JPH0672399A - Optical sensor device for rendezvous - Google Patents

Abstract

PURPOSE:To determine the inclining direction of a satellite instantly and perform a quick and precise attitude control by equipping the device body concerned with an inclination sensor which consists at least of a condensative optical system and a quadridivisional element and senses the inclining direction of the satellite. CONSTITUTION:An inclination sensor is equipped with a quadridivisional element 28 in the neighborhood of the focal plane of a condensative optical system 27, and the nonsensitive zone of the element 28 is adjusted so as to be parallel with the x- and y-coodinate axes. The optical axis of this inclination sensor is arranged perpendicularly to the plane on which four sensors 16a-16d are installed. The inclination sensor is installed on a chaiser so that a light emitting diode of a target lies on the optical axis. A processing circuit comprises x-adder circuits 29, y-adder circuits 30, an x-subtracter circuit 31, and a y-subtracter circuit 32 and acquires differential signals in the x- and y-axis directions for the outputs of photo-sensing parts A-D of the quadridivisional element 28. The signals are smoothened by x- and y-smoother circuits 33, 34 and fed to a preprocessing part 22, and the sign of inclination is decided by a computer 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is one of two satellites in orbit in outer space (hereinafter called chaser).
However, the present invention relates to an optical sensor device for measuring the relative coordinate position / orientation of another satellite (hereinafter referred to as a target) to perform docking.

[0002]

2. Description of the Related Art As shown in FIGS. 6 and 7, in a conventional rendezvous docking optical sensor 1, a light source 3 and an image pickup device 4 are mounted on a chaser 2 and a target 5 has a certain pattern. It is proposed that the plurality of reflector markers 6 are arranged in a plurality.

The operation of the conventional rendezvous docking optical sensor 1 will be described. First, the chaser 2 sends out light toward the target 5. At the stage of initial capture, the coordinates of the target 5 are not exactly known to the chaser 2, so that the chaser 2 sends light to a field of view having a certain extent including the direction in which the target 5 is supposed to exist. When the target 5 is exposed to light, the reflector marker 6 attached to the target 5 reflects the light. A corner cube is usually used as the reflector marker 6, and light is efficiently reflected toward the light source. On the imager 4 of the chaser 2, an image having a deformed pattern arrangement of the plurality of reflector markers 6 generated by the relative posture is formed on the image plane. The computer 7 calculates how the arrangement pattern of the reflector markers 6 captured by the imager 4 is deformed based on the pattern when facing the docking distance, and the relative coordinate position / orientation is detected.
Then, the attitude control unit 8 of the chaser 2 is controlled so that the detected relative coordinate position / orientation becomes the optimum coordinate position / orientation for docking. The above process was repeated to perform the final docking.

The above-mentioned optical sensor device for rendezvous docking has the following problems. In order to send out the light from the chaser 2, the reflection from the main body of the target 5 to which the reflector marker 6 is attached enters as background light, and in particular, when Kapton which is a heat control material is attached to the base, Kapton is used. Since the specularly reflected light returns to the chaser 2 due to the unevenness of the surface, high-level image processing is required to distinguish it from the reflection from the reflector marker 6.
Then, in order to perform advanced image processing, the CPU of the computer 7 capable of high-speed processing is required. However, the reality is that none of these high-speed processing CPUs are reliable enough to be used for space. Therefore, a high-speed image processing must be performed by using a slow CPU, which inevitably lengthens the processing time. Since the satellite detects the relative coordinate position and attitude while moving, a method with a long processing time cannot allow a single processing failure, so the system was low in safety.

In order to solve the above-mentioned problems in the rendezvous docking optical sensor device, a method of calculating mutual coordinate positions / orientations by using a simple calculation formula without using complicated processing such as image processing. For the purpose of realizing a highly reliable method in which calculation processing can be performed at high speed and a CPU does not need to be high speed, the apparatus shown in FIGS. Japanese Patent Application 3
No. 264687 and the specification and drawings.
FIG. 5A shows a mounting portion of the scanning optical device 9 mounted on the target 5. FIG. 5B shows an arrangement of some devices mounted on the chaser 2. Four detectors 16a,
16b, 16c, and 16d are arranged at intervals of 90 ° on the circumference of a radius r.

