Design and experimental validation of an electromagnetic launching mechanism for a tethered net

High-altitude rescue is dangerous and difficult. A new rescue method is proposed here based on electromagnetically launched tethered nets. Four electromagnetic launching units are attached to a revolving platform, from which four projectiles are launched. The four projectiles are connected to a tethered net, bringing it into motion. As the tethered net approaches and comes into contact with the object, the object will be trapped, and the rescue task will then be completed as long as the tethered net can be restored along with the trapped object. The structural design of the electromagnetic launching unit is presented with the established mathematical model. The motion characteristics of the launched projectiles are studied and their exit velocities are modeled and measured. Terminal velocities of these projectiles are characterized, and the final shape and position of the projected tethered net are obtained. This study validates the feasibility of using electromagnetically launched tethered nets to perform high-altitude rescues.