Wide-range adjustable gliding guidance method for hypersonic-speed maneuvering aircraft

Abstract

The invention discloses a wide-range adjustable gliding guidance method for a hypersonic-velocity maneuvering aircraft, and relates to the technical field of aircraft guidance. Performing remote longitudinal guidance based on an attack angle instruction and remote transverse guidance based on a heeling angle instruction by using a hybrid energy adjustment method; when short-range gliding guidance is carried out on the hypersonic aircraft, an attack angle instruction is set on a preset fixed attack angle profile, and pneumatic deceleration longitudinal guidance and pneumatic deceleration transverse guidance based on a heeling angle instruction are carried out by using a pneumatic deceleration gliding guidance method based on a D-V profile. According to the method, speed and height control weights are dynamically distributed in the remote stage to break through lift-drag ratio limitation, efficient deceleration and transverse constraint are achieved by combining a fixed attack angle profile and robust heeling angle symbol control in the short-range stage, and the core problems of range splitting, low energy management efficiency and insufficient terminal control precision in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of aircraft guidance technology, and in particular to a wide-range adjustable glide guidance method for hypersonic maneuvering aircraft. Background Technology

[0002] The primary range of a hypersonic vehicle lies in its glide phase, during which the vehicle glides solely under the combined influence of Earth's gravity and aerodynamics, and its mass remains constant. Simultaneously, it faces strict constraints regarding stagnation point heat flux density, overload, and structural loads. The main task of glide guidance is to achieve different range targets while satisfying multiple constraints, including process and terminal phases, guiding the vehicle to a pre-defined glide terminal window at appropriate speed and altitude.

[0003] In existing hypersonic vehicle glide guidance technologies, the tilt angle guidance method controls drag by fixing the angle of attack profile, adjusts altitude using the tilt angle amplitude, and controls lateral deviation using the sign. This method was previously used in reentry vehicles such as the Space Shuttle. However, lateral deviation relies on the switching control of the tilt angle sign, and its accuracy is limited by the lateral corridor design. When aerodynamic parameter deviations are large, it is difficult to ensure terminal heading alignment, and may even lead to misses. Furthermore, lateral turning efficiency is inversely proportional to flight speed; at low speeds, frequent tilt angle sign changes can easily cause trajectory oscillations, severely reducing longitudinal guidance accuracy. Therefore, this method is only suitable for the high-speed phase at Mach numbers greater than 2.

[0004] While angle-of-attack guidance methods can improve lateral accuracy, the angle of attack directly affects lift and drag, leading to strong coupling between altitude and speed control. For example, increasing the angle of attack can increase lift, but increased drag accelerates speed loss, and increased altitude leads to decreased dynamic pressure, which in turn weakens lift efficiency. This method needs to operate at the leading edge of the maximum lift-to-drag ratio angle of attack, relying on high lift-to-drag ratio aircraft designs with a flat lift-to-drag ratio curve, making it difficult to adapt to the long-range energy management requirements in complex aerodynamic environments.

[0005] The two methods described above exhibit a clear disconnect in range: short-range guidance is limited by lateral accuracy and dynamic response, making it difficult to meet the strict constraints of the terminal window; long-range guidance suffers from significant energy distribution contradictions, easily leading to unreachable range due to a decrease in lift-to-drag ratio. With the same engine providing the same energy and having the same terminal velocity, the total range must be adjustable over a wide range between the extreme long-range and short-range limits. This requires flexible trajectory and guidance system design. Current technology lacks a gliding guidance method that can cover a wide range while balancing process constraints and terminal accuracy. The following core issues urgently need to be addressed: how to maintain range reachability when the lift-to-drag ratio decreases and achieve efficient distribution of low-trajectory energy; and how to utilize aerodynamic drag to achieve rapid deceleration and precise terminal control without violating hard constraints such as heat flux and overload. Summary of the Invention

[0006] To address the above problems, this invention proposes a wide-range adjustable glide guidance method for hypersonic maneuvering vehicles. By integrating energy hybrid regulation and DV profile control mechanisms, it dynamically allocates speed and altitude control weights in the long-range phase to overcome lift-to-drag ratio limitations. In the short-range phase, it combines a fixed angle-of-attack profile with robust roll angle sign control to achieve efficient deceleration and lateral constraint. This solves the core problems of existing technologies, such as range fragmentation, inefficient energy management, and insufficient terminal control accuracy.

[0007] A wide-range adjustable glide guidance method for hypersonic maneuvering vehicles, the specific steps of which are as follows:

[0008] The actual range of the hypersonic vehicle is determined. If the actual range is greater than the preset range of the hypersonic vehicle, then when performing glide guidance on the hypersonic vehicle, a hybrid energy regulation method is used for long-range longitudinal guidance based on angle-of-attack commands and long-range lateral guidance based on tilt angle commands. The long-range longitudinal guidance dynamically allocates the long-range longitudinal guidance amount based on the kinetic and potential energy of the hypersonic vehicle, according to the flight altitude and flight speed. The long-range lateral guidance generates the long-range lateral guidance amount by the difference between the current trajectory deflection angle and the line-of-sight azimuth angle.

[0009] If the actual range is less than or equal to the preset range of the hypersonic vehicle, then when performing glide guidance on the hypersonic vehicle, the angle of attack command is set at a preset fixed angle of attack profile, and the aerodynamic deceleration glide guidance method based on the DV profile is used to perform aerodynamic deceleration longitudinal guidance and aerodynamic deceleration lateral guidance based on the tilt angle command; the aerodynamic deceleration longitudinal guidance achieves command tracking of flight altitude and drag acceleration by generating the amplitude of the tilt angle command; the aerodynamic deceleration lateral guidance uses the azimuth error as the error signal and adopts a switch control method to generate the sign of the tilt angle command.

