JP2909090B2 - Light beam tracking controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention is used, for example, in an optical communication device mounted on an artificial satellite, and captures and tracks a light beam from a partner station and moves toward the partner station. The present invention relates to a light beam capture and tracking control device for controlling pointing.

(Prior Art) Conventionally, in an optical communication device mounted on an artificial satellite, a light beam capture and tracking control device as shown in FIG. 2 is used. This device uses the angle sensor 2
And a compensator (P) 31 and a differential compensator (D) constituting the first PID (proportional / integral / derivative) controller 3
The control angle is input to the integration compensator 32 and the integration compensator (I) 33 to determine the respective control values.
To control the angle of the mirror 1 to a set value by driving the mirror 1 through the control loop. Also,
Optical communication light beam 5 from the partner station reflected by mirror 1
Is incident on the optical system sensor 6 to detect the optical axis deviation, and a proportional compensator (P) 8 constituting the second PID controller 8
1. The detection shift amount is input to the integral compensator (D) 82 and the integral compensator (I) 83 to determine each control value, and according to the addition output of each control value by the adder 84, the changeover switch 9 and A tracking control loop for controlling the output signal of the optical system sensor 6 to be “0” by driving the mirror 1 via the mirror driving circuit 4 is provided.

By the way, in the conventional light beam capture and tracking control device having the above-described configuration, the mirror 1 is angle-controlled in the initial state, and after the light beam 5 enters the optical system sensor 6, the tracking control using the optical system sensor is performed by the changeover switch 9. It is common to switch to a loop. However, a disturbance torque always acts on the mirror 1, and a signal that balances the disturbance torque is held in the integration compensator 33 of the first PID controller 3 when controlling the angle of the mirror 1. On the other hand, when the angle control of the mirror 1 is switched to the tracking control loop using the optical system sensor, since the integration compensator 83 of the second PID controller 8 is zero, the compensator 83 has the mirror 1
It takes time to maintain a signal that is balanced with the disturbance torque acting on. Therefore, the mirror 1 is driven by the disturbance torque, and the light beam 5 is deviated from the field of view of the optical system sensor 6, so that the capture and tracking control may not operate normally. Further, since the integral compensator is shared, there is no room for selecting the effect of the integral compensator for each of the acquisition control loop and the tracking control loop, and it has been impossible to optimally design each loop.

(Problems to be Solved by the Invention) As described above, in the conventional light beam capture and tracking control apparatus, when switching from mirror angle control (capture control) to tracking control using an optical system sensor, the light beam is controlled by the optical system. In some cases, capture and tracking could not be performed due to deviation from the field of view of the sensor. Further, since the integral compensator is shared, there is no room for selecting the effect of the integral compensator for each of the acquisition control loop and the tracking control loop, and it has been impossible to optimally design each loop.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and ensures that the light beam does not deviate from the field of view of the optical sensor when switching from the capture control to the tracking control, thereby reliably capturing the light beam from the partner station. It is an object of the present invention to provide a light beam capture and tracking control device that can track and can optimally design integral compensation in each loop.

[Configuration of the Invention] (Means for Solving the Problems) In order to set the above object, a light beam capturing and tracking apparatus according to the present invention detects an angle of a mirror for guiding a light beam to a light receiving element with an angle sensor. A capture control loop that drives and controls the angle of the mirror so that the detection angle of the angle sensor becomes a set value and captures the light beam; and the light beam reflected by the mirror is incident on an optical sensor to emit light. A tracking control loop that detects the axis shift, drives and controls the angle of the mirror so as to eliminate the shift amount, and tracks the light beam, after capturing the light beam by the capture control loop, A light beam capturing and tracking device comprising: a loop switching unit that switches between an output of the angle detection sensor and an output of the optical system sensor. A sensor output switching unit that is provided in common with the acquisition control loop and the tracking control loop, and integrates a sensor output derived from the sensor output switching unit to add disturbance to the mirror in each control loop. An integral compensator for obtaining a torque correction signal and providing disturbance compensation in each control loop, and individually adjusting the gain of each sensor output input to the integral compensator before and after control loop switching by the loop switching means. Gain control means, wherein when the control loop is switched by the loop switching means, a disturbance torque correction signal generated by the integration compensator is continuously held, and integration of the capture control loop and the tracking control loop is performed. It is characterized in that the compensation gains are set independently of each other.

