Table 1.

Advantages and disadvantages of different sensors for emotion recognition.

Sensors	Advantages	Disadvantages
Visual sensor	Simple data collection; high scalability	Restricted by light; easy to cause privacy leakage [26]
Audio sensor	Low cost; wide range of applications	Lack of robustness for complex sentiment analysis
Radar sensor	Remote monitoring of physiological signals	Radial movement may cause disturbance
Other physiological sensors	Ability to monitor physiological signals representing real emotion	Invasive, requires wearing close to the skin surface [27]
Multi-sensor fusion	Richer collected information; higher robustness	Multi-channel information needs to be synchronized; the follow-up calculation is relatively large