[0010] Preferably, the long-range longitudinal guidance dynamically allocates the long-range longitudinal guidance amount of flight altitude and flight speed according to the kinetic and potential energy of the hypersonic vehicle. Specifically, it involves: obtaining a trajectory tracking guidance law for tracking altitude error based on the dynamic allocation ratio of the hypersonic vehicle's potential energy; obtaining a speed tracking guidance law for tracking speed error based on the dynamic allocation ratio of the hypersonic vehicle's kinetic energy; and combining the trajectory tracking guidance law and the speed tracking guidance law to obtain a hybrid energy regulation longitudinal guidance command for controlling the hypersonic maneuvering vehicle.

[0011] Preferably, the hybrid energy-regulated longitudinal guidance command is expressed as:

[0012] α c =α std (ΔL)+f(t)(α hc +α vc );

[0013] Where, α c Indicates a hybrid energy-regulated longitudinal guidance command; α std (ΔL) represents the nominal angle of attack obtained by interpolation of the profile α-ΔL based on the nominal trajectory, where α represents the angle of attack; ΔL represents the distance to be flown; f(t) represents the softening coefficient; α hc This represents the trajectory tracking guidance law; α vc This indicates the speed tracking guidance law.

[0014] Preferably, the trajectory tracking guidance law and the velocity tracking guidance law are expressed as follows:

[0015]

[0016] Among them, K h K represents the proportion of potential energy per unit mass to the total energy; v The proportion of kinetic energy per unit mass to the total energy is expressed by K. h and K v The allocation of long-range longitudinal guidance parameters to flight altitude and speed; Δh represents the altitude error signal; Represents the differential signal of altitude error; Δh i This represents the integral signal of altitude error. Indicates the proportional gain of a height; The proportional gain representing the acceleration / deceleration rate; Indicates high integral gain; The proportional gain represents the velocity; ΔV represents the velocity error. Represents the differential signal of velocity error; ΔV i This represents the integral signal of the speed error. The proportional gain represents the axial acceleration. Indicates the velocity integral gain; This indicates a high degree of tracking of the integral term; This represents the velocity tracking integral term.

[0017] Preferably, the altitude tracking integral term and the velocity tracking integral term satisfy the following conditions:

[0018]

[0019] in, express The calculation formula is And the amplitude is limited to -5° and 5°; express The calculation formula is And the amplitude is limited to -5° and 5°.

[0020] Preferably, the proportion of potential energy per unit mass to the total energy and the proportion of kinetic energy per unit mass to the total energy are expressed as follows:

[0021]

[0022] Where g represents gravitational acceleration; h represents flight altitude; V represents flight speed; and E represents total energy.

[0023] Preferably, the long-range lateral guidance generates the long-range lateral guidance amount based on the difference between the current ballistic deflection angle and the line-of-sight azimuth angle, specifically implemented as follows:

[0024] Calculate the difference between the current ballistic deviation angle and the line-of-sight azimuth angle to obtain the azimuth error;

[0025] By limiting the azimuth error signal, a continuous error signal for lateral guidance is obtained;

[0026] Based on the continuous error signal of lateral guidance, proportional feedback is used to obtain the lateral guidance law based on BTT maneuver. The rate of change of the tilt angle command output by the lateral guidance law is limited to obtain the long-range lateral guidance quantity.

[0027] Preferably, the preset fixed angle of attack profile is expressed in functional form as follows:

[0028]

[0029] Where, α std (V) represents the function form of a fixed angle of attack profile; α1 represents the angle of attack in the initial stage of gliding, α2 represents the angle of attack in the terminal stage of gliding, and α1 is greater than α2; V represents the flight speed; V1 and V2 represent two specific speed values, where V1 < V2.

[0030] Preferably, the amplitude of the tilt angle command is generated using a longitudinal tracking guidance law, and is expressed as:

[0031]

[0032] Where, σ c This indicates that the tilt angle guidance command generated using the longitudinal tracking guidance law is applied to σ. c The absolute value is used to obtain the amplitude of the yaw angle command; σ std (V) indicates the nominal tilt angle; Indicates the proportional gain of axial acceleration; a x Indicates axial acceleration signal; a xstd Indicates the nominal axial acceleration; Indicates the integral gain of axial acceleration; Indicates the height-ratio gain; h represents the height; Indicates the differential gain; hstd Indicates the nominal height; Indicates the rate of ascent and descent; Indicates the nominal acceleration and deceleration speed; This indicates the integral gain.

[0033] Preferably, the sign of the tilt angle command is generated using the azimuth error as the error signal and a switch control method. The specific algorithm implementation is as follows:

[0034] If |Δχ|>|Δχ c |and Δχ>0 and sign(σ) last =1, then sign(σ)←-1;

[0035] If |Δχ|>|Δχ c |and Δχ<0 and sign(σ) last =-1, then sign(σ)←1;

[0036] If |Δχ|>|Δχ c |And Δχ=0, then sign(σ)←sign(σ) last ;

[0037] If |Δχ|≤|Δχ c |, then sign(σ) ← sign(σ) last ;

[0038] Where Δχ represents the azimuth error; Δχ c This represents the azimuth angle in the lateral corridor corresponding to the current speed; |·| represents the absolute value; sign(σ) represents the sign of the roll angle, with "1" indicating a right roll and "-1" indicating a left roll; sign(σ) last The sign represents the tilt angle at the previous moment; ← indicates assignment.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] This invention proposes a wide-range adjustable glide guidance method for hypersonic maneuvering vehicles. By integrating energy hybrid regulation and DV profile control mechanisms, it dynamically allocates speed and altitude control weights in the long-range phase to overcome lift-to-drag ratio limitations. Based on energy control principles, the authority for speed and altitude is redistributed, efficiently leveraging the high lift-to-drag ratio glide characteristics of hypersonic vehicles. In the short-range phase, it combines a fixed angle-of-attack profile with robust roll sign control to achieve efficient deceleration and lateral constraint, solving the core problems of existing technologies such as range fragmentation, inefficient energy management, and insufficient terminal control accuracy. Attached Figure Description

[0041] The present invention will now be described in further detail with reference to the accompanying drawings;

[0042] Figure 1 This is a schematic diagram of a wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle according to an embodiment of the present invention.

