Detection And Analysis Of Plant Stem Status In Plant Growth Based On Ultrasonic Radio Frequency

Detection of stem status is an important part of plant growth detection.In recent years,progress has been made in the detection of plant stem status at all levels..It is clear that there is a close relationship between the dynamic change of water in stem and the structure of stem.Modern plant stem detection needs not only to detect the dynamics of water changes,but also to detect differences in stem structure.In order to explore the dynamic detection of water status with structural characteristics of stems,this paper presented a method,ultrasonic radio frequency,for the detection of the plant status.Multiple plant stems in multiple periods were set as detection objects.The ultrasonic performance of growth regulation of the plant stem was studied,from the change of the stem water and the structure difference,with the multiple features of the ultrasonic radio frequency(RFID).The main research and conclusion were listed here.(1)The detection mechanism of plant stem status based on ultrasonic radio frequency was established.Based on the moisture content of stem in plant growth,this mechanism was established by comparative analysis of ultrasonic propagation in industrial ultrasonic inspection,in medical ultrasonic testing and in stem ultrasonic testing.At the same time,the paper designed and realized an ultrasonic radio frequency detection platform for plant stems,because there was no such kind of detection equipment.(2)An algorithm was proposed to accurately automatically extract the primary echo position information of the ultrasonic wave in the plant stem.Because the ultrasonic wave would be reflected many times with the strong attenuation in the plant stem,the traditional AIC algorithm cannot be used to determine the primary echo position,which would affect the ultrasonic velocity in plant stem.An improved algorithm,named hybrid differential AIC,was proposed by this paper to accurately detect the position of the ultrasonic primary echo in plant stems,which was a key parameter in our study.(3)The ultrasonic radio frequency performances of the structural differences of the stem were compared.According to the structure difference of plant stem,the ultrasonic tests of the stem anisotropy and the variety of stem species were designed.The ultrasonic data of stem was obtained in time domain,frequency domain and time-frequency domain.About 20 features were extracted which were selected by information gain method and self-evaluation method.The analysis of the heterosexual and interspecific characteristics of the plant stems from the above characteristics has been analyzed.It showed that ultrasonic radiofrequency could be used as an effective means to detect the structural differences of plant stems.(4)The performance of the changes of water content in plant stems by ultrasonic features had explored.On the basis of the water content,the key index of plant stem status,the ultrasonic performance of the change of stem water was studied,which was focused on the sensitivity of ultrasonic signal to the changes of water content in vitro and in vivo stems respectively from the ultrasonic velocity,energy and frequency features of the ultrasonic signal in plant stems.It showed that ultrasonic radiofrequency could be used as an effective means to detect the changes of water content of plant stems.(5)The ultrasonic performance of plant stem status under short time scale and long time scale is studied.The ultrasound characteristics of diurnal and seasonal variation of plant stems of woody and herbaceous were explored from multi ultrasonic features.It was found that the variance of the ultrasonic features of the stem in daytime accord with the plant growth.There was a significant seasonal variation in the ultrasonic features of stems in the long time scale,which was in line with the rule of the plant growth,slow in winter and active in winter.Finally,Detection method for plant stem status was fulfilled based on the ultrasonic radio frequency which was nondestructive,on-line,and could reflect the structure of the stem.To sum up,the ultrasonic radio frequency technology can realize nondestructive on-line detection of plant stem status in plant growth with characteristic of stem structure.