In the operation of new energy drones, the wiring harness bears the heavy responsibility of power transmission and signal interaction, and its electromagnetic shielding process is directly related to the stability of signal transmission.
In the new energy drone system, the generation and propagation mechanism of electromagnetic interference is the basis for understanding the problem. The power system, motor controller, battery and other components of the drone will generate high-frequency electromagnetic signals during operation. Taking the motor as an example, during its high-speed operation, the rapid change of current will generate harmonics, which radiate to the surrounding space in the form of electromagnetic waves. The flight control system and communication module of the drone rely on weak electrical signals to transmit instructions and data. When the wiring harness is subject to electromagnetic interference, the interference signal will be coupled into the wiring harness and superimposed on the original signal, resulting in signal distortion, bit error or even interruption. If the flight control signal transmission is unstable, the drone may have serious problems such as out-of-control flight attitude and route deviation.
The core role of the electromagnetic shielding process is to build a protective barrier to resist the influence of electromagnetic interference on signal transmission. By wrapping shielding materials such as metal woven mesh and metal foil on the outside of the new energy drone wiring harness, the external electromagnetic interference signal can be reflected or absorbed. When electromagnetic waves encounter the shielding layer, part of the energy is reflected back into space, and part of the energy is converted into heat energy and consumed inside the shielding material, thereby reducing the intensity of interference signals entering the wiring harness. In addition, a reasonable shielding grounding design is also crucial. It can guide the induced charge on the shielding layer in time to prevent the accumulation of charge and generate secondary interference, ensure that the shielding layer always plays an effective role, and create a stable electromagnetic environment for signal transmission.
Different electromagnetic shielding materials have significant differences in signal transmission stability. Metal braided mesh has good flexibility and processability, can tightly wrap the wiring harness, and has a good shielding effect on medium and low frequency electromagnetic interference. It is widely used in drone wiring harnesses. However, for high-frequency electromagnetic interference, its shielding effectiveness will be reduced. In contrast, metal foil has better conductivity and shielding performance, especially in the high frequency band, and can effectively shield high-frequency electromagnetic interference such as millimeter waves, but metal foil is brittle and is prone to damage in the use scenario of frequent vibration and bending of drones, affecting the shielding effect. In addition, new composite shielding materials are gradually emerging. They combine the advantages of multiple shielding materials. For example, conductive polymers are coated on the surface of the woven mesh, which can maintain flexibility and improve high-frequency shielding performance, providing a new direction for optimizing signal transmission stability.
The shielding structure design of the wire harness is a key link in improving the electromagnetic shielding effect. The integrity of the shielding layer is crucial. Any gaps and improper interface processing will become a breakthrough for electromagnetic interference. In practical applications, seamless connection processes such as welding and crimping are required to ensure the continuity of the shielding layer. Special treatment is required for branches and connectors of the wire harness, such as using a connector with a shielding function and connecting it closely to the shielding layer of the wire harness through a metal shell to form a complete shielding system. At the same time, reasonable planning of the wiring harness layout can also reduce the risk of electromagnetic interference, separate the power line and the signal line, avoid parallel routing, reduce electromagnetic coupling, and further ensure the stability of signal transmission.
The optimization of the grounding system has a decisive influence on the effect of the electromagnetic shielding process. Good grounding can provide a low-impedance path for the induced current on the shielding layer, allowing it to be quickly introduced into the earth. The choice of grounding method needs to be determined according to the structure and electromagnetic environment of the drone. Single-point grounding, multi-point grounding and mixed grounding each have their own advantages and disadvantages. Single-point grounding is suitable for low-frequency electromagnetic environments and can effectively avoid ground loop interference; multi-point grounding is more suitable for high-frequency electromagnetic environments, which can reduce ground impedance and improve shielding effectiveness. In new energy drones, a mixed grounding method is often used, combining the advantages of different grounding methods. At the same time, filter elements such as inductors and capacitors are added to the grounding path to suppress high-frequency noise, ensure that the grounding system can play a good role in different frequency bands, and enhance the electromagnetic shielding process's ability to ensure signal transmission stability.
Quality inspection and evaluation of electromagnetic shielding technology is an important part of ensuring its effectiveness. Professional testing equipment, such as spectrum analyzers and network analyzers, can quantitatively test the shielding effectiveness of wire harnesses in different electromagnetic environments. In a laboratory environment, simulate the electromagnetic interference scenarios that may be encountered during the actual operation of the drone, measure the attenuation of the signal before and after the wire harness is shielded, and determine whether the shielding process meets the standards. In addition, long-term reliability testing is required to install the shielded wire harness on the drone, conduct flight tests, monitor the stability of signal transmission under actual working conditions, and promptly discover potential problems and improve the process. At the same time, a complete quality inspection standard and process is established to strictly inspect the performance of shielding materials, the integrity of shielding structure, the reliability of grounding system, etc., to ensure that each new energy drone wiring harness can meet the requirements of signal transmission stability.
The electromagnetic shielding process of new energy drone wiring harness significantly affects the stability of signal transmission through the synergistic effects of material selection, structural design, grounding optimization and quality inspection. In the context of the continuous development of new energy drone technology, continuous exploration of more advanced shielding materials and processes, optimization of shielding system design, and strengthening of quality control are the key to ensuring the safe and stable operation of drones and promoting their widespread application in more fields.
