JP7615085B2 - Guidance device - Google Patents

Description

This disclosure relates to a guidance device that guides a flying object to a moving target.

When operating an aircraft that shares information about targets via a network, it is required that the target be able to be changed according to the situation while the aircraft is in flight in order to utilize the aircraft effectively.

Patent document 1 discloses a guidance device that calculates the relative motion between a target and a flying object, and calculates an acceleration command value for the flying object until guidance is complete and the flying object meets the target, based on the result of the relative motion.

Patent No. 5577807

To increase the tolerance for target changes while the missile is flying, it is necessary to maintain the missile's altitude and speed. However, depending on the target's movement prior to the maneuver to change the target, the missile's altitude and speed may rapidly decrease due to guidance to meet the target. If the missile's altitude and speed decrease, it may become difficult to meet the target, and the tolerance for target changes may decrease. In this way, by making the missile follow the target uniformly, the tolerance for target changes while the missile is flying may decrease.

The present disclosure has been made in consideration of the above, and aims to provide a guidance device that can increase the tolerance for target changes while a flying object is flying.

In order to solve the above-mentioned problems and achieve the object, the guidance device according to the present disclosure is a guidance device that guides a flying object to a moving target. The guidance device according to the present disclosure includes a kinetic energy evaluation unit that executes a motion prediction calculation process that sets a predicted induction term that represents a bias acceleration to be added to the acceleration of the flying object and simulates the relative motion between the flying object and the target, and an evaluation and predicted induction term correction process that obtains an evaluation value that represents the amount of kinetic energy loss of the flying object in the simulated relative motion and corrects the predicted induction term in a manner that reduces the evaluation value. The kinetic energy evaluation unit repeats the correction of the predicted induction term and the simulation of the relative motion using the corrected predicted induction term until the evaluation value converges, and calculates a first guidance command that includes the predicted induction term when the evaluation value converges.

The guidance device disclosed herein has the effect of increasing the tolerance for target changes while the flying object is in flight.

FIG. 1 is a block diagram showing a configuration example of a guidance device according to a first embodiment; 1 is a flowchart showing a procedure of a process performed by a kinetic energy evaluation unit of a guidance device according to a first embodiment. FIG. 1 is a diagram for explaining a process performed by a kinetic energy evaluation unit of the guidance device according to the first embodiment. FIG. 1 is a diagram for explaining the operation of a flying object guided by a guidance device according to a first embodiment; FIG. 1 is a diagram showing a configuration example of a control circuit according to a first embodiment; FIG. 1 is a diagram showing an example of a configuration of a dedicated hardware circuit according to a first embodiment;

The following describes the guidance device according to the embodiment in detail with reference to the drawings.

Embodiment 1.
1 is a block diagram showing a configuration example of a guidance device 1 according to a first embodiment. The guidance device 1 is mounted on a flying object and guides the flying object to a moving target. The guidance device 1 is provided at a front portion of the flying object.

The guidance device 1 includes a receiver 2, an inertial device 3, and a signal processor 4. The signal processor 4 includes a target motion calculation unit 10, a kinetic energy evaluation unit 11, a duration setting unit 12, a target maneuver setting unit 13, a meeting feasibility evaluation unit 14, a guidance command generation unit 15, and a guidance command switching unit 16.

After the flying object starts flying, the receiver 2 receives target observation information from outside the guidance device 1. The receiver 2 outputs the received observation information to the signal processor 4. The inertial device 3 determines the current position and velocity of the flying object. The inertial device 3 outputs position information and velocity information of the flying object to the signal processor 4.

The target observation information is input to the target motion calculation unit 10. The target motion calculation unit 10 calculates the target's current position and velocity based on the target observation information. The target motion calculation unit 10 outputs the target's position information and velocity information to each of the kinetic energy evaluation unit 11, the duration setting unit 12, the target maneuver setting unit 13, and the guidance command generation unit 15.

