JP2897685B2 - Command receiver for artificial satellite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a command receiver for an artificial satellite which receives a control command signal for the artificial satellite.

[0002]

2. Description of the Related Art In a conventional artificial satellite, when a command signal frequency used during launching or anomaly is different from a command signal frequency used in a steady orbit, a command receiver dedicated to each frequency is mounted.

[0003] Referring to FIG. 2, in the conventional command receiver for mounting on a satellite, a command signal for a steady orbit received by an antenna unit (not shown) is combined with a command signal for an abnormal time by a frequency conversion unit 1. Converted to the same frequency,
The command signal demodulated by the reception / demodulation unit 2 is supplied to a command decoding device (not shown). The command signal for abnormal launching is demodulated by the reception / demodulation unit 5 and the demodulated command signal is demodulated. Is supplied to a command decoding device (not shown).

[0004]

In a conventional command receiver, when frequency interference is constantly present, it is necessary to normally turn off the power so that the command receiver for an abnormal situation does not malfunction. It had been. That is, referring to FIG. 2, the power-off and power-on of the reception / demodulation unit 5 for the command signal for abnormal time is controlled by an external power on / off control signal.

In this case, if the command signal for the normal orbit is interrupted for some reason, the power of the command receiver for abnormal time (the receiving / demodulating unit 5 in FIG. 2) is automatically turned on by some means. Therefore, there is a problem that the control at the time of abnormality becomes complicated or the reliability of the satellite decreases.

Further, in the above-mentioned conventional command receiver, it is necessary to prepare respective command receivers (reception / demodulation units 2 and 5) for a stationary orbit and for an abnormal time, so that the weight becomes large. There was a problem.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems. In a command receiver for receiving a control signal to an artificial satellite, a command signal is switched when a command signal of a plurality of frequencies is used and frequency interference exists. And a command receiver that can withstand frequency interference.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a command receiver mounted on an artificial satellite, which comprises a plurality of command signals for a launch or an abnormal event and command signals used in a normal orbit. It is provided with one receiving / demodulating unit for the frequency, and automatically switches to a state of waiting for the command signal for the launch or abnormal time when detecting a disconnection state of the command signal used in the steady orbit. And a command receiver for mounting on a satellite.

The present invention preferably provides a frequency converter for inputting a command signal used in a steady orbit and converting the frequency to a predetermined intermediate frequency, and a variable signal for inputting and variably attenuating a command signal used at the time of launch or abnormality. Type attenuator,
A signal output from the frequency conversion unit is input and the signal level is detected, a level detector that detects the presence or absence of a command signal for a steady orbit and controls the amount of attenuation of the variable attenuator, from the frequency conversion unit A multiplexer that combines the output signal and the signal output from the variable attenuator; and a reception / demodulation unit that receives the output of the multiplexer as an input. Is transmitted to a command decoding device.

[0010] In the present invention, preferably, the frequency conversion unit receives a command signal used in the stationary orbit and converts the frequency to the same frequency as the frequency of the command signal used at the time of the launch or an abnormality. And

In the present invention, preferably, the variable attenuator maximizes the amount of attenuation when the command for the stationary orbit is present, and eliminates the attenuation when the command signal for the stationary orbit is cut off. It is characterized by being controlled.

[0012]

According to the present invention, a frequency converter for converting a plurality of command signal frequencies into a common IF signal using a frequency converter and receiving and demodulating the IF signal with a common receiver is provided. It has a variable attenuator to cut off the input and a level detector to detect that the command signal for the steady orbit is normally received. The output of this level detector is controlled by the variable attenuator. When the command signal for the normal orbit is interrupted (in the case of an abnormality), the frequency of the command signal for the abnormal time is set to a standby state. Can be received and demodulated in common, and the standby of these signals can be controlled in the device, so that control at the time of abnormality becomes simple,
The reliability can be greatly improved and the weight can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the configuration of an embodiment of the present invention.

Referring to FIG. 1, a command signal for a stationary orbit is converted to the same frequency as that of the command signal for an abnormal condition by frequency conversion section 1, output as an IF signal, and received by reception / demodulation section 2, The signal is demodulated and sent as a digital signal to a command decoding device (command decoder) (not shown).

The IF signal output from the frequency conversion unit 1 is simultaneously input to a level detector 4, which detects the presence or absence of a command signal for a steady orbit by performing level detection.
When there is a command for a steady orbit, control is performed so that the attenuation of the variable attenuator 3 is maximized. Thus, at the time of launch, the interference wave coming from the input side of the command signal for abnormal time is cut off.

On the other hand, if the command signal for steady orbit is interrupted due to some cause (for example, the attitude of the satellite becomes abnormal and the antenna of the satellite is shifted from the ground station direction),
The level detector 4 detects that there is no command signal for a steady orbit, and controls the variable attenuator 3 to eliminate the attenuation.

As a result, the apparatus enters a state of waiting for an abnormal time command signal. When the abnormal time command signal is input, the signal passes through the variable attenuator 3 and the hybrid (multiplexer) 6 to the receiving / demodulating unit 2. The command signal for abnormal time is input, and the command signal can be received and demodulated and output.

In the event of an abnormality, the occurrence of an interference wave is eliminated (the output of the signal source of the interference wave must be stopped due to the abnormality of the satellite), so that only the command signal for the time of the abnormality can be received.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited only to the above embodiments.
Needless to say, various modes according to the principle of the present invention are included.

[0020]

As described above, according to the present invention,
It is possible to receive and demodulate multiple command signals for a normal orbit and for an abnormal condition in common, and to control the standby of these signals in the device, simplifying control in abnormal conditions and greatly improving reliability. This has the effect of improving the weight and reducing the weight. The above-described effects can be suitably exerted in the same manner by the preferred embodiments described in the present invention (claims 2 to 4).

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frequency conversion part 2 Reception demodulation part 3 Variable attenuator 4 Level detector 5 Reception demodulation part (at the time of launch and abnormal time) 6 Hybrid (combiner)

Claims (3)

(57) [Claims] A frequency converter for inputting a command signal used in a stationary orbit and converting the frequency to a predetermined intermediate frequency; a variable attenuator for inputting a command signal used during launch or an abnormal state to variably attenuate the command signal; A signal output from the frequency converter is input and the signal level is detected, a level detector that detects the presence or absence of a command signal for a steady orbit and controls the amount of attenuation of the variable attenuator, and from the frequency converter. A multiplexer that combines the output signal and the signal output from the variable attenuator; and a reception / demodulation unit that receives the output of the multiplexer as an input. The output of the reception / demodulation unit Is transmitted to a command decoding device. Wherein said frequency converter is, according to claim 1, wherein the frequency conversion to the same frequency as the frequency of the command signal used at the time of or abnormal enter the command signal the launch used by the stationary raceway Command receiver for onboard satellites. 3. The variable attenuator is controlled so as to maximize the amount of attenuation when the command for a stationary orbit is present, and to eliminate attenuation when the command signal for a stationary orbit is cut off. The command receiver for mounting on an artificial satellite according to claim 1 .