Benefits of Using a Parallel Robot Gripper

What’s the benefit of a new type of robot gripper? The newest addition to the Robotiq family — the Hand-E Adaptive Gripper — answers this age-old question.

We have just released our Hand-E Adaptive Gripper. It’s a translational, parallel gripper. You might be wondering what makes it so special compared to our existing range of Adaptive Grippers, which are rotational, parallel grippers.

Related: How to Measure ROI for Robotics Training

You might also be wondering: Why should I use a translational gripper when the rotational grippers are so popular?

In this post, we tell the story of how these two types of gripper came into being and we address the question “Do I need a translational or a rotational gripper?”

Hand-E is the first UR+ gripper ready for the new Universal Robot e-Series

In the beginning: there was a problem with pneumatic parallel grippers

The question of “Which parallel gripper is best?” is a long-standing one. It stretches all the way back into the last decade.

The story starts with a related question: “Which is better: pneumatic grippers or electric grippers?”

You see, Hand-E is certainly not the first translational, parallel robot gripper on the market. In fact, the first ever industrial robot, the Unimate, had a rigid parallel gripper. For years, the vast majority of grippers were pneumatic — 80% in 2011, according to an article which was written in that year. While there were some advantages to pneumatic actuation (e.g. faster actuation times and lower cost), these grippers were not very flexible.

Traditional pneumatic parallel grippers had several problems:

  • They were usually supplied with no fingertips — only an actuation block — so you had to make your own custom fingertips for every task.
  • They lacked precise control, being either fully open or fully closed.
  • They required compressed air which was a pain if you didn’t have pneumatics already installed.
  • They had no built-in grip detection.

An alternative is born: Robotiq’s adaptive grippers

When Robotiq started making grippers a decade ago, our CEO, Samuel Bouchard, wanted to overcome the limitations of pneumatic grippers. In previous articles, he has explained the advantages of electric grippers and the problems with pneumatic grippers. He and co-founder John-Philip Jobin focused on making adaptive electric grippers which were inherently flexible and could be used out-of-the-box.

Since then, we have become renowned for our 2-Finger and 3-Finger Adaptive Grippers. Some of the unique properties of these grippers are:

  • Wide stroke, which can just as easily pick up both large and small objects.
  • No need for customized fingertips (unless you want them). You can attach the gripper in minutes and start using it immediately.
  • Their patented mechanical linkage design means they can grip unknown items securely. See Mathieu’s article for details about how the grippers work.
  • Parallel grip and encompassing grip. This linkage design also means they can grasp objects with two grips: a parallel grip and an encompassing grip.
  • Integrated part detection, position feedback and part validation.

Our existing grippers are also parallel grippers. Their fingers are constructed using parallel linkages which allow the fingertips to follow an almost-linear motion. However, the motion of the fingers follows a slight curve, which can make it challenging to use them for high-precision tasks.

Our electric grippers showed that you didn’t need pneumatics to have a high performance, lightweight, reliable gripper at a reasonable cost. They also showed that adaptivity is very important, especially in high-mix environments where various objects need to be manipulated by the robot.

The world changes… and a new need appears

When Robotiq began, we were up against the received wisdom that pneumatic grippers were better than electric… boy, did we show that to be wrong!

The world has changed a lot since the early days of Robotiq. These days, electric grippers are quickly becoming the norm in some parts of industry.

Back in 2013, experts stated “The reasons why pneumatic grippers dominate electrical grippers are obvious” claiming they were more reliable, faster and offered more size options. Now, in 2018, those reasons are no longer so obvious, with experts explaining “Electrical grippers have clear advantages over pneumatic grippers…since electrical drives and motors are becoming smaller, lighter, and more powerful.”