9 research outputs found
Pilot's manual for automated 4D guidance system
Operational procedures and modes of an experimental 4D guidance system are described from the pilot's point of view. The system consists of the experimental avionics equipment referred to as STOLAND and a specially developed software package for the STOLAND digital computer. A capture mode of the system provides arrival time control and automatic tracking of the 4D flight path from any feasible initial aircraft state to any waypoint. Precise arrival time at a waypoint is achieved by means of speed control or, if large delays are required, by path stretching. Continuous recomputation and display of the capture flight path prior to engaging the system permits the pilot to determine the exact moment for terminating a holding or path stretching maneuver in order to achieve a specified arrival time
Four-dimensional guidance algorithms for aircraft in an air traffic control environment
Theoretical development and computer implementation of three guidance algorithms are presented. From a small set of input parameters the algorithms generate the ground track, altitude profile, and speed profile required to implement an experimental 4-D guidance system. Given a sequence of waypoints that define a nominal flight path, the first algorithm generates a realistic, flyable ground track consisting of a sequence of straight line segments and circular arcs. Each circular turn is constrained by the minimum turning radius of the aircraft. The ground track and the specified waypoint altitudes are used as inputs to the second algorithm which generates the altitude profile. The altitude profile consists of piecewise constant flight path angle segments, each segment lying within specified upper and lower bounds. The third algorithm generates a feasible speed profile subject to constraints on the rate of change in speed, permissible speed ranges, and effects of wind. Flight path parameters are then combined into a chronological sequence to form the 4-D guidance vectors. These vectors can be used to drive the autopilot/autothrottle of the aircraft so that a 4-D flight path could be tracked completely automatically; or these vectors may be used to drive the flight director and other cockpit displays, thereby enabling the pilot to track a 4-D flight path manually
Optimal Synthesis of the ZermeloâMarkovâDubins Problem in a Constant Drift Field
The original publication is available at www.springerlink.com.DOI: 10.1007/s10957-012-0128-0We consider the optimal synthesis of the ZermeloâMarkovâDubins problem, that is, the problem of steering a vehicle with the kinematics of the IsaacsâDubins car in minimum time in
the presence of a drift field. By using standard optimal control tools, we characterize the family
of control sequences that are sufficient for complete controllability and necessary for optimality
for the special case of a constant field. Furthermore, we present a semi-analytic scheme for the characterization of a (nearly) optimal synthesis of the minimum-time problem. Finally, we
establish a direct correspondence between the optimal syntheses of the MarkovâDubins and the
ZermeloâMarkovâDubins problems by means of a discontinuous
mapping
Sample preparation focusing on plant omics
Because of strong impact of omics in many fields, and the complexity of the samples when focusing on areas such as genomics, (metallo)proteomics, metabolomics, among others, it is easy to rationalize the great importance that sample preparation has for achieving reliable results, mainly considering plant science. Then, this chapter points out applications of the sample preparation focusing on such areas, and a diversity of strategies, techniques, and procedures is highlighted and commented1073161185CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESPThe authors gratefully acknowledge the financial support of Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP), the Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq), and Financiadora de Estudos e Projetos (FINEP