JP2871426B2 - Method of analyzing trajectory of dropped object and control method of relative coordinates between dropped mother machine and measuring machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing the trajectory of a dropped object from a dropping mother machine, and more particularly to an analysis method for obtaining an accurate analysis result, and a dropping mother machine and a measuring machine for guaranteeing an accurate analysis result. And a method of controlling the relative coordinates of

In recent years, equipment used by dropping from a dropping mother machine during flight has been developed, and rescue supplies have been dropped for a long time. Since these dropped objects must be landed at an accurate position, it is necessary to accumulate data for that purpose. For that purpose, it is important to develop a technique for accurately analyzing the trajectory of the dropped objects.

[0003]

2. Description of the Related Art In order to analyze the trajectory of a dropped object, a method of mounting a radio wave source, an infrared light source, and a small amount of isotope on the dropped object, or measuring a drop situation by mounting a camera on a dropping base machine or a measuring machine. There is a way to record.

[0004] Among them, the former has a problem that some equipment must be provided for a dropped object, and it cannot be applied to a dropped object having a small margin in volume. On the other hand, the latter has a drawback that if the relative coordinates of the dropping mother machine and the measuring machine fluctuate, the obtained trajectory becomes inaccurate.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to provide an analysis method for accurately determining a trajectory and a method for controlling relative coordinates between a dropping mother machine and a measuring machine which are important for that purpose. Aim.

[0006]

FIG. 1 shows the principle of the present invention. In FIG. 1, 1 is a dropping mother machine, 2 is a measuring machine, and 3 is a dropped object.

According to the principle of the present invention, a beam having a predetermined frequency is emitted from a measuring instrument, the difference between the frequencies of reflected beams from the dropping base unit and the dropped object is determined, and the horizontal moving distance of the dropped object is determined from the frequency difference. Is calculated.

FIG. 2 shows a second principle of the present invention. FIG.
, 1 is a dropping mother machine, 3 is a dropped object, 4 is a measuring machine for measuring by photograph, and 11 and 12 are reference points provided on the dropped mother machine.

According to the second principle of the present invention, two reference points are provided on the body of the dropping mother machine, and the trajectory is determined based on the body coordinate system composed of a straight line passing through these reference points and a straight line perpendicular to the reference points. To analyze.

FIG. 3 shows a third principle of the present invention. FIG.
In (a), 1 is a dropping mother machine, 4 is a measuring machine, 13 and 1
Reference numeral 4 denotes a beam reflector provided in the dropping mother machine.

According to a third principle of the present invention, one beam is emitted from each of two predetermined locations of the measuring machine toward two predetermined locations of the dropping mother machine, and the two beams are emitted. Is detected by the measuring instrument.

[0012]

According to the principle of the present invention, the frequency of the reflected beam measured by the measuring device is shifted from the frequency of the irradiation beam by a frequency corresponding to the relative speed of the dropper and the measuring device and the relative speed of the dropped object and the measuring device. Therefore, if this frequency difference is obtained and integrated over time, the moving distance of the dropped object in the horizontal direction can be determined. By combining this with the vertical movement distance based on the law of natural fall, the trajectory of the dropped object can be obtained.

According to the second principle of the present invention, since the body coordinate system is set, the trajectory of the dropped object can be accurately measured based on the body coordinate system. An aircraft is flying with a large number of instruments, and keeps track of the tangent (horizontal direction) of the earth and the perpendicular to it, that is, the earth coordinate system. Therefore, if the trajectory obtained from the body coordinate system is converted into the earth coordinate system, the trajectory of the dropped object can be obtained accurately.

According to the third principle of the present invention, reflected beams of beams emitted from two places on the machine side of the measuring machine toward two places on the machine side of the dropping mother machine are detected at two places on the machine side of the measuring machine. I do. If the two aircraft are detected in parallel at the origin of the two detection points, it is pre-arranged that they are parallel, for example, when the coordinates of the detection points are displaced in the horizontal direction at both locations, the two aircraft will However, it is detected that the direction of the aircraft is not parallel, and the data can be fed back to the flight control device to fly at the same angle and parallel.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of the present invention will be described in more detail. FIG. 1B shows the frequency of the reflected beam of the beam emitted by the measuring instrument, that is, the Doppler frequency. In this case, the case where the dropping mother machine and the measuring machine are flying at a constant relative speed is illustrated, so that the Doppler frequency from the dropping mother machine is constant regardless of time. On the other hand, the topler frequency of the reflected beam from the dropped object is equal to the Doppler frequency of the reflected beam from the dropped base machine immediately after the drop, so the relative speed between the dropped object and the measuring instrument over time elapses. As it changes, the Doppler frequency changes.

