Engineering topics

Lapins, M.

Publications and source records attributed to Lapins, M..

5 records

NASA NTRS1983

Control definition study for advanced vehicles

The low speed, high angle of attack flight mechanics of an advanced, canard-configured, supersonic tactical aircraft designed with moderate longitudinal relaxed static stability (Static Margin, SM = 16% C sub W at M = 0.4) was investigated. Control laws were developed for the longitudinal axis (""G'' or maneuver and angle of attack command systems) and for the lateral/directional axes. The performance of these control laws was examined in engineering simulation. A canard deflection/rate requirement study was performed as part of the ""G'' command law evaluation at low angles of attack. Simulated coupled maneuvers revealed the need for command limiters in all three aircraft axes to prevent departure from controlled flight. When modified with command/maneuver limiters, the control laws were shown to be adequate to prevent aircraft departure during aggressive air combat maneuvering.

Lapins, M.↗

NASA NTRS1982

Piloted simulator evaluation of a relaxed static stability fighter at high angle-of-attack

A piloted simulator evaluation of the stability and control characteristics of a relaxed static stability fighter aircraft was conducted using a differential maneuvering simulator. The primary purpose of the simulation was to evaluate the effectiveness of the limiters in preventing departure from controlled flight. The simulation was conducted in two phases, the first consisting of open-loop point stability evaluations over a range of subsonic flight conditions, the second concentrating on closed-loop tracking of a preprogrammed target in low speed, high angle-of-attack air combat maneuvering. The command limiters were effective in preventing departure from controlled flight while permitting competent levels of sustained maneuvering. Parametric variations during the study included the effects of pitch control power and wing-body static margin. Stability and control issues were clearly shown to impact the configuration design.

Lapins, M.↗

NASA NTRS1982

Control law development for a close-coupled canard, relaxed static stability fighter

The performance benefits to be gained from relaxed static stability (RSS) are illustrated for M = 0.9 and M = 2.0 flight conditions. The longitudinal, directional, and lateral control system structure is developed. The effect of static margin, bandwidth, and canard-wing interaction on canard rate requirements is analyzed. Control and maneuver limiter functions are developed and implemented about all three axes; simulation results strikingly demonstrate the concomitant improvement in energy management and improved resistance to departure and spin.

Klein, R. W.↗

NASA NTRS1975

Application of active control technology to aircraft ride smoothing

Prototype Ride Smoothing System (RSSs) were synthesized for flight testing aboard the National Aeronautics and Space Administration General Purpose Airborne Simulator (GPAS). The systems were designed to meet comprehensive criteria including passenger comfort and aircraft handling qualities considerations. System performance estimates based on analytic expressions were compared to estimates derived from digital calculations. The effect of RSSs on pilot workload during ILS approach in turbulence was examined in a fixed-base simulator. A limited number of flights were conducted to verify predicted RSS performance. Results of these experiments indicate that RSSs reduce pilot workload and increase passenger comfort while maintaining handling qualities.

Jacobson, I. D.↗

NASA NTRS1975

Application of active controls technology to aircraft bide smoothing systems

A critical review of past efforts in the design and testing of ride smoothing and gust alleviation systems is presented. Design trade offs involving sensor types, choice of feedback loops, human comfort, and aircraft handling-qualities criteria are discussed. Synthesis of a system designed to employ direct-lift and side-force producing surfaces is reported. Two STOL aircraft and an executive transport are considered. Theoretically predicted system performance is compared with hybrid simulation and flight test data. Pilot opinion rating, pilot workload, and passenger comfort rating data for the basic and augmented aircraft are included.

Lapins, M.↗