Integrated Guidance And Control Scheme Research Articles

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.

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 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.

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.

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.

Three-dimensional integrated guidance and control with input saturation and impact angle constraints

Considering the problem of a skid-to-turn (STT) interceptor attacking maneuvering targets in the three-dimensional space, a new integrated guidance and control (IGC) law with the constraints of impact angles and input saturation is developed. To achieve the finite-time convergence and satisfactory input characteristics, a time-varying sliding mode control (TVSMC) method is presented based on a time base generator function. To this end, the IGC scheme is developed based on the TVSMC and the back-stepping. At each step, the derivative of the virtual signal is approximated by a tracking differentiator. Meanwhile, an auxiliary compensation system is designed to reduce the adverse effect raised from the saturation error. Moreover, the modeling uncertainties and disturbances are attenuated effectively by using fractional power extended state observers to estimate them. The closed-loop system states are proved to be uniformly ultimately bounded and the controlled states are proved to converge into small neighborhoods of the origin at the interception time. Finally, the performance of the presented IGC law is verified through numerical simulations.

Impact angle-constrained integrated guidance and control for supersonic skid-to-turn missiles using backstepping with global fast terminal sliding mode control

An integrated guidance and control (IGC) scheme based on global terminal sliding mode control (GTSMC), backstepping control (BC), linear feedback (LF), dynamic surface control (DSC), reduced-order extended state observer (ESO) for a supersonic skid-to-turn (STT) interceptor intercepting maneuvering targets is presented. The IGC scheme considers the delay dynamics of the rudder and solves the impact angle constraint. First, a fifth-order strict-feedback nonlinear IGC model with mismatched uncertainties was established taking into account the rudder delay dynamics. Second, the guidance and control system based on BC consists of the guidance subsystem, normal overload subsystem, attitude subsystem, rudder subsystem. Each subsystem was designed based on the GTSMC and LF. In particular, the GTSMC was designed for the guidance subsystem to ensure the fast convergence of the line-of-sight angle. The DSC was introduced to calculate virtual commands to prevent “differential explosion”. The unknown lumped disturbances, including target maneuvers, external disturbances, and perturbations caused by the aerodynamic parameters, were accurately estimated and compensated for by the reduced-order ESO in the proposed IGC scheme. The closed-loop system was proved to be stable and the system states to be uniformly bounded using Lyapunov theory. Finally, simulation results demonstrated the superiority of the proposed IGC scheme compared to previously proposed schemes.

Three-dimensional low-order finite-time integrated guidance and control design with side-window constraint

The infrared seeker has usually been mounted to the side of the hypersonic vehicle's head to reduce the performance degradation caused by the severe aerodynamic heating. In this way, the rotational dynamics of the flight vehicle and the line-of-sight (LOS) need to satisfy a particular constraint so that the target can be located in the seeker's field-of-view (FOV) during the whole engagement. Consequently, the coupling between the centroid dynamic and the rotational dynamic is more significant. To deal with the side-window constraint and the aforementioned significant coupling, the novel vehicle-target relative motion model in the body-LOS coordinate system is introduced to describe the guidance problem accurately. Combined with the dynamics of body angular rates and the fact that the derivative of angular rates appears in the proposed relative motion model, a novel three-dimensional (3D) low-order integrated guidance and control (IGC) design model is obtained. Furthermore, the IGC design with a side-window constraint can be converted to an output constraint problem of a low-order nonlinear system. Meanwhile, the desired reference trajectories of the FOV angles are designed to meet the asymmetric FOV constraint and the terminal accuracy requirement, simultaneously. Based on the asymmetric barrier Lyapunov function (BLF), finite-time stability theory and the modified dynamic surface technique, a novel 3D low-order adaptive finite-time IGC scheme with side-window constraint is proposed in this paper. The finite-time stability of the closed-loop system is proven, and the side-window constraint would never be violated using Lyapunov theory. Finally, the effectiveness and robustness of the newly proposed IGC algorithm are demonstrated by means of numerical simulations.

Integral barrier Lyapunov function-based three-dimensional low-order integrated guidance and control design with seeker's field-of-view constraint

