| 摘要 |
A control technique is disclosed for use with intermittently provided process variable (p.v.) information, especially when provided via a wireless network. The technique employs a controller 601, e.g. a PID controller, and a modified Kalman filter 604. The Kalman filter includes a control signal input Uj, an interface 660 receiving p.v. measurement signals Zj, a process model 410, 412, 424 & 426 arranged to produce an initial p.v. estimate, and a correction unit 416, 418 & 622 arranged to produce a correction signal from a residual. During the execution cycle of the Kalman filter unit at which a new p.v. value is available, and during a predetermined number of cycles thereafter, a switching function 662 operates to provide a new value of the residual to the gain unit 622 to produce the correction signal. Alternatively, during execution cycles of the Kalman filter unit after the predetermined number of cycles after the cycle at which the p.v. is available, the switching operates to provide a stored value of the residual to the gain unit. |
