1. Initialize parameters.

Before wiring, initialize the parameters. On the control card: select the control mode; clear the PID parameters; turn off the energy signal when the control card is powered on by default; save this state to ensure that the control card is powered on again.

Servo motor: set the control mode; set the external control; the gear ratio of the encoder signal output; set the proportional relationship between the control signal and the motor speed. In general, it is recommended that the maximum design speed in servo operation corresponds to a control voltage of 9V.

2. Wiring

Cut off 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 the control card. make the signal line. Servo output encoder signal line. The servo motor and control card (and PC) are powered on after checking the wiring is correct. At this point, the motor should not move and can easily rotate with external force. If not, check the setting and wiring of the enable signal. Rotate 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 closed-loop control systems, if the feedback signal is not in the correct direction, the consequences are sure to be catastrophic. Turn on the enable signal of the servo through the control card. The servo should rotate at a lower speed, which is the legendary zero drift. Generally, 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 it cannot be controlled, check the analog wiring and parameter settings of the control mode. Confirm that if a positive number is given, the motor rotates forward, and the encoder count increases; if a negative number is given, the motor reverses, and the encoder count decreases. Do not do this if the motor is loaded and has limited travel. Do not give too much voltage for testing, it is recommended to be lower than 1V. If the directions are inconsistent, you can modify the parameters on the control card or motor to make them consistent.

4. Suppress zero drift.

In the closed-loop control process, the existence of zero drift will have a certain impact on the control effect, which needs to be suppressed. Use the control card or servo to suppress the zero float parameter and adjust carefully so that the motor speed is close to zero. Because the zero drift itself has a certain randomness, it is not necessary for the motor speed to be absolutely zero.

5. Establish closed-loop control.

Release the servo signal through the control card again, and input a smaller proportional gain on the control card. As for how small it is, it depends on the feel. If you are really worried, enter the smallest z value allowed by the control card. Turn on the enable signal of the control card and servo. At this time, the motor should be able to move roughly according to the motion command.

6. Adjust the closed-loop parameters.

It is necessary to adjust the control parameters in detail to ensure that the motor moves according to the instructions of the control card. This part of the work is more experience and can only be omitted here.