[0043] Figure 2 Force analysis diagram of the aircraft mass point based on the principle of tilt angle amplitude control of mass trajectory in the wide-range adjustable glide guidance method of hypersonic maneuvering aircraft according to an embodiment of the present invention;

[0044] Figure 3 Force analysis diagram of the aircraft mass point based on the principle of angle-of-attack control mass trajectory of the wide-range adjustable glide guidance method for hypersonic maneuvering aircraft in an embodiment of the present invention.

[0045] Figure 4 This is a gliding corridor diagram showing the maximum lift-to-drag ratio angle of attack altitude-velocity profile of the wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to an embodiment of the present invention.

[0046] Figure 5 This is a glide corridor diagram showing the maximum lift-to-drag ratio, angle of attack, drag acceleration-velocity profile, and glide corridor of the wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to an embodiment of the present invention.

[0047] Figure 6 This is a height-velocity profile glide corridor diagram at an angle of attack of 24° for a wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle according to an embodiment of the present invention.

[0048] Figure 7 This is a drag acceleration-velocity profile glide corridor diagram at an angle of attack of 24° for a wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle according to an embodiment of the present invention.

[0049] Figure 8 This is a block diagram of the energy mixing and adjustment guidance structure of the wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to an embodiment of the present invention;

[0050] Figure 9 This is a structural diagram of the energy mixing and adjustment longitudinal guidance law of the wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to an embodiment of the present invention;

[0051] Figure 10 This is a block diagram of the DV profile aerodynamic deceleration guidance structure of the wide-range adjustable glide guidance method for hypersonic maneuvering aircraft according to an embodiment of the present invention.

[0052] Figure 11 This is a schematic diagram of the nominal angle of attack of a wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle according to an embodiment of the present invention.

[0053] Figure 12 This is a structural diagram of the longitudinal guidance law for the wide-range adjustable glide guidance method of a hypersonic maneuvering vehicle according to an embodiment of the present invention, using the DV profile aerodynamic deceleration method.

[0054] Figure 13 This is a schematic diagram of the transverse corridor for a wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle according to an embodiment of the present invention. Detailed Implementation

[0055] The present invention will be further described below through specific embodiments.

[0056] Figure 1 This invention relates to the specific principle of the wide-range adjustable glide guidance method for hypersonic maneuvering vehicles, including quantitative analysis of the glide corridor DV profile (drag acceleration-velocity profile) and hV profile. Based on the results of the quantitative analysis, a wide-range adjustable glide guidance method for hypersonic maneuvering vehicles is proposed.

[0057] Quantitative analysis of the DV and hV profiles of the glide corridor for hypersonic vehicles is as follows:

[0058] The equation of motion for a hypersonic vehicle during the glide phase is expressed in the ballistic (track) coordinate system O. b x k y k z k The equations of motion for the center of mass in 3DOF are obtained and expressed as follows:

[0059]

[0060] In the formula, V represents the magnitude of the flight speed, γ is the local ballistic inclination angle, χ is the azimuth angle, σ is the roll angle, r is the geocentric distance, m is the mass of the spacecraft, μ is the Earth's gravitational constant, and longitude and geocentric latitude are represented by λ and φ, respectively. The control variables are the angle of attack α and sideslip angle β, which affect the thrust component, lift L, and drag D in the trajectory coordinate system.

[0061] Gliding flight involves complex force and thermal environments, thus imposing strict process constraints on certain states. Specifically, the following constraints need to be considered:

[0062] Body normal overload constraint:

[0063] The main load-bearing components of an aircraft have certain strength limitations. If the structural load exceeds the strength margin, the aircraft structure will suffer damage and fracture, and in severe cases, it may disintegrate in mid-air. The gliding phase is an unpowered phase, where the main source of overload is aerodynamics. The primary constraint is the normal overload of the aircraft system, and since there are no longer engine limitations, it has a greater upper limit.

[0064]

[0065] Stagnant heat flux density:

[0066] Since aerodynamic heating is the cumulative effect of heat flux density over time, for short-range ballistic missiles with shorter flight times, It has a higher tolerance for peak values.

[0067]

[0068] Control surface load constraints:

[0069] Besides the leading-edge extensions of the forebody, the aerodynamic forces during flight primarily act on the two horizontal control surfaces. When the dynamic pressure is too high, the control surfaces will bear significant aerodynamic loads, posing a huge challenge to the structural strength of the connection between the control shaft and the fuselage. Here, the load on the control surfaces is constrained in the form of bending moments, and trimmed control deflection is used instead of actual control deflection, expressed as:

[0070]

[0071] In addition to meeting the above process constraints, as shown in Table 1, glide guidance also requires guiding the aircraft to the terminal guidance window at a certain speed and altitude, while eliminating lateral range error, as shown in Table 1:

[0072] Table 1: Parameters for gliding guidance.

