This paper introduces a real-time gait phase detection system and algorithm utilizing non-contact distance sensing, specifically designed for wearable robotic applications. Two Time-of-Flight (ToF) sensors are positioned on the outer heel and the fifth metatarsophalangeal (MTP) joint to monitor foot-to-ground distance throughout the gait cycle. These sensors are housed in overshoe-type modules to minimize interference with natural walking and allow for easy attachment to various types of footwear. The proposed method segments gait phases using a lightweight, thresholdbased algorithm that is both computationally efficient and physically interpretable. Experimental validation with a healthy subject shows that the system reliably detects stance and swing phases, producing temporal patterns that are comparable to those of conventional pressure-based systems. Importantly, the system provides continuous data even during swing phases, facilitating smoother transitions for control systems. The simplicity and wearability of the hardware indicate its potential for real-time control in lower-limb wearable robots, gait assistance devices, and ambulatory monitoring systems.
