Performance assessment and compensation for secure networked control systems

Network-control-systems (NCS) have been gaining popularity due to their high potential in widespread applications and becoming realizable due to the rapid advancements in embedded systems, wireless communication technologies. This paper addresses the issue of NCS information security as well its time-sensitive performance and their trade-off. A PI controller implemented on a network to control the speed of the DC motor is used to illustrate the performance assessment for secure networked control systems. Network security algorithms DES, 3DES, and AES are integrated with the application to secure the sensor as well as control data flow on the network. Standard 2^k factorial experiment design is used to study and estimate the effect of each security algorithm. A 1-D gain scheduler is then designed to compensate for the adverse effect due to security. Thorough experimental results, system factors including network security and system gain affecting the performance are evaluated, analyzed, and categorized.