Fuji servo motor structure, nature and control

In fact, the servo motor is strictly a motor system. A single motor cannot be called a servo motor. The system consisting of a motor and a sensor and a controller can achieve a relatively accurate position, speed or torque output. We call it It has a servo motor system.

And what are the "rudders" that we often hear from the model of the model airplane and the model of the boat? In fact, the steering gear is only a common name. It is a simple basic servo motor system. It is a modified type of servo system suitable for RC airplanes. It is low in price. It is also often found in small mechanical devices with less torque. The range of angles of activity is small and the control accuracy is limited.

The word servo comes from the Latin word "Servus", which means "slave", which means to perform actions according to commands. As we mentioned earlier, the biggest characteristic of servo motors is that they can be precisely controlled according to the speed, position, torque and so on. So how is this more precise control implemented?

Then we will introduce the three-loop control of the servo motor, and the ring is the negative feedback regulation system.

The innermost ring is a current loop directly inside the servo driver. The Hall effect sensor detects the drive current of each phase of the driver to the motor and performs PID adjustment. The current loop is mostly used to control the motor torque and responds fastest in torque mode.
The intermediate ring is a speed loop that controls the motor by detecting the signal output of the motor encoder.

The outermost ring is the position loop, which can be chosen between the drive and the motor encoder or between the external controller and the motor encoder or the final load depending on the actual situation.

The reason why it becomes a three-loop control is because they are connected to each other. The current loop quickly and accurately controls the motor based on the speed loop command. The speed loop quickly and accurately controls the motor based on the command speed of the position loop, making it unaffected by the load and quickly tracking changes in command speed. The position loop compares the detection signal with the given value and outputs the command speed of the speed loop so that the position of the actuator coincides with the command position.

The structure, nature and control of Fuji servo motor.
The above content was provided by A&S Servo Motor Co., Ltd.