Dr. Ajay Babu
@nssce.ac.in
Assistant Professor
NSS College of Engineering Palakkad
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Abhinandan panda, Srinivas Pinisetty, Partha Roop, Ajay Babu K, and Sabarimalai Manikandan M
ACM
The modern technological advances allow IMDs to be accessed and controlled wirelessly, making them more vulnerable to a variety of security attacks. In this work, we propose a new approach of dual input channel to the runtime monitor that takes both ECG and PPG sensing techniques to monitor safety policies of an IMD. The monitor can be deployed on a wearable device that senses ECG and PPG signals non-invasively to verify if the IMD is not diverging from a safe baseline. We present the formal dual input channel monitor synthesis framework. Our experiments using the Pacemaker safety policies validate the developed correlation of ECG and PPG signals, and the proposed runtime monitoring approach.
Ajay Babu and S. Ashok
Elsevier BV
Abstract Fuel economy improvements and battery energy savings can promote the adoption of parallel mild hybrids for urban driving conditions. The aim of this study is to establish these benefits through two operating modes: an energy saving mode and a fuel saving mode. The performances of a typical parallel mild hybrid using these modes were analysed over urban driving cycles, in the US, Europe, and India, with a particular focus on the Indian urban conditions. The energy pack available from the proposed energy-saving operating mode, in addition to the energy already available from the conventional mode, was observed to be the highest for the representative urban driving cycle of the US. The extra energy pack available was found to be approximately 21.9 times that available from the conventional mode. By employing the proposed fuel saving operating mode, the fuel economy improvement achievable in New York City was observed to be approximately 22.69% of the fuel economy with the conventional strategy. The energy saving strategy was found to possess the lowest payback periods and highest immunity to variations in various cost parameters.
Ajay Babu and S. Ashok
Elsevier BV
The major challenge to the large-scale commercialisation of hybrid electric vehicles is their high initial and operating costs, although a mild hybrid is generally cheaper than a full hybrid of the same performance. Hence, the average operating efficiency of the internal combustion engine of a parallel hybrid and the energy saved by its battery modules when running on urban roads have been key research subjects. In this paper, a method for maximising the performance of heavyweight hybrid vehicles is proposed. Because the manipulation of the thresholds of the state of charge window of the battery of a parallel hybrid affects the performance of the vehicle when using the commonly employed electric power-assist strategy, we developed a method for determining the optimal sizes of the vehicle components that afford the most feasible operations using the conventional and modified power-assist strategies. Furthermore, the performances of the vehicle in both modes were analysed for various urban driving conditions representative of those encountered in the USA, Europe, and India. The results showed that energy saving in the battery pack after a typical urban driving cycle was higher in India than in the USA and Europe. The saving in India was determined to be 3.34%, whereas those in the USA and Europe were 3.13% and 0.23%, respectively. The energy savings in the battery pack of the same vehicle under identical conditions were determined using a simple internal resistance battery model and a resistance–capacitance battery model. The performance of a typical parallel mild hybrid capable of operating in the modified power-assist mode was also compared with that of an equivalent internal combustion engine vehicle presently on the Indian market.
Ajay Babu and S. Ashok
IEEE
The vehicle range provided by a fully charged battery module in any electric vehicle is no match to the range provided by the internal combustion engine driven vehicles with full tank gasoline or diesel. This limitation of electric vehicles paved way for the evolution of hybrid electric vehicles. Among the various known architectures for hybrid electric vehicles, the parallel mild hybrid is expected to be the right candidate to be introduced in a developing country. This is because the size of the electric powertrain in such vehicles shall be relatively smaller compared to the other vehicle architectures and hence shall be less costly compared to the electric vehicle or other hybrid electric vehicle configurations. This paper aims at explaining the procedure of deriving a parallel mild hybrid vehicle equivalent to Tata Safari, a passenger vehicle already available in Indian market. The paper also compares the performance specifications of both vehicles and determines the losses in the proposed vehicle during the normal cruising mode and regenerative modes while traversing a typical Indian urban driving cycle and an Indian highway driving cycle.
