3 LEDs) : 800 Hz 2 frames (6 LEDs): 400 Hz
First floor braces with Krypton Strobers LEDS
3D Krypton field of view LEDs in view ( green ) LED out of view ( red)
From LAB MANUAL
5 Component Load cells Load cell Overview Load cell wiring Load cell design specifications Capacity nomogram for Load cell cross section Example calibration data
5 Component Load cell Top View B A Y- Axis X-Axis C D Axial Shear Moment
5 Component Load cell wiring From LAB MANUAL
From LAB MANUAL
From LAB MANUAL
Calibrations
Calibration methodology Calibration Calibration is the process of finding the relation between the mechanical quantity measured and the electrical or digital output of the instrument. Calibration process applies an excitation producing a known mechanical output an measures the electrical / digital effect. Requires reference instrument or excitation. Calibration for individual experiments Calibrations for accelerometers, string pots, temposonics, strain gages, RVDTs, and independent uniaxial load cells ( not on actuators ) are performed for each test. The instruments are calibrated using traceable standards and using the wires and data acquisition channels for that experiment. This corrects for impedance changes over line lengths. Annual calibrations Load cells associated with actuators are either calibrated by MTS (NEES), or calibrated by a reference standard and are matched with a conditioner and cable. Special calibrations The 5 degree load cells are calibrated annually, and have matched pigtail cables and either a matched conditioner or matched Pacific channels. These calibrations require an experimental setup that involves several instruments simultaneously and will be described latter in detail.
Calibration Overview 5 Component Load cells Accelerometers String pots Strain gages Krypton Future calibration equipment
5 Component Load cell Calibration techniques Low capacity Large capacity
Example Calibration
Flip calibration Accelerometer calibration CALIBRATING THE ADXL202E/ADXL210 +1 G -1 G The initial value of the offset and scale factor for the ADXL202E will require calibration for applications such as tilt measurement. The ADXL202E architecture has been designed so that these calibrations take place in the software of the microcontroller used to decode the duty cycle signal. Calibration factors can be stored in EEPROM or determined at turn-on and saved in dynamic memory. For low g applications, the force of gravity is the most stable, accurate and convenient acceleration reference available. A reading of the 0 g point can be determined by orientating the device parallel to the earth s surface and then reading the output. A more accurate calibration method is to make measurements at +1 g and 1 g. The sensitivity can be determined by the two measurements. To calibrate, the accelerometer s measurement axis is pointed directly at the earth. The 1 g reading is saved and the sensor is turned 180 to measure 1 g. Using the two readings, the sensitivity is: Let A = Accelerometer output with axis oriented to +1 g Let B = Accelerometer output with axis oriented to 1 g then: Sensitivity = [A B]/2 g
String pot calibration The string pot is placed on the fixture, magnets Locked into the washers, and the string pot line fully retracted. The first reading for the instrument is taken, then the line is Placed in the slotted post for the second reading.
Strain Gage Calibration Precision resistor Zero strain reading Rc Rg Rg Excitation Rg Rg Signal Shunt Calibration factors Rg Fg Rc s gage resistance gage factor shunt resistance microstrain value Loaded strain reading s = ( Rg *1e6) (( Fg*( Rc+ Rg))
Krypton Calibration Camera Calibration The reference bar The reference bar is a temperature-independent, carbon fiber bar, ending in two cones. When measuring the distance between these cones, and comparing them with the nominal distance, the software can estimate and compensate environment influences on the camera. Space probe Calibration ProbeCheck ProbeCheck is a software package that verifies if your Space Probe operates as it should. It tests the serial communication, the colored LED s, the buttons and the internal speaker. Should you experience any problems when ProbeCheck gives no problems, you ll have to search the problem in an erroneous configuration, or a software problem.
