Dr. Heydari Gives Seminar Over Theory of Reinforcement Learning and Its Practice in Robotics and Autonomous Systems

Ali Heydari, Ph.D., an assistant professor of Mechanical Engineering at Southern Methodist University, gave a seminar on Monday, February 17th. He spoke about, “Theory of Reinforcement Learning and Its Practice in Robotics and Autonomous Systems.”

Abstract: Ali Heydari received his B.S. and M.S. degrees from Sharif University of Technology, Iran, in 2005 and 2008, respectively, and his Ph.D. degree from the Missouri University of Science and Technology, Rolla, Missouri, in 2013. He is currently an assistant professor of mechanical engineering at the Southern Methodist University, Dallas, Texas. His research is mainly focused on Adaptive Dynamic Programming and on applications of this machine learning scheme in robotics and autonomous systems. He serves on the editorial boards of IEEE Transactions on Neural Networks and Learning Systems and IEEE Transactions on Vehicular Technology.

Biography: Control plays the role of enabler in mechanisms in which, a parameter “changes”. For decades, a controller design was deemed successful, when the desired motion/change was achieved. However, today, the standards are much higher. “Qualities” including low energy consumption for a better range, human friendliness for safe and efficient interactions, high accuracy and productivity, high robustness to uncertainties and imperfections, and small footprint on environment are important “requirements” now.

Adaptive Dynamic Programming (ADP), also called Reinforcement Learning (RL), has a great potential to win in these new domains. The reason is, ADP/RL is motivated by nature, that is, the perfect way humans learn to operate machinery and control mechanisms. As an “intelligent control” tool, however, ADP/RL has been subject to shortcomings both in terms of its “rigor” (guarantees of desired performance) and its “scalability” (possibility of extension to challenging problems, beyond toy examples). An overview of my past and future research activities on resolving these two deficiencies will be presented in the seminar. Moreover, applications of the developed methods in challenging problems of autonomous systems and robotics will be discussed, including human-machine interaction and co-design of mechanisms and their controllers.

Oklahoma Aerospace Engineering Students Kickoff Design Project to Support International Space Station Resupply Missions

OU students travelled to Louisville, Colorado to meet with engineers at Sierra Nevada Corporation (SNC), and kickoff their capstone project work of designing ground support equipment for SNC’s Dream Chaser International Space Station resupply mission. Sierra Nevada Corporation is under contract with NASA to supply and recover payloads from the space station in support of NASA’s science and human spaceflight missions. Seven OU students from the Gallogly College of Engineering will spend their spring semester designing hardware to encapsulate and protect the Shooting Star cargo module of the Dream Chaser as it is prepared for flight.

Pictured from left to right: Chris Raatz (SNC), Brayden Cole, Alix Caudill, Sebastian Medina, Chandler Ziegler, Blake Mattioda, Patrick Turner, Abdelwahab Makhlouf, and Maggie Mueller (SNC)

This press release was written by Dr. Thomas Hays.

Dr. Jeongmoo Huh Gives Presentation Over Micro Propulsion Systems for the Next Generation Space Missions

On Friday, February 14th, Dr. Jeongmoo Huh gave a presentation over, “Micro Propulsion Systems for the Next Generation Space Missions.” Dr. Huh currently works in the Space Engineering Department in the Faculty of Aerospace Engineering at Delft University of Technology as a visiting researcher.

Abstract: Many miniaturized satellites have recently been launched and proved the feasibility of distributed space systems in space missions with improved revisit time, the time elapsed between observations by satellites, at an extremely low cost. Most preliminary small-scale satellites such as CubeSat and PocketQube, however, were either not equipped with a micro-propulsion system for its altitude/orbit control or not ready for various space missions due to inherent theoretical performance limitations of space propulsion systems that currently exist as well as limited performance achievement of micro propulsion systems. Not only normal operation of miniaturized satellites but also the next generation space mission using CubeSat/PocketQube will not be feasible without successful downsizing of space propulsion systems and their performance improvement.

