Improved control of distributed parameter systems using wireless sensor and actuator networks:An observer-based method

In this paper,the control problem of distributed parameter systems is investigated by using wireless sensor and actuator networks with the observer-based method.Firstly,a centralized observer which makes use of the measurement information provided by the fixed sensors is designed to estimate the distributed parameter systems.The mobile agents,each of which is affixed with a controller and an actuator,can provide the observer-based control for the target systems.By using Lyapunov stability arguments,the stability for the estimation error system and distributed parameter control system is proved,meanwhile a guidance scheme for each mobile actuator is provided to improve the control performance.A numerical example is finally used to demonstrate the effectiveness and the advantages of the proposed approaches.

A bioinspired,self-powered,flytrap-based sensor and actuator enabled by voltage triggered hydrogel electrodes

Because of its adaptive interfacial property,soft sensors/actuators can be used to perform more delicate tasks than their rigid counterparts.However,plant epidermis with a waxy cuticle layer challenges stable and high-fidelity non-invasive electrophysiology since the conventional electrodes are invasive,easily detached from plants,and require complicated setup procedures.Here,we report a bioinspired sensor and actuator created by using a conformable electrode interface as an electrical modulation unit on a Venus flytrap.Our conformable electrode,by employing an adhesive hydrogel layer,can achieve the merits of low impedance,stretchable,biocompatible,reusable,and transparent enough for normal chlorophyll activity to occur.Owing to the high sensitivity of a flytrap to a triggering mechanical stimulation,a plant sensor matrix based on flytraps has been demonstrated by capturing the stimulated action potential(AP)signals from upper epidermis,which can orient honeybee colonies by their touch during collecting nectar.Moreover,via frequency-dependent AP modulation,an autonomous on-demand actuation on a flytrap is realized.The flytrap actuator can be controlled to responsively grasp tiny objects by the modulated signals triggered by a triboelectric nanogenerator(TENG).This work paves a way of developing autonomous plant-based sensors and actuators toward smart agriculture and intelligent robots.

Node coordination mechanism based on distributed estimation and control in wireless sensor and actuator networks

Wireless sensor and actuator networks （WSANs） have a wide range of applications. To perform effective sensing and acting tasks, multiple coordination mechanisms among the nodes are required. As attempt in this direction, this paper describes collaborative estimation and control algorithms design for WSANs. First, a sensor-actuator coordination model is proposed based on distributed Kalman filter in federated configuration. This method provides the capability of fault tolerance and multi-source information fusion. On this basis, an actuator-actuator coordination model based on even-driven task allocation is introduced. Actuators utilize fused sensory information to adjust their action that incur the minimum energy cost to the system subject to the constraints that user＇s preferences regarding the states of the system are approximately satisfied. Finally, according to system requirements, a distributed algorithm is proposed to solve the task allocation problem. Simulations demonstrate the effectiveness of our proposed methods.