Showing papers by "Defence Research and Development Laboratory published in 2002"

Theory and application of 3‐D LSKUM based on entropy variables

Abstract: This paper describes the theory and application of a grid-free kinetic upwind scheme known as LSKUM.The basic principle in LSKUM is the determination of derivatives occurring in the conservation laws using the least squares method. The grid-free nature of the scheme is obtained because the least squares method can be used on an arbitrary distribution of nodes, i.e. the nodes need not form a structured/unstructured grid.

Performance analysis of nominal scheme and decoupling loop scheme for rf seeker

Abstract: Airborne seeker has to perform the role of target tracking with low pointing error as well as good disturbance rejection particularly with respect to flight vehicle motion. Although seeker with high stabilization loop gain (Ksl) performs the role of good disturbance rejection, it inherently increases the cost, weight and power requirements of the seeker. Good disturbance rejection is essential as disturbances in the form of high magnitude body rates has to be attenuated sufficiently so that its effect is as low as possible in the guidance signals to be tapped from the seeker. A special configuration known as decoupling loop scheme is sometimes employed to annul the effect of body rate disturbances in the synthesized LOS rate signal which is generally tapped from the seeker for guidance. Decoupling loop approach works well with IR / IIR seeker based homing guidance, but its effectiveness is not yet explored when a parasitic path exists in seeker in the form of radome aberration error as is the case in all RF seekers. The present paper deals with performance analysis of decoupling loop scheme and nominal scheme from the point of view of inner guidance loop (fig.1 and fig.2) stability and body rate decoupling from synthesized sight line rate in the presence of radome slope error. Generic formula of body rate decoupling from guidance signal; i.e synthesized sight line rate is derived in case of RF seeker for both nominal and decoupling loop scheme in the presence of radome slope error. The basic difference of both the schemes affecting seeker and guidance performance is brought out in a generic manner for different types of flight vehicles with varying response characteristics and different engagement situations. The stability of inner guidance loop of the two schemes, characterized by different realistic stabilization loop gains for different types of (fast or slow) flight vehicles, different engagement situations and guidance loop response time achievable in both the schemes are compared. The reported studies show that decoupling

Integrated Process for Smooth Transition from Development to Production of Weapon Systems

Abstract: Production of weapon systems has proven to be as difficult as their development. The transition from development to production encompasses innumerable efforts to take a weapon system from laboratory into full-scale production. These efforts may span the development and production phases and constitute a major determinant of a weapon system's production costs. Besides, Indian manufacturers/production units, who seek know-how, generally go to foreign manufacturers and obtain complete production know-how. Obviously, they expect same kind of technological support, which are the preserves of the manufacturers'. An attempt has been made for the first time by Defence Research & Development Laboratory (DRDL), Hyderabad for a technology transfer of highly sophisticated missiles to production agency. Experiences show that the technology receiver (i.e. production agency) should have a willingness to receive the technology and the technology donor should understand the culture of technology receiver and recode/restructure the technological information to fit into the technology receiver's domain. Production planning and preparations were conducted throughout the development phase to identify production requirements and to resolve the difficulties before production begins to achieve quality products. A unique technology transfer mechanism has been evolved and implemented successfully for one of the weapon systems developed by DRDL, Hyderabad. Production agencies have demonstrated their capability to produce subsystems of a weapon system of desired quality within the time schedule and cost by the time the weapon system performance was demonstrated to the users. Also, the deliveries of systems of development hardware continued into the production phase and production deliveries began with no line interruption.

Evaluation of Conducive Environment for Implementation of Quality Management System in an Organisation

Abstract: The ISO 9000 quality management system (QMS) is a philosophy. It is a consistent and logical approach, which if implemented and practiced in day-to-day activities, with total support from senior management, can lead to doing things right, first time-every time. Many organisations adopt ISO 9000 system as a milestone in their quest for quality management programme. Effectiveness of a system depends on the attitude of employees who are responsible for its implementation. Therefore, it is essential to know the prevailing environment in an organisation. To measure the attitude of employees, a survey through a wel1-designed questionnaire can be used as an effective tool. The items of questionnaire are framed on the basis of requirements of QMS. Attitude of employees is measured on a five-point scale, for each answer. Agreement or disagreement (positive or negative) directly measures the attitude of an employee on the said aspect Data analysis is carried out for establishing the validity of individual score to the total score of items across, using product moment correlation formula. Based on analysis of data, a comprehensive programme can be worked out for correcting the deficiencies observed through the attitude survey. This can also be used as a base for measuring the improvement of QMS in an organisation.