JPH0875396A - Guidance apparatus for missile - Google Patents

Abstract

PURPOSE: To perform guidance for a missile, by a method wherein a twodimensional detector is fastened the body of the missile, and while the missile is stabilized in a space by electronic data processing instead of a mechanical gimbal mechanism, guidance signals are generated. CONSTITUTION: An attitude angle velocity signal 23 of a missile is detected by an inertial sensor 6 and a tracking point angle signal 21 is detected by an image data processor 8 on the basis of an outputted image from a two-dimensional detector 3. A tracking point angle signal 22 is differential-found by a differentiator 13. On the basis of both a tracking point angle of a target and a temperature of an optical lens, a gain at the time when scale factors of these signals are made equal to each other and a phase at the time when detected times thereof are made equal to each other, are respectively adjusted by a gain adjuster 11 and a phase adjuster 12, and these values are added by an adder 14. In this way, independent of the attitude fluctuation of the missile, a change rate of a visual line angle to be formed between the missile and target is directly found and is outputted as a guidance signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying device guiding apparatus guided by an image guiding system.

[0002]

2. Description of the Related Art FIG. 8 is a diagram showing a structure of a flying body guided by a conventional image guiding system. Reference numeral 1 denotes a radome or an optical dome (hereinafter referred to as a dome) that has low aerodynamic resistance and transmits a signal medium for target detection such as light and radio waves.
Reference numeral 2 is an optical lens for condensing a signal medium transmitted through the dome 1 on a detector, and 3 is capable of forming an image in a range of a predetermined direction.
Dimensional detector, 4 is a dewar for cooling the two-dimensional detector 3, 5 is a flying shell, 6 is an inertial sensor, and 48 is a mechanical device for stabilizing the visual field of the two-dimensional detector 3 in the inertial space. 2 shows a biaxial gimbal mechanism.

FIG. 9 is a block diagram showing the function and configuration of a conventional guiding device. Reference numeral 7 is an A / D converter for converting the output image signal of the two-dimensional detector 3 into a digital signal, 9 is a target extraction processing circuit for extracting a target from the output image signal, 10
Is a target tracking processing circuit for tracking the target selected by the target extraction processing circuit 9, and 49 is a command for stabilizing the two-dimensional detector 3 in the inertial space from the attitude angle signal and the tracking error signal and directing it toward the target. The space stabilization processing circuit for giving the torka of the gimbal mechanism 48 is shown.

FIG. 10 is a diagram showing the definition of an angle in an image obtained by a conventional guiding device. 25 is a flying object, 26
Is the field of view of the two-dimensional detector, 27 is the inertia reference coordinate axis, 28 is the machine axis, 29 is the target, 30 is the attitude angle, 52 is the gimbal center, 53 is the gimbal angle, 54 is the tracking error angle, and 55 is the gimbal with respect to the inertia reference coordinate axis. Indicates the angle.

FIG. 11 is a control block diagram of a conventional guidance device. 3t is the storage time of the two-dimensional detector, 6d is the attitude angle detection of the inertial sensor 6, and 8t is the target extraction processing circuit 9
And the signal processing time of the image processor constituted by the target tracking processing circuit 10, 30 is the posture angle, 32 is the line-of-sight angle, 3
3 is integration, 34 is an inductive signal filter, 48d is gimbal angle detection, and 56 is homing head gain.

The conventional guiding device is constructed as described above,
In FIG. 8, when the attitude angle of the flying object 25 changes due to the motion of the airframe and the motion of the flying object 25, the inertial sensor 6 detects the amount of change and the two-dimensional detector 3 has a spatially constant visual field. The gimbal mechanism 48 is driven by an amount corresponding to the change in the posture angle so as to face the direction. In FIG. 9, 2
The image signal detected by the dimension detector 3 is subjected to target tracking processing by the target extraction processing circuit 9 and the target tracking processing circuit 10 to generate a guidance signal 24 proportional to the tracking error and also to output the tracking error angle signal 22. Feedback is given to the space stabilization processing circuit 49, and a swing command 51 is sent to the Toruca of the gimbal mechanism 48 so that the two-dimensional detector 3 always tracks the target.

