General steps for connecting a motion control card to a servo motor

1. Initialization parameters

Initialize parameters before wiring.

On the control card: select the control mode; Reset PID parameters; Enable the default enable signal to turn off when the control card is powered on; Save this state to ensure it is in when the control card is powered up again.

On the servo motor: set the control mode; Set up enabling external control; Gear ratio of encoder signal output; Set the proportional relationship between control signal and motor speed. Generally speaking, it is recommended to make the maximum design speed of servo operation correspond to the control voltage of 9V. For example, panasonic sets the speed corresponding to 1V voltage, and the factory value is 500. If you only want the motor to work under 1000 RPM, then set this parameter to 111.

2, connection

Disconnect the control card and connect the signal line between the control card and the servo. The following lines must be connected: analog output line of control card, enabling signal line, encoder signal line of servo output. The motor and control card (and PC) are powered up after checking the wiring is correct. At this point, the motor should not move and can be easily rotated by external forces. If not, check the Settings and wiring of enabling signals. Turn the motor with external force, check whether the control card can correctly detect the change of the motor position, otherwise check the wiring and setting of the encoder signal

3. Try the direction

For a closed-loop control system, if the feedback signals are not directed in the right direction, the consequences can be disastrous. Turn on the enable signal of the servo through the control card. This is a servo that should rotate at a lower speed, known as "zero drift." There are instructions or parameters to suppress zero drift on the control card. Use this command or parameter to see if the speed and direction of the motor can be controlled by this command (parameter). If not, check the analog wiring and control mode parameter Settings. Confirm to give a positive number, motor forward rotation, encoder count increase; Given a negative number, the motor turns around and the encoder count decreases. Do not use this method if the motor is loaded and has limited travel. Do not test too high voltage, recommended below 1V. If the direction is not consistent, you can modify the parameters on the control card or motor to make it consistent.

4. Suppress zero drift

In the closed-loop control process, the existence of zero drift will have some influence on the control effect, and it is better to suppress it. Use the control card or servo to suppress zero drift parameters, carefully adjust the motor speed to zero. Because of the randomness of the zero drift itself, it is not necessary to require the motor speed to be absolutely zero.

5. Establish closed-loop control

Once again, release the servo enabling signal through the control card, and input a small proportional gain on the control card. As for the size of the small gain, it can only be felt. If you are really worried, input the minimum value that the control card can allow. Turn on the enable signal of the control card and the servo. At this point, the motor should be able to follow the motion command to roughly make the action.

6. Adjust the closed-loop parameters

Fine-tuning the control parameters to ensure that the motor moves in accordance with the instructions of the control card is a must, and this part of work is more experience.