Instead of relying on data collected in third-party wind tunnels designed for the aerospace and automotive industries, not for cyclists, Specialized Bicycle Components (Specialized) became the world’s first bike and equipment manufacturer to build a sport-specific wind tunnel located at its Morgan Hill, California facility.
Specialized aerodynamics R&D engineer Chris Yu says they chose to work with National Instruments to build the sport-specific wind tunnel because of several factors, including “NI’s ability to integrate a variety of I/O and modern instrumentation, the flexibility to adjust small variables and easily change the tests, and the speed at which this unique system could be developed to address our specific measurement needs”.
“Being able to access custom testing 24/7 will lead to innovations for the cycling industry that may have not surfaced otherwise,” he says.
One of the biggest challenges cyclists face is drag caused by wind. To minimise drag by creating better cycling products and understanding how riders can better position themselves on their bikes, Specialized needed an accurate way to measure and test the effects of drag on cyclists as they ride in a real-world environment.
In a sport in which seconds often separate winning from losing, it is critical to understand and optimise each factor that affects a cyclist’s body and bike while riding.
Drag caused by wind presents one of the biggest challenges for cyclists. As they pick up speed while riding, their bodies, bikes, and equipment force a separation of air, resulting in a resistance called pressure drag. Since drag increases with speed, riders feel more resistance at higher speeds and must use more power to overcome the forces working against them.
Cyclists use between 70 and 90 percent of the power they generate to overcome aerodynamic drag. Thus, minimising drag through effective body positioning and aerodynamically refined equipment helps cyclists achieve maximum efficiency and speed.
Wind tunnel testing is crucial for bike manufacturers to optimize their equipment. Previously, the only wind tunnel options were third-party facilities not specifically designed for cycling tests. These facilities were time consuming and inconvenient for bike manufacturers to use. Therefore, Specialized built a wind tunnel to bring all aspects of the aerodynamics testing process to its Morgan Hill, California, facility.
Specialized now conducts a continuous loop of development and testing for all of its bikes and equipment and supports its team of professional cyclists by evaluating and optimising their riding positions. The bike and rider are almost never steady in real-world conditions and constantly interact with each other. Testing bikes in this realistic, dynamic way, as opposed to the traditional tests with the bike rigidly bolted to the tunnel, will uncover new information that would not have surfaced otherwise.
Specialized used NI LabVIEW system design software, NI PXI hardware, NI Vision Development Module software, and commercial off-the-shelf (COTS) components to develop a custom measurement and control system. With LabVIEW, Specialized can interface with the sensors placed on a bike and cyclist in the wind tunnel while engineers monitor data remotely on an iPad using the Data Dashboard for LabVIEW mobile app. Additionally, the COTS cameras capture real-time visual data, which easily integrates into the system using the Vision Development Module.
The flexibility of the NI PXI chassis helps Specialized create additional tests using new sensors and controllers with relatively quick turnaround times. This is especially important since test needs change regularly – for example, performing R&D testing on equipment versus performance testing with professional athletes. With the NI PXI chassis, users can swap in the right hardware effortlessly.
Specialized developed the entire measurement and control system in just a few months while seamlessly integrating each element of the system, which optimised time to market and is the biggest advantage of the system design approach. LabVIEW provided a single software framework to meet the unique requirements of performing control, measurement, and vision acquisition. The consolidation to a single software solution, tightly integrated with reconfigurable hardware, also simplifies the maintenance and supportability of the system.
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