In FIGS. 10 and 11, in the case of space stabilization, the inertia reference coordinate axis 2 with respect to changes in the posture angle 30.
In order to orient the gimbal angle 55 with respect to 7 in a fixed direction, the gimbal swing angle command 51
Are in control. Further, in the case of tracking, the gimbal direction with respect to the inertial reference coordinate axis 27 is kept constant and the above-mentioned spatial stabilization is maintained, while the target tracking processing circuit 10 within the visual field 26.
The gimbal swing angle command 51 is given by the space stabilization processing circuit 49 so as to control the gimbal angle 55 with respect to the inertia reference coordinate axis 27 by the tracking error angle signal 22 corresponding to the homing head gain 56.

[0008]

The conventional guiding device for the flying body guided by the image guiding system is configured as described above, and the space is provided through a complicated mechanical movable portion such as the gimbal mechanism 48. Since the stabilization is achieved, the deterioration of the space stabilization performance due to the friction of the bearing is unavoidable. In addition, it has been a heavy burden to reduce the size, cost and reliability of the induction device.

The present invention has been made in order to solve the above-mentioned problems. Since the sensor is fixed to the flying body, the visual linear angular velocity necessary for guiding the flying body can be detected. The purpose of the present invention is not to have a mechanically movable part such as the gimbal mechanism 48, to achieve miniaturization and cost reduction of an induction device and to obtain high reliability.

[0010]

A guiding device according to the present invention is a two-dimensional detector fixed to a body and capable of forming an image in a range of a predetermined direction, and a target tracking point from an output image signal of the detector. An image processor that detects the angle, a differential calculator, an inertial sensor that detects the attitude angular velocity of the flying object, a target tracking point angle differential signal, and the attitude angular velocity signal of the flying object detected by the inertial sensor It is provided with an adder, a gain adjuster, and a phase adjuster.

Further, as a phase adjuster, the detection signal of the attitude angle of the flying object by the inertial sensor is used, and half of the charge accumulation time of the two-dimensional detector and the tracking point angle output by the image processor after charge accumulation are output. A delay circuit is added to give a delay corresponding to a time obtained by subtracting the processing time of the inertial sensor from the time until the signal is differentiated by the differentiating unit and the tracking point angle differential signal is output.

Further, a circuit for controlling the delay time of the delay circuit according to the target tracking point angle is added.

Further, the distortion data of the optical lens is stored in advance as a correction value in a memory in the gain adjuster.

Further, a temperature monitor device for measuring the temperature of the optical lens is further provided, and a memory in the gain adjuster is provided with:
The correction value of the angle conversion for the variation of the focal length of the optical lens due to the temperature change is stored in advance.

[0015]

The guiding device according to the present invention calculates the target tracking point angle from the image signal detected by the two-dimensional detector for each frame rate, and differentiates the calculated tracking point angle with the attitude angular velocity signal of the flying object. An adder adds a signal to which a predetermined gain and a time delay have been given by the adjuster and the gain adjuster, and outputs as an induction signal.

Further, since there is a phase difference between the attitude angular velocity signal of the flying object detected by the inertial sensor and the tracking point angle differential signal obtained from the image signal detected by the two-dimensional detector, it is the same as the image detection. In order to be able to add the posture angular velocity at time, the inertial sensor processing is performed from the total of the processing time until the posture angular velocity signal is ½ of the charge accumulation time of the two-dimensional detector and the tracking point angle differential signal after charge accumulation is output. Delay by the amount of time subtracted.

Further, in the case where the charge storage method of the two-dimensional detector is of a type in which the charge is accumulated with a time difference depending on the pixel, the time difference varies depending on the position (angle from the machine axis) of the processing area, and therefore the field of view. The delay time is controlled according to the angle from the center to the target tracking point.

Further, since distortion occurs in the optical lens and the actual angle and the angle on the image detected by the two-dimensional detector do not have a linear relationship in the entire field of view, When the target angle is detected on the image, the correction value for correcting how many times it corresponds to the actual angle is stored in memory, and the correction value is read from the memory according to the target tracking point angle. , Correction is applied when the tracking point angle is output.

