Sensors take control to avoid collisions
By Paul Abelson
Each year, the Bureau of Labor Statistics publishes data on fatalities and work-related accidents by occupation. Each year, truck driving ranks between 4th and 10th. Crash rates have gone down each year, especially when measured in terms of rates per 100 million truck miles traveled but the dangers still exist.
Rollovers lead the list in causing truck driver deaths. Injuries and fatalities to occupants of other vehicles happen most often when trucks rear-end cars. Other crash causes include sideswipes from lane departures, loss of control when tires blow out and, finally, poor visibility due to weather.
Almost every association and company in the industry is working to cut those dangers down. Driver training is getting better. The role that highway and road conditions play in crashes is recognized, and the industry is working to improve them. More drivers are using seat belts, and air bags are appearing on more new trucks.
But one the biggest safeguards against collision comes courtesy of today’s advanced sensor systems. Modern electronic technology has given us devices that can help mitigate or eliminate crashes.
The systems that can help
Almost every crash-risk scenario now has a device to prevent it or soon will.
Automatic inflation systems from Meritor PSI and Roadranger keep trailer tires up, and air pressure monitoring from TireStamp, SAF-TTE, Pressure Pro and Doran alert drivers when pressures drop in tractor or trailer tires. That means that tire blowouts due to under-inflation will soon be ancient history.
A technology from Iteris uses optical recognition to determine where a vehicle is within its lane. If the truck makes an unintended deviation without signaling, the device determines when to alert the driver with a rumble strip sound and sensation. Mobileye couples lane departure warning with frontal distance warning that uses both a sounding alarm and a visual indication that a collision is imminent. These wake-up calls to distracted or drowsy drivers are effective regardless of weather conditions.
Experimentally, the type of recognition technology used in these systems has been used with electric power steering to let a computer steer a car. This is something that will be done on an exceptions-only basis if and when it ever comes to pass. On the other hand, having a computer engage the brakes when necessary is now a reality. Arvin Meritor recently demonstrated OnGuard, an adaptive cruise control system that uses forward looking radar to activate service brakes if a warning of potential collision goes unheeded, as when a driver is distracted or possibly dozes off. First, a warning light flashes. Then a signal sounds. If those are ignored, the system takes over to mitigate the severity of the crash or even eliminate it completely. If the driver takes control by steering away or braking, that overrides the system.
In a similar vein, Bendix has been developing rollover mitigation in conjunction with their traction control and stability systems for tractors. Bendix ABS 6 Advanced with ESP is standard equipment on Mack trucks. Rollovers can often start at the trailer, and are uncontrollable by the time they can be detected by the driver. Meritor WABCO and Haldex have rollover control systems that work in and on trailers. The trailer systems can be retrofitted.
Safer trucking through technology
Now let’s do some creative thinking and start putting these systems together. Thanks to the progress in computers, machines can determine velocity and direction, identify shapes and sizes of moving and stationary objects and measure inputs such as steering direction and brake or throttle applications. They can distinguish between a gradual stop and a panic stop, or a gradual acceleration and amaximum power application. You can already buy Eaton VORAD’s adaptive cruise control that de-fuels the engine and applies a Jake Brake or retarder. Why shouldn’t it be able to apply service brakes? You can already buy skid control and rollover mitigation.
So here’s how it all comes together. Radar on the upper corners or roof of the tractor continually surveys the landscape (or cityscape) in an arc around the truck. The computer detects and evaluates potential threats on a continuous basis. It never gets distracted. It never sleeps, except when the truck is asleep. If the computer detects the potential for a crash, it alerts the driver with anything from lights to audio alarms to vibrating seats that sound and feel like a rumble strip. If the driver doesn’t react quickly enough, or reacts improperly, the truck will be able to slow down, speed up, stop or even steer out of harm’s way. Crashes that might have happened don’t. Crashes that do happen, wind up being much less severe than they might have been.
The net result will be positive for everyone. We’ll have fewer crashes, less severe crashes, fewer and less severe injuries and, of course, fewer and lower repair bills. And maybe, just maybe, trucking will break out of that “top 10” in the accident statistics.
Believe it or not, we’re halfway there already!
Who’s in Control Here? Don’t worry, it’s still the driver
Do all these devices mean that the role of the driver will be minimized, opening the door for inexperienced “newbies” to sit in the left seat and just point the truck? I doubt it. In fact, if modern aircraft are any indication, the new technologies will raise the skill levels of all drivers and make experienced personnel more important than ever. Whether civilian or military, electronics have made airplanes more capable and safer. Functions that were done manually now must be done by computer as planes get more complex and operate in increasingly congested skies.
Pilots who are better trained and more highly skilled are in greater demand because they manage systems in addition to pointing their craft where it needs to go. That will become the role of truckers as systems develop. Drivers will be monitoring and managing systems as well as steering operating the truck.
How far we’ve come
One of the major advances for truck safety came back in the 1970s, with the earliest anti-lock braking systems (ABS). ABS does not help you stop more quickly. Instead, it prevents loss of control which happens when a wheel locks-up and slides. ABS senses each wheel’s speed and compares it to other wheels. When one wheel slows more rapidly than all the others, indicating the start of a lock-up, the system releases pressure to that wheel’s brake. When wheel speed is where it should be, normal braking resumes on that wheel.
The same concept, the independent release if braking pressure to one or more wheels, can be used to independently apply brakes, not just release them.
By the late ’80s, computers were more than 156 times more powerful than those available for the first ABS. Field tests proved ABS performance long before the NHTSA (National Highway Transportation Safety Agency) once again required them, for tractors in 1997 and trailers in 1998.
Today’s systems are roughly 32 times more capable than when ABS was finally required in the ’90s and was seamlessly integrated into trucking operations. Even more importantly, electronic devices have become miniaturized. Sensors and accelerometers, now smaller than a fingernail, are far more sensitive and responsive than ever before. They can detect rates of changes in motion, process the information and determine the best corrective action when abnormalities occur, all in far less time than a human can even detect that problems are starting.