| 摘要 |
PURPOSE:To attain the fast shift to the PID control and to reduce the overshoot of the controlled variable as well as the converging time to the target value, by measuring the gradient serving as the final data for decision of PID constant at a point near the target value. CONSTITUTION:A step response measuring part 8 outputs a prescribed manipulated variable y0 with operation of a start switch 15 and impresses the variable y0 to a controlled system 13 via an output control part 5. The controlled variable C and the target value (r) set at the time of the step response is supplied to the part 8. The gradients R and L which are internally measured are supplied to a PID (proportion, integration and differentiation) constant arithmetic part 7. The part 7 decides the optimum values of the proportion sensitivity Kp, the integration time Ti and the differentiation time Td serving as the PID constants and sends them to a main arithmetic part 6. The part 6 obtains the deviation (e) between the input (r) and C and at the same time supplies a manipulated variable (y) to the part using an operation expression corresponding to the PID constants and the deviation (e) for execution of the PID control. In such a way, the fast shift is attained to the PID control together with reduction of the overshoot of the controlled variable as well as the converging time to the target value.
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