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31/08/2015
TORRICELLI VACUUM BRAKE!

Safety Devices


Research on advanced safety devices are in full swing at Autoliv as well as Jaguar/Land Rover, paving the way for futuristic solutions

Nicodemo Angì

The name Autoliv may never have been heard by most readers, yet the company has a long tradition in the field of vehicle safety devices. Founded in Sweden in 1953 by Lennart Lindblad, first as a repair workshop, it quickly started producing creative ideas such as the first seat belts. Worth mentioning are also the first seatbelt tension adjusters, the first side thorax airbag, in 1994, and much more right up until the introduction of the first pedestrian airbag in 2012. 

One of the latest safety devices is in fact the Torricelli Brake, a sort of braking booster named after the great Italian scientist Evangelista Torricelli and his studies on atmospheric pressure and vacuum. Taught by Galileo Galilei in Florence, where he unfortunately died at the young age of 39 in 1647, but not before clinically accounting the vacuum and inventing the barometer, as well as performing important studies and researches in the fields of optics, calculus and mechanics.

 

A very special brake

The Torricelli Brake is a rather original and innovative emergency braking system that uses vacuum to generate a higher braking force. The system is composed of a vacuum induced plate below the vehicle, made with special friction material, which sucks down into the track through an ingenious system of levers. During emergency braking situations – the AEB (Autonomous Emergency Brake) system activates the Torricelli Brake – the vacuum induced plate is dropped to the ground, generating a higher braking force that, according to Autoliv, can reduce breaking distance by 40% in case of emergency. The company proudly claims that this percentage is maintained even in wet or icy conditions. This patented solution uses a 0,3 m2 vacuum plate below the vehicle which, when dropped, produces a down-force of 15000 Newton, equal to a little more than 1,500 kg. A quick calculation shows that the down-force applied is actually equal to 50% of the atmospheric pressure, well within the range of the power braking system. Autoliv has placed a maximum activation speed limit of 70 km/h, which means that the system’s main application will be found in city traffic – just think of the young boy suddenly crossing the road chasing after a ball – or suburban environment.  The system activates in merely 0,1 sec., which makes it far too efficient for current seatbelt tension adjusters that must obviously be redesigned; this has not prevented, though, a number of vehicle manufacturers from expressing their interest in this revolutionary braking system.

Further innovations, promised by Autoliv, relate to radars - a very promising segment in vehicle safety devices -and vision systems.

 

Object tracking radar systems

Radars are very sophisticated sensors, and even if most people associate them with huge rotating antennae on ships or in airports, these devices appear as rather anonymous little boxes on motor vehicles. A radar can measure critical variables such as angles, distances and speed and this information, if properly processed, can alert drivers to possible dangers ahead or take countermeasures, such as automatic steering or braking if the driver does not act promptly.

Radars can retain their accuracy in total absence of light as well as in adverse weather conditions, a great advantage indeed. They send high frequency signals (tens of Gigahertz, 1 Ghz equals to 1 billion wave frequencies) that bounce back, like an echo, from objects ahead or around the vehicle, so as to track and detect the nature, position, speed and direction of these objects, warning the driver of a potential collision or triggering electronic stability control interventions.

Autoliv’s radar sensor portfolio includes: 25 GHz Ultra Wide Band Radar, 24 GHz Narrow Band Radar and a 77GHz Multi Mode Radar.  Blind Spot Detection, Rear Cross-Traffic Alert, Lane Change Assist, Forward Collision Warning, Autonomous Emergency Braking and, last but not least, Adaptive Cruise Control are some of the wide range of applications of radar systems, reason why they are to be found on a large number of manufacturer’s catalogs.

 

Smoothing out the ride                                                            

A further system in line with the times is the Pothole Alert by Land Rover, a detection and sharing platform that, through advanced and sophisticated technology, can detect any road surface “imperfections” ( clearly euphemistic ) and share this information via a cloud.

These new technologies, to be tested on a Range Rover Evoque, will detect position and degree of danger of potholes, manhole covers not properly closed, sidewalk and driveway gratings. The vehicle’s active suspensions will thus be regulated, within thousands of a second, so as to better absorb the holes and bumps along the way.

It does not end there though, the acquired information can, at this point, be shared with other motorists via a cloud in the form of alerts, warning others of the presence of potholes or other dangers on the road. Researchers and the City of Coventry are also considering the option of sending the data – such as position and degree of danger – to local competent authorities in order to improve the speed and efficiency of road repair operations. Mike Bell, Connected Car director for Jaguar/Land Rover, observed how “currently the Range Rover Evoque and the Discovery Sport, both equipped with MagneRide active dumping systems, are equipped with sensors for real-time mapping of the road surface to monitor the response time of the dampers: these can be regulated, thus guaranteeing a fast but smooth handling that irons out road imperfections. Information from these sensors can already be considered Big Data that could be shared with other motorists, but these scanning operations of the road ahead of the vehicle are already the pillars of autonomous vehicle projects. We are developing systems that will allow, in the future, to automatically avoid potholes without sudden and dangerous lane changes, or alternatively to soften the impact by slowing down the vehicle. This will eventually develop into a safe and enjoyable autonomous ride”.  

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