As the strap-down seeker with its detector is fixed onto the body of the flight vehicle, its measurement is coupled with the information of the attitude motion of the vehicle's body, which results that the inertial line-of-sight (LOS) angular rate used in the traditional guidance laws cannot be measured. Besides, the process that the vehicle adjusts its attitude to realize the instantaneous overload command may cause the target to be outside the field-of-view (FOV) of the seeker. To deal with the FOV constraint and the lack of the inertial LOS angular rate, the novel body-LOS coordinate system based relative motion equations are derived, in which the derivative of attitude angular rates appears. Combined with the dynamics of attitude angular rates, the original low-order integrated guidance and control (IGC) design model with FOV constraint and the roll channel IGC design model are established. Furthermore, an integral Barrier Lyapunov function (IBLF) based three-dimensional low-order IGC scheme with the FOV constraint is proposed in this paper. Meanwhile, the adaptive algorithms are employed to estimate the square of the upper bound of the disturbance, which would be compensated in the IGC scheme to improve the robustness of the control system. Both system order and tuning parameters of the proposed low-order IGC algorithm dramatically decrease, and the design procedure is significantly simplified. With the aid of Lyapunov stability analysis, states of the IGC closed-loop system are proved to be uniformly ultimate bounded. Finally, extensive numerical simulations are carried out to validate the effectiveness and robustness of the newly proposed IGC scheme.

A Novel IGC Scheme for RHV with the Capabilities of Online Aerodynamic Coefficient Estimation and Trajectory Generation

A novel integrated guidance and control (IGC) scheme for a Re-entry Hypersonic Vehicle (RHV) is proposed with the capabilities of online aerodynamic coefficient estimation based on an Unscented Kalman Filter and online trajectory generation based on the Gaussian pseudospectral method. A linear quadratic regulator is adopted for trajectory tracking guidance and a second-layer sliding mode controller is designed for attitude control. The variation of lift and drag coefficients are modeled and estimated online, based on which a new trajectory can be generated. The commands of trajectory generation are set as moments of actuators and their extremums pose more constraints on the rate and acceleration of flow angles. Comprehensive simulations are conducted and comparable IGC performances with normal conditions are obtained under large aerodynamic coefficient errors according to online generated trajectory, which proves the effectiveness and advantages of the proposed IGC scheme.

Multi-constraints adaptive finite-time integrated guidance and control design

The skid-to-turn hypersonic vehicle is subject to the complex aerodynamic uncertainty and random wind disturbance. Besides, actuator saturation and full state constraints, consisting of attack angle, sideslip angle, bank angle and body angular rates should be considered to guarantee structural safety and flight stability. However, these uncertainties and constraints will lead to a great challenge in the integrated guidance and control (IGC) design. To address this issue, a novel multi-constraints adaptive finite-time IGC scheme, based on barrier Lyapunov function (BLF), finite-time stability theory and back-stepping method, is proposed in this paper. While the piecewise saturation is employed to restrict the virtual commands of the constrained states, BLF is used to guarantee the compensated tracking errors bounded. Moreover, three novel auxiliary systems are constructed to eliminate the negative effect, suffered from possible saturation. Meanwhile, adaptive technique is adopted to estimate the unknown upper bound of disturbances. With the aid of Lyapunov stability analysis, the states can be proved to remain in the constrained set and converge into the small regions in a finite time. Numerical simulations are performed to demonstrate the effectiveness and robustness to the initial state deviations and aerodynamic parameter uncertainty of the proposed adaptive IGC scheme.

Finite-time integrated guidance and control system for hypersonic vehicles

A finite-time integrated guidance and control (IGC) method is proposed in this study for hypersonic vehicles. The IGC dynamic model is initially built by combining the 3D relative kinematics and dynamics equations. Then, by introducing the adaptive control technology and the backstepping approach, an IGC scheme with adaptive parameters is presented to guarantee the finite-time stability of a closed-loop control system on the basis of Lyapunov stability theory. Nonlinear simulation results demonstrate the effectiveness and robustness of the proposed IGC method for hypersonic vehicles compared with other robust IGC methods.

Three-dimensional integrated guidance and control for strap-down missiles considering seeker’s field-of-view angle constraint

This paper investigates a novel three-dimensional (3D) integrated guidance and control (IGC) method for skid-to-turn (STT) missiles with strap-down seeker. Firstly, a nonlinear IGC model considering seeker’s field-of-view (FOV) constraint is built by employing the strap-down decoupling model, based on which the strict feedback state equation with matched and unmatched uncertainties is derived. Secondly, to handle the FOV angle and the roll angle constraints, an IGC law is proposed by combining dynamic surface control (DSC) approach with integral barrier Lyapunov function (iBLF), by which an adaptive law is employed to estimate the square of the disturbance bound. Finally, the uniform ultimately boundedness of the closed-loop system is proved strictly based on the Lyapunov stability theory, and the effectiveness and robustness of the proposed IGC scheme are illustrated with numerical simulations.