The seminar will start with general principles of several chemical rockets and difficulties of downsizing of chemical rockets, and report how a chemical rocket was successfully miniaturized including a photolithography process, a MEMS (Micro-electro-mechanical Systems) based fabrication technology, and catalyst manufacturing process as well. Performance of thruster generation and propellant decomposition efficiency of 50 mN class MEMS-based monopropellant micro thrusters will be discussed based on experimental data showing how much performance was improved by using a blended propellant and regenerative micro cooling channels in micro scale thruster systems.

This will be followed by an introduction to electrospray micro colloid propulsion, one of space electric propulsion systems, which has arguably the highest specific impulse performance, up to a range of 1,500-7,000 s depending on electric power supplied. The different nature of the working principle of the system and its performance characteristics compared with chemical one will be identified. Pros and cons of chemical and electric propulsion systems will be discussed with inherent performance limitation of both propulsion systems, and a new system configuration for space micro propulsion will be suggested to meet the performance requirement of miniaturized propulsion systems for the next generation space missions, an interplanetary mission of miniaturized satellites.

Biography: Dr. Jeongmoo Huh currently works in Space Engineering Department in the Faculty of Aerospace Engineering at Delft University of Technology (TU Delft) in the Netherlands as a visiting researcher starting from July 2019. In Delft, He’s working on high energetic gel phase novel propellant development for space propulsion applications. Before joining the group, he worked as a postdoctoral researcher at Queen Mary, University of London (QMUL), in the UK from April 2017 to June 2019 participating in an electric propulsion project funded by the EU. The project was about high-performance low-cost disruptive propulsion technology using electrospray colloid propulsion for small-scale satellite applications. There was a consortium for the project and it was composed of a university, QMUL, and three different space-related companies, AirBus in the UK, NanoSpace in Sweden, and SystematIC in the Netherlands. The successful outcome is now on its way to commercialization. Dr. Huh stayed in Daejeon, South Korea for about 5 years from Feb 2012, for his graduate course and one year of postdoc experience. He received an M.S./Ph.D. degree in the Department of Aerospace Engineering from Korea Advanced Institute of Science and Technology (KAIST) in Daejeon in Feb 2016. For his Bachelor’s degree, he studied in the Department of Aerospace and Mechanical Engineering at Korea Aerospace University, Goyang, South Korea, from March 2008 to Feb 2012. His research topic in graduate school was about micro-scale chemical space propulsion for Nano-satellite applications, for which a MEMS(Micro-Electro-Mechanical Systems) fabrication process was designed and employed, validating successful manufacturing and operation of 50 mN class monopropellant thrusters with the suggested development procedure. As a postdoctoral researcher at KAIST, he also experienced classical size monopropellant, bipropellant, and hybrid propellant rockets and had hands-on experience on its application to sounding rockets, sounding rocket flight testing, and numerical code development for propulsion performance and flight performance estimation. One of his journal papers related to the micro chemical propulsion was selected as the best paper in Journal of Micromechanics and Microengineering at 2013 and 2014, and several conference papers related to micro propulsion, sounding rockets, and micro reactors were the best paper awarded and selected for further manuscript work at several international conferences held in the UK, France, Korea, and the US. Overall, chemical and electric space propulsion, sounding rocket systems, MEMS-based combustion and propulsion, and new energetic materials and novel propellants are what he has experienced and where his expertise lies in.

 

Brooke Owens Fellowship Recipient Encourages Others to Apply

This summer, aerospace engineering student Kaley Hassell participated in the Brooke Owens Fellowship Program. Now, she is encouraging other students to apply.

Hassell decided to apply for the Brooke Owens Fellowship program when she saw that it offered opportunities to work with amazing aerospace companies. She said, “the program is absolutely amazing for undergraduate women in aerospace.” Applications for the fellowship are open, and they close on November 12th.

As a selected fellow, Kaley Hassel worked with the engineering department at Sierra Nevada Corporation on the Dream Chaser spacecraft. She also got the opportunity to work with astronauts and CEOs.

Part of the Brooke Owens Fellowship Summit was the grand challenge presentation held in Washington D.C. “All of us were divided into groups and solved a grand challenge-or humanity’s next biggest feat,” Hassell said. “We got to present and network with a lot of cool people! We were tasked with solving how we could create a collaborative lunar economy. It was a lot of fun.”