Krypton calibration coordinate set up Line: a straight line through at least two points Origin: N/A Direction: positive from the first point towards the last point Tolerance: applicable when more than 2 points are fitted Intersect two or more elements: this operation intersects two or more geometric elements and generates the intersection element. The type of the element depends on the intersecting elements Coordinate system Using the measured lines the performing the intersection for the origin the coordinate system can be generated with the 2 measured lines and the intersection point
Future calibration equipment Accelerometer calibration Displacement calibration
Data Aquisition
Data Acquisition Systems Instrument / Data flow Internal conditioning External conditioning Analog input only systems ( No signal conditioning) MEGADAC 128 channels analog input Labview 32 single ended (16 differential) analog input External Conditioning Analog input (systems with signal conditioning) Pacific 308 conditioned and filtered channels, 8 Thermocouple channels Digital systems Krypton Video systems Camera Video Still
Internal conditioning Instrument Patch panel Patch panel DAQ patch panel amplifier filter Wire A/D Excitation voltage 6032 DAQ card HUB GPIB interface PC Pacific Data
External conditioning Instrument Patch panel DAQ patch panel amplifier filter Patch panel Wire Conditioner Excitation voltage 885 HUB GPIB interface PC MEGADAC Data
MEGADAC Data Acquisition System Hardware ( MEGADAC ) Chassis Cards ( type and quantity ) Connections Transducer connections Location and interfacing Patch panel
MEGADAC Data Acquisition System MEGADAC 5414 AC
AD 885 SH-1 8 analog input channels
AD 684-1 4 channels with conditioning
AD 682-1 2 channels with conditioning
AD 5884TD 8 thermocouple channels
MEGADAC channel availability
MEGADAC interconnect system Main access panel Patch panel Secondary access panel
LabView Dell Workstations Portable DAQ These systems (3 total) each consist of 16 channels of National Instruments 16 bit data acquisition input channels, 4 analog output channels, and LabView 7 Express data acquisition development system. The systems are portable and can be used in the NEES/SEESL environment as well as in the various teaching labs located throughout CSEE.
Analog Signal conditioners Temposonic conditioner 2310 conditioner 2100 conditioner The temposonic conditioner supplies the Excitation required for operation and Offers a zero adjust for the output Both the 2310 and the 2100 supply excitation Voltage and amplification to a transducer. The 2310 also offers filtering and an auto balance feature. The can be used for any strain gage base Instrument as well as potentiometers and String pots.
Pacific Data Acquisition Hardware ( Pacific ) Chassis Cards ( type and quantity ) Calibration of amplifiers Connections System Transducer connections Location and interfacing DAQ patch panel Lab patch panels location and channel count
Data Acquisition System Hardware FEATURES Mounting for 16 input/output modules providing up to 128 channels expandable to 4096 channels High-speed IEEE-488 interface for control and data Optional PCM telemetry and SCRAMNet data output Fast hardware-based alarms with digital outputs 2M Sample ring buffer for event capture Built-in fans and cable tray Model 6000 Mainframe The 6000 Mainframe has an IEEE-488 interface, digital data selector (DDS) and 16 input/output module slots. Additional input/output modules mount in 6001 Slave enclosures. All enclosures are for mounting in 19-inch, EIA-310C type cabinets. The 6000 Mainframe supports up to 31 Slave enclosures or up to 4096 channels of transducer signal conditioning or digital I/O. All enclosures have fans providing air circulation and an integral cable tray that routes the input and output cables from the front of the modules to exit the rear of the enclosure. The digital data selector (DDS) inserts digitized data acquired by Series 6000 input modules in the output data stream according to a user-defined scan table. It also adds a header containing a 32-bit synchronization word, sample counter and start and trigger flags. A 1 Million word FIFO provides data output buffering during periods when the interface or computer is unavailable to receive data. This assures a continuous stream of uninterrupted data to the computer or other data recording device. The mainframe includes a ring buffer that stores up to 2 million data samples. It may be triggered by an alarm or external TTL input to save specified amounts of pre and post-trigger data. Optional data outputs include PCM telemetry and SCRAMNet. SCRAMNet provides the lowest latency for control applications.
Pacific sample rate Note: The aggregate rate does not take into consideration the bandwidth of the card
Model 6032 4 Channel Transducer Amplifier-digitizer FEATURES Programmable excitation, remote sensing Programmable input configuration Shunt and voltage calibration Automatic zero and balance Gains 1 to 5,000 with 0.05% accuracy 0 to 20 ks/s ADC rate with 16-bit resolution Continuous 10 Volt analog outputs The 6032 input module has four channels of high performance signal-conditioning amplifier-digitizers for strain gages and bridge transducers. Each channel has programmable excitation with remote sensing, voltage calibration, local or remote shunt calibration, programmable gain instrumentation amplifier and four-pole low pass filter. The high level outputs are multiplexed and digitized to 16 bits then output to the 6000 data bus. In addition to the digitized output, each channel provides a continuous analog output The 6032 is used with quarter, half and full bridge transducers, potentiometers and low-level voltage signals in demanding applications such as load control. The EM option adds continuous excitation monitoring with out-of-limit alarms. The PF option adds a four-pole, 4 to 1,000 Hz programmable filter with 1 Hz resolution. Voltage substitution using an external voltage standard is provided for traceable gain calibration. Internal or external shunt calibration is provided for transducer calibration. Transducer balance, zero and gain calibration are automatic. Two programmable alarms with upper and lower limits are checked for each digitized output. The high-level analog outputs provide a means to independently monitor or record each channel.
