Direct Method Based Control System for an Autonomous Quadrotor

This paper proposes a real time control algorithm for autonomous operation of a quadrotor unmanned air vehicle. The quadrotor is a small agile vehicle, which as well as being a excellent test bed for advanced control techniques could also be suitable for internal surveillance, search and rescue and remote inspection. The proposed control scheme incorporates two key aspects of autonomy; trajectory planning and trajectory following. Using the differentially-flat dynamics property of the system, the trajectory optimization is posed as a non-linear constrained optimization within the output space in the virtual domain, not explicitly related to the time domain. A suitable parameterization using a virtual argument as opposed to time is applied, which ensures initial and terminal constraint satisfaction. The speed profile is optimized independently, followed by the mapping to the time domain achieved using a speed factor. Trajectory following is achieved with a standard multi-variable control technique and a digital switch is used to re-optimize the reference trajectory in the event of infeasibility or mission change. The paper includes simulations using a full dynamic model of the quadrotor demonstrating the suitability of the proposed control scheme.     

Dot Size Thermal Objects Detection in Atmosphere of Infrared Range

The article deals with the experimental studies of atmosphere indistinct radiation structure. The information extraction background of dot size thermal object presence in atmosphere is reasonable. Indistinct generalization of experimental study regularities technique of space-time irregularity radiation structure in infrared wave range is offered. The approach to dot size thermal object detection in atmosphere is proved with a help of threshold method in the thermodynamic and turbulent process conditions, based on the indistinct statement return task solution.     

A method of compensating atmospheric background radiation

A method of compensating the atmospheric background and a method of detecting thermal objects on the atmospheric background using infrared thermal direction finders with a wide field of view is described. An algorithm of a two-dimensional spatial filter is developed, which can be realized as software in the video processor of the thermal direction finder. The algorithm enables the process of detecting air targets to be automated and enables their video images to be displayed on the monitor of the monitoring device in binary form.     

Coherent and incoherent components of a synchrotron radiation spot produced by separate capillaries

We discuss soft-x-ray focusing properties of separate capillaries. It is shown that a nonnegligible fraction of the synchrotron radiation beam transmitted by the capillary is modal. Experimental and theoretical data are discussed to explain the superposition pattern of x rays in the focal plane due to the interference phenomena of electromagnetic radiation propagating through separate capillaries.     

Capacitance-voltage characteristics of p-n structures based on (111)Si doped with erbium and oxygen

Capacitance-voltage characteristics of tunneling diodes fabricated by co-implantation of erbium and oxygen in single-crystal (111)Si wafers have been studied. Anomalous enhancement of the p-n-junction capacitance with increasing reverse bias has been observed at certain temperatures depending on the implantation dose. The rise in capacitance (decrease in the space charge region width) is associated with the formation of deep levels of high density in the band gap of n-layer of the p-n junction and electron emission from these levels in the space charge region with increasing voltage. The obtained results show that the parameters of the defects responsible for the levels depend on the erbium and oxygen implantation doses.