Research And Application Of Plant Electrical Signal Online Detection Equipment

Plant electrical signal is a kind of physiological signal which plays an important role in the information transmission between plant tissues.It can reflect the growth and development of higher plants and the changes of nutritional status and external environment.The research on the acquisition equipment of plant electrical signal and the time-frequency characteristics of electrical signal will lay a foundation for the establishment of the model of the follow-up plant electrical signal and environmental factors,which is of great significance for the construction of the intelligent control system of crop electrical signal to realize the automatic production of crops.First,according to the characteristics of plant electrical signal,a set of on-line detection equipment of plant electrical signal is designed and developed.Then,the reliability and stability of the equipment are verified by the coefficient of variation and Pearson correlation coefficient.Finally,the equipment is used to collect electrical signals of aloe and Hedysarum chinense under different light intensity and soil humidity.The time-domain,frequency-domain and time-frequency-domain correlation signal processing algorithms are used to analyze the characteristics of the electrical signals collected in the experiment,and the effects of these two environmental changes on the electrical signals of the two plants are studied.The main research results are as follows:(1)According to the three basic characteristics of plant electrical signal,which are weak,low frequency and time-varying,a set of plant electrical signal online detection equipment is designed and developed.After experimental analysis and equipment debugging,the equipment can successfully collect plant electrical signals;(2)Using Butterworth filter,adaptive power frequency filter and wavelet threshold denoising to preprocess the collected electrical signal;using time-domain analysis method,statistical peak value and mean value of plant electrical signal,using frequency-domain analysis method(AR power spectrum estimation),generating power spectrum with power rate varying with frequency;because wavelet has the advantage of variable time-frequency resolution more It is suitable for the analysis of plant electrical signals,so we use wavelet transform to do time-frequency analysis of plant electrical signals;(3)The electrical signals of plants with different soil moisture and different light intensity were collected by the acquisition system,and analyzed by the time-domain,frequency-domain and time-frequency-domain analysis algorithm to get the change trend of electrical signals when the environment changes.The experiment shows that the on-line detection equipment of plant electrical signal can collect electrical signal successfully.