Integrated Guidance And Control Research Articles

Partial state-constrained integrated guidance and control for an STT missile with self-adjusting prescribed performance via non-barrier Lyapunov function method

A state-constrained guidance and control law is vital to the flight safety of an aerial interceptor against a maneuvering target. Taking the flight angle limitations, manipulation saturation, and terminal constraints into consideration, a novel integrated guidance and control (IGC) schema with a self-adjusting prescribed performance is proposed. To avoid the feasibility condition via the conventional barrier Lyapunov function-based method, a new state-dependent nonlinear mapping function is designed, based on which the state-constrained IGC system is converted into a constrained-free model. A novel prescribed performance with a self-tuning mechanism is proposed to guarantee satisfied transit and steady guidance performances. The backstepping technique combined with super-twisting integral sliding modes and newly defined predefined-time disturbance observers is implemented to generate state-constrained virtual command signals. All the signals in the closed-loop system are strictly proven to be bounded by Lyapunov stability theory. The simulation results show the effectiveness of the proposed IGC schema.

Adaptive robust integrated guidance and control for thrust-vector-controlled aircraft by solving LQR online

In order to enhance the matching relationship between guidance subsystem and control subsystem of the thrust-vector-controlled aircraft, a kind of sufficient modeling and adaptive robust design facing to integrated guidance and control (IGC) is proposed. With respect to the researched aircraft, a linear state-dependent mathematical model facing to IGC design is first established. Based on the as-built model, a new kind of adaptive robust IGC law is proposed and it is composed by an adaptive optimal IGC law and a robustness-improved IGC law. In order to guarantee the global stability of time-varying control system, the adaptive optimal IGC law is designed by solving Riccati matrix equation on line and using matrix Sign function method. Furthermore, in order to enhance the robust ability against the unmatched system uncertainties, the robustness-improved IGC law is designed by using dynamic surface control approach and extended state observing strategy. Simulation results present that, the proposed IGC scheme presents more performance advantages compared with traditional IGC schemes, including the improvement of guidance precision and attitude stabilization. Furthermore, in the conditions of 256 simulation combinations, the minimum relative distances between aircraft position and target position are distributed from 0.103m to 5.333m, and the average value is 2.208m, which means the proposed IGC scheme possesses strong robustness against different and time-varying model uncertainties.

Integral barrier Lyapunov function-based fixed-time integrated guidance and control with asymmetric field-of-view angle constraints

The missile integrated guidance and control (IGC) problem with seeker’s asymmetric field-of-view (FOV) angle constraints is addressed. In the introduced model, the fin deflections controller is used to drive the body line-of-sight angle rate, which avoids the solving and tracking of aerodynamic angles in traditional IGC method. A novel fixed-time convergence virtual input based on the integral barrier Lyapunov function is designed to ensure the asymmetric FOV angle constraints are never violated. The virtual input is tracked by a new proposed pre-defined fixed time controller with adjustable initial convergence speed. The lumped uncertainty including aerodynamic coefficient and target maneuvering is coped by the fixed-time disturbance observer. It is proved that the closed-loop system states are converged to the bounded region in a fixed-time and the asymmetric FOV angle constraints are satisfied. The 6-degree of freedom flight simulations and comparisons verified the advantages of the proposed algorithm.

Prescribed-time integrated guidance and control for bank to turn reentry vehicle

In this paper, a novel prescribed-time integrated guidance and control (IGC) with spiral maneuvering deceleration (SMD) method is developed for bank to turn (BTT) reentry vehicle with the consideration of elevation angle and terminal velocity constraints. First, a strict feedback form IGC model is established for BTT reentry vehicle under multiple constraints. Second, a prescribed-time sliding mode controller (SMC) based on prescribed-time extended state observer (ESO) is designed to hit the ground fixed target with the desired line of sight (LOS) elevation angle. Then in order to make the reentry vehicle achieve a better strike effect, it is necessary to constrain the terminal velocity of the reentry flight, a SMD scheme is proposed to achieve the desired terminal velocity. Finally, the efficiency of the proposed scheme is verified by six–degree–of–freedom (6DoF) numerical simulations.

