A co-design solution for wireless feedback control

This paper demonstrates how the principles of codesign, the merging of communication technology with control theory, can simultaneously improve both control and communication performance within an IEEE 802.11b wireless networked control system (WNCS). Data rate scaling is first described, which is a special property within 802.11 wireless networks that improves the frame error ratio (FER) of the communication channel under poor channel conditions. This is followed by a description of sample rate adaptation, a control technique that adapts the sampling interval in response to time-varying network parameters. Although both schemes are effective individually, significant improvement in performance was seen when both were used together, thereby highlighting the benefits of co-design. Supportive results are presented from a simulated cart-mounted inverted pendulum system.