JP3661574B2 - Reflector drive control device and reflector drive system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radio telescope that observes two or more celestial bodies and a tracking device such as an antenna, and relates to a device that drives and controls a reflector provided in the tracking device, and a drive system that includes the drive control device.
[0002]
[Prior art]
Conventional radio telescopes generally include one reflecting mirror that receives radio waves radiated from a celestial body, and a reflecting mirror drive system that directs the direction of the reflecting mirror in a target direction. The reflecting mirror drive system can displace the reflecting mirror along the azimuth direction and the elevation angle direction, and can arbitrarily change the displacement angle. With this configuration, the radio telescope can, for example, alternately track two celestial bodies that are separated from each other, or alternately track a target celestial body and a celestial body for background correction that is located away from this celestial body. Can be.
[0003]
More specifically, the reflector driving system includes a reflector driving control device and a driving device. The drive device has a motor control device, a motor, and a transmission mechanism. The reflecting mirror drive control device obtains a speed operation amount based on a command signal CMD given from an external computer, and gives a torque command amount obtained based on the speed operation amount to the motor control device. The motor control device supplies electric power corresponding to the torque command amount to the motor. The motor generates a driving force corresponding to the electric power. The driving force is transmitted to the reflecting mirror through the transmission mechanism. As a result, the reflecting mirror is displaced toward the target angular position indicated by the command signal CMD.
[0004]
FIG. 13 is a graph showing the relationship between the command signal CMD and the actual angular position REAL that is the actual angular position of the reflecting mirror. The computer gives a so-called command shape signal to the reflecting mirror drive control device as a command signal. The command shape signal indicates the temporary target angular position until it stabilizes to the final target angular position so that the reflector can be displaced without overshooting the final target angular position even once, as indicated by the alternate long and short dash line. This is a signal that instructs in small steps.
[0005]
The reflecting mirror drive control device obtains the speed operation amount in accordance with the command shape signal. The speed operation amount in this case corresponds to an amount that can avoid the occurrence of overshoot. A torque command amount corresponding to the speed operation amount is given to the motor control device. As a result, as shown by the one-dot chain line in FIG. 13, the reflecting mirror is displaced according to a relatively small speed operation amount, and is stabilized at the final target angular position.
[0006]
By the way, when the reflecting mirror is displaced to the target angular position, not the command shape signal but the step from the current angular position, which is the angular position of the reflecting mirror before switching, to the final target angular position, as indicated by a solid line in FIG. It is conceivable that the step signal that changes in the shape is used as the command signal CMD. However, when the command signal CMD is used as the step signal, overshoot may occur as shown by a two-dot chain line in FIG. 13, and eventually it takes time until the reflecting mirror is stabilized at the final target angular position. It will take. Therefore, there is a problem that the observation time of the celestial object relative to the total observation time is shortened and the observation efficiency is lowered.
[0007]
More specifically, when the step signal is given as the command signal CMD, a larger speed operation amount is required than in the case of the command shape signal. As a result, as shown by a two-dot chain line in FIG. 13, the reflecting mirror approaches the final target angular position in a shorter time than the case of the command shape signal. In other words, the reflecting mirror approaches the final target angular position vigorously.
[0008]
As a result, the reflector goes too far over the target angular position, and overshoot occurs. In this case, several overshoots may occur until the reflecting mirror converges to the target angular position, and at this time, it takes a certain amount of time to converge the reflecting mirror to the target angular position. As a result, it takes extra time Δt than the command shape signal. Therefore, in the conventional radio telescope, a command shape signal may be adopted from the viewpoint of observation efficiency as described above.
[0009]
[Problems to be solved by the invention]
However, as described above, the command shape signal instructs the target angle position in small increments, so it is necessary to frequently output the command signal CMD. Therefore, there is a demerit that the processing becomes complicated as compared with the case of the step signal.
[0010]
Further, in the drive control using the command shape signal as described above, the observation efficiency of the radio telescope is not yet sufficient, and further improvement of the observation efficiency is desired.
[0011]
Accordingly, an object of the present invention is to provide a reflecting mirror drive control device and a reflecting mirror drive system that can simplify processing and can improve observation efficiency.
[0012]
[Means for Solving the Problems]
The present invention for achieving the above object is an apparatus for controlling a driving device for driving a reflecting mirror that receives radio waves, and a receiving means for receiving a displacement instruction that changes stepwise from a current angular position to a target angular position. The position error detecting means for detecting a position error which is a difference between the target angular position indicated by the displacement instruction received by the receiving means and the actual angle position of the reflecting mirror, and the position error detecting means Determining means for determining whether or not the reflecting mirror has reached the vicinity of the target angular position based on the position error; and when the determining means determines that the reflecting mirror has not reached the vicinity of the target angular position, When the driving device is controlled so that the reflecting mirror is displaced by a one-speed operation amount, and the determining means determines that the reflecting mirror has reached the vicinity of the target angular position, the first speed Reflector with a large second speed operation amount than the operation amount is intended to include a control means for controlling the driving device to be displaced.
[0013]
The determining means determines whether or not the reflecting mirror has reached the vicinity of the target angular position by, for example, comparing and determining the position error and a predetermined determination amount. Further, the first speed manipulated variable is obtained without performing integration processing so as to avoid overshoot, for example.