Model 6013 8 Channel Instrumentation Amplifier-Digitizer FEATURES Voltage, thermocouple and DC-LVDT Optional thermocouple reference junction Gains 1 to 5,000 with 0.05% accuracy Automatic zero and gain calibration Four-pole, low-pass filter 10 ks/s with 16-bit ADC Programmable alarm levels Analog outputs The 6013 input module has eight channels, each with programmable gain instrumentation amplifier, low pass filter and sample and hold. The high level outputs are multiplexed and digitized to 16 bits then output to the 6000 data bus. A ninth reference temperature channel conditions the output of the temperature sensors in Model 6015 and 6084 thermocouple reference junctions. The 6013 provides regulated DC power for transducers with integral electronics. Each channel has a continuous, wideband analog output. The 6013 is used with low-level voltages, thermocouples and transducers like DC-LVDTs that have built-in electronics and a voltage output. The power supply may be configured for ±12 or ±15 Volts DC. Voltage substitution is provided for channel gain calibration utilizing an external voltage standard. A calibration attenuator enables the voltage standard to be used on its highest accuracy ranges and provides a postattenuator output for calibration and verification. Using Pacific s PI660 software zero and gain calibration and correction are automatic. The four-pole, low-pass filter uses an easily changed plug-in module to set bandwidth. Either the wideband or filtered output may be digitized and sent to the 6000 data bus. Two programmable alarms each with upper and lower limits are checked each time the outputs are digitized. The high-level analog outputs provide a means to independently monitor or record each channel.
FEATURES Model 6047 IRIG Time Code Reader IRIG A, B and G 1 Microsecond resolution 100 mv to 10 Volt peak-to-peak input Days, hours, minutes, seconds, milliseconds and microseconds Simultaneous BCD and binary outputs Time kept by disciplined clock if IRIG signal is lost The 6047 IRIG Time Code Reader provides precision time references for measurement data acquired by the 6000 data acquisition system. Time is acquired from time code signals, IRIG A, B or G, applied to the BNC input. Time data is captured by the 6000's sample clock and can be selectively output in the multiplexed data stream with measurement data at any available sample rate. It enables data processing or export software to determine the measurement time of each data point. The 6047 occupies one slot in a 6000 series mainframe or slave enclosure. The IRIG Time Code Reader derives a 1 MHz clock from the IRIG signal that is accumulated to provide current time with 1 microsecond resolution. Current time is loaded into binary and BCD output registers (days, minutes, seconds, milliseconds and microseconds) by the 6000's sample rate clock assuring that the time recorded matches data sampled by all series 6000 input and output cards. A stabilized oscillator is disciplined to the IRIG time source. If the time source is lost, the time reader continues to maintain and output time, however time accuracy will be limited by the stability of the local clock. Using the 6000 digital I/O cards provides a means of recording the time of event inputs or the time an event is output.
Note: the 6013 has a fixed filter of 10 Hz
Card Calibration
Instrumentation connections Generic instrument interface to 6032 card Patch panel wire layout (new lab) Lab interconnect layout (new lab)
Pacific Interfacing Half bridge Full bridge Quarter bridge Potentiometer / string pot
Instrument and connector layout
Location and interfacing DAQ system Portable DAQ Instrument cable Break out box Break out box plug box Extension cable
Patch Panel layout
Video equipment Video cameras HD Web web video Still cameras (SLR)
