JPS605911B2 - Aerial automatic tracking device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic antenna tracking device.

Automatic tracking methods for automatically directing an antenna to a target (for example, an artificial satellite) include a monopulse method, a conical scan method, and a step track method. The present invention resides in an antenna tracking method that is a simpler version of the step track method. The step track method memorizes the reception level before moving the antenna and the reception level after moving the antenna by a certain step angle, and compares the respective levels.As a result, the reception level after moving the antenna is If the received level increases, move the antenna again by the determined step angle in the same direction, and if the received level decreases after moving the antenna, then move in the opposite direction, By repeating these operations, the antenna is tracked and controlled in the direction where the reception level is maximized. Therefore, compared to other methods such as conical scan, it has the advantage of higher effective gain of the antenna. FIG. 1 is a system diagram of this conventional tracking method.

For example, an incoming radio wave from an artificial satellite is received by an antenna 1, amplified by a high frequency amplifier 2, and then detected by a wave detector 3, and converted into a DC voltage by sample and hold circuits 4, 4'.
sent to. The reception levels before and after the antenna is driven by one step (a certain fixed angle) are stored in sample and hold circuits 4 and 4', and compared in comparison circuit 6 to see which level is greater. . Subsequent direction determination circuit 7
It stores the result and outputs a pulse in the direction in which the antenna should be driven. It passes through the AZ/EL switching circuit 8 and the error voltage demodulation circuit 10? given to 11. The sample and hold circuits 4 and 4', the comparison circuit 6 and the direction discrimination circuit 7 are controlled by timing pulses output from the timing pulse generation circuit 9. Generally, a position loop is required for the present tracking device.

This position loop includes angle detectors 12 and 13, error voltage demodulation circuits 10 and 11, position compensation amplifier circuits 14 and 15, drive amplifier circuits 16 and 17, motors 18 and 19, and reduction gear 20,
Consists of 21. The angle detectors 12 and 13 convert the mechanical angles of the A-axis and EL-axis of the antenna into electrical information,
The error voltage demodulation circuits 10 and 11 demodulate the electrical information and output an angular error voltage proportional to the number of pulses using the function of outputting the angular error voltage and the pulses given from the step track circuit 22. The angle error voltage is amplified in amplitude and phase by the position compensation amplifier circuits 14 and 15, and power amplified by the drive amplifier circuits 16 and 17 to drive the motors 18 and 19.The motor is outputted from the error voltage demodulation circuit. The angle error voltage caused by
Due to the wind pressure applied to the antenna or the weight of the antenna itself,
Since it is difficult to obtain an accurate step width for driving the antenna, tracking errors become large.

As described above, this tracking method requires the error voltage demodulation circuits 10 and 11 and the position compensation amplifier circuits 14 and 15, making the circuit relatively complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna tracking device that does not require the position loop required in the conventional step track system, and also to provide an antenna tracking device that uses an angle error signal to maintain stability in antenna drive control. Another object of the present invention is to provide an antenna tracking device that does not require a phase compensation amplifier circuit (position compensation amplifier circuit) and an error voltage demodulation circuit.

The present invention stabilizes the control by detecting the speed and adding it to the sample hold circuit instead of the conventional position loop, and furthermore, the antenna drive motor is controlled by a changeover switch, which simplifies the configuration of the antenna. It's on an automatic tracking device.

Therefore, the present invention has a simple system configuration and is excellent in terms of reliability, maintainability, economic efficiency, etc.

FIG. 2 is a block diagram of an embodiment of the automatic tracking device of the present invention. In the figure, 1 is an antenna, 2 is an amplifier for the received signal, 3 is a detector for the received signal, 4 is a sample-and-hold integration circuit, 5 is an adder circuit, 6 and 6' are comparison circuits, 30, 3
0' is a monostable multipipelator, 31 is an addition circuit for the output pulses of the monostable multipipelators 30 and 30'', and S
, are switches (relays) that are controlled and switched by the output of the adder circuit 31; S, ^, S, and B are the contacts of S;
Forward/reverse switching circuit that controls the rotation direction of 8 and 19, 8 is A
Motors 18 and 19 on the Z-axis side and E-reaxis side and switch S
2 and S3 are switching circuits, 34 and 35 are generators that output a voltage proportional to the motor rotation speed, 20 and 21 are reduction gears, and 36 and 37 are absolute value circuit switches S2 and S4 that make the generator output a positive voltage. is the switch S that works when driving the AZ axis.
3. S5 is a switch that operates when the EL axis is driven. 39 is a control voltage input terminal to be supplied to the motors 18 and 19.

FIG. 3 is an operational waveform diagram of FIG. 2.

Figure 3a shows a signal level diagram with respect to the antenna angle at A in Figure 2 when the antenna 1 is rotated around the target (satellite) direction.The solid line in Figure 3b is the voltage at B in Figure 2. Waveform diagram "The broken line in Figure 3b is the inverted voltage waveform of Figure 2A, and Figure 3C is the voltage waveform of the second output of the adder circuit 5.
It is a voltage waveform diagram of C of a figure. Assume that the received signal level from the antenna at point A in FIG. 2 is at point P in FIG. 3, and that the antenna is first shifted to the automatic tracking state and driven from the AZ axis at this point.

