Rapid planning method for minimum safety control area of ​​supersonic cruise target missile

Abstract

The present invention discloses a method for rapid planning of a minimum safety control area for a supersonic cruise target missile, comprising: randomly extracting a number of parameter values ​​as the initial population of a genetic algorithm in the design space of the design variables of trajectory planning; generating the initial trajectory corresponding to each individual in the current population based on a hybrid A* algorithm; calculating the energy consumption evaluation index of the initial trajectory, and using the energy consumption evaluation index as the fitness function of the genetic algorithm to generate a new generation of populations; judging whether the stopping criterion is met, and if so, using the initial trajectory with the minimum corresponding energy consumption evaluation index in the current population as the final trajectory planning result. The present invention is applied to the field of path planning, discretizing the safety control area, retaining the shape characteristics of the safety control area, and finding the optimal path planning through a genetic algorithm, which can effectively improve the trajectory planning capability of a supersonic cruise target missile in a complex safety control area.

Description

Technical Field

[0001] The invention relates to the technical field of path planning, in particular to a method for quickly planning a minimum safety control area for a supersonic cruise target missile. Background Art

[0002] Trajectory planning for hypersonic vehicles has always been a key and hot topic in research. Its trajectory needs to meet constraints such as dynamic pressure, heat flux density, terminal state and maneuverability. However, with the continuous development of the economy and society, especially the rapid construction of offshore oil fields and cities, in order to ensure the safety of life and property, hypersonic vehicles also need to meet increasingly complex path constraints. The number of security control areas is large and the distribution is complex, making trajectory planning difficult.

[0003] For a long time, the trajectory planning of hypersonic vehicles under security control zone constraints has attracted extensive attention from scholars at home and abroad. Zhang Yuan et al. proposed a double-layer planning of path-trajectory of hypersonic vehicles under complex no-fly zone constraints to avoid the trajectory from falling into local solutions and reduce the simplification error of the motion model; Zhang Dong et al. studied the lateral trajectory planning method of cruise missiles under complex path constraints, and designed a trajectory deviation corridor based on the no-fly zone avoidance strategy of aerospace vehicles to avoid no-fly zones; Hui Junpeng et al. proposed a research framework of intelligent guidance for flying around no-fly zones based on reinforcement learning; Zhao Liangbo et al. proposed a no-fly zone avoidance guidance method based on approximate analytical solutions for the no-fly zone avoidance problem of reentry vehicles; Quan Shenming et al. proposed a three-dimensional guidance method based on the improved artificial potential field method for the reentry guidance problem of hypersonic vehicles with no-fly zone constraints.

[0004] However, in order to simplify the difficulty of trajectory planning under complex environments and constraints, the above-mentioned existing technologies have greatly simplified the security control area, simplifying the irregular security control area into a circle. In fact, with economic construction and social development, traditional flight test sites have been gradually compressed, new buildings and settlements have continued to emerge, and some aircraft have different usage requirements under specific usage backgrounds, and need to avoid cities, economic activity areas and other areas. Using a circle to approximate the actual security control area is not enough to characterize the characteristics of the security control area, and the approximation is relatively strict, which will result in the inability to find a feasible solution in some cases. Therefore, it is necessary to find a trajectory planning method that does not over-simplify the shape of the actual security control area and can generate a trajectory that meets the aircraft dynamics and path constraints. Summary of the invention

[0005] In view of the deficiencies in the above-mentioned prior art, the present invention provides a method for rapid planning of the minimum safety control area of ​​a supersonic cruise target missile, introduces a hybrid A* algorithm into the trajectory planning of the supersonic cruise target missile, discretizes the safety control area, retains the shape characteristics of the safety control area, and finds the optimal path planning through a genetic algorithm, simplifies the trajectory planning of the aircraft in a complex safety control area into geometric path planning in a complex safety control area and trajectory planning combined with a kinematic model, thereby improving the trajectory planning capability of the supersonic cruise target missile in a complex safety control area.