[0014]
Further, the present invention provides a driving system for driving a reflecting mirror that receives radio waves, and a high-speed driving unit that transmits a driving force generated by the motor to the reflecting mirror with a relatively low gear ratio, and the motor. A low-speed drive unit that transmits the driving force to the reflecting mirror with a relatively high gear ratio, a reception unit that receives a displacement instruction that changes stepwise from the current angle position to the target angle position, and a displacement instruction that is received by the reception unit Position error detecting means for detecting a position error that is a difference between the target angle position indicated in step 1 and the actual angle position of the reflecting mirror, and the reflecting mirror is in the vicinity of the target angle position based on the position error detected by the position error detecting means. Determining means for determining whether or not the reflector has reached the target angle position, and if the determining means determines that the reflecting mirror has not reached the vicinity of the target angle position, the speed corresponding to the position error is determined. Control means for operating the high-speed drive unit according to the operation amount, and operating the low-speed drive unit according to the speed operation amount according to the position error when the determination means determines that the reflecting mirror has reached the vicinity of the target angular position. And a reflecting mirror drive control device.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0016]
Embodiment 1
FIG. 1 is a conceptual diagram showing the configuration of a radio telescope according to Embodiment 1 of the present invention. The radio telescope 1 is for tracking the celestial bodies A and B as observation targets and observing their properties, and is installed on the earth, for example. The radio telescope 1 has a reflecting mirror 2 and tracks the celestial bodies A and B by receiving radio waves radiated from the celestial bodies A and B by the reflecting mirror 2. The reception frequency is, for example, several GHz. The reflecting mirror 2 is attached to the support base 3 so that it can be displaced along the azimuth direction and the elevation angle direction. With this configuration, it is possible to track one celestial body that moves relative to the ground surface, or to track a plurality of celestial bodies alternately.
[0017]
For example, when two celestial bodies A and B are alternately tracked, when the tracking of one celestial body A is finished and the tracking of the other celestial body B is started, it is necessary to switch the direction of the reflecting mirror 2. In other words, the direction of the reflecting mirror 2 facing one celestial body A needs to be directed to the other celestial body B. On the other hand, in order to increase the observation efficiency, it is necessary to quickly switch the direction of the reflecting mirror 2 to the target direction and stabilize the state in that state.
[0018]
Therefore, in the first embodiment, the reflector 2 is displaced by the first speed operation amount that is at least the speed operation amount that can avoid the occurrence of the overshoot until reaching the vicinity of the target angle position, and reaches the vicinity of the target angle position. After that, the reflecting mirror 2 is displaced by a second speed operation amount larger than the first speed operation amount. By doing so, the reflecting mirror 2 can be stabilized at the target angular position without generating an overshoot and faster than when the reflecting mirror 2 is displaced little by little even after reaching the vicinity of the target angular position.
[0019]
FIG. 2 is a block diagram showing the internal configuration of the radio telescope 1. The radio telescope 1 includes a reflecting mirror 2, a reflecting mirror driving system 10, and a command control device 11. For example, when the direction of the reflecting mirror 2 is switched from one celestial body A to the other celestial body B, the command control device 11 gives a stepped command signal CMD corresponding to a displacement instruction to the reflecting mirror drive system 10. More specifically, the command control device 11 provides the reflecting mirror drive system 10 with a command signal CMD that changes stepwise from the current angle position to the target angle position.
[0020]
Here, the current angular position corresponds to the angular position of the reflecting mirror 2 before switching, and the target angular position corresponds to the angular position after switching. Therefore, in this case, the current angular position is an angular position at which the reflecting mirror 2 faces the celestial body A, and the target angular position is an angular position at which the reflecting mirror 2 faces the celestial body B.
[0021]
The reflecting mirror drive system 10 performs position compensation and velocity loop compensation based on the target angular position indicated by the command signal CMD and the actual angular position REAL of the reflecting mirror 2, and obtains a displacement amount by which the reflecting mirror 2 should be displaced. . Thereafter, the reflecting mirror driving system 10 generates a driving force corresponding to the obtained displacement amount, and displaces the reflecting mirror 2 with the driving force. Thereby, the direction of the reflecting mirror 2 can be quickly switched from one celestial body A to the other celestial body B.
[0022]
More specifically, the command control device 11 is constituted by a computer, for example. The command control device 11 outputs a command signal CMD to the reflecting mirror drive system 10 at regular intervals. More specifically, when switching the direction of the reflecting mirror 2 from one celestial body A to the other celestial body B, the command control device 11 changes the target corresponding to the other celestial body B from the current angular position corresponding to the one celestial body A. A command signal CMD that changes stepwise at the angular position is output.
[0023]
The reflecting mirror drive system 10 includes one reflecting mirror drive control device 20, two driving devices 30, and two angle detection devices (represented as EL (θ) and AZ (θ) in FIG. 1) 40. Yes. The reflecting mirror drive control device 20, the drive device 30, and the angle detection device 40 have a hardware configuration independent of each other. The reflecting mirror drive control device 20 controls the drive device 30 according to the command signal CMD given from the command control device 11. The driving device 30 actually displaces the reflecting mirror 2 in accordance with the control by the reflecting mirror drive control device 20. The angle detection device 40 detects an actual angular position REAL corresponding to the current angular position of the reflecting mirror 2.
[0024]
More specifically, the reflecting mirror drive control device 20 includes two drive control units 21. One of the two drive control units 21 controls the displacement along the azimuth direction of the reflecting mirror 2, and the other controls the displacement along the elevation angle direction of the reflecting mirror 2. The drive control unit 21 includes a position compensation unit 22 and a speed loop unit 23.
[0025]
The position compensation unit 22 includes a computer including a CPU (Central Processing Unit), and executes position compensation processing according to a position compensation program in software. More specifically, the position compensation unit 22 performs position compensation processing based on the command signal CMD given from the command control device 11. In the position compensation process, the magnitude of the amount of displacement by which the reflecting mirror 2 is to be displaced is controlled according to the difference between the target angular position indicated by the command signal CMD and the actual angular position REAL of the reflecting mirror 2. The displacement amount after the control is given to the speed loop unit 23 as a speed operation amount.
[0026]
The speed loop unit 23 is composed of a DSP (Digital Signal Processor) card or the like, and is for suppressing the influence of disturbance such as wind. For example, the speed loop unit 23 executes, in software, a major speed compensation process according to the major speed compensation program, a minor speed compensation process according to the minor speed compensation program, and the like. Thus, the speed loop unit 23 suppresses the influence of the disturbance from the speed operation amount given from the position compensation unit 22 and obtains the torque command amount.
