The economical optical sensor for measurements of drone coordinates in three-dimensional space is presented. Now drones use digital cameras to perform accurate taking off, landing or dumping of goods. Stabilized digital cameras with electronics for image compression and transmission via high speed wireless channel make drones expensive, reduce their weight payload and battery charge. The proposed optical sensor guarantees the coordinate measurements with ten centimeter accuracy in a volume with dimensions of several meters. The illumination part of this sensor is installed round a landing pad or a goods delivery pad. It forms a set of low-energy optical beams of definite shapes. Each beam transmits a digital code that characterizes its location relatively the pad. The receiving part of this sensor is a set of miniature photodetector units that are fixed under a drone. The proposed technique of the beam code comparison helps to calculate the drone coordinates relatively the pad. As a result, this sensor closes the gap between the accuracy of the Global Positioning System and the centimeter accuracy necessary for accurate drone taking off or landing without usage of a digital camera. The paper describes the sensor design and the experimental testing of this optical sensor. The advantages and possible applications of this sensor are also discussed.
The paper describes the design procedure that allows identification of the optimal parameters of the light source based on optically connected integrating spheres. This source provides a high dynamic range of output radiance with high uniformity of radiance distribution throughout an output aperture. The procedure deals with relative parameters of apertures of primary and secondary integrating spheres, aperture areas, density of lamps and etc. It makes possible calculation of the set of optimal parameters that guarantees the maximal output radiance with high uniformity of its distribution through an output aperture. The paper demonstrates the application of this procedure in the light source design.