[0073]

[0074] The aerodynamic guidance principle of hypersonic vehicles is introduced below:

[0075] Aerodynamic vector F a The projection in the track coordinate system can be expressed as:

[0076] (F a ) k =[D,Lcosσ,Lsinσ] T ;

[0077] The angle of attack α directly changes the drag D, thus affecting flight speed. Furthermore, the magnitude of drag is also directly related to the density at the current altitude. Figure 2 and Figure 3 As shown, the projection of lift L onto the longitudinal plane affects the aircraft's normal acceleration, thus adjusting its altitude; the tilt component of lift, Lsinσ, can generate a lateral acceleration component in the horizontal plane, further controlling lateral motion. The magnitude of lift is also related to the angle of attack α. Therefore, during gliding, the angle of attack α and the tilt angle σ can be used to control the motion of the 3DOF center of mass.

[0078] Therefore, two methods have been developed for controlling the longitudinal trajectory: one is to tilt the total lift, adjusting the lift component in the longitudinal plane by varying the amplitude of the tilt angle; the other is to directly change the angle of attack to adjust the aerodynamic lift in the longitudinal plane. Correspondingly, there are also two methods for controlling the lateral trajectory; the former can be pre-designed, such as... Figure 8 The funnel-shaped transverse corridor shown χ c (V) When the azimuth error Δχ exceeds the range specified for the corridor, i.e. Δχ ≥ Δχ c (V) By changing the sign of the roll angle, the direction of the lift in the horizontal plane is adjusted, thereby changing the lateral stroke; the latter can eliminate lateral error by adjusting the amplitude of the roll angle within a small range and using BTT maneuvers.

[0079] The glide corridor of hypersonic vehicles is analyzed below:

[0080] Setting the second term of the equation of motion for the hypersonic vehicle during the glide phase to zero, the equilibrium glide condition is expressed as:

[0081]

[0082] In the formula, This is an additional term for Coriolis acceleration and centrifugal acceleration. Generally, Since the magnitude is relatively small, and cosγ≈1, this equation can be transformed into a quasi-equilibrium gliding (QEGC) condition, resulting in:

[0083]

[0084] Using the three state constraints of a hypersonic vehicle, the lower bound of the glide corridor can be calculated by the intersection of the constraints that the vehicle must satisfy for safe gliding.

[0085] First, the gliding corridor with the height-velocity (hV) profile is obtained, represented as:

[0086]

[0087] The upper boundary of the gliding corridor is determined by the QEGC condition. Taking the QEGC condition boundary corresponding to zero tilt angle, it is expressed as:

[0088]

[0089] Note h QEGC Solving these equations requires numerical iteration. Based on these two formulas, the gliding corridor is also related to the design of the angle-of-attack profile.

[0090] Therefore, the gliding corridor of the hV profile can be represented as:

[0091]

[0092] In the formula, h up (V) and h down (V) represent the upper and lower boundaries of the gliding corridor in the hV profile, respectively.

[0093] Similarly, the DV profile can be calculated and represented as:

[0094]

[0095] Calculating the drag acceleration under QEGC conditions requires h QEGC Thus, the gliding corridor of the DV profile is obtained, represented as:

[0096]

[0097] To obtain the maximum gliding range, the following is given based on the maximum lift-to-drag ratio angle of attack α. K,max and maximum heat flux density The determined hV and DV profiles are as follows: Figure 4 and Figure 5 As shown. Based on the changing trend of the gliding corridor, it can be found that: in the early stage of gliding, heat flux density is the main constraint; as the speed decreases, overload gradually becomes the main factor; and when the altitude decreases further, the control surface load constraint and the heat flux density boundary will intersect.

[0098] The differential equation for the trajectory length s of the supplementary aircraft is as follows. When the transverse stroke is small, it can represent the range of the aircraft, expressed as:

[0099]

[0100] Integrating this equation, when the trajectory inclination angle is small, sinγ≈0, we can obtain the longitudinal range of the glide segment:

[0101]

[0102] Therefore, the DV profile has practical physical significance: when the trajectory inclination changes relatively little, its direct integration can estimate the range of the glide segment. Furthermore, it is derived that the boundary condition corresponding to the QEGC condition represents the maximum glide segment range.

[0103] exist Figure 5 With an initial velocity of V0 = 2298.4 m / s, and V f =1100m / s is the terminal velocity. Integrating along the QEGC boundary, the maximum gliding range αs is obtained. f=709.6km. Without tilting maneuvers, i.e., σ = 0°, this just exceeds the 673km gliding range requirement. Considering parameter deviations, primarily lift-to-drag ratio, reaching the target point may be impossible. Therefore, a prerequisite for using tilting angle guidance is being above the QEGC boundary corresponding to zero tilting angle in the DV profile, with a certain margin. Thus, for long-range gliding guidance, tilting angle cannot be used for guidance; the potential of angle-of-attack guidance must be fully explored.

[0104] Using a large angle of attack profile can effectively reduce the amplitude of the tilt angle. Figure 6 and Figure 7 Given a gliding corridor with α = 24°, the maximum heat flux density constraint is: for Figure 6 In the hV profile shown, the zero-tilt QEGC boundary corresponding to the large angle of attack shifts upwards; due to the release of the heat flux density constraint, the overload boundary becomes the main constraint, and the overload boundary also shifts approximately upwards. Therefore, the range of the gliding corridor enveloped by both changes relatively little. The QEGC boundary corresponding to σ=76° shifts significantly downwards, exacerbating the narrowing of the gliding corridor.

