Hypersonic Target Research Articles

Design of Head-Pursuit Guidance Law Based on Backstepping Sliding Mode Control

In order to meet the needs of high-precision guidance for intercepting hypersonic targets, a novel head-pursuit guidance law considering the dynamic characteristics of a missile control system and the target mobility is presented via combining a fast power reaching law with backstepping sliding mode control in this paper. Initially, a three-dimensional head-pursuit system model of the missile and target is established. Subsequently, the system model is decomposed into a pitch plane system and lateral plane system, the control system dynamics are equivalent to second-order systems, and finite-time disturbance observers are introduced to estimate the target accelerations. On the basis of the previous work, the head-pursuit guidance laws of the vertical system and the lateral system which can stabilize the closed-loop system are designed separately and strict proofs of the methods are given. Finally, simulations are carried out to verify the effectiveness of this head-pursuit guidance law.

Near‐space hypersonic target coherent integration algorithm based on search compensation

A near-space hypersonic target coherent integration algorithm based on search compensation is proposed for the problem of range gate stride and Doppler extension. The algorithm first estimates the target radial velocity and Doppler rate by searching, and then completes coherent integration of echo signal via distance and phase compensation according to the estimated values. The simulation results show that the algorithm can effectively solve the problem of range gate stride and Doppler extension, suppress noise, and increase gain. The integration effect of the proposed algorithm is obviously superior to the classical moving target detection (MTD) algorithm.

Suboptimal Midcourse Guidance with Terminal-Angle Constraint for Hypersonic Target Interception

For the problem of hypersonic target interception, a novel midcourse guidance method with terminal-angle constraint is proposed. Referring to the air-breathing and the boost-gliding hypersonic targets, flight characteristics and difficulties of interception are analyzed, respectively. The requirements of midcourse guidance for interceptors are provided additionally. The kinematics model of adversaries is established concerning line-of-sight coupling in longitudinal and lateral planes. Suboptimal guidance law with terminal-angle constraint, specifically the final line-of-sight angle or impact angle, is presented by means of model predictive static programming. The trajectory is optimized and the load factor would finally converge after penalizing control sequence and output deviations. The realization of terminal angle is firstly verified with a constant speed target. A full interception scenario is further simulated focusing on a typical boost-gliding target, which flies along a skipping trajectory. Results show the success of providing handover conditions for intercepting hypersonic targets.

Hypersonic reentry gliding target tracking based on AVSIMM algorithm

Hypersonic reentry gliding target tracking based on AVSIMM algorithm

Hypersonic Target Tracking With High Dynamic Biases

The chirp signal, which is of large time bandwidth product, is widely used in the current radar systems. However, high dynamic biases are brought into the radar ranging when the signal is used in the hypersonic target tracking, due to the distance-Doppler coupling. In view of the situation, this letter proposes an unbiased tracking algorithm which can eliminate the influence of high dynamic biases at the same time of target tracking.

高超声速目标相干双频激光雷达探测技术

高超声速目标相干双频激光雷达探测技术

A Variable-Diameter-Arc-Helix Radon Transform for Detecting a Near Space Hypersonic Maneuvering Target

For detection and tracking of a near space hypersonic maneuvering target in a heavy clutter environment, a novel transform domain method called Variable-Diameter-Arc-Helix Radon Transform (VDAH-RT) is proposed as a tool to integrate observations along the maneuvering path. Considering the 3D maneuvering trajectory is like a variable diameter arc helix, the trajectory of near space hypersonic target can be modeled by a variable diameter arc helix. Since the maneuvering parameters are unknown, variable diameter arc helixes with different parameters can be used to match the maneuver track. Using the idea of Radon Transform(RT), the problem of maneuvering trajectory detection and tracking is transformed into the energy peak detection problem in VDAH-RT parameter domain. This Variable-Diameter-Arc-Helix Radon Transform (VDAH-RT) technique extends the RT or HT(Hough Transform) for straight-line features detection to an arbitrary curve trajectory. The results demonstrate that the proposed algorithm provides great advantage in the detection and tracking of a hypersonic maneuvering dim target.

