Optimal thrust vector control of tactical missiles

In vertical cold launch the missile starts without the function of the main engine. Over the launcher, the attitude of the missile is controlled by a set of lateral thrusters. However, a quick turn might be disturbed by various uncertainties. This study discusses the problem of the influences of disturbances and the repeatability of lateral thrusters’ ignition on the pitch maneuver quality. The generic 152.4 mm projectile equipped in small, solid propellant lateral thrusters was used as a test platform. A six degree of freedom mathematical model was developed to execute the Monte-Carlo simulations of the launch phase and to prepare the flight test campaign. The parametric analysis was performed to investigate the influence of system uncertainties on quick turn repeatability. A series of ground laboratory trials was accomplished. Thirteen flight tests were completed on the missile test range. The flight parameters were measured using an onboard inertial measurement unit and a ground vision system. It was experimentally proved that the cold vertical launch maneuver could be realized properly with at least two lateral motors. It was found that the initial roll rate of the projectile and the lateral thrusters ‘igniters’ uncertainties could affect the pitch angle achieved and must be minimized to reduce the projectile dispersion.

Sensitivity Analysis and Flight Tests Results for a Vertical Cold Launch Missile System

An optimal composite guidance strategy for vertically launched anti-skimmer RF missiles

This paper studies the optimization problem of agile-turn for the vertically launched missiles. The objective of this problem is to minimize the flight range. Compared with the previous studies, there are three major difficulties in solving this problem: (1) the problem is based on the six-degree-of-freedom dynamic model; (2) Due to the large angle attitude maneuvers, there exists singularity phenomenon of attitude in addition to the problem of strongly nonlinear coupling; (3) the missile adopts the integrated control system including thrust vector and tail fin controls, which causes that the nonlinear optimal control problem of the agile-turn is multiple-phased. The six-degree-of-freedom flight dynamics model of the missile is established in detail. Then the optimal control problem is solved by hp-adaptive Radau pseudospectral method. It is found that due to the disparity in the capability of attitude maneuvering, the missile uses the thrust vector control as the major mean to accomplish the agile-turn in the first flight phase. In the second flight phase, by operating the tail fins, the velocity and attitude of missile get stabilized and the terminal constraints are satisfied. The simulation results demonstrate the feasibility of agile-turn from vertical launch to attack ground targets, and the efficiency of the integrated control system.

Trajectory optimization for agile-turn of vertically launched missile

In order to solve the problem of rapid turning of missile vertical launch, the thrust vector control of jet vane is designed in this paper By applying the force analysis to the jet vane, the mathematical model of the missile's pitch motion in the vertical plane is established At the same time the jet vane controller is designed, which introducing the missile's pitch angle position control and rate control The simulation results show that the jet vane controller with the PID control rule can make the missile fast turn within one second The model of jet vane thrust vector control can effectively provide sufficient control torque for a missile's quick turn

Research on the thrust vector control via jet vane in rapid turning of vertical launch

This paper studies how a Differential Dynamic Programming (DDP) method can be used to compute optimal thrust vector controls for vertically launched missiles. Furthermore, the results of this investigation substantiate the practicality of a technique to control the convergence to overcome its difficulties with DDP. The problem under consideration requires the missile to perform a high-angle-of-attack maneuver. This, together with the control deflection limitation, implies nonlinear system dynamics. The optimal trajectories computed represent the performance that is possible to achieve given certain physical missile properties. The relative importance of different missile constraints is thus possible to compute.

H-O. Jonsson

Papers

Optimal Thrust Vector Control for Vertical Launch of Tactical Missiles