The double close loops of speed and current control is introduced in the system and the PI control is implemented in the current and speed loop, the position of rotor pole is detected by hall element.
系统采用电流、速度双闭环控制，电流、速度的调节采用PI调节，转子磁极位置通过霍尔元件检测。
2
Process control is under the influence of all parts of loop, but the most direct and apparent part is the final element i. e. control valve.
过程控制中的各个环节对控制都有影响，而最终环节即调节阀对过程控制的影响最为直接和明显。
3
In the second case, a nonlinear element may be situated anywhere in a controlloop while the input of the element is known.