Robotic Arms in Manufacturing

Introduction

A robotic arm, sometimes referred to as an industrial robot, is often described as a ‘mechanical’ arm. It is a device that operates in a similar way to a human arm, with a number of joints that either move along an axis or can rotate in certain directions. In fact, some robotic arms are anthropomorphic and try and imitate the exact movements of human arms. They are, in most cases programmable and used to perform specific tasks, most commonly for manufacturing, fabrication, and industrial applications. They can be small devices that perform intricate, detailed tasks, small enough to be held in one hand; or so big that their reach is large enough to construct entire buildings.    

Robotic arms were originally designed to assist in mass production factories, most famously in the manufacturing of cars. They were also implemented to mitigate the risk of injury for workers, and to undertake monotonous tasks, so as to free workers to concentrate on the more complex elements of production. These early robotic arms were mostly employed to undertake simple, repetitive welding tasks. As technologies develop, in particular robotic vision and sensor technology, the role of robotic arms is changing. This article provides a brief overview of Robotic Arms in manufacturing.  

History of Robotic Arms in Manufacturing

It is widely understood that the first programmable robotic arm was designed by George Devol in 1954. Collaborating with Joseph Engelberger, Devol established the first robot company, Unimation in 1956, in the USA. Then in 1962 General Motors implemented the Unimate robotic arm in its assembly line for the production of cars. A few years later, a mechanical engineer at Stanford University, Victor Scheinman was developing a robotic arm that was one of the first to be completely controlled by a computer in 1969. This industrial robot, known as the Stanford Arm was the first six axes robotic arm and influenced a number of commercial robots that followed.  A Japanese company, Nachi, developed their first hydraulic industrial robotic arm in 1969 and after this a German firm, Kuka, pioneered the first commercial six axes robotic arm, called Famulus, in 1973.

Predominantly, these robots were utilised for spot welding tasks in manufacturing plants but as technology developed, the range of tasks that robotic arms could perform also expanded. The advances in technology includes the increasing variety in end-of-arm tooling that has become available. This means that Robotic arms can perform a wide range of tasks beyond welding depending on the tools that are attached to the end of their arms. Current innovations in end of arm tools include; 3D Printing tool heads, heating devices to mould and bend materials, and suction devices to fold sheet metal. You can read more about advances in end of arm tooling in the article on designrobotics.net, Design Robotics in Architectural Fabrication.

Advancements in Sensors and Vision Robotics

A very  important advancement in the use robotic arms is the development of sensors. Victor Scheinman developed the Silver Arm in 1974, which performed small-parts assembly using feedback from touch and pressure sensors. Although early robots had sensors to measure the joint angles of the robot, advances in robotic sensors have had a significant impact on the work that robots can safely undertake. Here is a summary of some of these sensors and what affordances they provide.

  • 2D Vision sensors incorporate a video camera which allows the robot to detect movement over a specific location. This lets the robot adapt its movements or actions in reference to the data it obtains from the camera.
  • 3D Vision Sensors are a new and emerging technology that has the potential to assist the robot in making more complex decisions. This can be achieved by using two cameras at different angles, or using a laser scanner to provide 3 dimensional views for the robot.
  • A Force Torque sensor, helps the robotic arm to understand the amount of force it is applying and allows it to change the force accordingly.
  • Collision Detection sensors provide the robot an awareness of its surroundings.
  • Safety Sensors are used to ensure people working around the robot are safe. The safety sensors alert the robot if it needs to move or stop operating if it senses a person within a certain range.

There are many other sensors available which include tactile sensors or heat sensors. The benefits of these different types of sensors for robotic arms is that they provide the robot with detailed and varied  information from which it can make decisions. The more information the robot has available to it, the more complex decisions it can make. Ultimately the purpose of these sensors is to help make working environments around robots safe for people.

Design Robotics Research Project

Vision technology makes working with and alongside robots safer, but it also assists robotic arms is making complex decisions for manufacturing. This means developing the capability for mass customisation manufacturing, which means that they can create high volumes of bespoke and customisable items for mass consumption while keeping fabrication costs low.

The Design Robotics projects is researching how vision technology and robotic arms can improve manufacturing outcomes for small to medium enterprises who are fabricating bespoke, one off items. Working with Urban Art Projects, this is research is being tested through the manufacture of large scale, unique public art projects.   

 

Further Reading:

Evolution of Robotic Arms: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4247431/

History of the Kuka Arm: https://www.kuka.com/en-au/about-kuka/history

History of Nachi: http://www.nachirobotics.com/company-information/natchi-history/

Robots and their Arms: http://infolab.stanford.edu/pub/voy/museum/pictures/display/1-Robot.htm

History of the Robotic Arm: source: http://iptmajorprojectjacobheffernan.weebly.com/history-of-the-robotic-arm.html

Seven Types of Industrial Robot Sensors: https://blog.robotiq.com/bid/72633/7-Types-of-Industrial-Robot-Sensors

Working alongside robotics (interview with Peter Corke) http://media.theaustralian.com.au/poweringaustralia/robotics/index.html