Systems and methods for in situ gap inspection in a machine, such as a generator, an electric motor, or a turbomachine are described. A robotic crawler has multidirectional traction modules, an expandable body, and sensor modules. A control system communicates with the robotic crawler to provide a control signal to navigate an inspection path within an annular gap of the machine. The inspection path includes axial and radial movements to inspect the annular gap using the sensor modules.