China unveils system for stable supersonic electromagnetic launches

In 2023, China achieved a breakthrough with its large-scale electromagnetic launcher, known as the "electromagnetic sledge," which became the first of its kind to surpass the sound barrier by accelerating one-ton test vehicles beyond Mach 1. Operating for over two years in Jinan, this system overcame a critical challenge faced by previous attempts worldwide: the destructive sonic boom generated at ground level, which traditionally damaged sensors essential for speed and position monitoring. The intense shock waves at supersonic speeds disrupted conventional sensor-based control systems, making reliable supersonic electromagnetic launches difficult. To address this, researchers led by Xu Fei from the Chinese Academy of Sciences developed a novel sensorless speed estimation method. Instead of relying on vulnerable external sensors, their approach extracts velocity data from subtle voltage fluctuations within the launcher’s segmented electromagnetic coils. By analyzing and filtering these electrical signals through an advanced algorithm, the system achieves real-time, highly accurate speed tracking with an error margin as low as 1.1% at