Multiple‐missile fixed‐time integrated guidance and control design with multi‐stage interconnected observers under impact angle and input saturation constraints

AbstractIn this paper, a novel three‐dimensional fixed‐time integrated guidance and control (IGC) scheme with multi‐stage interconnected observers is proposed for cooperative attacks using multiple missiles against a maneuvering target under impact angle and input saturation constraints. External disturbances, modeling errors, and aerodynamic parameter variations are considered as system uncertainties and a three‐channel fully coupled IGC model for multiple missiles is established. The IGC system is designed optimally based on fixed‐time stability theory, sliding mode control, and the backstepping technique. Three inter‐cascaded fixed‐time disturbance observers based on an improved super‐twisting algorithm are designed to estimate and compensate for system uncertainties. Second‐order command filters are used to constrain virtual control signals, and additional filtering error subsystems are introduced to compensate for the tracking errors of filters. System stability and uniformly ultimately fixed‐time boundedness of all states are proven using the Lyapunov stability theory. Finally, the limits of the acceleration components of the maneuvering target perpendicular to the line of sight direction are derived. The effectiveness of the designed IGC scheme and the ability of multi‐stage interconnected observers to sense disturbances with each other are verified through simulations.

Integrated guidance and control design by active disturbance rejection method for high-velocity target interceptor with DCS thruster

The present paper proposes a novel integrated guidance and control (IGC) method for engaging with high-speed targets such as ballistic projectiles. considering an extreme short period of terminal engagement due to high relative velocity between target and interceptor, it is particularly important for IGC law to show desirable performance in the presence of various uncertainties (e.g. variation in aerodynamic coefficients) and disturbances (e.g. target maneuver and drag). This article extends the ICG law for mismatched and feedback form equations based on the Active Disturbance Rejection Control (ADRC) method using the back-stepping technique and the Reduced-order Extended State Observer (RESO). The primary consideration is the application of thrusters on the center of mass as the Divert Control System (DCS), along with the daisy-chain technique for control allocation between the fins and thruster commands. Contrary to previous research, the filter and angle measurement error are modeled for the seeker as a crucial parameter to highlight the significance of the thruster. The simulation results indicate the efficiency of the developed method for near-miss or hit-to-kill engagement with tactical ballistic targets. It is shown that the thruster plays a significant role in high-altitude engagements, specifically in the presence of non-ideal seeker. Finally, using the Monte Carlo simulation, it is proved that adding inner loops to the developed technique will not remove the IGC’s advantage over the conventional approach and Non-singular Terminal Sliding Mode (NTSM) guidance law.

Integrated guidance and control with impact angle and general field-of-view constraints

This paper investigates the problem of integrated guidance and control (IGC) law design with impact angle and general field-of-view (FOV) constraints. Firstly, the IGC model for intercepting non-maneuvering moving target is parameterized by state-dependent coefficient matrices. The nominal IGC law for intercepting the target with the desired impact angle is obtained by solving the state-dependent Riccati equation. Secondly, since the relative degrees of the general FOV constraints with respect to the IGC model exceed one, the high-order control barrier functions are constructed. The satisfaction of the FOV constraints is equivalent to ensuring that the superlevel sets defined by the barrier functions are forward invariant, which is converted into affine constraints on the control input. The nominal IGC law is modified in a minimally invasive way by quadratic programming. Then, the proposed method is extended to the case of intercepting maneuvering target by leveraging a relative coordinate frame. Finally, numerical simulations are conducted to verify the effectiveness of the proposed method.

Nonlinear transformed function-based adaptive finite-time integrated guidance and control design with full state constraints

This paper proposes a novel finite-time integrated guidance and control (IGC) design for skid-to-turn (STT) missiles, taking full state constraints into account. Firstly, the actuator saturation is converted into a state constraint. Secondly, to handle full state constraints effectively, the “non-constrained” IGC (NCIGC) model is constructed by combining the IGC model with a permissible set of states and applying a nonlinear transformed function. Thirdly, a finite-time full state constraints IGC scheme based on the NCIGC model is presented. According to Lyapunov stability theory, the proposed IGC method is verified to ensure that all states of the IGC model converge to a small neighborhood near zero within a finite time while satisfying the predefined state constraints. Finally, numerical simulations are performed to demonstrate the effectiveness and robustness of the proposed IGC scheme.

