Development of an integrated sugarcane quality management system using combined use of optical sensors

2022年，我们在日本冲绳的Minamidaito岛进行了甘蔗生长或成熟阶段（2022年10 - 12月）的实验。利用便携式可见光-近红外光谱仪对甘蔗田甘蔗秸秆的糖品质和吸光度光谱进行了测定。此外，我们使用配备多光谱相机的无人机收集甘蔗叶片的多光谱图像。我们通过检查便携式Vis-NIR光谱仪测量的糖品质与植被指数之间的相关性来评估多光谱图像在估计糖品质方面的有效性。此外，我们研究了甘蔗皮对Minamidaito的影响（Jan-Mar 2023）。我们对不同产地、不同品种的正常甘蔗秸秆进行扫描，并对甘蔗秸秆进行去皮，收获后带回实验室进行糖质测量，并建立了新的校准模型。利用多元线性回归方法建立模型后，我们发现去皮后的甘蔗光谱比未去皮后的甘蔗光谱噪声更低，而未去皮后的甘蔗蜡噪声更高。结果表明，去皮甘蔗光谱模型比非去皮甘蔗光谱模型提供了更准确的结果，因为去皮甘蔗光谱模型中相关系数最高的前两个波长包含了900 ~ 910纳米的糖含量吸收带，而普通甘蔗秸秆光谱模型至少需要选择4个波长才能找到糖含量吸收带。

In 2022, we conducted experiments on Minamidaito Island in Okinawa, Japan during the growth or ripening stage of sugarcane (October-December 2022). We measured sugar quality and absorbance spectra of sugarcane stalks in the sugarcane field using a portable Vis-NIR spectrometer. Additionally, we collected multispectral images of sugarcane leaves using an unmanned aerial vehicle equipped with a multispectral camera. We evaluated the effectiveness of the multispectral images in estimating sugar quality by checking the correlation between sugar quality measured by the portable Vis-NIR spectrometer and vegetation indices.Furthermore, we investigated the effect of sugarcane skin on Minamidaito (Jan-Mar 2023). We scanned normal sugarcane stalks and peeled sugarcane stalks from different fields and varieties, then harvested the sugarcane and brought it back to the laboratory to measure sugar quality and develop a new calibration model. After developing models using the multiple linear regression method, we found that the peeled sugarcane spectra showed lower noise than the non-peeled spectra, which had higher noise caused by sugarcane wax. The results reveal that the peeled spectra model provides more accurate results than the non-peeled sugarcane spectra model, as the top two wavelengths with the highest correlation coefficient of the peeled sugarcane spectra model contain the sugar content absorption band (900-910 nanometers), whereas the normal sugarcane stalk spectra model had to select at least four wavelengths to find the sugar content absorption band.