Linear Gripper

By Dan Chen, May 5, 2015

Linear Gripper

I used a compact linear actuator by Firgelli, it is both fast and strong. It is much lighter than my previous design, which requires 2 servos.

The original gripper features a Compact Capacitive Pressure sensor. Due to the high noise level and large package, I decided togo back and use Force-Sensing Resistors FSR. It is not ideal, but it’s a good trade off. I just need to mount the FSR carefully (No heat, glue & no bending)

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Object Sensing

I mounted 2 distances sensor by Sharp, the have a 5cm range. The sensors does not tell you a range of distance but only tells you if things are in it’s way at a very fast rate.

I have one mounted on the bottom of the gripper for scanning the object, and one in the gripping path. There sensors are from Pololu

 

Demo

The grabber first uses the bottom sensor to check if it’s close to the floor, if so, the gripper path sensor would check if anything is in it’s path, If both requirements are met, the grabber would start gripping and grasp the object for 5 seconds and let go.