The passive operating mode of the linear optical gesture sensor

TL;DR

This paper evaluates the passive mode of a linear optical gesture sensor under natural light, proposing a classification criterion that achieves high accuracy in detecting gestures and ambient light conditions, while significantly reducing energy consumption.

Contribution

It introduces a new criterion for differentiating ambient light states and demonstrates the sensor's effective gesture detection in passive mode with low energy use.

Findings

Ambient light condition classifier accuracy: 85.15%

Gesture recognition accuracy in passive mode: 98.76%

Energy consumption reduced by 93.34% in passive mode

Abstract

The study evaluates the influence of natural light conditions on the effectiveness of the linear optical gesture sensor, working in the presence of ambient light only (passive mode). The orientations of the device in reference to the light source were modified in order to verify the sensitivity of the sensor. A criterion for the differentiation between two states: "possible gesture" and "no gesture" was proposed. Additionally, different light conditions and possible features were investigated, relevant for the decision of switching between the passive and active modes of the device. The criterion was evaluated based on the specificity and sensitivity analysis of the binary ambient light condition classifier. The elaborated classifier predicts ambient light conditions with the accuracy of 85.15%. Understanding the light conditions, the hand pose can be detected. The achieved accuracy of the hand poses classifier trained on the data obtained in the passive mode in favorable light conditions was 98.76%. It was also shown that the passive operating mode of the linear gesture sensor reduces the total energy consumption by 93.34%, resulting in 0.132 mA. It was concluded that optical linear sensor could be efficiently used in various lighting conditions.