[0027]
The reflecting mirror drive control device 20 outputs a torque command amount to the drive device 30. The two driving devices 30 respectively displace the reflecting mirror 2 along the azimuth direction and the elevation direction. More specifically, the drive device 30 includes a motor control unit 31, a motor (M) 32, and a transmission mechanism 33. The motor control unit 31 is composed of, for example, two sets of motor drivers. The torque command amount is input to the motor control unit 31. The motor control unit 31 supplies electric power corresponding to the torque command amount to the motor 32.
[0028]
The motor 32 generates a rotational force necessary to displace the reflecting mirror 2 in the azimuth direction according to the electric power supplied from the motor control unit 31. The rotational force generated by the motor 32 is given to the transmission mechanism 33. The transmission mechanism 33 has, for example, a plurality of gears that mesh with each other, and transmits the rotational force applied from the motor 32 to the reflecting mirror 2. Thereby, the reflecting mirror 2 can be displaced according to the torque command amount given from the reflecting mirror drive control device 20.
[0029]
The two angle detection devices 40 are provided in association with the reflecting mirror 2. The two angle detection devices 40 respectively detect the angular position in the azimuth direction of the reflecting mirror 2 and the angular position in the elevation angle direction of the reflecting mirror 2 as the actual angular position REAL. Each angle detection device 40 outputs the actual angular position REAL to the reflecting mirror drive control device 20.
[0030]
FIG. 3 is a graph for explaining the relationship between the command signal CMD and the actual angular position REAL of the reflecting mirror 2. FIG. 4 is a conceptual diagram showing the relationship in the azimuth plane between the reflecting mirror 2 and the two celestial bodies A and B, and shows a case where the direction of the reflecting mirror 2 is switched from the first celestial body A to the second celestial body B. ing. Below, the case where the direction in the azimuth | direction surface of the reflective mirror 2 is switched from the celestial body A to the celestial body B is demonstrated with reference to FIG.2, FIG.3 and FIG.4.
[0031]
The command control device 11 outputs a command signal CMD that indicates the current angle position θ1 corresponding to the celestial body A until the direction of the reflecting mirror 2 is switched. When the direction of the reflecting mirror 2 is switched to the celestial body B in this state, the command control device 11 outputs a command signal CMD that indicates the target angular position θ2 corresponding to the celestial body B. In this case, the command signal CMD has a step shape as indicated by a solid line in FIG.
[0032]
When the angular position instructed by the command signal CMD is switched from the current angular position θ1 to the target angular position θ2, the reflecting mirror drive control device 20 compares and determines the position error ERR and the first determination amount d1. The position error ERR corresponds to the difference between the target angular position θ2 and the actual angular position REAL. The first determination amount d1 is an amount corresponding to the difference between the first angular position θth1 set near the target angular position θ2 and the target angular position θ2.
[0033]
When the position error ERR is equal to or larger than the first determination amount d1, the reflecting mirror 2 has not reached the vicinity of the target angular position θ2, and therefore the reflecting mirror drive control device 20 executes a process for obtaining the first speed operation amount Δθ1. Here, the first speed manipulated variable Δθ1 is obtained without performing integration processing so as to avoid the occurrence of overshoot. The reflecting mirror drive control device 20 obtains a first torque command amount based on the first speed operation amount Δθ1, and gives this first torque command amount to the drive device 30. As a result, the reflecting mirror 2 is displaced according to the first speed operation amount Δθ1.
[0034]
Thus, the reflecting mirror 2 is displaced in small increments according to the first speed manipulated variable Δθ1 that can avoid the occurrence of overshoot until it reaches the vicinity of the target angular position θ2.
[0035]
When the position error ERR is less than the first determination amount d1, that is, when the reflecting mirror 2 reaches the vicinity of the target angular position θ2, the reflecting mirror drive system 10 causes the reflecting mirror 2 to reach the target angular position θ2 all at once. . However, when the reflecting mirror 2 is suddenly displaced, the reflecting mirror 2 has been displaced in small increments until that time, resulting in control discontinuity. Therefore, the reflector driving system 10 according to the first embodiment is configured to smoothly displace the reflector 2 by gradually increasing the gain of the position compensation unit 20 with the position error ERR.
[0036]
More specifically, when the position error ERR is less than the first determination amount d1, the reflecting mirror drive control device 20 further compares and determines the position error ERR and the second determination amount d2. The second determination amount d1 is smaller than the first determination amount d1, and is the difference between the second angular position θth2 and the target angular position θ2 set on the target angular position θ2 side with respect to the first angular position θth1. It is equivalent to.
[0037]
When the position error ERR is equal to or larger than the second determination amount d2, the reflecting mirror drive control device 20 obtains an intermediate speed operation amount Δθm that is slightly larger than the first speed operation amount Δθ1. This intermediate speed operation amount Δθm is given to the drive device 30. As a result, the reflecting mirror 2 approaches the target angular position θ2 with a larger angular width than before. More specifically, in this case, the reflecting mirror 2 is displaced so as to draw a steeper curve than before, between the points k1 and k2 in FIG.
[0038]
On the other hand, when the position error ERR is less than the second determination amount d2, the reflecting mirror drive control device 20 obtains the second speed operation amount Δθ2. The second speed manipulated variable Δθ2 is larger than the first speed manipulated variable Δθ1 and the intermediate speed manipulated variable Δθm by being cured by the position error ERR having the same magnitude. For example, the maximum value of the position error ERR corresponding to the second speed operation amount Δθ2 is an amount equal to the second determination amount d2. The reflecting mirror drive control device 20 obtains a second torque command amount based on the second speed operation amount Δθ2, and the second torque command amount is given to the drive device 30. As a result, the reflecting mirror 2 further approaches the target angular position θ2 with a larger angular width than before. That is, the reflecting mirror 2 is displaced so as to draw a steeper curve than before, such as between the point k2 and the target angular position θ2 in FIG.
