Wisdom

Robotics in Motion: Manipulator Systems with the Wrist

Welcome Back! Over the last two weeks, we started our journey into robotics with a few simple elements concerning motion. Last week we tackled the motion of the Arm/Body. This week we go final step within the maipulator systems.

Before, we’d said that one of the main components needed to move a robot was a manipulator of which there are essentially two types: arm/body & wrist.

Whereas last week we covered the arm, this week we tackle the wrist. Again, remember that Manipulators are essentially created by linking together solid component parts and/or joints to allow motion between consecutive links. And, that Manipulators are subdivided into two primary component systems: Arm/Body & Wrist.

Robotic arm in a factory. Modern heavy industry, technology and machine learning

There two or three compact joints formulating the wrist, whereby tools/parts can be oriented in a finer fashion. Ultimately, the wrist is where all the detail work of the robot can be done. For the Wrist, just as for the Arm/Body, there are specific types/categories that help us understand and classify the movement they create based on how the joint(s) is(are) arranged. Furthermore, the movement is defined within one of three spectrums as the rotation moves around:

Around the Wrist, Circular Spin= roll.

Top-to-Bottom axis = pitch.

Side-to-Side = yaw.

Starting at 0:47 seconds in the video below we can see a clear vision of each of the three.

_{Thanks to Engineering Technology Simulation Learning Videos}

As a three-part combination, with varying selections from the three movements above, we create the two main wrist compositions:

Roll-Pitch-Roll Combination, AKA – A Spherical Wrist that goes spin, top-to-bottom (looks side-to-side below), spin.

Moving something like this…

_{Thanks to Thang010146}

Pitch-Yaw-Roll Combination that goes top-to-bottom, side-to-side, spin.

Going something like this…

_{Thanks to Jeroen Houwers}