FIG. 4A shows an optical device of the scanning optical device 9. The filament of the halogen lamp 10 is arranged on the object side focus of the collimator lens 11 to obtain a substantially parallel light flux. The light flux illuminates the knife edge 13 placed on the object side focal point of the projection lens 12 from behind, and the knife edge 13
Is partially condensed by the projection lens 12, and the filament image is formed on the image side focus of the projection lens 12,
The image 14 of the knife edge is projected at an infinite distance in outer space. A condenser lens 15 is placed on the image-side focal point of the projection lens 12, and the knife-edge image 14 forms an image when the detectors 16a, 16b, 16c, and 16d of the chaser 2 shown below are at the closest distances. The optical constant is determined so that Knife edge 13 is motor 17
Move at a constant speed by the knife edge 13
The signal is detected as a pulse signal from the linear encoder 18 and the photo interrupter 19 which are carved on the edge of, and is sent to the chaser 2 by the light emitting diode 21 via the processing circuit 20. Further, the knife edge 13 has a structure capable of alternately blocking the light flux from the orthogonal directions.

FIG. 4B shows the structure of the device mounted on the chaser 2. Four detectors 16a, 16b, 16
It has a pre-processing unit 22 and a computer 23 for processing the signals from c and 16d, and is connected to a control unit 24 which controls the attitude of the chaser according to the calculated coordinates and attitude values. On the other hand, a detector 25 for receiving the pulse signal sent from the light emitting diode 21 is prepared, and its output is input to the preprocessing unit 22.

As a result, in the apparatus, the scanning mechanism provided in the scanning optical device 9 for the target 5 sets virtual coordinates in the entire field of view. Since the scanning is performed at a constant speed, the viewing angle is equally divided by the scanning angle. Therefore, the scanning angle at the time when a certain detector of the chaser 2 detects that the knife-edge image 14 has been traversed gives the viewing angle in the scanning direction. Knife edge 13 in orthogonal scanning direction
If you get the same viewing angle by scanning with
From which coordinate, it can be seen in which direction the detector of the chaser 2 is present. A plurality of detectors 16a, 16
If b, 16c, and 16d are arranged on the body of the chaser 2 in a certain pattern, the coordinates of the respective detectors with respect to the target 5 are determined.・ It was possible to ask for a posture.

When the coordinate axes of the target 5 and the chaser 2 are defined as shown in FIG. 5, the mutual coordinate position / orientation calculation is performed by each detector 16 based on the coordinate system of the target 5.
As raw coordinate values of a, 16b, 16c, and 16d,
(X ₁ , Y ₁ ), (X ₂ , Y ₂ ), (X ₃ , Y
₃ ) and (X ₄ , Y ₄ ) are obtained, first,
The coordinate amount (X _K0 , Y _K0 ) given by the following equation is calculated. X _K0 = (X _K −X _{K + 2} ) / 2 Y _K0 = (Y _K −Y _{K + 2} ) / 2

Then, the rotation γ about the Z axis of the chaser coordinate system with respect to the target coordinate system is calculated from the following equation. tan γ = (X ₂₀ −Y ₁₀ ) / (X ₁₀ + Y ₂₀ ).

Next, the inclination ω of the detector arrangement circle with respect to the xy plane of the chaser coordinate system is calculated from the following equation as a combination with the inclination axis direction ψ.

[0012]

[Equation 1]

Cosω = A / B (1) However, A = X ₂₀ ² −X ₂₀ Y ₁₀ + X ₁₀ Y ₂₀ + Y ₂₀ ² − (X ₁₀ X ₂₀
+ Y ₁₀ Y ₂₀ ) tan ψ _P · _V B = X ₁₀ ² −X ₂₀ Y ₁₀ + X ₁₀ Y ₂₀ + Y ₁₀ ² + (X ₁₀ X ₂₀
＋ Y ₁₀ Y ₂₀ ) tan ψ _P・_V

Further, the Z coordinate of the chaser origin in the target coordinate system is calculated from the following equation. Z ₀₀ = 2r / (C _x1 + C _y1 tan ψ _P · _V ) XY coordinates of the chaser origin in the target coordinate system are calculated from the following equation.

