The statistics complied by the Boeing Co. show that the accident rates of commercial jet airplanes have been kept constant at a low level for the past 30 years or so. The accident rate remains constant, as an increase in number of accidents is predicted due to expansion of air traffic. Therefore, a new technology that is able to further decrease the accident rate is required. Human error like pilot's mistake could be mentioned as the most important factor of aircraft accidents. Especially, human errors, which occur at abnormal situations such as OEI or control surfaces failure, seem to become the direct causes of an accident. In the present study, a control support system is constructed by using our proposed linear model matching control method, which is capable of recovering the controllability under an OEI situation of a multiengine plane, with the object of preventing an accident due to situational pilot error.
We are pursuing the research and development of a practical airborne Doppler LIDAR that will detect air turbulence which is a major cause of significant injuries and aircraft damages. Although a longer detection range of air turbulence could be achieved by using higher powered laser to give advanced warning to crew and passengers, it implies larger and heavier devices which are not suitable for airborne applications. We introduce a colored noise reduction method which reduces the measurement errors and extends the measurement range for the air turbulence detection. We show that the detection range of air turbulence is improved by about 40% using the colored noise reduction method.
IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is the world's first solar sail demonstration spacecraft. It was launched in May 2010 and has 14-m-square solar sail. Solar sail is a propulsion system which accelerates the spacecraft with the solar radiation pressure, and its performance is largely affected by its unevenness. In order to recover a shape of the sail in the space, pictures of IKAROS taken in the space with cameras separated from the main body are used because of its structural complexity. There are two types of image analysis method and in this paper shape from shading method, in which the brightness of pixels is focused on, is adopted. Since there are some causes of image degradation and they are difficult to model, some cases are verified to know the detail characteristics. This paper presents the approach for analyzing the pictures to obtain the shape of IKAROS sail, and compares the result with the one of another image analysis method and flight data of the attitude motion.
This paper describes the design of novel control system for a fixed-wing Unmanned Aerial Vehicle (UAV) which can transition between level flight and hovering. The control system is constructed by using dynamic inversion method applying to the translational and rotational nonlinear equations of motion of the UAV. In the controller design for the rotational motion, an observer based on Disturbance Accommodating Control (DAC) method is used to estimate nonlinear parameters. Moreover, H∞ controller is employed to have robustness against estimation error and modeling error on its dynamics. In order to verify the validity of the proposed control system, numerical simulation is performed for the UAV.