Network-based Software-in-the-loop Simulation for Real-Time Control System

This paper suggests a real-time implementation method for software-in-the-loop (SIL) simulation for control systems. The implementation is composed of a PC for the controllers, a PC for the plant, a general-purpose computer-aided control system design (CACSD)package, and an Ethernet network. The Ethernet network is investigated in terms of control issues such as sampling interval, network-induced time delay, use with multiple I/O points and data synchronization. A performance evaluation of software-in-the-loop simulation is carried out subject to a computation delay and a sampling interval. To reduce the effects of the time delay, particularly for fast plants, a time-scaling method is introduced for slow and fast motions. It is demonstrated that this real-time software-in-the-loop simulation will be very useful.