| 摘要 |
PURPOSE:To linearize an execution flow rate characteristic of a control valve, by using a multiplied value of an output of a generator for generating an inverse function of flow rate gain against an output of a control meter of the control valve, and an output of a reference gain setting devie, as proportional gain of the control meter. CONSTITUTION:An output of a flow rate detector 1 is inputted to an input linearizing circuit 2, and a linearized output PV is inputted to a control meter 3. An output MV of the control meter 3 is inputted to a control valve characteristic compensating circuit 4, in which proportional gain for compensating a nonlinear characteristic of a control valve 5 is outputted to the control meter 3, and one round loop gain containing the control valve 5 is made constant. On the circuit 4, an inverse function generator 11 for generating an inverse function of flow rate gain against the control meter output MV, and a reference gain setting device 12 are provided, and outputs of the generator 11 and the setting device 12 are multiplied by a multiplier 13, and are applied as proportional gain to the control meter 3. In this way, the total gain containing the control meter 3 and the control valve 5 becomes constant against all the operation quantity MV, an execution flow rate characteristic of the control valve 5 is linearized, and the loop gain can be taken greatly, therefore, optimum control of the system can be executed. |
