Modeling and compound control of disk brake automatic drilling system
This paper modeled the disk brake automatic drilling system for the first time and pointed out its characteristics of high-order and time-varying, what's more, it is very sensitive to disturbance. A claasic linear time-invariant controller has insufficiently addressed deep and deviated directional drilling process from the control standpoint. herein, compound control strategies with computer including cascade control and feed-forward control are introduced to eliminate disturbances which include the friction between drilling tools and borehole wall, the resonance of rope and drill pipes, and the vibrancy caused by downhole motors. The reliability and practicability of this automatic driller are increased by the adoption of Programmable Controller (PC). The system undergoes field test. The field experiments shown that the computer control methods above can effectively suppress interference during the deviated deep hole drilling operation, achieving a satisfied and reliable control performance. In addition, the study and control methods about this drilling system have universal significance to the application of other automatic drilling systems.