Coverage-based cooperative target acquisition for hypersonic interceptions

This paper presents a novel coverage-based cooperative target acquisition algorithm for hypersonic interceptions. Firstly, the difficulties in the hypersonic trajectory prediction are introduced which invalidate the conventionally used predicted impact point based mid-course guidance and seeker acquisition. Secondly, in order to optimally estimate and predict the target trajectory information, the interacting multiple model (IMM) algorithm is used with the constant velocity (CV) model, the constant acceleration (CA) model and the Singer model serving as the model set. The target states are described with the probability density function (PDF) based on the IMM prediction. Thirdly, the interceptor seeker target acquisition model is established which considers the blur edge region of the field of view. The cooperative target acquisition algorithm is designed by maximizing the interceptor seekers cooperative coverage of the target high probability region (HPR). Finally, digital simulations prove the effectiveness of the proposed method and reveal that the real challenge in the hypersonic target acquisition is the poor trajectory prediction accuracy which may further result to the unsteadiness of the interceptor trajectories.

A tracking algorithm of hypersonic target based on dynamic model and square-root cubature Kalman filter

Because of the complexities of target motion features, the tracking of hypersonic target in near space is difficult. In this paper, a new adaptive tracking algorithm based on dynamic model and improved square-root cubature Kalman filter(SRCKF) is proposed. According to the target movement characteristics, the improved adaptive piecewise constant Jerk model is proposed based on the dynamic model. The improved square-root cubature Kalman filter which the model mismatch detection function is introduced to reduce the state estimation error. The simulation results indicate that the proposed method which combines the model and the estimation algorithm has higher accuracy and stability on maneuvering target tracking than other existing methods. The research provides a feasible solution to the further improvement of the real time tracking accuracy of near-space hypersonic target.

PO calculation for reduction in radar cross section of hypersonic targets using RAM

The radar cross section (RCS) reduction of hypersonic targets by radar absorbing materials (RAM) coating under different reentry cases is analyzed in the C and X bands frequency range normally used for radar detection. The physical optics method is extended to both the inhomogeneous plasma sheath and RAM layer present simultaneously. The simulation results show that the absorbing coating can reduce the RCS of the plasma cloaking system and its effectiveness is related to the maximum plasma frequency. Moreover, the amount of the RCS decrease, its maxima, and the corresponding optimal RAM thickness depend on the non-uniformity and parameters of the plasma sheath. In addition, the backward RCS of the flight vehicle shrouded by plasma shielding and man-made absorber is calculated and compared to the bare cone.

Infrared measurement and composite tracking algorithm for air-breathing hypersonic vehicles

Air-breathing hypersonic vehicles have capabilities of hypersonic speed and strong maneuvering, and thus pose a significant challenge to conventional tracking methodologies. To achieve desirable tracking performance for hypersonic targets, this paper investigates the problems related to measurement model design and tracking model mismatching. First, owing to the severe aerothermal effect of hypersonic motion, an infrared measurement model in near space is designed and analyzed based on target infrared radiation and an atmospheric model. Second, using information from infrared sensors, a composite tracking algorithm is proposed via a combination of the interactive multiple models (IMM) algorithm, fitting dynamics model, and strong tracking filter. During the procedure, the IMMs algorithm generates tracking data to establish a fitting dynamics model of the target. Then, the strong tracking unscented Kalman filter is employed to estimate the target states for suppressing the impact of target maneuvers. Simulations are performed to verify the feasibility of the presented composite tracking algorithm. The results demonstrate that the designed infrared measurement model effectively and continuously observes hypersonic vehicles, and the proposed composite tracking algorithm accurately and stably tracks these targets.

