Vehicle Safety Systems - In depth analysis of what technology can do and why are we letting the monkey drive
We are all passionate about technology and cars and some of us know about how your vehicle can technically protect you in case of an accident, but what can a vehicle do to avoid an actual accident from happening? Can we expect a paradigm shift on behalf of the new technology being available?
According to the European Commission there were 25000 deaths in Europe in 2016. There is a clear reduction in deaths from the 60000 in 1996, but most of the reduction until now was due to airbags, passenger cells and crumple zones, all physical systems that help the passengers in case of a violent crash. Although the introduction of the ABS ( anti-lock braking systems) and ESC ( electronic stability control) helped a lot, the new technology has given us a lot of more possibilities to completely avert the accident, before it even happens.
Fighting the misconceptions
Before talking about any technology, we need to understand what is the weakest link of the whole car driving system.
Let's take a simple braking operation. You are driving at 90 km/h (55 mph) - the usual European speed limit outside of urban areas. As you are driving in a straight line on a clear road you pay less and less attention to the car in front, from which you keep a 50 meters distance (about 10 car lengths). It looks safe enough as you are a good driver and have good reflexes and your car is in good shape.
What you don't know is that the car in front is tailgating another car, whose driver has decided to take a left at an intersection so he slows down faster than usual and turns on the left signal.
The tailgating car will either slowly hit or stop just short of the car in front. You are now presented with the worst situation in traffic in my opinion. You will see why
The assessment + decision + reaction time + braking
As you are minding your own business your sub-consciousness sees the distance dropping and it will eventually raise an alarm. The timeframe from the point of observing the car in front until the prompt for swerving or braking is 0.5-1 second.
- Is it dangerous?
- Is swerving an option? Is anything coming from the front?
- Can I avoid it through the right?
These decisions take time.Another 0.5-1 second, depending on how good your awareness of the situation was since you can't look in the mirror in such a situation. If you are tired or driving for a long time you will take more time. You could instinctively brake but you will still take this time to react and decide if this is one of the instinctively brake scenarios.
For now you have wasted a minimum of 1 second, possibly more. At 90 kph this means that your car traveled an additional 25 meters and you haven't even started to brake.
It will take another 0.25-0.5 to actually move the foot on the brake and apply it fully.
To completely brake on dry surface and with good brake calipers, discs and tires from 90 kph, an additional 32 meters will be needed. This gives a stopping distance of 57 meters, much more than the initial distance of the vehicle.
The science behind the calculations was taken from here .
Reducing the "Aw factor"TM
The car makers are building better and better brakes which can reduce the stopping distances, but technology is being used at the maximum. The stopping distance was tremendously reduced from the 60's, by using better rubber for the tires, better materials for the brakes and for the calipers. Vented braking discs are now present on all car models. What hasn't changed in many years is the driver. Although traffic laws and preventive driving have decreased the occurrence of the critical factors that make a crash possible, the weakest link that can't be improved in the short future remains the "monkey" pushing buttons inside.
Autonomous vs Assisted Driving
I like to drive, I would love to have a Tesla and perhaps I will buy one in the future, but I wouldn't like to be forced to be a passenger. The talk of an autonomous car is something that I won't be doing now, there are a lot more in play there. I am just trying to see if the driver can be assisted efficiently to reduce this kind of dangers.
Assisted driving usually means that a computer and sensors are being connected and are put to analyze the driving conditions and the car surroundings in order to prevent or minimize the risky situations that occur during the drive.
The basic unit for a computer speed is measured is MHz (Mega Hertz or Million Hertz) which in computing stands for million of instructions per second. So having a computer taking split second decisions is a good decision :)
This is one of the best systems to have on your new car. The system uses a camera or a LIDAR (which is a light RADAR), to feed data to a central computer. Special software is being run on the computer to analyze the distance from any object in front, or in case of a camera to identify if the car is getting closer or not.
The speed at which both cars travel is being analyzed and taken into account and some systems even use artificial intelligence to recognize cyclists or other cars, pedestrians or traffic signs.
Source: Creative Commons - Youtube
The system works even if the driver applies the brakes too lightly, without any sound warning or if the driver is not paying attention he is first warned via an audio warning and then brakes are being applied. The system is now at its second generation, which means that it can avoid collisions up to 60 kph (37 mph) of speed difference between the two objects.
Most of the car makers are using this system so if you are in the process of buying a new car, be sure to check it first. Some car makers make the system available as part of bigger or exclusive equipment packs to cover the cost, but most of them have it by now.
Lane Departure Warning + Assist
Another kind of new system which involves a set of cameras in the rear and front bumper to analyze the lateral and rear traffic and the lane markings in the front, corresponding speeds and feeds the data to the central computer. The system can manifest in one of the following ways:
- If the driver fails to use the lane change indicators and just slides over to the next lane, the system will issue a warning sound and if the system allows it, will even brake the wheels opposite of the sliding direction to compensate and/or turn the wheel back to the original position.
- If the driver uses the lane change indicators but the lane chosen is not empty of traffic (the cameras can predict that a car is going to overtake shortly) then a light will be flashed next to the external side mirror along with a sound warning the driver of the situation. If the driver does not cancel the lane change or even if he goes along with it, the system will prevent the lane change so that the wheels will never cross the lane lines.