(Operation) In the light beam capture and tracking control device having the above configuration, each output of the angle detection sensor and the optical system sensor can be selected according to the switching of the control loop, and each control loop uses an integral compensator in common. By inputting the selected sensor output to the integral compensator, the correction signal of the disturbance torque to the mirror generated by the integral compensator when the control loop is switched is continuously held. Since the gain of each sensor output input to the integral compensator is individually adjusted before and after switching, compensation for the disturbance torque of the mirror is maintained when the loop is switched, so that the light beam does not deviate from the field of view, Can be set.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. However, in FIG. 1, the same parts as those in FIG. 2 are denoted by the same reference numerals, and different parts will be described here.

FIG. 1 shows the configuration, and 10 is an integral compensator sharing the integral compensators 33 and 83 of the first and second PID controllers 3 and 8. That is, the first PID controller 3 includes the proportional compensator 31 and the differential compensator 32 with the integral compensator.
10 and the second PID controller 8
Is also configured by adding the integral compensator 10 to the proportional compensator 81 and the differential compensator 82. Proportional compensator 31, 81 for each controller 3, 8
And the outputs of the differential compensators 32 and 82 are the adders 34 and 82, respectively.
After the addition at 84, the signal is selectively sent to the adder 11 by the changeover switch 9. On the other hand, the output (A side) of the angle sensor 2 and the output (B side) of the optical system sensor 6 are selected via the gain adjusters 13 and 14 by the changeover switch 12 interlocking with the switch 9 in the integration compensator 10. The output of the integral compensation value is added to the proportional compensation value and the differential compensation value by the adder 11 and sent to the mirror drive circuit 4. The gain adjusters 13 and 14 respectively control the capture control loop during loop switching,
This is for adjusting the gain of the integration compensator 10 so as to conform to the tracking control loop.

That is, in the control device having the above configuration, the switches 9 and 12 are connected to the A side during the operation of the capture control loop, and the output of the angle sensor 2 is guided to the integral compensator 10 to divide the integral compensation value for angle control. The compensation value is output by the adder 11 to the proportional compensator.
The value is added to each compensation value from 31 and the differential compensator 32. As a result, the angle control value can be obtained by the same method as in the related art, and the angle of the mirror 1 can be controlled to the set value. During the operation of the tracking control loop, the switches 9 and 12 are connected to the B side, and the output of the optical system sensor 6 is led to the integration compensator 10 to determine an integration compensation value for tracking control. 11 with proportional compensator
It adds to each compensation value from 81 and the differential compensator 82. As a result, a tracking control value similar to that of the related art is obtained, and the driving of the mirror 1 can be controlled so that the output signal of the optical system sensor 6 becomes “0”.

Here, even when switching from the capture control loop to the tracking control loop, since the integral compensator is shared, the integral compensator 10 continuously holds a signal for canceling or correcting disturbance torque acting on the mirror 1. Therefore, there is no change in the mirror angle due to disturbance torque at the time of switching. Therefore, there is no mismatch due to the switching of the integral compensation, and no switching transient occurs. Therefore, it is possible to prevent the light beam from deviating from the field of view of the optical system sensor when the loop is switched.

By the way, when the integral compensator 33 for compensating the disturbance torque acting on the mirror 1 is shared by the acquisition control loop and the tracking loop to prevent a control transient due to discontinuity of the value of the integral compensator at the time of switching, the PID controller 31,32,10
U = K _P x + K _D x + K _I ∫xdt (1) u: output of adder 11 x: output of angle sensor 2 K _P : gain of proportional compensator 31 K _D : gain of differential compensator 32 _I : Gain of the integral compensator 10 On the other hand, the controllers 81, 82, 33 of the tracking control loop
U = K _P ′ y + K _D ′ y + K _I ∫ydt (2) u: output of adder 11 y: output of optical system sensor 6 K _P ′: gain of proportional compensator 81 K _D ′: differential compensation Gain K _{I of the} compensator 82: the gain of the integral compensator 10.