The position information and speed information of the flying object are input to each of the kinetic energy evaluation unit 11 and the guidance command generation unit 15. The kinetic energy evaluation unit 11 calculates a guidance command for guiding the flying object while minimizing loss of altitude and speed, based on the position information and speed information of the target and the position information and speed information of the flying object. Hereinafter, the guidance command calculated by the kinetic energy evaluation unit 11 is referred to as the first guidance command. The kinetic energy evaluation unit 11 outputs the calculated first guidance command to each of the meeting feasibility evaluation unit 14 and the guidance command switching unit 16.

The duration setting unit 12 sets the duration based on the position information and speed information of the target. The duration is the time for which guidance with reduced loss of altitude and speed is continued. In other words, the duration is the time for which guidance based on the first guidance command is continued. The duration setting unit 12 outputs a value indicating the set duration to each of the kinetic energy evaluation unit 11 and the meeting feasibility evaluation unit 14.

The target maneuver setting unit 13 holds multiple pre-set target maneuver models. The target maneuver models are models that represent the actions that the target can take in the air. The target maneuver setting unit 13 generates a predicted route for the target during maneuver based on the target's position information and speed information and each target maneuver model. The target maneuver setting unit 13 outputs information indicating the generated predicted route to the meeting feasibility evaluation unit 14.

The meeting feasibility evaluation unit 14 evaluates the feasibility of a meeting between the aircraft and the target when guidance of the aircraft is continued by the first guidance command, based on the first guidance command, the duration, and the predicted route of the target. The meeting feasibility evaluation unit 14 simulates the movement of the aircraft and the movement of the target on the predicted route when the aircraft is guided by the first guidance command for the duration. The meeting feasibility evaluation unit 14 evaluates the feasibility of the meeting by predicting whether the aircraft will meet the target based on the results of the simulation. The meeting feasibility evaluation unit 14 outputs the evaluation result of the feasibility of the meeting to the guidance command switching unit 16.

The guidance command generating unit 15 generates a guidance command for guiding the flying object based on the target position, the target speed, the flying object position, and the flying object speed. The guidance command generating unit 15 calculates proportional navigation acceleration, which is the acceleration for guiding the flying object using proportional navigation. The guidance command generating unit 15 generates a guidance command for flying the flying object to the predicted meeting point using the calculated proportional navigation acceleration. The predicted meeting point is a point where the flying object and the target are predicted to meet. Hereinafter, the guidance command generated by the guidance command generating unit 15 is referred to as a second guidance command. The guidance command generating unit 15 outputs the second guidance command to the guidance command switching unit 16.

The guidance command switching unit 16 switches between outputting the first guidance command and outputting the second guidance command based on the evaluation result of the feasibility of the meeting by the meeting feasibility evaluation unit 14. The guidance command switching unit 16 switches between outputting the first guidance command and outputting the second guidance command by outputting the first guidance command based on the evaluation result indicating that the meeting will be established and outputting the second guidance command based on the evaluation result indicating that the meeting will not be established.

Next, the details of the processing executed by the kinetic energy evaluation unit 11 will be described. FIG. 2 is a flowchart showing the procedure of processing by the kinetic energy evaluation unit 11 of the guidance device 1 according to the first embodiment. The kinetic energy evaluation unit 11 executes a motion prediction calculation process and an evaluation and prediction guidance term correction process.

Steps S1 and S2 are procedures included in the motion prediction calculation process. In step S1, the kinetic energy evaluation unit 11 sets a predicted induction term. The predicted induction term represents a bias acceleration to be added to the proportional navigation acceleration for guiding the flying object by proportional navigation. In step S2, the kinetic energy evaluation unit 11 simulates the relative motion between the flying object and the target. The kinetic energy evaluation unit 11 receives position information and speed information of the target from the target motion calculation unit 10. The kinetic energy evaluation unit 11 receives position information and speed information of the flying object from the inertial device 3. The kinetic energy evaluation unit 11 simulates the relative motion based on the predicted induction term set in step S1, the position information and speed information of the target, and the position information and speed information of the flying object. The kinetic energy evaluation unit 11 performs evaluation and predicted induction term correction processing based on the results of the simulation.

