A high-order sliding mode extended state observer based maneuvering target attack angle constraint guidance method
Patent Information
- Application Number
- CN202611170017.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-04
- Publication Date
- 2026-10-30
AI Technical Summary
[0006]本发明的目的在于提供一种基于高阶滑模扩张状态观测器的机动目标攻击角约束制导方法，用以解决未知机动目标拦截过程中攻击角控制精度不足、扰动补偿能力弱以及传统滑模制导指令峰值和波动较大的问题
[0015]第一，本发明将目标机动、模型不确定性和外界扰动统一为总扰动，并通过高阶滑模扩张状态观测器进行实时估计，能够提高未知机动目标场景下的抗扰能力。
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Figure CN123010778A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aircraft guidance and control technology, and particularly relates to a maneuvering target attack angle constraint guidance method based on a high-order sliding mode extended state observer. Background Technology
[0002] With the development of precision guidance technology and modern defense systems, the terminal guidance mission of missiles has gradually shifted from the traditional method of accurately hitting the target to accurately hitting the target according to the desired terminal state. For hardened targets, armored targets, ship targets, and targets with directional protection capabilities, missiles need to enter the target at a specific angle of attack to improve the energy utilization efficiency of the warhead and the damage effect.
[0003] Existing attack angle constraint guidance methods typically achieve terminal angle control through virtual targets, remaining flight time estimation, variable gain guidance, and fixed-time error dynamics. These methods achieve good results with stationary or weakly maneuvering targets, but when the target has strong unknown maneuvers, the target acceleration and model uncertainty directly affect the line-of-sight angular rate dynamics, thereby reducing the accuracy of terminal attack angle control.
[0004] On the other hand, some existing methods rely on relatively accurate model information, remaining flight time estimates, or small angle assumptions, making them susceptible to sensor errors, target penetration maneuvers, and actuator constraints in engineering applications. If only the high-gain switching term in traditional sliding mode control is relied upon to overcome unknown disturbances, it can easily lead to large guidance command peaks, high energy consumption, and significant command chattering.
[0005] Therefore, it is necessary to propose a method that can estimate unknown maneuvers and model uncertainties online and compensate them into the angle-of-attack constraint guidance law, so as to improve the accuracy of angle-of-attack control and improve the quality of missile normal acceleration command while ensuring target interception. Summary of the Invention
[0006] The purpose of this invention is to provide a maneuvering target attack angle constraint guidance method based on a high-order sliding mode extended state observer, in order to solve the problems of insufficient attack angle control accuracy, weak disturbance compensation capability, and large peak value and fluctuation of traditional sliding mode guidance commands during the interception of unknown maneuvering targets.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: a maneuvering target attack angle constraint guidance method based on a high-order sliding mode extended state observer, the specific steps of which are as follows:
[0008] Step 1: Establish a relative motion model between the missile and the target in a two-dimensional plane. Assume that both the missile and the target can be considered as point masses, the missile's velocity is approximately constant during the terminal guidance phase, the missile's normal acceleration is the control input, and the target's normal maneuvering acceleration is unknown but bounded.
[0009] Step two: Determine the desired terminal line-of-sight angle based on the preset attack angle. When the missile's leading angle approaches zero at the terminal phase, the missile's trajectory angle and line-of-sight angle satisfy geometric constraints. Therefore, the attack angle constraint is transformed into a line-of-sight angle constraint, and the attack angle error is defined.
[0010] Step 3: Combine the target unknown maneuver term, modeling error term, and external disturbance term in the second-order dynamics of the line-of-sight angle into a total disturbance, and construct a state-space model with the attack angle error, the rate of change of the attack angle error, and the total disturbance as the extended states.
[0011] Step four involves designing a high-order sliding mode expansion state observer to estimate the rate of change of the attack angle error and the total disturbance in real time. The observer employs positive gain and replaces the sign function with a saturation function that has a boundary layer thickness to balance robustness and chattering suppression.
[0012] Step 5: Construct a sliding surface consisting of the attack angle error and the line-of-sight angular rate, and set the sliding surface parameters so that the attack angle error dynamically converges according to a predetermined path after the system reaches the sliding surface.
[0013] Step six: Construct missile normal acceleration commands based on the output of the high-order sliding mode extended state observer. These commands include compensation for known nonlinear relative motion terms, total disturbance estimation compensation, attack angle error convergence terms, and robust approach terms, and are made feasible through saturation functions and acceleration limiting.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0015] First, this invention unifies target maneuvering, model uncertainty, and external disturbances into a total disturbance, and estimates it in real time through a high-order sliding mode extended state observer, which can improve the anti-disturbance capability in unknown maneuvering target scenarios.
