Case Study: Industrial Automation Brings Animatronic Robot Alive

Summary

Science fiction, particularly in movies featuring robots like R2-D2 and WALL-E, has inspired countless young people to become engineers, and perhaps many dream of one day building their own ‘bot. While sci-fi-inspired engineers go on to do great things, few actually build their own personal animatronic robot, especially one that matches up with its more famous on-screen robo-counterparts.
 
Growing up, I consumed science fiction and enjoyed frequent family trips to theme parks. But unlike the general public—although certainly like many readers of this publication—I tended to find the animatronics and control systems behind these attractions to be more fascinating than the rides themselves. Disney’s Carousel of Progress was especially intriguing, as its robotics seemed way ahead of the times.
 
Later in life, I gained technical training in the Air Force and college credits through Augusta State University and other institutions, plus years of hands-on work in the industrial automation profession. However, I always wanted to develop my own personal robot. Even with the proper inspiration, skills, and determination, building a full-sized animatronic robot is a massive and not-inexpensive undertaking. Here is how I carried out this dream over many years.
 

Automation inspiration

My ambition was to create Hubert—full name Hubert Evolution 2, or HEV2—to be reminiscent of the charismatic Johnny 5 from the 1986 movie Short Circuit (See figure 1 at the top of the article). While this wasn’t a formal educational project, and instead much more of a way to get out of the books, I was able to receive school credit for certain elements of the build as it evolved. The work started in 2006 when I was a student, and continued as a part-time project until around 2020, for roughly 15 years of development.

As I progressed professionally in the OEM automation industry, I gained skills at work and with my Hubert project that translated back and forth. I love robotics and automation, but I would never claim this project has been easy, having poured countless hours into design, fabrication, and programming. However, the learning opportunity has been invaluable. My strong mechanical aptitude and various technical experiences have been instrumental, and this project has included a lot of research and testing.
 
The design started small, but I knew that expanding it to full-size would be expensive. I began with the frame, a sort of cart or chariot made from aluminum extrusions, as the foundation for building all the automation. I knew that I wanted Hubert to have a movable torso, limbs, head, and other features. Sometimes, parts could be cheaply obtained from eBay, but this wasn’t always the case. Consumer-grade hobby servos were also useful.
 
As I researched automation technologies, I quickly concluded that I should use commercial off-the-shelf (COTS) products to the greatest extent possible, avoiding extensive experimentation with custom board-level electronics and coding. For these and other reasons, I soon graduated to using more capable control electronics, software, electro-mechanical hardware, and pneumatics, much of it industrial-grade COTS parts.
 

Industrial-grade tech supports animatronic capabilities

My research led me to rely on AutomationDirect for evaluating and obtaining a wide variety of automation and controls components. Although some of the earliest Hubert components were decidedly consumer-grade finds, the move to incorporate industrial-grade AutomationDirect hardware and software was a natural fit. The website has a wealth of technical information, support videos, and other resources, which helped me select components and implement new programming.
 
Designing Hubert was a very process of continual improvement. For instance, I started with small hobby servos, which needed a DC servo controller. To command this controller, I discovered that I could send it serial strings and produce a wide range of motions. At some point, I landed on stepper motors and drives as another economical way to produce motion.
 
Initially I did not use dedicated motion controllers. Instead, I found that the AutomationDirect CLICK Koyo programmable logic controller (PLC) was easy to use, offered exceptional flexibility for the price, came with free software, and was ideal for generating serial strings and interacting with drives using high-speed input/output (I/O) signaling. As the I/O count kept growing, I used AutomationDirect ZIPLink pre-wired cables and connectors to improve organization.
 
As the project progressed, I moved into using pneumatics. While pneumatics are less accurate than servos or steppers, they are a powerful way to achieve motion. Linear pneumatic actuators, combined with position feedback and Nitra valves, have provided the best way to move Hubert’s limbs, and the compressibility of air allows them to move with a more organic feel than electrical options.
 
Soon, I was trying much more advanced algorithms. I was already using a good amount of geometry and trigonometry in the code, and I began using proportional-integral (PI) control native to the PLC, and experimenting with time-proportioned loop control. The goal was to produce smooth and natural movement, with the ability to hold a pneumatic cylinder at the commanded position within a few millimeters. But as the code base and device count grew, Hubert needed more brainpower, so I moved up the AutomationDirect Productivity3000 modular PLC combined with an AutomationDirect C-more human-machine interface (HMI) to provide a convenient user visualization and data/command entry method (Figure 2).

Building a ‘bot into a career

Developing Hubert has been a labor of love over the course of 15 years. Built largely with industrial automation components, it has been an excellent learning experience with highly relevant crossover to my professional job. Is Hubert complete? Not really; future plans include updating the HMI, adding EtherNet/IP-controlled valve banks, integrating a more advanced ProductivityMotion PS-AMR4 4-axis motion controller, using a 3D printer and CO2 laser to manufacture additional components and an outer shell, and more.
 
Most recently, I bought gloves fitted with potentiometers, and integrated these so my hand motions can be used to teach and record motion for Hubert to execute later. I have also worked to create “scenes” of smaller movements, which can be invoked as needed.
 
The ready accessibility and usability of AutomationDirect products have been foundational this project, and they make a great platform for anyone who is curious or aspires to innovate using automation technologies. I hope that Hubert inspires folks to create new projects of their own because it opens up new career and other opportunities.
 
_{All figures courtesy of Justin Flynn}