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This paper describes the system architecture together with control and diagnostics features of an indigenously developed electric vehicle controller for Light Commercial Vehicle. The key functions of vehicle controller include power management, driveline controls, regeneration and vehicle mode controls. In particular this paper presents vehicle's operational strategy in economy, normal and performance modes based on the vehicle speed and SOC. It also has feature to enable vehicle operation in reduced performance mode at low battery voltages. The battery fault predictor algorithm is also described in detail that is used to control discharge current to prevent sudden dip in SOC and to increase battery life. The vehicle control strategy is modeled & simulated using MATLAB™ environment and results for a specific test case are validated with embedded controllers-in-the-loop in a test-bench environment.

Due to recent infrastructural development and emerging competitive automotive markets, there is seen a huge shift in customer’s demand and vehicle drivability pattern in commercial vehicle industry. Now apart from ensuring better vehicle durability and best in class tyre life and fuel mileage, a vehicle manufacturer also has to focus on other key attributes like driver’s safety and ride comfort. Thus, for ensuring enhanced drivability, key parameters for ensuring better vehicle handling includes optimization of bump steer and brake steer. Both bump steer and brake steer are vehicle’s undesirable phenomenon where a driver is forced to constantly make steering wheel correction in order to safely maneuver the vehicle in the desired path.

Engine mounts and mounting brackets play a critical role in determining NVH performance of a vehicle. A lot of work has been done in the area of virtual simulation using FE models to study engine mounting system performance and its impact on vehicle level performance. An overall approach towards engine mounting system validation at vehicle level is also very critical to validate simulation results in a prototype based on which further refinement work will be carried. In this paper a detailed procedure for engine mount and mounting bracket physical validation at vehicle level is presented. Various tests to be performed at vehicle level to quantify engine mount and mounting bracket performance parameters is discussed in detail along with measurement procedures and techniques. Test results are interpreted and its impact on overall performance is also explained. These test results will help design engineers to further improve engineering parameters of mounts and mounting brackets.

There have always been different approaches when it comes to ‘Bus body architecture’. The design approach has gone through different phases namely, chassis based, semi integral, integral and monocoque. Equally varied is the choice of material for bus super structure. The predominantly used ones are - mild steel with galvanization, stainless steel (SS) and aluminum. This paper discusses the rationale behind choosing stainless steel for the complete bus structure. With rapid development in infrastructure and public mass transit system, it has become imperative to have a robust structure for buses that is durable and crash worthy. Among the family of stainless steels, ferritic stainless steel exhibits excellent mechanical properties with corrosion resistance and better strength to weight ratio compared to the galvanized mild steel.

In mining tippers, rear suspension plays a major role in defining vehicles ride and handling characteristics, stability and load carrying capacity. Bogie type of suspension is well suited for these applications. Bogie suspension mainly consists of bogie bracket, leaf springs and radius rods. Nonlinear static analysis is performed for a bogie bracket assembly considering bolt pretension and contacts to evaluate the static strength of bogie bracket. Since bogie bracket is connected to frame with several bolts, a sensitivity analysis is carried out to study the effect of bolt loosing on bogie bracket. The surface contact interaction (stick-slip) behavior between frame and bogie suspension mounting bracket is also studied. Good correlation is achieved with testing results.

CAE based methodologies for structural analysis has improved considerably and is now commonly used for product development. This methodology can also be used effectively for certification of products against safety standards requiring structural performance. Use of CAE can address the issue of certifying a large number of product variants without the need of expensive and destructive physical tests. The probability and variation in rollover accident varies with different bus application. This paper discuss on the major change in the requirement between flat rollover with the convention rollover over 800mm ditch. It also discusses on the severity of rollover in both rollover scenarios for intercity applications using simulation techniques.

Automotive industry is progressively embracing newer technology for buses, as they are increasingly becoming the backbone of urban transportation. Buses are generally classified based on floor heights, lengths, seating capacity and applications besides lot of other parameters. Generally low floor / low entry buses are used for city transportation, while high floor / high deck buses are used for inter urban and intercity transportation. Yet in a few developing and underdeveloped geographies across the globe, high deck or the semi low floor buses are still used for city/urban transportation. There could be a lot of reasons like infrastructure limitations, the cost of ownership or in some cases even the topology of these geographies could be unfriendly towards low floor buses and low ground clearances. Varying customer requirements, applications and environmental factors necessitates a broad range of offerings from any bus OEM.

