Japan Aerospace Exploration Agency

Hamaki Inokuchi

Takashi Asahara

Kazuhiro Asai

Nobuhiro Yokoyama

[Object] To provide a technique for reducing the fluctuation of an airplane when an airplane enters turbulence without using prior information of two-dimensional or more airflow vectors. [Solving Means] A system includes: a measurement unitthat emits electromagnetic waves toward a planned flight direction of the airplane, receives scattered waves of the emitted electromagnetic waves in atmosphere, and measures a remote wind speed in a radiation axis direction of the emitted electromagnetic waves based on a Doppler shift amount of a frequency between the emitted electromagnetic waves and the scattered electromagnetic waves; a spoilerthat controls a lift of the airplane; and a control calculation unitthat calculates an angle of attack with less lift inclination and calculates an angle of the spoilerthat controls the lift so that the lift does not change when it is determined that the airplane will receive a gust, based on a measurement result of the measurement unit

Gust alleviation system of airplane, turbulence detection system, fluctuation estimation system, doppler LIDAR, and gust alleviation method of airplane

[Object] To appropriately evaluate reliability of a reception signal. [Solving Means] A signal processing unitincludes a first integration unit, a Doppler detection unit, and a comparator circuitas a reliability index calculation unit. The first integration unitintermittently integrates a pulse train corresponding to a reception signal by using two systems and obtains two pieces of integrated data. The Doppler detection unitdivides each of the two pieces of integrated data into a plurality of range bins in time series, obtains a relationship between a frequency and intensity in each range bin for each of the two pieces of integrated data, and detects a Doppler shift amount from the relationship. The comparator circuitcalculates a reliability index of the reception signal by comparing the Doppler shift amounts (wind velocity values) of the two pieces of integrated data.

Signal processing device and signal processing method

An object of the present invention is to provide a method for preventing turbulence-induced accidents that can expand a detection range to about 20 km without increasing the size of a device or increasing the energy consumption, can perform planar distribution monitoring of turbulence when the turbulence is detected in the flight direction and also can output a signal for autopilot steering input that decreases the fuselage shaking when the turbulence is difficult to avoid, as well as to provide a device having those functions. In the method for preventing turbulence-induced accidents according to the present invention, an optical remote airflow measurement device of a Doppler lidar system using a laser beam is used to routinely enable distant turbulence to be detected by fixing a laser emission course in a flight direction and taking a long integration time of a reception signal, and to enable planar distribution of the turbulence to be displayed when turbulence is detected, by scanning the laser emission course in a horizontal direction and switching an image display to a two-dimensional display.

Airborne device for preventing turbulence-induced accidents

An object of the present invention is to provide a turbulence avoidance operation assist device that automatically generates an optimal trajectory of emergency avoidance and reports this trajectory to a pilot when distant turbulence is detected during an aircraft flight. The turbulence avoidance operation assist device in accordance with the present invention includes: means for detecting the presence of a danger region such as a turbulence region ahead of aircraft in a flight direction; means for representing the danger region as an assembly of rectangular solids when the detection means recognizes the danger region, and generating a flight trajectory by a local optimum solution of an avoidance trajectory using a convex quadratic programming method in which deviation from a reference trajectory is the smallest on the basis of an initial estimation solution obtained by a semidefinite programming method; and means for reporting the flight trajectory to a pilot.

Turbulence avoidance operation assist device

An object of the present invention is to provide an optical remote airflow measurement apparatus with which even colored noise corresponding to an external environment of the apparatus can be reduced, thereby reducing measurement reliability deterioration and enabling long-distance measurement in a wide flying speed range. A colored noise reduction method according to the present invention includes: considering a signal strength of scattered light to be substantially non-existent in a remotest region and beyond; calculating a noise distribution by performing processing to average the signal strength in respective Doppler frequency components divided at intervals of a certain frequency in the remotest measurement region and beyond, and performing subtraction processing in each of the Doppler frequency components on all signal strength distributions of the measurement region, which are obtained by dividing the noise distribution at intervals of a certain distance.

Colored noise reduction method and device for optical remote airflow measurement apparatus

A laser light reflection device for an aircraft-installed laser apparatus with which, when a function check is performed on the aircraft-installed laser apparatus by emitting laser light from a parked aircraft to a body exterior, the emitted laser light can be reflected in a desired direction safely and efficiently. A reflection mirror is capable of autorotation about at least an in-plane horizontal axis thereof, and a support ring is attached to the reflection mirror to be capable of rotating about an in-plane vertical axis and the in-plane horizontal axis of the reflection mirror. A laser pointer unit formed by inserting a laser pointer into a sleeve pipe is attached to the support ring so as to be oriented toward an in-plane of the reflection mirror. A guide scope is attached to the support ring such that an optical axis thereof matches an optical axis of the laser pointer unit.

Device to reflect in a desired direction a laser beam emitted by a laser device mounted with an aircraft

An object of the present invention is to provide a device which detects matter suspended in air, represented by, for example, ice crystals, volcanic ash, in the forward direction of the flight of an aircraft. A method of detecting matter suspended in air of this invention is characterized in that, in airborne Doppler LIDAR using laser light, components of matter subjected to laser light reflection and scattering are remotely measured on a basis of an angular difference in planes of polarization of transmitted light which is laser light radiated into the atmosphere, and received light scattered by matter suspended in air in a remote region.

Airborne LIDAR for detecting matter suspended in air

The object of the present invention is to provide an air data sensor that does not require an external input of a reference velocity as a Doppler LIDAR, has a function of autonomously determining the absolute airspeed, and has no position error. The optical air data sensor in accordance with the present invention is an optical air data sensor, mounted on an aircraft, for emitting a laser light as a transmission light into atmosphere, and then receiving a laser scattered light produced by scattering of the laser light by aerosol present in the atmosphere as a reception light, thereby to measure an airspeed and a wind velocity of airflow in a distant region on the basis of a Doppler shift amount between the transmission light and the reception light, wherein a true airspeed is autonomously measured, without setting a reference velocity, by successively sweeping a frequency offset corresponding to a reference velocity for providing an offset to a measurement frequency, and performing this sweeping within a frequency range in which the Doppler shift amount is measured.

Growing community of inventors

Tokyo, Japan

Hamaki Inokuchi