X ₀₀ = (X ₁ + X ₃ ) / 2 Y ₀₀ = (Y ₂ + Y ₄ ) / 2

[0016]

[Problems to be Solved by the Invention] However, Japanese Patent Application No. 3-2
The optical sensor device for rendezvous docking shown in the specification of 64687 and the drawings has the following problems. It is understood that when calculating ω in the equation (1), ω can take either plus or minus value with respect to one A / B value. That is, the inclination ω of the chaser 2 with respect to the target coordinate axis Z axis can take two different values, and the result cannot be uniquely obtained. For this reason, the control device has to search around to determine the inclination ω, and thus wastes time.

The present invention has been made in order to solve such a problem, and an inclination detector for detecting the sign of the inclination ω is prepared to instantaneously determine the inclination ω. To aim.

[0018]

In the optical sensor device for rendezvous docking according to the present invention, a chaser 2 is provided with an inclination detector including at least a condensing optical system and a quadrant, and a dead zone of the quadrant is a coordinate axis of the chaser 2. x, y
And a processing circuit for obtaining a differential output in the x-axis direction and the y-axis direction from the tilt detector, the scanning optical device 9 of the target 5 or the light emitting diode 21.
Is configured to determine the tilt ω.

[0019]

In the present invention, the luminous flux from the scanning optical device 9 of the target 5 or the light emitting diode 21 is irradiated onto the four-divided element by the condensing optical system. The irradiation position of the irradiated point image changes on the four-divided element depending on whether the scanning optical device 9 or the light emitting diode 21 exists on the intersection axis of the condensing optical system. The change of the irradiation position is taken out as a differential output signal, and the sign of the slope ω is determined from the combination of positive and negative of the differential output signal.

[0020]

【Example】

Example 1. 1 and 2 show an embodiment of the present invention. FIG. 1A shows an optical configuration of the tilt detector 26. A quadrant element 28 is provided near the focal plane of the condensing optical system 27.
, And the dead zone of the quadrant 28 is adjusted so as to be parallel to the x coordinate axis and the y coordinate axis, as shown in FIG. The optical axis of the tilt detector 26 is perpendicular to the plane where the four detectors 16a, 16b, 16c, and 16d are arranged, and as shown in FIG. The tilt detector 26 is mounted on the chaser 2 so that the mounting position of the light emitting diode 21 is on the optical axis thereof. Figure 1
(B) shows a block diagram of a processing circuit of the inclination detector 26. The x adder circuits 29a and 29b, the y adder circuits 30a and 30b, the x subtracter circuit 31, and the y subtracter circuit 32 are used for the x-axis direction and the y-axis with respect to the outputs of the photosensitive portions A, B, C, D of the quadrant element 28. The differential signal in the direction is obtained, and the signal is smoothed by the x smoothing circuit 33 and the y smoothing circuit 34. The smoothed DC signal is input to the pre-processing unit 22 and converted into a form that can be easily digitally processed, and the computer 23 determines the sign of the slope ω from the positive / negative combination of the DC signals on the x-axis and the y-axis.

The condenser optical system 27 of the tilt detector 26 divides the light from the light emitting diode 21 of the target 5 into four quadrants 2.
Focus on 8. This condensed light emitting diode 21
The images are usually connected in a defocused state. When the light emitting diode 21 is located on the optical axis of the tilt detector 26, the light from the light emitting diode 21 is focused on the intersection of the dead zones of the quadrant 28. Next, when the light emitting diode 21 is located outside the optical axis of the tilt detector 26,
Since it is so-called obliquely incident light, the image of the light emitting diode 21 is not condensed on the intersection, but is condensed on a slightly distant place on the quadrant 28. In FIG. 1B, the light emitting diode 2
It shows that light is incident when 1 is located at a position deviated from the optical axis in the x-axis direction. At this time, the outputs from the photosensitive portions A, B, C, and D of the four-way dividing element 28 are guided to the adder circuits and processed. The x addition circuits 29a and 29b for detecting the shift in the x-axis direction perform the processings (A + B) and (C + D), respectively, and the y subtraction circuit 31 performs the processings (A + B)-(C + D) with this input. Since the light emitting diode 21 is a linear encoder output, it emits a pulse output. Therefore, this output signal has a pulse waveform whose average level has a positive value. In addition, y addition circuits 30a and 30b for detecting a deviation in the y-axis direction, y subtraction circuit 3
2, the processing of (A + D)-(B + C) is performed similarly. In the case of FIG. 1B, the average level has a pulse waveform having a negative value. By guiding each output signal to the x smoothing circuit 33 and the y smoothing circuit 34, the respective average levels can be taken out as output signals. This allows
It is possible to detect in which direction of the tilt detector 26 the light emitting diode 21 is located. The attitude of the chaser 2 is controlled so that each average level becomes zero, and the tilt ω during rendezvous docking is corrected. be able to. It is obvious that the above function can be realized by performing the same processing by using the light from the scanning optical device 9.

