Guo Jifeng

Graph-based modeling and non-decoupling solution for distributed cooperative mission planning

This paper addresses the problems of autonomous task assignment and path planning for a fleet of heterogeneous unmanned aerial vehicles in cooperative mission. In previous work many algorithms almost run on centralized architecture and handle the task assignment decoupling with the path planning. This may result in poor solutions. Therefore, this paper investigates a novel integrated solution for UAV to perform multiple consecutive tasks cooperatively on multiple ground targets based on distributed planning architecture. In a given scenario, the heterogeneous vehicles have different capabilities, kinematic constraints, and fuel constraints. Furthermore, the task has other constraints, such as task execution orders, UAV conflict free constraints, etc. This paper presents details of the non-decoupling solution which produces optimal assignment and trajectories for several given scenarios. The performance of the algorithm is compared to that of some previous methods in real-time simulation environment. The simulations results show the viability of the non-decoupling approach, and the non-decoupling solution has an advantage over hierarchical algorithms, and the distributed architecture improves the operation efficiency of the algorithm and the robustness of the UAV.

TV guidance technical schemes for manned lunar soft landing

This paper researches the manually controlled site reselection focusing on the approaching phase and landing phase of soft landing of manned lunar landing. First, this paper introduces the phase division of manned lunar landing, establishes the kinetic model for lunar module and then makes research on the manual control site selection scheme under TV guidance. In the TV guidance scheme, the astronaut can directly select new lunar landing point within the field of view. The target guidance is achieved by automatic control system. Meanwhile, the impact of response delay of the astronaut on tasks in actual execution is considered. According to the simulation results of the guidance scheme, as the TV guidance is not restricted by the angle of sight, the adjustable range of the landing point is relatively great. Meanwhile, TV guidance has relatively great requirements on the attitude maneuver. In addition, the earlier the site reselection made by the astronaut, the greater the adjustable range of the landing point is.

Spacecraft attitude sliding mode control method design

The control of sliding mode variable structure has become one of an important in the modern control theories. It is also widely concerned by scholars at home and abroad due to its complete robustness such as its perturbation on system parameters, external disturbance and system uncertainty. This paper establishes the mathematical model for spacecraft based on error quaternion, derives the sliding-mode control law based on Lyapunov function by selecting appropriate sliding model and effectively weakens the buffeting by means of boundary layer approach. According to theoretical analysis and system simulation, the sliding-mode controller so designed is provided with robustness and overall stability under circumstances of parameter changes and external disturbances.