Implementation of an Internet-based remote controller with guaranteed exponential stabilization

Wenjuan Jiang (1) , Jean-Pierre Richard (2, 3) , Armand Toguyeni (1)

1 LAGIS - Laboratoire d'Automatique, Génie Informatique et Signal
2 ALIEN - Algebra for Digital Identification and Estimation
3 SyNeR - Systèmes Non Linéaires et à Retards

An Internet-based remote control system is designed and implemented. The communication is based on the Master-Slave structure. The Master PC communicates with the Slave from about 40km away by UDP protocol. In order to guarantee the Master and Slave clocks to be synchronized, the NTP (Network Time Protocol) is used in both sides. The packets are sent together with time-stamps. The controller design (Master) relies on a remote observer that achieves a state prediction of the application (Slave), despite the variable communication delays. The Slave comprises a PC and a robot Miabot of Merlin company. Internet-based remote systems are subject to variable time delays (including communication and data-sampling delays). We have continuously tested the RTT (round-triptime) between the two PCs in the day-time and night-time by the protocol ICMP (Internet Control Message). From these tests, an evaluation of the maximal time delay is obtained. The structure allows one to guarantee an exponential stabilization performance, which is proven via a Lyapunov-Krassovski functional technique and involves the estimated delay upperbound. This means that the guaranteed decay rate is computed (via some LMI optimization) in relation to some maximal value of the communication delays. Of course, for greater delay values, the performance cannot be guaranteed anymore and an alternative solution has to be considered. In our system, we give a command for the robot to stop until the communication comes back to a sufficient quality.

Domaines: Automatique; Réseaux et télécommunications [cs.NI]; Robotique [cs.RO]; Systèmes dynamiques [math.DS]

Wenjuan Jiang, Jean-Pierre Richard, Armand Toguyeni. Implementation of an Internet-based remote controller with guaranteed exponential stabilization. ICA'08 - 7th IEEE World Congress on Intelligent Control and Automation, Jun 2008, Chongqing, China. pp.4063 - 4068, ⟨10.1109/WCICA.2008.4594512⟩. ⟨inria-00266452⟩