JP2969922B2 - Antenna pointing control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an antenna pointing control device, and more particularly to an antenna pointing control device suitable for pointing control of a satellite-mounted antenna.

(Prior Art) In directivity control of an antenna mounted on a satellite, for example, as shown in FIG. 4, a sum signal and a pair of difference signals are formed from a received radio wave, and a difference between a radio wave arrival direction and an antenna directivity direction is determined from the difference signal. An error signal indicating an angle difference is formed, and a method of driving the antenna system so that the error signal becomes zero is adopted. However, since the reflecting mirror and the feeding system are conventionally driven integrally, FIG. As shown in (a), the peak position of the sum signal always coincides with the null position of the difference signal.

That is, in the related art, if the antenna system is driven so that the error signal becomes zero, the antenna is directed to the null position of the difference signal, and the capture and tracking can be performed at the peak position of the sum signal. .

Note that the difference signal is formed in two orthogonal directions corresponding to two directions of the azimuth direction and the elevation angle direction in the ground system.

(Problems to be Solved by the Invention) In the conventional antenna pointing control method described above, if an offset occurs in the error signal itself due to the characteristics of the circuit that forms the error signal, even if the error signal is set to zero, the antenna is null. Point to a position shifted from the position. As a result, acquisition and tracking are performed at positions deviating from the peak position of the sum signal, and there is a problem that the gain in the direction in which acquisition and tracking is to be performed is reduced.

In addition, when the reflector and the power supply system are not driven integrally because of a demand for weight reduction, only the reflector (the main reflector when the sub-reflector is provided) is driven. Will be driven. Then, as shown in FIG. 4 (b), the null position of the difference signal is shifted with respect to the peak position of the sum signal, and even if there is no offset in the error signal itself, from the peak position of the sum signal, as described above. A problem arises in that the capture / tracking is performed at a deviated position.

An object of the present invention is to correct an offset of an error signal itself, and further, an offset in a directing angle direction caused by a shift of a null position of a difference signal with respect to a peak position of a sum signal, and always direct the antenna to a peak position of the sum signal. An object of the present invention is to provide an antenna pointing control device which can be obtained.

(Means for Solving the Problems) In order to achieve the above object, the antenna pointing control device of the present invention has the following configuration.

That is, the antenna pointing control device of the first invention forms a difference signal in two directions orthogonal to the sum signal from a radio wave received by the reflecting mirror type aperture antenna, and calculates the difference between the radio wave arrival direction and the antenna pointing direction from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms an error signal indicating an angle difference and integrally drives a reflecting mirror and a feed system so that the error signal becomes zero; A storage unit configured as a table; and a unit configured to search the table for a correction amount corresponding to the antenna directional angle at that time for the formed error signal and correct the offset. Is what you do.

An antenna pointing control device according to a second aspect of the present invention forms a difference signal in two directions orthogonal to a sum signal from a radio wave received by a reflector type aperture antenna, and calculates an angle difference between a radio wave arrival direction and an antenna pointing direction from the difference signal. An antenna pointing control device for an antenna mounted on a satellite, which forms an error signal indicating the following, and integrally drives the reflecting mirror and the feed system so that the error signal becomes zero; A storage means in which a correction polynomial in which each of the following coefficients is determined from the relationship is set in advance; and a correction amount is calculated by substituting the antenna directivity angle at that time for the formed error signal into the correction polynomial to correct the offset. And means for performing.

Further, the antenna pointing control device of the third invention forms a difference signal in two directions orthogonal to the sum signal from a radio wave received by the reflecting mirror type aperture antenna, and calculates the difference between the radio wave arrival direction and the antenna pointing direction from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms an error signal indicating an angle difference and drives only a reflecting mirror (a main reflecting mirror if having a sub-reflecting mirror) around its focal point so that the error signal becomes zero. The antenna pointing control device includes a storage unit in which a correction amount for the offset amount of the error signal is tabulated and set in advance; and a correction amount corresponding to the antenna pointing angle at that time for the formed error signal. Means for retrieving the offset from the table and correcting the offset.

Further, the antenna pointing control device of the fourth invention forms a difference signal in two directions orthogonal to the sum signal from a radio wave received by the reflecting mirror type aperture antenna, and calculates a difference between the radio wave arrival direction and the antenna pointing direction from the difference signal. Forming an error signal indicative of the angle difference;
An antenna pointing control device for a satellite-mounted antenna that drives only a reflecting mirror (main reflecting mirror in the case of having a sub-reflecting mirror) around its focal point so that an error signal becomes zero;
The antenna pointing control device includes a storage unit in which a correction polynomial in which each coefficient is determined in advance from the relationship between the pointing angle of the antenna and the offset amount of the error signal is set in advance; Means for calculating a correction amount by substituting a directivity angle into the correction polynomial and correcting the offset.

