Alumni Q&A: Paul Evans

Engineering Grad Designs Robots for Tough Tasks

By: Loree Chase-Waite

Evans, a mechanical engineer with Southwest Research Institute® (SwRI®) in Texas, and his colleagues developed the world’s first fully-automated aircraft depainting system.

As part of a maintenance schedule, military aircraft get a makeover.
No, it’s not a cosmetic luxury; it’s a maintenance requirement.

In order to maintain performance and conduct a variety of critical maintenance procedures, the old paint must be stripped off. It’s a time-consuming, labor-intensive process that can be dangerous for humans.

Enter Paul Evans ’95, WWU mechanical engineering graduate and robotics expert. At Southwest Research Institute® (SwRI®) in Texas, he and his colleagues developed the world’s first fully-automated aircraft depainting system.

Currently used at Hill Air Force Base in Ogden, Utah, a custom two-robot system can depaint about 100 F-16 Falcon aircraft each year. And at Robins Air Force Base in Warner Robins, Ga., a custom three-robot system can depaint about 50 F-15 Eagles each year.

We asked Evans about his role in this project and others—and discovered some fascinating facts.

Why is it helpful for robots, instead of humans, to depaint aircraft?
When humans do the job, they have to suit up in protective clothing, including an enclosed helmet with breathing hose, to avoid direct exposure to the dust-laden air.

And then, with limited visibility, the operators must scale up and down ladders and across platforms, using a heavy hose to forcefully blast the paint off, all the while managing their own breathing hose.

Robots, of course, don’t have lung concerns, which increases worker safety. Robots are also more efficient. And they can be programmed to depaint a variety of aircraft and parts. Experts estimate that robots save up to thousands of dollars per aircraft in labor and other indirect costs.

What are some of the unique ways that these robots have been programmed?
Each robot has nine motors that give us the ability to position it anywhere within the work area. Software in the robot controller coordinates the motion of all these motors so that the very end of therobot arm can travel in a straight line.

Also, we use sensing techniques to monitor the process and control the speed of the robot. If the paint is tough and hard to remove, the software can tell the robot to slow down. If the paint is thin or easy to remove, the software can tell the robot to speed up. This is a good way to optimize the amount of time required to depaint an aircraft.

What is blasted to remove the paint?
We use a dry media blast process. It’s essentially like sand blasting, but with plastic or corn starch. High-pressure air moves the dry media through the hoses and out the nozzles. A single robot carries multiple nozzles, whereas a person is only able to handle a single nozzle.

We have also demonstrated that lasers are viable for depainting aircraft. The laser process is starting to gain acceptance with the U.S. Department of Defense because it has the promise of being more controllable for removing advanced coatings and processing delicate surfaces.

What happens to the old paint and other dry media? How is it collected and where does it go?
The dry media falls into a large grating on the floor under the aircraft. Then it goes through a screening process to filter out the paint particles and separate out the good media, which can be used again, from the media that is too small or too worn to be reused. The waste is then collected and used as an additive for new products such as plastic lawn chairs, plastic fence posts, and concrete blocks.

With laser removal, the paint particles are reduced into a very fine particulate that is vacuumed up by a dust collection unit.

How do the robots know when the job is done?
The robots follow a pre-programmed path—or set of waypoints—in a sequence. So once the robots have processed all the waypoints, the job is finished.

You also helped develop a robotic device for a NASA project called DepthX (short for DEep Phreatic THermal eXplorer). What was the goal of the project and how were you involved?
NASA scientists would like to explore what is beneath the ice layer on Europa, the sixth moon of Jupiter. The idea behind DepthX was to develop an autonomous system that could explore and identify life here on Earth in an unexplored environment. That would be a precursor, then, to a future robotic mission to Europa.

I managed the robotics and automation engineering section, which was responsible for the environmental sensor suite, sampling arm, and sample collection.

