Energy Transformation in Braking

The common misunderstanding in braking is that the kinetic energy in the vehicle will be transformed in to thermal energy due to the friction in brake pads and the drum. It’s true that part of the kinetic energy will be transformed in to heat, but a large part of it will be transformed in to potential energy in front suspension. You definitely must have noticed that, the front suspension system gets compressed and vehicle leans forward whenever you apply breaks. That’s the actual transformation of Kinetic energy in braking process.

Kinetic Energy –> Potential Energy in Front suspension and thermal energy

The above power transformation will depend on the friction between the road and the wheel. If it was lesser than the friction between brake pads and the drum, wheels get locked and vehicle starts to skid. This is the reason why vehicles skid in slippery roads. Further in the case, front suspension gets totally pressed and when it has no capacity to store any more potential energy, the same thing will happen.

Why Do We Need ABS?

When you apply breaks on a road, part of the kinetic energy will be transformed in to thermal energy as usual and part will transform in to potential energy in suspension depending on road friction. If the road is slippery or in other words having less friction, vehicle has a lesser chance of transforming kinetic energy in to potential energy. Hence there will be a greater chance of vehicle getting skidded. If the vehicle stars to skid, there is no way to control the nose direction using the steering wheel.

As a solution some of the experienced drivers pedal the break is such situations. I have seen some drivers using the same technique to stop the vehicle in a shorter distance, without losing control in slippery roads. What exactly happen there is once the vehicle starts skidding they release the break pedal, so that the front suspension gets a chance to release its potential energy. After that the driver applies the break again so the suspension can store potential energy again.

ABS is an electronic braking system which can perform the above mentioned task more accurately and efficiently. The main objective is to maintain the vehicle speed and wheel speed at the same level. If wheel speed is ’0′ and vehicle speed is more than that, it means the vehicle is skidding. The simple technique used in ABS is, once the wheel speed reaches ’0′ it releases the break to measure whether there’s any vehicle speed left yet. If that be the case, wheels will start again, and front suspension will get released from its potential energy. Then ABS automatically applies break and will continue the same procedure till the vehicle speed and wheel speed both become 0.

Advantages of ABS

The main advantage is you will be able to stop the vehicle in a shorter distance since it utilizing the energy transformation to the maximum level. And it won’t let the vehicle to skid understanding the road conditions. Therefore you can apply full break in any road condition without any hesitation. As long as wheels are not getting locked, driver can head the nose of the vehicle to desired location while applying full brakes. This will reduces the driving stress significantly since we don’t have to concern about the amount of break we apply in any road condition.

Evolution of ABS

In the early stage of ABS it had very few signals to control its behavior. It calculates the wheel speed and captures the vehicle speed by releasing breaks while wheel speed is 0 through the same speedometer. And it treats all 4 wheels the same way. This system worked fine in general road conditions yet there were identified problems. In the case of vehicle is driving down a hill, the vehicle speed will never be 0 while it release the break to capture it due the energy transformation from potential energy to kinetic energy. Hence there was no way to totally stop a vehicle which is driving down the hill by using break paddles. The problem were quickly solved using a simple logic that if wheel speed were less that certain level it will be locked by break till the driver releases the break paddle.

Additionally, if all four wheels are not in same road conations, this kind of break system yet result a skid. If two wheels are on snow and others on clean road, once the driver applies break it will turn the vehicle in an uncontrollable manner no matter it has ABS. Having the objective of solving this problem modern ABS systems collect data separately from all four wheels and apply ABS accordingly.

In traditional ABS systems collect the vehicle speed data from the same speedometer while uses to collect wheel speed data which is not always an accurate a mechanism. It always requires releasing the breaks and letting the wheels to spin to capture the relevant data. Modern ABS system are been designed to capture the vehicle speed using GPS data which could be identified as a proper mechanism, yet it could be less accurate. However, it doesn’t require releasing the break to capture vehicle speed.

Advanced Application

Security has become one the major concerns in modern vehicles. In order to provide maximum safety, braking plays an immense role. The main objective is to leave no chance to human errors on the road. Therefore Anti-lock braking systems will continue to evolve. The modern ABS algorithm and computers collect wide set of data to control the behavior of the ABS functionalities. In the early stages it was just wheel speed and vehicle speed. Modern ABS systems are equipped with many sensors in brake pedal, all four wheels and the accelerator as well. They could be designed to capture weather conditions as an input signal to the algorithm to make it even accurate. The Electronic stability control which could be identified as an extension of ABS, applies breakings separately to each wheel using advanced algorithm which helps the driver to keep the vehicle on the track at greater speeds and on sharp corners. Recently ABS systems are plugged in to motorcycles and result was more than 40% lesser accidents.  If your vehicle is also equipped with ABS and it’s well maintained, you don’t have to worry about skidding or controlling it when you apply breaks. All you have to do is just push the break paddle. ABS computer will do the hard part for you, and ensure maximums safety for your baby vehicle.

