Servo Motor Accurate Location Method
Servo mainly rely on pulse to locate,we can understood like this,the servo motor receives a pulse,it will rotate a pulse corresponding to the angle,in order to achieve displacement,because the servo motor itself has a pulse function,so the servo motor each time rotate an angle,will send a corresponding number of pulses, so that the servo motor receiving pulse formed a call,or called closed loop,this way,the control system will know how many pulses sent to the servo motor,but also received how many pulses,So that it can precisely control the motor rotation,and achieve accurate positioning,can reach 0.001mm.
DC servo motor is divided into brush and brushless motor.Brush motor low cost,simple structure,large starting torque, wide speed range,easy control,need to maintenance,but maintenance is not convenient (change carbon brush),resulting in electromagnetic interference,have environment requirements.So it can be used for cost-sensitive general industrial and civilian applications.Brushless motor small size,light weight,output torque large,fast response,high speed,inertia small,smooth rotation,torque stability.Control complex,easy to achieve intelligent,the electronic commutation way flexible,can be square wave commutation or sine wave commutation.Motor no need maintenance,high efficiency,low operating temperature,electromagnetic radiation small,long life,can be used for a variety of environments.
AC servo motor is brushless motor,divided into synchronous and asynchronous motor,the current motion control are generally used synchronous motor,its wide power range,can make large power.High inertia,the highest rotational speed is low,and with the power increases and quickly reduce.Then it is suitable for low-speed smooth operation application.
The internal rotor of the servo motor is permanent magnet,the servo drive controls the U / V / W three-phase electric field to form the electromagnetic field,the rotor rotates under the action of the magnetic field,and the motor encoder feedback signal to the driver,the driver based on the feedback value and the target value to compare,and adjust the rotor rotation angle.The accuracy of the servo motor depends on the accuracy of the encoder (number of lines).
AC servo motor and brushless DC servo motor functional difference:AC servo is better,because it is sine wave control,torque ripple small.The DC servo is a trapezoidal wave.But the DC servo is relatively simple and cheap.