Multi-quad Rotors’ Consensus Formation Control Method For Target Tracking

With the development of unmanned equipment,quadrotor UAVs have been widely used in military and civil missions.Among them,the tracking task for the ground moving target is a significant branch of the most widely used quad rotor.Although researchers have studied the single quad rotor control extensively,the complexity of solving multiple nonlinear subsystems poses a severe challenge to the formation control of quad rotors.Meanwhile,considering that a cooperative task of multiple quad rotors needs to not only maintain a certain degree of autonomy but also meet a certain degree of coordination,the adoption of distributed control and ensuring consensus is also a difficulty in the cooperative control of multiple quad rotors.Therefore,the multi-quad rotors’ formation control method for ground moving target tracking has high research value in both military and civil aspects.This paper has studied the multi-quad rotors’ formation control method for ground moving target tracking from the two aspects of ground target state estimation by multiple quad rotors and multi-quad rotors’ consensus formation tracking,and contributes on the following aspects:Firstly,in the study of ground target state estimation by multiple quad rotors,considering the prior information of the target in practical application is often not available in advance,and when the target is subjected to random maneuver,leading to a large tracking error,this paper studied a parameter-adaptive maneuvering target tracking algorithm.The output error results are fed back to the maneuvering frequency parameters in the current statistical model so that the parameters can be updated adaptively.Both theoretical analysis and simulation results illustrate that the algorithm improves the accuracy of trajectory estimation for maneuvering targets when prior knowledge is insufficient.Futhermore,considering the control restriction of under-actuation and coupling characteristic of quadrotor dynamics,an adaptive control algorithm(ACNTSMA)based on continuous non-singular terminal sliding mode is proposed in this paper.The adaptive control algorithm is mainly improved from two aspects of quad rotor control system: firstly,the sliding mode surface compensation algorithm is proposed to reduce the coupling relationship between variables in the position subsystem and improve the accuracy and response speed of the algorithm.Secondly,an adaptive algorithm is proposed to feed the error back to the sliding mode parameters,which improves the response and convergence speed of the algorithm.And,with the combination of consensus theory,a distributed uniform consensus formation control protocol under full-connected condition is proposed.The distributed control rate of the scheme is also provided.Although the proposed algorithm is based on ACNTSMA,the stability analyses show that the consensus protocol can be applied to all sliding mode algorithms with finite time stability and applicable to second-order integral models.The distributed consensus control rate also has a faster response speed.Finally,considering that the communication topologies are always time-varying to practical applications,this paper studies a time-varying topological tracking scheme based on weighted parameter updating.First of all,on the basis of the proposed consensus protocol in the full-connected case,this paper has improved it,by broadening the applicable scope of the protocol,and made it applicable in the non-fully connected case.The consensus control factor in the protocol is analyzed,and a new calculation formula is given.The stability analysis and simulation results show that the algorithm is able to keep the consensus of formation tracking in finite time under the time-varying topology,and also has faster response speed and higher accuracy.