Time-coordinated re-entry trajectory planning for hypersonic glide vehicle cluster

With the rapid development of anti-missile technology, the survivability of individual vehicles can no longer meet the increasingly complex mission requirements of the future. Therefore, the planning of the reentry timing and trajectory of multiple vehicles will be the primary focus of future research aimed at achieving effective collaboration between time and space. However, the existing studies mainly has the following shortcomings:

1) Related studies typically focus on the simultaneous terminal arrival scenario while neglecting other cooperative scenarios. Furthermore, these studies fail to account for the effects of multiple no-fly zone constraints on cooperative trajectories, which is not consistent with the actual mission scenario.

2) In order to improve the efficiency of cooperative planning, related studies typically establish the angle of attack and the angle of bank as fixed profiles. However, the design of fixed profile limits the maneuverability of the vehicle.

Aiming at the shortcomings of existing studies, a time-cooperative re-entry trajectory planning method for hypersonic gliding vehicles was proposed. First, the re-entry dynamics model for the vehicle cluster was established, and a longitudinal trajectory control scheme was designed based on control volume and re-entry corridor constraints. Secondly, a trajectory planning scheme that incorporates two forms of cooperation was proposed. This scheme was based on the mission requirements of the vehicle cluster and the analysis of the gliding capabilities of each vehicle, which were utilized to determine the cooperative time. Finally, hp adaptive solution strategy, under fixed time constraints, was adopted to facilitate the rapid planning of the cooperation trajectory.

Numerical simulation experiments were conducted using a cluster of three vehicles. The effectiveness of the proposed method is validated in two typical cooperative scenarios: multiple vehicles re-entry the atmosphere simultaneously from different starting points, avoid multiple no-fly zones concurrently, and arrive at the mission area sequentially according to a defined schedule. A cluster of vehicles re-entry from the same starting point, with sequential arrivals achieved by controlling the glide time of each vehicle. The results indicate that a single vehicle can successfully avoid entering multiple no-fly zones through lateral maneuvers. Ultimately, the cluster of vehicles will collaborate to reach the designated target point, significantly improving their survivability. In addition, compared to the existing control scheme for longitudinal trajectory, the method proposed in this paper significantly improves the planning speed of cooperative trajectories. The control scheme improves the adjustable glide time range of the cluster by approximately 21.43%, while simultaneously addressing the challenges posed by the complex re-entry environment and meeting the requirements of the cooperative mission.

1) A time-coordinated re-entry trajectory planning method is proposed to fulfill the mission requirements of hypersonic vehicles. A control scheme for longitudinal trajectory has been developed, and two cooperation trajectory planning scenarios are introduced to address the multi-vehicle trajectory planning problem within specified time constraints.

2) The study focused on practical mission scenarios, considering the limitations of the complex re-entry environment and the necessity of avoiding no-fly zones. The gliding capability and time-adjustment range of the vehicle were analyzed to meet various cooperative requirements.

3) The effectiveness of the proposed method is validated through simulations conducted under two cooperative re-entry scenarios. This method improves the efficiency of cooperative trajectory planning while ensuring the robust maneuverability of each vehicle.