DE102006003199B3 - Sensor for wind turbulence measurement, especially for reducing gust loading, preferably for aircraft, has controller that controls positioning signals depending on combined wind signal - Google Patents

Abstract

The device has a LIDAR sensor (10) for predictive wind turbulence measurement, a wind sensor (12) for measuring instantaneous wind turbulences, a signal processing device (14) for combined processing of the sensor signals to produce a combined wind signal (Wk) and a controller (28) that controls positioning signals depending on the combined wind signal. An independent claim is also included for a device for wind turbulence measurement.

Description

The Invention relates to a sensor device for wind turbulence measurement, especially for gust load reduction, the preferably in aircraft, but also in motor vehicles and the like is used. Furthermore, the invention relates to a method for Wind turbulence measurement, in which case in particular the sensor device used for wind turbulence measurement.

The Manufacturers of modern wide-body aircraft subject a strong competitive pressure. The requirements regarding economy / fuel consumption The aircraft are gaining in terms of rising kerosene prices increasing importance. The reduction of the weight by lighter construction of the aircraft components (eg wing, fuselage) contributes decisively to reduce fuel consumption. The potential for Reduction of aircraft weight is limited by so-called dimensioning loads that withstand the aircraft structure got to. This includes among other things also loads, caused by the influence of wind gusts become.

Of the Use of a gust load reduction system allows the reduction of these loads in the range of 30-50% and an associated saving in the structural weight of several a hundred kilos. In the context of the gust load reduction it is of particular importance to reduce the load peaks, by so-called discrete gusts be caused. A discrete gust will be by a time limited, usually very short, strong-wind gust (wind speed change until to 20 m / s). The reduction of the caused thereby Loads are caused by a temporally coordinated rash of shelves (eg symmetrically deflecting ailerons, spoilers, elevators etc.). Due to the limited dynamics (limited positioning rate) of these shelves it is necessary the shelves even before the impact of the gust on the airplane wing to activate. This will ensure that the footprint is at Arrival of the gust on the airplane wing are sufficiently extended to the influence of the gust on the Compensate aircraft structure. At low aircraft speeds (less than Mach 0.5, eg at takeoff and landing) offers one Measurement of the gust sufficient with a wind sensor or a wind vane on the nose of the aircraft Time to the shelves until the gust occurs on the wing to activate. At higher Airplane speeds as they occur in normal cruising flight sets the sufficiently early activation the footprint the use of a predictive sensor that anticipates the wind at a defined distance (order of magnitude 50-150 m) in front of the aircraft.

in the The EU Project AWIATOR has become a forward-looking LIDAR (Light Detection and Ranging) developed sensor with which it is possible Wind turbulence / gusts to measure at a defined distance in front of the aircraft. This Wind signal is then used to control a gust load reduction system become. Examinations of the sensor have shown that the accuracy of the Sensors for continuous use in a gust load reduction system sufficient.

From K. -U. Hahn and R. King ATTAS Flight Test and Simulation Results of the Advanced Gust Management System LARS, at AIAA Atmospheric Flight Mechanics Conference, Hilton Head, South Carolina USA 1992, as well as R. König and K.-U. Hahn Load Alleviation and Ride Smoothing Investigations Using ATTS, in Proceedings of the 17 ^th Congress of the International Council of the Aeronautical Sciences, Stockholm, Sweden, in 1990, the use of a Böenlastabminderungssystems is known. As a wind sensor, a "nose boom" was used, which is firmly attached to the nose of the aircraft and at low speeds sufficient time to knock out the shelves offers. The accuracy of the sensor was also sufficient for the gust load reduction and good results could be achieved. The investigations, however, were limited to low airspeeds and low altitudes, which are clearly exceeded by modern wide-body aircraft.

