1 Introduction
2 UAV Background
2.1 UAV Definition
2.2 UAV Types
3 UAV Paper Identification Process
4 Perceptual Map of UAVs
4.1 The Four UAV Categories
4.2 Link with Previous Study
4.3 Research Efforts Towards Companion UAVs
5 From Remote-Controlled to Autonomous UAVs
5.1 Human Following UAVs
5.2 User Interfaces for UAVs
6 From Remote-Controlled to Social UAVs
7 Observation and Lessons Learned
8 Guidelines and Recommendations
9 Conclusion