Further, since the refractive index of the optical lens changes depending on the ambient temperature, which equivalently changes the focal length, the change of the focal length with respect to temperature and the scale factor to be converted with respect to the focal length are investigated beforehand. Then, by storing this in a memory, the temperature of the optical lens is monitored and an appropriate gain is set according to the temperature.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a part of the configuration of the guiding device according to the present invention. The two-dimensional detector 3 does not have a gimbal structure like the conventional guiding device shown in FIG. It has been fixed to.

FIG. 2 is a block diagram showing an example of the function and configuration of the guiding device of the present invention. Reference numeral 7 is an A / D converter for converting the output image signal of the two-dimensional detector 3 into a digital signal,
8 is an image processor for processing the digital image signal obtained by the A / D converter 7, 9 is an image processor 8 and is a target extraction processing circuit for extracting a target from the image signal, and 10 is an image processor 8. The target tracking processing circuit configured to track the extracted target and output the tracking point angle, 11 is a gain adjuster that adjusts the gain with respect to the tracking point angle signal output from the target tracking processing circuit 10, and 12 is the inertial sensor 6 The phase adjuster for adjusting the phase of the attitude angle signal of the flying object detected in step 13, 13 is a differential calculator for differentiating the tracking point angle signal, and 14 is the tracking point angle differential signal and attitude angular velocity signal output from the differential calculator 13. Is added to the phase adjuster 12, a delay circuit for giving a delay time to the posture angular velocity signal, and 16 is included in the phase adjuster 12, and the tracking point angle signal output from the target tracking processing circuit 10 is added. According to A delay time control circuit for controlling the delay time of the delay circuit 15, 17 is provided in the gain adjuster 11, a gain for adjusting the scale factor of the tracking point angle output from the target tracking processing circuit 10, and 18 is provided in the gain adjuster 11. A distortion correction memory configured to store a gain correction value based on the distortion characteristic of the optical lens 2, and a gain adjuster 11 configured to store a correction value for correcting a focal length variation due to the temperature of the optical lens 2. A correction memory, 20 is an optical lens temperature monitor for measuring the temperature of the optical lens 2, 21 is a tracking point angle signal detected by the image processor 8, 22 is a tracking point angle differential signal obtained by differentiating the tracking point angle signal 21, and 23 is The attitude angular velocity detected by the inertial sensor 6 and 24 are induction signals.

FIG. 3 is a diagram showing the definition of angles in an image obtained by the two-dimensional detector 3, where 25 is a flying object,
26 is a visual field of the two-dimensional detector 3, 27 is an inertia reference coordinate axis,
28 is the center of the visual field (machine axis), 29 is the target, 30 is the detected posture angle, 31 is the angle of the target within the visual field, and 32 is the line-of-sight angle. Further, FIG. 4 is a control block diagram corresponding to the configuration of FIG. 2 as a representative, 33 is an integral, and 34 is an induction signal filter. Further, FIG. 5 is a diagram showing the timing of charge accumulation and charge transfer of a detector of the type in which charge is sequentially accumulated for each line as an example of the two-dimensional detector 3, and 35 is each of the two-dimensional detector 3. The charge storage time for each horizontal line, and 36 indicates the charge transfer time for each horizontal line of the two-dimensional detector 3.

FIG. 6 is a diagram showing the relationship between the focal length of the optical lens 2, the incident angle and the image height. 37 is an optical lens 2
Is the incident angle θ of the target 29 when the focal length is f, 39 is the image height y of the two-dimensional detector 3 of the target 29 when the focal length is f, and 40 is the focal length f which fluctuates with temperature. ', 41 is the position of the optical lens 2 in the case of the focal length f', 42 is the incident angle θ'of the target 29 in the case of the focal length f ', 43 is the two-dimensional detector of the target 29 in the case of the focal length f' The image height y'on 3 is shown. 7 is a graph showing the relationship between the incident angle 38 and the image height 39, 44 is a graph of y = θ, 45 is a graph of y = fSinθ, 46 is a graph showing distortion characteristics of the optical system, and 47 is y. A graph of '= f'Sin θ'is shown.

