US Patent 7775297 Multiple input scaling autodriller

A wellbore drilling system is disclosed herein, in which the system includes a weight on bit controller configured to generate a normalized weight on bit output, a drilling torque controller configured to generate a normalized toque on bit output, and a differential pressure controller configured to generate a normalized differential pressure output. The system further includes a rate of penetration controller that is configured to multiply a rate of penetration setpoint with the normalized weight on bit output, the normalized torque on pit output, and the normalized differential pressure output to generate a rate of penetration output.