Safety-Centric Layered Architecture for a Biped Exoskeleton

Lower-limb exoskeletons integrate mechanical, elec trical, and software technologies to enable interaction with the external environment in a safety-critical context. These systems require real-time response, functional safety, and scalability. This paper introduces a layered sensor-actuator abstraction designed to decouple hardware-dependent services from high-level gait control logic. The proposed architecture comprises four layers: Microcontroller Abstraction (MCAL), Electronic Component Abstraction (ECAL), generic services, and the application layer. It incorporates a dual-tier diagnostic and graded protection mechanisms, achieving deterministic sensor-to-actuator latency. This approach facilitates rapid feature iteration, supports pre dictive torque assistance, and enables cloud-based rehabilitation analytics, adhering to ISO 13482 and IEC 61508 safety standards.