Integrated guidance and control for underactuated fixed-trim moving mass flight vehicles

This work presents a novel real integrated guidance and control (IGC) scheme that solves the issues of underactuation, fixed-trim angle-of-attack and three-dimensional motion together for moving mass flight vehicles (MMFVs). Firstly, an underactuated IGC model containing the information of flight vehicle dynamics and three-dimensional relative motion is formulated, and the command error angle is designed to improve the capability of maneuvering penetration. Secondly, the modeled disturbances and uncertainties are regarded as the lumped disturbances, the values and derivatives of which are estimated by four second-order disturbance observers (DOs). Thirdly, different from the traditional backstepping-based partial IGC scheme, a novel sliding mode based real IGC law is designed, which generates the command moving mass offset input by only a single controller, thereby essentially eliminating the cross time-scale problem between the guidance and control loops. Moreover, this IGC law simultaneously achieves the command error angle tracking and the side-slip-angle stabilization with only a control input. Finally, the Lyapunov function is used to illustrate the asymptotic stability of the entire system, and numerical simulations with multiple disturbances, varied flying circumstances, and a comparison with other control strategies are carried out to show the effectiveness and superiority of the proposed IGC strategy.

Three-dimensional approximate cooperative integrated guidance and control with fixed-impact time and azimuth constraints

A novel three-dimensional (3D) approximate cooperative integrated guidance and control (ACIGC) scheme based on backstepping control (BC), sliding mode control (SMC), dynamic surface control (DSC), and a 3D reduced-order extended state observer (ESO) for multiple hypersonic skid-to-turn (STT) missiles simultaneously attacking ground-maneuver targets is proposed in this study, which considers a fixed-impact azimuth and time constraints. First, we established a novel integrated guidance and control (IGC) model that includes the missile-target relative distance and azimuth based on the missile-target engagement dynamics, attitude dynamics, and first-order delay dynamics of the rudder. It is a 3D fifth-order strict-feedback time-varying nonlinear model with mismatched uncertainties. Second, a 3D ACIGC scheme was designed, where a cooperative strategy was designed by transforming a fixed-impact time constraint into a nominal range-to-go constraint. The IGC model consists of seeker, guidance, angle-of-attack, attitude, and rudder subsystems based on the BC, and the SMC designs each subsystem. The DSC obtains the derivatives of virtual control commands, which solves the “differential explosion” caused by the BC. The unknown target acceleration, unmodeled parts of the system states, perturbations caused by time-varying parameters, and external disturbances are regarded as lumped disturbances, which are estimated and compensated for by the 3D reduced-order ESO to improve the robustness. Subsequently, the closed-loop system was proven to be stable, and the system states were ultimately uniformly bounded using Lyapunov theory. Finally, the simulation results of three missiles attacking a simultaneously ground-maneuvering target and Monte Carlo simulations demonstrated the effectiveness and robustness of the proposed ACIGC scheme.

Asymmetric BLOS constraint-involved intelligent integrated guidance and control approach for flight vehicle equipped with strapdown seeker

The paper investigates the integrated guidance and control (IGC) issue for flight vehicle equipped with strapdown seeker. Distinguished from the routine flight vehicle in literatures, the equipped strapdown seeker is fixedly connected with the vehicle body and thus asymmetric body line of sight (BLOS) constraint is imposed, which makes the IGC design more challenging. Focusing on the point, an intelligent integrated guidance and control approach is proposed by virtue of two specific mechanisms. The improved explicit reference governor technique is adopted to generate auxiliary reference command to ensure asymmetric BLOS limitation not to be violated. On the other hand, the reinforcement learning-based adaptive dynamic programming algorithm is further integrated to guarantee the fine tracking of the auxiliary reference command. Consequently, the satisfactory miss distance is achieved despite of the asymmetric BLOS constraint and unmatched uncertainties, and the stability of the closed-loop system is analyzed. The numerical simulation results demonstrate the effectiveness of the proposed method.

Three-dimensional low-order fixed-time integrated guidance and control for STT missile with strap-down seeker

Strap-down seeker is rigidly fixed onto the missile body, which results in detection information being coupled to the missile’s attitude and having a narrow field-of-view (FOV). During the terminal guidance flight, attitude adjustment of the missile may lose the target’s lock and reduce interception accuracy. Therefore, this paper investigates three-dimensional integrated guidance and control (IGC) under the constraints of the FOV and roll angle for skid-to-turn (STT) missile with strap-down seeker. A new low-order IGC model is constructed by establishing a second-order model of body line-of-sight (BLOS) angle based on strap-down decoupling theory and combining it with the second-order roll angle equation. Furthermore, a low-order fixed-time IGC scheme is developed using the integral barrier Lyapunov function (iBLF) to limit BLOS and roll angles. Fixed-time filter, which avoids the “complexity explosion” caused by conventional back-stepping technique, is utilized for obtaining virtual control command and its derivative. A fixed-time disturbance observer is introduced to compensate for the lumped disturbance. According to Lyapunov stability theory, it is proven that the proposed IGC scheme can make the closed-loop system converge within a fixed time. Finally, the effectiveness and robustness of the IGC scheme are verified by various numerical simulations.

