How to Use Servo Motor?
Servo motor is an independent electrical device, which can rotate each part of the machine with high efficiency and precision. The output shaft of this motor can be moved to a specific angle, position, and velocity that a normal motor does not have. Servo motor adopts conventional motor and its position feedback with the sensor. Before using the servo motor, you need to know how to use it to better play its role.
Power of the control card and connect the signal line between the control card and the servo. The analog output line of the control card enables the signal line and encoder signal line of the servo output, These wires have to be connected. Power on the motor and control card after the cables are correctly connected. At this point, the motor should not move and can be easily turned by external forces. If not, check the setup and wiring of the enable signal. Rotate the motor with external force and check whether the control card can correctly detect the change of motor position. Otherwise, check the wiring and settings of the encoder signal.
For a closed-loop control system, if the feedback signal is not in the right direction, the result is certainly disastrous. Turn on the servo enable signal through the control card. This is where the servo should rotate at a slower speed, which is known as "zero drift". There are general instructions or parameters on the control card to suppress zero drift. Use this command or parameter to see if speed and direction can be controlled by this command (parameter). If it cannot be controlled, check the analog cable connection and the parameter setting of the control mode. Confirm that a positive number is given, the motor is running, encoder count is increased; negative numbers are given, the motor rotates backward, and the encoder count decreases. Do not use this method if the motor is loaded and has limited travel. Do not test for excessive voltage, recommended below 1V. If the directions are inconsistent, modify the parameters on the control card to make them consistent.
Zero Drift Suppression:
In the closed-loop control process, the existence of zero drift will have a certain influence on the control effect, and it is better to restrain it. Use a control card or servo to suppress the parameters of zero drift, carefully adjust the speed of the motor to zero. Because zero drift itself also has certain randomness, so, do not require the motor speed is zero.
The servo motor itself has the function of sending pulses, so every rotation of an angle will send a corresponding number of pulses. This creates an echo, or closed-loop, with the pulse received by the servo motor. In this way, the system knows how many pulses are sent to the servo and how many are received back. Thus, it can control the rotation of the motor very accurately, to achieve accurate positioning, which can reach 0.001mm.
Problems Need to be Understood in the Use of Servo Motor:
- In the use of servo motor, there will often be excessive noise, the servo motor is driven load operation is not a smooth phenomenon. At this time, we need to check to determine whether the servo motor is the problem before making a decision. If you cannot determine the cause, you can consult professional technical personnel, let them test, check out the cause, tailor the medicine to different problems.
- On the problem of inertia matching, inertia has a certain impact on the stability, accuracy, and dynamic response of the servo system, so we must pay attention to whether the choice of inertia matching.
- Selection of servo motors. Before selecting and using, we need to know what type and power size we need.
Precautions in use:
- When mounting/removing the coupling component to the servo motor shaft end, do not hit the shaft end directly with a hammer. (Hammer directly hits the shaft end, the encoder at the other end of the servo motor shaft will be broken.)
- Try to align the shaft ends to their best. (Improper alignment may cause vibration or bearing failure.)
- Ensure that radial and axial loads applied to the servo motor shaft during installation and operation are controlled within the specified values for each model.
- Extremely careful should be taken when installing a rigid coupling, especially as excessive bending loads can cause damage or wear to shaft ends and bearings.
- It is best to use flexible couplings to keep the radial load below the allowable value, which is designed for high mechanical strength servo motors.
- Ensure that cables are not subjected to torques or vertical loads due to external bending forces or their weight, especially at cable exits or connections.
- If the servo motor is connected to a reduction gear, the servo motor should be lubricated to prevent the oil from the reduction gear from entering the servo motor.