Abstract: A non-contact sensing system for monitoring the position and orientation of a rigid body in space having at least three distinct point light sources mounted on the rigid body. At least two position sensor heads are fixedly mounted within detection range of light from the light sources, each position sensor head having a position sensitive detector. The lights are illuminated one at a time and in sequential arrangement and a processor computes the position in three-dimensional space of an illuminated light source with data provided simultaneously by both position sensitive detectors. The processor means also computes the position of the object in all six degrees of freedom using the three-dimensional positional data of all three light sources.

Abstract: 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.

Abstract: The invention relates to a motion simulator system, for example, a flight simulator system. In accordance with the invention, the system is driven by command signals representing both position and acceleration, and a circuit is provided to process and combine the signals to provide a system command signal. High frequency position command signals, and low frequency acceleration command signals, are eliminated by their drive circuits, and all command signals are varying electrical voltages.