[0039]
As described above, the reflecting mirror 2 is displaced in small increments until the reflecting mirror 2 reaches the vicinity of the target angular position θ2, and when the reflecting mirror 2 reaches the vicinity of the target angular position θ2, the reflecting mirror 2 is smoothly displaced. It is displaced at a stroke after. Therefore, the reflecting mirror 2 can be quickly stabilized at the target angular position θ2.
[0040]
More specifically, for example, when a command shape signal is given as the command signal CMD, the reflecting mirror 2 is stabilized at the target angular position θ2 during the settling time Δt1 in FIG. 3 (corresponding to a curve indicated by a two-dot chain line from the point k1). On the other hand, according to the first embodiment, the reflecting mirror 2 is stabilized at the target angular position θ2 at the settling time Δt2 in FIG. That is, according to the first embodiment, the settling time can be shortened by Δt1−Δt2 = Δta, compared to the case where the command shape signal is given as the command signal CMD. That is, the settling property is improved. Therefore, the observation efficiency can be improved.
[0041]
FIG. 5 is a flowchart showing the position compensation process. Hereinafter, the position compensation process described with reference to FIGS. 3 and 4 will be described in more detail. The position compensation unit 22 receives the command signal CMD output from the command control device 11 (step S1), and receives the actual angle position REAL (step S2), the target angle position θ2 indicated by these command signals CMD and A position error ERR which is a difference from the actual angular position REAL is obtained (step S3).
[0042]
Next, the position compensator 22 performs a position error ERR determination process (step S4). Specifically, the position compensation unit 22 compares and determines the position error ERR and the first determination amount d1. More specifically, the position compensation unit 22 determines whether the position error ERR is less than the first determination amount d1.
[0043]
If the position error ERR is greater than or equal to the first determination amount d1, the position compensation unit 22 performs an I-type control process (step S5). More specifically, the position compensation unit 22 obtains a first speed operation amount Δθ1 corresponding to the multiplication result by multiplying the position error ERR by a predetermined first gain ω1. In this case, the gain ω1 is set to a value that can obtain a maximum speed manipulated variable that can avoid the occurrence of overshoot when multiplied by the position error ERR.
[0044]
On the other hand, if the position error ERR is less than the first determination amount d1, then the position compensation unit 22 compares and determines the position error ERR and the second determination amount d2 (step S6). More specifically, the position compensation unit 22 determines whether the position error ERR is less than the second determination amount d2.
[0045]
If the position error ERR is not less than the second determination amount d2, the position compensation unit 22 performs an interpolation process for gradually increasing the gain (step S7). Specifically, the position compensation unit 22 obtains the intermediate speed operation amount Δθm by multiplying the position error ERR by a value obtained by dividing the intermediate gain ωm by the square root of the position error ERR. In this case, the intermediate speed manipulated variable Δθm is a speed manipulated variable that is larger than the first speed manipulated variable Δθ1 and smaller than the second speed manipulated variable Δθ2 over the position error ERR of the same magnitude, and the position error. The ERR increases as it approaches the second determination amount d2.
[0046]
On the other hand, if the position error ERR is less than the second determination amount d2, it is considered that the reflecting mirror 2 has reached the immediate vicinity of the target angular position θ2, so that the reflecting mirror 2 can reach the target angular position θ2 all at once. In addition, the position compensation unit 22 executes a type II control process (step S7). More specifically, the position compensation unit 22 multiplies the position error ERR by a predetermined second gain ω2. Thereafter, the position compensation unit 22 multiplies the multiplication result by an additional gain ωa, and further integrates the multiplication result to obtain the second speed manipulated variable Δθ2. In this case, the second gain ω2 is set to a value that is at least larger than the first gain ω1. Therefore, the second speed operation amount Δθ2 larger than the first speed operation amount Δθ1 can be obtained.
[0047]
FIG. 6 is a graph showing the gain with respect to the position error ERR. When the position error ERR is equal to or greater than the first determination amount d1, the gain is set to the first gain ω1. When the position error ERR is less than the first determination amount d1 and greater than or equal to the second determination amount d2, the gain is an intermediate gain ωm between the first gain ω1 and the second gain ω2 by the square root of the position error ERR. Set to the divided value. When the position error ERR is less than the second determination amount d2, the gain is set to the second gain ω2.
[0048]
As described above, according to the first embodiment, when the step-like command signal CMD is given, the gain is decreased until the reflecting mirror 2 reaches the vicinity of the target angular position, and the vicinity of the target angular position is reached. Sometimes the gain is increased to cause the reflecting mirror 2 to reach the target angular position all at once.
[0049]
Therefore, the reflecting mirror 2 can be stabilized more quickly at the target angular position than when the reflecting mirror 2 is displaced in small increments until the target angular position is stabilized. That is, the settling time can be shortened. For this reason, the time required for observing celestial objects can be kept longer than the total observation time. Therefore, the observation efficiency can be improved. In addition, since the command control device 11 only needs to output the command signal CMD for instructing the target angular position θ2, the processing of the command control device 11 can be simplified.
[0050]
Further, when the reflecting mirror 2 reaches the vicinity of the target angular position, the II control process including the integration process is performed on the reflecting mirror 2, so that a so-called steady-state deviation can be prevented from occurring. More specifically, for example, the celestial body B after switching may move little by little with respect to the earth. In this case, in order to observe the celestial body B, it is necessary to displace the reflecting mirror 2 in accordance with its movement. For this reason, the command control device 11 changes the target angle position according to the movement of the acquired object B once the target angle position is set to θ2. As a result, the command signal CMD may be a so-called ramp signal that gradually moves away from the current angular position θ1, as shown in FIG.
