Wear and tear on Humvees need not slow down the U.S. Army – soldiers could soon drive over speed bump-like diagnostic cleats to determine the conditions their vehicles are in.
Embedded sensors could detect suspension or tire problems by comparing vibration signatures with the baseline signature of a healthy vehicle. Researchers used triaxial accelerometers to gauge tire forces in a cleat prototype.
"The cleat is a quick first check to determine what's mechanically wrong with a vehicle before wasting time hunting for potentially simple problems," said Joseph Gothamy, who leads the reliability and durability simulation team at Army's Tank Automotive Research, Development and Engineering Center, in Warren, Michigan.
The sensor speed bump costs roughly $1,500 and could stave off the more expensive option of rigging all current vehicles with sensors. It also provides an alternative to the current maintenance schedules that are based on reliability estimates for Humvees. Such estimates may not hold up when Humvees are subjected to different tasks and environments, so the sensor speed bump would potentially lead to more accurate and tailored vehicle maintenance procedures..
"Some vehicles may be used at checkpoints while others may be hauling supplies hundreds of miles," Gothamy said. "Even if the same vehicle variant is used, they are on very different missions, and trying to use the same regular maintenance schedule for both isn't always efficient or effective."
Researchers at Purdue University tested the system using Humvees and computer simulations. They found that the sensors could pick up on simulated coil spring damage in the Humvee's front suspension, even at different tire pressures.
According to Douglas Adams, a mechanical engineer at Purdue University, the system could eventually alert maintenance personnel to everything from deflated tires to shock absorber problems.
"Let's say one of the tires is severely under pressure," Adams said. "The cleat tells you to turn around and fill up that tire because you are about to embark on a 10-hour mission with this vehicle."
For now, the main challenge lies in acquiring enough data to build up a library of vibration signatures that can troubleshoot various problems under different conditions. The U.S. Army plans to do further testing at various Army depots, and will conduct a large survey of vehicles returning from overseas deployment – because even Army tough can use a checkup every now and then.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.