Reinventing the Steel

Sorry, Spot. After a look at research underway at the Statler College of Engineering and Mineral Resources, one might think that humanity has a new best friend in robotic form.

There, robots are all the rage as engineers shepherd us into the future by developing machines that do more than shake a paw or roll over: They pollinate plants, explore space and enhance mine safety, just to name a few applications.

These tall tasks, cumbersome for even humans, become a breeze in the hands of robots, propelling aspirations forward and our understanding of how robotics can contribute to the global community and beyond in meaningful ways.

ROBOTS, OUR POLLINATION PLAN B

A shortage of natural pollinators, such as bees, continues to threaten global food production, making it difficult to feed an ever-growing human population. Stickbug is a plan B to this decline in pollinators.

Yu Gu and Jason Gross, associate professors in the Department of Mechanical and Aerospace Engineering, are the brains behind StickBug, a six-armed robot that can pollinate crops in greenhouse environments.

Stickbug’s six arms, according to Gu, are intended to improve the efficiency and effectiveness of the robot. For example, some flowers could be in hard-to-reach places and the robot may need to use two arms: one arm for grabbing the branch, and the other arm to pollinate the flower. The robot is responsible for the time-consuming tasks of flower inspection, mapping, ollination and development tracking. This allows growers the freedom to focus on other greenhouse tasks like planting, irrigation and pest control.

“It (StickBug) maps out the environment and once the robot has a general idea of the environment, it will build up a more detailed mapping of the plants and knows where the flowers are and which flower needs to be pollinated,” Gu said. “It will make a plan on what to do. Then, it will get close to each of the plants, start swinging its six arms and start pollinating.” The long-term goals for this robot are to care for individual crops efficiently, improve food security during insect declines, support indoor agriculture and provide services beyond what insects can do such as collecting data on the crops.

“It (StickBug) maps out the environment and once the robot has a general idea of the environment, it will build up a more detailed mapping of the plants and knows where the flowers are and which flower needs to be pollinated,” Gu said. “It will make a plan on what to do. Then, it will get close to each of the plants, start swinging its six arms and start pollinating.” The long-term goals for this robot are to care for individual crops efficiently, improve food security during insect declines, support indoor agriculture and provide services beyond what insects can do such as collecting data on the crops.

“[The]tomato is probably one of the most economically-important crops in the country and it also needs help for pollination,” Gu said. “Another major reason is that tomato plants [grow] year- round. There are always tomato flowers to do experiments on.”

According to the USDA Forest Service, about 80% of all flowering plants require assistance from animals for pollination and, without pollinators, many crops cannot propagate.

With the aid of robotic pollinators, Gu said growers can overcome the shortage of pollinators and obtain higher profit opportunities by planning flexible pollination schedules independent from the activity of pollinators.

“There’s a very high percentage of crops that rely on pollination and so it’s quite conceivable to think in the future that there could be a potential shortage [of pollinators],” Gu said. “That could have some importance for needing this robotic pollination technology.”

“Agriculture is a field that is very ripe for disruption with robotics and automation,” Gross said. “The hope is that a lot of those challenges with perception and manipulation and interacting with the plant will be more widely applicable to a lot of different robotics agriculture applications.” While West Virginia is a primarily rural state, it is not an agricultural state, meaning that it imports more food than it produces. Gu hopes that this robotic pollination technology can support more people in the state to have their own venture in agriculture.

For WVU specifically, Gu and Gross said that the robot pollinator also provides educational opportunities for students.

“WVU allows us to do cutting-edge research,” Gu said. “[This project] provides an opportunity for students to do both hands-on and theoretical research in robotics as well.”

Gu said specific programs will also be developed to integrate the engineering and skilled labor training domains so that future training aligns with the rapidly advancing use of robotics. “One thing that we’re really excited about is that this project really fits well with being a land-grant institution,” Gross said. “We have the second round of a partnership with our robotics faculty, and our agricultural and design faculty. We get to leverage the fact that WVU has a state- of-the-art research greenhouse for robotics research. Those are all things that I think make it really exciting to be at WVU.”

OUT-OF-THIS WORLD INNOVATION

Robotics research at WVU isn’t reserved just for one planet.

Gu is working alongside Guilherme Pereira, associate professor in the Department of Mechanical and Aerospace Engineering, to create control software for a group of aerial robots (aerobots) that will survey the atmosphere of Venus, the second planet from the sun.

Venus went through a climate change process that transformed it from an Earth-like environment to an inhospitable world. Studying Venus can help model the evolution of climate on Earth and serve as a reference for what can happen in the future.

Gu and Pereira are developing the software for the aerobots, which are balloon-based robotic vehicles, and they hope to play a pivotal role in these discoveries. Their study is supported by a $100,000 NASA Established Program to Stimulate Competitive Research.

“The main goal of the project is to propose a software solution that will allow hybrid aerobots to explore the atmosphere of Venus,” Pereira said. “Although hybrid vehicles were proposed before this project, we are not aware if any software has been created.”

