building a rugged and flexible in-vehicle testing solution to measure the vibration levels.
A large-engine manufacturer had test cells with severe vibration levels…
Automotive and off-highway engineers and designers often need to log vehicle bus data along with vibration, strain gauge, and other sensor data during normal operation to evaluate their design. Using data from all these sources enables these engineers and designers to pinpoint a vehicle’s response to staged or damaging events. For example, engineers can see how steering wheel position and speed effect structural response when the vehicle hits a pothole.
How does steering wheel position and speed effect structural response when the vehicle hits a pothole?
In situations where our engineers need to tap into the vehicle’s on-board diagnostics using CAN bus data and analog sensor data to identify and solve a problem, we will deploy a rugged measurement solution based on NI CompactDAQ (cDAQ) hardware. These systems usually include an industrial compact pc or standalone cDAQ running the iTestSystem engineering measurement application. iTestSystem logs data from the vehicle bus connected to NI 9862 CAN module and other analog sensors connected to NI cDAQ modules like NI 9234, NI 9236, and NI 9229 into one data file.
NI 9862 CAN Module Specifications and Connections
According to the NI data sheet, the NI 9862 modules is a single CAN port device that is isolated from the other modules in the system. The port has a Bosch DCAN CAN controller that is CAN 2.0B-compatible and fully supports both 11-bit and 29-bit identifiers. The port also has an NXP TJA1041AT High-Speed CAN transceiver that is fully compatible with the ISO 11898 standard and supports baud rates up to 1 Mbps. This module requires +9 to +30 VDC supply voltage to operate.
The table below shows the connections between the NI 9862 9 pin D-Sub and the SAE J1962 connector that are required for CAN communication. NI sells a OBDII9M-DB9F CAN Cable cable if you don’t want make your own cable.
iTestSystem CAN Channel Setup
Setting up a vehicle CAN bus connection can be difficult, especially if you need to acquire non-standard, proprietary messages and frames. iTestSystem simplifies this setup by leveraging the NI XNET and CAN drivers to view and configure CAN bus data, import databases, and assign scale factors. iTestSystem then allows users to browse and choose which CAN signals to acquire.
For more information about collecting CAN bus data with an NI 9862 and iTestSystem, or our testing services, contact Chase Petzinger via email at firstname.lastname@example.org or phone at (844) 837-8797 x704
- Sound & Vibration DAQ Tools: NI-9231 Module
- Engineering Data Acquisition Tools: NI-9236 Strain Module
- How Do I Collect Vibration Data with iTestSystem and a cDAQ?
Suspended in a harness 30 feet above a concrete spillway in central North Dakota, ITM engineer Ryan “RJ” Matthews instruments the gate of one of the world’s largest earthen dams with dozens of strain gauge sensors.
Integrated Test & Measurement’s field service technicians and engineers have installed strain gauges on civil structures and machinery around the globe for decades, and this project represents one more example of rugged data acquisition. In this instance, the team rappelled from an overhead abutment on the Garrison Dam — a 2-mile-long structure along the Missouri River built by the Army Corp. of Engineers starting in 1947.
Contracted by Cotech IRM Services, ITM was charged with collecting data to measure the strain on one of the 28 spillway gates which are designed to raise and close to allow water to pass from the reservoir during rare flood events. Just behind those gates is Lake Sakakawea, one of the largest man-made lakes in the United States.
Despite the complex location, Matthews and co-worker Zach Strong were able to successfully instrument the spillway gate with 44 single-axis strain gauges and solder signal cables which lead back to a NI CompactDAQ system connected to their laptop, allowing them to successfully gather streams of crucial data using iTestSystem while the gate was put through its paces.
The project is yet another example of ITM’s ability to combine the use of strain gauge sensors, a cDAQ system and the firm’s iTestSystem software to create a structural health monitoring system. In this instance, the project required only one-time testing, but ITM can also establish a permanent structural health monitoring system as well. iTestSystem is an engineering measurement software platform that enables test engineers to organize, acquire, view, and analyze data from machinery, processes, vehicles and other complex systems. iTestSystem was specifically designed for use with National Instruments (NI) cDAQ hardware for data collection and data logging.
For Matthews, it was his first experience installing strain gauges while strapped into a bosun’s chair and dangling in midair, but he points out that ITM’s strain gauge process is essentially the same whether their engineers are standing on a bridge or inside a railcar. All that changes is the method of access and environment.
His field notes reveal that each strain gauge on this job was wired in a quarter bridge configuration, which provides one individual measurement of strain (positive tension or negative compression) per location. All gauges were adhered to the gate using M-bond 200 epoxy. A final report submitted to the customer contained detailed instrumentation and test notes and results reported in a series of stress/strain tables and stress graphs.