[0016] Second, this invention transforms the attack angle constraint into the desired terminal line-of-sight angle constraint, and designs a sliding surface in conjunction with the line-of-sight angular rate, so that the missile can simultaneously meet the interception accuracy and terminal attack angle requirements when hitting the target.
[0017] Third, the present invention uses the total disturbance estimate for compensation, which can reduce the dependence of traditional sliding mode guidance on large switching gain, thereby reducing peak acceleration, control energy and total command variation.
[0018] Fourth, this invention suppresses chattering and satisfies missile actuator constraints by using saturation functions and acceleration limiting, thus exhibiting good engineering application adaptability. Attached Figure Description
[0019] Figure 1 This is a flowchart illustrating the computational design process in an embodiment of the present invention.
[0020] Figure 2 This is a ballistic simulation diagram of a missile intercepting a serpentine maneuvering target in an embodiment of the present invention.
[0021] Figure 3 This is a schematic diagram of the convergence curves of attack angle error and line-of-sight angular rate in an embodiment of the present invention.
[0022] Figure 4 This is a schematic diagram of the missile normal acceleration command curve in an embodiment of the present invention. Detailed Implementation
[0023] The present invention will be further described below with reference to embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can make equivalent adjustments to the model parameters, observer parameters, and controller parameters.
[0024] This embodiment considers the terminal guidance problem of missile intercepting maneuvering targets in a two-dimensional plane.
[0025] Let the speed of the missile be... The target speed is The missile's normal acceleration command is The target's normal acceleration is The target's maneuverability is unknown and bounded, and the missile's velocity is approximately constant during the terminal guidance phase. We can ignore the effects of gravity, aerodynamic hysteresis, and the dynamic effects of the actuators.
[0026] S1: Establish a model of the relative motion between the projectile and the target.
[0027] Establish the relative motion geometry. Let the relative distance between the missile and the target be denoted as . The viewing angle is The missile's velocity angle is The target velocity angle is Define the missile lead angle. and target front angle They are respectively:
[0028] (1)
[0029] The equation of relative motion between the projectile and the target in the two-dimensional plane can then be written as:
[0030] (2)
[0031] In the formula, The relative distance between the missile and the target over time rate of change, The angle of view over time rate of change, For the missile velocity tilt angle with time rate of change, The target velocity tilt angle with time The rate of change.
[0032] S2: Attack Angle Constraint. The desired terminal line-of-sight angle is determined by the geometric relationship between the desired attack angle and the terminal missile lead angle approaching zero; if the desired attack angle is... Then the attack angle constraint can be expressed as the missile terminal trajectory angle satisfying ,when At that time, among them This represents the terminal hit time.
[0033] because When hitting the target at the end, it is usually required that the leading angle is close to zero, i.e. ,when Therefore, the attack angle constraint can be transformed into a line-of-sight angle constraint. ,when At that time, among them .
[0034] Define the attack angle error as The guidance target can be described as the design missile's normal acceleration. , making
[0035] (3)
[0036] This means that the missile enters the target at the desired angle of attack at the same time as it hits the target.
[0037] S3: Combine the target unknown maneuver term, modeling error term, and external disturbance term in the second-order dynamics of the line-of-sight angle into a total disturbance, and construct an extended state model with the attack angle error, the rate of change of the attack angle error, and the total disturbance.
[0038] S3.1: Second-order dynamics of the line-of-sight angle: for the line-of-sight angular rate Taking the derivative, we can obtain
[0039] (4)
[0040] target maneuver item and model uncertainty terms Treating it as a total disturbance, denoted as Then the line-of-sight angle dynamics can be simplified as follows:
[0041] (5)
[0042] S3.2: State-space model used in ESO design: To facilitate the design of high-order sliding mode extended state observers, the extended state model includes a first state, a second state, and a third state. The first state is the attack angle error. The second state is the attack angle error over time. rate of change The third state is the total disturbance. ,Right now
[0043] (6)
[0044] Differentiating it gives us the time-varying properties. rate of change:
[0045] (7)
[0046] In the formula, This is used to characterize the coupling effect between relative distance change and line-of-sight angle motion; Used to characterize the missile's normal acceleration acceleration of line of sight angle The efficiency of the control effect Relative distance over time Rate of change. Indicates the disturbance over time The rate of change; if we assume that the target maneuver and its rate of change are bounded, then we have ,in, Total disturbance The upper limit of the amplitude throughout the entire guidance range, The rate of change of total disturbance The upper limit of the amplitude over the entire guidance range.
