This paper details the development of a control system for a Portable Powered Ankle-Foot Orthosis (PPAFO) aimed at improving mobility for individuals with motor disabilities in diverse outdoor environments. The system utilizes sensor data from an IMU and an ankle encoder to provide accurate task classification and dynamic ankle support. Key methods explored include the Zero Velocity Update (ZUPT) for precise foot movement detection, integration of accelerometer and gyroscope data for orientation estimation, and motion analysis of cyclic variables to map gait progression. Experimental tests on a treadmill with varying speeds and inclines demonstrate the system's efficacy. The paper also outlines future enhancements to the control system.