scholarly journals Time-varying formation dynamics modeling and constrained trajectory optimization of multi-quadrotor UAVs

Author(s):  
Xi Li ◽  
Guoyuan Qi ◽  
Limin Zhang
2021 ◽  
Author(s):  
Xi Li ◽  
Guoyuan Qi ◽  
Limin Zhang

Abstract The formation of multiple quadrotor UAVs with long navigation will encounter many flight constraints, so it is necessary to change the formation to avoid these constraints. In this paper, Voronoi graph theory is used to treat UAVs formation as a rigid body. The rigid body structure can be changed by changing the formation before different constraints, after passing constraints the rigid body structure remains the formation unchanged or form into the prescribed formation. The time-varying model is established to facilitate the use of optimization. Based on Gauss pseudospectral method (GPM), the path optimization of a single quadrotor UAV is carried out. The followed UAVs in formation are treated as constraints. The constraints of maximum turning radius and formation transformation time of other UAVs are considered in the optimization process. The minimum time required for formation transformation is optimized to solve the transformation optimization, and the performance index of trajectory optimization is to minimize the energy consumed by the leader quadrotor UAV within the specified time. Finally, the simulation proves the method proposed in this paper.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Hui Zhang ◽  
Wenbin Zha ◽  
Xiangrong Xu ◽  
Yongfei Zhu

Aiming at the impact and disturbance of dual-arm robots in the process of coordinated transportation, a dual-arm cooperative trajectory optimization control based on time-varying constrained output state is proposed. According to the constraint relationship of the end-effector trajectory of the dual-arm coordinated transportation, the joint space trajectory mathematical model of the dual-arm coordinated transportation was established by using the master-slave construction method. Based on the time impact optimization index of joint trajectory, a multiobjective nonlinear equation is established. Using random probability distribution to extract the interpolation features of nonuniform quintic B-spline trajectory, the feature optimization target is selected, and the Newton numerical algorithm is used for iterative optimization. At the same time, it is combined with an elite retention genetic algorithm to further optimize the target. Based on the disturbance and tracking problem, a PD control method based on time-varying constrained output state is proposed, and the control law is designed. Its convergence is verified by establishing the Lyapunov function equation and asymmetric term. The trajectory optimization results show that the proposed trajectory optimization method can increase the individual diversity and enhance the individual local optimization, thus avoiding the premature impact of the elite retention genetic algorithm. Finally, the proposed control method is simulated on the platform of Gazebo; compared with the traditional PD control method, the results show that the proposed control algorithm has high robustness, and the rationality of the coordinated trajectory control method is verified by the double-arm handling experiment.


Author(s):  
Miguel Aguiar ◽  
Joao Borges de Sousa ◽  
Joao Miguel Dias ◽  
Jorge Estrela da Silva ◽  
Renato Mendes ◽  
...  

2015 ◽  
Vol 25 (1) ◽  
pp. 159-174 ◽  
Author(s):  
Zhaohui Cen ◽  
Hassan Noura ◽  
Younes Al Younes

Abstract A systematic fault tolerant control (FTC) scheme based on fault estimation for a quadrotor actuator, which integrates normal control, active and passive FTC and fault parking is proposed in this paper. Firstly, an adaptive Thau observer (ATO) is presented to estimate the quadrotor rotor fault magnitudes, and then faults with different magnitudes and time-varying natures are rated into corresponding fault severity levels based on the pre-defined fault-tolerant boundaries. Secondly, a systematic FTC strategy which can coordinate various FTC methods is designed to compensate for failures depending on the fault types and severity levels. Unlike former stand-alone passive FTC or active FTC, our proposed FTC scheme can compensate for faults in a way of condition-based maintenance (CBM), and especially consider the fatal failures that traditional FTC techniques cannot accommodate to avoid the crashing of UAVs. Finally, various simulations are carried out to show the performance and effectiveness of the proposed method.


2020 ◽  
Vol 68 ◽  
pp. 4824-4838 ◽  
Author(s):  
Mohan Krishna Nutalapati ◽  
Amrit Singh Bedi ◽  
Ketan Rajawat ◽  
Marceau Coupechoux

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