Part of the Fellowship is being assigned a professional mentor. “Mine was Mr. Tory Bruno, CEO of the United Launch Alliance,” Hassell said. “It was really awesome getting to know and learn from him. He even invited me to observe mission control on the recent AEHF5 launch on August 8th!”

Kaley Hassell’s Experiences

NASA Administrator Mr. Jim Bridenstine keynote spoke to the Brookies at one of the fellowship dinners. “It was really cool,” Hassell said. “I learned a lot about how policy goes into the aerospace world and even got to ask him a question face to face!”

Hassell said the Brookies are definitely a family. She got to make some great connections with women from around the world who are passionate about making a change in the world of aerospace.

They also got to have a fireside chat with NASA Chief of Staff Janet Karika.

They also got to meet Oklahoma Representative Kendra Horn, and have a fireside chat with her about different space issues as well as learn from her successes and experience.

Kaley Hassell and her friend Ivy (another Brookie) with the Dream Chaser spacecraft. “I worked in the Systems Engineering department, solving problems and integrating between different systems,” Hassell said.

Pictured is the Brookie Class of 2019 at the Udvar-Hazy Center of the National Air and Space Museum. The Discovery space shuttle is in the background. “It was really cool to see it in person since I was basically working on a mini version of the Shuttle at SNC this summer!” Hassell said.

Robust Adaptive Controls for Shipboard Landing of Multi-Rotor Unmanned Aerial Vehicles

Alex Bryant and Lauren Ingmire in the lab.

A newly funded project in the School of Aerospace and Mechanical Engineering makes use of close collaboration between researchers in different fields to improve a critical technology for national defense. Dr. Keith Walters and Dr. Andrea L’Afflitto (now a faculty member at Virginia Tech) are combining their respective expertise in aerodynamics and controls to address a difficult challenge for unmanned aerial vehicles (UAVs).

It is well known that UAVs are increasingly being used for both commercial and military applications. The United States Department of Defense (DoD) currently employs multi-rotor helicopters (quadcopters) for remote sensing missions, such as surveillance and search and rescue. In the future, they will support troops by performing tactical tasks, such as picking up and dropping off payloads and surveying cluttered environments. Of particular interest are vehicles that operate autonomously, that is without any direct control by human pilots. These vehicles use onboard computers and mathematical control algorithms to perform necessary aerial maneuvers, travel to desired locations, avoid obstacles, and perform whatever tasks are required of their mission. The development of new and improved control algorithms is, therefore, an active area of research with the potential for substantial impact on next-generation UAVs.

This project focuses on the development of improved control algorithms specifically designed for the landing of UAVs on U.S. Navy ships. Shipboard landing is a complex task for UAVs because 1) the deck is highly unsteady in rough seas; 2) adverse sea conditions are often accompanied by adverse weather and high winds; 3) the superstructure of a moving ship induces a wake in the air, which further perturbs the UAVs landing on its deck; 4) near hard surfaces, the ‘ground effect’ alters the thrust produced by the propellers; and 5) UAVs returning from a mission may be damaged. To land on the deck of a ship, a UAV’s control system regulates the thrust forces of each propeller so that the aircraft approaches the ship with some desired relative velocity and orientation, leading to (hopefully) a gentle touch down in the appropriate location.

The primary objective of this research is to design a robust adaptive control system for multi-rotor UAVs that allows precise landing on the deck of moving ships. The work builds on prior research by former AME faculty member Andrea L’Afflitto and will make use of a model reference adaptive control (MRAC) architecture. Such an approach guarantees robustness of the closed-loop feedback system to both uncertainties in system parameters and unknown state-dependent disturbances that affect the control inputs, such as wind gusts or the swinging of an attached cargo payload.