Natural gas (CNG) vehicles have been introduced in many parts of world including India, Europe and United States and achieved tremendous success in addressing the energy security and pollution challenges. This paper describes in detail the safety requirements for CNG vehicles in India, Europe and United States. Various safety and design requirements for CNG fuel system components such as gas cylinders, cylinder valves, fuel lines, filling connection, pressure regulator, gas-air mixer, electrical systems, are explained. The safety requirements described in ISO standards, UN-ECE standards, USA FMVSS, NFPA standards and Indian Standards are compared and discussed in detail. It also specifies the procedure for commissioning and installation of CNG vehicles. Further, it is concluded that all these international standards for CNG vehicles have adequate provisions with regard to impact protection, passenger safety and fire safety.

‘To achieve more from less’ has been the oft-quoted phrase in auto industry for quite some time. This philosophy has many analogies like fuel efficiency, modularity, weight reduction, alternative fuels etc. Of these ‘modularity’ is seen as an effective tool, especially for automotive OEMs catering to a wide portfolio of similar products. This paper discusses the implications of modularization on a passenger bus OEM, by taking the ‘bus super structure’ as a test case. The modularized bus structure is compared with the conventional structure for design strength, safety, weight and more importantly manufacturing flexibility. The challenges faced in each of these aspects are discussed. From the study it was understood that the task of manufacturing body modules and interfaces is complex and it calls for a complete revamp of existing fixtures, material handling equipment and even the prescribed tolerances.

Overloading is not only a problem for larger goods vehicles, it is equally a problem for smaller vehicles, such as vans, cars and passenger carrying vehicles. Reports indicate that nearly 70% of all traffic on national highways comprise of cargo vehicles while 22% of cargo vehicles are involved in road accidents. Overloading increases the risk of traffic accidents and causes excessive wear and damage to roads, bridges, pavements etc. This paper specifies in detail the existing Indian Legislation on Overloading, different methods of monitoring, Vehicle Overload Control in other countries and India recommendations to curb Overloading of vehicles.

Buses have been main means of mass transport in organized as well as unorganized sectors in India. Though the art and science of Chassis Designing had been practiced and matured by all Indian OEMs, Body design had long not been accorded high priority by them. Till 1989, there was no comprehensive set of rules enforced. Bus designs were developed with scant regard for safety and emission. OEMs sold their products in the form of drive away chassis and the Body Design & Body Building was largely left to Body Builders, many of whom employed poor design, build and quality control practices. Spurious materials, parts, non-uniform construction resulted in number of accidents and many of them were fatal. Central Motor Vehicle Rules (CMVR) kicked-in 1st July 1989. With roll out of CMVR, various safety related features like entry/exit door, emergency exits, window frames, their locations, dimensions and designs were defined.

Oil strainer is used in engine oil sump, which prevents dirt, scale and other particle from clogging downstream orifice. In this paper, dynamic analysis was carried out using FEA tool. As a part of dynamic analysis, constrained modal analysis and frequency response (steady state dynamics) analysis was done. Frequency response analysis was done for different engine exciting frequency at different service load (vibration amplitude). Modal superposition method is used for doing frequency response analysis and load is applied as base excitation. The natural frequency from modal analysis and stress response from frequency response analysis is well correlated with test results. Based on achieved good correlation with test, several design modification could be carried out in CAE before finalizing the final design.

The application of virtual simulations of crash has become an integral part of the vehicle development process. Virtual simulation offers opportunities to reduce development time and the number of physical prototypes consumed for design verification and validation. With the continuously increase of new accident and regulatory scenarios the dependency to virtual simulation and validation is becoming an inseparable factor in product development. This paper presents simulations that are performed to verify various safety aspects to ensure crashworthiness of the truck cabin. The cabin structure was evaluated for various load cases as per ECER 29 rev 2.0 safety regulation [1]. The FE model and simulation methodology was validated through physical testing and correlated for frontal impact test and roof strength test as per AIS 029/ECE-R 29 rev 2.0 [2]. Paper also discuss on the issue faced in correlation of test vs. Virtual validation using explicit solver.

