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In this study, the integrated navigation system, consisting of radio and inertial navigation system (INS) altimeters, is presented. INS and the radio altimeter have different benefits and drawbacks. The integration is achieved by using an indirect Kalman filter. Hereby, the error models of the navigators are used by the Kalman filter to estimate vertical channel parameters of the navigation system. In the open loop system, INS is the main source of information, and radio altimeter provides discrete aiding data to support the estimations. At the next step of the study, in case of abrupt faults, the performance of the integrated system is examined. The optimal Kalman filter reacts with abnormal estimates to this situation as expected. To recover such a possible malfunctioning, the robust Kalman filter algorithm is suggested.

IN the days when the top speed of aircraft was of the order of 100 to 150 m.p.h., the designer relied on the pilot's impressions and the pilot in turn relied on being able to jot things down at odd moments on the pad which he had strapped to his knee. This method of flight testing, often known as ‘flying on the seat of the pilot's pants’, had the great disadvantage that the pilot might be preoccupied with one problem which might completely mask other more important, but less apparent, happenings.

This paper aims to reveal the authors’ conceptual and experimental work on an innovative avionics paradigm for small unmanned aerial vehicles (UAVs).

This novel approach stipulates that, rather than being centralized at the autopilot, control of avionics devices is instead distributed among controllers – spread over the airframe span, in response to avionics devices’ natural location requirements. The latter controllers are herein referred to as edge controllers by the first author.

The edge controller manifests increased efficiency in a number of functions, some of which are unburdened from the autopilot. The edge controller establishes a new paradigm of structure and design of small UAVs avionics such that any functionality related to the periphery of the airframe is implemented in the controller.

The research encompasses a workbench prototype testing on a breadboard, as the presented idea is a novel concept. Further, another test has been conducted with four controllers mounted on a quadcopter; results from the vertical attitude sustenance are disclosed herein.

The motivation behind developing this paradigm was the need to position certain avionics devices at different locations on the airframe. Due to their inherent functional requirements, most of these devices have hitherto been placed at the periphery of the aircraft construction.

The current paper describes the novel avionics paradigm, compares it to the standard approach and further reveals two experimental setups with testing results.

A new reducing valve for aircraft high‐pressure missile gas systems, where a high outlet controlled pressure is necessary, has been developed by The Hymatic Engineering Co. Ltd., Redditch, Wores. Known as type PAS 322, the valve has been designed as part of an integral system and the associated valves with it include relief, solenoid and manually‐operated stop valves. The PAS 322 has outlet pressures of 1,000 to 3,000 Ib./sq. in. which can be controlled at any pre‐set figure with flows up to 15 cu. ft./min. of free air. It has an inlet pressure of up to 6,000 lb./sq. in.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the U.S. National Advisory Committee for Aeronautics, and publications of other similar research bodies as issued

This study aims to design an optimized algorithm for low-cost pedestrian navigation system (PNS) to correct the heading drift and altitude error, thus achieving high-precise pedestrian location in both two-dimensional (2-D) and three-dimensional (3-D) space.

A novel heading correction algorithm based on smoothing filter at the terminal of zero velocity interval (ZVI) is proposed in the paper. This algorithm adopts the magnetic sensor to calculate all the heading angles in the ZVI and then applies a smoothing filter to obtain the optimal heading angle. Furthermore, heading correction is executed at the terminal moment of ZVI. Meanwhile, an altitude correction algorithm based on step height constraint is proposed to suppress the altitude channel divergence of strapdown inertial navigation system by using the step height as the measurement of the Kalman filter.

The verification experiments were carried out in 2-D and 3-D space to evaluate the performance of the proposed pedestrian navigation algorithm. The results show that the heading drift and altitude error were well corrected. Meanwhile, the path calculated by the novel algorithm has a higher match degree with the reference trajectory, and the positioning errors of the 2-D and 3-D trajectories are both less than 0.5 per cent.

Besides zero velocity update, another two problems, namely, heading drift and altitude error in the PNS, are solved, which ensures the high positioning precision of pedestrian in indoor and outdoor environments.

THE variation of full throttle engine brake horsepower with altitude at constant rotational speed is a matter of great importance to aircraft designers and those concerned with the measurement of aircraft performance. For the former its main importance probably lies in the design of aeroplanes intended for high altitude use where accurate knowledge of the engine power available is of paramount importance in the evolution of a successful aircraft. In the measurement of aircraft performance it is necessary to reduce the observed results at non‐standard atmospheric conditions to those obtaining under the chosen standard conditions, and for this it is essential that the variation of engine power with altitude is well established.

This study aims to design a new low-cost localization platform for estimating the location and orientation of a pedestrian in a building. The micro-electro-mechanical systems (MEMS) sensor error compensation and the algorithm were improved to realize the localization and altitude accuracy.

The platform hardware was designed with common low-performance and inexpensive MEMS sensors, and with a barometric altimeter employed to augment altitude measurement. The inertial navigation system (INS) – extended Kalman filter (EKF) – zero-velocity updating (ZUPT) (INS-EKF-ZUPT [IEZ])-extended methods and pedestrian dead reckoning (PDR) (IEZ + PDR) algorithm were modified and improved with altitude determined by acceleration integration height and pressure altitude. The “AND” logic with acceleration and angular rate data were presented to update the stance phases.

The new platform was tested in real three-dimensional (3D) in-building scenarios, achieved with position errors below 0.5 m for 50-m-long route in corridor and below 0.1 m on stairs. The algorithm is robust enough for both the walking motion and the fast dynamic motion.

The paper presents a new self-developed, integrated platform. The IEZ-extended methods, the modified PDR (IEZ + PDR) algorithm and “AND” logic with acceleration and angular rate data can improve the high localization and altitude accuracy. It is a great support for the increasing 3D location demand in indoor cases for universal application with ordinary sensors.

The purpose of this paper is to introduce a low-cost quadrotor that can be used for educational purposes and investigate the applicability of a low-cost MEMS laser sensor for accurate altitude control.

A single printed circuit board is designed to form the structure of the quadrotor. A low-cost MEMS motion sensor, a microcontroller and four small motors are mounted on the board. A separate laser sensor module measures the altitude. A remote controller is designed to control the quadrotor’s motion. The remote controller communicates with the quadrotor via wireless connection. Roll and pitch attitude stabilization is achieved using the proportional and derivative control algorithm. The applicability of an MEMS laser sensor for altitude control is also studied.

The low-cost quadrotor works well even though its body structure is made using a printed circuit board. Low pass and Kalman filters work well for attitude estimation and control application. The laser sensor is very accurate and good for altitude feedback; however, it has a relatively short measurement range and its sampling rate is relatively slow, which limits its applications. The vertical velocity obtained by differentiating the laser altitude has delay and inhibits suitable damping. Using the vertical velocity obtained by integrating the vertical accelerometer’s output, the damping performance is improved.

Developing a low-cost quadrotor that can be used for educational purposes and successfully implementing altitude control using a laser sensor and accelerometer.

Individuals who ascend to altitude too rapidly invariably develop acute mountain sickness (AMS) although a high carbohydrate diet may lessen these symptoms. Specific questions addressed in this study were: changes in diet prior to sojourning at altitude; changes in food consumption/nutritional intake, food acceptability, flavour and taste intensities. Nineteen subjects assembled for three days at sea level for baseline measurements consuming a diet of dehydrated rations. This regimen was repeated 18 days later in the Bolivian Andes at approximately 5,600m once subjects were acclimatised. Results confirm a common phenomenon; a reduced dietary intake and body weight loss at high altitude. Other results, flavour and taste intensities and overall food acceptability indicate the suitability of these foods in both environments.