Optimal obstacle avoidance via distributed consensus algorithms with communication delay

A consensus problem of multi-agent system subject to the communication delay with fixed and switching topologies as well as optimal obstacle avoidance is investigated. An innovative non-quadratic obstacle avoidance cost function is designed from an inverse optimal control perspective and a novel dynamic potential field whose vectors are rotating around the obstacle is introduced to avoid obstacles. The asymptotic stability condition of dynamical networks based on the Lyapunov-Krasovskii function is obtained via a linear matrix inequality (LMI) formulation. Finally, numerical examples are presented to show the effectiveness of the proposed theoretical results. © 2016 Beijing Institute of Aerospace Information.

Adaptive event-triggered distributed optimal guidance design via adaptive dynamic programming

In this paper,the multi-missile cooperative guidance system is formulated as a general nonlinear multi-agent system.To save the limited communication resources,an adaptive eventtriggered optimal guidance law is proposed by designing a synchronization-error-driven triggering condition,which brings together the consensus control with Adaptive Dynamic Programming(ADP)technique.Then,the developed event-triggered distributed control law can be employed by finding an approximate solution of event-triggered coupled Hamilton-Jacobi-Bellman(HJB)equation.To address this issue,the critic network architecture is constructed,in which an adaptive weight updating law is designed for estimating the cooperative optimal cost function online.Therefore,the event-triggered closed-loop system is decomposed into two subsystems:the system with flow dynamics and the system with jump dynamics.By using Lyapunov method,the stability of this closed-loop system is guaranteed and all signals are ensured to be Uniformly Ultimately Bounded(UUB).Furthermore,the Zeno behavior is avoided.Simulation results are finally provided to demonstrate the effectiveness of the proposed method.

Mutation of DELAYED GREENING1 impairs chloroplast RNA editing at elevated ambient temperature in Arabidopsis

Chloroplasts are important for plant growth and development.RNA editing in chloroplast converts cytidines(Cs)to uridine s(Us)at specific transcript positions and provides a correction mechanism to restore conserved codons or creates start or stop codons.However,the underlined molecular mechanism is not yet fully unders tood.In the present study,we identi fied a thermo-sensi tive mutantin leaf color 1(tst1)and found that TSL1 is allelic to DELAYED GREENING 1(DG1).The mis sense mutation of DG1 in tsl1 mutant confers a high temperature sensitivity and impaired chloroplast development at an elevated ambient temperature in Arabidopsis.Subsequent analysis showed that chloroplast RNA editing at seve ral sites including accD-2568,ndhD-2,and petL-5 is impaired in tsl1 mutant plants grown at an elevated temperature.DG1 interacts with MORF2 and other proteins such as DYW1 and DYW2 involved in chloroplast RNA editing.In vitro RNA electrophoretic mobility shift assay demonstrated that DG1 binds to RNA targets such as accD,ndhD,and petL.Thus,our results revealed that DG1 is important for maintaining chloroplast mRNA editing in Arabidopsis.