Picking up a cup of coffee is not difficult for an ordinary person, but it has been a tricky problem for robots in the past thirty years. Recently, researchers from Harvard and Yale universities in the United States are developing a new robotic arm that can solve this problem. Inspired by the structure of the mantis legs, engineers have designed a robotic arm that is not only more sensitive, but also more suitable for robots that cannot express themselves.
Robert D. Howe, the leader of the Bionic Robotics Laboratory at Harvard University, and Aaron Doral, an assistant professor at Yale University, are jointly committed to the development of robotic arms. They believe that humans have been studying robotic arms for nearly 20 to 30 years, but the manufactured robotic arms are rarely able to complete dexterous movements. In reality, both robots and humans face certain difficulties in establishing the connection between the hand and the object to be grasped. Humans compensate for this mistake by opening their fingers to make them flexible and flexible, allowing them to slide along the edges of objects before gripping and picking them up; The traditional method of robot technology research in response to errors is to use a large number of sensors, motors, and controllers, which results in complex and expensive mechanical arm structures. Due to the need for a large amount of computer operations to complete the simplest tasks, this type of robotic arm moves more slowly. If a robotic arm is used to lift a wine goblet, unless it is moving at a snail like speed, the robotic arm will have knocked the goblet over before the sensing signal is transmitted back to the computer and reacted.
The inspiration for the unexpected design by researchers came from the leg structure of praying mantis. They chose the completely opposite approach, completely transforming the robotic arm through the bionic leg structure of praying mantis, allowing it to automatically adjust to grasp various shapes of objects. In the 1980s, Professor Robert from the University of California, Berkeley, began studying how mantis walk on rough surfaces. Mantis' brains are very small, and Robert believes they cannot calculate agile actions so quickly. He analyzed the mechanical structure and working principle of the legs of praying mantis, and research showed that their legs are flexible and flexible. This structure allows praying mantis to automatically adjust to rough object surfaces without considering it. Robert imitated machine legs using springs and hinges, and created an eight legged robot that walked at astonishing speed on rough surfaces, something that no robot had ever achieved before.
Robert's research shocked the robotics community, and Doral and Howe decided to create robotic arms using similar methods. If the appropriate spring and finger shape and size can be selected, the robotic arm will become flexible and can slide along the edges of the object to grasp it, just like a human lifting a coffee cup. Firstly, they control two double connected plastic fingers and a separate motor through cables and pulleys, and then add another set of fingers for stable grasping. Despite having only a four finger structure, the final robotic arm possesses several characteristics of a human hand. In addition, the joints of the robotic arm can be opened from 25 degrees to 45 degrees, and the joints at the base of the fingers are more flexible than those of the fingers. The designer also installed sensors to sense the angle at which fingers touch objects and joints. although The designer also installed sensors to sense the angle at which fingers touch objects and joints. Although there are still many minor issues with the automatic adjustment of the robotic arm, sensors can compensate for some major errors. Ultimately, this simple robotic arm can deftly complete the task of grasping most objects, providing a development platform for future home service robots. Researchers have also applied this technology to prosthetic limb research, with a significant advantage of less than 42.5 grams per finger, as many amputees give up using prosthetics due to their bulky and inconvenient nature. At present, the robotic arm is not yet proficient in grasping small objects such as keys and forks, and completing these dexterous movements requires the installation of additional motors, which will increase the weight and complexity of the robotic arm. Researchers are exploring a new construct with a reversible thumb to solve this problem. In the past thirty years, people have made robots more complex in order to improve their functions. The research results of Doral and Howe have opened up a new idea for the robotics community, and there is still a long way to go. Related information: Diagonal arm robotic arm Dongguan robotic arm accessories Horizontal walking robotic arm