[0051]
In the case of a ramp signal, if the reflecting mirror 2 is controlled by the I-type control processing that does not include integration processing with respect to the target angular position, the reflecting mirror 2 only needs to be displaced along the change of the ramp signal as shown by the broken line. Even after passing, the target angular position is not reached. The difference between the target angular position and the actual angular position REAL of the reflecting mirror 2 in this case is referred to as a steady deviation Δσ. However, if the reflecting mirror 2 is controlled by the type II control process including the integration process as described above, the occurrence of the steady deviation Δσ can be prevented. Therefore, since the celestial body B can be observed reliably, the observation accuracy can be improved.
[0052]
Embodiment 2
FIG. 8 is a block diagram showing the configuration of the radio telescope according to Embodiment 2 of the present invention. In FIG. 8, the same reference numerals are used for the same functional parts as in FIG.
[0053]
In the first embodiment, the reflecting mirror 2 is displaced in small increments until the reflecting mirror 2 reaches the vicinity of the target angular position, and after the reflecting mirror 2 reaches the vicinity of the target angular position, the reflecting mirror 2 is displaced at a stroke. Thus, the reflecting mirror 2 is quickly stabilized at the target angular position, thereby improving the observation efficiency.
[0054]
In contrast, in the second embodiment, the reflecting mirror 2 is displaced at a relatively high speed until the reflecting mirror 2 reaches the vicinity of the target angular position, and after the reflecting mirror 2 reaches the vicinity of the target angular position, The moving time of the reflecting mirror 2 is shortened by displacing the reflecting mirror 2 at a relatively low speed, thereby improving the observation efficiency.
[0055]
More specifically, the radio telescope includes two types of motors, a low speed motor and a high speed motor, in order to realize the displacement of the reflecting mirror 2 as described above. That is, this radio telescope uses a high-speed motor to displace the reflecting mirror 2 at a relatively high speed until the reflecting mirror 2 reaches the vicinity of the target angular position, and after the reflecting mirror 2 reaches the target angular position, The reflecting mirror 2 is displaced at a relatively low speed using a low speed motor. By doing so, the moving time of the reflecting mirror 2 between the two celestial bodies A and B is shortened while avoiding overshoot.
[0056]
In addition, this radio telescope sets the backlash of the driving device 30 in advance in order to ensure tracking accuracy during astronomical tracking. Specifically, the low-speed drive device 30 used at the time of tracking employs a drive system that can ignore backlash. In other words, the low-speed drive device 30 employs an anti-backlash drive system that can ignore the play between the gears. On the other hand, the high-speed drive device 30 employs a backlash drive system having play between gears. With this configuration, the subtle rotation of the low-speed motor can be transmitted to the reflecting mirror 2 with high accuracy during tracking, and the reflecting mirror 2 can be slightly displaced. Therefore, it is possible to track a celestial body that moves little by little. Therefore, tracking accuracy can be ensured.
[0057]
More specifically, the reflector drive control device 20 according to the second embodiment includes a position compensation unit 51, a high speed speed loop unit 52, and a low speed speed loop unit 53. The position compensation unit 51 obtains a position error ERR that is the difference between the target angular position instructed by the command signal CMD and the actual angular position REAL, and uses the obtained position error ERR for a high speed and a low speed speed loop unit 52. , 53 are selectively output. The position compensation unit 51 is composed of, for example, a computer including a CPU, and realizes the selection process in software. Of course, the output switching function of the position error ERR in the position compensation unit 51 may be configured by a switching element as hardware.
[0058]
The drive device 30 includes a high speed drive unit 60 and a low speed drive unit 70. The high speed drive unit 60 includes a motor control unit 61, a single high speed motor 62, and a transmission mechanism 63. The low speed drive unit 70 includes a motor control unit 71, two low speed motors 72, and a transmission mechanism 73. Torque command amounts are given to the motor control units 61 and 71 from the high speed speed loop unit 52 and the low speed speed loop unit 53, respectively.
[0059]
The high-speed motor 62 has, for example, 2000 rpm as the rated rotation speed. More specifically, the high-speed motor 62 operates most stably at a rotational speed near the maximum rotational speed. Therefore, the transmission mechanism 63 of the high-speed drive unit 60 sets the gear ratio relatively low. That is, the transmission mechanism 63 of the high-speed drive unit 60 is configured by meshing a plurality of gears so that the gear ratio is relatively low. Thereby, the rotational force generated by the high-speed motor 62 is transmitted to the reflecting mirror 2 at a relatively low gear ratio. Therefore, the reflecting mirror 2 can be displaced at a relatively high speed. In other words, the reflecting mirror 2 can be displaced by a relatively large motor rotation amount.
[0060]
Each of the two low-speed motors 72 has, for example, 2000 rpm as the rated rotational speed. More specifically, like the high-speed motor 62, the low-speed motor 72 operates most stably in the vicinity of the maximum rotation speed. Therefore, the transmission mechanism 73 of the low-speed drive unit 70 sets the gear ratio relatively high. That is, the transmission mechanism 73 of the low-speed drive unit 70 is configured by meshing a plurality of gears so that the gear ratio is relatively high. Thereby, the rotational force generated by the low speed motor 72 is transmitted to the reflecting mirror at a relatively high gear ratio. Therefore, the reflecting mirror 2 can be displaced at a relatively low speed. In other words, the reflecting mirror 2 can be displaced with a relatively small amount of motor rotation.
[0061]
Further, the two low-speed motors 72 are controlled so as to generate a constant pre-torque along opposite directions to realize anti-backlash drive control. By generating pre-torques in opposite directions in the two low-speed motors 72, play between the gears due to the rotation of one low-speed motor is prevented by the reverse rotation of the other low-speed motor.
[0062]
FIG. 9 is a flowchart for explaining the position compensation processing in the position compensation unit 51. In the following description, it is assumed that the direction of the reflecting mirror 2 is switched from the first celestial body A to the second celestial body B.
