Water Level Recognition by Analyzing the Sound when Pouring Water

In our daily lives, we often pour liquids into containers, and it can be challenging to accurately gauge the liquid level in opaque, narrow-mouthed containers. Visual inspection is not always reliable and can lead to spillage. Using a liquid-level sensor is one option, but it requires attaching a device to each container, which is complicated. We propose a method that uses sound to estimate the water level inside a container. This method is versatile and does not require installing a device for each container. We conducted evaluation experiments, and the results showed that the estimation accuracy averaged 0.462 for bottle-dependent and 0.308 for bottle-independent estimation models when estimating water levels from 0% to 100% in 10% increments. Additionally, the average estimation accuracy for determining whether the water level is above 90% was 0.744, even when using a bottle-independent estimation model. These results suggest that while there is room for improvement in the estimation accuracy, the proposed method has potential applications in natural environments for overflow detection. In the future, we plan to develop a faucet-mounted device with a function to stop water pouring just before the container fills up.