Steps S3 and S4 are procedures included in the evaluation and predicted lead term correction process. In step S3, the kinetic energy evaluation unit 11 obtains an evaluation value that represents the amount of kinetic energy loss of the flying object in the relative motion simulated in step S2. In the first embodiment, the amount of kinetic energy loss is the amount of altitude loss and the amount of speed loss. A set value that is a value indicating the set duration is input to the kinetic energy evaluation unit 11 from the duration setting unit 12. The kinetic energy evaluation unit 11 calculates an evaluation value that is an index of the amount of altitude loss of the flying object in the set duration and the amount of speed loss of the flying object in the set duration. The set value of the duration can also be said to be a value that represents the evaluation period of the amount of kinetic energy loss of the flying object.

The kinetic energy evaluation unit 11 calculates the amount of kinetic energy loss in the evaluation period by applying the simulation results to the evaluation function. The evaluation period is a duration set by the duration setting unit 12. The evaluation function is expressed by the following formula (1). J represents the evaluation function, and N represents the evaluation period. _{K i-1} and K _i represent velocity energy K represented by the following formula (2). _{U i-1} and U _i represent kinetic energy U represented by the following formula (3). m represents the mass of the flying object, v represents the speed of the flying object, g represents the gravitational acceleration, and h represents the altitude of the flying object.

In step S4, the kinetic energy evaluation unit 11 corrects the predicted induction term in a direction that reduces the evaluation value. If the evaluation value decreases as a result of increasing the predicted induction term, the kinetic energy evaluation unit 11 corrects the predicted induction term to increase it, and if the evaluation value decreases as a result of decreasing the predicted induction term, the kinetic energy evaluation unit 11 corrects the predicted induction term to decrease it. In this way, the kinetic energy evaluation unit 11 corrects the predicted induction term in a manner that reduces the evaluation value.

In step S5, the kinetic energy evaluation unit 11 determines whether the evaluation value has converged to the minimum value of the evaluation function. If it is determined that the evaluation value has not converged to the minimum value of the evaluation function (step S5, No), the kinetic energy evaluation unit 11 returns the procedure to step S1. The kinetic energy evaluation unit 11 sets the predicted induction term corrected in step S4 in step S1, and repeats the procedures from step S2 to step S5.

On the other hand, if it is determined that the evaluation value has converged to the minimum value of the evaluation function (step S5, Yes), in step S6, the kinetic energy evaluation unit 11 calculates a first guidance command. The kinetic energy evaluation unit 11 calculates the first guidance command by adding the predicted induction term at the time when the evaluation value has converged to the proportional navigation acceleration. In this way, the kinetic energy evaluation unit 11 repeats the correction of the predicted induction term and the simulation of the relative motion using the corrected predicted induction term until the evaluation value converges, and calculates the first guidance command including the predicted induction term at the time when the evaluation value has converged. The kinetic energy evaluation unit 11 outputs the calculated first guidance command. With the above, the kinetic energy evaluation unit 11 ends the processing according to the procedure shown in FIG. 2.

Figure 3 is a diagram for explaining the processing by the kinetic energy evaluation unit 11 of the guidance device 1 according to the first embodiment. The motion prediction calculation process includes predicted lead term setting in step S1 of Figure 2 and a meeting simulation, which is a simulation in step S2. Figure 3 shows an example of the change in the predicted lead term set in the motion prediction calculation process, the change in the result of the meeting simulation, and the change in the evaluation value calculated by the evaluation and predicted lead term correction process while the motion prediction calculation process and the evaluation and predicted lead term correction process are repeated.

