Photonic integrated circuit-based force monitoring system for robotic wrists

A robotic wrist force monitoring system based on a photonic integrated circuit is proposed and experimentally demonstrated to address the limitations of conventional electrical force sensing schemes, including restricted installation space, poor electromagnetic immunity, and limited dynamic response. The system employs a distributed feedback laser array utilizing reconstruction-equivalent-chirp technique as a fast wavelength-tunable optical source. A high-speed driving and demodulation module based on field-programmable gate array is developed to enable precise wavelength control and real-time data processing. Combined with a self-designed force sensor and a fiber Bragg grating array, the system achieves high-sensitivity wavelength–force signal conversion and multi-channel parallel demodulation. The compact and lightweight demodulator can be embedded within robotic structures, featuring a fast demodulation rate and low measurement error. Experimental results show that the system achieves force recognition accuracy exceeding 0.22N with a sampling rate of 1kHz, while maintaining excellent stability and repeatability. The proposed system demonstrates superior performance in terms of real-time operation, precision, and anti-interference capability, providing an engineering-feasible photonic integrated solution for next-generation robotic force sensing and feedback control.