The control algorithm will also be improved by adopting more realistic functional relationships between propeller rotational speed (RPM) and the generated thrust. Currently, it is assumed that thrust is simply proportional to RPM squared under all conditions. While this is often nearly true when a UAV is hovering in calm air, it does not hold during complex aerial maneuvers, under the action of strong wind disturbances, or when the vehicle is close to a solid surface such as the deck of a ship. Keith Walters and his students will perform computational fluid dynamics (CFD) simulations of quadrotor propellers to more accurately determine the relationship between thrust and RPM under these conditions. The simulations will be used to develop an analytical function that will be included in the control algorithm developed by Dr. L’Afflitto.

The scientific advances made by this project will be disseminated in the technical literature and will provide opportunities for graduate students to participate in national or international conferences. The improvement to UAV performance during shipboard landing will be critical to increasing the value of these vehicles to U.S. Navy missions, and the technology can be translated to other branches of the armed forces to improve design and operation of their next-generation UAV systems. Eventually, the research may be adopted by the commercial sector to improve, for example, the use of UAVs for package delivery or remote sensing in adverse weather conditions.

Undergraduate Rocket Research Group has Successful Launch

The University of Oklahoma’s Undergraduate Rocket Research group launched a rocket in Argonia, Kansas on March 10th, 2019. Dr. Thomas Hays and his students are proud of the results.

The rocket had a maximum speed of Mach 1.15 and weighed 105 pounds. The students involved in the launch were Kaley Hassell, Jarod Manning, Alex Speed, and Scott Tesser. Congratulations on your successful launch!

Click here to watch the video of the rocket.

Two AME Alumni Inducted into the GCoE Distinguished Graduates Society

 

AME Alumni Michelle Coppedge (pictured) and Freda Webb will be inducted into the Distinguished Graduates Society of Gallogly College of Engineering.

Michelle Coppedge received her bachelor’s degree in 1988 for mechanical engineering. She is currently the director of Mike Monroney Aeronautical Center – Federal Aviation Administration and serves on the AME Board of Advisors. Freda Webb received her bachelor’s degree in mechanical engineering in 1979. She is the Vice President of Operations for Panhandle Oil and Gas, Inc.

In 1990, the College of Engineering established the Distinguished Graduates Society to honor our most accomplished alumni. Selection is based upon prominent and distinguished professional or technical achievement, notable public service, outstanding contribution to and support of education, honors of election in organizations, and other contributions to the engineering profession. (GCoE)

Greg Williams Receives Staff Merit Award

AME Shop Machinist Greg Williams received the 2019 Staff Merit award on April 24, 2019.

Greg Williams is from Oklahoma City. He has worked at OU and AME for 17 years. Mr. Williams enjoys working with the people at AME as well as the flexibility and variety in his position as a Machinist in the AME Shop. Outside of AME, Mr. Williams enjoys spending time outdoors.

Congratulations Greg!

BBDL Students Give Presentation at Moore Norman Technology Center

On March 14th and April 9th, Dr. Lee and students from the Biomechanics and Biomaterials Design Laboratory (BBDL) provided presentations to the Moore Norman Technology Center (MNTC) pre-engineering students.

These presentations provided the MNTC students with some insight into the regular week-to-week life of a college student, and the learning experiences that the BBDL students had throughout their college careers. They also emphasized how valuable undergraduate engineering is to personal/professional growth and how easily one can get involved. Additionally, the BBDL students talked about their ongoing work in cardiovascular and brain aneurysm biomechanics and how the basic engineering principles span a diverse array of applications.

WindBAG- Pre-Capstone Project

This year, the Pre-Capstone Principles of Engineering Design class is revolved around Project WindBAG, the central semester-long team-based project. This project is designed to provide students with the opportunity to act as junior engineers exploring solutions to a complex, multi-level, and competency-building program.

The students are given a task to design, build and test a system capable of converting wind energy into some more useful form of energy and then storing this energy in some compact, transportable module. The wind source is represented by a household electric fan, and the energy modules must be used to propel a vehicle, carrying as large a payload through as many loops around a track as possible, subject to the restrictions and conditions.

One component of the experience is that the problem revolves around a central narrative. This narrative provides the opportunity to diagram the problem within its complete context, just as problems in the real world exist within particular contexts. This experiential learning provides the basis on which competencies will be further developed.