Turning dc motor into servo with JRK 21v3

Support Motor controllers/drivers and motors
1

Hi,
I am building a fly-by-wire throttle system and need to control a servo on a throttle body. I have a throttle body with what i assumed was a servo attached, but i discovered it was only a DC motor. There are two potentiometers on the output shaft, and they feed back to the ECU, which I unfortunately don’t have. I assume the ECU then provides a closed loop feedback to the motor to essentially turn it into a servo. While i’m sure i could do this with the Arduino i’m using, I am worried about the settling time and efficiency of my control system. Since this is going to be controlling the fuel going into an engine, I would like something a little more professional. I would like to avoid mounting a servo to the system, right now the DC motor is packaged really well and it would be a pain to mount a servo.

Would the JRK 21v3 work for this? It says it can provide closed loop feedback for position control, so it sounds like it to me. Does anyone have any recommendations?

Thanks!

2

Why are there two potentiometers? Is at least one of them mounted in a way so that it can detect the position of the output shaft and be used as position feedback? If you’re unsure, you should power the potentiometer by supplying 0 V and 5 V to the correct two wires, and then measure the voltage on wiper (the other wire). If the voltage on the wiper stays within 0-5V, and is a monotonic function of the output shaft position, then this is what the jrk was designed for and it should work for you. You can use the jrk in Analog Feedback mode to do PID control of the output shaft position.

How do you want to send commands to your throttle system? The jrk supports serial, analog, and rc pulse inputs. If the Arduino is your master controller, serial would be the best.
–David