in the As part of a NASA research project in 1996 was the opportunity investigated for the use of a LIDAR sensor for gust load reduction (D. Soreide, R. Bogue, L.J. Ehemberger and H. Bagley, Coherent Lidar Turbulence Measurement for Gust Load Alleviation, in NASA Technical Memorandum 104318, NASA Dryden Flight Research Center, Edwards, California 93523-0273, 1996). In this project, wind turbulence was measured using two LIDAR sensors determined and there have been studies to improve signal accuracy Use of a stronger one Lasers for the LIDAR sensor. The sensor device used in the NASA project however, wind turbulence measurement is only suitable for low altitudes. Furthermore, the use leads a stronger one Lasers due to his big Own weight to increase of the aircraft weight.

in the The EU AWIATOR project has become a novel LIDAR sensor developed, which also works at higher altitudes. This ensures that you can gust even at cruising altitudes and can measure at cruising speeds. However, the accuracy is of the sensor is not sufficient for the continuous operation of a gust load reduction system.

FR 2870942 describes an aircraft with a LIDAR sensor for measuring wind turbulence. Further, additional sensors are provided which sense the effects of a command transmitted to the control surfaces of the aircraft. There is a regulation of the floor space signals by different aircraft conditions are determined by the sensors.

US 6,666,410 describes a sensor device for wind turbulence measurement for a rocket, wherein a wind detection system is used with a LIDAR sensor. Optionally, the sensor device may comprise a radar. The aim of the described device is to determine the speed and direction of the wind.

task The invention is a sensor device for wind turbulence measurement and to provide a method of wind turbulence measurement with which or with the improved prediction accuracy occurring Gusts is possible.

The solution The object is achieved according to the invention by a sensor device according to claim 1, and a method for wind turbulence measurement according to claim 8th.

The Sensor device according to the invention for Wind turbulence measurement is particularly suitable for gust load reduction. Method for reducing gust load are used in aircraft but are also used in motor vehicles, as well as for rail vehicles. This can, for example the crosswind stability improved and / or issued a warning signal. The sensor device according to the invention has a LIDAR sensor for predictive wind turbulence measurement on. The LIDAR sensor thus generates a first wind signal. A suitable LIDAR sensor is the LIDAR sensor developed within the EU project AWIATOR. Furthermore, the sensor device according to the invention a wind sensor for measuring the current wind turbulence. As a wind sensor are conventional Wind vane sensors suitable for use in commercial aircraft. The wind sensor generates a second wind signal. According to the invention the two wind signals in a signal processing device with each other connected or combined. After processing the two wind signals in the signal processing device, it is thus possible, the Time advantage, as determined by the predictive LIDAR sensor Wind signal, with the accuracy of that obtained by the wind sensor second wind signal to combine. Investigations have shown thereby improving the accuracy compared to the immediate use of a LIDAR sensor of approximately 50% can be. The output from the signal processing device combined wind signal is then forwarded to a control device.

The Control device controls in dependence the combined wind signal adjusting devices. At the adjusting devices is the use of the sensor device according to the invention in aircraft for example, the control of lateral rovers, spoilers, elevators etc. In motor vehicles can by the actuator a signal be spent on the steering and / or brakes. Also the Output of a warning signal is possible.

In a preferred embodiment takes place in the signal processing device under consideration a runtime difference the calculation of the combined wind signal. For this purpose, the two sensors are to take into account a transit time difference between the first, generated by the LIDAR sensor, and the second, from the wind sensor generated wind signal, in particular in the direction of movement of the aircraft, the motor vehicle or the rail vehicle, in a spatial Spaced apart.

Further can in a preferred embodiment by the signal processing, the speed of the aircraft or Vehicle considered become.

wobei d_LIDAR-VANE den Abstand zwischen LIDAR-Sensor und Windfahnensensor und V die Flug- bzw. Fahrzeuggeschwindigkeit beschreibt.The transit time difference T of the LIDAR signal w _LIDAR and the wind _vane signal w _vane can be calculated by:

where d _{LIDAR-VANE describes} the distance between LIDAR sensor and wind vane sensor and V the flight or vehicle _speed .