In FIG. 3, the predicted lead term to be set is shown by a graph showing the relationship between the predicted lead term and time. The vertical axis of the graph represents the predicted lead term. The horizontal axis of the graph represents time. FIG. 3 shows how the graph changes from the first predicted lead term setting to the nth predicted lead term setting. n is an arbitrary integer equal to or greater than 2.

In Figure 3, the simulation results of the relative motion between the flying object 20 and the target 21 in a meeting simulation are represented by the predicted route 22 of the flying object 20 and the predicted route 23 of the target 21. In the example shown in Figure 3, the predicted route 23 of the target 21 is a route that turns in the direction indicated by the arrow 24. The dashed line is a line that connects the flying object 20 moving on the predicted route 22 and the target 21 moving on the predicted route 23. Figure 3 shows how the simulation results change from the first meeting simulation to the nth meeting simulation.

In FIG. 3, the evaluation value calculated by the evaluation and predicted lead term correction process is represented by point 25 on a graph representing the evaluation function. The vertical axis of the graph represents the evaluation value. The horizontal axis of the graph represents the predicted lead term. The dashed line graph represents the evaluation function. Arrow 26 indicates the direction in which the evaluation value decreases when the evaluation value is changed from point 25 along the evaluation function graph. FIG. 3 shows the change in evaluation value and the correction of the predicted lead term in the first to nth evaluation and predicted lead term correction processes.

The kinetic energy evaluation unit 11 sets an initial value for the predicted guidance term in the first predicted guidance term setting. The initial value is set to zero, for example. The kinetic energy evaluation unit 11 executes the first meeting simulation based on the predicted guidance term, which is the initial value, the position information and speed information of the target, and the position information and speed information of the flying object. The kinetic energy evaluation unit 11 calculates a guidance command in the meeting simulation by adding the predicted guidance term to the proportional navigation acceleration.

The kinetic energy evaluation unit 11 executes the first evaluation and predicted lead term correction process based on the results of the first meeting simulation. Through the first evaluation and predicted lead term correction process, the kinetic energy evaluation unit 11 calculates an evaluation value and corrects the predicted lead term in such a manner that the evaluation value decreases. In the example shown in FIG. 3, the evaluation value calculated the first time decreases by decreasing the predicted lead term. Therefore, in the first evaluation and predicted lead term correction process, the kinetic energy evaluation unit 11 performs a correction to decrease the predicted lead term. After that, the kinetic energy evaluation unit 11 returns the process to the predicted lead term setting and performs the second predicted lead term setting.

In the second predicted lead term setting, the predicted lead term after correction by the first evaluation and predicted lead term correction process is set. As shown in FIG. 3, the graph of the predicted lead term in the second predicted lead term setting changes from that in the first predicted lead term setting. The kinetic energy evaluation unit 11 executes the second meeting simulation based on the set predicted lead term. By correcting the predicted lead term, as shown in FIG. 3, the predicted route 22 calculated by the second meeting simulation changes from the predicted route 22 calculated by the first meeting simulation. In FIG. 3, the predicted route 22 calculated by the first meeting simulation is represented by a dashed line. The kinetic energy evaluation unit 11 executes the second evaluation and predicted lead term correction process based on the result of the second meeting simulation. Thereafter, the kinetic energy evaluation unit 11 repeats the motion prediction calculation process and the evaluation and predicted lead term correction process.

In FIG. 3, it is assumed that an evaluation value that is the minimum value of the evaluation function is calculated in the nth evaluation and predicted lead term correction process. The kinetic energy evaluation unit 11 adds the predicted lead term when the evaluation value converges to the minimum value of the evaluation function, i.e., the predicted lead term set by the nth predicted lead term setting, to the proportional navigation acceleration. The kinetic energy evaluation unit 11 calculates the first guidance command by adding the predicted lead term to the proportional navigation acceleration. In this way, the kinetic energy evaluation unit 11 obtains the predicted lead term by repeating the motion prediction calculation process and the evaluation and predicted lead term correction process until the evaluation value converges to the minimum value of the evaluation function, and calculates the first guidance command including the predicted lead term.

