Development of Engine Management System - Tata Nano - The Value Car

This paper describes the development of Tata Nano Engine Management System and the related electrical and electronics architecture. The design criteria for the electrical and electronics architecture are discussed in detail in the body of the paper. When the Nano project was first conceived, the existing low cost car in India was not affordable by common people. The Nano project was targeted for a family of 4 which was using a two wheeled vehicle for commuting, irrespective of the season. For engineers, it was difficult to conceive the idea of the Nano vehicle and powertrain. How do you design a benchmark which meets both Indian and export needs and should also be extremely low in cost? There was no low cost car available either for the Nano to benchmark against. It was also clear that the strict pollution regulations existing in India could not be met without an Engine Management System and thus the focus centered on a low cost Engine Management System (EMS). EMS development consisted of two main parts: 1). Hardware : Development of safe, reliable but low cost hardware which meets all requirements and fits in the E&E architecture was a challenge. 2). Software : Finalizing the software requirements, designing and testing all functions within the limited memory and processor speed was critical. The common “V” cycle model was followed for the development of EMS. In Nano, to reduce the development time and cost, modern tool chains were used extensively. The initial phase, called the alpha phase, utilized the Tata Motors (referred to as Tata hereafter) in-house Model Based Design process including HIL testing. In the second phase, the production phase, the EMS system supplied by Bosch was used. Tata performed functional testing of the released production software in HIL, participated in the function design, function review and calibration