Magnets in drones play a crucial role in their usage. This article will introduce the roles of magnets in drones.
Types of Magnets in Drones
| Neodymium Magnets: Brushless DC (BLDC) motors are popular for drones because they provide higher propulsion. Due to their high power-to-weight ratio and efficiency, neodymium magnets are widely in drones’ BLDC motors.
| Alnico Magnets: Alnico magnets are known for their good temperature stability and can maintain their magnetic properties even at higher temperatures. Drones can perform in severe environmental conditions such as high-altitude operations.
| Samarium–Cobalt Magnets: Samarium–cobalt (SmCo) magnets in drones have exceptional magnetic stability, even under extreme conditions like corrosive environments.
| Ferrite Magnets: Ferrite magnets in the motors are a good way to keep production costs down. They are used to fix auxiliary equipment, such as cameras.
Shapes of Magnets in Drones
| Bar Magnets In Drones: These are commonly used in drone motor rotors to provide a magnetic field around the stator.
| Irregular-Shaped Magnets: Designed to fit into special-shaped spaces or to enhance magnetic field intensity.
| Arc-Shaped Magnets: Used in permanent magnet motors of drones, helping maintain consistency in the stator and rotor air gap, improving overall motor performance.
| Circular Magnets In Drones: Primarily used in drones to fix accessories.
Applications of Magnets in Drones
Propulsion System
Almost all modern drone propulsion systems use brushless motors, which are safer, more efficient, and quieter than brushed motors.
A four-digit number typically describes brushless motors—for example, 1204 or 2104. The first two digits (12 or 21) indicate the stator (coil part) diameter in mm. The last two digits (04) refer to the height of the rotor’s internal magnets, also in mm. Larger first two digits mean a thicker motor body and larger last two digits mean a taller motor body.
| A thicker motor body with more coils and a longer magnetic moment arm provides more power but consumes more energy.
| A longer motor body results in stronger magnetic force and higher torque.
The University of California has successfully created the world’s smallest drone. This drone has a wingspan of just 9.4 millimeters and weighs only 21 milligrams. The drone is not equipped with a battery; instead, it has two miniature magnets built in. Under the influence of an external magnetic field, the magnets drive the propeller blades to rotate, providing the lift necessary for the robot. By precisely adjusting the magnetic field strength, researchers can control the flight path of the drone, effectively managing its movement trajectory.
Background Knowledge
Micro magnets are also known as tiny magnets. Their dimensions are less than 1mm. A variety of shapes are available: micro ring magnets, micro disc magnets, micro block magnets, micro cylinder magnets, etc.
Navigation System
In the drone field, magnetic navigation technology is primarily used to assist the Inertial Navigation System (INS) in measuring and correcting heading angles, improving drone flight stability and accuracy.
The technical principle involves using a magnetometer onboard to measure the intensity and direction of the Earth’s magnetic field, combined with an Earth magnetic field model, to calculate the drone’s heading information.
Magnets in the magnetometer mainly stabilize and enhance signals, helping the magnetometer more accurately identify and parse subtle changes in the Earth’s magnetic field to calculate precise direction and position information. Additionally, the use of magnets can help the magnetometer resist external magnetic field interference, improving its reliability and accuracy under various environmental conditions.
Stabilization System
Magnets also play a crucial role in drone vibration control and stability improvement through electromagnetic damping.
Placing a closed coil next to a moving magnet will quickly stop the magnet. Similarly, placing a magnet around a moving metal block or coil will quickly stop its motion. Electromagnetic damping essentially converts mechanical energy into electrical energy through electromagnetic induction, which is ultimately dissipated as electrical heat, quickly stopping mechanical movement.
By adding electromagnetic dampers to the drone structure, the electromagnetic force generated by the interaction between conductor plates and magnets within the damping unit suppresses vibrations. The closer the conductor plate is to the permanent magnet, the greater the damping force, causing the plate to stop more quickly. This enhances the drone’s flight stability, allowing it to flexibly avoid obstacles in various complex spatial environments.
Speed Control System
The Electronic Speed Controller (ESC) is an electronic circuit designed to change the motor’s speed and direction and can also serve as a brake. It converts DC power into three-phase AC to drive the motor. The ESC is an important component of modern drones, providing high-power, high-frequency, high-resolution three-phase AC to the motor.
New electronic speed controllers use arc-shaped magnets instead of traditional square motor configurations, employing closed-loop torque control and unique functions that additionally enhance motor performance and ensure motor safety.
Fixing System
Magnets in drones can also be used for drone accessory fixation, utilizing the attraction between magnetic flux and metal parts. By installing magnetic fixing devices on the drone’s body or bottom, accessories like cameras and payloads can be easily attached and detached, improving the drone’s flexibility and versatility. Designers can adjust the type and size of magnets and optimize the material, thickness, and flatness of the adsorption surface to create different magnetic attraction forces.
In conclusion, magnets provide crucial support for performance improvement and multi-functionality, driving continuous development in drone technology.
Magnets Manufacturer
At Tengye, we’re thrilled to be early participants in your new projects. Our passion for magnets extends from material selection and design optimization to providing magnetic solutions. We hope to bring our knowledge and experience to the forefront by actively engaging in your upcoming projects. Work with our magnet experts to get the right magnet solution.
Image Source: Brushless & Getty & Moleymagneticsinc & Mpcomagnetics & Remoteflyer & Semanticscholar & Wikipedia
