JPH0260897A - Automatic landing device - Google Patents

Abstract

PURPOSE:To carry out self-controlled automatic landing by inputting signals from both a GPS receiver and an airframe sensor system, and obtaining the deviation of landing target airport runway information from standard glide path information, and then outputting it into an autopilot system. CONSTITUTION:After receiving the signals both from an on-board GPS receiver 1 for receiving the electric waves from an artificial satellite and from an airframe sensor system 4 for detecting the attitude angle, speed, altitude, and landing time of an aircraft, a computer 3 calculates the deviation of landing target airport runway information 2 from standard glide path information, and outputs the deviation correction value to an autopilot system 5. And, after receiving the signal from an airframe sensor system 4, the autopilot system 5 outputs a control signal to a flight and ground control system 9. In this manner, it is only necessary for a pilot to rectify the movement of aircraft and to correct the conditions as necessity arises so that the ordinary landing can be carried out, thus self-controlled automatic landing not depending on ground aids can be enabled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a system for ascertaining the position of an aircraft using waves from an artificial satellite, that is, GPS (GlobalPos+i
This invention relates to approach and landing equipment for small civil aircraft, etc., using

The device of the present invention can also be applied to general aircraft that land, unmanned spacecraft, etc.

[Conventional technology]

Conventionally, ILS (Instrum@nt Laudi
ng System) and MLS (Microwav
Automatic landing is carried out based on landing guidance provided by ground equipment such as the e-Landing System. And it is transitioning to the MLS system.

[Problem to be solved by the invention]

MLS is the only way to adopt an efficient landing method, such as a two-segment layer landing method, in which the rate of descent at high altitude and the rate of descent at low altitude are set to separate values. However, current automatic landing systems require extensive ground equipment, and the cost of rounding them up is extremely high.

Therefore, the present invention adopts GPS, is inexpensive and has high coverage, and
The objective is to provide an automatic landing system that enables efficient landing.

[Means to solve the problem]

The automatic landing system according to the present invention includes a GPS receiver that receives radio waves from an artificial satellite in order to determine the position of the aircraft, an aircraft sensor system that detects the attitude angle, speed, altitude, and time of touchdown of the aircraft, and the GPS receiver. Input signals from the receiver and aircraft sensor system,
A computer that calculates the deviation from the runway of the landing target airport and the standard glide/i4 base and outputs the deviation correction t to the auto/4 pilot system, inputs signals from the computer and the aircraft sensor system, and and an autopilot system that outputs a control signal to a ground control system.

[Effect]

In the present invention, automatic landing is performed not by setting a standard glide path using ground equipment (but by measuring the aircraft's position using GPS and setting a glide path for the target runway).

With GPS and computer, own aircraft position and glide/
In order to calculate the deviation from the 4's and correct the deviation,
Auto/ )4 Iro, To use the posture hold mode. Then, automatic landing is performed by operating the 72F'% landing gear, brakes, and steering.

〔Example〕

An example is shown in FIG.

The position of the aircraft is determined by information from the GPS receiver 1 mounted on the aircraft. The computer 3 calculates the runway and glide/i4 space information 2 of the landing target airport that has been input in advance and the 1 deviation between the aircraft's position and obtains the attitude angle information from the aircraft sensor system 4, and converts it into the aircraft axis information. Convert the coordinate axes. If the airport location is far away, information is input to the aircraft's navigation system to guide the aircraft to the target airport, but if it approaches the airport, it is required to take approach and landing procedures. In this case, the above deviation information is It is input to the aircraft's auto-noceirot system 5, and its output is input to the 7 light and ground control system 9 to control the aircraft.During this time, the altitude, speed, and ground information from the aircraft sensor 4 is obtained. 7. Perform leg operation 6, brake, and steering operation 7. Also,
/Archive, To operation 8 is auto pyro, To system 5
Incorporating it into the feed forward loop
The calculation method is shown below.

Using the symbols in FIG. 2, find the deviation e from the standard glide path.

If G is a unit vector of standard glide/flat, then HBf is the transformation matrix from the earth coordinate system to the aircraft coordinate system.
If = 77B y e Standard glide in the horizontal and vertical directions of the aircraft...The amount of deviation correction with respect to the base is ψ2゜f;・y m/e x m・
...(4) θref ” 'Ixm/*xx
° = = t51 Set this to the aircraft's auto mode.
This is input as a reference change for the attitude maintenance mode in the No4 Pilot System and is used to control the ride on the Glide Notas.

