Accession Number : AD0664090

Title :   RESEARCH ON ACTIVE VIBRATION ISOLATION TECHNIQUES FOR AIRCRAFT PILOT PROTECTION.

Descriptive Note : Final rept. Jun 65-Dec 66,

Corporate Author : BARRY WRIGHT CORP WATERTOWN MASS BARRY CONTROLS DIV

Personal Author(s) : Calcaterra,P. C. ; Schubert,D. W.

Report Date : OCT 1967

Pagination or Media Count : 51

Abstract : An investigation was conducted to evaluate the feasibility of protecting pilots from the vertical dynamic excitations experienced during low-altitude, high-speed (LAHS) flight by means of active isolation techniques. Performance specifications for candidate isolation systems were evolved based on definition of the expected dynamic environment, human tolerance levels, and cockpit clearance. Required vibration isolation and maximum relative displacement values were postulated. Analyses of existing isolation techniques indicated that, for the selected dynamic environment typically experienced during LAHS flights in the vertical direction (i.e., combined vibration and sustained acceleration excitations), passive systems cannot provide the required degree of vibration isolation while simultaneously limiting the maximum relative displacement to the desired values. Various active isolation techniques were evaluated. An active hydraulic system was selected, employing acceleration and displacement feedback mechanisms. Analyses were conducted to define the type of compensation and loop gains required to provide the desired isolation, limit the dynamic deflection, and maintain system stability. A laboratory model for experimental research was designed and tested. Test results show that the developed active hydraulic isolation technique provides the vertical isolation and displacement control postulated to be required for pilot protection during LAHS flight. In addition, the system exhibits zero static deflection, and is essentially insensitive to forces applied at the isolated payload, and to human-body resonance coupling effects. (Author)

Descriptors :   (*COCKPITS, *VIBRATION ISOLATORS), PILOTS, ACCELERATION TOLERANCE, HUMAN FACTORS ENGINEERING, HYDRAULIC EQUIPMENT, PROTECTION, VIBRATION, FEASIBILITY STUDIES, LOW ALTITUDE, PERFORMANCE(ENGINEERING), SPECIFICATIONS, AIRSPEED, FEEDBACK, AIRCRAFT SEATS

Subject Categories : Aircraft
      Human Factors Engineering & Man Machine System

Distribution Statement : APPROVED FOR PUBLIC RELEASE