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In this paper, we present a novel multisensor combinatory attitude determination method that enables high-accuracy measurement of the attitude of a high rotational speed rigid-body aircraft. We analyze the external moments of the aircraft during flight and develop the method using theoretical deductions based on the motion equations of a rigid body rotating around the centroid. The proposed method fuses the data measured from GPS, gyrometer, and magnetometer and uses the improved unscented Kalman filter (UKF) algorithm to perform filtering. First, appropriate assumptions and simplifying approximations are made for around-centroid motion equations of a rigid body according to the motion characteristics of the high rotational speed aircraft. Using these assumptions and approximations, the constraint equations between the Euler attitude angles and flight-path angle, trajectory deflection angle are derived to serve as the state equation. Second, the roll angle with error is calculated using the geomagnetic field model and the geomagnetic intensity measured by a three-axis magnetometer and then fused with the angular velocity information obtained from the gyroscope for constructing the measurement equations. Finally, the state equations are discretized using the Runge–Kutta method during the UKF prediction stage, improving the prediction accuracy. Simulation results show that the proposed method can effectively determine the attitude information of the high rotational speed aircraft, achieving high level of reliability and accuracy thanks to the combination of information from GPS, gyroscope, and magnetometer.

For the lateral pulse-jet control problem of dual-spin projectiles, an intelligent optimal pulse-jet control strategy is proposed with 4-DOF impact point theory, BP neural network method and improved particle swarm optimization (IPSO) algorithm. The function of BP networks is designed to fit the control parameters and the impulse correction capability. And IPSO algorithm is utilized to deal with the optimization problem built by previous BP networks. Finally, numerical simulations are carried out to verify the effectiveness of the control system.

Considering nonlinear, multivariable coupling and parameter uncertainty in the nonlinear dynamic system of rotary rockets, an improved nonlinear disturbance observer (IDO) was proposed to approximate the high-frequency disturbance. A backstepping sliding mode controller is designed with the proposed disturbance observer to prevent cumulative tracking errors from guidance signals. The stability of this control system is proved with the Lyapunov function. The simulation results show the efficient performance of the backstepping sliding mode control with the proposed IDO method.

In this paper, the aerodynamic parameters identification strategy for high-spinning projectile with GPS and geomagnetic measurement data is proposed to obtain accurate aerodynamic parameters based on six-degree-of-freedom(6D) projectile model. Sensitivity functions are formulated and analyzed based on projectile system model, which is applied to the identification of aerodynamic parameters. Then an improved iterative Gauss-Newton method is adopted to conduct aerodynamic parameters identified formulation. The simulation results show the identification accuracy of estimated aerodynamic parameters using proposed strategy.

There are many problems in the design of attitude control system of vertical launched missile, such as system model nonlinearity, uncertainty, severe aerodynamic parameter perturbation and actuator response delay. Based on Active Disturbance Rejection Control (ADRC), an ADRC attitude controller is designed, which does not rely on accurate mathematical model and can dynamically compensate system model uncertainty and external disturbance. The performance of the controller is verified by using more accurate aerodynamic parameters of the missile. The simulation results show that the attitude controller can make the missile turn quickly and effectively. It can provide a reference for the design of similar missile control system.

This paper addresses the difficult problem of measuring the attitude of a high-spinning projectile and presents a novel method for estimating the pitch and yaw angles of the projectile in flight. The method is based on analysis of the external moment of the rotating projectile during flight and theoretical derivations obtained from the dynamics&rsquo, equations. First, the principle of zero-crossing method is introduced, which explains the process of geomagnetic azimuth and roll measurements by the non-orthogonal geomagnetic sensor combination. Then, the dynamics constraint equations between the Euler angles and flight-path angle, trajectory deflection angle of the projectile are derived using the dynamics equations of the projectile rotating around the centroid, and analysis of the flight characteristics of the projectile in stable flight. Next, the spatial orientation relationship between pitch, yaw angles and magnetic azimuth is established based on the physical principle of geomagnetic azimuth. Finally, the pitch and yaw angles are estimated using the unscented Kalman filter (UKF), with the dynamics constraint equations serving as the driving equations. In the UKF prediction stage, the Runge-Kutta method is used to discretize the state equation that improves the prediction accuracy. Simulation results show that the proposed method can be used to accurately calculate the pitch and yaw angles, and results of experimental data processing also verify the feasibility of the proposed method for real-world applications.

In this article, a robust attitude control scheme, which is called sliding mode control with unidirectional auxiliary surfaces (UAS-SMC), is proposed for the near-space vehicle with attitude constraints and time-varying unknown disturbance. Firstly, the positively invariant sets are designed with the UAS-SMC method. The invariant property of these sets can be utilized to guarantee the attitude constraints. Secondly, a UAS nonlinear disturbance observer is firstly developed for the NSV with time-varying unknown disturbance. By introducing the information of UAS surfaces, the performance of this observer is enhanced. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust UAS-SMC scheme. Finally, simulation results are given to illustrate the effectiveness of the proposed attitude control scheme.

In this paper, the sliding mode control with uni-directional auxiliary surface (UAS-SMC) is proposed for Gun-launched UAV with chattering alleviation and attenuation. The necessary definitions in UAS-SMC method is given to show the detailed information of this method. And relationship between UAS-SMC and traditional SMC method is presented to clearly understand the UAS-SMC theory. Then, a discontinuous UAS-SMC controller is designed to solve the tracking problem of Gun-launched UAV. The simulation results are given to illustrate the performance of UAS-SMC controller.

For the spin stabilized two-dimensional trajectory correction projectiles with utation and precession phenomenon, an attitude controller with sliding mode control method and unidiational auxilairy surfaces (UAS-SMC) is proposed in this paper. And the underactuated control allocation in two-dimensional trajectory correction projectile with UAS-SMC controller is also discussed here. Simulation results show that the proposed controller can effectively control the attitude of the projectile and has strong robustness, which provides reference for engineering applications.

A robust adaptive backstepping attitude control scheme, combined with invariant-set-based sliding mode control and fast-nonlinear disturbance observer, is proposed for the airbreathing hypersonic vehicle with attitude constraints and propulsive disturbance. Based on the positive invariant set and backstepping method, an innovative sliding surface is firstly developed for the attitude constraints. And the propulsive disturbance of airbreathing hypersonic vehicle is described as a differential equation which is motivated by attitude angles in this paper. Then, an adaptive fast-nonlinear disturbance observer for the proposed sliding surface is designed to estimate this kind of disturbance. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust attitude control scheme. Finally, simulation results are given to illustrate the effectiveness of the proposed attitude control scheme.