Traffic Sign Recognition
This is a basic system, it involves a camera to analyze the traffic signs and displays them on a HUD (heads up display) in the car in order to help the driver keep in mind what types of restrictions are on that specific road. It usually is not connected to the main computer, although some systems are being developed to do that.
By using the navigation system and an internet connection, the whole world can be mapped by the cars and the data can be stored in the cloud. When a driver wants to take a left through a restricted road, the system can prevent it. Some accidents happen on the highway when drivers use a wrong ramp and end up on the wrong way, driving fast head-on with the usual traffic.
Traffic Jam Assist
This is a very complex system which analyzes the traffic in front, rear and sideways. It is the most advanced system, setting aside the autonomous driving modes. It uses LIDAR to keep a specific distance from the car in front. This is only able to install as an optional equipment on automated gearbox. The car will basically follow the car in front at specific distances, either preset by the manufacturer as (close,medium,far) or controlled via a dial in meters or feet. The car will brake as the car in front brakes and it will speed up as the car in front speeds up. However it will not follow the car sideways, but instead it will follow the lane. So if the other car departs the lane, the car will just accelerate until it follows the car in front.
A nice detail about the system is that the car also monitors the car behind it and if the distance is dangerously low and there is a risk of a crash, it will accelerate towards the car in front and brake safely so that it keeps the car equally spaced from both the surrounding cars.
Rear wheel steering
Rear wheel steering was originally included on limousines and otherwise long cars as to facilitate a smaller turn radius, but in the last years as the technology progressed it is starting to be used as a safety mechanisms. We might have experienced a hole in the road at high speeds, trying to avoid it would cause the car to swivel aggressively. This happens because the steering gives the car a rotational acceleration. Having a steering system on all four wheels allows the car to just turn all the wheels in the same directions and "scoop" over the hole in the road without that rotational movement. Parking in small spots while also protecting the rims is a plus.
Source: Youtube - Creative Commons
Adaptive and beam forming LED Lights
The first generation of adaptive lights were just turning along in corners, or just meant having a fog light turn on when rotating the wheel for more than a few degrees, but the technology has advanced. While BMW spent a lot of its money in actuators and motors to swivel the headlights, others have invested a lot in LED fixed subsystems.
The system works by reading the data from the lidar and from the camera, identifying the cars and their position and dimming or switching off parts of the headlight in order to not blind the other drivers and cause them to become a risk for your own car. Additionally it can reduce eye strain in rainy conditions by reducing the water surface light glare. Because of the powerful on board computer and a LED system like the Audi Matrix, a lot of calculations can be done per second and the system can track up to 8 or more vehicles in the same time by simply switching individual LED's on and off. Below you have a demonstration of both the BMW actuator headlights and the AUDI Matrix LED system.
Source: Creative Commons - Youtube
Source: Creative Commons - Youtube
Adaptive suspension as a safety system
The adaptive suspension is a relatively simple idea of making a suspension harder or softer by either pumping air or oil in the shock absorbers. But when connected to a computer and a camera or LIDAR this system can increase the safety. For example after overtaking a car and trying to fall back in you see a bump in the road. You are forced by the incoming traffic to fall back so you will take the bump at a non straight angle, which might send your car into an uncontrollable trajectory. This system would just raise the car suspensions and then soften it right before crossing the bump. This will absorb most of the inertia into the drivetrain and the car will not feel any forces being exerted upon itself.
Another system being used is the lateral impact reduction. In case of an impeding sideways impact, the car will raise its suspension to the maximum, in order to place the lower thicker structural chassis girders in front. If the impact is with an SUV, this will greatly help the occupants.
Sleep and tiredness sensor
A camera oriented at the driver will continuously analyze the frequency of the eye movements and the blinking as well as identify any yawning. The data is compared against the car's database or against the normal human range and if the values are lower which means that the driver is slower in responses it will warn the driver and recommend him to rest.
As the technology improved in the last years and the active safety systems reached a very high tech development phase which reduced the breaking distance to less than a third, the emergence of the driver's reaction time as the main factor in collisions has made the industry to try to tackle this problem. By using the ever-increasing computing power which can take thousands of millions of decisions per second compared to the few decisions a human brain can take, the driver can be assisted in its task, making it almost as safe as autonomous cars.
This approach is based on many fields of research, from Artificial Intelligence to OCR (optical character recognition), from DSLR image sensors to military grade LIDAR and facial recognition. These industries have really taken off and are creating a lot of jobs, at least in my country.I can even see what the future research is about and it is really astounding, the concept of the future transport deserves its own article, as it will deeply change what ownership means and our mentalities as a world-community.
I can give you a list of cars that support some or most of the systems here, a list done for my own documentation into the brands that I was interested in. So while it is a good list, there may be other cars that are not featured here:
- BMW Driving Assistant Plus
- Volvo Pilot Assist
- Audi Driver Assist
- Skoda, Volkswagen, Seat - Traffic Jam Assist
- Toyota - Adaptive Cruise
- Mazda i-ACTIVSENSE
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