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The Capacitated Vehicle Routing Problem (CVRP) is a well-known NP-hard problem of importance to real life applications such as transportation and logistics. The CVRP finds the best set of paths between a specific number of customers to deliver goods by a number of vehicles with a fixed capacity. In this paper, we apply a new nature inspired optimization algorithm called Intelligent Water Drops (IWD)...
Although it is effective in realistic path loss prediction to consider propagation path shadowing by the vehicles which run a roadway in development of the various ITS in a city area road, it is further required in development of pedestrian-to-vehicle communications that the path loss model which can take into consideration the influence of path shadowing due to pedestrians moving on a sidewalk. This...
An auto-landing guidance law on the basis of sliding mode control (SMC) is presented in this paper for landing an unpowered reusable launch vehicle (URLV) at the predetermined landing site. The guidance scheme, which takes the full nonlinear point-mass dynamics into account, is developed in three-dimensional space. For the sake of dealing with large initial condition errors, the guidance process is...
Precision of vehicle navigation can be significantly improved by adding motion constraints. How to model multi-motion constraints and choose appropriate motion constraint according to vehicle mobility need to be solved in practical usage. This article established a unified state error model and deduced a measurement model for several common vehicle motion constraints, like ZUPT, MCA and HDR, used...
In this paper, a fusion CKF algorithm with TDRS (Tracking and Data Relay Satellite) and ground stations is presented for a micro reentering USV (Unmanned Space Vehicle). A micro reentering USV has high lift-drag ratio and maneuverability, unlike traditional reentry vehicle, is hard to track. In order to solve this problem, a fusion strategy of CKF (Cubature Kalman Filter) with multi-sensors is estimated...
Space applications have raised the demand on autonomy, security and reliability for current reusable launch vehicle (RLV), which require guidance technology of vehicle must have strong robustness and adaptability. Based on preliminary research results, this paper outlines a method of developing an online predictive reentry trajectory planning and guidance law which use both angle-of-attack and angle-of-bank...
An integrated navigation method of strapdown inertial navigation system(SINS) and odometer basing on Kalman filter was introduced. In the integrated navigation, error of SINS, inertial measurement unit(IMU) and odometer could be estimated and compensated online. Based on the integrated navigation measurement equation, together with the combining typical maneuver of land vehicle and error propagating...
In this paper, an integrated fault-tolerant guidance and control scheme is proposed for reentry hypersonic vehicles. Firstly, a predictor-corrector reentry guidance controller in guidance loop is designed for guidance commands to generate the desired angle of attach and bank angle commands that satisfy the reentry constraints. Then, a backstepping control algorithm is designed for attitude loop to...
A new guidance law with terminal trajectory angle constraint is designed for bank to turn flight vehicle, which aims at the fixed position ground target. The general form of guidance law with sight angle and sight angle velocity as feedback variables is presented, and the stability of it is proved via finite time convergent stability theory, which makes traditional optimal guidance as a specific example...
The response characteristics of the moving-mass controlled flying vehicle is researched based on the moving-mass control system model of the flying saucer. Simulation results show that when the vehicle flies in the thick atmosphere at low altitude, the states of the vehicle are disturbed by the movement of the sliding mass block, but the disturbance does not appear when the vehicle flies at superhigh...
A new longitudinal trajectory tracking law for the Terminal Area Energy Management (TAEM) phase of the Reusable Launch Vehicle (RLV) is presented in this paper. The conventional PID method controls the height and the velocity by the angle of attack and the angle of airbrake respectively, and no coupling is considered. To improve the tracking precision, the new tracking law is designed based on the...
A quick analysis approach based on Pontryagin principle is proposed to calculate the maximum cross-range, and the lateral accessible region in the new redefined coordinate is analyzed. The order and non-linearity of the point-mass motion function is reduced by coordinate transformation and replacing the independent variable, the trajectory optimization is cast as an optimal control problem, then the...
In this paper, a dynamic surface control strategy based on extended state observer is proposed for reentry attitude control of hypersonic vehicles with the presence of external disturbances and modeling uncertainties. Firstly, according to time scale, the system is divided into two parts, i.e. the inner subsystem and outer subsystem. Secondly, based on the hierarchical idea, two extended state observers...
Focusing on lateral stability control of vehicle, this paper presents a braking control approach for vehicles cornering or changing path based on sliding mode control strategy. The proposed braking control makes vehicle system track the desired yaw rate and side slip angle while the corresponding situation. The controller is consisted of three parts. The upper controller is an effective yaw moment...
This paper presents a sliding mode based longitudinal guidance scheme for Unmanned Aerial Vehicles (UAVs). A nonlinear sliding surface is proposed here for altitude control of UAVs. Longitudinal guidance law based on traditional linear sliding surface cannot provide good performance for both large and small errors in altitude, hence a non-linear surface is proposed here. The proposed sliding surface...
Quadrotor helicopters have been the focus of many research works during the last decade. Thanks to their numerous appealing features, their applications are increasingly reported in the literature. Their main limitation, however, is their lightweight which makes them sensitive to external disturbances. The aim of this paper is to achieve robust trajectory following for a Quadro-UAV, in the presence...
In this paper, we present an extension to a recently developed continuous-time, finite-time parameter estimation structure to perform data fusion. The regression elements of the finite-time algorithm are used to carry additional infor-mation. Their parameters are also parameters in the dynamics of additional sensors. This additional information will help in estimating these parameters. The algorithm...
Quadrotors low level control has attracted the attention of many research works over the last decade. In most of previous works, position stabilisation was achieved using nonlinear control techniques. In this paper, two full linear techniques based on optimal control theory are presented. The first, based on the L2 norm, is a Linear Quadratique Servo (LQ-Servo) controller. The second one, optimizes...
The g uidance of a launch vehicle with constraints on the impact point of the spent stages is discussed. Guidance equations for a flat Earth based model is studied and an analytical optimization algorithm called FE guidance algorithm is validated for honoring the targeted states even under the circumstances of modified initial conditions. The splash down constraint can be imposed into this existing...
Because of particular dynamic characteristics, the traditional method for calculating weight matrices in LQR is not suitable for reentry vehicle profile-following. This paper designs parameter varying weight matrix. In this method, on the basis of vehicle entry flight characteristics, we design the functional relationship between weight matrix parameters and flight states. The simulations show that...
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