References

• www.caranddriver.com. (2010). Decade in Review: Technology – Gallery. Retrieved January 2011, from www.caranddriver.com: http://www.caranddriver.com/var/ezflow_site/storage/images/features/09q4/decade_in_review_technology-feature/gallery/electronic_stability_control_3a_mercedes-benz_electronic_stability_program_illustration_photo_27/3133644-1-eng-US/electronic_stability_con

The problem in the previous system were

• Direct changeover
• Consequences in system failure
• No Driving fun

Let see if we will decentralize controlling, how it will solve all these problems. In this concept all the vehicles will be intelligent agents. Like every other human who are driving a vehicle sitting behind the wheel. In addition to that the cars can communicate with each other. In previous system all the decisions would be taken by the central controlling point. In here they will be taken by the cars themselves.

Ex: Car B is following car A. Car A going to turn left after 1 KM. Previous centralized system, that information will be uploaded to central server and it will make the car B aware. In this decentralized system car A will directly talk to car B and say “Hey dude! I’m going to turn left after 1KM” so based on that information car B can take steps.

Sounds cool ah! But still there can be a central server to update cars about general conditions of the roads including traffic and maintenance. And just assume, only your car is having this system. No problem, it can use its camera, radar etc and drive alone thinking all the other cars are driven by humans. With the increasing number of this kind of intelligent cars, system will come to live step by step. No need of direct change over. In the case of central server failure it won’t affect the system badly. Still cars can drive communicating each others.

That’s how this decentralized system is going to solve the problem of changeover and how it will react to a system failure. But how this is going to solve the problem of “Driving fun”?

There is a simple solution. “Manual override!”. If driver want to drive by himself, he would be able to override the system manually and continue driving. In that case all the other cars around will be notified that this car is manually overridden. So other cars can take appropriate security steps, because a human is behind the wheel. To make this even better, there can be some busy city areas where manual overriding is prohibited. In permitted areas drivers can have fun.

This sounds like an awesome system, but when it comes to implementation, there are many technical challenges. Still there is no good enough intelligent system to drive a car on a real road. Communication between cars wouldn’t be much harder. It’s just matter of introducing common protocol. Once we come up with a good intelligent system to drive a car, we are almost done.

(Special Thank : Shyam Mehraaj Reyal)

References

• (n.d.). Retrieved from http://www.mjnet.us/recen_t_projects_files/traffic_control_center_long_island_city_queens__traffic_moni.jpg

Just think, if everyone on the road will perfectly follow the road rules, In that case there won’t be any traffic. But humans are controlling vehicles and we are not that perfect. So is there any perfect one to control traffic. Yes, a computer. I actually saw this in the movie “Minority report”. This is a Centralized Traffic Control System. All the vehicles are connected to a centralized server and it control everything on the road. And the best part is the server knows positions of each and every vehicle, so it can move two vehicles nearby on the same track with the speed 120 Kmph, maintaining very narrow distance between them. And the same thing can be applicable to ‘n’ number of vehicles. On top of all, just assume the vehicle in front of you going to turn left in next junction. In general situation the driver on signal light in left and indicate that. But in this kind of system, the central server knows that the vehicle going to turn left and it can control other vehicles behind that accordingly. This sounds like a dream, but not impossible. We already have GPS and maps on our vehicles. All we have to do is update those details and get driving instruction from the server and execute them.

Once this kind of system will come to action, there won’t be a Steering wheel in vehicles. That space also will be allocated for passengers. The passenger will have to enter the destination once he gets in to the vehicle and those details will go to the central server. The server will give the vehicle a rout considering all the factors including other vehicle routs etc. Finally vehicle will reach the destination without human involvement. And it’s so difficult to find a parking space in modern busy cities and it’s a real pain to many people. But one day with this kind of system, once you go to office, you can tell your car to go home and come back when you going to finish the shift.

This will be a bad news for auto lovers. So sad that manual driving is no longer permitted. And you can’t drive over speed, break the law and have some fun. No more manual shifting, drifting, drag, street racing or anything. This is going to be kind a boring yes.

One possible problem in this kind of system is servers are always going down. Under any conditions we can’t guaranty 100% up time. What will happen if the central server (Probably the Server Cluster) will go down? Yes we can design the system to stop all the vehicles, but can we afford that delay?  On top of all, what will happen in the case of bug or defect in the system? The possible damage will be massive and probably cost many human lives. And how far can we expand this system? When it comes to implementation we have to go for a direct changer over. Is it possible? The engineers will have to find solutions for all those problems before this kind of system comes to live.

References

• (n.d.). Retrieved from http://www.wired.com/images/article/full/2007/10/FAA_630x.jpg