Chapter 7: Health Management and Safety Assessment
Intelligent unmanned systems are typical complex systems. "Complex systems" generally refer to systems with large scale, complex structure, diverse functions, numerous failure modes, and unknown/variable external environments, often exhibiting characteristics such as nonlinearity, dynamic variability, large scale, multiple levels, and decentralization. Examples include the human body, various vehicle systems, precision CNC machines, and other mechanical or electrical systems. As system complexity increases, the number of components and failure probability also increase. Reducing the probability and consequences of failure is the focus of system health and safety assessment.
Any unmanned system can be decomposed into several components (or subsystems), including physical components (motors, propellers, gyroscopes) and virtual components (wind, air pressure, obstacles). Each component can be considered to contain three types of models: energy consumption model, motion model, and fault model. The motion model describes the component's transient behavior, the energy consumption model describes long-term state behavior, and together they describe the component's normal short-term and long-term operation. The fault model describes deviation from normal operation due to various internal and external factors.
Airframe faults can be classified into propulsion system faults, energy system faults, sensor faults, structural faults, and control system faults based on subsystem topology and fault types.
The definition of safety for unmanned systems differs significantly from manned systems. The RflySim Toolchain's approach starts with offline evaluation: establishing a preliminary Failure Mode and Effects Analysis (FMEA) table and historical database. Next, real-time online evaluation is conducted using offline evaluation outputs. After each flight mission, real-time data is collected, health indicators and safety status of each subsystem are updated, and the FMEA table and historical database are refreshed — creating an iterative offline-to-online evaluation cycle.
Session 6: Health Management and Safety Assessment (Part 1)
Session 6: Health Management and Safety Assessment (Part 2)
Session 6: Health Management and Safety Assessment (Part 3)