Research On Guidance And Control Of Moving Mass Actuated Vehicle

Fundamentally,the maneuver of missile is achieved via altering control moment,which could be classified into two categories: adjusting the magnitude of control force and changing the arm of control force.Traditional rudder control and jet thrust control belong to the first category.However,rudder control fails to solve the ablation problem when the missile is flying with high speed.And jet thrust control is subject to the limited fuel capacity and the solid-liquid coupling.Moving mass control belongs to the second category.With actuators inside the missile,there will be no actuator ablation.And with no need for fuel,the working time of the actuator will be prolonged and solid-liquid coupling is avoided.Therefore,compared with traditional control modes,moving mass control has its obvious edge and broad application.However,due to its unique control mechanism,spacial motion equations of moving mass actuated vehicle are much more complicated,which brings about many new challenges in the designing of guidance and control system.In the background of reentry maneuvering and accurate attacking of moving mass actuated vehicle,this dissertation aims at addressing the modeling and guidance-and-control-system designing of skid-toturn(STT)vehicle actuated by two moving masses and a pair of difference ailerons,achievements of which strengthen the theoretical support for the development of moving mass actuated missile.Firstly,adopting the modeling method of multi rigid body system,complete spacial motion models of STT reentry vehicle actuated by two moving masses and a pair of difference ailerons are built.Considering the kinematic coupling,inertial coupling and aerodynamic-inertial cross coupling,translational dynamic equations of missile centroid are built under missile-body coordinate system based on the momentum theory,and rotational dynamic equations of missile centroid are built under missile-body coordinate system based on the angular momentum theory.Meanwhile,the translational and rotational kinematic equations of missile centroid are established under reentry coordinate system.These equations fully describe the mechanism of spacial movement of moving mass actuated vehicle,revealing the inner relationship between the motion of the moving mass and the translational and rotational motion of missile centroid.Compared with that of traditional rudder control and jet thrust control,spacial motion models of moving mass control are much more complicated due to its unique control mechanism,that is,the inner coupling between the motion of the moving mass and that of the missile body.Secondly,aiming at attacking steady ground targets accurately,finite-r convergent guidance laws both with and without impact angle constraint are proposed respectively.1)A novel guidance model is established,in which lineof-sight distance is treated as independent variable to describe the relative motion between the missile and the target.The guidance model includes two differential equations that describe the dash motion and the turning motion of line-of-sight respectively and the differential equation of line-of-sight dash motion is separately decoupled.The design of guidance law based on this novel guidance model not only maintains the accuracy but also simplifies the guidance law design.2)Based on the novel guidance model,finite –r convergent guidance laws with interference suppression of the dash and turning motion of line-of-sight are designed respectively,which are presented in the form of normal overload.Compared with traditional guidance laws,the proposed one guarantees that lineof-sight angular rate converges to zero before line-of-sight distance decreases to the desired value.The correctness and validity of the guidance model and guidance law are verified by numerical simulation.3)Based on the novel guidance model,finite –r convergent guidance laws with impact angle constraint of the dash and turning motion of line-of-sight are designed respectively,which are presented in the form of normal overload.Compared with traditional guidance laws,the proposed one guarantees that line-of-sight angular rate converges to zero and line-of-sight angle converges to the commanding impact angle before line-of-sight distance decreases to the desired value.Comparisons of simulation results among PNG,ONG and the proposed guidance law demonstrate the correctness and advantages of the novel guidance model and guidance law.Then,aiming at attitude control of moving mass actuated vehicle,finite time convergent control law both with and without input saturation are proposed respectively.1)Under proper hypothesis and simplification,three-channel independent attitude control models of pitch,yaw,and roll motion of moving mass actuated vehicle are established respectively.Based on the models above,finite time convergent attitude control laws of those three channels are designed respectively.Compared with traditional control laws of moving mass actuated vehicle,the proposed one guarantees that attitude angle deviation and its derivative converge to the neighborhood of origin in finite time.2)By introducing in extended state observer to estimate disturbance boundary adaptively,finite time convergent attitude control laws with input saturation of those three channels are designed respectively.Compared with traditional control laws of moving mass actuated vehicle,the proposed one guarantees that the deviation of attitude angle and its derivative converge to the neighborhood of origin in finite time even under the saturation of control input.Numerical simulations of characteristic point and the whole flight are carried out respectively,demonstrating the correctness and validity of proposed finite time convergent attitude control law both with and without input saturation.Finally,aiming at attacking escaping ground target accurately,three-channel independent and three-channel coupling integrated guidance and control are proposed respectively.1)Three-channel independent integrated guidance and control models of pitch,yaw,and roll motion of moving mass actuated vehicle are built.Based on robust adaptive back-stepping method,an integrated guidance and control algorithm is designed,in which robust adaptive function is introduced in to compensate for bounded disturbance adaptively.The “compute explosion” problem that is common in traditional back-stepping control is avoided by nonlinear tracking differentiator.It is theoretically proved that statetracking errors and disturbance estimation errors converge to the neighborhood of origin exponentially.Numerical simulation results demonstrate the correctness and validity of proposed three-channel independent integrated guidance and control model and algorithm.2)Three-channel coupling integrated guidance and control model of pitch,yaw,and roll motion of moving mass actuated vehicle is built.Based on adaptive block dynamic surface control,an integrated guidance and control algorithm is designed,in which robust adaptive function is introduced in to compensate for bounded disturbance.The “compute explosion” problem that is common in traditional back-stepping control is avoided by dynamic surface technology.It is theoretically proved that state-tracking errors,boundary layer deviation and disturbance-estimation errors converge to the neighborhood of origin exponentially.Numerical simulation results demonstrate the correctness and validity of proposed three-channel coupling integrated guidance and control model and algorithm.