Contact ITM for your Strain Gauge Needs
Installing strain gauges in the field for structural and fatigue measurements requires expertise and experience. Whether you use our iTestSystem software to stream and analyze strain signals for static measurements and real-world fatigue data acquisition or contract our software engineers to build a real time strain monitoring system, we will make sure you acquire quality strain data. Contact our strain lab and technicians to install strain gauges on test specimens or to design, build, calibrate, and test strain-based load cells.
Strain Lab Contact Info: Ryan.Welker@iTestSystem.com, (844) 837-8797
Faced with the challenge of testing a large and complex on‐highway vehicle, engineers from Integrated Test & Measurement knew it would take hundreds of channels…
When measuring noise and vibration levels, our engineers use the NI-9231 sound and vibration module, a CompactDAQ chassis and a Laptop running iTestSystem for data logging and analysis. The NI-9231 module is an updated, higher channel count version of the NI-9234 module.
The NI-9231 is an 8 channel, 51.2 kS/s/channel, -5 V to 5 V, C Series Input Module with IEPE excitation that can be turned on and off, and open/short circuit detection. To increase channel capacity, these modules use 10-32 plug for its sensor input connections. NI provides a PCB Low Noise Coaxial Cable, 10 ft w/10-32 plug to BNC plug to accommodate most standard accelerometer and microphone connections.
For more information about doing data collection with the NI-9231, iTestSystem or sound and vibration measurements, contact Ryan Welker via email: email@example.com or phone: (844) 837-8797 x702
Obvious signs of fatigue — cracks at the corners of doors — had begun to surface on an in-service Railcar. A railcar structural testing case study.
The most common strain gauge installation configuration is a 350 ohm, quarter bridge. Quarter bridge installations a generally the easiest and most economical installation for determining structural strain levels. In the quarter bridge configuration a single element strain gauge is mounted in the principle axial or bending strain direction.
One tool that our engineers and technicians use to collect data from 350 ohm, quarter bridge strain gauge installations is the NI-9236 strain module. The NI-9236 is an 8-Channel C Series 350 ohm strain/bridge input module that is used with a CompactDAQ or CompactRIO chassis. This module provides bridge excitation (3.3 Volts), Wheatstone bridge completion, shunt calibration, and filtering for 350 ohm quarter bridges. Use this module in conjunction with a CompactDAQ chassis and iTestSystem engineering measurement software to collect synchronized, high-speed (10kHz) structure strain data.
For more information about the NI-9236, DAQ module rental, strain gauge installations or our data logging solution iTestSystem, contact Ryan Welker via email: firstname.lastname@example.org or phone: (844) 837-8797 x702
We are excited to announce that the NI-9205 general purpose analog input module can now be used with iTestSystem and NI CompactDAQ. Adding this module allows engineers to expand the use of iTestSystem from structural testing and analysis where signal phase relationship is important, into data logging where phase isn’t as high a priority. The NI-9205 features 32 single-ended or 16 differential analog inputs, 16-bit resolution, and a maximum sampling rate of 250 kS/s.
Our customers really wanted this module added and I can see why. If the NI-9205 module is combined with iTestSystem’s free feature set, they could build a flexible and cost effective data logger. With the extended feature set of iTestSystem, they could also build a standalone logger, with triggering and CAN support.
For more information, visit https://www.itestsystem.com
During NI Week every year, Austin, Texas, transforms into a mecca for top engineers and scientists worldwide who come by the thousands to absorb the very latest in tech.
This year ITM will once again be attending, but even more exciting is that our team will once again be presenting at the National Instruments sponsored conference.
Ryan Welker, ITM’s Lead Test Engineer, will be co-presenting with NI on “Best Practices for Powering, Mounting, and Enclosing Your CompactDAQ(cDAQ) System” during hour-long sessions on Wednesday, Aug. 5 at 10:30 a.m. (Room 12B), then again on Thursday, Aug. 6 at 10:30 a.m. (Room 13A/B).
Ryan will be sharing details about the cDAQ hardware packaging that ITM uses to gather data in even the harshest environments as well as the proprietary iTestSystem software solution (now available as a free download) that ITM has developed to pair with NI’s equipment.
If you are at NI Week, hope you can check out the presentation or feel free to connect with us online.
— ITM President Tim Carlier
ITM | Integrated Test + Measurement
227 Water Street, Suite 300
Milford, OH 45150
Email: ITM Sales
ITM provides software development, structural and mechanical testing services, industrial monitoring, strain gauging, and data analysis solutions to clients on six continents. ITM is a recognized National Instruments Gold Alliance Partner.