| 摘要 |
PURPOSE:To contrive to change the pressure output of a proportional control valve along a prescribed target pattern, by controlling the proportional control valve with an analog value obtained by adding a correcting analog value to the steady-state analog value of the proportional control valve. CONSTITUTION:A computer 10 calculates a target pressure Pi+1 at a time ti+1 a unit time after a certain time ti based on a preliminarily calculated target pattern. A steady-state analog value V0 of a valve 4 corresponding to the pressure Pi+1 is calculated. Meanwhile, a pressure Ps in a surge tank 5 at the time ti is detected by a pressure sensor 14 and is inputted to the computer 10, and simultaneously, a pressure Pm of a holding furnace 7 is detected by a pressure sensor 11 and is inputted to the computer 10. A pressure difference DELTAPi between pressures Ps and Pm is calculated. A pressure difference DELTAP2 between pressures Pi+1 and Pm is calculated. A gain G corresponding to the difference DELTAPi is multiplied to calculate a correcting analog value Vd. Values V0 and Vd are added to calculate a command analog value V. The value V is inputted to the valve 4.
|
