the venkaman's blog: Stop-start technology for automobiles

Introduction

India is slowly emerging the “next big thing” on the global scenario. In its current form and direction of development it will soon emerge as one of the new global markets for the global sales and production. One of the biggest areas to grow in this sense is the car industry.

An increase in average salaries by well over 20-25% in the last fifteen years has created a situation where a car is no longer a luxury but a necessity. This has created a situation where the Metros alone to add around one lakh cars to the road system each annually. In terms of global production we are the 9^th largest car industry globally producing up to 2.3 million vehicles annually.

Poor and short term road planning during the development days of the country has resulted in a road system of just fewer than 50% of both highways and city roadways. We have been unable to cope with the phenomenal growth that has occurred resulting in traffic jams and massive congestions country wide. Along with around a lakh of cars we are also adding almost the same number of two wheelers to the road system creating a situation of complete chaos and disorder.

These traffic jams leave large carbon foot prints by means of massive amounts of exhaust fumes. The Suspend particulate matter (SPM) in the capital city of New Delhi is almost thrice of what it was ten years ago. It is a known fact that SPM of less than ten microns has become very common. Such kind of increase causes various problems like lowering the air quality and causing respiratory problems for humans and animals

Affecting factors

Pollution is the only contributor to congested roads. Along with poor planning and excessive vehicles, our driving tests are not through enough and effective in weeding out the drivers from those legalized to murder behind the wheel.

To fix or reduce such a problem we require long term solution which must involve careful planning and distribution by the government and private players. This long term solution generally involving the control of production vehicles and re designing of roads and may take more than fifty years to be planned and put into action.

For the current time the issue that are faced by the road makers and managers must be tackled with short term and quick solutions. One of the fastest and most effective ways to reduce pollution from mobile and immobile vehicles is to cut down tailpipe emissions. The most obvious solutions to these are vehicular developments like the Toyota Prius which is a hybrid car employing a small petrol engine and Lithium Ion battery electric motor, alternative fuel vehicles like the Tesla and the Chevrolet Volt which use electricity.

Employing a more efficient design for the vehicle so that it can make use of aero dynamics to overcome what has been lost in horsepower. The solution seemingly obvious has one major draw back that is it costs too much. Each of the above mentioned vehicles sell for nothing less than $20,000 which when brought to a country like ours will turn out be way more than the average man can afford.

Stop-start technology

In such a situation a change in the systems we use is much cheaper and more effective. The stop-start system is one such technology. In its most basic form it controls the ignition of the engine after a specified time period. This is useful in long traffic stops where the engine consumes huge amounts of fuel without moving the car.

The generic term for this type of vehicle is known as a Mild Hybrid or in India as a Micro hybrid. In a Hybrid vehicle the car comes with two separate engines one electric and one petrol/diesel powered. The electric motor is used to run the car for most of the time while the fuel powered engine serves to act as a backup or generator for the electric.

In a mild hybrid the vehicle is classified and put into the category of a regular internal combustion model. The electric motor simply acts as an assist but cannot propel the engine on its own. When the vehicle is moving at a constant speed, or has stopped for a long period (generally kept to be over thirty seconds) the electric engine steps in and runs the car. Nowadays it also makes use of regenerative braking whereby when the brakes are applied the energy from the process of braking is converted into electricity and stored in a battery.

This kind of system though not fully efficient is very effective because it gives a saving of around 10-15%. Such vehicles also cost less than conventional hybrids because they are cheaper to produce and maintain. It is not one single system that works but rather a combination of smaller system, which in the larger picture allows for a good fuel saving. The vehicle basically has an economy mode. In this mode all the various smaller components work at their highest efficiency. The electric motor is anywhere between 30-40 volts and helps in running other electric components like the lights stereo and AC.

History

One of the first vehicles to employ this kind of technology was the Volkswagen polo in 1984. This was a system in its most basic form and did not do much to improve the car’s running efficiency. Deemed to be too expensive for its time it was not very successful. The entire system came to play in the year 2006 when Citroen introduced the ISG (integrated starter generator) technology into its cars the Citroen C1 and C2. This form of system basically combined the starter and alternator into unit making it more compact and efficient.

Latest Development

Japanese auto maker Mazda one of the latest entrants into this field has introduced a system in collaboration with Bosch of Germany. It employs a combination piston and clutch positioning for maximum efficiency. This system known as SISS (Smart idle stop system) or I-stop in foreign models has proved in testing conditions that it will save up to 15% of fuel for the car.

In India Mahindra has introduced this system on its Scorpio Model calling it the “M-Eagle system” it works along the similar lines of the micro hybrid system.

Drawbacks

Such a system is not without its drawbacks. Emerging at the top of the list is the fact that though it costs lesser than a regular hybrid or alternate fuel cell car it still cots more than the regular model of the car that it has been placed on.

With the current cost of petrol and diesel worldwide, the actual saving on the vehicle may turn out to be quite small. The extra weight of the hybrid train generally increases the drag coefficient of the vehicle.

For the future

In the larger picture this system will become effective if it is applied to a larger number of vehicles like buses, autos which are notoriously fuel inefficient but need to exist because they are basic forms of public transportation. The existing models can be fitted with such systems, which are available independently, if the fitting is subsidized by the government. A little bit of effort from everyone will take the nations car using population a long way towards greener, cleaner and safer roads.