A novel non-singular terminal sliding mode control-based integrated missile guidance and control with impact angle constraint

Abstract A novel impact angle constrained integrated guidance and control (IGC) scheme is proposed with non-singular terminal sliding mode control (NTSMC) technique for missile to intercept a maneuverable target. Firstly, an IGC design model is innovatively established in a strict feedback form which selects the normal overload as the system state in replace of the angle of attack so that the system states both are measurable. On this basis, an IGC law is proposed to guarantee the impact angle converge to the expected command within a finite time and to improve the robustness against the multiple disturbances which include the model parameter uncertainties and the target maneuvering by incorporating the NTSMC method and the extended state observer (ESO) technique. In order to avoid the chattering phenomenon, the smooth derivative of the intermediate control command which is obtained by the introduced nonlinear tracking differentiator (TD) is adopted into the control loop. Then, the stability of closed-loop integrated system is rigorously proved by utilizing the Lyapunov theorem. Finally, extensive contrast simulation results are presented to validate the efficiency, superiority and robustness of the suggested IGC scheme.

Integrated guidance and control with partial state constraints and actuator faults

In this paper, a novel adaptive integrated guidance and control (IGC) scheme is proposed for skid-to-turn (STT) missile with partial state constraints and actuator faults. Considering the strict-feedback form of the IGC model, the dynamic surface control (DSC) approach is adopted to design the IGC scheme. To prevent the attack angle, sideslip angle and velocity deflection angle from violating the constraints, the barrier Lyapunov function (BLF) and modified saturation function are employed in the IGC design procedure. Moreover, an auxiliary system is constructed to remove the adverse effects that caused by the modified saturation function. The adaptive laws are constructed to estimate the actuation effectiveness of actuators and the upper bounds of lumped uncertainties in the IGC model. It is theoretically shown that all signals in the closed-loop system are bounded while the state constraints are not violated in presence of actuator faults and uncertainties. Numerical simulation results are presented to verify the effectiveness and robustness of the proposed IGC scheme.

Barrier Lyapunov function-based integrated guidance and control with input saturation and state constraints

In this paper, input saturation and constraints of attack angle, sideslip angle and velocity deflection angle are taken into consideration in integrated guidance and control (IGC) design for skid-to-turn missile. The novel adaptive IGC scheme is proposed by combing dynamic surface control with barrier Lyapunov function (BLF). The BLF and modified saturation function are incorporated to prevent the constrained states from overstepping the constraints. To handle input saturation, auxiliary system is constructed. According to the stability analysis, all signals in closed-loop system are uniformly ultimately bounded while the constrained states remain in the constraint sets. The performance of the proposed adaptive IGC scheme is demonstrated by nonlinear numerical simulation results.

Neural Extended State Observer Based Intelligent Integrated Guidance and Control for Hypersonic Flight

Near-pace hypersonic flight has great potential in civil and military use due to its high speed and low cost. To optimize the design and improve the robustness, this paper focuses on the integrated guidance and control (IGC) design with nonlinear actuator dynamics in the terminal phase of hypersonic flight. Firstly, a nonlinear integrated guidance and control model is developed with saturated control surface deflection, and third-order actuator dynamics is considered. Secondly, a neural network is introduced using an extended state observer (ESO) design to estimate the complex model uncertainty, nonlinearity and disturbance. Thirdly, a command-filtered back-stepping controller is designed with flexible designed sliding surfaces to improve the terminal performance. In this process, hybrid command filters are implemented to avoid the influences of disturbances and repetitive derivation, meanwhile solving the problem of unknown control direction caused by nonlinear saturation. The stability of the closed-loop system is proved by the Lyapunov theory, and the controller parameters can be set according to the relevant remarks. Finally, a series of numerical simulations are presented to show the feasibility and validity of the proposed IGC scheme.

Integrated guidance and control for hypersonic vehicles in dive phase with multiple constraints

An adaptive integrated guidance and control (IGC) scheme for hypersonic vehicle in dive phase is proposed in this paper. The three dimensional (3D) coupling relative dynamics and the explicit relations between line-of-sight (LOS) angles and the angle of attack and sideslip angle are described based on analytical aerodynamic models of the hypersonic vehicle. A coupling and full states IGC design model in strict feedback form is derived by combing the 3D relative dynamics and the equations of the rotational loop. In the deduction of the novel IGC scheme, the 3D impact angles and constraints of the normal overload, commands of Euler angles and three-channel body rates are accounted for. The solution of a ten-order, nonlinear, and uncertain IGC frame control system is converted into an output tuning problem. Pseudo-inputs associated with rotational motion are depicted using adaptive dynamic surface control theory. The desired control surface fin deflections are derived based on the block dynamic surface approach. The Lyapunov function consisted of dynamic surfaces, errors of the filters, and estimation errors is conducted, states of the IGC closed-loop system are proved to be uniformly ultimate bounded. Finally, the effectiveness and robustness of the adaptive IGC scheme are investigated and verified using six-degree-of-freedom (6DoF) nonlinear simulation studies.