One aerobot concept is the Venus Atmosphere Maneuverable Platform, a hybrid airship that uses both buoyancy and aerodynamic lift to control its altitude.

The benefit of a hybrid aerobot is its ability to, during the day, behave like a plane, collecting and using energy from the sun to drive its motors, and, during the night, float like a balloon to save energy.

The buoyancy of the vehicle would prevent it from going below 50 km – or 31 miles, below the surface of Venus where the temperature is very high and would damage the vehicle, according to Pereira.

“One of the ideas of our project is to extend the battery life of the vehicle by planning energy-efficient paths, thus allowing it to fly during the night as well,” Pereira said.

The aerobot lifespan at cruise altitude is several months to a year.

Pereira and Gu said their software will have three main goals. The first is to create a motion planner for the vehicles, so they can be commanded to go from their current position to a goal position specified by NASA’s science team using minimum energy and leveraging the winds in the planet. The motion planner is a software that will run in the aerobot’s computer.

“The motion planner will be created by understanding the dynamics of the aerobot, the properties of its solar panels and batteries and the properties of Venus’ atmosphere,” Pereira said. “With the dynamics of the vehicle, the planner will only consider movements that are feasible given certain inputs to the aircraft, such as thrust coming from the propellers or deflections of the control surfaces.”

Pereira said that understanding the solar panels and batteries is important to account for how much charge the vehicle has to power its systems and what its recharging rate is according to the solar intensity.

“The understanding of the atmosphere provides the robots quantities like wind direction and magnitude, pressure, temperature and solar intensity,” Pereira said.

With these models, the motion planner will calculate the best route for the aerobot.

“We are trying to come up with an optimal energy strategy,” Pereira said. “This is important since the vehicle will be orbiting the atmosphere of Venus in around four days. It will be exposed to long periods without light on the dark side of the planet and it needs to have enough energy to survive these periods.”

According to Pereira, the motion planner will have access to the position of the aerobot in Venus’ atmosphere and to a desired goal location. It will also have access to information about the atmosphere in between these two positions.

“Starting from the initial position, the planner will simulate different movements the aerobot could make and associate costs for each of them depending on the quantities mentioned before,” Pereira said.

For example, if the wind is blowing in the same direction as the movement of the aerobot, that would be less costly than moving against the wind direction.

Pereira added, “After that, the motion planner will keep propagating the movements of the aerobot with smaller cost, creating a tree of possibilities until we reach our destination.” The second goal of this project is to localize the aerobot vehicles in the atmosphere using information from other vehicles and maps of the planet. There is currently no GPS for Venus, so localization is difficult.

This localization approach will allow several robots to be less lost as a group when they are exploring Venus. Gu and Pereira plan on using different types of maps for localization. “We are evaluating the possibility of using maps created before the mission, most likely a Venus topographic map to help the robots to localize themselves,” Gu said.

The third goal for this project is to coordinate the vehicles so that they have improved localization and a better estimation of atmosphere conditions.

The spatial distribution of the aerobots in the atmosphere may allow each aerobot to have a better knowledge of the 3D wind field if each vehicle shares the wind flow in its neighborhood, according to Pereira.

Pereira and Gu’s research will be based on wind models of Venus created by NASA. The researchers also propose that the aerobots carry wind sensors that can be used to estimate the local wind.

“The importance of the wind flow is related to the fact that it can be exploited to take the aerobot to desired locations,” Pereira said. “Just as with sprinters in the Olympics when they get better marks if they are experiencing tailwind. If the wind is directed towards the goal of the aircraft, the aerobot movement will be aided by the wind and, by consequence, the path will be more energetically efficient.”

To test this, Pereira and Gu plan to develop a Venus atmosphere simulator, where they will evaluate the aerobots’ functionality.

“Several exploratory missions to Venus collected data of wind, temperature, pressure and air density,” Pereira said. “This information was then used to create a simulator where, given the latitude, longitude and altitude of the vehicle, we compute all the forces acting on the vehicle.”

AN UNDERGROUND SAFETY NET

Roof collapses and falling debris are a main cause of injuries and deaths in underground mines. Researchers believe those catastrophes can be prevented by using robots and drones to monitor the structural integrity and safety of underground mines.

Ihsan Berk Tulu, assistant professor of mining engineering from the Department of Mechanical and Aerospace Engineering, along with Gross, Gu and Pereira, is developing an autonomous robotic system to do just that.

By using a combination of remote vehicles that consist of an unmanned aerial vehicle attached to an unmanned ground vehicle, the team will provide high-resolution 3D maps for assessment of pillar and roof damage.

The researchers were awarded a $750,000 grant from the Alpha Foundation to conduct this research on the health and safety of underground miners.

“Ultimately, this project will develop an early warning system that will notify the mine engineers for elevated hazardous conditions in underground stone mines,” Tulu said.