Ajay Babu and S. Ashok
IEEE
Voltage source inverter based drives are known to be smaller, reliable, and efficient and have relatively fewer issues than current source inverter based drives. However, in recent times impedance source inverters appear to be a promising candidate for these applications, as they carry the advantages of both voltage source inverters and current source inverters. This paper presents the performance of a T source inverter based vector controlled drive in a parallel mild hybrid vehicle. A T Source Inverter is a type of impedance source inverter with fewer passive elements. The performance of the drive is validated through a typical driving pattern which is most likely to be experienced by parallel hybrids utilizing electric power-assist strategy. The performance of this drive is also compared with a voltage source inverter based vector controlled drive for 22 seconds of a typical Indian urban driving cycle. The results of these analyses along with the performance of the proposed drive on initial parts of typical urban driving cycles in the US and Europe, helps in confirming the suitability of T source inverter based drives in these vehicles.
Ajay Babu and S. Ashok
IEEE
Energy saving in Hybrid Electric Vehicles is largely identified as a major means of promoting them. Induction motors are used widely in these vehicles and hence the inverter based drives used in these drives are also an area of continual research. This paper presents a comparative study between the Voltage source inverter and the T source inverter based drives used in parallel hybrids. The advantages of T source inverter based drives in these vehicles are proved through this paper.
Ajay Babu and S. Ashok
IEEE
As part of the electrification of transportation sector, electric vehicles were the first to be developed, followed by the hybrid electric vehicles. The current study analyses the weights and performances of vehicles, with component sizes optimized to meet a common set of performance indexes. The battery pack in electric vehicles is observed to be 2-20 times heavier than the lightest vehicle of the same class. This paper finally presents a flowchart for general selection of vehicle configuration. The validity of the proposed algorithm is ascertained by analysing the performance and vehicle configurations of some vehicles already existing in the market.
Ajay Babu and S. Ashok
IEEE
Worldwide research is concentrated on making the Transportation Sector as environment friendly as possible. Replacing the IC Engine driven vehicles with Hybrid Electric Vehicles shall reduce the adverse impact of transportation sector on environment in a big way. But, there are inherent trade-offs between the battery goals for HEVs. Research is focused on developing a battery technology which satisfies these goals in a much better way. It can be observed that the present day battery technologies have many good performance characteristics, but have environmental issues associated with them. It is indeed a challenge to find a battery technology which has the best performance, while has a minimum environmental impact. This paper proposes a novel index for selecting the battery based on performance and environment friendliness.
Ajay Babu and S. Ashok
IEEE
A lot of research in the area of automobiles is focused on Hybrid Electric Vehicles (HEV) and Plug-in Hybrid Electric Vehicles (PHEV). The concept of PHEV becomes meaningful only if the system as a whole is efficient. Inorder to build an efficient HEV, it is important to select the best components and of the correct rating. Motor and Battery are important components in any HEV. This paper describes the procedure to calculate the maximum power requirement of any HEV. The features of two most popular motors used in HEV are discussed. Various HEV architectures are also explained briefly in the paper. This paper proposes an algorithm for motor selection and selection of PHEV architecture based on overall efficiency. The algorithm also ensures that motor is not oversized or undersized for a particular vehicle.
Ajay Babu, S. Ashok, and R. Sreeram Kumar
IEEE
Increased demand for non-polluting mechanized transportation has revived the interest in the use of electric power for personal transportation and also reduced reliance on petrol or diesel driven automobiles. Moreover the fast depletion rate of petroleum & such conventional energy resources have forced mankind to lay much emphasis on the concept of Energy Conservation. This paper makes an effort to divert the attention of mankind more in this direction. A low cost alternative to an automobile is a bicycle. However, the use of bicycles has been limited to very short trips or as a recreational activity. This paper presents preliminary design aspects and simulation analysis for a Fuzzy Logic Controlled Hybrid Bicycle.