[0047] S4: Design a high-order sliding mode extended state observer to estimate the rate of change of attack angle error and total disturbance in real time. The observer uses positive gain and replaces the sign function with a saturation function with boundary layer thickness to balance robustness and chattering suppression.
[0048] To achieve rapid estimation of the system state and total disturbance, a high-order sliding mode extended state observer is designed, including measures for attack angle error. Rate of change of attack angle error Total disturbance The three estimation channels are given by the following formula:
[0049] (8)
[0050] In the formula, Indicates the attack angle error estimate. Compared with actual value The deviation between them , , They are respectively , , The estimated value, i.e. . , , This represents the observer gain, and all values are positive. (Sign function) Used to enhance the robustness of the observer to unknown disturbances.
[0051] To reduce chattering in practical engineering applications, the sign function will be... Replace with saturation function :
[0052] (9)
[0053] In the formula, Let the boundary layer thickness be . The observer can then be rewritten as
[0054] (10)
[0055] This sliding mode ESO can utilize measurable attack angle error. At the same time, estimate its rate of change. Total disturbance Compared with traditional linear ESO, higher-order sliding mode ESO is more robust to perturbation changes and can obtain higher-accuracy perturbation estimation results in a finite time.
[0056] S4: Construct a sliding surface consisting of the attack angle error and the line-of-sight angular rate, and set the sliding surface parameters so that the attack angle error converges dynamically according to a predetermined method after the system reaches the sliding surface.
[0057] The total disturbance estimate can be obtained from the higher-order sliding mode ESO, i.e. .
[0058] To ensure that both the attack angle error and the line-of-sight angular rate converge simultaneously, a sliding mold surface is designed as follows:
[0059] (11)
[0060] In the formula, These are the parameters to be designed. When the system state reaches the sliding surface... After that, there was
[0061] (12)
[0062] Therefore, attack angle error The line-of-sight angular velocity will asymptotically converge to zero. It also converges to zero.
[0063] Differentiating with respect to the sliding surface, we have .
[0064] Substituting the attack angle error dynamics into the equation, we obtain:
[0065] (13)
[0066] To ensure the convergence of sliding mode variables, the convergence law is designed as follows:
[0067] (14)
[0068] In the formula, , This is the gain of the guidance law.
[0069] S6: Construct missile normal acceleration command based on the output of the high-order sliding mode expansion state observer.
[0070] Considering the total disturbance Unknown, estimated using ESO To compensate for this, the missile's normal acceleration command can be designed as follows:
[0071] (15)
[0072] The substitution yields:
[0073] (16)
[0074] In the formula, it is required that That is, the missile's lead angle is not close to To avoid chattering caused by the sign function, it can be... Replace with a saturation function:
[0075] (17)
[0076] In the formula, Let be the boundary layer thickness. The guidance law can then be written as:
[0077] (18)
[0078] The guidance law consists of four parts, the first of which... Used to compensate for known nonlinear relative motion terms; second term Used to compensate for unknown target maneuvers and total system disturbance; the third item Used to ensure that the attack angle error dynamically meets the desired convergence form; Fourth item Used to enhance sliding mode convergence and robustness.
[0079] Example
[0080] The initial states of the missile and the target are set to... , The missile and target speeds are respectively , The initial track angles are respectively , The expected terminal attack angle is set to To test the robustness of the guidance system to the maneuvering of an unknown time-varying target, the target employs continuous serpentine maneuvers with a normal acceleration of... ,in Therefore, the target normal acceleration is in The range changes continuously, and the maximum usable normal acceleration of the missile is set to... The simulation step size is... When the distance between the target and the projectile is less than The missile's hit on the target is determined in real time. The proposed guidance law uses a linear sliding mode surface. ,in The parameter is set to , , The high-order sliding mode ESO parameters are: To reduce chattering caused by sliding mode switching, the boundary layer width is set to... . Figure 1 This is a flowchart illustrating the calculation design process in an embodiment of the present invention. Figure 2 This is a ballistic simulation diagram of a missile intercepting a serpentine maneuvering target in an embodiment of the present invention. Figure 3 This is a schematic diagram of the convergence curves of attack angle error and line-of-sight angular rate in an embodiment of the present invention. Figure 4 This is a schematic diagram of the missile's normal acceleration command curve in an embodiment of the present invention. Simulation results show that the present invention can achieve precise interception, maintain a small terminal attack angle error, and the peak normal acceleration does not exceed the set limit.
