An Indoor Positioning System Based on Piezoresistive Aerogel Sensor^*

As society and technology continue advancing., the need for precise positioning in various environments is also rising. Although satellite positioning systems and wireless signal-based positioning methods are widely used., they have limitations in specific scenarios and struggle to meet all positioning requirements. To address the challenge., this work introduces a new positioning system based on flexible sensor., and is independent of traditional motion tracking technologies such as global positioning system or vision-based motion tracking. The system combines a WPU/CNC/CNT flexible sensor and an inertial measurement unit (IMU). The flexible sensor estimates the step length., while the IMU records the heading angle. The experimental findings indicate that the flexible sensor has a relative error of 1.90% in length prediction., whereas the traditional acceleration-based method has a relative error of 6.49%. During parking lot test., the positioning error based on the flexible sensor is only 21.89 cm., while the positioning error based on the traditional method is 27.25 cm. This demonstrates that the trajectory prediction accuracy of the flexible sensor is significantly superior to the traditional positioning method. Flexible sensor can better conform to the skin's surface., not only eliminating wearing errors but also enhancing user comfort. Furthermore., this sensor demonstrates impressive stability during long-term use., addressing the drift issue common in other technologies over extended periods. In the future., combined with more advanced artificial intelligence models., flexible sensor has the potential to achieve independent positioning.