The skid plate is used to protect the blades, but it also protects the object being hit. How did the robotic lawn mowers perform?

We demonstrated for the first time our Hedgehog prototypes performing controlled hopping and tumbling in comet-like environments," said Robert Reid, lead engineer on the project at JPL.

Acknowledgments

The percentage distribution of tests resulting in damage to the hedgehogs, defined either as damage category 4 or damage category 3 + 4. Damage category A was omitted from the analyses, leaving the total number of tests between 9 and 12 depending on the amount of damage category A results recorded per robotic lawn mower. The lower percentage of cases of damage during the tests, the safer the robotic lawn mower. The robotic lawn mower models have been listed in accordance with the percentage distribution of damage defined as damage category 3 + 4. Models showing the lowest damage percentage are listed first. Robotic Lawn Mowers Sophie Lund Rasmussen holds a PhD in biology and hedgehog ecology from University of Southern Denmark and Naturama. She will continue her research on The Danish Hedgehog Project as a postdoc at Aalborg University and WildCRU, Oxford University from September 2020, where she will conduct research into accumulation of poisons in hedgehogs. Martínez, J.C.; Rosique, A.I.; Royo, M.S. Causes of admission and final dispositions of hedgehogs admitted to three Wildlife Rehabilitation Centers in eastern Spain. Hystrix Ital. J. Mammal. 2014, 25, 107–110. [ Google Scholar] This spiky cube of a robot is being developed by NASA with Stanford University and MIT. Hedgehog is designed to explore small bodies, such as asteroids or comets. These have very little gravity and extremely rough terrain. Instead of rolling, Hedgehog hops and tumbles. The completion of the book was then delayed by not just the Covid pandemic but also David’s own successful battle with cancer.

Yes! These are called humanoid robots. There are some tasks for which a robot that moves more like a human might be best. For example, we might like a humanoid robot to help prepare a future human settlement on Mars. With such tasks in mind, NASA’s Johnson Space Center has developed a robot named R5, or Valkyrie. In the light of the results the next important step is to communicate the new insights to the manufacturers, enabling them to improve future machines to become more hedgehog friendly. A total of 18 models were included in the test and each robot was tested 12 times. The hedgehogs had been divided into four weight classes and the robots were tested on each weight class. The hedgehogs were also placed in three different positions to mimic real conditions. The majority of hedgehogs may simply run away and thereby avoid collisions. Healthy hedgehogs are perfectly able to outrun a robotic lawn mower – they have surprisingly long legs hidden underneath all those spines. NASA has been investigating Mars with rovers since the Pathfinder mission landed in 1997 and deployed a small rover called Sojourner. Credit: NASA/JPL-Caltech.

To answer this question, Dr. Rasmussen and her team of researchers thoroughly investigated 18 models of robotic lawn mowers in collision tests with dead hedgehogs. The dead hedgehogs in the study were collected from hedgehog rehabilitation centers, where sadly they had been too poorly to save. Each robotic lawn mower was tested 12 times; with four dead hedgehogs representing four different weight classes, each tested in three different positions.