Calculation Method of Hypersonic Target Irradiance Based on Grid

Calculation Method of Hypersonic Target Irradiance Based on Grid

Calculation Method of Hypersonic Target Irradiance Based on Grid

Calculation Method of Hypersonic Target Irradiance Based on Grid

A NEW ADAPTIVE TRACKING ALGORITHM FOR NEAR-SPACE HYPERSONIC TARGET

A NEW ADAPTIVE TRACKING ALGORITHM FOR NEAR-SPACE HYPERSONIC TARGET

Radon-S transform for hypersonic maneuvering target detection

Hypersonic maneuvering target can cause complex range migration and Doppler frequency migration effects even in a very short time. This brings a big challenge to the common long-time coherent integration based target detection methods. To solve this problem, a novel hypersonic maneuvering target detection method called Radon-S transform is proposed in this paper on the basis of Radon transform and S-transform. It performs the coherent integration along the target track on the time–range plane, and then performs the non-coherent integration along the time–frequency curve of target echo on the time–frequency plane. By combining the two energy integration processes, the signal-to-noise/clutter ratio can be effectively improved. The definition of Radon-S transform, the concrete realization of detection process, and the setting of correlative parameters are introduced in detail. Then the performance of Radon-S transform is analyzed in theory. Finally, numerical experiment results show that the proposed method is superior to some common long-time coherent integration methods in the hypersonic maneuvering target detection.

Iterative Learning Control for homing guidance design of missiles

Abstract This paper presents an Iterative Learning Control design applied to homing guidance of missiles against maneuvering targets. According to numerical experiments, although an increase of the control energies is appreciated with respect to a previous published base controller for comparison, this strategy, which is simple to realize, is able to reduce the time to reach the head-on condition to target destruction. This fact is important to minimize the missile lateral force-level to fulfill engaging in hyper-sonic target persecutions.

Hypersonic sliding target tracking in near space

To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF) coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA), constant turning (CT) and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

Tracking Algorithm Design and Comparison of High Speed High Maneuvering Target

Aiming at the problem that the traditional tracking method cannot track high speed high maneuvering target effectively, one modified fixed structure multiple model algorithm (M-FSMM) and one modified variable structure multiple model (M-VSMM) algorithm were proposed. The Constant Velocity (CV) model, Current Statistical (CS) and Modified Coordinate Turn (MCT) model were adopted in the M-FSMM algorithm, by means of Connected Graph (CG) thinking, the model connected graph was made up by models that can describe possible motion, the connected relation was set up and model self-adapting was designed to carry out the variable structure tracking that can quickly jump between models. Monte Carlo simulation results show that the two methods can track high speed high maneuvering target effectively, the computational quantum of M-FVMM algorithm is larger but the tracking accuracy and stability are better than the M-FSMM algorithm. They can be used to track near space hypersonic targets.

MPD model for radar echo signal of hypersonic targets

The stop-and-go (SAG) model is typically used for echo signal received by the radar using linear frequency modulation pulse compression. In this study, the authors demonstrate that this model is not applicable to hypersonic targets. Instead of SAG model, they present a more realistic echo signal model (moving-in-pulse duration (MPD)) for hypersonic targets. Following that, they evaluate the performances of pulse compression under the SAG and MPD models by theoretical analysis and simulations. They found that the pulse compression gain has an increase of 3 dB by using the MPD model compared with the SAG model in typical cases.

Interacting Multiple Mode Tracking Algorithm Based on Modified Coordinate Turn Model

The continuing success of near space hypersonic aircraft flight test has become a real threat to China's space attack-defense system, In view of the problem that the single model cannot track such target effectively, an interacting multiple model (IMM) tracking algorithm based on modified cornering model (MCT) was proposed. First the characteristics of near space hypersonic target were analyzed, and then the target real-time angular velocity according to the target motion equation was estimated, finally the near space hypersonic target tracking through the IMM was carried out. The Monte Carlo simulation results show that the IMM tracking algorithm can effectively track near space hypersonic target, and the tracking accuracy and stability are superior to single model, it has certain practical significance.