[0006] To achieve the above object, the present invention provides a method for rapid planning of a minimum safety control area for a supersonic cruise target missile, comprising the following steps:

[0007] Step 1, establish the aircraft motion dynamics model and path constraints, and perform grid processing on the map to obtain a grid map, in which the initial value of the grid is 0, and the grids passed by and surrounded by the closed curve formed by the outer contour of the security control area are assigned a value of 1;

[0008] Step 2, randomly selecting a number of parameter values ​​in the design space of the design variables of the trajectory planning as the initial population of the genetic algorithm, wherein the design variables include the control quantity sampling value and the steering angle, the safety distance of the safety control area and the angle penalty coefficient;

[0009] Step 3, based on the grid map, the aircraft motion dynamics model and the path constraint, generating an initial trajectory corresponding to each individual in the current population based on a hybrid A* algorithm;

[0010] Step 4, calculating the energy consumption evaluation index of the initial trajectory, and using the energy consumption evaluation index as the fitness function of the genetic algorithm to generate a new generation of population;

[0011] Step 5: Determine whether the stopping criteria are met:

[0012] If so, the initial trajectory corresponding to the minimum energy consumption evaluation index in the current population is taken as the final trajectory planning result and output;

[0013] Otherwise, return to step 3.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] The present invention uses a hybrid A* algorithm to discretize the security control area, which can better represent the shape characteristics of the security control area compared to the circular security control area. At the same time, the energy consumption of the trajectory is used as an evaluation indicator, and the optimal path planning is found through a genetic algorithm. The trajectory planning of the aircraft in a complex security control area is simplified into the geometric path planning of the complex security control area and the trajectory planning combined with the kinematic model, thereby improving the trajectory planning capability of the supersonic cruise target missile in a complex security control area. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of a method for rapid planning of a minimum safety control area for a supersonic cruise target missile in an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of grid map construction in an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of a security control area in an example of an embodiment of the present invention.

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] This embodiment discloses a method for rapid planning of the minimum safety control area of ​​a supersonic cruise target missile, which is mainly used for rapid path planning with minimum energy consumption for hypersonic aircraft such as supersonic cruise target missiles in scenarios with complex safety control areas. By introducing the hybrid A* algorithm into the trajectory planning of supersonic cruise target missiles, the safety control area is discretized, the shape characteristics of the safety control area are retained, and the optimal path planning is found through a genetic algorithm, and the trajectory planning of the aircraft in a complex safety control area is simplified to the geometric path planning of the complex safety control area and the trajectory planning combined with the kinematic model, thereby improving the trajectory planning capability of supersonic cruise target missiles in complex safety control areas.

[0024] In this embodiment, the following assumptions are made to facilitate trajectory planning:

[0025] Since the altitude of a supersonic cruise target missile changes little during its cruising flight, only its movement within the plane is considered and two-dimensional trajectory planning is performed;

[0026] Trajectory planning is more concerned with the movement of the center of mass of the aircraft. To simplify the calculation, the following assumptions are made when establishing the dynamic model: the aircraft is face-symmetrical and uses banked turning control; the ideal control assumption is adopted, and the control command is equal to the actual output; the instantaneous balance assumption is adopted to eliminate the influence of inertia; the angle of attack of the aircraft is a constant during flight.

[0027] refer to Figure 1 The method for rapid planning of the minimum safety control area of ​​a supersonic cruise target missile in this embodiment specifically includes the following steps:

[0028] Step 1: Establish the aircraft motion dynamics model and path constraints, and perform grid processing on the map to obtain a grid map. In the grid map, the initial value of the grid is 0, and the grids passed by and surrounded by the closed curve formed by the outer contour of the security control area are assigned a value of 1, that is, the map area containing irregular security control areas is converted into grid data represented by 0 / 1 values, that is, Figure 2 As shown;

[0029] Step 2, randomly extracting a number of parameter values ​​in the design space of the design variables of the trajectory planning as the initial population of the genetic algorithm, wherein the design variables include the control quantity sampling value and the steering angle, wherein the control quantity sampling value is the length of the trajectory generated by each step of the hybrid A* algorithm trajectory planning process, and the steering angle is the maximum deflection direction of the trajectory calculated by each step of the hybrid A* algorithm trajectory planning process;

[0030] Step 3: Based on the grid map, the aircraft motion dynamics model and the path constraints, the initial trajectory corresponding to each individual in the current population is generated based on the hybrid A* algorithm;

[0031] Step 4, calculate the energy consumption evaluation index of the initial trajectory, and use the energy consumption evaluation index as the fitness function of the genetic algorithm to generate a new generation of population;

[0032] Step 5: Determine whether the stopping criteria are met:

[0033] If so, the initial trajectory with the smallest corresponding energy consumption evaluation index in the current population is taken as the final trajectory planning result and output;

[0034] Otherwise, return to step 3.

