Realization and validation of Delay Tolerant Behavior Control based Adaptive Bandwidth Allocation for networked control system

In network based path tracking control of systems with multiple unmanned ground vehicles (UGVs), performance can be affected by network constraints including time-varying network delays and bandwidth limitation. Different static as well as dynamic bandwidth management strategies like Larger Error First (LEF), Rate Monotonic (RM), Behavior Control (BC) Based Allocation etc. have been proposed in the past to allocate bandwidth. However, these existing methods are not robust to network delay which is an important constraint in a Network Control System (NCS). The Delay Tolerant Behavior Control (DTBC) based Adaptive Bandwidth Allocation is one of the bandwidth allocation techniques that is robust to network delays. In this paper, DTBC algorithm has been validated and compared to the performance of existing algorithms in an intelligent space environment. IEEE 802.15.4 standard wireless protocol was used for communication between the unmanned ground vehicles (UGVs) and the Supervisory Controller. A T-test was conducted and we found that at network delays of more than 200ms we can say with 99% confidence that DTBC's performance is better than the existing algorithms. Furthermore, using the slope of the linear fit calculated for each algorithm's performance at different network delays, the performance of DTBC was found to be at least 25% to at most 57% better than the existing algorithms.