Preferably, a time derivation of the wind signal is calculated in a derivation element integrated into the signal processing device. This is calculated by:

Preferably the signal processing device further preferably has a the diverter downstream integrator for the integration of temporal Derivation of the wind signal. The temporal integration takes place preferably continuously from start to landing.

To further improve the accuracy of the combined wind signal, the signal processing device may include a return loop. In the return loop the determined is combined te wind signal subtracted from the wind signal measured by the wind sensor and then again using the integrator determined a combined wind signal. The feedback loop is preferably executed in each calculation step for correction.

Further includes the signal processing device in a preferred embodiment Filtering devices on. In particular, a filter device provided between the diverter and the integrator. Another Filtering means can be provided in the return loop be. Preferably, the filters are by propere, rational transfer functions described, together with the transit time difference, or the Selection of the look-ahead range of the LIDAR sensor are designed. hereby the accuracy of the combined wind signal can be improved.

Further The invention relates to a method for wind turbulence measurement, wherein to carry out of the method, in particular the sensor device described above is used. According to the method of the invention is determined by means of a LIDAR sensor for predictive wind turbulence measurement generates a first wind signal. By means of a wind sensor for measurement current wind turbulence, a second wind signal is generated. According to the invention the two wind signals for generating a combined wind signal combined together. By combining a forward-looking Windsignals with a very accurate current wind signal can be good Results are achieved in the wind turbulence measurement.

The inventive method is, as described above with reference to the sensor device, advantageous further training. In particular, the determination of the combined Windsignal a transit time difference of the signals and / or the aircraft or Vehicle speed taken into account. It is particularly preferred for determining the combined wind signal to use the equations described above and in particular to perform an integration of the derived wind signal.

following The invention will be explained in more detail with reference to accompanying drawings.

It shows:

1 a schematic block diagram for determining the combined wind signal,

2 a block diagram of a simulation for validation of the signal combination according to the invention,

3 on the basis of 2 carried out simulation time profiles of the wind signal W _{VANE of} the combined wind signal w _k and the LIDAR signal W _LIDAR and

4 in accordance with 2 Simulation obtained time profiles of the noise components or the error in the signals w _LIDAR and w _k .

With the aid of a LIDAR sensor attached to an aircraft, for example 10 a first wind signal w _{LIDAR is} generated. With a wind sensor also attached to the plane 12 a second wind signal w _{VANE is} generated. The two wind signals are sent to a signal processor 14 transmitted. In the signal processing device 14 is in a diverting element 16 calculated according to equation 2, the derivative of the wind signal ẇ and a filter 18 fed. After filtering the signal ẇ this becomes an integrator 20 integrated, so that after the integrator a combined wind signal w _k is present. In a return loop 22 is from the wind signal w _VANE the current combined wind signal w _k in one element 24 subtracted, a filter 26 fed and then in turn to the integrator 20 transmitted. After passing through the return loop 22 the signal w _{k is sent} to a control device 28 transmitted.

To validate the inventive concept, as was 2 can be seen, carried out a simulation assuming appropriate boundary conditions.

For the simulative validation of the concept, the arrangement in 2 selected. The inaccurate LIDAR signal w _LIDAR is generated by adding mean-free, Gaussian noise with variance 1 on a wind signal (continuous turbulence, Dryden spectrum, L = 762 m). The wind vane signal is generated by a time delay (delay time T) of the wind signal. The aircraft speed is 248 m / s. The filter 18 ( 1 ) is described by the constant gain k ₁ and the filter 26 ( 1 ) is described by the transfer function k ₂ + k ₃ / s. The constants k ₁ , k ₂ , k ₃ and the time T have been optimized so that the noise component in the signal w _{k is} minimized. As a constraint in the optimization, it was determined that the period of time from the determination of the gust to its impact on the aircraft wing must be greater than 190 ms in order to guarantee a sufficient foresight. An optimization run provided
K ₁ = 37.8, K ₂ = 7.98, K ₃ = 0.498, T = 0.216s

With this parameterization, the variance of the noise component in w _k could be reduced to 0.51. To visualize the results show 3 and 4 the time courses of a simulation over 10 seconds.