During this time, the altitude and speed of the aircraft are monitored, and the flag and landing gear are automatically operated at scheduled points.

(No) e After touchdown, the brakes are applied, the heading is maintained using the steering wheel, the runway center is automatically maintained, and an automatic landing is executed.

In addition, in this system, the stay is by /9 Ilot.

You can add operation pedal operations at any time. Auto
As a system, C3S (Control 5 Tiak
St...ring) Equipped with abilities such as Mote 9.

However, this results in 'fall-
aaf.'', making it an easy-to-use system with a simple hardware configuration.

3 to 6 show an overview of GPS and the configuration of a GPS reception point.

What is GPS?Global Pom1*1onlng 5
Abbreviation for yst@m, also known as NAVSTAR (Navlga
tion 8at@1lit@withTim@And
Also called ``Ranging''.

This system, as shown in Figure 3, is a positioning system that uses 18 artificial satellites orbiting around the earth, and can always be used to determine the latitude, longitude, and height of the receiving point anywhere in the world. It has the excellent feature that it is not only possible to accurately determine the moving speed and direction of the receiving point, but also the moving speed and direction of the receiving point.

The 11Nfl satellite is placed in six circular orbits with an inclination of 63°. Each orbit is spaced 60' from each other, and each orbit has three equally spaced satellites. The altitude of this satellite is approximately 20,000 km.
It orbits the Earth approximately once every 12 hours. In this system, three satellites are placed in orbit as backup in case any of the 18 satellites should fail.

As shown in FIG. 4, this system consists of three parts: a group of satellites in orbit, a group of ground stations, and a group of user receivers.

The orbit and satellite time of each satellite are observed by a monitor station and sent to a control station. The control station analyzes and predicts the orbit of each satellite and the satellite time based on observation data transmitted from the monitor station, and sends correction data for the orbit and satellite time to the satellite once a day. Update the satellite's memory contents.

User receivers receive signals from at least four satellites to determine their own position, but with this system, four or more satellites must always be within view in any region of the world. Among them, the combination of four satellites that gives the best positioning result is selected and used.

From GPS satellites, it is 1,575.42R called Lx.
KHz signal and 1,227.6 M called L2
HX signals are being transmitted.

The L1 signal and the L1 signal mainly carry navigation data for knowing the orbital position of each satellite. Spread spectrum modulation is used to add these data to the GPS signal.

Spread spectrum modulation is a technology that processes the signal to be transmitted using a type of cryptographic code called pseudo-noise and sends it with properties similar to noise.In GPS, this code is called the I code and the P code. using something.

C/A = 7-do is approximately I Mbpa (m@ga b
It has a relatively simple structure and is fast (5 seconds), and is used as an aid to capture the P code described below, but it can also be used for position measurement that does not require high precision. Can be used.

According to actual measurements, the C/A code has an accuracy of about 30 m.

On the other hand, P-code has a speed of about 10 Mbps and is suitable for high-altitude positioning, but it has a complex configuration and is said to be used exclusively for military or specially approved purposes.

Since each of the 18 satellites is assigned a different arm turn code, the GPS receiver internally uses the same arm turn code as the satellite it is currently trying to receive.
By generating an A code and correlating it with the received signal,
Only the transmitted data of the satellite that you are currently trying to receive is played back. Other satellites are also transmitting at the same L1 signal frequency, but since there is no correlation with the C/A code inside the GPS receiver, there is no interference and no interference.

The position of the reception point is calculated based on the distance from the reception point to the satellite, which is obtained by measuring the reception timing of these codes.

Now, assuming that the clocks of the GPS satellites and the clocks of the user's receiver are perfectly aligned, and the user's receiver receives signals from three satellites within its field of view, the GPS satellite will launch. The distance between each of the three satellites and the user receiver can be determined from the difference between the time of transmission of the signal and the time of reception of the signal received by the user receiver.

FIG. 5 shows how three satellites are used to determine the position.

If we consider a sphere whose radius is measured by the user receiver with the positions of the three satellites as the origin and the distance from the nine user receivers to the satellite, we can think of three spheres, and these three spheres are at one point. The intersection of the two is the location of the user's receiver, i.e.
It's height.

In an actual user receiver, it is difficult to accurately synchronize the clock inside the user receiver with the satellite clock, so it is necessary to calculate the error in the user receiver's clock as an unknown quantity. The unknown values that the user receiver should find are latitude,
Including the longitude and height, there are 4 in total. Therefore, in order to find these four unknowns, the actual original user receiver needs four unknowns.
Receive signals from satellites.