[0063]
The position compensation unit 51 receives the step-like command signal CMD output from the command control device 11 and the actual angular position REAL output from the angle detection device 40. The position compensation unit 51 obtains a position error ERR that is the difference between the target angular position instructed by the command signal CMD and the actual angular position REAL (steps T1 to T3), and the position error ERR and a predetermined determination amount d. Are compared (step T4). Here, the determination amount d is an amount corresponding to the difference between the target angular position θ2 and the angular position θth set in the vicinity of the target angular position θ2.
[0064]
If the position error ERR is equal to or greater than the determination amount d, the reflecting mirror 2 has not yet reached the vicinity of the target angular position θ2, and therefore the position compensation unit 51 performs high-speed drive control (step T5). Specifically, the position compensation unit 51 obtains the speed operation amount Δθ by multiplying the position error ERR by a certain gain ω, and gives the obtained speed operation amount Δθ to the high speed speed loop unit 52. As a result, the speed operation amount Δθ is given to the high speed drive unit 60 as a torque command amount after the major speed compensation and the minor speed compensation are performed in the high speed speed loop unit 52. As a result, the high speed motor 62 is driven with electric power corresponding to the speed operation amount Δθ, and the driving force is transmitted to the reflecting mirror 2 with a relatively low gear ratio. Thereby, the reflecting mirror 2 is displaced at a relatively high speed.
[0065]
On the other hand, if the position error ERR is less than the determination amount d, it is considered that the reflecting mirror 1 has reached the vicinity of the target angular position CMD, and therefore the position compensation unit 51 executes the low speed drive control (step T6). More specifically, the position compensation unit 51 multiplies the position error ERR by the gain ω and then adds the multiplication result and the integration result obtained by multiplying the multiplication result by the integration gain. The speed operation amount Δθ is obtained, and then the obtained speed operation amount Δθ is given to the low speed speed loop unit 53. As a result, the speed operation amount Δθ is given to the low speed drive unit 70 as a torque command amount after major speed compensation and minor speed compensation are performed in the low speed speed loop unit. As a result, the low speed motor 72 is driven with electric power corresponding to the speed operation amount Δθ, and the driving force is transmitted to the reflecting mirror 2 with a relatively high gear ratio. Thereby, the reflecting mirror 2 is displaced at a relatively low speed. In this way, the reflecting mirror 2 can be stabilized at the target angular position θ2.
[0066]
When observing the celestial body B, the reflecting mirror 2 is driven by the low-speed drive unit 70. As described above, no backlash occurs in the low-speed drive unit 70, so the low-speed drive unit 70 can transmit the driving force to the reflecting mirror 2 with high accuracy. Therefore, a delicate movement of the reflecting mirror 2 can be realized. Therefore, even if the celestial body B moves little by little, the celestial body B can be reliably tracked.
[0067]
As described above, according to the second embodiment, the reflecting mirror 2 is moved at a relatively high speed until the vicinity of the target angular position is reached, and the reflecting mirror 2 is relatively moved after reaching the vicinity of the target angular position. Move at low speed. Therefore, the movement time of the reflecting mirror 2 between the celestial bodies can be shortened. Therefore, the observation efficiency of celestial bodies can be improved.
[0068]
This point will be described in more detail with reference to FIG. For example, when the command shape signal is used as the command signal CMD as in the prior art, the reflecting mirror 2 is displaced while drawing a locus as indicated by a two-dot chain line. On the other hand, in the second embodiment, the reflecting mirror 2 is displaced at a relatively high speed until it reaches the vicinity of the target angular position, so that the reflecting mirror 2 is displaced while drawing a locus shown by a broken line. . That is, a steep curve is drawn as compared with the case of the command shape signal.
[0069]
Here, if the reflecting mirror 2 is displaced at a high speed as it is, overshoot may occur. Therefore, in the second embodiment, after the reflecting mirror 2 reaches the vicinity of the target angular position θ2, the reflecting mirror 2 is displaced at a relatively low speed. As a result, the locus of the reflecting mirror 2 becomes gentle, and the reflecting mirror 2 is stabilized at the target angular position θ2 without overshooting the target angular position θ2. Therefore, according to the second embodiment, the settling time can be shortened by the time Δtb as compared with the case of the command shape signal. Therefore, the observation efficiency of celestial bodies can be improved.
[0070]
Embodiment 3
FIG. 11 is a conceptual diagram showing a configuration of a drive device 30 according to Embodiment 3 of the present invention. In FIG. 11, the same reference numerals are used for the same functional parts as in FIG.
[0071]
In the second embodiment, a case where the high-speed motor 62 and the low-speed motor 72 are coupled to separate transmission mechanisms 63 and 73 is taken as an example. On the other hand, in the third embodiment, a case where the high speed motor 62 and the low speed motor 72 are coupled to the common transmission mechanism 80 is taken as an example.
[0072]
More specifically, one high speed motor 62 is connected to the transmission mechanism 80 via a high speed motor shaft 62a. The two low-speed motors 72 are connected to the transmission mechanism 80 via low-speed motor shafts 72a. More specifically, the transmission mechanism 80 has a plurality of gears that mesh with each other. The high-speed motor shaft 62a and the two low-speed motor shafts 72a are connected to one of a plurality of gears of the transmission mechanism 80, and the gear 81 to which the high-speed motor shaft 62a is connected and the low-speed motor shaft 72a are connected. The gear 82 is connected directly or indirectly to one common gear.
[0073]
When driving the low speed motor 72, the gear of the transmission mechanism 80 rotates with the rotation of the two low speed motor shafts 72a. On the other hand, a high-speed motor shaft 62 a is also connected to the transmission mechanism 80. Therefore, the reflecting mirror drive control device 20 drives the high-speed motor 62 as a slave so as not to interfere with the rotation transmission of the low-speed motor 72. More specifically, in the reflecting mirror drive control device 20, the gear connected to the high-speed motor 62 has a gap less than the size of the backlash in the high-speed drive unit 60 with respect to the gear that rotates as the low-speed motor 72 rotates. The high-speed motor 62 is driven and controlled so as to rotate while leaving a gap.
