Design Of Stereo Light-supply Control System Based On The Differential Light Requirement Characteristics Of Cucumber Plants

Light is the primary condition for photosynthesis of plants.However,in recent years,the lack of illumination in the facilities has seriously restricted the growth of facility crops due to the haze weather.In order to increase production and quality of facility agriculture in winter and spring,it is necessary to use artificial light supplementation.In the traditional light-supply mode,the filling-light is suspended at the top of the greenhouse,which results in the photosynthetic capacity of the plant declining due to the photoinhibition of the functional leaf position at the top of plant and the insufficient illumination of the lower and middle leaves of plant.Based on previous studies,it is known that there are significant differences in light requirements between different leaf positions of cucumber plants,but the existing plant filling-light technology does not take this into account,and thus the amount of light supplementation does not match the actual plant demand.Considering the shortcomings of the existing plant light-supply technology,this paper developed a stereo light-supply control system based on the differential light requirement characteristics of cucumber plants.The control system can realize the acquisition of different leaf position environmental information in the facility greenhouse,the adjustment of the stereo filling-light suspension position,and the dynamic feedback adjustment of the supplementary quantity of the filling-light.Finally,the optimal control of light environment in facilities is realized to improve the yield and quality of cucumber in facilities.The main research contents and conclusions of this paper are as follows:Research and development of lifting mechanism of filling-light based on Arduino control.Considering the difficulty in adjusting the suspension height and affecting the agricultural activities during the application of the stereo filling-light,a lifting mechanism capable of automatically measuring the distance and accurately adjusting the suspension position of the filling-light has been developed.The lifting mechanism receives the lifting command through the CC2530 module,the TFmini laser radar automatically measures the distance,and the TB6600 drives the 57 stepping motor.The Arduino development board realizes the control of the lifting mechanism through the lifting control program.Finally,the driving shaft rotates and wraps the flexible steel wire to realize accurate adjustment of suspension position of the filling-light.Research and development of light-supplementing node and monitoring node of stereo filling-light control system.Considering the differential characteristics of light demand of plant leaf position and the manufacturing cost of LED filling-light,a lamp-type filling-light with adjustablele lamp spacing and dynamic feedback correction of light-supply value was developed.The filling-light includes 3 red tubes and 2 blue tubes,red tube narrow-band aluminum substrate for welding 14 plant red LEDs,blue tube for welding 10 plant blue LEDs,to achieve filling-light red and blue light ratio 2:1.The CC2530 module receives and parses the command to generate the PWM signal,and the drive circuit realizes the brightness control of the filling-light.The monitoring node is completed on the basis of the existing monitoring equipment in the laboratory,and can obtain environmental information of different leaf positions in the facility.Research and development of intelligent light-supply control terminal based on Raspberry Pi.Considering the multi-faceted requirements of the stereo light-supply control system,an intelligent control terminal capable of processing environmental data in the facility,controlling the precise operation of the lifting mechanism,and dynamic feedback adjustment of the supplementary quantity of the filling-light was developed.The control terminal uses the Raspberry Pi as the hardware development core,the touch screen display realizes human-computer interaction,and the CC2530 module establishes the Zigbee wireless network.The human-computer interaction interface of the control terminal is developed under the software of PyQt5,and the main program of the control system is written by Python language.Optimal control of light environment in facilities can be realized by control terminal controls the monitoring,light-supply and lifting nodes.Performance testing and control effect verification of stereo light-supply control System.Performance test includes filling-light field experiment and control accuracy test of lifting mechanism.The light intensity and effective light coverage of 20cm position of filling-light are the best.The average relative error of response of lifting mechanism is1.06%,which meets the practical application requirements.Through the comparative experiment of light-supply effect in demonstration base of vegetable industry comprehensive service zone in Jingyang county,Shanxi Province,it was concluded that the cucumber plant height and stem diameter increased significantly in stereo light-supply area compared with traditional light supplement area and natural treatment area,Compared with the natural treatment area,the average plant height and stem diameter increased by 26.51%and 36.03%respectively.By comparing the photosynthetic rate at the same leaf position,cucumber plants in the stereo light-supply area grew stronger and had stronger photosynthetic capacity.Compared with the natural treatment area,the output of the stereo light-supply area increased by 1.39 kg/m~2 and the economic benefit increased by 4.87RMB/m~2 in one month's harvesting period.Therefore,the stereo light-supply control system has a good light environment optimization effect.