The Chassis Dynamo-meter system provides a means of testing vehicle in place of driving them on the test track or highway. The machine simulates road conditions in speed, torque or road load control modes, allowing the vehicle to experience the same forces as it would be on the test track or highway. Chassis dynamo-meter with its 24 x 7 capabilities can perform several value-added tests to assess vehicle performance while operating under load in short period of time and with other intangible benefits such as well-timed product launch, reduced breakdown time and faster failure resolution, Dynamo-meter is worthy of an investment. However, the scale of investment and constraints in required infrastructure limits the number of dynamo-meters in a R&D center of Original Equipment Manufacturers.

Vehicle light-weighting of late has gained a lot of importance across the automotive industry. With the developed nations like the U.S. setting stringent fuel economy targets of 54.5 mpg by 2025, the car industry's R&D is taking light weighting to a whole new level, besides improving engine efficiency. The commercial vehicles on the other hand are also gradually catching up when it comes to using alternate material for weight reduction. This paper will discuss light-weighting in the context of buses though. For a typical bus, the contribution of shell structure weight in the bus body weight is more than 40%. This qualifies as the area with a huge potential for weight saving. On the other hand the shell structure forms the base skeleton of the bus body providing it with adequate strength and stiffness for meeting both functional (bending & torsional stiffness) and passive safety requirements (rollover compliance).

The commercial vehicle industry is evolving faster with the rise in multifarious aspects deciding a company's progress. In the current scenario, vehicle performance and its reliability in the areas of payload, fuel economy, etc. play vital roles in determining its sustenance in the industry, in addition to reducing driver fatigue and improving comfort levels. Test quality and time is the key to assure and affirm, smooth and quick launch of the product into the market. This paper details on the design of Multi-Axis road data simulator which entails realistic loads onto the components for capturing meaningful information on behavior of the product and recreate the field failure modes. The design was conceptualized keeping in mind both cost (for initial installation and running cost) and time for testing without loss in the convergence factor.

This paper describes a methodology for design and development of On-Board Diagnostic system (OBD) with an objective to improve current reliability process in order to ensure design & quality of the new system as per requirement of commercial vehicle technology. OBD is a system that detects failures which adversely affect emissions and illuminates a MIL (Malfunction Indicator Lamp) to inform the driver of a fault which may lead to increase in emissions. OBD provides standard and unrestricted access for diagnosis and repair. Below given Figure 1 shows the working principle of OBD system. The exhaust emission of a vehicle will be controlled primarily by Engine Control Unit (ECU) and Exhaust Gas After Treatment Control (EGAS CU). These two control units determine the combined operating strategies of the engine and after treatment device. Figure 1 Modern Control Architecture for OBD System in Commercial vehicle [1]

Design decisions based on the virtual simulations leads to reduced number of prototype testing. Demonstrated correlation between the computer simulations and experimental test results is vital for designers to confidently take simulation driven design decisions. For the virtual design evaluation of durability, ride, handling and NVH performance, demonstration of correlation of structural dynamic characteristics is critical. Modal correlation between CAE and physical testing validates the stiffness and mass distribution used in the FE model by correlating mode shape and mode frequency in the desired frequency range. The objective of this study is to arrive at a method for establishing modal correlation between CAE and experimental test for a bare frame and thereby enabling evaluation of design iterations in virtual environment to achieve modal targets.

Diesel engine pollutants include Oxides of Nitrogen (NOx) and Particulate Matter (PM) which are traditionally known for their trade-off characteristics. It’s been a challenge to reduce both pollutants at the source simultaneously, except by efforts through low temperature combustion concepts. NOx formation is dependent on the combustion temperature and thus the in-cylinder reduction of NOx formation remains of utmost importance. In this regard, water injection into the intake of a heavy-duty diesel engine to reduce peak combustion temperature and thereby reducing NOx is found to be a promising technology. Current work involves the use of 1-D thermodynamic simulation using AVL BOOST for modeling the engine performance with water injection. Mixing Controlled Combustion (MCC) model was used which can model the emissions. Initially, the model validation without the water injector was carried out with experimental data.

In view of the stringent emission norms laid out by government of India, BSVI Engines are with additional heat rejection requirements with limited packaging space for Cooling system. An appropriate Radiator, Charge Air Cooler and Fan is decided within the available packaging space based on the Engine heat rejection needs. In this paper an approach is defined to arrive at a Cooling system architecture which is very compact in design and packaged between the Engine and Front member in a limited space. Modelling is done in Thermal simulation software KULI. Good correlation is achieved between simulation to test results.