Example 2. FIG. 3 shows an embodiment in which the conventional function of the detector 25 for receiving the pulse signal sent from the light emitting diode 21 and inputting the output to the preprocessing unit 22 and the function of the inclination detector 26 are combined. The optical configuration is the same as that described above, but an adding circuit 35 is added to add the conventional function. The operation of the added circuit will be described. The outputs from the x adder circuits 29a and 29b or the y adder circuits 30a and 30b are further led to the adder circuit 35 to perform the processing of A + B + C + D. However, in FIG. 3, the y addition circuit is described as an example. This signal becomes a positive pulse signal and can have a function equivalent to that of the detector 25. This allows the conventional detector 25 to be eliminated.

[0023]

As described above, according to the present invention, by adding the tilt detector including at least the condensing optical system and the four-divided element to the optical sensor device for rendezvous docking, the tilt direction of the satellite can be instantaneously measured. Therefore, it is possible to control the posture with high accuracy in a short time.

Further, by adding a tilt detector to a function equivalent to that of the conventional detector 25 on the chaser,
The detector 25 is no longer necessary and can be realized without making a large change from the conventional configuration.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical system and a circuit showing an embodiment of a tilt detector according to the present invention.

FIG. 2 is a diagram showing an arrangement of a tilt detector according to the present invention.

FIG. 3 is a diagram showing another configuration of the processing circuit of the tilt detector according to the present invention.

FIG. 4 is a configuration diagram of a conventional optical sensor device for rendezvous docking.

FIG. 5 is a layout view of a conventional optical sensor device for rendezvous docking.

FIG. 6 is a layout view of another conventional optical sensor device for rendezvous docking.

FIG. 7 is a configuration diagram of another conventional rendezvous docking optical sensor device.

[Explanation of symbols]

 1 Optical sensor for rendezvous docking 2 Chaser 3 Light source 4 Imager 5 Target 6 Reflector marker 7 Computer 8 Attitude control unit 9 Scanning optical device 10 Halogen lamp 11 Collimator lens 12 Projection lens 13 Knife edge 14 Knife edge image 15 Condenser lens 16 Detection Device 17 Motor 18 Linear encoder 19 Photointerrupter 20 Processing circuit 21 Light emitting diode 22 Preprocessing unit 23 Computer 24 Control unit 25 Detector 26 Tilt detector 27 Condensing optical system 28 Four-division element 29 x Addition circuit 30 y Addition circuit 31 x Subtraction circuit 32 y Subtraction circuit 33 x Smoothing circuit 34 y Smoothing circuit

Claims (2)

[Claims] 1. Two satellites existing in the orbits of outer space, one satellite having a certain solid angle in outer space,
It has a light source optical system having a mechanism for scanning at a constant speed from directions orthogonal to each other, and a transmitter for transmitting the scanning speed of the light source optical system to the other satellite, and the other satellite is on a circle of a certain radius. Four detectors arranged at 90 ° intervals, a receiver for receiving the scanning speed, a pre-processing unit for shaping the output signal of the detector into a gate pulse and counting the clock pulse, A computer that calculates the relative coordinate position / orientation by performing arithmetic processing from the count data of the preprocessor, and corrects the coordinate position / orientation of the satellite to the optimum state for docking based on the calculation result of this computer. In the rendezvous docking optical sensor device including a control unit, an inclination detector for detecting the inclination direction of the satellite including at least a condensing optical system and a quadrant is provided in the other satellite. Optical sensor device for the rendezvous docking, characterized in that there was e. 2. The transmitter is composed of a light emitting diode, and the receiver comprises at least a condensing optical system, a quadrant, and an adder circuit for summing outputs from the photosensitive parts of the quadrant. 2. A tilt detector for detecting the tilt direction of a satellite including the transmitter, wherein the transmitter and the receiver are arranged at positions facing each other when docking is completed. Optical sensor device for rendezvous docking.