A gravity protective system for pilots including a pressurized suit and a control system therefor for regulating the pressure in the suit in response to variations in acceleration along the thoracic axis of the pilot. Signals indicative of acceleration along the vertical axis of the aircraft and cosine function of the tilt angle of the pilot's seat are combined with a derivative function of their product to produce a control signal for regulating the air pressure within the suit. A threshold control limits regulation to acceleration above a predetermined level, and a feedback circuit from the suit ensures rapid response without oscillation.

An improved G-seat system for providing kinesthetic cues to the operator of a vehicle simulator in which the motion sensations associated with the "G" forces are simulated by the motion of a single seat plate (62) having a pair of passive thigh ramps (78) mounted thereon and the variation in the degree of inflation of thin bladders (82A,B) which overlie the seat plate. Raised surfaces (80) may be provided on the plate beneath the ischial tuberosity region of the operator to increase the dynamic range of perceived g-loading effects. A backrest plate (92) may be provided for motion in conjunction with the seat plate and a thin bladder (128) may likewise be provided theron. Driven radial elements (108,110) may then be positioned on the lower part of the backrest plate to augment pressure cues at selected areas of the operator's back.

A vehicular seat assembly (10) includes a pair of bolsters (18, 20) located on either side of the seat back (14). Each of the bolsters (18, 20) includes a primary adjustor (22) which moves the bolster (18, 20) to a position found to be comfortable by the occupant of the seat (10). Each of the bolsters (18, 20) further include a secondary adjustor (26) disposed adjacent the first adjustor (22). The two secondary adjustors (26) operate independently of each other and deploy when the seat assembly (10) senses a predetermined level of lateral acceleration forces (36 or 38). An accelerometer (34) senses the lateral acceleration (36, 38) and a control circuit (32) sends a signal to an activator (40) to deploy the one of the two secondary adjustors (26).

A system for counteracting the effect of helicopter vibrations on a seat in the helicopter which seat includes a plurality of controllable air cells includes a means for varying the pressure of the cells and transducer means for sensing cell pressure and vibrations and for providing electrical signals representative thereof. Control means provide signals for controlling the means for varying and processing means process the electrical signals and provide driving signals for driving the control means. A processing means converts the electrical signals to provide driving signals which drive the control means to control the means for varying so as to counteract the changes in pressure in the air cells due to vibrations to eliminate or reduce the changes in pressure with this system, the pilot is isolated from the helicopter compared with prior art systems where the seat is isolated from the helicopter.

An anti-G suit simulation system and especially pertains to an arrangement or system for simulating realistic acceleration conditions which are normally encountered during strenuous maneuvers carried out by pilots operating high-performance aircraft, such as jet fighter aircraft. More particularly, there is disclosed an anti-G simulation system wherein aircraft simulator pilots are exposed to physical conditions which rapidly and faithfully simulate and compensate for changes in high-intensity accelerations and gravitational effects or so-called G-conditions which are ordinarily encountered by the pilots of high-performance aircraft during the execution of aircraft maneuvers. Provided is a novel high/low-pressure vacuum system in which a series of solenoid valves are controllably connected to a source of high-pressure operating air and respectively, in a selective mode to high-pressure and low-pressure pumps which are adapted to be actuated responsive to signals received from a simulator computer so as to controllably evacuate the anti-G suit in conformance with specific reductions in G-forces simulated by the system.