[0105] Figure 7 The DV profile shown at α = 24° is also primarily constrained by the QEGC and overload boundary. The thermal flux constraint is located above the load boundary and is therefore not shown in the figure. σ = 76° results in a lower gliding altitude, causing greater aerodynamic drag compared to the QEGC at zero tilt angle. At this point, σ = 76° corresponds to Δs. f =126.128km. Compared to the maximum lift-to-drag ratio angle of attack, the billet angle amplitude is reduced by 4°. The maximum range at the QEGC boundary corresponding to zero billet angle is Δsf = 543.017km, which is 166km less than that at the maximum lift-to-drag ratio angle of attack. The minimum limiting range is 16.2km, equivalent to σ = 84°. Therefore, the high angle of attack profile provides an additional 5° margin in terms of billet angle guidance commands.

[0106] Based on the quantitative analysis of the DV and hV profiles of the glide corridor, the following issues were identified: The 673km glide range is at the upper limit of the aircraft's capability, constrained by the QEGC boundary, making it impossible to utilize tilt angle guidance. Therefore, how to adjust the angle of attack to obtain a greater lift-to-drag ratio under conditions of lift-to-drag ratio deviation, enabling the aircraft to glide further, has become the main problem for long-range target glide guidance. Conversely, the 112km glide range is at the lower limit of the aircraft's capability, with the main constraints being overload and heat flux density boundaries. How to fully utilize drag for efficient aerodynamic deceleration while preventing excessive lateral deviation from the target point is the main challenge for short-range glide guidance. Therefore, the core issue for tunable guidance with a wide range in the glide phase is how to utilize a large lift-to-drag ratio to obtain a longer glide range, and how to utilize aerodynamics for efficient aerodynamic deceleration without violating constraints.

[0107] Based on the quantitative analysis of the DV and hV profiles of the glide corridor, a wide-range adjustable glide guidance method for hypersonic maneuvering vehicles is proposed, including a long-range glide guidance method based on energy mixing regulation and a short-range aerodynamic deceleration glide guidance method based on the DV profile. The specific steps are as follows:

[0108] The actual range of the hypersonic vehicle is determined. If the actual range is greater than the preset range of the hypersonic vehicle, then during glide guidance, a hybrid energy regulation method is used for long-range longitudinal guidance based on angle-of-attack commands and long-range lateral guidance based on tilt angle commands. The long-range longitudinal guidance dynamically allocates the longitudinal guidance quantity based on the kinetic and potential energy of the hypersonic vehicle to the flight altitude and flight speed. The long-range lateral guidance generates the long-range lateral guidance quantity through the difference between the current trajectory deflection angle and the line-of-sight azimuth angle. If the actual range is less than... If the range is equal to the preset range of the hypersonic vehicle, then when performing glide guidance on the hypersonic vehicle, the angle of attack command is set on a preset fixed angle of attack profile. The aerodynamic deceleration glide guidance method based on the DV profile is used to perform aerodynamic deceleration longitudinal guidance and aerodynamic deceleration lateral guidance based on the tilt angle command. The aerodynamic deceleration longitudinal guidance achieves command tracking of flight altitude and drag acceleration by generating the amplitude of the tilt angle command. The aerodynamic deceleration lateral guidance uses the azimuth error as the error signal and adopts a switch control method to generate the sign of the tilt angle command.

[0109] Specifically, long-range gliding guidance methods based on energy mixing and regulation include energy mixing and regulation longitudinal guidance and energy mixing and regulation lateral guidance.

[0110] Energy mixing regulation longitudinal guidance:

[0111] The main idea of ​​energy hybrid regulation guidance is to achieve the maximum lift-to-drag ratio at the angle of attack α. K,amxAdjusting the angle of attack nearby alters the lift-drag characteristics of the aircraft, thereby enabling command tracking of altitude and speed, such as... Figure 8 As shown. However, for the longitudinal guidance system, it is in an underactuated state, meaning that only the angle of attack is the single control variable. To solve this underactuated guidance problem, the guidance quantities for altitude and speed are dynamically allocated, incorporating the concept of total energy control. In the lateral passage, heading alignment is achieved by controlling small-amplitude BTT maneuvers.

[0112] The total energy is expressed as:

[0113]

[0114] Based on the ratio of kinetic energy to potential energy, the dynamic distribution coefficient is obtained, expressed as:

[0115]

[0116] In the formula, K h and K v These represent the proportions of potential energy and kinetic energy per unit mass of the total energy, respectively, and also correspond to the guidance allocation weights for altitude and velocity. Since the altitude change during the gliding phase is relatively small, g can be fixed here as the gravitational acceleration corresponding to the intermediate altitude. The range problem in long-range gliding is the main challenge; therefore, the longitudinal nominal profile of energy-mixed regulation guidance is chosen as: altitude-distance to be flown (h-ΔL) and velocity-distance to be flown (V-ΔL).

[0117] Wherein, the waiting distance ΔL is defined as the difference between the nominal trajectory terminal distance and the current distance, expressed as:

[0118] ΔL(t)=s f -s(t);

[0119] The longitudinal tracking guidance law is given in the form of full-state linear feedback of velocity V and altitude h. In essence, controlling flight altitude is about maintaining the current environmental density ρ; velocity control is about adjusting drag acceleration. To reduce overshoot and improve system damping, differential signals are added respectively. and Feedback; in order to eliminate control steady error and ensure the tracking accuracy of altitude and speed, their integral terms are introduced.

[0120] Differential signal of height Let V be the acceleration or deceleration, and let V be the velocity vector. r In the track coordinate system y k Projection of the axis.

[0121]

[0122] Strictly speaking, the differential signal of velocity It is along the x-axis of the track coordinate system k The acceleration, i.e., the drag acceleration a x,v When the angle of attack is small, the axial acceleration 'a' of the fuselage axis can be selected. x Substitution. Therefore, the error signal is:

[0123]

[0124] In the formula, the nominal height h std Speed ​​V std Ballistic inclination angle γ std and axial acceleration a xstd The distance ΔL to be flown can be obtained by piecewise linear interpolation based on the nominal trajectory of the gliding segment.

