Multibeam Laser Telemetry for Head Protection of Visually Impaired Individuals

For individuals with visual impairment, traditional long canes provide insufficient protection against hazards at torso or head height. While various Electronic Travel Aids (ETAs) have been developed as complementary tools, a fully reliable solution for head protection remains elusive. Existing technologies do not yet provide a reliable and robust sensing solution suitable for all environments and all obstacle types. To address these limitations, this study presents the design and preliminary validation of a proof-of-concept multibeam laser triangulation architecture intended for head-level obstacle detection. The device uses a near-infrared (850 nm) laser source, split into three beams via a holographic grating, and a CMOS camera equipped with interference filters for signal acquisition. The hardware architecture integrates an FPGA and a low-RAM microcontroller to minimize power consumption, facilitating its use as a portable embedded device. Preliminary controlled laboratory experiments were conducted to validate the performance of the detector under varied environmental conditions and during conventional white cane use. The objective is to evaluate the feasibility of this sensing strategy, how it can enhance user safety and identify the remaining challenges toward an operational device.