The horizontal speed of the dropping mother machine, the horizontal speed of the dropped object, and the horizontal speed of the measuring machine are represented by v ₁ , respectively.
Assuming that v ₂ and v ₃ , c is the propagation speed of the beam, and f ₀ is the frequency of the output beam, the Doppler frequency f ₁ of the reflected beam from the dropping base unit and the Topler frequency f ₂ of the reflected beam from the dropped object are It is given by the following equation.

F ₁ = 2 (v ₃ −v ₁ ) f ₀ / c (1) f ₂ = 2 (v ₃ −v ₂ ) f ₀ / c (2) Accordingly, the difference Δf of the Doppler frequency is Δf = 2 (V ₁ −v ₂ ) f ₀ / c (3)

Accordingly, the moving distance D of the dropped object in the horizontal direction is
Is obtained by D = {(v ₁ −v ₂ ) dt = (c / 2 · f ₀ )} Δfdt (4)

FIG. 1C shows the moving distance. However, strictly speaking, equation (4) holds when the dropped object and the measuring instrument are always kept horizontal. Generally, as the dropped object falls, the line connecting the measuring instrument and the dropped object increases in angle. Assuming that the angle between the line connecting the dropped object and the measuring instrument at a certain point and the horizontal line is θ, the horizontal moving distance Δ of the dropped object near θ
D (θ) is given by the following equation.

ΔD (θ) = (v ₁ −v ₂ ) Δt = (c / 2 · f ₀ · cos θ) Δf · Δt (5) Accordingly, when the dropped object lands at ΔD (θ) from θ = 0 By integrating up to the value of θ, the entire horizontal movement distance can be obtained.

Since the vertical movement follows the law of natural fall, the fall distance is easily obtained, and the trajectory can be obtained by combining the horizontal movement distance and the fall distance.

Since the frequency measurement accuracy is the highest among the techniques for measuring physical quantities, the trajectory analysis method according to the principle of the present invention gives a very accurate trajectory calculation result. By the way, generally, a dropped object is much smaller than a dropped mother machine. Therefore, immediately after the drop, the reflected beam of the dropped mother unit and the reflected beam of the dropped object cannot be distinguished from each other physically because of the shadow of the dropped mother unit. Sometimes, the reflected beam of the dropped object is buried in noise and the accurate Doppler frequency cannot be measured. Therefore, it is preferable to take a photograph by flying with a photo-measuring device, and analyze the locus immediately after dropping from the photograph. However, since both the dropping mother machine and the measuring machine are floating in the air, there is no coordinate system as a reference for analyzing the trajectory.

The second principle of the present invention is to determine a reference coordinate system so that a trajectory can be accurately analyzed. As shown in FIG. 2, two reference points are provided on the machine side of the dropping mother machine, a straight line passing through the two reference points is set as one coordinate axis x, and a straight line perpendicular to this is set as another coordinate axis z. Determine the coordinate system. Therefore, if a continuous photograph is taken in a state where the dropping mother machine and the measuring machine do not relatively move, and the trajectory is drawn based on the body coordinate system, the trajectory with respect to the determined coordinate system can be obtained. On the other hand, an aircraft is equipped with a large number of instruments, and data on the angle of the aircraft with respect to the horizontal direction can be obtained from data on instruments for flight. Therefore, an earth coordinate system consisting of a tangent to the earth and a perpendicular thereto can also be determined.

Assume that the body coordinate system is an xz system, the earth coordinate system is an x'-z 'system, and the angle between the x-axis and the x'-axis is α. When the origins are matched, the coordinates in the x'-z 'system are given by the following equations.

X ′ = x · cos α + z · sin α (6) z ′ = z · cos α−x · sin α (7) Accordingly, the trajectory of the dropped object can be obtained from the equations (6) and (7).

FIG. 3B shows a method for detecting that the two aircraft are not flying in parallel. FIG. 3B illustrates the case where the two aircraft are flying at the same angle with respect to the horizon. In FIG. 3B, reference numeral 13 denotes one of the reflection points provided on the machine side of the dropping mother machine, and reference numeral 41 denotes a beam detector provided on the machine side of the measuring machine. This beam detector can emit a beam from one point, and the beam detection elements are arranged in a line including the beam emission point. Now, it is assumed that when the two aircraft are flying in parallel, the detection element at the beam emission point is set in advance so as to detect the reflected beam. If the actually detected elements are different elements, it can be detected that they are not flying in parallel, so the feedback is fed back to the flight control device of the measuring instrument so that the deviation amount is zero, and the deviation is always zero. , You can guarantee the parallel flight of the two aircraft. The above assumes that the two aircraft are flying at the same angle, but in practice the angles are different and
May fly without keeping parallel. Therefore, although an example in which the detection elements are arranged one-dimensionally has been described above, in order to cope with such a reality, the detection elements are arranged two-dimensionally, and such detection elements are arranged in two places. If the deviation of the coordinates between the detection point and the point to be detected in two dimensions is detected and fed back to the flight control device so as to make this deviation zero, the flight angle and parallelism can always be maintained.

