At last , it deduced a new improvement method from the theories , and make use of a new physical concept ? the independent of speed function for accuracy checking up the turns sub - position and the communication point so as to control sensorless brushless dc motor with the breadth regulating - speed scope from zero to high speed . based on the function , it will research the new control method 最后,从理论上推导了新的改进方法,并利用一个新的物理概念? ?与速度无关的位置函数g ( ) ,其能高精度检测出转子位置和换相点,以此来控制无刷直流电机,实现电机从零转速到高转速的宽速度范围调节,在此基础上研究了应用这种新的位置函数的控制策略。