Web base video Live video and remote monitoring with standard TCP/IP networks Increased memory and performance High quality motion-jpeg images at up to 30 frames / second Support for Pan, Tilt, Zoom units Built-in Web Server HD video For video recording of experiments, lab is equipped with one HD (High Definition) camcorder and One SD (Standard Definition) camcorder and 12 PTZ cameras. HD camcorder is JVC DIGITAL HD CAMCORDER JY-HD10U that has following features: High Definition Recording Capability: o 720/30P (MPEG2) o 480/60P (MPEG2) High Definition Playback Capability: o 1080/60i o 720/60P o 480/60isn o 480/60i 4:3 Standard definition Recording/Playback 480/60i 4:3 Recording on Standard Mini DV Tape Lens for HD video image x10, F1.8 Optical image stabilizer system: with on/off switch 1/3-inch 1.18 Mega-pixel progressive scan CCD (Single chip) 16:9 still image capture, MPEG-4 clip capture with SD memory card Real time video streaming possible via USB interface to PC
Still Cameras 3.7.1.5. Images Still Lab is equipped with two Digital SLR cameras: Canon EOS 10D and 20D for still image photography of the experiments. Table 15: 10D and 20D Specifications EOS-20D EOS-10D Sensor Type 22.5 x 15.0mm CMOS w/ RGBG filter 22.7 x 15.1mm CMOS w/ RGBG filter Sensor Resolution (total) 8.8 mega pixels 6.5 mega pixels Sensor Resolution (effective) 8.25 mega pixels 6.3 mega pixels Lens Compatibility EF and EF-S EF only mage Processor DIGIC II DIGIC Connectivity USB 2.0 USB 1.1 Flash Metering E-TTL II E-TTL
Type and quantity of instruments. Inventory Location of point of measurement (layout drawing). Expected full scale range of measurement. Nomenclature of channels to be used, involving descriptors of location. Test protocol and Test nomenclature Required output file format ASCII DaDisp Information for user test requirements
Information for user test requirements Type and quantity of instruments. Inventory Location of point of measurement (layout drawing). Expected full scale range of measurement. Nomenclature of channels to be used, involving descriptors of location. Test protocol and Test nomenclature Required output file format ASCII DaDisp
Example test Zipper frame Macarena Schachter Ph.D. candidate
Zipper frame instrumentation layout drawings Strain gage placement Accelerometer and displacement Krypton LED
Test predictions
Predicted full scale readings Time history of acceleration at third floor. LA22yy, simulated, 120% PGA. Time history of displacement first story. LA22yy, simulated, 120% PGA. 600 1 400 0.5 A [IN/S^2] 200 0 0 5 10 15 20 25-200 D [in] 0 0 5 10 15 20 25-0.5-400 -1-600 -1.5 t [s] t [s] Time history of μstrains at midpoint of the right column. LA22yy, simulated, 120% PGA. Time history of moment of right column at midpoint. LA22yy, simulated, 120% PGA. 0.005 150 0.004 100 0.003 0.002 50 μstrains [] 0.001 M [kip-in] 0 0 5 10 15 20 25 0 0 5 10 15 20 25-50 -0.001-0.002-100 -0.003-150 t [s] t [s]
Pacific Wiring Chart # NAME TYPE Location DDAS patch NOTES 1 SG1BMQNB1 Beam 1st floor north bottom, location 1. 0: 0: 0 A-1 T2-A-0 2 SG1BMQNB2 Beam 1st floor north bottom, location 2. 0: 0: 1 A-2 T2-A-1 3 SG1BMQNB3 Beam 1st floor north bottom, location 3. 0: 0: 2 A-3 T2-A-2 4 SG1BMQNB4 Beam 1st floor north bottom, location 4. 0: 0: 3 A-4 T2-A-3 5 SG1BMQNT1 Beam 1st floor north top, location 1. 0: 1: 0 A-5 T2-A-4 6 SG1BMQNT2 Beam 1st floor north top, location 2. 0: 1: 1 A-6 T2-A-5 7 SG1BMQNT3 Beam 1st floor north top, location 3. 0: 1: 2 A-7 T2-A-6 8 SG1BMQNT4 Beam 1st floor north top, location 4. 0: 1: 3 A-8 T2-A-7 9 SG1BMQSB1 Beam 1st floor south bottom, location 1. 0: 2: 0 A-9 T2-A-8 10 SG1BMQSB2 Beam 1st floor south bottom, location 2. 0: 2: 1 A-10 T2-A-9 11 SG1BMQSB3 Beam 1st floor south bottom, location 3. 0: 2: 2 A-11 T2-A-10 12 SG1BMQSB4 Beam 1st floor south bottom, location 4. 0: 2: 3 A-12 T2-A-11 13 SG1BMQST1 Beam 1st floor south top, location 1. 0: 3: 0 B-1 T2-A-12 12 14 SG1BMQST2 Beam 1st floor south top, location 2. 0: 3: 1 B-2 T2-A-13 15 SG1BMQST3 Beam 1st floor south top, location 3. 0: 3: 2 B-3 T2-A-14 16 SG1BMQST4 Beam 1st floor south top, location 4. 0: 3: 3 B-4 T2-A-15 17 SG1BMVB1 Beam 1st floor, shear rosette, bottom location1. 0: 4: 0 B-5 T2-B-0
Web Information resource http://nees.buffalo.edu http://nees.buffalo.edu/docs/labmanual/seesllabmanual.pdf
Hybrid Experiment
Thank You! Questions?