[0125] Because the pull-up altitude is related to the engine thrust state, and there may be uncertainties such as density and lift-to-drag ratio, the actual flight state may deviate significantly from the initial state of the nominal trajectory. This can result in large control inputs, potentially causing significant overshoot and affecting subsequent guidance accuracy; it could even lead to control saturation and nonlinear instability. Therefore, when calculating the actual error signal, it is necessary to perform amplitude limiting processing.

[0126]

[0127] It is important to note that in digital flight control computers, due to system characteristics and computational accuracy issues, system deviations always exist, potentially leading to excessively large integral terms. To mitigate this problem, effective amplitude limiting and authority allocation are required for each part of the control signal, as shown below:

[0128]

[0129] in, and For integral gain, This indicates a high degree of tracking of the integral term; This represents the velocity tracking integral term. express The calculation formula is And the amplitude is limited to -5° and 5°; express The calculation formula is Furthermore, the amplitude is limited to -5° and 5°. A dead-zone operator is introduced into the error term to be integrated for separation, expressed as:

[0130]

[0131] Therefore, considering the corresponding energy distribution coefficient, the trajectory tracking guidance law α based on altitude error feedback during the gliding phase can be obtained. hcand velocity tracking guidance law α vc , represented as:

[0132]

[0133] Among them, K h K represents the proportion of potential energy per unit mass to the total energy; v The proportion of kinetic energy per unit mass to the total energy is expressed by K. h and K v The allocation of long-range longitudinal guidance parameters to flight altitude and speed; Δh represents the altitude error signal; Represents the differential signal of altitude error; Δh i This represents the integral signal of altitude error. Indicates the proportional gain of a height; The proportional gain representing the acceleration / deceleration rate; Indicates high integral gain; The proportional gain represents the velocity; ΔV represents the velocity error. Represents the differential signal of velocity error; ΔV i This represents the integral signal of the speed error. The proportional gain represents the axial acceleration. This represents the velocity integral gain. In addition, to ensure a smooth transition of guidance commands within the initial 2 seconds of the guidance stage transition, softening processing is required. Here, a parabolic softening coefficient f(t) is used, with the following specific form:

[0134]

[0135] The hybrid energy-regulated longitudinal guidance command α is obtained. c :

[0136] α c =α std (ΔL)+f(t)(α hc +α vc );

[0137] In the formula, α std (ΔL) is the nominal angle of attack obtained by interpolation based on the profile α-ΔL of the nominal trajectory. The angle of attack command is then subjected to amplitude limiting processing to obtain the following result: Figure 9 The structure of the longitudinal guidance law is shown.

[0138] α c =sat(α) c (5°, 25°);

[0139] Energy mixing and regulation lateral guidance:

[0140] Because the aircraft is equipped with only a single rudder and has a symmetrical shape, its ability to utilize STT maneuvers in dive guidance is limited. Therefore, another task of gliding guidance is to utilize the advantage of long-duration gliding to gradually eliminate terminal lateral deviation and alleviate the pressure of lateral alignment in terminal guidance. The lateral control principle of the hybrid energy conditioning guidance method is: to achieve heading alignment through small-range BTT maneuvers, reducing the azimuth error Δχ. This is based on the current ballistic deflection angle χ. k And line of sight azimuth χ los The difference generates the lateral guidance quantity, where the line-of-sight angle is calculated using the following formula:

[0141] Δχ=χ k -χ los ;

[0142] In addition, the error signal needs to be appropriately limited, thus obtaining the continuous error signal for transverse guidance, expressed as:

[0143] Δχ=sat(χ k -χ los (-5°, 5°);

[0144] Using proportional feedback, the lateral guidance law based on BTT maneuver can be obtained:

[0145] σ=sat(k χ Δχ, -10°, 10°);

[0146] In addition, to reduce the impact of motion coupling, the rate of change of the tilt angle command is limited:

[0147]

[0148] The following is a short-range aerodynamic deceleration glide guidance method based on DV profile, including aerodynamic deceleration longitudinal guidance and aerodynamic deceleration lateral guidance, specifically:

[0149] like Figure 10 As shown, the angle of attack command α std Designed with a pre-defined fixed profile, it aims to achieve efficient aerodynamic deceleration using a large angle of attack. For longitudinal guidance, the amplitude of the aircraft's tilt angle σ is adjusted to control altitude h and drag acceleration a. x Command tracking; in lateral guidance, the sign σ of the tilt angle is changed by the constraint of the lateral corridor to reduce the terminal azimuth error.

[0150] Nominal angle of attack profile:

[0151] The nominal angle-of-attack profile of the aerodynamic deceleration and guidance method based on the DV profile is parameterized as a piecewise linear function α of the velocity. std (V), the specific functional relationship is expressed in the form of a reverse half-funnel as follows:

[0152]

[0153] α1 represents the angle of attack in the initial stage of gliding, α2 represents the angle of attack in the terminal stage of gliding, and α1 is greater than α2; V represents the flight speed; V1 and V2 represent two specific speed values, where V1 < V2.

[0154] like Figure 11 As shown, a small angle of attack α2 is used at the beginning of the gliding phase. As the speed decreases, the angle of attack increases linearly to a constant value α1 and remains until the terminal speed.

[0155] The reason why the angle of attack increases as the speed decreases is as follows:

[0156] (1) Highly efficient aerodynamic deceleration. The flight time of 112km glide is relatively short. Therefore, within the limited flight time, effective aerodynamic deceleration is achieved by increasing the angle of attack to generate a greater drag coefficient, so that the flight speed meets the design requirements when the aircraft reaches the terminal glide window.

