No clear distinction / boundary between navigable and non-navigable region.
Partial occlusion due to traffic / pedestrians.
Other dynamic patterns like shadows etc.
Variety of lighting conditions - morning, afternoon, evening, cloudy, sunny
Approach:
Direct mapping from RGB images to control output using Convolutional Neural Networks (CNN).
Simplified the output space into three control signals:
Move Straight
Turn Left
Turn Right
Reference: Giusti, Alessandro, et al. "A machine learning approach to visual perception of forest trails for mobile robots." IEEE Robotics and Automation Letters 1.2 (2016): 661-667.