[0035] In the specific implementation process of step 1, the aircraft motion dynamics model is specifically:

[0036] ;

[0037] ;

[0038] ;

[0039] ;

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] In the formula, is the distance from the center of the earth to the aircraft; and are the longitude and latitude of the aircraft respectively; is the speed of the aircraft relative to the earth; is the track inclination; is the track deflection angle, The angle between the projection on the local horizontal plane and the true north direction is positive if it rotates clockwise; is the tilt angle; is the angular velocity of the Earth's rotation; is the acceleration due to gravity; is the mass of the aircraft; is the lift of the aircraft, is the lift coefficient; is the aircraft drag, is the drag coefficient; It is the dynamic pressure of the aircraft; is the aircraft reference area.

[0045] In the specific implementation process of step 1, the path constraints of the aircraft include control constraints, thermal flow constraints, dynamic pressure constraints, overload constraints and no-fly zone constraints.

[0046] The flight control quantity of the aircraft is usually the roll angle and angle of attack , the angle of attack of the aircraft in this embodiment is a constant, so only the roll angle needs to be considered. Considering the limited control capability of the aircraft, the roll angle and the rate of change of the roll angle are restricted, that is, the control constraint is:

[0047] ;

[0048] ;

[0049] In the formula, is the maximum tilt angle, which is 45° in this embodiment; is the maximum roll angle change rate, which is taken as 20° / s in this paper.

[0050] To prevent the aircraft from overheating during flight, the aircraft must also meet the heat flow constraints, which are:

[0051] ;

[0052] In the formula, is the stagnation point heat flux density at the head of the aircraft, is the atmospheric density; is the heat flux coefficient related to the aircraft. ; In order to obtain the maximum heat flux density that the aircraft can withstand, this embodiment takes .

[0053] The aircraft also needs to limit the dynamic pressure, that is, the dynamic pressure constraint is:

[0054] ;

[0055] In the formula, is the maximum dynamic pressure that the aircraft can withstand. .

[0056] The aircraft must also meet the overload constraints during flight, which are:

[0057] ;

[0058] In the formula, is the maximum overload that the aircraft can bear. .

[0059] It is worth noting that in the specific implementation process, the design variables in step 2 are not limited to only including the control quantity sampling value and the steering angle, but also can include the safety distance of the security control area and the angle penalty coefficient. In step 3, the hybrid A* algorithm is a path planning method based on the A* algorithm, which is used to find the shortest path from the starting point to the end point in a given grid map. The grid map in this embodiment contains information about the surrounding environment, that is, the area assigned a value of 0 is a feasible area, and the area assigned a value of 1 is a security control area. The basic principle of the hybrid A* algorithm is: in the search process, according to the heuristic estimated distance between the current node and the target node, the node and neighbor expansion order is dynamically adjusted, so as to give priority to the path closer to the target node, thereby speeding up the search speed, and introducing local smoothness between the nodes to make the path smoother and more natural. As for the use of the hybrid A* algorithm to perform trajectory planning in the grid map under the premise of known control quantity sampling value, steering angle, safety distance of the security control area, angle penalty coefficient, aircraft motion dynamics model and path constraints, it is a relatively well-known technical means, so this embodiment will not be repeated.

[0060] When an aircraft passes through a security control area, it is often necessary to perform a large lateral maneuver. In order to better evaluate the energy consumption of the aircraft's lateral maneuver under different initial trajectories, this embodiment uses the energy consumption of the initial trajectory as an evaluation index. The definition of the energy consumption evaluation index is:

[0061] ;

[0062] In the formula, is the lateral acceleration of the aircraft during movement; is the minimum control force distributed laterally, i.e. It is an important indicator of energy consumption when the aircraft is gliding without power. It is the energy consumption evaluation index.

