In this paper, we present a theoretical analysis on stability and convergence of the cautious control, which has advantages over the traditional certainty equivalence adaptive control, since it takes the parameter est...In this paper, we present a theoretical analysis on stability and convergence of the cautious control, which has advantages over the traditional certainty equivalence adaptive control, since it takes the parameter estimation error into account in the design, and is also one-step-ahead optimal in the mean square sense under Gaussian assumptions.展开更多
This paper studies the leader-following attitude coordination problems of multiple spacecraft in the presence of inertia parameter uncertainties. To achieve attitude coordination in the situation that even the leader&...This paper studies the leader-following attitude coordination problems of multiple spacecraft in the presence of inertia parameter uncertainties. To achieve attitude coordination in the situation that even the leader's attitude is only applicable to a part of the following spacecraft, a nonlinear attitude observer is proposed to obtain an accurate estimation of the leader's attitude and angular velocity for all the followers. In addition, a distributed control scheme based on noncertainty equivalence principle is presented for multiple spacecraft' attitude synchronization. With a dynamic scaling, attitude consensus can be achieved asymptotically without any information of the bounds of the uncertain inertia parameters. Furthermore, once the estimations of inertia parameters reach their ideal values, the estimation process will stop and the ideal value of inertia parameter will be held. This is a special advantage of parameter estimation method based on non-certainty equivalence. Numerical simulations are presented to demonstrate that the proposed non-certainty equivalence-based method requires smaller control toque and converges faster compared with the certainty equivalence-based method.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.60221301 and 60334040)the Basic Research Funds of Beijing Institute of Technology.
文摘In this paper, we present a theoretical analysis on stability and convergence of the cautious control, which has advantages over the traditional certainty equivalence adaptive control, since it takes the parameter estimation error into account in the design, and is also one-step-ahead optimal in the mean square sense under Gaussian assumptions.
基金supported by the National Natural Science Foundation of China(Nos.11402200,11502203)
文摘This paper studies the leader-following attitude coordination problems of multiple spacecraft in the presence of inertia parameter uncertainties. To achieve attitude coordination in the situation that even the leader's attitude is only applicable to a part of the following spacecraft, a nonlinear attitude observer is proposed to obtain an accurate estimation of the leader's attitude and angular velocity for all the followers. In addition, a distributed control scheme based on noncertainty equivalence principle is presented for multiple spacecraft' attitude synchronization. With a dynamic scaling, attitude consensus can be achieved asymptotically without any information of the bounds of the uncertain inertia parameters. Furthermore, once the estimations of inertia parameters reach their ideal values, the estimation process will stop and the ideal value of inertia parameter will be held. This is a special advantage of parameter estimation method based on non-certainty equivalence. Numerical simulations are presented to demonstrate that the proposed non-certainty equivalence-based method requires smaller control toque and converges faster compared with the certainty equivalence-based method.
