Frequency response analysis of hybrid systems

Current design methods for digital control systems to be operated in a continuous environment do not always result in the most efficient use of digital computing hardware. To improve this situation, a dedicated frequency response analysis method was developed for hybrid systems. For practical use of the method, it has been expanded to an...

Design and experimental verification of a calculation method for frequency response analysis of digital control systems in a continuous environment

A method has been developed to analyze the transfer characteristics of combined discrete (digital) and continuous (analog) systems. Such combinations are called hybrid systems. In particular digital controllers, operating in a continuous environment have been considered. An essential element of a hybrid system is a sampler, which is modelled in...

Bepaling van de eigenwaarden, toegepast op symmetrische scheepsbewegingen

Wind shear on the approach: An investigation on the infuence of a tower measured wind environment on the symmetric motions of a simulated aircraft in an automatic approach

Measured wind profiles from the Royal Netherlands Meteorological Institute 200 m meteorological tower at Cabauw have been used to estimate wind shear effects on the symmetric motions of an approaching aircraft. Wind profiles as well as an automatically approaching DC-9 aircraft have been simulated on an electronic analog computer. The study...

Investigation on a passenger ride-comfort improvement system with limited control surface actuator performance for a flexible aircraft

For the low wing-loading aircraft, considered in this investigation, vertical acceleration appeared to be an important factor concerning passenger comfort. To reduce vertical motions, a ride-comfort improvement system was introduced. Determination of parameters of the system, like gains and allowable performance limitations, required analog...

Preliminary investigation on the ride-comfort improvement of a low wing-loading transport, including a limited comfort criteria study

A limited investigation on the possihility of improving the passenger ride comfort of a low wing-loading transport has heen descrihed in the present report. A literature study on comfort criteria, included in this report, did show that passengers attach much importance to vertical and lateral motion. It appeared that for the aircraft concerned...

Simulation of the automatic approach of a twin-engined jet transport

In order to obtain insight in the accuracy of automatic approaches, the symmetric motions of an aircraft, stabilized by autopilot and autothrottle, are simulated on an electronic analog computer. The aircraft tracks an I.L.S. glide path, being disturbed by I.L.S. beam bends, atmospheric turbulence and wind shear. The deviations of the aircraft...

Mathematical model of external disturbances acting on an aircraft during an its approach and landing