FIG. 6 is a diagram showing the basic implementation of a 90PS receiver using a high code.

C&) Antenna The antenna has -like directivity in the upper hemisphere.

(b) The 1,575.42 MHz (L) GPS signal received by the 7″ reamplifier is transmitted to the reamplifier installed near the antenna and amplified.

(e) Frequency conversion and amplification The output of the amplifier is guided into the reception processor, frequency converted, and then intermediate frequency amplified.

This intermediate frequency amplified GPS signal includes spread spectrum signals from all satellites flying above the reception point.

(d) Spectrum despread demodulation In order to extract the signal of the satellite that is currently being received from the intermediate frequency amplified 90PS signal, the reception processor receives the specific C/A code assigned to that satellite. Spectrum despread demodulation is performed by correlating with a GPS signal generated internally and amplified at an intermediate frequency.

If this spectrum despread demodulation is performed on four desired satellites, the GPS signals sent from the four satellites at the same frequency (L!) will be separated and demodulated.

(・n) In the distance measurement spectrum despread demodulator, if the phase of the code to be generated in the reception processor is controlled so that the correlation between this code and the received 90PS signal is maximized, the reception The phase of the C/A code generated in the processor is determined by the received G
This corresponds to the phase of the C/A code of the PS signal.

Therefore, the distance between the reception point and the satellite can be calculated from the phase of the round code generated within the reception processor.

(f) Doppler measurement spectrum Despread By measuring the carrier and frequency included in the demodulated GPS signal,
"Calculate the deviation.

From this Doppler shift, the rate of change in distance between the receiving point and the satellite can be determined.

(g) Trajectory data collection Spectral despreading Detect orbit information at a transmission rate of 50 bpm contained in the demodulated GPS signal, and collect orbit data.

(h) Calculate the accurate KJE position of each of the four satellites currently being received from the orbital data of the position calculation satellite, and use these values and the distance between the receiving point and the satellite found earlier to calculate 4. Set up the original simultaneous equations and solve them using successive approximation to find the position of the receiving point.

(1) Accurately calculate the movement of the four satellites currently being received from the orbit data of the moving speed/azimuth satellite, and calculate the moving speed of the receiving point from these values and the previously determined DOAG shift of the GPS signal.・Calculate the direction.

(J) Position, speed, and direction display The position, speed, and direction signals obtained in the above manner are
7Jf, 6° into the computer 3 shown in the figure. [Effects of the Invention] Since the apparatus of the present invention is configured as described above, it produces the effects described below.

(Inside the 11 aircraft, it calculates the deviation from the standard glide) 4th and controls to eliminate the deviation.

The f21 aircraft's auto/4'iro,to system controls the sequence of operations from aggrote to stopping the aircraft.

(3) Therefore, it is only necessary to correct the motion of the aircraft so that it can land normally, as necessary, and the operation becomes extremely easy.

(4) It is possible to form an autonomous automatic land-based device that does not rely on ground equipment.

[Brief explanation of the drawing]

Fig. 1 is a component diagram of the present invention, Fig. 2 is a layout diagram of the present invention,
FIG. 4 is a diagram of the GPS system, FIG. 5 is a diagram showing the positioning principle of GPS, and FIG. 6 is a diagram showing the basic configuration of a GPS receiver. 1...GPS receiver, 2...Airport runway information and glide/arm information, 3...Combi, -ta, 4...
・Aircraft sensor system, 5...Auto pilot system, 6...Hula, 7°, landing gear, etc. operation, 7...Brake/steering operation, 8...Pyro, t operation, 9.
...Flight Control System. Applicant's agent Patent attorney Takehiko Suzue [〉: 1: Seven tusk standard diagrams,! Coordinates and symbols of the system used cR components of the present invention GPS satellite layout diagram GPS system diagram

Claims (1)

[Claims] G receives radio waves from artificial satellites to know its own position
A PS receiver, an aircraft sensor system that detects the attitude angle, speed, altitude, and touch down of the aircraft, and signals from the GPS receiver and aircraft sensor system are input to determine the runway and standard glide path of the landing target airport. a computer that calculates the deviation between the two and outputs the deviation correction amount to the autopilot system;
An automatic landing system comprising an autopilot system that inputs signals from the computer and the airframe sensor system and outputs control signals to a flight and ground control system.