Piecewise Trajectory and Angle Constraint Based Fractional-order Sliding Mode Control

This paper proposes an approach for piecewise trajectory planning and fractional-order sliding-mode guidance of a two-stage launched miniature munition with the laser beam riding steered guidance technology. In the proposed approach, firstly, the polynomial description is used as an expected trajec- tory. Then consider the random external disturbances/parametric uncertainties and other factors deteriorate the tracking control performances of the miniature munition. To reduce the chatter- ing caused by modeling errors and external disturbances and achieve fast speed and high accuracy tracking performances for miniature munition, based on adaptive multi-power reaching strategy, an integrated guidance and control (IGC) method with the fractional-order sliding-mode guidance law (FOSMGL) is introduced. The designed fractional-order sliding surfaces ultimately and successively allow both the trajectory and the attitude angle converge to expected value in a finite time. In addition, considering the case of a moving target, a feedfor- ward compensation mechanism, which decreases the lag of the guidance system, is imposed using an additional compensated term obtained from the attitude angle error. The convergence and reachability of the proposed algorithm in finite-time are analyzed using the Lyapunov function method. The validity and practicability of the proposed method are verified by a numerical example.

Constrained Integrated Guidance and Control Scheme for Strap-Down Hypersonic Flight Vehicles with Partial Measurement and Unmatched Uncertainties

This paper investigates the issue of integrated guidance and control (IGC) design for strap-down hypersonic flight vehicles with partial measurement information and unmatched uncertainties. A constrained IGC scheme is proposed by combining the barrier Lyapunov function-based backstepping methodology and the specific output-based finite-time disturbance observer. Different from the existing methods, which require the state information and matched disturbances, the main features of the presented approach is capable of addressing the partial measurement knowledge and unmatched uncertainties simultaneously. The IGC model of hypersonic flight vehicles is first formulated, and based on that, the specific output-based finite-time disturbance observer (OFTDO) is proposed to achieve the finite-time estimation of the unmatched uncertainties through the output. Then, the constrained IGC strategy is constructed via the backstepping technique. The stability of the closed-loop system including the estimation and tracking errors dynamics is analyzed in detail. The effectiveness of the proposed method is verified by numerical simulations and Monte-Carlo tests.

Adaptive NN control of integrated guidance and control systems based on disturbance observer

This paper investigates the nonlinear integrated missile guidance and control system with uncertainties and external disturbances, and a novel adaptive neural network (NN) control scheme is proposed with the help of the estimations obtained by NN and disturbance observer (DOB). NN weight learning law and DOB are updated in accordance with the tracking and estimation errors. Under the action of proposed adaptive NN laws, a good tracking property and guidance effects can be achieved for the missile integrated guidance and control (IGC) system. Furthermore, the IGC system is certified to be stable by employing the Lyapunov function. Finally, simulation results of two different scenarios account for the correctness of the designed schemes. It is worth mentioning that the missile intercepting process shows a smoother trajectory and smaller miss distance could be accomplished by the proposed adaptive NN control approach.

Neural learning control of missile interception against dynamics uncertainty and target evasive maneuver

AbstractThe integrated guidance and control (IGC) design for the advanced interceptors against targets in progress of implementing evasive maneuvers is investigated. During interception, the target's unknown maneuver accelerations, and the extra angle of attack (AOA) caused by wind effects, are considered as disturbances. For the sake of enough hit‐to‐kill accuracy under multisource disturbances, the neural networks (NNs) and disturbance observer (DOB) are applied to solve the model inaccuracy and external disturbance. As a result, a novel DOB‐based neural controller can accomplish high tracking accuracy and hit‐to‐kill interception performance can be accomplished. Simulations studies demonstrate the validity and advantage bring by the DOB‐based neural control.

