Search Results

Recently quietness has become an important quality parameter for automotive vehicles and as a result various improvements have been brought to reduce noise at system and vehicle level. Due to stringent noise emission norms on automotive vehicles and increasing desire of quieter in-cab performance by users, reduction of air intake noise tends to be an area of explanation. Air intake noise, which was relatively considered as a minor source of noise in the past, is now gaining importance. To reduce air intake noise basically resonator and expansion chamber are used on automotive vehicles. Resonators are widely used for noise reduction of intake and exhaust systems, but due to increased number of components, its associated cost; complexity of the system increases. The next option that is an expansion chamber prevents the formation of large amplitude standing waves and dissipates sound energy, however use of such a device reduces engine torque at narrow range of engine speeds.

Reliability has been a complicated domain of vehicle engineering, basically due to the quantum of the authentic data required, and variability of parameters that make real contributions to the subject. Reliability of a vehicle in very generic terms, is not only its functional worthiness and consistency, but also its probability to perform satisfactorily within the intended design life for a particular production batch, application domain, operation duty and customer use. Commercial vehicle industry is driven by returns that a vehicle gives, on the investments made, which depend on parameters like minimum turnaround time, lesser breakdowns, optimized maintenance interval and cost of operation etc. Severe operating conditions, regular customer abuse and higher expectations from products (as expected by Indian customer-base) demand a need to deliver more robust and reliable products.

In today's world with a dynamic market and varying customer expectations, it becomes inevitable that we find means of recognizing customer needs with all dimensions and instill them as inherent specifications of a product. Automobiles no way fall away from these intangible demands of the changing world, as personal conveyance (car/motorcycle/scooter) nowadays is more of a basic need. It becomes more of challenge to automotive manufacturers, to offer continuously improving quality products, at competitive prices to be in business. It's very important that as automotive designers we recognize quality in its totality and establish a predictive methodology to inculcate quality into the design at early stages of vehicle development.

The primary factors influencing vehicle's dynamic behavior are the vehicle hard point definition, driver behavior and road inputs. The more the latter two are random and incorrigible in nature, the former one is quantifiable and can be controlled from designer's standpoint. In this paper, we have made an attempt to set targets to the vehicle hard point definition and thereby to optimize the vehicle for better ride behavior. This approach hence helped to converge to vehicle specifications set fundamentally designed to respond to random operating conditions and driving behavior intelligently. The work also involves study of various methodologies to predict roll, pitch, bounce and dive behaviors on a typical commercial passenger vehicle and is concluded by a sensitivity analysis to understand significance of these hard points on vehicle's real time behavior.