Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally intractable.This paper proposes a Safe Flight Corridor constrained Sequent...Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally intractable.This paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory generation.SFC-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free waypoints.Via transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation complexity.Then,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem complexity.In addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve efficiency.Simulation experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory rapidly.Comparative studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of SFC-SCP.Besides,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time.展开更多
Uncertain factors such as atmospheric density,aerodynamic coefficients,and aircraft mass can have a catastrophic impact on the flight safety of entry vehicles(EVs).It is crucial for EVs to quickly generate safe entry ...Uncertain factors such as atmospheric density,aerodynamic coefficients,and aircraft mass can have a catastrophic impact on the flight safety of entry vehicles(EVs).It is crucial for EVs to quickly generate safe entry trajectories that consider the impact of uncertainties to execute complex flight tasks such as online target changing.Given this challenge,a rapid generation method of safe entry trajectories is proposed,which is based on the drag-acceleration-profile method employed during space shuttle entry flights.This method can efficiently generate a safe,feasible trajectory while accounting for the influence of uncertain factors.Compared to traditional drag-acceleration-profile methods,the proposed method incorporates the influence of uncertain factors on the boundaries of the flight corridor.It establishes an uncertain flight corridor model,thereby ensuring the safety of the reference flight profile designed within this corridor under actual uncertain flight conditions.Additionally,a simplified design approach for the reference flight profile enables the rapid generation of satisfactory profiles through straightforward parameter iteration or optimization.Simulations demonstrate that this method can efficiently plan gliding flight trajectories that meet safety requirements,exhibiting potential for online trajectory generation and maneuverability assessment.展开更多
基金supported by the National Natural Science Foundation of China(No.62203256)。
文摘Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally intractable.This paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory generation.SFC-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free waypoints.Via transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation complexity.Then,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem complexity.In addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve efficiency.Simulation experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory rapidly.Comparative studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of SFC-SCP.Besides,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time.
基金supported by the National Nature Science Foundation of China(92271108,62173336)
文摘Uncertain factors such as atmospheric density,aerodynamic coefficients,and aircraft mass can have a catastrophic impact on the flight safety of entry vehicles(EVs).It is crucial for EVs to quickly generate safe entry trajectories that consider the impact of uncertainties to execute complex flight tasks such as online target changing.Given this challenge,a rapid generation method of safe entry trajectories is proposed,which is based on the drag-acceleration-profile method employed during space shuttle entry flights.This method can efficiently generate a safe,feasible trajectory while accounting for the influence of uncertain factors.Compared to traditional drag-acceleration-profile methods,the proposed method incorporates the influence of uncertain factors on the boundaries of the flight corridor.It establishes an uncertain flight corridor model,thereby ensuring the safety of the reference flight profile designed within this corridor under actual uncertain flight conditions.Additionally,a simplified design approach for the reference flight profile enables the rapid generation of satisfactory profiles through straightforward parameter iteration or optimization.Simulations demonstrate that this method can efficiently plan gliding flight trajectories that meet safety requirements,exhibiting potential for online trajectory generation and maneuverability assessment.
