Scheduling dynamic loop

Amical uses a dynamic loop scheduling algorithm [13, 12]. This algorithm is adapted to control-flow-dominated designs written in Vhdl, and is a development of the path-based approach proposed by Camposano [2]. Essentially, the scheduler reads in a Vhdl description and produces a behavioral FSM in the form of a transition table. Each transition (macro-cycle) corresponds to the execution of a control step under a given condition. A macro-cycle may need several basic cycles (clock cycles) for its execution. The top left window in figure 4 shows the transition table composed of two states and five transitions. 

Suppose that the process is well known and that an adequate mathematical model for it is available. If there is an auxiliary process variable which correlates well with the changes in process dynamics, we can relate ahead of time the best values of the controller parameters to the value of the auxiliary process variable. Consequently, by measuring the value of the auxiliary variable we can schedule or program the adaptation of the controller parameters. Figure 22.1 shows the block diagram of a programmed adaptive control system. We notice that it is composed of two loops. The inner loop is an ordinary feedback control loop. The outer loop includes the parameter adjustment (adaptation)... 

Saturation of controllers, 247, 257, 637 Scheduling computer control, 33 Secondary loop, cascade control, 395, 397, 398-99, 400-2 Secondary measurements, 16, 16-18 Second-order system, 186-87 Bode diagrams, 328-30 with dead time, 215, 216 discrete-time model, 585-86 dynamic characteristics, 187-93 experimental parameter identification, 233,668... 

VI Single-loop nonlinear extensions of PID controllers with added compensation for difficult dynamics (e.g.. Smith predictors with gain scheduling). Alternatively, nonlinear model-based control strategies like GMC or Nonlinear Model Predictive Control (NMPC) [15] ... 

Recently, the trend in systems integration has been towards the use of automatic control in its broadest sense (including dynamic control, scheduling and closure of information loops) to integrate all 2ispects of the plant operations including closing the information loops within the plant. 

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