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A robot dog with a virtual spinal cord can learn to walk in just one hour

<p>We’ve all seen those adorable clips of newborn giraffes or foals first learning to walk on their shaky legs, stumbling around until they finally master the movements.</p> <p>Researchers wanted to know how animals learn to walk and learn from their stumbling, so they built a four-legged, dog-sized robot to simulate it, according to a new study <a href="https://www.nature.com/articles/s42256-022-00505-4" target="_blank" rel="noreferrer noopener">reported</a> in <em>Nature Machine Intelligence</em>.</p> <p>They found that it took their robot and its virtual spinal cord just an hour to get its walking under control.</p> <p>Getting up and going quickly is essential in the animal kingdom to avoid predators, but learning how to co-ordinate leg muscles and tendons takes time.</p> <p>Initially, baby animals rely heavily on hard-wired spinal cord reflexes to co-ordinate muscle and tendon control, while motor control reflexes help them to avoid falling and hurting themselves during their first attempts.</p> <p>More precise muscle control must be practised until the nervous system adapts to the muscles and tendons, and the young are then able to keep up with the adults.</p> <p>“As engineers and roboticists, we sought the answer by building a robot that features reflexes just like an animal and learns from mistakes,” says first author Dr Felix Ruppert, a former doctoral student in the Dynamic Locomotion research group at the Max Planck Institute for Intelligent Systems (MPI-IS), Germany.</p> <p>“If an animal stumbles, is that a mistake? Not if it happens once. But if it stumbles frequently, it gives us a measure of how well the robot walks.”</p> <figure class="wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio"> <div class="wp-block-embed__wrapper"> <div class="entry-content-asset"> <div class="embed-wrapper"> <div class="inner"><iframe title="Learning Plastic Matching of Robot Dynamics in Closed-loop Central Pattern Generators" src="https://www.youtube.com/embed/LPL6nvs_GEc?feature=oembed" width="500" height="281" frameborder="0" allowfullscreen="allowfullscreen"></iframe></div> </div> </div> </div> </figure> <p><strong>Building a virtual spinal cord to learn how to walk</strong></p> <p>The researchers designed a <a href="https://cosmosmagazine.com/health/machine-learning-tool-brain-injury/" target="_blank" rel="noreferrer noopener">learning algorithm</a> to function as the robot’s spinal cord and work as what’s known as a Central Pattern Generator (CPG). In humans and animals, the CPGs are networks of neurons in the spinal cord that, without any input from the brain, produce periodic muscle contractions.</p> <p>These are important for rhythmic tasks like breathing, blinking, digestion and walking.</p> <div class="newsletter-box"> <div id="wpcf7-f6-p198628-o1" class="wpcf7" dir="ltr" lang="en-US" role="form"> </div> </div> <p>The CPG was simulated on a small and lightweight computer that controlled the motion of the robot’s legs and it was positioned on the robot where the head would be on a dog.</p> <p>The robot – which the researchers named Morti – was designed with sensors on its feet to measure information about its movement.</p> <p>Morti learnt to walk while having no prior explicit “knowledge” of its leg design, motors, or springs by continuously comparing the expected data (modelled from the virtual spinal cord) against the sensor data as it attempted to walk.</p> <p> “Our robot is practically ‘born’ knowing nothing about its leg anatomy or how they work,” Ruppert explains. “The CPG resembles a built-in automatic walking intelligence that nature provides and that we have transferred to the robot. The computer produces signals that control the legs’ motors and the robot initially walks and stumbles.</p> <p>“Data flows back from the sensors to the virtual spinal cord where sensor and CPG data are compared. If the sensor data does not match the expected data, the learning algorithm changes the walking behaviour until the robot walks well and without stumbling.”</p> <p>Sensor data from the robot’s feet are continuously compared with the expected touch-down data predicted by the robot’s CPG. If the robot stumbles, the learning algorithm changes how far the legs swing back and forth, how fast the legs swing, and how long a leg is on the ground.</p> <p>“Changing the CPG output while keeping reflexes active and monitoring the robot stumbling is a core part of the learning process,” Ruppert says.</p> <p>Within one hour, Morti can go from stumbling around like a newborn animal to walking, optimising its movement patterns faster than an animal and increasing its energy efficiency by 40%.</p> <p>“We can’t easily research the spinal cord of a living animal. But we can model one in the robot,” says co-author Dr Alexander Badri-Spröwitz, head of the Dynamic Locomotion research group.</p> <p>“We know that these CPGs exist in many animals. We know that reflexes are embedded; but how can we combine both so that animals learn movements with reflexes and CPGs?</p> <p>“This is fundamental research at the intersection between robotics and biology. The robotic model gives us answers to questions that biology alone can’t answer.”</p> <p><img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=198628&amp;title=A+robot+dog+with+a+virtual+spinal+cord+can+learn+to+walk+in+just+one+hour" width="1" height="1" /></p> <div id="contributors"> <p><em><a href="https://cosmosmagazine.com/technology/robot-machine-learning-to-walk/" target="_blank" rel="noopener">This article</a> was originally published on <a href="https://cosmosmagazine.com" target="_blank" rel="noopener">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/imma-perfetto" target="_blank" rel="noopener">Imma Perfetto</a>. Imma Perfetto is a science writer at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.</em></p> <p><em>Dynamic Locomotion Group (YouTube)</em></p> </div>