Figure 4 is a diagram for explaining the operation of flying object 20 guided by guidance device 1 according to embodiment 1. Each of flying object 27 and flying object 28 is a flying object that can be a target 21, such as an aircraft. In Figure 4, the dashed arrow indicates the wake of flying object 20. The dashed arrow indicates the wake of flying object 27 or the wake of flying object 28. In Figure 4, the flying object 20 equipped with guidance device 1 and each of the two flying objects 27 and 28 are shown in schematic form in vertical and horizontal planes.

The upper part of Figure 4 shows a state in which flying body 27 is the target 21 and guidance device 1 is guiding flying body 20 to flying body 27. In addition, while guidance of flying body 20 to flying body 27 continues, flying body 27 performs a motion of rotating vertically downward as shown in the upper part of Figure 4. In other words, flying body 27 decreases in altitude. Note that before flying body 27 decreases in altitude, flying body 27 was flying diagonally behind flying body 28 at the same altitude as flying body 28.

If the guidance device 1 uniformly makes the flying body 20 follow the flying body 27, which is the target 21, the flying body 20 performs a maneuver to lower its altitude to match the flying body 27, as shown in the lower part of FIG. 4. At that time, the flying body 20 loses altitude and loses speed due to air resistance accompanying the maneuver. In this case, even if the target 21 to which the flying body 20 is guided is changed from the flying body 27 to the flying body 28, the flying body 20 will not be able to meet the flying body 28 because the flying body 20 has lost its altitude and speed. In this way, by making the flying body 20 uniformly follow the target 21 in order to establish a meeting before the target 21 is changed, the tolerance for target changes while the flying body 20 is flying may be low.

The guidance device 1 according to the first embodiment evaluates the kinetic energy of the flying object 20 and calculates a first guidance command for guidance with reduced loss of kinetic energy. The guidance device 1 can increase the tolerance for target change by reducing the amount of loss of kinetic energy of the flying object 20. The guidance device 1 outputs a first guidance command when an evaluation result indicating that a meeting is established is obtained, and outputs a second guidance command when an evaluation result indicating that the meeting is not established is obtained, thereby switching between output of the first guidance command and output of the second guidance command. The guidance device 1 can delay the timing at which the flying object 20 starts tracking the target 21 to the limit at which the evaluation of the meeting is changed from that of the meeting to that of the meeting not established. The guidance device 1 can obtain a guidance law that can achieve both of guiding the flying object 20 to the target 21 and increasing the tolerance for target change while the flying object 20 is flying.

Next, the hardware that realizes the signal processor 4 of the guidance device 1 according to the first embodiment will be described. The signal processor 4 is realized by a processing circuit. The processing circuit may be a circuit in which a processor executes software, or may be a dedicated circuit. When the processing circuit is realized by software, the processing circuit is, for example, the control circuit shown in FIG. 5. FIG. 5 is a diagram showing an example configuration of the control circuit 30 according to the first embodiment.

The control circuit 30 includes an input unit 31, a processor 32, a memory 33, and an output unit 34. The input unit 31 is an interface circuit that receives data input from outside the signal processor 4 and provides the data to the processor 32. The output unit 34 is an interface circuit that sends data from the processor 32 or the memory 33 to outside the signal processor 4.

When the processing circuit is the control circuit 30 shown in FIG. 5, each of the target motion calculation unit 10, kinetic energy evaluation unit 11, duration setting unit 12, target maneuver setting unit 13, meeting feasibility evaluation unit 14, guidance command generation unit 15, and guidance command switching unit 16 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in memory 33. In the processing circuit, the processor 32 reads and executes the program stored in memory 33 to realize the functions of each unit of the signal processor 4. In other words, the processing circuit includes a memory 33 for storing a program that will result in the processing of the signal processor 4 being executed. It can also be said that these programs cause a computer to execute the procedures and methods of the signal processor 4.

