The development of Antilock Braking Systems, or ABS as it’s more commonly referred to, really marks the beginning of the driver assistance system revolution. Why? Because for the previous hundred years or so of heavy truck brakes, braking was a mechanical, not electronic, function. To engage the brakes, the driver stepped on a pedal and some lever, wire, fluid or air moved to engage the brakes. Mechanical, not electronic. With ABS two things happened to the braking system – it could think and it could see.
The thinking part of ABS comes from its brain – the ECU – electronic control unit. The ECU contains the algorithms that, based on input from the eyes (in this case the wheel speed sensors) determines if a course of action is needed to mitigate a skid situation. If the ECU determines that an intervention is necessary, the system engages the modulators to release the brakes and “cycle” them, to help the driver control a skid. Brains and eyes – thinking and vision via the ECU and sensors, revolutionized braking on heavy vehicles. More importantly, ABS provided the foundation for advancing technologies to help drivers in more situations to control their trucks and avoid crashes or have the opportunity to reduce the intensity of crash situations. NHTSA (National Highway Traffic Safety Administration) saw the value of the technology to help keep control of their vehicles and mandated ABS for tractors in ’97 and for single unit trucks and trailer in ’98. This not only made the technology widely available, it also made it cheaper as economies of scale of a mandated product, as opposed to optional, kicked in and reduced the costs for the technology.
Add a few additional sensors to the braking system, beef up the ECU with some additional algorithms and now you have electronic stability control (ESC). Electronic stability control (ESC), or what we introduced to the market in 2004 as Bendix ESP helps drivers mitigate not only rollovers, but loss-of-control situations on dry, wet, snow- and ice-covered roadways . The three sensors that get added? First, a steer-angle sensor which provides information about the driver’s intent on where he or she wants the vehicle to go. Second, a yaw-rate sensor which provides information to the ECU about which direction the vehicle is going. Finally, a lateral acceleration sensor which delivers input about side forces acting on the vehicle. These three sensors provide input into the ECU which then compares these readings with algorithms to determine if a stability event – rollover and/or loss-of-control is going to occur. If the system determines this is happening, the system intervenes by reducing speed either through throttle reduction or, if necessary, applying the brakes on the steer, drive and trailer axles to help the driver mitigate the situation. Now, drivers have an aid to help them avoid one of the most dangerous and deadly crashes in the trucking industry. This is another technology that NHTSA has mandated for Class 7 & 8 tractors and motorcoaches beginning in 2017.
Moving forward to 2009, an additional sensor – a radar – is added to the front of the vehicle. The radar provides information about what’s happening in front of the vehicle, sending out a signal to detect metallic objects in the vehicle’s path. This additional sensor, along with the stability system built on ABS, provided adaptive cruise control (ACC) for commercial vehicles. With ACC, when the driver engages the cruise control and sets speed, the system helps him or her maintain a set following distance behind a forward vehicle. As the gap between the truck and forward vehicle starts to close, the system provides the driver following distance alerts. If necessary, the system will dethrottle, engage the engine retarder and apply the brakes to help the truck maintain the following distance. While the intervention for adaptive cruise control with braking only occurs when the vehicle is in cruise control, the driver still receives following distance alerts whether in cruise control or not, to keep him or her aware of the distance between the truck and the forward vehicle.
Adaptive cruise control, or what we call, Bendix Wingman ACB – Active Cruise with Braking, starts the integration of technologies for advanced driver assistance systems. Wingman ACB brought together both a collision warning & mitigation technology with full stability to help drivers in a variety of situations, from rollovers and jackknifes to rear-end collisions. All in one package. All designed to complement, not replace, safe drivers and safe driving practices.
In 2011, the next step in advanced driver assistance was delivered – Wingman Advance, a collision mitigation technology. Upgrading the software in the radar, and eventually upgrading the radar hardware, added to the adaptive cruise control of Wingman ACB autonomous emergency braking (AEB). Whether the driver was in cruise control or not, when the system determines a collision is imminent, it alerts the driver and applies the brakes to help the driver mitigate the collision situation. Also built on stability, Bendix Wingman Advanced does more to help drivers improve safety performance on the road through alerts and mitigation regarding rear-end collisions, rollover and jackknife situations. Bendix was also first to include a stationary object alerts, which provide the driver an up to 3 seconds head’s up of a metallic object of size in his or her lane of travel. This alert provides the opportunity for the driver to slow, or, if necessary, swerve to avoid the object.
The value of the technology can be summed by a major fleet customer which saw a reduction of up to 70% in the number of the rear-end crashes and up to a 70% reduction in the severity of the remaining 30%.
From ABS with an ECU and wheel speed sensors to full stability control with additional algorithms and sensors to adaptive cruise control and collision mitigation by adding additional logic and sensors – all in the last 20 years. Imagine what the next 20 years will bring! Now that we know where we are…where do we go from here?
Autonomy – in a nutshell is what the future holds. The path leads towards increasing autonomous applications to further assist drivers in a variety of situations on the roadway. First step for Bendix along this path has been to add a camera to the radar and create the recently introduced Bendix Wingman Fusion system – a system that takes input from both the camera and the radar to deliver a higher level of collision mitigation. Think about it, when you make a decision, isn’t it better to have more than one source of information? That’s what’s happens with Fusion – the camera and the radar work together, enabling the system to cross-check information for an earlier read of the situation and deliver an appropriate intervention earlier, than the previous radar-only based system. Also, as important is being able to reduce false alerts and, probably more importantly, false interventions. While false alerts can be a driver dissatisfier, false alerts can be dangerous – as when the truck brakes for a non-threatening obstacle or overhead signing and resulting in a crash from a car following too close behind.
Considering the pathway to driverless vehicles, additional sensors (more information into the system) along with advanced algorithms (the intelligence of the system) will help drive more and more autonomous applications that, over the next 10 years will continue to help drivers do their jobs more effectively and efficiently. Driver assistance systems today are controlling acceleration and braking, as we look to the future, adding steering control will likely be the next step. Steering control will assist in such autonomous application such as lane keeping (helping the driver stay in the center of the lane), self-parking, loading-dock assist and even providing automated driving on long stretches of roadway. Again, applications designed to help drivers, but not replace drivers.
Beyond this, expectations for driverless vehicles are high, as already driverless truck retrofits are being touted and innovative approaches are being demonstrated. However, getting to truly driverless vehicles will take some time. While technology has advanced greatly and will continue at a fast pace, societal acceptance and government regulations will not move at the same speed. Incidents involving driverless functions and concerns about cybersecurity around driverless vehicles will ensure that time is taken to develop robust and secure systems. The need for virtually flawless driverless system performance cope with the myriad of situations that human drivers face today, in all weather conditions and along all types of roadways will require time, testing and tweaking. Also critical will be the security infrastructure both on and around the vehicle. It’s critical that a driverless vehicle’s control systems cannot be hacked by outsiders for kicks or nefarious activities. Performance expectations and specifications will be required to ensure systems perform properly and simply, so drivers (Or are they now passengers?) can enjoy the benefits of the system without worrying about the need to take over immediately because the system can’t handle a particular situation. Driverless will come, but not for a good while yet!
Increasing safety and performance on the road, now and into the future. To think it all started with brakes, brains and vision.
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