Technology

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Mum taken over by paralysis on drive home

<div class="post_body_wrapper"> <div class="post_body"> <div class="body_text redactor-styles redactor-in"> <p>Queensland mother of two Roisin Clark, 35, has been left heartbroken and in shock after an accident left her paralysed for life.</p> <p>She had just undergone her first surfing lesson in December 2019 where she felt some pain in her back.</p> <p>Brushing it off, her best friend made the five-minute drive home back to Roisin's house where she had lost all feeling from her ribs down.</p> <p>“I thought I was struggling to walk (to the car) because of the pain but in actual fact I was going paralysed,” Roisin (pronounced Roshine) told<span> </span><a rel="noopener" href="https://7news.com.au/lifestyle/health-wellbeing/qld-mum-of-two-paralysed-from-ribs-down-in-freak-accident-during-first-surfing-lesson-c-2649456" target="_blank">7NEWS.com.au.</a></p> <p>She's replayed that day over and over again in her mind, but was surprised to remember that there were no big waves that she thought could have caused the injury.</p> <p>“About halfway through, I started to get lower back pain,” she said.</p> <p>“I mentioned it to the instructor. He said it was quite normal and asked if I wanted to continue.</p> <p>“I said yes, (because I) didn’t think it was serious.”</p> <p>Roisin continued to brush off the pain, despite not being able to get out of the car when she arrived home.</p> <p>“I went to get out of the car and I couldn’t get out. It was just crazy,” she said.</p> <p>“I lifted my legs to the side of the car and went to stand up and couldn’t.</p> <p>“I fell onto the driveway (and) lay on the driveway.’</p> <p>“I still at this point didn’t think it was serious.”</p> <p>It was only after she was rushed to the hospital and had doctors questioned her that she started to believe it was serious.</p> <p>“I kept getting asked ‘so there wasn’t a big wave?’” Roisin recalled. “Once they saw there was no broken bones, they got the neurologist because they knew it was a spinal cord issue," she explained.</p> <p>“The night after (being admitted to the ER), doctors told me there was nothing more they could do. With the spinal cord, it’s fairly instant. Once there’s damage to it, it’s difficult to recover.”</p> <p>Despite spending five months in hospital recovering, she's not out of the woods yet.</p> <p>“There is so much more to having a spinal cord injury than not being able to walk.</p> <p>“Being in a wheelchair for me, means not only being unable to move or feel touch in my legs but also from my ribs down. It means the loss of bladder and bowel function, body temperature regulation and secondary complications like pressure sores,” Roisin said.</p> <p>“One of the hardest parts is constant and debilitating nerve pain. I spent five months in spinal rehab learning a whole new way of life - the simplest things like rolling over in bed, sitting up, showering, toileting, dressing and transferring into a car.”</p> <p>The family are now appealing for help via<span> </span><a rel="noopener" href="https://www.gofundme.com/f/helproisindriveagain" target="_blank">GoFundMe</a><span> </span>to buy a new car so that it can be modified and Roisin can help out at home, with the Clark family hoping to raise $45,000.</p> <p>“I’m not sure what the future looks like but if I could have some independence back and get out of the house ...(it) will make such a difference to our lives,” she said.</p> <p><em>Photo credits: 7NEWS</em></p> </div> </div> </div>

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