[0074]
Accordingly, even when the high speed motor 62 and the low speed motor 72 are connected to the common transmission mechanism 80, the high speed motor 62 does not hinder the rotation of the low speed motor 72, so that anti-backlash drive control at the time of low speed driving is realized. Can do. That is, the transmission mechanism 80 transmits a driving force corresponding to a slight rotation of the low-speed motor shaft 72a to the reflecting mirror 2 with high accuracy.
[0075]
On the contrary, when driving the high-speed motor 62, the plurality of gears in the transmission mechanism 80 rotate as the single high-speed motor shaft 62a rotates. In this case, the two low-speed motors 72 become loads and rotate with the rotation. Therefore, it is necessary to apply a high speed motor 62 having a capacity larger than that of the low speed motor 72. The two low-speed motors 72 are controlled to generate pre-torques in opposite directions to achieve anti-backlash drive control. However, when driving the high-speed motor 62, both of these pre-torques are set to zero. .
[0076]
As described above, according to the third embodiment, when the high-speed motor 62 and the low-speed motor 72 are connected to the common transmission mechanism 80, when the low-speed drive unit 70 is driven and controlled, the high-speed motor 62 is slave-driven. Yes. Accordingly, better anti-backlash drive control can be realized during low-speed drive control. Therefore, the tracking accuracy of the celestial body can be further improved.
[0077]
Embodiment 4
FIG. 12 is a block diagram showing an overall configuration of a radio telescope 1 according to Embodiment 4 of the present invention. 12, the same reference numerals are used for the same functional parts as in FIG.
[0078]
In the second embodiment, the high-speed drive unit 60 and the low-speed drive unit 70 are selectively used to shorten the moving time between the two celestial bodies A and B of the reflecting mirror 2, thereby improving the observation efficiency. ing. On the other hand, in the third embodiment, the moving time between the two celestial bodies A and B of the reflecting mirror 2 is shortened by variably controlling the attenuation characteristic of the reflecting mirror 2, thereby improving the observation efficiency. ing.
[0079]
More specifically, the reflecting mirror driving system 10 according to the fourth embodiment includes an attenuator 90 connected to the reflecting mirror 2. In addition, the reflecting mirror driving system 10 includes an attenuator driving device 91 for driving the attenuator 90. Further, the reflecting mirror drive control device 20 includes an attenuator drive control unit 92. The attenuator drive control unit 92 controls the attenuator drive device 91.
[0080]
Further, the position compensation unit 93 in the reflecting mirror drive control device 20 obtains the difference between the target angular position instructed by the command signal CMD and the actual angular position REAL as the position error ERR, and the calculated position error ERR After multiplying by a predetermined gain ω, the speed operation amount Δθ is obtained by adding the multiplication result and the integration result obtained by multiplying the multiplication result by the integral gain, and the obtained speed operation amount Δθ is obtained as a speed loop. This is given to the unit 94. The speed loop unit 94 performs speed compensation for the speed operation amount Δθ.
[0081]
Further, the position compensation unit 93 gives the position error ERR to the attenuator drive control unit 92 when the position error ERR is obtained. Based on this position error ERR, the attenuator drive control unit 92 controls the attenuator driving device 91 according to whether or not the reflecting mirror 2 has reached the vicinity of the target angular position. More specifically, the attenuator drive control unit 91 determines whether or not the position error ERR is less than a predetermined determination amount d.
[0082]
If the position error ERR is not less than the determination amount d, the reflecting mirror 2 has not reached the vicinity of the target angle position, so the attenuator drive control unit 92 sets the attenuation characteristic of the reflecting mirror 2 to the first characteristic. The attenuator driving device 91 is controlled. Here, the first characteristic is a characteristic in which the speed operation amount of the reflecting mirror 2 is relatively large, and is a characteristic that draws a relatively steep curve on the attenuation characteristic graph. The attenuator driving device 91 operates the attenuator 90 according to the control of the attenuator drive control unit 92. As a result, the reflecting mirror 2 is displaced according to the first characteristic by the action of the attenuator 90. In other words, the reflecting mirror 2 is displaced relatively fast.
[0083]
On the other hand, if the position error ERR is less than the determination amount d, the reflecting mirror 2 has reached the vicinity of the target angle position, so the attenuator drive control unit 92 has the attenuation characteristic of the reflecting mirror 2 as the second characteristic. Thus, the attenuator driving device 91 is controlled. Here, the second characteristic is a characteristic in which the speed operation amount of the reflecting mirror 2 is smaller than the first characteristic, and is a characteristic that draws a relatively gentle curve on the attenuation characteristic graph. The attenuator driving device 91 operates the attenuator 90 according to the control of the attenuator drive control unit 92. As a result, the reflecting mirror 2 is displaced according to the second characteristic by the action of the attenuator 90. In other words, the reflecting mirror 2 is displaced relatively slowly.
[0084]
As described above, according to the fourth embodiment, the reflecting mirror 2 is displaced at a relatively high speed until the vicinity of the target angular position is reached, and the reflecting mirror 2 is relatively moved after reaching the vicinity of the target angular position. Displace slowly. Therefore, the movement time between the two celestial bodies A and B of the reflecting mirror 2 can be shortened. Therefore, the observation efficiency can be improved.
[0085]
Other embodiments
The description of the embodiment of the present invention is as described above, but the present invention is not limited to the above-described embodiment. For example, in the above embodiment, the position compensation unit executes the position compensation process with software. However, for example, the position compensation unit may be configured by hardware including a control circuit, and the position compensation process may be executed in hardware.
[0086]
Moreover, in the said embodiment, the case where this invention is applied to the radio telescope 1 is taken as an example. However, the present invention can be easily applied to any tracking device that tracks a tracking target by receiving radio waves such as an antenna.