Field-to-View Constrained Integrated Guidance and Control for Hypersonic Homing Missiles Intercepting Supersonic Maneuvering Targets

An integrated guidance and control (IGC) scheme considering the field-of-view (FOV) constraint is proposed in this paper for hypersonic skid-to-turn (STT) missiles with a strapdown seeker intercepting a high-speed maneuvering target, which is based on the backstepping control (BC), barrier Lyapunov function (BLF), sliding mode control (SMC), dynamic surface control (DSC), and reduced-order extended state observer (ESO). First, a fifth-order strict feedback IGC model considering the rudder delay dynamics is derived, which also considers the drag effect on the axial velocity. Second, the missile guidance control system based on the BC consists of seeker, guidance, angle-of-attack, attitude, and rudder subsystems. The seeker subsystem was designed based on the BLF, and the other four subsystems were designed based on the SMC. The system-lumped disturbances, including unknown target maneuvers, unmodeled parts, perturbations caused by aerodynamic parameter variations, and external disturbances, were estimated and compensated for using the reduced-order ESO. The DSC prevented the “differential explosion” caused by virtual control commands introduced by the BC. Subsequently, the stability of the closed-loop system was strictly proven using the Lyapunov theory, and the boundedness of the FOV angle was strictly derived. Finally, the simulation results demonstrated the effectiveness and robustness of the proposed IGC scheme.

A New Sliding Mode Control Algorithm of IGC System for Intercepting Great Maneuvering Target Based on EDO.

To intercept the great maneuvering target, combining with the sliding mode and the extended disturbance observer, a new control algorithm for integrated guidance and control (IGC) system is proposed in this paper. Firstly, the paper formulates the Missile–Target problem. Then the paper establishes an uncertain IGC dynamic model where the nonlinearities, the perturbations and the maneuvering of the target are regarded as disturbance. Secondly, a second-order disturbance observer is designed to estimate the disturbance and their derivatives.. After this, combining with the second-order disturbance observer, a modified sliding surface and the corresponding reaching law are designed to obtain the rudder deflection command directly. Thus, the real sense of IGC system is achieved. Next, the paper uses the Lyapunov stability theory to prove the stability of the system. Finally, the paper provides different simulation cases, which have different maneuver modes of the target, to demonstrate the superiority of the proposed method in reducing the response time, increasing the rudder response, and having a high interception probability.

Impact angle constrained fuzzy adaptive fault tolerant IGC method for Ski-to-Turn missiles with unsteady aerodynamics and multiple disturbances

An impact angle constrained fuzzy adaptive fault tolerant integrated guidance and control method for Ski-to-Turn (STT) missiles subject to unsteady aerodynamics and multiple disturbances is proposed. Unsteady aerodynamics appears when flight vehicles are in a transonic state or confronted with unstable airflow. Meanwhile, actuator failures and multisource model uncertainties are introduced. However, the boundaries of these multisource uncertainties are assumed unknown. The target is assumed to execute high maneuver movement which is unknown to the missile. Furthermore, impact angle constraint puts forward higher requirements for the interception accuracy of the integrated guidance and control (IGC) method. The impact angle constraint and the precise interception are established as the object of the IGC method. Then, the boundaries of the lumped disturbances are estimated, and several fuzzy logic systems are introduced to compensate the unknown nonlinearities and uncertainties. Next, a series of adaptive laws are developed so that the undesirable effects arising from unsteady aerodynamics, actuator failures and unknown uncertainties could be suppressed. Consequently, an impact angle constrained fuzzy adaptive fault tolerant IGC method with three loops is constructed and a perfect hit-to-kill interception with specified impact angle can be implemented. Eventually, the numerical simulations are conducted to verify the effectiveness and superiority of the proposed method.

Reference-trajectory-planner–based integrated guidance and control under input saturation and impact angle constraint

This paper investigates the integrated guidance and control (IGC) problem for intercepting maneuvering targets subject to the impact angle and input saturation. In order to elegantly implement tracking control under constraints, the whole controller includes the reference trajectory planner for generating reference trajectory, and the reference trajectory tracking controller for tracking the generated reference trajectory. The trajectory tracking controller is based on the command filter backstepping design under the time-domain separation, and the reference trajectory planner with a kind of reference model governor takes into account the available regulation ability of the trajectory tracking controller, so as to improve the adaptability of the proposed control scheme. The two cooperate with each other to improve the stability of guidance interception system and come out a more reasonable interception path. The simulation comparison results are provided to illustrate the superiority of the reference-trajectory-planner–based IGC law.