Saturday, July 18, 2009

Automobile SUSPENSION of the future


We all have travelled around the world in various forms of transport viz cars,auto-rickshaws,cycle-rickshaws,trains,planes,buses etc. Humans have always sought for comfort, during their travel from one place to another. Various modes of transport have two dimensions which people take into account while they travel viz the comfort level and the cost factor. Unless there is a balance between the two the society would be divided into two segments: the affluent ones and the common ones. The affluent wouldn't mind spending on luxurious travel while the common man is cost conscious. So to provide comfortable travel and to make it available to the common man (aam aadmi) an optimum must be reached.

Automobile suspension systems constitute one of the items that affect comfort levels in a vehicle. The present suspension systems include leaf springs,bogey suspensions, spring type suspensions and air suspensions. While the former ones have been used for many years, the air suspension concept a recent one ( say about 10-15 years old). Air suspensions were invented so that the bumpiness on the roads would be absorbed in the air bellows and less vibrations would be transmitted up the vehicle to the passengers. Air suspensions have done quite a good job in improving the comfort level in automobiles though the concept of vibration less travel could not be met by them. Engineers have experimented with various combinations wrt suspension systems,developing hybrid suspensions (combination of two suspension systems) albeit with limited success to ensure 100% vibration free travel.

The concept of electromagnetic suspension holds a lot of promise to ensure 100% vibration free travel. The concept is very simple: A magnet has two pole ; the North pole and the South pole. Unlike poles attract each other while like poles repel each other. So if the North poles of two magnets were brought close to each other they would repel each other and same would be the case with South poles. The electromagnetic suspension uses this concept. There are two ways of doing this:

Option1: We could use plain magnets with like poles facing each other one above the other. In this case during a bump or a pothole the magnets would tend to squeeze in but like poles would repel,absorbing the shock of the vibration. This design has a couple of drawbacks although a good theoretical concept. First the size of the magnets has to be extremely large because we are talking of an automobile and the forces transmitted up the vehicle would be thousands of Newtons. Secondly if the like poles are not strong enough to repel force which tend to squeeze the magnets together then the whole concept of vibration free travel goes for a toss.

Option2: We could use electromagnets which come into action when electricity is passed through them. These magnets can be made to come into action whenever required or can be made active permanently (which need current to be passes through it at all times). Electromagnets tend to be more superior than permanent magnets because permanent magnets could lose their magnetism after a certain period of time. The magnetic flux could also be controlled by regulating the amount of current passing through the electromagnet. Thus the problem of the like poles of two magnets squeezing each other during a major bump could be avoided. But electromagnets also have their own drawbacks: first we would need a superior battery system to cater to the needs of the electromagnet,giving good performance without draining out quickly,secondly they tend to be more costly than permanent magnets.

We could improve on the electromagnetic suspension system by providing an electronic control unit which constantly monitors the road conditions,giving signals to the suspension magnets and controlling the amount of flux generated between them. The vehicle speed also needs to be regulated when the automobile encounters a bump or a pothole because the speed with which the vehicle hits the obstacle determines the amount of upward thrust on the vehicle suspension system.The suspension system is the key to passenger comfort and also a necessary element in the control mechanics of the vehicle. Electromagnetic suspensions are not used on a mass scale in automobiles because quite a lot of research needs to be done to make it commercially viable and effective rather than keeping it as a theoretical concept but they hold a bright future in ensuring 100% vibration free travel, giving passengers the feel of floating in the air.