[0063] In the specific implementation process, for an initial trajectory, the calculation process of its energy consumption evaluation index is:

[0064] Step 4.1, wait for the flight distance to be taken on the initial path path points, and assign them according to the arrival time of the aircraft Sorting, that is , and then according to the geometric relationship between the aircraft and the path points, the aircraft motion dynamics model is improved as follows:

[0065] ;

[0066] In the formula, The current moment of the aircraft and The relative great circle distance of the path points, The current moment of the aircraft and The sight angle of the path points, is the heading error;

[0067] Step 4.2, at the current moment Next, obtain the remaining flight time for the aircraft to reach each path point, and obtain the position error between the aircraft's current position and each path point. Specifically:

[0068] definition is the current target path point sequence number of the aircraft, and the path point with the smallest sequence number that has not been passed is the current target path point, that is:

[0069] ;

[0070] in, For aircraft The longitude of the moment, For the The longitude of the waypoints, For the The longitude of the waypoint;

[0071] When the aircraft approaches the target path point, the arrival time It can be expressed approximately as:

[0072] ;

[0073] Therefore, the remaining flight time for the aircraft to reach each path point is:

[0074] ;

[0075] In the formula, For the aircraft to arrive The remaining flight time for each waypoint, For the The arrival time of the waypoints, The current target path point number of the aircraft row;

[0076] The position error between the current position of the aircraft and each path point is as follows:

[0077] ;

[0078] in, For the The position error corresponding to the path point is For aircraft The latitude and longitude of the time, For the The latitude and longitude of the waypoints;

[0079] Step 4.3, construct a time matrix based on the remaining flight time corresponding to each path point, and construct a zero miss distance vector based on the position error corresponding to each path point, specifically:

[0080] Zero Miss Distance Vector for: ;

[0081] Time Matrix for:

[0082] ;

[0083] in, is the number of remaining path points, time matrix is a symmetric matrix, that is ;

[0084] Step 4.4, based on the time matrix and the zero miss distance vector, a set of Lagrange multiplier vectors are calculated, and the lateral acceleration of the aircraft during flight is calculated based on the Lagrange multiplier vectors. Finally, the energy consumption evaluation index is calculated based on the lateral acceleration. The specific process is as follows:

[0085] Based on time matrix , zero miss distance vector Calculate the Lagrange multiplier vector ,for:

[0086] ;

[0087] ;

[0088] In the formula, For the The Lagrange multiplier vector elements corresponding to the path points, is the transpose of the matrix;

[0089] Based on the Lagrange multiplier vector Calculate the lateral acceleration of the aircraft during flight Degrees, is:

[0090] ;

[0091] In the formula, For the The arrival time of each waypoint;

[0092] The energy consumption evaluation index is calculated based on the lateral acceleration:

[0093] ;

[0094] In the formula, is an energy consumption evaluation index. is the integration variable.

[0095] After calculating the energy consumption evaluation index of the initial trajectory corresponding to each individual in the current population, some individuals in the population with smaller energy consumption evaluation indexes (for example, 10% of the individuals in the population with smaller energy consumption evaluation indexes) can be selected for mutation and crossover operations, thereby generating a new generation of populations. Among them, the mutation operation refers to changing the values ​​of the control quantity sampling value, steering angle, safety distance of the security control area and / or angle penalty coefficient in the selected individual population, and the crossover operation refers to exchanging the values ​​of the control quantity sampling value, steering angle, safety distance of the security control area and / or angle penalty coefficient of the two selected individuals population. In step 5, the stopping criterion can be set to the number of iterations of the genetic algorithm reaching the preset number of iterations, or it can also be set to the convergence of the energy consumption evaluation index in the population. As for the specific implementation process of the genetic algorithm, it is a relatively well-known technical means, so it will not be repeated in this embodiment.

[0096] The following further illustrates the method for rapid planning of the minimum safe control area for a supersonic cruise target missile in this embodiment with reference to specific examples.

[0097] The map is selected as an area with a longitude range of 0-11° and a latitude range of 0-11°, and a grid size of 0.1°×0.1°, that is, Figure 3 As shown, Figure 3 The enclosed area in the map is the no-fly zone.

[0098] The initial simulation condition settings of the aircraft are shown in Table 1.

[0099] Table 1 Initial simulation conditions of aircraft

[0100]

[0101] The parameter value settings of the hybrid A* algorithm are shown in Table 2.

[0102] Table 2 Hybrid A* algorithm parameter settings

[0103]

[0104] On the initial path planned by the hybrid A* algorithm, 25 points are taken as path points for trajectory planning.

[0105] The parameter settings of the genetic algorithm are shown in Table 3.

[0106] Table 3 Genetic algorithm parameter settings

[0107]

[0108] Energy consumption evaluation index of the final trajectory planning result The value is 1113.67, which meets the constraints of heat flow, dynamic pressure, overload, etc. The final path planning results and the coordinates of the 25 selected path points are shown in Table 4.

