Trajectory Planning and Control for Longitudinal Maneuvers of UCAV

In addressing the problem of trajectory planning for longitudinal maneuvers of Unmanned Combat Aerial Vehicles(UCAV), we consider the process of maneuvers, the flight constraints, and decision-making layer requirements, transforming this problem into optimal control problems. To solve this optimal control problems, the Gauss Pseudo-Spectral Method(GPM) is employed. As a result, the maneuver trajectory is planned, characterized by a time series of state variables and control variables. To achieve precise tracking control of the planed trajectory, a flight control structure with inner-outer loop is designed. The outer-loop generates compensatory control inputs based on the deviation between the actual and planned positions of the UCAV, while the inner-loop precisely tracks the sum of the planned control inputs and the compensatory inputs. The inner-loop employs Linear Active Disturbance Rejection Control(LADRC) to track commands precisely over a wide flight envelope. The outer controller adopts a Guidance Method Based on Position Deviation Vector Decomposition(PDVD Guidance Method) to achieve precise tracking control of the maneuver trajectory, covering large attitude angles. Finally, trajectory planning and trajectory tracking control simulations for a UCAV were conducted for longitudinal maneuver. The results indicate that the maneuver trajectory planning algorithm can effectively plan trajectories that meet requirements, and the maneuver trajectory tracking control can accurately track the planned trajectories throughout the entire maneuvering flight.