Roach-inspired robots designed to help in emergencies

When disaster strikes, help in an emergency situation can be somewhat challenging. Living in an area that is frequently stricken with earthquakes has prompter one engineer to develop a device to help locate people who may be trapped in buildings.

Small, disposable mobile robots can collaborate to move around challenging terrain.

Electrical engineer Ronald Fearing turned to nature for his robotic design inspiration, specifically insects, as they are able to work and live in the most uninhabitable places. Fearing developed a tiny breed of robots that can fit in the palm of your hand and help in emergency situations.

“Living in earthquake country in California,” Fearing says, “it’s frustrating to know people will be trapped after a building collapse. We have an indeterminate amount of time to find someone before they may die. Small robots would allow us to get in and communicate fairly quickly.”

Fearing has a long history of developing biomimetic robots. Along with his team at the University of California, Berkeley, he has designed robots that share similar traits with insects, lizards and other animals.

With emergency response in mind, Fearing created a biologically inspired team of robots that are able to travel on tough terrain while sending and receiving information and guidance from rescue personnel. In conjunction with the National Robotics Initiatives (NRI), the team looked to the indomitable cockroach as one insect model for his group’s designs.

Fearing and the team developed a series of robots about 3-10 centimeters long that move like the common cockroach Periplaneta Americana, sharing its gait stride frequency and other dynamics. The range of robotic capabilities were determined by how each size would function within the team.

Fearing and graduate students Aaron Hoover and Erik Steltz used the smart composite microstructure (SCM) process to create the roach-like bots. SCM is a rapid prototyping method in which rigid structure and movable joints are laser cut from a single sheet of material and then folded into position.

The 3 cm miniRoACH is slow. Fearing and graduate student Duncan Haldane, with fellow students Fernando Garcia Bermudez and Kevin Peterson, adapted the movement of the original RoACH for the larger VelociRoACH, a 10 cm robot that can run almost 3 meters per second (approximately 6 mph).

The VelociRoACH research was made possible by an NSF Integrative Graduate Education and Research Traineeship (IGERT) award to teach biology and engineering students to learn from natural design.

In order for the X2-VelociRoACH model to go faster than nature’s design, Fearing and Haldane added a bigger motor and more power to increase stride frequency. In 2015, the little robot reached speeds up to 5 meters per second (approximately 11 mph), making it the fastest legged robot relative to its size.

These tine devices have mastered fast movement in flat, open environments. Currently, the team is developing locomotion in tough environments with little open space, obstacles everywhere and no clear paths through. The robots need to explore in order to reach their destinations.

Typical rescue robots are designed for particular terrain, require costly motors and joints, and are much larger and heavier. Fearing and his collaborators use less complicated, more versatile designs for robots that work together.

The team’s design strategy was centered around one question: What if robots encounter an obstacle they’ve never seen before?

Fearing and his team study strategies that teams of robots can use to overcome a variety of obstacles. Ants provided some inspiration, as they often collaborate (for example, by stepping on each other) to get where they need to go.

Fearing, along with graduate student Carlos Casarez, tested a strategy for robots that aren’t specifically designed to climb or step over obstacles. The researchers outfitted two VelociRoACH robots with radios, leg-position sensors, gyroscopes and accelerometers to help them orient themselves. They also gave the VelociRoACHes a small tether and winch system, giving them the ability to latch onto and pull one another. The team then explored how simple actions — motion primitives — could be combined to help the robots reach their goal.

With the right primitives, arranged in the right order, the robot team could cooperate to reach the top of a step, then disconnect and continue exploring separately. Over the next year, Fearing and his team will test instructions for robots to push, pull, twist and execute other cooperative movements.

Fearing hopes that these tiny bots will help in search and rescue situations. Deploying tens or hundreds of small robots at a time means that they can quickly cover a large search area. And Fearing points out that from a cost point of view, simple robots are $10 to $100 each instead of $1,000 each. Fearing is looking to develop a backpack filled with a complete set of robots and a tablet interface that first responders can easily carry and use at the scene of an emergency.

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