[0087]
【The invention's effect】
As described above, according to the present invention, the drive control of the reflecting mirror is switched depending on whether or not the vicinity of the target angle position has been reached. Travel time can be shortened. Therefore, when observing the tracking target according to the present invention, the observation efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing the configuration of a radio telescope according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing an internal configuration of the radio telescope.
FIG. 3 is a graph showing the relationship between a command signal and the actual angular position of the reflecting mirror.
FIG. 4 is a conceptual diagram showing a relationship between a reflecting mirror and two celestial bodies in an azimuth plane.
FIG. 5 is a flowchart for explaining position compensation processing;
FIG. 6 is a graph showing the magnitude of gain.
FIG. 7 is a graph for explaining a steady-state deviation.
FIG. 8 is a block diagram showing an internal configuration of a radio telescope according to Embodiment 2 of the present invention.
FIG. 9 is a flowchart for explaining position compensation processing according to the second embodiment;
FIG. 10 is a graph for explaining the effect of the second embodiment.
FIG. 11 is a conceptual diagram showing a configuration of a drive apparatus according to Embodiment 3 of the present invention.
FIG. 12 is a block diagram showing an internal configuration of a radio telescope according to Embodiment 4 of the present invention.
FIG. 13 is a graph showing a relationship between a conventional command signal and an actual angular position.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Radio telescope, 2 Reflective mirror, 10 Reflective mirror drive system, 11 Command control apparatus, 20 Reflective mirror drive control apparatus, 22, 51, 93 Position compensation part, 30 Drive apparatus, 40 Angle detection apparatus, 60 High speed drive part, 70 Low speed drive unit.

Claims (7)

  In a device that controls a driving device for driving a reflecting mirror that receives a radio wave, when receiving a displacement instruction that changes stepwise from the current angular position to the target angular position, the target until the vicinity of the target angular position is reached. Based on the difference between the angular position and the actual angle position of the reflecting mirror, the reflecting mirror is driven by an I-type control process in which overshoot does not occur, and after reaching the vicinity of the target angle position, the target angle position and the actual angle of the reflecting mirror are reached. A reflecting mirror drive control device, wherein the reflecting mirror is driven by a type II control process in which a steady deviation does not occur based on a difference from a position. In claim 1,
The I-type control process is to obtain the first speed manipulated variable without multiplying the difference between the target angular position and the actual angular position of the reflector by the first gain and integrating the multiplication result.
The type II control process is characterized in that the second speed manipulated variable is obtained by multiplying the difference between the target angular position and the actual angular position of the reflector by the second gain and integrating the multiplication result. Reflector drive control device. In claim 2,
After the end of the type I control process and before the start of the type II control process, between the first speed manipulated variable determined by the type I control process and the second speed manipulated variable determined by the type II control process. And a mirror driving control device for performing an interpolation process for driving the mirror according to the speed operation amount. In a device for controlling a driving device for driving a reflecting mirror that receives radio waves,
Receiving means for receiving a displacement instruction that changes stepwise from the current angle position to the target angle position;
Position error detecting means for detecting a position error which is a difference between the target angle position indicated by the displacement instruction received by the receiving means and the actual angle position of the reflecting mirror;
Determining means for determining whether or not the reflecting mirror has reached the vicinity of the target angular position based on the position error detected by the position error detecting means;
When it is determined by the determination means that the reflecting mirror has not reached the vicinity of the target angular position, reflection is performed with the first speed operation amount that does not cause overshoot based on the position error detected by the position error detection means. Based on the position error detected by the position error detection means when the driving device is controlled so that the mirror is displaced, and the determination means determines that the reflecting mirror has reached the vicinity of the target angular position, Control means for controlling the drive device so that the reflecting mirror is displaced by a second speed operation amount that does not produce a steady deviation larger than the first speed operation amount;
The first speed operation amount is obtained by multiplying the difference between the target angular position and the actual angular position of the reflecting mirror by the first gain and integrating the multiplication result.
2. The reflector driving control device according to claim 1, wherein the second speed operation amount is obtained by multiplying a difference between the target angular position and the actual angular position of the reflector by a second gain and integrating the multiplication result. In a drive system that drives a reflector that receives radio waves,
A high-speed drive unit that transmits the driving force generated by the motor to the reflecting mirror with a relatively low gear ratio;
A low-speed drive unit that transmits the driving force generated by the motor to the reflecting mirror at a relatively high gear ratio;
Acceptance means for accepting a displacement instruction that changes stepwise from the current angle position to the target angle position, and a position error that is the difference between the target angle position indicated by the displacement instruction accepted by the acceptance means and the actual angle position of the reflector A position error detecting means for detecting the position error, a determining means for determining whether or not the reflecting mirror has reached the vicinity of the target angle position based on the position error detected by the position error detecting means, and the determining means When it is determined that the vicinity of the target angle position has not been reached, the high-speed drive unit is operated according to the speed operation amount corresponding to the position error, and the determination means determines that the reflector has reached the vicinity of the target angle position. A control means for operating the low-speed drive unit according to the speed operation amount corresponding to the position error,
The low-speed drive unit transmits the driving force generated by the motor to the reflecting mirror by an anti-backlash driving method, and the high-speed driving unit transmits the driving force generated by the motor by the backlash driving method. Reflector driving system characterized by being transmitted to the mirror. In claim 5 , the control means includes:
When it is determined by the determination means that the reflecting mirror has not reached the vicinity of the target angular position, a first speed operation amount is calculated by multiplying the position error by a first gain, and the high speed is calculated according to the calculation result. Operate the drive,
When it is determined by the determination means that the reflecting mirror has reached the vicinity of the target angular position, an integration result obtained by multiplying the position error by a second gain and then multiplying the multiplication result and the multiplication result by an integral gain is integrated. A second mirror operation amount is calculated by adding the two and the low-speed drive unit is operated according to the calculation result. 7. The reflector driving system according to claim 5, wherein the control means variably controls the attenuation characteristic of the reflector.

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