Put this case on, and the mobile phone will “run” to recharge itself

When the whole small robot is not mounted on the mobile phone case, it weighs about 23 grams, and can move forward at a speed of 21cm per second under the condition of loading 300g: < / P > < p > it is not uncommon for a micro robot with a mechanical leg to move forward on its own. Many teams have developed corresponding products. But the overall structure of these robots is irregular and cannot be integrated into a mobile phone case. < p > < p > the biggest highlight of casecrawler’s technology is that its mechanical leg can be extended and flattened when it is still. The gear set that transmits power from the gearbox to the leg is only 1.5mm thick, but its thin mechanical structure is quite strong. < / P > the principle of a human leg bending forward is similar to that of a mechanical leg. < / P > < p > the anisotropic leg connected to the leg joint only transmits force to the ground when moving forward; the knee joint is passively bent when ascending to avoid backward force. A part of the kinematic chain is a crank slider mechanism, which transmits the torque of the motor to the rest. Therefore, the swing motion of the rest parts is realized while the extension and retraction are repeated. < / P > < p > in addition, the designed motion chain moves in a whole plane, and achieves high load capacity by minimizing the lateral deformation of the joint. < / P > < p > the robot consists of two motors; each motor is responsible for driving the legs on both sides of the robot, and the rotation speed difference of the two motors realizes the robot’s steering. < / P > < p > three 3:1 pinions are placed in series to minimize the height, so the gear ratio is 27:1. SCM process is adopted in the fuselage to reduce the height as far as possible, and the groove for installing the sports chain is laid on the fuselage. < / P > < p > the kinematic chain is composed of crank slider and outrigger chain, which is used to transfer the torque of motor to the anisotropic outrigger. The crank slider and deployable foot chain are made of pet and fabric monolayer. < / P > < p > the sliders are stacked between two parallel planes as linear guides for the slider; these guides produce smooth motion. Therefore, in the fully retracted state, a plate with a thickness of 1.5 mm is formed. < / P > < p > the design of the chain link meets the kinematic constraints, and the range of motion of the joint is 0 to 90 degrees. The minimum angle is set at 0 degrees to keep the compactness in the initial state; the maximum angle is set at 90 degrees to prevent the structure from being damaged. < / P > < p > the crank slider and leg links are coupled, so they should be calculated together. From the two distal conditions of the joint angle, the kinematic constraint can be written as: < / P > < p > where the variable L1 represents the length of the slider of the crank connecting rod. L2 is the length of the connecting rod, L3 is the length of the sliding rod, L4 and L5 are the height of the leg link device, h is the height of the body, and l is the length between the input gear and the joint. < / P > < p > at present, the casecrawler robot is still controlled by the remote control, and all it can do is walk and load. < / P > < p > in the future, the research team plans to interconnect the robot with various sensors of the mobile phone, such as cameras, gyroscopes, etc., and use the robot as a multifunctional loading platform to enter a very narrow environment for shooting and other operations. However, if AI models such as target recognition are mounted on the gait and path selection algorithm of the robot, the practicability of casecrawler can be further improved, and the automatic path finding without manual operation can be realized. < p > < p > the first author, jongeun Lee, is an assistant professor at Yushan University of science and technology, and a researcher in the laboratory of biological robotics, Seoul National University. Kyu Jin CHO, tutor, associate professor of mechanical and aerospace engineering, Seoul National University, director of soft robot research center and director of biological robot laboratory. His research interests include bionic robots, soft robots, soft wearable devices, novel mechanisms using intelligent structures, and rehabilitation and assistive robots. Skip to content