Poling Group News   |   Volume 4  |   Issue 1

Smarter, Faster Tire Data Acquisition

Do your tire testing machines take advantage of technology designed specifically for tire data acquisition?
Test machines that still use signal conditioning devices designed to service general data acquisition requirements miss out on the benefits provided by TDAQ—Poling Group’s innovative product specifically targeted to meet the demanding needs of tire data collection.

It's All About Speed

While modern PLCs used by some test machines peak at about 1,000 I/O per second, TDAQ runs at a lightning-fast 16,000. But its real power comes from the ability to make split-second decisions without relying on outside commands from an external machine controller.

What real difference can TDAQ’s blazing speed make with regard to testing tires? Consider the beadseat process, where a tire inflates to 30 PSI (2 bar) above test pressure for about one second, after which air is quickly released to achieve setpoint. During the deflation step, TDAQ monitors the falling pressure at 16,000 times per second. At exactly the right moment, it instantaneously turns on the output to close the air exhaust valve, immediately settling the tire’s internal pressure at the desired setpoint.

Compare TDAQ’s reaction to that of a modern PLC. First, the PLC must wait for the most recent air pressure value to be streamed in from an analog input card. Then, a random amount of time elapses before the PLC executes the right rung in its program to perform the air pressure check. And, if the output that controls the exhaust valve happens to be in another remote I/O rack—connected over Ethernet and shared with another dozen devices, that variance in latency all adds up.

Not only does TDAQ save machine cycle time by eliminating all of the PLC latency involved, but now tire test results are more accurate. Removing random variation from beadseating and other time-critical processes allows each tire to test more consistently, increasing machine repeatability.

The Right Design

Poling Group considered many off-the-shelf DAQ products to improve performance of its state-of-the-art tire testing machines. But the complexity inherent in each product designed for general use kept us from meeting our goals. So we decided to provide our own, smarter solution for load cell data acquisition, and TDAQ-LC was the result.

The TDAQ-LC’s powerful circuitry produces excitation for each load cell with an ultra-low-noise voltage reference circuit, then amplifies the returning signal 125x before feeding it directly to an analog-to-digital converter. The compact package is RF-shielded and designed to mount directly on the loadwheel carriage. This close proximity to the physical sensors eliminates the need for long cables that are prone to signal noise and distortions.

This combination of shielding, shorter cables, and dedicated analog processing greatly increases the precision of tire test data. So we took advantage of the enhanced resolution by developing Machine Effect Characterization and Compensation (MECC), a new class of software that allows us to perform tooling compensation on specific parts of the machine, such as the loadwheel, to minute detail.

On a very large loadwheel designed to test truck tires with 4500 pounds (2000 daN) of force, a loadwheel runout of even .0004 in (10µm) can add unwanted variation to tire test results. With TDAQ-LC, not only do we detect and compensate for this runout, we’ve also been able to detect the flex and bend of the wheel's aluminum surface as the tire rolls between its reinforced spokes.

With the TDAQ's built-in quadrature decoder we can match up the tooling compensation of the loadwheel directly to the incoming stream of load cell data, canceling out almost all of the changes in the tire waveform caused by the loadwheel. Now tires are tested more accurately with the TDAQ than was ever before possible.

TDAQ Product Family

In 2008, we originally designed TDAQ to do one thing and one thing well: tire testing.

Since that time we’ve expanded TDAQ into a product family that includes the TDAQ-XT (Crosstalk Compensator) and the TDAQ-SSI (Synchronous Serial Interface), which provide specific solutions for customer-identified input or control requirements not already supported by TDAQ and TDAQ-LC.

Designed for Scalability

  • For the majority of tire testing machines, pair a TDAQ-LC with a single TDAQ to deliver tire test data over Ethernet to the TTOC PC.
  • For larger machines equipped with many devices such as grinders or geometry sensors, connect up to eight TDAQs. Real-time synchronization ensures that data packets from various parts of the machine arrive simultaneously at the TTOC PC, which combines them to form a single, complete image of the machine state at a rate of 16,000 times per second.
  • For simple tire/wheel machines where there is no air pressure measurement involved, install a single TDAQ-LC to measure tire force data.

Benefits for Retrofits

  • For machines without a servo or PLC driving the spindle, TDAQ can automatically turn on an output to stop the spindle at a specific position for marking, or even spray an ink mark at just the right location on a spinning tire.
  • One TDAQ can also digitize an entire set of analog machine controls, giving machine operators pin-point precision over a once ambiguous interface.

Never in the history of tire testing has there been a more effective way to collect and analyze tire data!

Visit us at https://www.polinggroup.com/solutions_tdaq.php to learn more about how TDAQ can revolutionize your tire test machine.

The TDAQ Product Family
(Synchronous Serial Interface)

Crosstalk Compensator)
16,000 I/O scans per second
10/100 Mbit Ethernet
Spindle quadrature decoder
High-speed load wheel rotation counter
24-bit Analog Inputs
10-bit Analog Inputs
16-bit Analog Outputs
Digitial Inputs
Digitial Outputs
16,000 I/O scans per second
10/100 Mbit Ethernet
Spindle quadrature decoder
24-bit Strain-gage Analog Inputs
Digital Inputs
Digital Outputs
Small 4" x 6" (10cm x 15cm) package mounts directly on the machine next to the load cells
Custom solutions for 21st-century tire factory data acquisition problems.
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