How does the robot look for and retrieve samples for analysis?
Using sensors and computer algorithms, the robot seeks out places in the environment that have visual or sensory indications of life. Then, when the robot finds an area of interest, it automatically approaches the wall, extends the robotic arm, and collects a core sample. In the deepest known sinkhole in the world located in the northeastern state of Tamaulipas, Mexico, where the robot was field tested, it also collected water samples. We developed an on-board microscope system that autonomously analyzed those samples for microbial life.

Have the changes at NASA affected how and where the device is being used?
The program here on Earth was viewed as a success and portions of the robot were repurposed for research in Antarctica.

As you’ve worked on robots, have any spiritual or life lessons occurred to you?
I have always had an appreciation for the complexity of human life. And working on electromechanical systems has strengthened that view. The systems we develop are complex and take years to develop—yet they barely scratch the surface of intelligent machine control.

This reinforces my faith that a more intelligent and omnipotent force is at work to enable the creation and sustainment of life. For me personally, it takes less faith to believe that human life was created by God, even though this view is not shared by the majority of the scientific community.

Are you doing things to improve manufacturing in the United States?
My department at SwRI works directly with small- and medium-sized manufacturers to help them become more competitive. We have the privilege of operating the South Central regional office of TMAC which is an affiliate of the Manufacturing Extension Partnership (MEP), which is run by the National Institute of Standards and Technology (

The MEP is a public/private partnership that delivers a high return on taxpayer investment. For every federal dollar invested, the MEP generates $32 in new sales growth. Ultimately, this results in $3.6 billion in new sales annually for U.S. manufacturers.

Looking at those numbers, it appears that manufacturing in the U.S. may be more robust than we think.
It’s true that many people don’t realize how important manufacturing is to our nation’s economy. I must cite a few interesting facts from the National Association of Manufacturers:

* The U.S. is the world’s largest manufacturing economy, producing 21 percent of global manufactured products. China is second at 15 percent, and Japan is third at 12 percent.
* U.S. manufacturing firms have the most productive workers in the world—twice as productive as workers in the next 10 leading manufacturing economies.
* Nearly 12 million Americans (or 9 percent of the workforce) are employed directly in manufacturing.

Speaking of manufacturing, you are invested in a very non-industrial company in Texas—creations of a culinary nature.
Yes, I am one of the partners of Green Vegetarian Cuisine, a restaurant in San Antonio.

My interest stems from a lifetime of vegetarianism. In 2006, my business partner became a vegetarian and sold his diner. Together we decided to expose San Antonio, a city known for its chicken-fried steak and carne guisada, to a diet that doesn’t involve animal products. So far the concept has been well-received, and we just opened our second restaurant.

The menu looks fantastic. Do you eat there often? What is your favorite meal?
I eat there about once a week. I love the Rueben sandwich—fresh purple sauerkraut on toasted bread with chipotle mayo. I recommend the kale salad as a side; it has a delicious dressing.

The Web site ( mentions that the restaurant is closed on Saturdays.

Yes, we get questions about why we are closed on Saturdays. Our staff knows that this is a day of rest and they, too, have grown to appreciate the fact that we set this day aside from work. Our patrons are sometimes disappointed, but ultimately we would not have it any other way.

Can you tell us about your family?
My wife Ellen and I have two boys, 1 year and 3 years of age. Ellen owns an online maternity clothing business called Bloom Maternity and does some consulting in the field of social media. So, when the weekends roll around, we all come together as a family to relax together, play together, and rejuvenate.

How do you hope your career touches the lives of others?
Practically, I want to use engineering, manufacturing, and robotics to solve our customer’s toughest technical problems while also helping advance science and technology. Most great developments, of course, are not individual efforts. All of the project examples I have described have required expertise from a variety of people and disciplines. Teamwork and collaboration is critical to the advancement of science and technology.

Personally, I hope that some of the cool project examples I am able to share will help inspire students to explore a career in engineering. It is extremely exciting to be on the cutting edge of technical applications and development. There is nothing better than seeing new products or applications grow from concept to something that is of real value to real people.

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