| 摘要 |
<p>A valve (10) positioner system (12) that includes one or more unique control methods and devices, including several routines (80) to facilitate the continuous maintenance, calibration and adjsutment requirements of the valve. The positioner system may utilize pressure and position feedback signals (42) to monitor the valve. The positioner system may utilize an external controller (18) for various diagnostic and other routines (80). The positioner system (12) can provide automatic positioning and can operate in a manual operating mode or an automatic operating mode. The positioner system (12) can diagnose the valve while the valve process is running or during a maintenance operation. The positioner system (12) can provide nonlinear control of the valve position. The positioner system (12) can self-tune and self-characterize the valve to assure uniform position control. The positioner system (12) can provide valve control through pressure feedback (40) when a position feedback (42) fails or other diagnosed problems. The positioner system (12) can provide constraints to prevent slope reversal or slope changes in the valve characterization that would produce undesirable valve gain.</p> |
