A tractor-trailer system is an underactuated system that is subject to nonholonomic constraints and exhibits extremely nonlinear behaviors. Its trajectory planning and control issues remain widely researched. In this paper, on the basis of establishing a precise kinematic model, a novel method is proposed to realize autonomous motion control of an off-axle hitching tractor-trailer system with a drawbar. The proposed method is roughly divided into three steps: EXTRACTING (E) a virtual subsystem, trajectory PLANNING (P) for the original full system, and trajectory TRACKING (T) by feedback control techniques, thus the “EPT method”. In the E step, two alternative strategies are considered to construct a virtual subsystem by extracting a part of an original towed aircraft system. Then, in the P step, a two-layer optimal control-based method is developed to generate a reference trajectory. Finally, in the T step, a receding horizon controller is designed to drive the carrier aircraft to track the reference trajectory under various external disturbances. Numerical experiments demonstrate that the EPT method is robust and highly efficient. The proposed method is also applicable for generalized tractor-trailer systems and other chain-link systems.

Based on the concepts of the reciprocal velocity obstacle (RVO) and Dubins methods, an improved Dubins-RVO method that can be applied to the scenario with noncircular obstacles is developed. Based on the Dubins-RVO method and one-sided Symplectic Pseudospectral method, a multiaircraft collaborative trajectory planning method was proposed. The kinematic constraint and terminal boundary conditions can be strictly satisfied in the proposed compound trajectory planning method. In addition, a symplectic pseudospectral receding horizon control (RHC) controller is designed to solve the trajectory tracking problem where the constraints on the state and control variables are considered. The proposed compound trajectory planning method is first applied to a two-aircraft problem. The obtained results demonstrate that compared to the RVO and Dubins-RVO methods, the proposed method can effectively avoid the “dead-lock” phenomenon and generate feasible trajectory efficiently satisfying all constraints. In addition, simulation experiment for four aircrafts is conducted. Smooth trajectories are obtained. Despite the presence of disturbances in the environment, the trajectories can be tracked with high precision using the symplectic pseudospectral RHC controller.

The efficient scheduling of carrier aircraft support operations in the flight deck is important for battle performances. The supporting operations and maintenance processes involve multiple support resources, complex scheduling process, and multiple constraints; the efficient coordination of these processes can be considered a multi-resource constrained multi-project scheduling problem (MRCMPSP), which is a complex non-deterministic polynomial-time hard (NP-hard) problem. The renewable resources include the operational crews, resource stations, and operational spaces, and the non-renewable resources include oil, gas, weapons, and electric power. An integer programming mathematical model is established to solve this problem. A periodic and event-driven rolling horizon (RH) scheduling strategy inspired by the RH optimization method from predictive control technology is presented for the dynamic scheduling environment. The periodic horizon scheduling strategy can track the changes of the carrier aircraft supporting system, and the improved event-driven mechanism can avoid unnecessary scheduling with effective resource allocation under uncertain conditions. The dual population genetic algorithm (DPGA) is designed to solve the large-scale scheduling problem. The activity list encoding method is proposed, and a new adaptive crossover and mutation strategy is designed to improve the global exploration ability. The double schedule for leftward and rightward populations is integrated into the genetic process of alternating iterations to improve the convergence speed and decrease the computation amount. The computational results show that our approach is effective at solving the scheduling problem in the dynamic environment, as well as making better decisions regarding disruption on a real-time basis.

Previous studies focused on deck-disposed and trajectory planning problem separately, and there was no systematic study from the whole process. This paper studied sortie scheduling for carrier aircrafts from the perspective of the whole scheduling and dispatch process. According to the process of sortie on flight deck, the sortie task was abstracted into six virtual stages, namely, deck-disposed, taxiing to preparing spot, taxiing from preparing spot to catapult, preparation on the catapult, takeoff, and cooling and recovery for the jet blast deflectors, and, the corresponding machines were also defined, respectively. The constraints were expressed, and the sortie scheduling model was build based on hybrid flexible flowshop scheduling. In addition, the one-sided symplectic pseudospectral method and the proposed collision avoidance strategy based on priority principle were combined to realize the collaborative trajectories planning of taxiing for multiple aircrafts. To obtain the optimal or near optimal solution, the double-layer genetic algorithm was proposed. Finally, the experiments were carried out based on the Nimitz-class aircraft carrier; the sortie task of 8 aircrafts under unknown conditions of deck-disposed and 13 aircrafts with fixed deck-disposed were studied, respectively. Experimental results show that the established model can well describe the sortie of aircraft, and it meets all constraints and actual requirements, which shows that the proposed method and the model can be used for sortie task effectively.