In the guiding device configured as described above, the output image signal of the two-dimensional detector 3 is the A / D converter 7
Is converted into a digital signal by the target extraction processing circuit 9 and the target tracking processing circuit 10 of the image processor 8 to detect the target tracking point angle signal 21. A gain adjuster 11 applies a predetermined gain to the tracking point angle signal 21 so as to match the posture angular velocity signal with the amplitude level, and differentiates it with the differential calculator 13 to obtain a tracking point angle differential signal 22. On the other hand, the posture angular velocity signal 23 detected by the inertial sensor 6 is the phase adjuster 12
The delay circuit 15 is given a predetermined delay time to match the time when the image is acquired, and then is sent to the adder 14,
Tracking point angle differential signal 22 and attitude angular velocity signal 2 at the same time
3 is added together to obtain the induction signal 24. Then, this guidance signal is output to an actuator provided in the body of the flying body 25, and is used as a signal for controlling each part of the body such as closing the wings of the body.

In FIG. 3, the guidance signal of the flying object 25 is to obtain the rate of change of the line-of-sight angle 32 which is the angle of the target 29 with respect to the inertial reference coordinate axis 27. According to the method of the present invention, the axis 28 of the flying object 25 and the center of the visual field 26 of the two-dimensional detector 3 are made to coincide with each other. When the angle of the target 29 from the center of the field of view that coincides with the machine axis 28 in the field of view 26 detected by the two-dimensional detector 3 is set as the tracking point angle 31, the sum of the posture angle 30 and the tracking point angle 31 is the line-of-sight angle 32. Therefore, by adding the posture angular velocity signal 23, which is the differential value of the posture angle 30, and the tracking point angle differential signal 22 obtained by differentiating the tracking point angle 31, the required rate of change of the line-of-sight angle 32 is obtained. An inductive signal 24 can be obtained.

In the guidance of the flying body 25, space stabilization means to accurately detect the visual linear angular velocity so that the two-dimensional detector 3 is placed in the inertial space regardless of the change in the attitude angle 30 of the flying body 25. , Which is fixed on the signal. In the method of the present invention, this is performed on the signal. Therefore, the tracking point angle differential signal 22 and the posture angular velocity signal 23 to be added must be signals at the same time. In FIG. 4, since the tracking point angle differential signal 22 is detected, it takes a time corresponding to the accumulation time of the two-dimensional detector 3, the signal processing time by the image processor 8 and the time constant of the differential calculator 13, so that the inertial sensor The delay time is given to the posture angular velocity signal 23 detected in 6 by the delay circuit 15 and the phases of the signals to be added are adjusted to achieve the spatial stabilization.

Next, as shown in FIG. 5, when a two-dimensional detector of the type in which the timing of charge accumulation and data transfer in the two-dimensional detector 3 is different for each line is used, the upper end of the detector is used. The charge accumulation time 35a of the pixel of No. 2 and the charge accumulation time 35b of the pixel at the lower end have different charge accumulation times, and if there is only one delay time given by the delay circuit 15, a phase adjustment error occurs. Therefore,
The tracking point angle signal 21 detected by the image processor 8 is transferred to the phase adjuster 12, and the delay time given by the delay circuit 15 by the delay time control circuit 16 is made proportional to the size of the tracking point angle 21, for example. Control.

Next, as a characteristic of the optical lens, the visual field 26
Becomes larger, distortion occurs in the peripheral portion, so that the relationship between the image height y39 and the incident angle θ38 is the original y = S as shown in FIG.
In some cases, the relation 45 of inθ may not be established, and the distortion characteristic 46 may be exhibited. In this case, when the detected image height y39 is converted into an angle, the amplitude scale factor varies depending on the size of the image height y39 (equivalent to the tracking point angle 21). θ = Ay ³ + By ² + Cy +
d) and the coefficient of the approximate expression or the approximated result at each point is used as distortion correction data.
Keep it in memory. As a result, the distortion characteristics are corrected for the tracking point angle (pixel or image height in this dictionary, not the angle in this dictionary) detected by the image processor 8 to obtain the true incident angle θ38.
(Tracking point angle 21) can be detected. Although the approximation formula varies depending on the sensor and the optical lens, approximation precision sufficient for correction can be obtained by approximation of a cubic formula.