The processor 32 is a CPU (also called a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)). The memory 33 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc).

Figure 5 shows an example of hardware in which each component is realized by a general-purpose processor 32 and memory 33, but the signal processor 4 may be realized by a dedicated hardware circuit. Figure 6 shows an example of the configuration of the dedicated hardware circuit 35 according to the first embodiment.

The dedicated hardware circuit 35 includes an input unit 31, an output unit 34, and a processing circuit 36. The processing circuit 36 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. Each part of the signal processor 4 may be realized by the processing circuit 36 on a function-by-function basis, or each function may be realized collectively by the processing circuit 36. The signal processor 4 may be realized by combining the control circuit 30 and the hardware circuit 35.

According to the first embodiment, the guidance device 1 obtains an evaluation value representing the amount of loss of kinetic energy of the flying object 20, corrects the predicted guidance term in a manner that reduces the evaluation value, and calculates the first guidance command based on the predicted guidance term when the evaluation value converges. This provides the effect that the guidance device 1 can increase the tolerance for target change while the flying object 20 is flying. Furthermore, the guidance device 1 can achieve both of guiding the flying object 20 to the target 21 and increasing the tolerance for target change while the flying object 20 is flying by switching between the output of the first guidance command and the output of the second guidance command based on the result of evaluating the feasibility of meeting between the flying object 20 and the target 21.

The configurations shown in the above embodiments are examples of the contents of this disclosure. The configurations of the embodiments can be combined with other known technologies. Part of the configurations of the embodiments can be omitted or modified without departing from the gist of this disclosure.

1 Guidance device, 2 Receiver, 3 Inertial device, 4 Signal processor, 10 Target motion calculation unit, 11 Kinetic energy evaluation unit, 12 Duration setting unit, 13 Target maneuver setting unit, 14 Meeting feasibility evaluation unit, 15 Guidance command generation unit, 16 Guidance command switching unit, 20, 27, 28 Flying object, 21 Target, 22, 23 Predicted route, 24, 26 Arrow, 25 Point, 30 Control circuit, 31 Input unit, 32 Processor, 33 Memory, 34 Output unit, 35 Hardware circuit, 36 Processing circuit.

Claims (4)

A guidance device for guiding a flying object to a moving target,
a kinetic energy evaluation unit that executes a motion prediction calculation process that sets a predicted induction term that represents a bias acceleration to be added to the acceleration of the flying object and simulates a relative motion between the flying object and the target, and an evaluation and predicted induction term correction process that obtains an evaluation value that represents an amount of loss of kinetic energy of the flying object in the simulated relative motion and corrects the predicted induction term in a manner that the evaluation value decreases,
the kinetic energy evaluation unit repeats the correction of the predicted lead term and the simulation of the relative motion using the corrected predicted lead term until the evaluation value converges, and calculates a first guidance command including the predicted lead term when the evaluation value converges. The guidance device according to claim 1, further comprising a meeting feasibility evaluation unit that evaluates the feasibility of meeting between the flying object and the target when guidance of the flying object is continued according to the first guidance command, and outputs an evaluation result. a duration setting unit that sets a duration for continuing the guidance of the flying object by the first guidance command based on a position of the target and a speed of the target,
The guidance device according to claim 2, characterized in that the meeting feasibility evaluation unit evaluates the feasibility of a meeting when guidance of the flying object is continued by the first guidance command for the set duration. a guidance command generating unit that generates a second guidance command based on a position of the target, a velocity of the target, a position of the flying object, and a velocity of the flying object;
the guidance device according to claim 2 or 3, further comprising a guidance command switching unit that switches between output of the first guidance command and output of the second guidance command by outputting the first guidance command based on the evaluation result indicating that the meeting will be established and outputting a second guidance command based on the evaluation result indicating that the meeting will not be established.

Images