Flipping beetles inspire self-righting robot design
Image credit: L. Brian Stauffer
Engineers at the University of Illinois at Urbana-Champaign have taken inspiration from beetles in order to design robot prototype parts to help them right themselves after toppling over.
In July, a penguin-shaped security robot was reported to have fallen into a fountain in an office reception and “drowned”. Unable to right itself, the unwieldy robot became essentially useless and had to be rescued by its human colleagues.
While robots like these have many abilities humans are not capable of – such as collecting and storing huge amounts of data – they also lack some abilities that are entirely instinctive to humans and other animals. This includes the ability to recover from a fall, which is a tricky mechanical problem.
In order to help robots with wheels or limbs to recover from tipping over, mechanical engineers and entomologists at the University of Illinois joined forces to study the ability of click beetles to right themselves without using their legs.
“The idea came to life when a group of insect physiology students decided to take a closer look at what makes click beetles jump as part of a class project,” said Dr Marianne Elleyne, an entomologist who teaches a bioinspiration course at the university.
“Very little research had been performed on these beetles, and I thought this legless jumping mechanism would be a perfect candidate for further exploration in the field of bioinspiration.”
This group of insects are named “click” beetles due to a useful hinge-like mechanism, mostly employed for avoiding predators, but also for righting themselves without their legs. A spine on the upper thorax is snapped into a notch, producing a strong, loud click that catapults the bug into the air, so it can land safely back on its feet.
The Illinois researchers studied different species of click beetles, from ones the size of a lentil to bugs several centimetres in length.
“Each insect goes through an assembly line of analyses that involve basic characterisation, high-speed filming to observe the jump and measurements in the Materials Tribiology Lab […] to determine how much force it takes to overcome the friction of the hinge within an individual beetle’s jumping mechanism,” said Professor Aimy Wissa, mechanical engineer and lead investigator.
“We observe, model and validate each stage of the jump with the hopes that we can later integrate them into a self-righting robot.”
Based on this study, the interdisciplinary team were able to build bioinspired prototypes of a spring-loaded hinge device which can be incorporated into a robot. Once installed, this could allow the robot to recover from falls and continue operations without having to be rescued.
“The study is a two-way street, engineers are informing the biologists and vice-versa,” said Professor Wissa. “We look forward to seeing where this research will take us.”