Body displacement measured during sustained Gz, -Gz and or -Gy acceleration using a stereoscopic photographic system

摘要

Pilot performance may be adversely affected by G induced body displacement. Controls may be difficult to reach and activate. The use of a head up display may be rendered ineffective by excessive head movement. Also, measurement of body displacement can be useful in evaluating restraint systems. A technique has been devised to quantify body displacement during acceleration studies conducted on the Dynamic Environment Simulator (DES), a three axis centrifuge. A stereoscopic photographic system consisting of two motorized 35 mm SLR cameras, a microprocessor controller, and displays were used. Reference marks defining the DES can in 3 dimensions (3-D) and targets on the subject are recorded photographically. The film strips were then processed on an x-y plotter to digitize the target information. From these data, calculations were performed to compute the 3-D coordinates of the points of interest. Data collected when using the stereoscopic photographic systems are presented on eye and shoulder displacements during various acceleration and restraint conditions. Eye displacements of 3.95 cm at 4.0 Gz, 4.79 cm at -1.0 Gz, and 10.16 cm at 2 Gy are reported. Improving the restraint system by adding lateral shoulder supports reduced the eye displacement at 2 Gy to 3.96 cm (61 percent). The average lateral restraining force exerted on the shoulder pads at 2 Gy was 55.8 Kg (123 lbs).