Generally, the response speeds of the acquisition control loop and the tracking loop are different, so that the proportional, differential, and integral compensation gains of each loop must be set. As can be seen from the equations (1) and (2), When the integral compensator is shared, the gain K _I is naturally shared, so that an optimal integral compensator cannot be set for each loop.

Therefore, in the above apparatus, the output of the angle sensor 2 and the output of the optical system sensor 6 are sent to the integral compensator 10 via the gain adjusters 13 and 14, respectively. According to the above configuration, the controller output (adder) during the operation of the acquisition control loop
11) is: u = K _P x + K _D x + K ₁ K _I ∫xdt (3) u: output of adder 11 x: output of angle sensor 2 K _P : gain of proportional compensator 31 K _D : differentiation The gain K _I of the compensator 32: the gain K ₁ of the integral compensator 10: the gain of the gain adjuster 13. On the other hand, the controller output (output of the adder 11) during the tracking control loop operation is as follows: u = K _P ′ y + K _D ′ y + K ₂ K _I ∫ydt (4) u: Output of the adder 11 y: Optical sensor 6 Output K _P ′: gain of proportional compensator 81 K _D ′: gain of differential compensator 82 K _I : gain of integral compensator 33 K ₂ : gain of gain adjuster 14

Therefore, the optical beam capture and tracking control device having the above configuration can set each gain K ₁ and K ₂ of the gain adjusters 13 and 14 appropriately, as can be seen from the expressions (3) and (4). The integral compensation of the control loop can be appropriately set for each loop.

In the above description, PID control is assumed, but the present invention can be generally applied to a controller using an integral compensator (for example, PI control).

[Effects of the Invention] As described above, according to the present invention, the light beam does not deviate from the field of view of the optical system sensor when switching from the capture control to the tracking control, and the light beam is reliably captured and tracked from the partner station. Thus, it is possible to provide a light beam capture and tracking control device capable of optimally designing integral compensation in each loop.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a light beam capture and tracking control device according to the present invention, and FIG. 2 is a block diagram showing a configuration of a conventional light beam capture and tracking control device. 1 ... Mirror, 2 ... Angle sensor, 3,8 ... PID controller, 31,81 ... Proportional compensator, 32,82 ... Differential compensator, 3
3,83,10 …… Integral compensator, 4 …… Mirror drive circuit, 5…
... Light beam, 6 ... Optical sensor, 9,12 ... Switch, 13,14 ... Gain adjuster.

Claims (1)

(57) [Claims] An angle sensor detects the angle of a mirror for guiding a light beam to a light receiving element, and controls the angle of the mirror so that the angle detected by the angle sensor becomes a set value to capture the light beam. An acquisition control loop, and the optical beam reflected by the mirror is incident on an optical system sensor to detect an optical axis shift, and the angle of the mirror is drive-controlled so that the shift amount is eliminated, thereby tracking the light beam. A light beam capturing and tracking device, comprising: a tracking control loop for performing the tracking control loop; and a loop switching means for switching to the tracking control loop after capturing the light beam by the capture control loop. A sensor output switching unit that selectively derives an output of a sensor and an output of the optical system sensor, and is provided commonly to the acquisition control loop and the tracking control loop, An integration compensator that obtains a correction signal of disturbance torque applied to the mirror in each control loop by integrating the sensor output derived from the sensor output switching means, and provides for a disturbance compensation in each control loop; Means for individually adjusting the gain of each sensor output input to the integral compensator before and after the control loop is switched by the means, and the control means switches the control loop by the loop switching means. A light beam acquisition and tracking device, wherein the generated disturbance torque correction signal is continuously held, and the integral compensation gains of the acquisition control loop and the tracking control loop are set independently of each other.