| Control systems wherein a network is used as a communication channel totransfer information among components are called networked control systems(NCSs). The use of networks in control systems enables resource sharing and mutualmaneuverability among nodes;brings simplicity in cabling;and also, makes systemdesign modular and flexible. However, its insertion makes the analysis and design ofcontrol systems more challenging. Because, during networks transmissionsinevitably exists delay, signal instability, packet loss etc, the direct use of traditionalcontrol theories in network control system design will have negative impact on theperformance of the system, even leading to instability. This dissertation analyzes theinfluence of network transmission on the performance of control systems, andresearch on control strategies considering network effects. In this work, thefollowing results are obtained:1. Based on the analysis of a networked control system, proposed controlstrategies to overcome the influence of network transmission delay for thecase when the controller and actuator are embedded into one node;thenderived necessary and sufficient conditions under which such system isstable. Considering the case when the delay is less than a sampling period,the plant model, the time stamped data packet, and the current plant statewere used to calculate the state value when it reaches the actuator and thenthe relevant control signal is provided to compensate for the influence ofnetwork transmission delay. For the long time delay, used the plant modeland the received plant state to estimate the current plant state value eachperiod h, and then used the estimator output to calculate the control signal.Furthermore, when a new plant state is received at the controller, it is usedto correct the estimated state value.2. Proposed the use of the CEDP (Compensation and Estimation for Delay andPacket dropout) method to overcome the problem of transmission delay andpacket dropout. For this method the plant state model approximation wasbuilt up at the controller unit, and the time stamped single data packet usedfor data transmission. The compensator was used to overcome the influenceof network transmission delay. In case of data packet loss, the estimator wasused to estimate the plant state. This was done so as to reduce, or eveneliminate the influence of network transmission on the control signalcalculation.3. The system obtained using the CEDP method in the networked controlsystem (CEDP-NCS) was modeled as an asynchronous dynamical system(ADS) with rate constraint on two events. Then a time varying bilinearmatrices' inequalities (BMIs) for the CEDP-NCS system's exponentialstability was derived.4. To obtain the maximum value of the networked control system decay rate,proposed a method to solve the time varying BMIs problem, created twoMatlab functions bound_logαi and decay_rate_ncs to implement the BMIscalculation. Then a procedure of finding a feasible set for the BMIs wasobtained.
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