Next, referring to FIG. 6, the original optical lens 2
When the temperature changes at the position of, the refractive index of the lens changes, so that the equivalent focal length changes from f37 to f'40.
Changes to As a result, the image height of the target 29 on the two-dimensional detector 3 also changes from y39 to y'43, and an error occurs in the tracking point angle 22 detected by the image processor 8 (two-dimensional detection). The incident angle on the instrument 3 is also from θ38 to θ '
However, since the distance to the target 29 is sufficiently larger than the focal length, it is considered that θ and θ ′ are substantially equal to each other. In FIG. 7, the relationship between the image height y39 and the incident angle 38 before the temperature change occurs is as shown by a graph 45 of y = fSinθ, and when the temperature change occurs, y = f ′.
A graph 47 of Sin θ ′ is obtained. Therefore, the optical lens temperature monitor 20 is added to the optical lens 2, and data for correction conversion of y = fSinθ45 and y = f′Sinθ′47 with respect to the temperature of the optical lens 2 is stored in the temperature correction memory 19 in advance. Then, a correction value is read from the temperature correction memory 19 of the gain adjuster 11 according to the detected temperature of the optical lens 2 and the gain 17 is corrected,
It is possible to accurately detect the tracking point angle 23 and prevent deterioration of the space stabilization performance even with respect to temperature fluctuations.

[0030]

The present invention is configured as described above, and moves the flying object to the target at high speed,
The higher the relative speed between the flying object and the target, such as the target approaching the flying object at a high speed, the more effective it is, and the following effects are achieved.

Since a two-dimensional detector can be fixed to the body and electronic processing can be performed to achieve spatial stabilization and generation of inductive signals without having a complicated mechanical moving part such as a gimbal mechanism, In addition to being able to reduce the size and cost of the induction device, the reliability is improved.

Also, the spatial stabilization characteristic is improved by matching the phase of the target image signal detected by the two-dimensional detector with the phase of the body attitude angle signal detected by the inertial sensor.

Further, by controlling the delay time in accordance with the tracking point angle in the delay circuit for adjusting the time,
Even if the target is detected at any position in the wide field of view of the two-dimensional detector,
Stable spatial stabilization characteristics can be obtained.

Further, with respect to the optical distortion generated around the visual field of the optical lens, the distortion characteristic is stored in advance in the distortion correction memory, and the tracking point angle is detected by correcting the distortion with respect to the detected image height. As a result, the signal amplitude is accurately adjusted, and stable spatial stabilization characteristics can be obtained even if an optical lens with a wide field of view is used.

Further, an optical lens temperature monitor is added to the variation of the equivalent focal length of the optical lens due to the temperature change, and the gain of the temperature correction memory is corrected according to the temperature of the optical lens to obtain the signal. Stable spatial stabilization characteristics can be obtained by adjusting the amplitude.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of a guiding device of the present invention.

FIG. 2 is a block diagram showing the function and configuration of the guiding device of the present invention.

FIG. 3 is a diagram showing a definition of an angle in an image obtained by a two-dimensional detector which is a constituent element of the guiding device of the present invention.

FIG. 4 is a control block diagram of the guiding device of the present invention.

FIG. 5 is a diagram showing the timing of charge imposition and charge transfer for one embodiment of the two-dimensional detector that is a component of the present invention.

FIG. 6 is a diagram showing the relationship between the focal length, the incident angle, and the image height of the optical lens that is a component of the present invention.

FIG. 7 is a diagram showing a relationship between an incident angle and an image height of an optical system which is a constituent element of the present invention.

FIG. 8 is a cross-sectional view showing a part of a conventional guiding device.

FIG. 9 is a block diagram showing the function and configuration of a conventional guiding device.

FIG. 10 is a diagram showing the definition of angles in an image obtained by a conventional guiding device.

FIG. 11 is a control block diagram of a conventional guidance device.