(Operation) Next, the operation of the antenna pointing control device of the present invention configured as described above will be described.

In the first and third aspects, the offset amount of the error signal is measured in advance, and the correction amount for the offset amount is tabulated and set in the storage unit. Then, in the actual pointing control, a correction amount corresponding to the antenna pointing angle at that time is retrieved from the table for the formed error signal, the offset is corrected, and the control amount is calculated based thereon.

Further, in the second and fourth inventions, a correction polynomial is determined in advance by performing a polynomial approximation as a function of the directivity angle of the antenna with respect to the correction amount of the error signal from the relationship between the directivity angle of the antenna and the error signal, and set in the storage means. Keep it. Then, in actual pointing control, the correction amount is calculated by substituting the antenna pointing angle into the correction polynomial, the offset is corrected, and the control amount is calculated based thereon.

As a result, even if the error signal itself has an offset, the difference with respect to the peak position of the sum signal generated when the reflector of the aperture antenna (the main reflector in the case of having the sub-reflector) is driven around the focal point. The antenna can always be pointed at the peak position of the sum signal even if there is an offset in the pointing angle direction due to the shift of the null position of the signal.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an antenna pointing control apparatus according to one embodiment of the present invention. In FIG. 1, the antenna 1 is a reflecting mirror type aperture surface antenna, and includes a driving type (conventional type) for integrally driving a reflecting mirror and a power supply system, and a reflecting mirror (a sub-reflecting mirror). In this case, the driving method is a driving method in which only the main reflecting mirror is driven with its focus at the center (this is a type to which the present invention is directed).

The signal received by the antenna 1 is input to the RF sensor 2. The RF sensor 2 forms a pair of difference signals in two directions orthogonal to the sum signal from the input signal, and the tracking receiver 3
Output to As described above, the relationship between the sum signal and the difference signal is as shown in FIG. The tracking receiver 3 forms an error signal indicating an angle difference between the radio wave arrival direction and the antenna directivity direction from the difference signal, and outputs the error signal to the control circuit 6. on the other hand,
The angle encoder 4 detects an actual directional angle of the antenna 1 and outputs the detected angle to the control circuit 6. The control circuit 6 controls the drive of the motor 5 based on the two inputs and controls the directivity of the antenna 1. The above is the same as the conventional device, but the control algorithm of the control circuit 6 is different in the present invention. Hereinafter, the portion according to the present invention will be described in detail.

The control circuit 6 includes a CPU (central processing unit) 61 and a memory 62
, An encoder interface (I / F) 63, and a motor driver 64, and the control algorithm is as shown in FIG. 2 and FIG.

FIG. 2 shows a control algorithm according to the first embodiment.
In the first embodiment, the offset amount of the error signal output from the tracking receiver 3 with respect to the directional angle of the antenna 1 is measured in advance, and the correction amount for the offset amount is set in the memory 62 as an offset table.

Then, the CPU 61 reads the directivity angle of the antenna as the output of the angle encoder 4 via the encoder I / F 63 and reads the pixel signal as the output of the tracking receiver 3 (step 21). The correction amount corresponding to the directivity angle of the antenna 1 is searched from the table set in the memory 62 to correct the offset (step 22), and the control amount is calculated based on the correction based on the correction (step 23). ), And outputs a motor drive signal to the motor 5 via the motor driver 64 (step 24).

This enables acquisition and tracking at the peak position of the sum signal.

Next, FIG. 3 shows a control algorithm according to the second embodiment. In the second embodiment, from the relationship between the directional angle of the antenna 1 and the error signal, a correction polynomial is determined by performing a polynomial approximation as a function of the directional angle of the antenna 1 with respect to the correction amount of the error signal in advance and storing the correction polynomial in the memory 62. It has been set.

Then, the CPU 61 reads the directivity angle of the antenna which is the output of the angle encoder 4 via the encoder I / F 63 and reads the error signal which is the output of the tracking receiver 3 (step 21), and reads the correction polynomial from the memory 62. ,
For the error signal, the directivity angle of the antenna 1 at that time is substituted into a correction polynomial to calculate a correction amount and correct the offset (step 32), and based on this, a control law calculation is performed to calculate a control amount (step 32). 23), and outputs a motor drive signal to the motor 5 via the motor driver 64 (step 24).

