Study Of Characteristics On Plant Electricity Under Controllable Environment

The plant electrical signal is the resting potential of tissues and cells, when under the stimulation of the external environment. It can be used to characterize plant physiological processes and plant physiological signals. Its characteristic is weak and low frequency, amplitude in a few tens of microvolts and most of the frequency is less than 5Hz. Because of the noise of the test site and the mutual interference of various kinds of signals in the plant, they will have a serious impact on the electrical signal. Therefore, it is necessary to use effective pretreatment methods, to be able to carry out an accurate interpretation of the plant electrical signalsThis study first uses the plant electrical signal acquisition platform to collect the signal of Swallow palm and Sansevieria, and to denoise the collected plant electrical signal. Compared three denoising analysis, wavelet hard threshold denoising, wavelet soft threshold denoising and unbiased risk estimation denoising, By comparing the effect of noise elimination and the value of SNR, the research finally uses wavelet soft threshold denoising method to eliminate the noise of the signal.The analysis algorithm includes three kinds, first is time domain analysis, Statistic and analysis characteristic value of Mean value, peak value, variance and mean square deviation; second, frequency domain analysis, the AR power spectrum analysis method was used to deal with the plant electrical signal, the energy distribution of the signal is analyzed by the power spectrum curve, And through the three parameters values of edge frequency, gravity frequency and power spectral entropy, comprehensive analysis of frequency domain characteristics of plant electrical signals; Third, time and frequency analysis method, compared with the Wavelet time frequency analysis and short time Fourier analysis, at the same time, In order to make up for the deficiency of these two methods, using db5 wavelet with five scales decomposition.Respectively changing the LED light intensity, ambient temperature and soil moisture of the plant growth cabinet. By collecting the swallow palm and Sansevieria in plant electrical stimulation of different environmental factors, Using time domain, frequency domain and time frequency domain algorithm to processing and analyzing, combined with the growth characteristics of the two kinds of plants, it was concluded that the most suitable LED light illumination, ambient temperature and soil moisture of the two kinds of plants. The optimum illumination of Swallow palm is 15~22klux, the optimum ambient temperature is 25.5℃, the optimum soil moisture is 11.2%~24.9%. The optimum illumination of Sansevieria is 21~28klux, the optimum ambient temperature is 30.5℃, the optimum soil moisture is 11.2%~18.4%.