FIG. 4 shows the third principle of the present invention applied.
This is a method to keep the interval between two aircraft. In FIG. 4, only the necessary parts of the two machines are enlarged, 1 is the dropping mother machine, 4 is the measuring machine 1
Reference numerals 5 and 16 denote reflection points on the machine side of the dropping mother machine, reference numeral 42 denotes a point for emitting a beam and detection of a reflected beam, and reference numeral 43 denotes a point for detecting a reflected beam. Now, if the reflected beam can be detected by the detecting element of the outgoing point of 42 and the detecting element of the predetermined coordinates of 43, the length between them is set to 2a, and the angle of the beam from the outgoing point to the reflecting point 16 is measured from the measuring machine side. If you measure φ,
The spacing between the two aircraft is given by a · tan φ. In this case as well, the gap between the two aircraft can be maintained more accurately by detecting the deviation of the detection points and feeding it back to the flight control device.

In the above description, the medium to be radiated or emitted is defined as a "beam", but the beams that can be used here are radio waves, light, and ultrasonic waves. When calculating the moving distance based on the frequency of the reflected beam, any of them can be used.If the radio wave absorber is coated on the machine side, light and ultrasonic waves are appropriate, otherwise, radio waves are also used it can. On the other hand, if the relative coordinates of the two aircraft are controlled by emitting the beam and detecting the reflected beam, the difference between the detection points of the reflected beam is very small, so that light and ultrasonic waves can normally be detected accurately, Radio waves can be used if the frequency is as high as a millimeter wave.

[0029]

As described above, according to the present invention, a method for accurately analyzing the trajectory of a dropped object from a dropping mother machine and a method for controlling the relative coordinates of the dropping mother machine and the measuring machine which are important for the method are realized. Is done.

[Brief description of the drawings]

FIG. 1 illustrates the principle of the present invention.

FIG. 2 shows the second principle of the present invention.

FIG. 3 shows a third principle of the present invention.

FIG. 4 is a method for maintaining an interval.

[Explanation of symbols]

 1 Dropping mother machine 2 Measuring machine 3 Dropping object

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01C 15/00-15/14 G01C 11/00-11/34 G01S 7/00-7/66 G01S 13/00-13 / 95

Claims (4)

(57) [Claims] 1. A method for analyzing the trajectory of a dropped object dropped from a dropping mother machine in flight, wherein a horizontal moving distance from the dropping mother machine is measured by a measuring machine (1) flying with the dropping mother machine (1). 2) irradiating a beam having a predetermined frequency, measuring a frequency difference between the reflected beam from the dropping base machine and the reflected beam from the dropped object (3), and integrating the frequency difference with time. The moving distance in the vertical direction is calculated according to the law of natural fall, and the trajectory of the dropped object is calculated. 2. A dropping base machine is provided with two reference points, and a body coordinate system which is determined by the attitude of the dropping base machine is set by using a coordinate axis passing through the two reference points and a coordinate axis perpendicular to the coordinate axes. From the photograph measurement results, the locus of the dropped object is obtained based on the aircraft coordinate system, and the obtained locus is composed of a coordinate axis parallel to the tangent to the earth and a coordinate axis perpendicular to the tangent to the earth. A method for analyzing the trajectory of a dropped object, in which the trajectory of the dropped object is calculated by converting the coordinates into a coordinate system. 3. A beam is emitted from two predetermined locations of the measuring machine toward two predetermined locations of the dropping mother machine, and a reflected beam of the two beams is detected by the measuring machine. The difference between the coordinates of the point at which the reflected beam is detected and the coordinates of the point at which the reflected beam is to be detected is to maintain the parallel flight between the dropped base unit and the measuring machine. Control method. 4. A single beam is emitted from a predetermined location of the measuring machine toward two predetermined locations of the dropping mother machine, and a reflected beam of the two beams is converted into a predetermined beam of the measuring machine. Detected at two predetermined points, by the difference between the coordinates of the point where the reflected beam is detected and the coordinates of the point where the reflected beam is to be detected, the dropping mother machine characterized by keeping the interval between the dropper and the measuring machine How to control the relative coordinates of the measuring machine.