From the Roomba to the Mars Rover, robots are an important part of our modern society. They are used to facilitate efficient mass production, they assist our soldiers in combat situations and they explore parts of our planet and cosmos that are impossible for humans to reach. Though these machines perform their specific tasks very well, they have very little room for variation. There is another branch of robotics that focuses on robots that perform multiple tasks in many environments: modular robots.
UC Davis researchers have recently created a modular robotic system, named iMobot. A modular system is like building with a ton of identical Lego pieces. The pieces fit together to make an infinite number of arrangements. This means that multiple iMobots can be combined to perform many different tasks.
“Now-a-days, there is greater interest in modular robotic systems because they provide greater flexibility,” said Harry Cheng, a professor of mechanical and aerospace engineering at UC Davis, and co-inventor of the iMobot. “We are trying to develop reconfigurable systems that can be configured for different tasks.”
An individual iMobot unit, rectangular in shape, has two joints in the center section, and a wheel on each end. This allows the iMobot to drive on its wheels, make crawling-like motions, and elevate one end of its body.
“A single iMobot has four controllable degrees of freedom, or ways that it can move,” said Graham Ryland, a UC Davis alumnus and co-inventor of the iMobot.
To put that in perspective, a pair of scissors has only one joint, so it has one degree of freedom. But the human body has hundreds of degrees of freedom.
The motions the iMobot can make are similar to the ball-joint of the human shoulder.
“If you attach a gripper onto the end of it, it almost looks like it has a wrist, and it can go through the whole motion that an arm can go through,” said Ryland.
One of the purposes of the iMobot is to study bio-mimetics, or machines that resemble biological creatures. Biomimetics can be used to study the locomotion of a snake’s body or the human gait.
Multiple iMobot units can be connected in either as a series and in parallel. Units connected in series would resemble a snake, with one unit attached to the end of another unit. There is theoretically no limit to how many units can be connected, but as more units are added, it becomes a difficult engineering and programming task to make the units move synchronously.
If scientists need to lift a payload, iMobot units can work together to raise it above the ground. If the weight is too much for units connected in a series, other units can be connected in parallel, or side-by-side, with the current units. If two units are connected, the lifting strength is doubled. If three are connected, the strength is tripled, and so on.
The primary goal of this project was to create a mass-produced modular system that can be used by other researchers. Users can integrate ultrasonic sensors, infrared sensors, gravity sensors, accelerometers or any other kind of sensor.
“There are so many applications, and it all depends on the sensor information,” said Cheng. “That is the flexibility that we provide.”
A modular, artificially intelligent can also “self-heal,” which means it can replace its own parts if it malfunctions.
Cheng believes that robotics is a perfect field for interdisciplinary research. His proof lies in the UC Davis Robotics Club, which has over 100 members from many different majors.
“We’ve created a robotic system that is an open canvas that doesn’t limit the creativity of the user,” Ryland said.
The researchers have filed a patent, and have started a company, Barobo Inc., so that they can begin commercial production of the iMobot.
HUDSON LOFCHIE can be reached at science@theaggie.org.
