Hi DoF Pros,

I have been using FT300 for a while, I am posting here to confirm what I got is reasonable. 

Setup:  UR5/CB3/Polyscope 3.3.4/Robotiq 85mm gripper/FT300     FT300 purchased in July, accuracy would be 1N according to Robotiq,  URCap Version 1.0.1

1. The frequency I got is typically 62.5HZ, sometimes even lower than than (20HZ), please see attached picture.  I tried different USB ports, never could get 125HZ, is this normal?


2. After calibration, and all procedures suggested by the manual, I still get a 3-5N drift on Fx, Fy or Fz even the sensor is not touching anything. And this value jumps a lot even in static.   I attach a picture of sensor reading when the robot is at rest, not touching anything.


Is this the normal signal I would expect from FT300?

Thank you so much !

@jianlan_

Since july, we have changed our electronic board inside the sensor to have a better signal.  At that time the standard deviation of the signal noise was 1.2 Newton in Fx, Fy.  With what I see, everything seems normal.  Don't forget to use the command rq_set_zero() before taking measurements.

Regarding the frequency, I got the same rate as you if the thread takes too much time.  UR can confirm that but what I understand is that thread are started with a clock at a fixed rate of 125 Hz.  If the thread is not ready, it will be started at the next tick of this 125Hz clock which can give you this 62.5Hz.  

For your information, the new electronic board now give us a standard deviation of the signal noise as low as 0.1 Newton in Fx, Fy and Fz.

@louis_bergeron

Thanks for the reply. Just to confirm,  my FT300 SN number is 2017 S/N F-30776, is this the new model with 0.1 std or old 1.2N std one? 

Also, I am using CB3.0 + PolyScope3.3.4+ URCap 1.0.1.  From what I learned from the forum, I can't upgrade to newer URCap  because of the compatible issues.  When I tried to use rq_set_zero(), it pops up a window 'rq_set_zero() is not defined', is this something to do with URCap version?   Is upgrading to CB3.1 the only solution?

May I know how rq_set_zero() works?  Does it zero the current sensor value, and set as a zero reference point?

Thanks!

@jianlan_

For your information, our sensor have the new electronic board since October, you then have the previous one.  To get the rq_set_zero() function on the urcap version 1.0.1, you must start your program with the template_sensor.urp.  This template includes a script file "accessor_capt.script" where the function is defined.  The template_sensor.urp will also give you access to the force and torques values in your program.  The rq_set_sero() or rq_zero_sensor() since the latest urcap function will effectively zero the current sensor value.