During a conversation with Dr. Ralf Cramer, who heads up the Chassis & Safety Div. of Continental AG (conti-online.com)—which is responsible for developing and producing electronic and hydraulic brake and chassis control systems, sensors, driver assistance systems, airbag electronics and sensors, washer systems, and electronic air suspension systems—he emphasized the importance of moving from passive safety systems to active systems.
And he pointed out that a key building block for active safety is electronic stability control (ESC), which is now mandatory on new vehicles sold in the U.S., and which will be required in Europe and Japan in 2014 (although not for the tiny Japan-market K cars).
While Cramer explained that in addition to functions like automatic cruise control, which combines radar systems with a vehicle’s braking system in order to maintain a set distance between one’s vehicle and that ahead, and automatically braking should that become necessary, he thinks that there is a greater need for urban traffic- pedestrian-focused systems, such as the “Pedestrian Protection with Full Auto Brake” system available from Volvo, as well as the Volvo City Safety system that is engineered to avoid or mitigate accidents at speeds under 19 mph.*
One aspect that has to be taken into account with systems that can provide quick stops is the ability of the brakes to have sufficient pressure when drivers jump on the binders. This can be an issue when there are electric vehicles or even diesel vehicles in the picture, due to the absence of or limited amount of vacuum that can achieve the sort of hydraulic pressure in a braking system needed to get this fast stopping done.
One recent development from Continental to address this is the MK C1, which combines brake actuation, the brake booster, and the control systems in a single electro-hydraulic unit. It is capable of building braking pressure faster than conventional hydraulic systems. That’s because it uses an electric motor that drives a cylinder piston in a linear way, which is particularly useful during emergency braking situations. It doesn’t require a vacuum brake booster.
Another benefit of this system is that it uses the energy required to get the job done. That is, say there is a regular driving situation wherein the driver wants to slow the vehicle down and only 5% of the braking force is needed. The MK C1 delivers only that pressure and no more, unlike conventional systems based on hydraulic accumulators.
Also, the elimination of the vacuum pump and the multi-piston hydraulic ESC pump means that the system is much quieter, which is certainly important, particularly in hybrid and electric vehicles, where there is little (if any) engine noise to mask the sound of these pumps.—GSV
*It seems that pedestrian safety is getting all the more dicey, based on pedestrians wearing headphones. According to research revealed in mid-January conducted by the University of Maryland School of Medicine and the University of Maryland Medical Center in Baltimore, in 116 accident cases from 2004 to 2011 in which the injured pedestrians were documented to be wearing headphones, 70% resulted in death by either train or motor vehicle, despite the fact that 29% of the vehicles reported to sounding some sort of warning. According to Richard Lichenstein, M.D., lead author of “Headphone use and pedestrian injury and death in the United States: 2004-2011,” “Everyone is aware of the risk of cell phones and texting in automobiles, but I see more and more teens distracted with the latest devices and headphones in their ears.” As Lichenstein is director of pediatric emergency medicine at the University of Maryland Medical Center, he may be seeing these headphone-wearing pedestrians in some unfortunate circumstances.