Managed Pressure Control System with Variable Built-in Accuracy

A drilling choke is controlled in a controlled pressure system. Pressure is monitored in the controlled pressure system, and position of the drilling choke is monitored. An adjustment to the position of the drilling choke is determined based on the monitored pressure to control the drilling pressures. An actuation is produced of an actuator operably coupled to the drilling choke to implement the determined adjustment. Rather than directly transferring, the actuation of the actuator is transferred with a transfer mechanism to motion of the drilling in a non-linear relationship relative to the position of the drilling choke. Generally, motion of the choke's internal trim (e.g., gate, ball, flapper, disc, etc.) is made quicker when near a fully opened position and is made slower when near a fully closed position. This reduces the need for strict precision for the motion. In the end, the monitored pressure is altered in response to the implemented adjustment of the drilling choke.