This enables acquisition and tracking at the peak position of the sum signal as in the first embodiment.

When the offset correction amount is changed, it is sufficient to change each coefficient of the correction polynomial, which can be done in a short time. In this respect, in the first embodiment, the table is rewritten, and there is a disadvantage that the speed is lacking.

Further, in the first embodiment, when the accuracy of the correction of the offset of the directional angle is to be improved, the amount of data to be held in the memory becomes very large, and the time required for the search becomes long. In this respect, in the second embodiment, since the correction polynomial is used to calculate the correction amount of the offset of the directivity angle, the required memory amount can be reduced, and the time required for the offset correction can be shortened.

(Effects of the Invention) As described above, according to the antenna pointing control apparatus of the present invention, the table of the correction amount for the offset of the error signal is set in advance (the first invention and the third invention), or the antenna pointing A correction polynomial indicating the relationship between the angle and the offset amount of the error signal is set in advance (second and fourth inventions), and the offset can be corrected. Even if the error signal itself has an offset (first invention and second invention), only the reflecting mirror (or the main reflecting mirror if it has a sub-reflecting mirror) is driven around its focal point. Even if there is an offset in the directional angle direction due to the shift of the null position of the difference signal with respect to the peak position of the sum signal (third invention and fourth invention), the antenna always outputs the sum signal. There is an effect that it can be directed to the peak position.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an antenna pointing control device according to one embodiment of the present invention, FIG. 2 is a diagram showing a control algorithm according to the first embodiment of the present invention, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a diagram illustrating a control algorithm according to an example, and FIG. 4 is a diagram illustrating a relationship between an antenna driving format and a sum signal / difference signal. 1 ... antenna, 2 ... RF sensor, 3 ... tracking receiver,
4 ... Angular encoder, 5 ... Motor, 6 ... Control circuit, 61 ... CPU, 62 ... Memory.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 3/00-3/74 H01Q 3/00-3/20

Claims (4)

(57) [Claims] 1. A difference signal in two directions orthogonal to a sum signal is formed from a radio wave received by a reflector type aperture antenna, and an error signal indicating an angle difference between a radio wave arrival direction and an antenna directivity direction is formed from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms and drives a reflecting mirror and a feed system integrally so that an error signal becomes zero; a correction amount for an offset amount of an error signal is set in a table in advance and set. An antenna pointing control device comprising: a storage unit; and a unit that searches the table for a correction amount corresponding to the antenna pointing angle at that time for the formed error signal and corrects the offset. 2. A method of forming a difference signal in two directions orthogonal to a sum signal from a radio wave received by a reflector type aperture antenna, and forming an error signal indicating an angle difference between a radio wave arrival direction and an antenna directivity direction from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms and drives a reflecting mirror and a feed system integrally so that the error signal becomes zero; from the relationship between the antenna pointing angle and the offset amount of the error signal, Storage means for presetting a correction polynomial for which a coefficient has been determined; and means for correcting the offset by substituting the antenna directional angle at that time for the formed error signal into the correction polynomial to calculate a correction amount. An antenna pointing control device, comprising: 3. A difference signal in two directions orthogonal to the sum signal is formed from a radio wave received by a reflector type aperture antenna, and an error signal indicating an angle difference between a radio wave arrival direction and an antenna directivity direction is formed from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms and drives only a reflecting mirror (main reflecting mirror in the case of having a sub-reflecting mirror) around its focal point so that an error signal becomes zero; A control unit configured to store a correction amount corresponding to an offset amount of the error signal in a table, and to set the correction amount corresponding to the antenna directivity angle at that time for the formed error signal; Means for compensating for;
An antenna pointing control device comprising: 4. A difference signal in two directions orthogonal to a sum signal is formed from a radio wave received by a reflector type aperture antenna, and an error signal indicating an angle difference between a radio wave arrival direction and an antenna directivity direction is formed from the difference signal. An antenna pointing control device for a satellite-mounted antenna that forms and drives only a reflecting mirror (main reflecting mirror in the case of having a sub-reflecting mirror) around its focal point so that an error signal becomes zero; The control device includes a storage unit in which a correction polynomial in which a coefficient of each order is determined based on a relationship between the directional angle of the antenna and the offset amount of the error signal is set in advance; Means for calculating a correction amount by substituting the correction polynomial into the correction polynomial and correcting the offset.