Missile guidance with constrained intercept body angle
A linear quadratic based missile guidance law is presented that imposes a predetermined terminal body angle. Solutions are provided for arbitrary order autopilot dynamics, with explicit analytical expressions given for first-order and zero-lag dynamics. Performance is demonstrated through simulation in a planar interception scenario.
Differentiator-Based Output-Feedback SlidingMode Control for Angle Constrained Midcourse Guidance
A new guidance law with terminal angle constraint is presented for the midcourse guidance of anti-hypersonic missiles, thus to realize a near head-on scenario at the start of terminal phase. The proposed differentiator-based outputfeedback sliding mode guidance law is derived from supertwistbased differentiator and prescribed convergence law for secondorder sliding mode controller. Considering nonlinear dynamics of planar engagement, relative range and its derivative, line-of-sight angle and a guess of maximum target maneuverability is required for the implementation of new guidance law, information can always be available through data link from ground-based or air-based platforms. Fast convergence of line-of-sight angular rate as well as flight path angle can be expected. Simulation results validate the effectiveness of new guidance law against various target maneuvers and also illustrate the superiority when compared to conventional guidance laws.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.