[0109] Table 4 Path point coordinates

[0110]

[0111] It can be seen from Table 4 that the trajectory using the method of this embodiment satisfies the security zone constraints, and the path point coordinates basically coincide with the planned trajectory results, thereby effectively completing the trajectory planning of the aircraft.

[0112] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for rapid planning of the minimum safety control area of ​​a supersonic cruise target missile, characterized in that: The steps include: Step 1, establish the aircraft motion dynamics model and path constraints, and perform grid processing on the map to obtain a grid map, in which the initial value of the grid is 0, and the grids passed by and surrounded by the closed curve formed by the outer contour of the security control area are assigned a value of 1; Step 2, randomly selecting a number of parameter values ​​in the design space of the design variables of the trajectory planning as the initial population of the genetic algorithm, wherein the design variables include the control amount sampling value and the steering angle; Step 3, based on the grid map, the aircraft motion dynamics model and the path constraint, generating an initial trajectory corresponding to each individual in the current population based on a hybrid A* algorithm; Step 4, calculate the energy consumption evaluation index of the initial trajectory, and use the energy consumption evaluation index as the fitness function of the genetic algorithm to generate a new generation of population. The calculation process of the energy consumption evaluation index is: Step 4.1, take a number of path points on the initial path; Step 4.2, at the current moment Next, obtain the remaining flight time for the aircraft to reach each path point, and obtain the position error between the current position of the aircraft and each path point; Step 4.3, constructing a time matrix based on the remaining flight time corresponding to each path point, and constructing a zero miss distance vector based on the position error corresponding to each path point; Step 4.4, calculating a set of Lagrange multiplier vectors based on the time matrix and the zero miss distance vector, and calculating the lateral acceleration of the aircraft during flight based on the Lagrange multiplier vectors, and finally calculating the energy consumption evaluation index based on the lateral acceleration; Step 5: Determine whether the stopping criteria are met: If so, the initial trajectory with the minimum energy consumption evaluation index in the current population is taken as the final trajectory planning result and output; Otherwise, return to step 3.

2. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to claim 1 is characterized in that: In step 4.2, the remaining flight time for the aircraft to reach each path point is specifically: In the formula, For the aircraft to arrive The remaining flight time for each waypoint, For the The arrival time of the waypoints, is the total number of path points, The current target path point number of the aircraft row; The calculation process of the arrival time of the waypoint is: In the formula, The current moment of the aircraft and The relative great circle distance of the path points, is the speed of the aircraft, is the track inclination of the aircraft; The current target waypoint number of the aircraft row is defined as: in, For aircraft The longitude of the moment, For the The longitude of the waypoints, For the The longitude of the waypoint.

3. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to claim 2 is characterized in that: In step 4.3, the time matrix is ​​specifically: in, is the time matrix, is the number of remaining path points, is the total number of path points, The current target path point number of the aircraft.

4. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to claim 1, 2 or 3, characterized in that: In step 4.3, the zero miss distance vector is specifically: In the formula, is the zero miss distance vector, For the The position error corresponding to the path point is For aircraft The latitude and longitude of the time, For the The longitude and latitude of the waypoints, For the The arrival time of each waypoint.

5. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to claim 1, 2 or 3, characterized in that: The specific process of step 4.4 is as follows: The Lagrange multiplier vector is calculated based on the time matrix and the zero miss distance vector, which is: in, is the time matrix, is the zero miss distance vector, is the Lagrange multiplier vector, For the The Lagrange multiplier vector elements corresponding to the path points, is the total number of path points, is the transpose of the matrix; The lateral acceleration of the aircraft during flight is calculated based on the Lagrange multiplier vector: In the formula, is the lateral acceleration, , , , For the The arrival time of each waypoint; The energy consumption evaluation index is calculated based on the lateral acceleration and is: In the formula, is an energy consumption evaluation index. is the integration variable.

6. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to any one of claims 1 to 3, characterized in that: In step 2, the design variables also include the safety distance of the security control area and the angle penalty coefficient.

7. The method for rapid planning of the minimum safe control area of ​​a supersonic cruise target missile according to any one of claims 1 to 3, characterized in that: In step 5, the stopping criterion is reaching a preset number of iterations.

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