In this case, the control voltage input 39 is supplied to the AZ axis, switches S4 and S2 are activated, the motor 8 of the AZ axis is driven, and the output of the generator 34 is input. If the connection is made in the direction where the level increases, the voltage at point A in Figure 2 will gradually increase as shown in Figure 3 a, and the voltage at point B in Figure 2 will increase in the direction of increase. Immediately after transitioning to the state, the switch S is activated, and the reception level just before the antenna is driven is sampled and held by the sample-hold integrating circuit 4. After this, the sample-hold integrating circuit 4 works as a hold circuit and an integrating circuit. This output B is a voltage obtained by adding the sampled and held voltage and an integral voltage having a slope proportional to the magnitude of the absolute value of the output of the generator 34. When the voltages are added by the adding circuit 5, the voltage at point C in FIG. 2 becomes negative as shown in FIG.
When the value exceeds the value, a pulse output is generated at the output of the comparator circuit 6', and this output is pulse-shaped by the monostable multipipulator 30'. Hold the sample. These are the voltages at points B and C when the Q points in FIGS. 3b and 3c are newly sampled and held. By repeating this operation, when the reception level reaches near the maximum level, the voltage at the output point B of the sample-hold integration circuit 4 becomes larger than the increase in the reception level, and the voltage at the point C becomes as shown in Figure 3c.
It becomes a positive voltage as shown in .

When this positive voltage exceeds the set level V of the positive comparator circuit 6, a pulse is output to the output of the comparator circuit 6, and this output is pulse-shaped by the monostable multipipulator 301.
This shaped pulse passes through the adder circuit 31, drives the switch S, and newly samples and holds the reception level. Further, this shaping pulse is simultaneously supplied to the forward/reverse switching circuit 32, which drives the switch S4 to reverse the driving direction of the antenna. When this reversal operation is repeated a predetermined number of times,
The AE/EL switching circuit 8 switches the antenna from the gunwale to the EL axis. When the automatic tracking control is selected and the forward/reverse switching circuit 32 is connected in the direction of decreasing the reception level, the same operation as when the reception level is near the maximum value is performed to reverse the antenna drive motor. Therefore, after that, the forward/reverse switching circuit 32 operates in the direction of increasing the reception level, so that the operation is similar to that described above.

The serpentine axis and EL axis of the antenna are switched by the side/EL switching circuit 8, and the serpentine axis and EL axis are automatically tracked alternately, and the direction with the highest reception level is automatically tracked.

In this case, for example, if automatic tracking of the EL axis is performed first, the AZ/EL switching circuit 8 counts 2 to 4 reversal command pulses from the comparator circuit 6 and the monostable multipipelator 30 and calculates the Switch the tracking to the Earth's axis.When tracking a geostationary satellite with such an automatic tracking device, there is little need for continuous tracking, so automatic tracking is performed at predetermined time intervals, such as 18 minutes or 6G minutes. That's fine.

Although the embodiment of this invention has been described for the case of tracking local maximum values, a similar system can be applied as is when automatically tracking local minimum values by reversing the polarity of the signal system. It has a wide range of applications, including automatic balancing control devices that not only automatically track objects to targets, but also track the minimum value.

This tracking device is capable of tracking the controlled object at the maximum speed, and the switching period of normal rotation and reversal near the maximum value or the maximum value can be arbitrarily set using an analog value, and the tracking error can be relatively small. Furthermore, by employing a switching circuit such as a relay, the configuration of the tracking device can be made simple and inexpensive. Brief explanation of the drawings Figure 1 is a system diagram of the conventional step track system.
FIG. 2 is a system diagram of the automatic antenna tracking device of the present invention, and FIG. 3 is an operational level diagram of FIG. 2.

In the figure, 1... Antenna, 2... High frequency amplifier, 3... Detector, 4, 4'... Sample hold (integrator) circuit, 5... Addition circuit, 6,
6'... Comparison circuit, 7... Direction discrimination circuit, 8...
・AZ/EL switching circuit, 9... timing generation circuit, 10, 11... error voltage demodulation circuit, 12, 13...
... Angle detector, 14, 15 ... Position compensation amplifier circuit, 16, 17 ... Drive amplifier circuit, 18, 19
...Motor, 20, 21...Reduction gear, 22
...Step track circuit, 30, 30'...
・・・Monostable multipipulator, 31・・・・・・
Addition circuit, 32... Forward/reverse switching circuit, 34, 35... Generator, 36, 37... Absolute value circuit, 39...
...Control voltage input, S. ...Sample hold switch, S2, S4...AZ switch, S3, S...EL switch. Figure 1 Figure 2 Three leopard boxes

Claims (1)

[Claims] 1. Detecting an antenna having a beam-like pattern, a driving means for driving the beam-like pattern of this antenna in one direction or the opposite direction by a predetermined control signal, and speed power corresponding to the magnitude of the driving speed of this driving means. a speed detecting means, a level detecting means for outputting a received voltage corresponding to the received level received by the antenna, and a level detecting means for outputting an inverted voltage obtained by inverting the received voltage when a predetermined switching signal is input, and immediately before the switching signal disappears; holding and integrating means for holding an inverted voltage, simultaneously inputting and integrating the speed voltage, and outputting a superimposed voltage superimposed on the held voltage; switching signal forming means for forming the switching signal of a predetermined width from when the received voltage becomes larger or smaller than the received voltage; An automatic antenna tracking device comprising control signal forming means for generating.