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Carburettors are widely used for control of Air/fuel mixture in 2/3 wheeler vehicles in India as well as other countries. Carburettor technology has improved over the years to meet stringent emission requirements as well as fuel economy demands of customer. With the introduction of Euro-III regulations in 2006 and proposed BS IV requirements in India, emphasis is laid on the transient control capability of carburettor. A project was undertaken at Ucal Fuel Systems to understand the transient characteristics of carburettor and develop electronic control to achieve programmable control of Air/Fuel ratio on the driving cycle. Several tests were conducted on carburettor flow test bench and on chassis dynamometer to understand the transient control response and develop control strategy. It is observed that the Air/fuel ratio measured at steady speed trials, have a marked influence on the transient Air/Fuel ratio behavior as measured on drive cycles.

Year 2000 emission norms for Indian passenger cars, which have been notified requires major changes in the existing technologies being used in the passenger car vehicles on roads. Electronic fuel injection systems and catalytic converters are being used extensively abroad to meet stringent emission regulations. Even in India, major joint ventures in passenger car segment have introduced vehicles with single-point / multi-point fuel injection systems. It has become difficult to meet the mandated emission regulations with the conventional mechanical carburetted vehicles. Automotive Research Association of India alongwith M/s UCAL Fuel Systems has developed an electronic feedback carburettor system to use alongwith catalytic converter for a passenger car to meet the year 2000 emission norms. A closed loop system has been designed and developed which takes the input from a λ-sensor output and controls the additional air added in the intake manifold of the engine through a stepper motor.

The simple design and low cost of the carburator makes it an attractive proposition to be used for two-wheeler applications in India and other countries. However, stringent emission standards pose greater challenge in carburator matching for different vehicle applications. The use of electronics for controlling the air-fuel ratio in a carburator with closed-loop control to meet Euro-III standards is the driving force to undertake this project. The goal is to achieve the best catalytic converter efficiency when the air-fuel-ratio is maintained at stoichiometric within a close band. Inherent variations in manufacturing of carburators can cause the air-fuel ratio to drift from stoichiometric and have an adverse effect on catalytic converter efficiency. The most efficient method of maintaining air-fuel ratio within a close band near stoichiometric is through closed-loop control. This method is widely used in passenger cars with fuel injection.

Automotive emission regulations in India are becoming stringent day-by-day. With the deterioration of air quality, the new techniques suitable under Indian condition to reduce the emissions from automotive vehicles are becoming extremely important. In India large percentage of the vehicle population is 2-wheeler vehicles using a mechanical control for the air/fuel ratio. A project was undertaken to develop the simple Electronic Control System (ECS) for 4-stroke 2-wheeler vehicles. With the unleaded petrol available in the India, catalytic converters are becoming popular and are used on almost all passenger car vehicles as well as 2-stroke 2-wheeler vehicles. Efficiency of the 3-way catalytic converters is optimum for all the three pollutants provided the Air Fuel (A/F) ratio is maintained at the stoichiometry. It is very difficult to maintain A/F ratio at stoichiometry with the mechanical controls presently used.

The electronic content in an automobile is ever increasing for last several years due to emissions, safety and performance requirements. The complete development cycle of an electronic controller needs to be compressed to introduce new vehicle models in the market ahead of time. Antilock Braking System (ABS) ECU is one such example which has become a standard feature for most of the vehicles due to safety considerations. A project was undertaken to develop ABS ECU strategy from concept to vehicle trials with Model Based Development (MBD) technique. A methodology is established for scalable, fault tolerant, proven, and quick to implement ECU strategy development. This paper presents the development cycle followed for a unique ABS controller.

Electronics is widely used for improving the vehicle safety due to its characteristics like fast response, multi sensor interface and implementation of complex control strategy. Already a majority of vehicles are fitted with some kind of Electronic Stability Program (ESP) system in many countries to improve safety performance. Yaw stability is one of the major elements under ESP system. A project was undertaken to develop Yaw Stability Control (YSC) strategy. YSC strategy development is very challenging due to several issues like dynamics of event, ability of brake hydraulics and /or Engine torque controller to respond, proving of the strategy under different user scenarios etc. This paper describes the challenges faced and solutions tried out while development. The paper presents the YSC controller strategy, different regulatory requirements, test data and results with and without YSC on a typical SUV vehicle. The controller has been developed using Matlab Simulink environment.

This paper describes the engine mapping work carried out on a 2.1 litre carburetted petrol engine.The purpose of this work was to improve upon the emission levels of the engine to meet 1996 emission norms with sufficient margin and to achieve best fuel economy possible. This paper deals with the strategy for the selection of speed load points required for mapping depending on engine operating zones, engine base data collection, methodology followed in engine mapping, variation of engine performance and emissions with respect to air/fuel ratio and spark timing etc. Further the mass emission predictions for different strategies like leaning the air/fuel mixture, retarding the ignition timing etc. are also discussed. Recalibration of the carburettor based on the above findings, its effect on vehicle performance are dealt with.

Chassis dynamometers are required for different types of regulatory tests like emissions, fuel consumption, etc. as well as for different development tests and running-in of vehicles. With the stringent emission regulations, the chassis dynamometers are required to simulate road resistance accurately and consistently to get repeatable results. This paper describes the new concept of chassis dynamometer using two power devices, an eddy current dynamometer for absorption and a DC machine for generation. Both the machines are controlled through a personal computer (PC) with necessary interfaces. It has been possible to simulate the road resistance accurately on different driving cycles. The software developed has all the required modes for operation. The detailed results are presented in the paper.

Autonomous driving is looked upon as solution for future of automotive vehicles. The technology has tremendous possibilities to improve safety, fuel economy, comfort, cost of ownership etc. The project to develop an autonomous controller from scratch was undertaken, with objective to drive under selected test scenarios. The car, modified to drive using this autonomous controller, is able to handle these scenarios. The key scenarios include ability to successfully drive on tracks with well-marked lanes, Follow the route as per selected trip plan file, recognize and follow all traffic road signs, traffic signals en-route, identify other vehicles on the road or pedestrians in the lane and take the appropriate action. The development was carried out using frugal engineering approach. As the Autonomous Vehicle technology is still under development, the standard proven published approaches are not available.