According to Tulu, in underground mines in the United States, “fall of ground”- related accidents are one of the leading causes of injuries. This occurs when part of the roof or a pillar collapses. Although underground stone mines have generally experienced good ground stability, a recent mine pillar collapse in Whitney, Pennsylvania, and reported roof fall accidents in other mines highlight the potential safety impact on the miners.

“The autonomous robotic early warning system for monitoring stone mines will enable a rapid response to detected degradations in pillar and roof stability,” Tulu said. “Successful development and deployment of this system is expected to reduce injuries of underground stone mine workers.”

“While the initial problem is associated with pillar stability and design, the techniques developed in this research would be easily adaptable to the underground coal and metal/ nonmetal mining sectors,” Tulu said. “The autonomous robots mapping ability would also be adaptable to facilitate search and rescue efforts in case of an accident.”

The researchers will leverage similar technology to what is currently under development for underground tunnel rescue operations by the WVU Robotics Team to develop the robotic system. The system will then be deployed to Laurel Aggregates underground stone mine in Lake Lynn, Pennsylvania, for testing.

THINK LIKE AN ANIMAL

One engineer is combining neuroscience and robotics to better understand the nervous system and motor output of insects to create animal-like robots for use in agriculture, mining and space exploration.

To create mobile robots, Nicholas Szczecinski, assistant professor in the Department of Mechanical and Aerospace Engineering, will investigate how animals, particularly stick insects and cockroaches, measure and respond to forces acting on their legs as they walk.

With the aid of a $630,000 award from the National Science Foundation, Szczecinski will work with a six-legged robot model whose control system is based on the nervous system of an insect, enabling the researchers to integrate dynamic force sensing into the robot’s control system. “Because stick insects have been studied so closely, much is known about how their sensory systems, nervous systems and muscle systems operate during walking,” Szczecinski said.

“Therefore, if one wants to build a robot that can walk over and naturally on inclined terrains or climb on unstructured environments, a stick insect is a good animal to seek inspiration from.” Szczecinski and his team’s most recent robot models the leg of the walking stick insect, Carausius morosus. The robot was created by scaling up the geometry of the leg, ensuring that it experiences the same dynamics as the animal’s leg, and adding sensors along the leg like those on the animal.

“Stick insects’ legs share some geometric similarities with ours. Their legs attach to their body with a very flexible joint, much like a human’s hip. We built a robot leg with the same proportions and joints as a stick insect leg, but about 15 times larger, which makes it easier to build and modify,” Szczecinski said.

Because the robot leg is heavier and larger than that of an insect, the researchers slow down the motion to ensure that the leg experiences very small forces from inertia, which is similar to the real insects’ actions.

The robot also needs to sense the environment like the animal. Insects can sense the rotation in their joints, much like humans, and they have an extra type of sensor called Campaniform Sensilla that measures the bending of their exoskeleton.

“These sensors are very important for walking because they help the animal measure and regulate the forces acting on the leg,” Szczecinski said. “To mimic this, the leg has four different strain gauges mounted in the same positions and orientations as the major Campaniform Sensilla groups on stick insects’ legs. As a result, the leg can sense the same things as the animal.” Szczecinski said the main purpose of creating this robot is to combine what is known about insect locomotion into one model, and then use the model to collect data that would be challenging to collect in the animal.

“We hope that we can apply what we learn to the construction and control of new robots that can walk capably over difficult terrain,” Szczecinski said.

According to Szczecinski, when faced with difficult terrains like those found on the moon and Mars, robots with legs would enable space agencies to scale mountains or canyon walls across the solar system. On Earth, the robots with legs would also enable farmers to grow crops more densely and naturally on inclined terrains.

“Currently, crops are grown in a spreadout way to ensure that wheeled tractors can drive between them. However, growing crops this way does not permit plants to grow how they prefer, in dense groups. Wheel ruts draw moisture away from crops and since they are exposed to the sun, the water evaporates. Farm equipment with legs could enable farmers to plant crops in different patterns that support plant growth and hydration.”

Szczecinski hopes that rather than replacing people from these jobs, more agile robots could supplement the workforce.

The researchers will take two approaches to detect how dynamic force sensing affects muscle control — one experimental and the other based in robotics. The experimental approach will involve inserting electrodes into the muscles of insects’ legs to measure the electrical activity of the force sensors. The second approach will incorporate dynamic load into existing robot control systems to measure the robot’s energy expenditure and agility as it walks over different terrains at different speeds.

“The end result of this research that excites me the most is to give robots a more naturalistic sense of force detection and touch,” Szczecinski said.

As part of the project, the researchers will carry out various outreach events in West Virginia schools by using Lego Mindstorm kits to expose students to the mechanics and programming behind robotics.

“We hope that our outreach workshops will teach students how to boil tasks down into a set of logical instructions, which underlies all of robotics and automation,” Szczecinski said.