[0157] (2) Strong lateral control capability. The guidance method for short-range glide is to control the heading by changing the sign of the roll angle. The greater the aerodynamic lift, the greater the lateral component of the lift in the track coordinate system when the aircraft rolls, which is beneficial to ensuring the heading control authority of the flight and achieving rapid turns.

[0158] (3) Overload constraints must be met. The dynamic pressure is relatively high in the initial stage of gliding, and an excessive angle of attack may cause the normal overload to exceed the constraint. As the speed decreases, the effect of the overload constraint weakens, and a larger angle of attack can be used.

[0159] Aerodynamic deceleration longitudinal guidance:

[0160] like Figure 12 As shown, the aerodynamic deceleration guidance method based on the DV profile employs a perturbation method to design the nominal trajectory tracker, and the guidance law is a PID feedback control, expressed as follows:

[0161]

[0162] In the formula, σ c This is a tilt angle guidance command. For feedback gain coefficient; subscript std This represents the standard ballistic parameters obtained by interpolating the nominal state-velocity profile based on the current velocity V. Similarly, the amplitudes of each control component need to be limited, and the integral needs to be desaturated. Specifically, σ... std (V) indicates the nominal tilt angle; Indicates the proportional gain of axial acceleration; a x Indicates axial acceleration signal; a xstdIndicates the nominal axial acceleration; Indicates the integral gain of axial acceleration; Indicates the height-ratio gain; h represents the height; Indicates the differential gain; h std Indicates the nominal height; Indicates the rate of ascent and descent; Indicates the nominal acceleration and deceleration speed; This indicates the integral gain.

[0163] The longitudinal guidance law needs to track the nominal flight profile to ensure that the glide trajectory meets the glide corridor constraints and satisfies the requirements for flight speed and altitude at the end of the glide. This is achieved by using a fixed angle-of-attack profile α. std (V), therefore the lift-to-drag ratio is relatively fixed. The guidance law uses the drag acceleration D / m to track the velocity change of the nominal trajectory, thereby achieving the effect of controlling the terminal velocity. The axial acceleration signal a is used. x The drag acceleration is approximated in the velocity coordinate system. Since the drag coefficient is fixed and cannot be adjusted, the principle of controlling drag acceleration using the roll angle amplitude is to change the dynamic pressure by altering the flight altitude, thereby indirectly adjusting the drag acceleration. Therefore, when the drag acceleration is less than the nominal value, the flight altitude needs to be reduced to obtain a greater increase in dynamic pressure (D / m). The relationship between flight altitude and roll angle can be obtained through the following derivation.

[0164] Force analysis of spacecraft particles Figure 2 It can be seen that when the amplitude of the aircraft's roll angle σ changes, the lift L tilts, and its component Lcosσ in the longitudinal plane changes accordingly, thus altering the aircraft's longitudinal acceleration and affecting the second derivative of altitude. Similarly, according to Figure 2 The longitudinal acceleration of the aircraft can be derived. The expression:

[0165]

[0166] It can be seen from this formula that, The tilt angle is linearly correlated with cosσ, and its magnitude can change the longitudinal acceleration of the aircraft. Therefore, the lifting speed can be directly controlled by |σc|. This allows for altitude adjustment. However, altitude control using the roll angle has a certain lag. Therefore, when designing the longitudinal guidance law, it is necessary to select an appropriate feedback gain to compensate for the dynamic response characteristics.

[0167] Pneumatic deceleration lateral guidance:

[0168] Longitudinal guidance for aerodynamic deceleration based on the DV profile only requires controlling the amplitude of the tilt angle |σc There are no requirements regarding the direction of the tilt. Therefore, the sign of the tilt angle (σ) is chosen for lateral guidance. c This serves as the guidance command. When lift tilts, the lateral component causes the aircraft's course to deviate from the target point. To ensure the alignment accuracy of the course at the end of the glide phase, lateral guidance employs a method based on... Figure 13 The tilt angle reversal logic of the transverse corridor shown is as follows: using the azimuth error as the error signal, a switch control method is used to determine the tilt direction. The specific algorithm is shown in Table 2, where "1" indicates right tilt and "-1" indicates left tilt.

[0169] Table 2: Tilt Angle Sign Switching Control Algorithm

[0170]

[0171] Therefore, the final tilt angle guidance command is obtained, expressed as:

[0172] σ c =|σ c |sign(σ c );

[0173] Horizontal corridor form such as Figure 13 As shown, this is a funnel-shaped piecewise function relating azimuth error to velocity, which gradually narrows as velocity decreases. The width of the lateral corridor is mainly determined by flight speed and lateral maneuverability. If the corridor is too narrow, the number of roll angle reversals increases, increasing the risk to attitude control and hindering longitudinal trajectory tracking; if the corridor is too wide, the terminal heading alignment accuracy is poor.

[0174] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A wide-range adjustable glide guidance method for a hypersonic maneuvering vehicle, characterized in that, Includes the following steps: The actual range of the hypersonic vehicle is determined. If the actual range is greater than the preset range of the hypersonic vehicle, then when performing glide guidance on the hypersonic vehicle, a hybrid energy regulation method is used for long-range longitudinal guidance based on angle-of-attack commands and long-range lateral guidance based on tilt angle commands. The long-range longitudinal guidance dynamically allocates the long-range longitudinal guidance amount based on the kinetic and potential energy of the hypersonic vehicle, according to the flight altitude and flight speed. The long-range lateral guidance generates the long-range lateral guidance amount by the difference between the current trajectory deflection angle and the line-of-sight azimuth angle. If the actual range is less than or equal to the preset range of the hypersonic vehicle, then when performing glide guidance on the hypersonic vehicle, the angle of attack command is set at a preset fixed angle of attack profile, and the aerodynamic deceleration glide guidance method based on the DV profile is used to perform aerodynamic deceleration longitudinal guidance and aerodynamic deceleration lateral guidance based on the tilt angle command; the aerodynamic deceleration longitudinal guidance achieves command tracking of flight altitude and drag acceleration by generating the amplitude of the tilt angle command; the aerodynamic deceleration lateral guidance uses the azimuth error as the error signal and adopts a switch control method to generate the sign of the tilt angle command.

2. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The long-range longitudinal guidance dynamically allocates the long-range longitudinal guidance amount to flight altitude and flight speed based on the kinetic and potential energy of the hypersonic vehicle. Specifically, it obtains a trajectory tracking guidance law to track altitude errors based on the dynamic allocation ratio of the hypersonic vehicle's potential energy; it obtains a speed tracking guidance law to track speed errors based on the dynamic allocation ratio of the hypersonic vehicle's kinetic energy; and it combines the trajectory tracking guidance law and the speed tracking guidance law to obtain a hybrid energy regulation longitudinal guidance command for controlling the hypersonic maneuvering vehicle.

3. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The hybrid energy-regulated longitudinal guidance command is expressed as follows: a c =a std (ΔL)+f(t)(a) hc +a vc ); Where, α c Indicates a hybrid energy-regulated longitudinal guidance command; α std (ΔL) represents the nominal angle of attack obtained by interpolation of the profile α-ΔL based on the nominal trajectory, where α represents the angle of attack; ΔL represents the distance to be flown; f(t) represents the softening coefficient; α hc This represents the trajectory tracking guidance law; α vc This indicates the speed tracking guidance law.

4. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 3, characterized in that, The trajectory tracking guidance law and the velocity tracking guidance law are expressed as follows: Among them, K h K represents the proportion of potential energy per unit mass to the total energy; v The proportion of kinetic energy per unit mass to the total energy is expressed by K. h and K v The allocation of long-range longitudinal guidance parameters to flight altitude and speed; Δh represents the altitude error signal; Represents the differential signal of altitude error; Δh i This represents the integral signal of altitude error. Indicates the proportional gain of a height; The proportional gain representing the acceleration / deceleration rate; Indicates high integral gain; The proportional gain represents the velocity; ΔV represents the velocity error. Represents the differential signal of velocity error; ΔV i This represents the integral signal of the speed error. The proportional gain represents the axial acceleration. Indicates the velocity integral gain; This indicates a high degree of tracking of the integral term; This represents the velocity tracking integral term.

5. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 4, characterized in that, The altitude tracking integral term and the velocity tracking integral term satisfy the following conditions: in, express The calculation formula is And the amplitude is limited to -5° and 5°; express The calculation formula is And the amplitude is limited to -5° and 5°.

6. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 4, characterized in that, The proportion of potential energy per unit mass to the total energy and the proportion of kinetic energy per unit mass to the total energy are expressed as follows: Where g represents gravitational acceleration; h represents flight altitude; V represents flight speed; and E represents total energy.

7. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The long-range lateral guidance generates a long-range lateral guidance amount based on the difference between the current ballistic deflection angle and the line-of-sight azimuth angle, specifically implemented as follows: Calculate the difference between the current ballistic deviation angle and the line-of-sight azimuth angle to obtain the azimuth error; By limiting the azimuth error signal, a continuous error signal for lateral guidance is obtained; Based on the continuous error signal of lateral guidance, proportional feedback is used to obtain the lateral guidance law based on BTT maneuver. The rate of change of the tilt angle command output by the lateral guidance law is limited to obtain the long-range lateral guidance quantity.

8. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The preset fixed angle of attack profile is expressed in functional form as follows: Where, α std (V) represents the function form of a fixed angle of attack profile; α1 represents the angle of attack in the initial stage of gliding, α2 represents the angle of attack in the terminal stage of gliding, and α1 is greater than α2; V represents the flight speed; V1 and V2 represent two specific speed values, where V1 < V2.

9. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The amplitude of the tilt angle command is generated using the longitudinal tracking guidance law and is expressed as: Where, σ c This indicates that the tilt angle guidance command generated using the longitudinal tracking guidance law is applied to σ. c The absolute value is used to obtain the amplitude of the yaw angle command; σ std (V) indicates the nominal tilt angle; Indicates the proportional gain of axial acceleration; a x Indicates axial acceleration signal; a xstd Indicates the nominal axial acceleration; Indicates the integral gain of axial acceleration; Indicates the height-ratio gain; h represents the height; Indicates the differential gain; h std Indicates the nominal height; Indicates the rate of ascent and descent; Indicates the nominal acceleration and deceleration speed; This indicates the integral gain.

10. The wide-range adjustable glide guidance method for hypersonic maneuvering vehicles according to claim 1, characterized in that, The sign of the tilt angle command is generated using the azimuth error as the error signal and a switching control method. The specific algorithm implementation is as follows: If |Δχ| > |Δχ c | and Δχ > 0 and sign(σ) last = 1, then sign(σ) ← -1; If |Δχ| > |Δχ c | and Δχ < 0 and sign(σ) last = -1, then sign(σ) ← 1; If|Dx|>|Dx c |And Δx=0,then sign(σ)←sign(σ) last ; If |Δχ| ≤ |Δχ c |, then sign(σ) ← sign(σ) last ; Where Δχ represents the azimuth error; Δχ c This represents the azimuth angle in the lateral corridor corresponding to the current speed; |·| represents the absolute value; sign(σ) represents the sign of the roll angle, with "1" indicating a right roll and "-1" indicating a left roll; sign(σ) last The sign represents the tilt angle at the previous moment; ← indicates assignment.

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