Claims
1. A maneuvering target attack angle constraint guidance method based on a high-order sliding mode extended state observer, characterized in that, Includes the following steps: Establish a relative motion model between the missile and the maneuvering target in a two-dimensional plane; Determine the desired end-point line-of-sight angle based on the desired attack angle, and construct the attack angle error; The unknown maneuver of the target, the uncertainty of the model, and the external disturbances are combined into a total disturbance to establish an extended state model; Design a high-order sliding mode expansion state observer to estimate the rate of change of attack angle error and the total disturbance in real time; Construct a sliding surface based on attack angle error and line-of-sight angular rate; The missile's normal acceleration command is generated based on the sliding surface, the output of the higher-order sliding mode expansion state observer, and the saturation function, so that the missile meets the preset attack angle constraint when it hits the maneuvering target.
2. The method according to claim 1, characterized in that, The relative motion model uses the relative distance between the projectile and the target. viewing angle Missile speed tilt angle and the angle of inclination of the target velocity As a state description quantity, and in terms of missile normal acceleration As the control variable to be designed, the target normal maneuvering acceleration As an unknown bounded input.
3. The method according to claim 1, characterized in that, Desired end-view angle From the expected angle of attack and terminal missile lead angle The geometric relationship approaching zero is determined, and the attack angle error is defined. Actual viewing angle With the desired end line of sight angle The deviation between them, i.e. .
4. The method according to claim 1, characterized in that, The extended state model includes a first state, a second state, and a third state, with the first state representing the attack angle error. The second state is the attack angle error over time. rate of change The third state is the total disturbance. The total disturbance Including the unknown target maneuver term, the relative motion model uncertainty term, and the external disturbance term, the extended state model of the system is obtained as follows: ； In the formula, For the angle of attack error, This is the actual viewing angle. The desired end-view angle; Differentiating it gives its time rate of change: ； In the formula, This is used to characterize the coupling effect between relative distance change and line-of-sight angle motion; Used to characterize the missile's normal acceleration acceleration of line of sight angle The efficiency of the control effect The relative distance between the missile and the target. Relative distance over time Rate of change; For the missile's forward angle, Indicates the disturbance over time The rate of change; if we assume that the target maneuver and its rate of change are bounded, then we have ,in, Total disturbance The upper limit of the amplitude throughout the entire guidance range, The rate of change of total disturbance The upper limit of the amplitude over the entire guidance range.
5. The method according to claim 1, characterized in that, The high-order sliding mode expansion state observer includes the attack angle error. Rate of change of attack angle error Total disturbance The three estimation channels are designed with positive observer gain to ensure that the observation error converges under the condition that the rate of change of the disturbance is bounded. ； In the formula, This indicates the deviation between the estimated and actual attack angle error values. , , They are respectively , , The estimated value, i.e. ; , , The observer gain is represented by a positive sign function. Used to enhance the robustness of the observer to unknown disturbances. The relative distance between the missile and the target. Relative distance over time Rate of change; For the missile's forward angle, This is the actual viewing angle. The actual line-of-sight angle over time rate of change, This refers to the missile's normal acceleration.
6. The method according to claim 5, characterized in that, To reduce chattering in practical engineering applications, the sign function is replaced with a saturation function. ,get: ； In the formula, , This represents the boundary layer thickness.
7. The method according to claim 1, characterized in that, Sliding surface It is obtained by linear combination of attack angle error and line-of-sight angular rate, and the attack angle error is asymptotically converged after the missile reaches the sliding surface by setting positive sliding surface parameters.
8. The method according to claim 1, characterized in that, missile normal acceleration The instructions include: a first term for compensating for known nonlinear relative motion terms; a second term for compensating for the total disturbance estimate; a third term for ensuring the attack angle error satisfies a predetermined convergence dynamic; and a fourth term for enhancing closed-loop robustness, the specific formula of which is as follows: ； In the formula, For the missile's normal acceleration, The relative distance between the missile and the target. For the missile's forward angle, This is the actual viewing angle. The actual line-of-sight angle over time rate of change, They are respectively The estimated value, The rate of change of the attack angle error. For sliding surface, , For guidance law gain, These are the sliding mode parameters.
9. The method according to claim 8, characterized in that, To avoid chattering caused by the sign function, Replace with saturation function ,get: ； In the formula, This represents the boundary layer thickness.
10. The method according to any one of claims 1 to 10, characterized in that, The method is used for two-dimensional terminal guidance to intercept serpentine maneuvering targets or other unknown bounded maneuvering targets, so that when the relative distance between the missile and the target meets the hit conditions, the attack angle error and line-of-sight angular rate both approach zero.