Servo Motor Position Motor Not Accurate

Hello Friends,

I am facing problem on my servo position.

I have pick n place machine , where my pick n place position are servo motor position controlled.I am facing problem is after few continuous cycle the position is not the same.
For example my calibration position is 85mm but after continous cycle position is out to 95 mm.I have crossed check my PLC code there is no calculation mistake.

Once i have origin my servo position starts from 85mm but after few cycle it starts to drift again.

Is there a possiblity of Noise on Servo pulse train cable ?
Cable are twisted pair cables for servo to move ccw and cw direction.

Can someone help me how to reduce noise or what could be cause of noise.?

Appreciate some direction

I would look at what the feedback signal is when it starts to go out of specification. It could be temperature related...

Possibility: loose or worn position sensor in the servo.

Do you have a spare servo to replace the part and test it again ?

DEAR...

If you have a spare servo to replace.. if yes, then you can replace the part and test it ..again..

THANKX...

Hi there Vik,
Is it your intention to be sarcastic ? Most people here are trying to be helpful.

Mr Rohit ,

Temperature on monitoring showed it is very stable and machine is in clean room enviornment.

The command pulse and received pulse on the servo drivor has differs....Looks like servo driver receiving pulse Cable (CCW/CW) has noise picking up from panel wiring.

I have added some ferrites and Isolated AC/DC wiring from eachother.

I will try to monitor it now...

Thank you,
Ankim

DEAR I am trying to find out root cause.....before i suspect its a servo driver or servo motor fault.

Mr Frank,

My servo sequence is Position based and not sensor based.

Ankim

Servos have position sensors (encoders) built in. What kind of actuator are you using? If the encoder of the servo is not damaged or loose, and if the actuator is a belt, is the belt slipping?

Hi there Ankim.

Though it has been 10 months, I would like to share my ideas on this problem.

I think you are having a problem with offset. Position controlled feedback systems are very vulnerable to this. I suggest using a PID controller. You just have to add a few resistors and capacitors here and there. The schem. can easily be googled.

If this doesn't work, then the problem may indeed lie in parts replacement.

Regards,
Justin

Hi Ankim Tandon ,

I think this is a mechanical problem your arm mover will have a spring loaded
system which will help the arm to reach the zero level point after every forward
movement , may be the spring fixing is loose or tension of the spring is gone or
wrong mech fixing. the servo motor is driven usually by transistors some times
one of the power transistor or its driver transistor may be weak replace it.

pl review my rating.

V.Sambath kumar

Dear.
I have also faced the same problem .Reason:1. Pulse train wiring interracted with ac power supply cables2. amplifier issue3. 99percent - noise from ac power suply in the panel Remedy : use noise filter between ac power supply.