High accuracy weight / force sensor for the robot flange

General Application Help: How do I?
1

Hello, we have a use-case where we would like the robot to monitor the weight of an object it is gripping.

Imagine the robot holding a Bucket and fluids of different viscosities flowing into it. We want to cut off the fluid flow after a certain weight is reached. However, we need an accuracy that is higher than the sensing capabilities of the robot.

Ideally we want to weigh to an accuracy of ±2g (0.07 oz).
Is there a Flange-mounted force/torque sensor that is this accurate?
The highest accuracy I could find is ± 10g (Robotiq FT-300, Nordbo NRS-6050-D80 (PDF datasheets))

Are there other ways of achieving higher accuracy with these sensors (i.e. extending the moment-arm).
For several reasons I want to avoid measuring the fluid flow itself or using an external measuring station. Attaching the weight sensor directly to the robot would make the application as flexible as possible.

Any Ideas would be highly appreciated.
Thank you in advance.

2

Hey,

Could you add some sort of load cell/weight sensor to the work cell. That way you could take the input from the weight sensor into the cobot to make decisions from that. You could maybe add it to a custom tool or modify an already existing tool.

If you didnt want to have the sensor on the tool, could you make a jig that sits under the fluid flow with the sensor on it. That way the cobot could place the vessel onto the load cell and the cobot can stop the flow when the weight is reached.

It could be very likely that i am not understanding the question properly though, so if this isnt approprite im sure there will be someone else on here with better ideas.