The upper graph in 3 shows the global time course of the wind signals, the lower graph for better illustration, the curves in the range of 8-8.5 s increases. In the enlarged view, a clear improvement in the wind estimate compared to the LIDAR signal can be seen. Likewise, the improvement of the signal quality over the entire simulation period is based on the representation of the noise components or errors in the signals in 4 clear to see.

Claims (14)

Sensor device for wind turbulence measurement, in particular for gust load reduction, preferably for aircraft, with a LIDAR sensor ( 10 ) for predictive wind turbulence measurement, a wind sensor ( 12 ) for measuring momentary wind turbulences, one with the LIDAR sensor ( 10 ) and the wind sensor ( 12 ) connected signal processing device ( 14 ) for the combined processing of the sensor signals (w _VANE and w _LIDAR ) to produce a combined wind signal (w _k ), and one with the signal processing device ( 14 ) ( 28 ), which controls actuators depending on the combined wind signal (w _k ). Sensor device according to claim 1, characterized in that the LIDAR sensor ( 10 ) and the wind sensor ( 12 ) are arranged to determine a transit time difference (T) in a spatial distance from one another, wherein the transit time difference (T) in the determination of the combined wind signal (w _k ) is taken into account. Sensor device according to claim 1 or 2, characterized in that the signal processing device ( 14 ) a dissipation element ( 16 ) for generating the time derivative (ẇ) of the interconnected sensor signals. Sensor device according to claim 3, characterized in that the discharge element ( 16 ) an integrator ( 20 ) is connected downstream of the integration of the time derivative (ẇ) of the wind signal. Sensor device according to claim 4, characterized in that the signal processing device ( 14 ) a return loop ( 22 ) in which, in order to improve the combined wind signal (w _k ), the integrator ( 20 ) a difference signal from the current combined wind signal (w _k ) and from the wind sensor ( 12 ) measured wind signal (w _VANE ) is supplied. Sensor device according to one of claims 3 to 5, characterized in that between the discharge element ( 16 ) and the integrator ( 20 ) a filter device ( 18 ) is provided. Sensor device according to claim 5 or 6, characterized in that in the feedback loop ( 22 ) a filter device ( 26 ) is provided. Method for wind turbulence measurement, in particular using the sensor device according to one of claims 1 to 7, in which by means of a LIDAR sensor ( 10 ) for predictive wind turbulence measurement, a first wind signal (w _LIDAR ) is generated by means of a wind sensor ( 12 ) for measuring instantaneous wind turbulence, a second wind signal (w _VANE ) is generated, and the two wind signals (w _LIDAR and w _VANE ) for generating a combined wind signal (w _k ) are combined. Method according to Claim 8, in which a transit time difference (T) and / or an aircraft / vehicle speed (V) are taken into account for determining the combined wind signal (w _k ). Method according to Claim 8 or 9, in which, for the determination of the combined wind signal (w _k ), a time derivative (ẇ) of the wind signals (w _VANE , w _LIDAR ) which are linked together, in particular according to

he follows. Method according to one of claims 8 to 10, wherein the Determination of the combined wind signal the time derivative (ẇ) is integrated. Method according to Claim 11, in which an interration is carried out for improving the combined wind signal (w _k ), in which an integrator ( 22 ) a difference signal from the current combined wind signal (w _k ) and from the wind sensor ( 12 ) measured signal (w _VANE ) is supplied. Method according to one of claims 8 to 12, wherein the derived wind signal (ẇ) is filtered. A method according to claim 12 or 13, wherein while the interration is filtered.