Defence Research and Development Laboratory

About: Defence Research and Development Laboratory is a facility organization based out in Hyderabad, India. It is known for research contribution in the topics: Turbulence & Mach number. The organization has 404 authors who have published 420 publications receiving 4183 citations. The organization is also known as: DRDL.

Target hit interceptor mid-course guidance scheme for ballistic missile interception

Abstract: A Mid-course guidance algorithm has been developed for an exo-atmospheric interceptor to neutralize an incoming high speed ballistic Target. The guidance scheme positions the interceptor ahead of the target so that the velocity vectors of the target and interceptors are in the same direction. As the interceptors used in ballistic missile defence have a lower velocity than the incoming target, the target approaches the interceptor. The guidance scheme reduces the closing velocity compared to a head on approach thereby increasing the homing time for a given terminal sensor detection range. The guidance law is validated through numerical simulation.

Quantitative Assessment of the Condensed Phase Heats of Reaction in a Double Base Propellant

Abstract: Heat of decomposition of the double base propellant has been calculated from the knowledge of the composition and decomposition enthalpy of the ingredients. This was compared with the experimentally observed value of the propellant decomposition which suggested that condensed phase contribution is very marginal (one twentieth of the total calorimetric value) in double base propellants unlike composite solid propellants where condensed phase contribution is as high as one third. The condensed-phase in double base propellant was attributed to the nitration of the 2n-diphenylamine stabilizer in the propellant matrix.

Design, Development and Performance Evaluation of Automated Relay Controller for Solenoid Valve Operation During Static Test of Rocket Motors

Abstract: This paper presents the design and development of an automated relay controller for pulse mode operation of solenoid valves for switching on / off the propellant flow to the combustion chamber of a thruster during static test. This paper enumerates the design of multi-channel solenoid valve controller using electro-mechanical relays operated through microcontroller. Two application software have been developed for automation purpose - one for simultaneous operation of multiple solenoid valves, as per required pulse sequence, developed in embedded C language and the other for configuration of the system, developed in MATLAB with a GUI. The performance of the designed system has been evaluated through various tests carried out in lab, field and during static tests.

Euler angle error computation and thrust vector control scheme for initial turning phase of a vertical launch surface to air missile

Abstract: A vertical launch missile requires to be turned towards the Predicted Interception Point (PIP) with the target within few seconds from the launch. The autopilot used for the same requires the error in Euler Angles between the missile and the target to be supplied, which is generally computed using Error Quaternions approach [1]. For some kinds of engagement scenarios, say a Near Boundary Low Altitude target, the turn angle required in the pitch plane during the initial phase can become more than 90 degrees. In such cases, the conventional 3-2-1 frame transformation method fails to compute the Euler Angle errors correctly. As an alternative approach the Euler Angle error computation using 2-3-1 frame transformation is proposed in this paper. After computing the Euler Angle Errors, the desired turning is achieved by Thrust Vector Control [2] using jet vanes or thrusters. The initial turning using Aerodynamic control is not desirable because of low dynamic pressure, where as the usage of jet vanes brings more hardware complications for small tactical missiles. The possibility of using thrusters for initial turning phase in a short range tactical missile is studied in this paper with the help of simulation results.