[Explanation of symbols]

1 ... radome or optical dome, 2 ... optical lens, 3 ... 2
Dimensional detector, 4 ... Dewar, 5 ... Shell, 6 ... Inertial sensor, 7 ... A / D converter, 8 ... Image processor, 9 ... Target extraction processing circuit, 10 ... Target tracking processing circuit, 11 ... Gain adjuster , 12 ... Phase adjuster, 13 ... Differentiator, 14 ... Adder, 15 ... Delay time control circuit, 16 ... Delay circuit, 17 ...
Gain, 18 ... Distortion correction memory, 19 ... Temperature correction memory, 20 ... Optical lens temperature monitor, 21 ... Tracking point angle signal, 22 ... Tracking point angle differential signal, 23 ... Posture angular velocity signal, 24 ... Guidance signal, 25 ... Fly Body, 26 ... Field of view of two-dimensional detector, 27 ... Inertia reference coordinate axis, 28 ... Field of view (machine axis), 29 ... Target, 30 ... Attitude angle, 31 ... Tracking point angle, 32 ... Visual line angle, 33 ... Integral, 34 ... Induction signal filter, 35 ... Charge accumulation time for each horizontal line of two-dimensional detector, 36 ... Charge transfer time for each horizontal line of two-dimensional detector, 37 ... Focal length f, 38 of optical lens
The target incident angle θ in the case of the focal length f, 39 ... The image height y on the two-dimensional detector in the case of the focal length f, 40 ... The focal length f ′, 41 ... Position of the optical lens, 42 ... Target incident angle θ'in case of focal length f ', 43 ... Image height y'on the two-dimensional detector in case of focal length f', 44 ... Graph of y = fθ , 45 ... y =
Graph of fSinθ, 46 ... Image height y of optical system and incident angle θ
Distortion characteristics, 47 ... y '= f' fluctuated due to temperature change
Sin θ ′ graph, 48 ... Gimbal mechanism, 49 ... Spatial stabilization processing circuit, 50 ... Attitude angle signal, 51 ... Gimbal swing angle command, 52 ... Gimbal center, 53 ... Gimbal angle, 54 ... Tracking error angle, 55 ... gimbal angle with respect to inertia reference coordinate axis, 56 ... homing head gain.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G05D 1/12 G G06T 1/00 H04N 7/18 G

Claims (5)

[Claims] 1. An optical lens fixed to a body for condensing incident light in a range of a predetermined direction, a two-dimensional detector capable of forming an image condensed by the optical lens, and an output image of the detector. An image processor that inputs a signal, extracts and tracks the target, detects the angle of the target from the center of the field of view as the tracking point angle, and a differential operation that differentiates the target tracking point angle signal detected by this image processor. And an inertial sensor that detects the attitude angular velocity of the flying object, an adder that adds the target tracking point angle differential signal and the flying object attitude angular velocity signal detected by the inertial sensor, and the tracking point angle differential signal A guide device for a flying vehicle, comprising: a gain adjuster for adjusting an amplitude difference between a signal and an attitude angular velocity signal; and a phase adjuster for adjusting a time delay between the tracking point angle differential signal and the attitude angular velocity signal. . 2. A phase adjuster, which has a delay circuit for giving a delay time to an output signal, and has a charge accumulating time of a two-dimensional detector and a differential calculator of a tracking point angle signal output from an image processor after the charge accumulation. 2. The attitude angular velocity signal is delayed by a time obtained by subtracting the processing time of the inertial sensor from the time required for the differential to output the tracking point angle differential signal.
The flying device guidance device described. 3. The phase adjuster has a circuit for controlling the delay time of the delay circuit for each frame of the image signal detected by the two-dimensional detector, and according to the angle from the center of the visual field to the target tracking point, 3. The flying body guiding apparatus according to claim 2, wherein the delay time is controlled. 4. As a gain adjuster, distortion data of an optical lens is stored in advance as a correction value, and gain correction is applied to a tracking point angle signal according to an angle from a visual field center to a target tracking point. The flying device guiding apparatus according to claim 1. 5. An optical lens temperature monitor device for measuring the temperature of an optical lens is provided, and gain variation is corrected by a gain adjuster with respect to variation in equivalent focal length of the optical lens due to temperature variation. The flying device guiding apparatus according to claim 1.