Observability and delay compensation of integrated communication and control systems.

摘要

Integrated Communication and Control Systems (ICCS) are essential for automation, fault accommodation, and real-time and non-real-time decision making in complex and distributed dynamical processes like computer integrated manufacturing and advanced aircraft and spacecraft. Asynchronous time-division-multiplexed networks are suitable for flexible and reliable communications between spatially distributed components of ICCS. In these integrated systems, a control loop is closed via the common communication channel which multiplexes digital data from the sensor to the controller and from the controller to the actuator along with those from other control loops and decision-making and plant management functions. The network introduces distributed randomly varying delays in the control loop, which degrade the system dynamic performance and are a source of potential instability.;The dissertation presents the theory and conceptual design for a predictor/observer algorithm that compensates for network-induced delays and generates a finite-dimensional, linear, time-invariant model of the closed loop control system. The definition of observability is extended to account for recurrent loss of sensor data (due to noise in the network) and thus ensure effectiveness of the observer.;The efficacy of the delay compensator has been demonstrated by on-line speed control of a servomotor at a network testbed. The experimental results show that the compensator significantly improves the servomotor's dynamic performance and stability even though the plant is, in fact, nonlinear, its model is inexact, and the predictor/observer algorithm is formulated on the basis of linear system theoretic principles. The delay compensator has also been verified, by simulation, for longitudinal motion control of an advanced tactical aircraft where the ICCS is served by the SAE linear token passing bus protocol.