A comparison of proportional and model-based control tchniques for nuclear reactors

A comparison is given of proportional and model-based control as applied to spacecraft nuclear reactors. It is argued that proportional control is adequate for maintaining system parameters at desired steady-state values. However, proportional techniques are not suited for the trajectory control because they only provide positional information. This is inadequate because the proper solution of a tracking problem requires that both the speed and the direction of the actuator be specified. Model-based techniques can accomplish this. Also, they provide allowance for the non-linear and time-delayed aspects of the process. These features are achieved by incorporating knowledge of the system dynamics in the controller design. Such an approach is of particular importance in the control of safety-constrained systems. Examples drawn from closed-loop, digital control experiments conducted on the MIT Research Reactor are shown to support the above arguments