Abstract
This paper proposes a new control method “Presumtive Optimal Control”, which is useful for the system composed of a informationless ternary error sensor and the plant assumed having 2nd order transfer function. Ouptut of the ternary sensor is ‘-1’, ‘0’, or ‘+1’ according to signs of system error, where ‘0’ indicates that the error is within the permitted range. Such a sensor provides exact positional information only at the boundary of permitted range, while its output changes. So the system state is quite uncertain while the error is out of the range. But once the error goes out through the permitted range, we must try to bring the error back into the range and to settle there. Then some suppositions to the system state are needed for controlling it. The presumptive optimal control presumes the system state such that the error comes back into the permitted range next instant, then the sufficient information is given. With such a presumption it fixes its control input as optimal at that moment, and repeats such processes at each moment.
Simulation by digital computer shows that the presumptive optimal control has better performance than other conventional control methods.
