Multi-machine collaboration realization conditions and precise and efficient production mode of intelligent agricultural machinery

Multi-machine collaboration of agricultural machinery is one of the international frontier and hot research in the field of agricultural equipment.However,the current domestic multi-machine collaborative operation of agricultural machinery is limited to the research of task goal planning and collaborative path optimization in a single production link.In order to achieve the purpose of zero inventory of agricultural materials and precise and efficient production operations,a new technology of agricultural machinery multi-machine collaboration with multi-dimension and full chain was proposed,which takes into account the whole process of agricultural production,as well as agricultural machinery system and external supply chain,storage and transportation chain collaboration.The problems of data collaboration,process collaboration and organization collaboration were analyzed.And the realization conditions of new multi-machine cooperative technology were analyzed.Meanwhile,the zero inventory mode and precise operation mode of agricultural materials under the background of multi-machine cooperation of intelligent agricultural machinery were studied.Then,a precise and efficient agricultural production mode based on data-process-organization collaboration was constructed.The results showed that the multi-machine cooperative technology mode of multi-dimensional and full-chain agricultural machinery could greatly improve the efficiency of agricultural machinery,operation quality,land utilization rate and reduce production cost.

Optimized design and test for a pendulum suspension of the crop spray boom in dynamic conditions based on a six DOF motion simulator

Spray deposit distribution from a field sprayer is mainly affected by the boom movements when the tractor is driven over a rough soil surface,the pendulum suspension that used to reduce and control the movement of spray boom by isolating the boom from vibrations of the tractor will directly enhance uniform deposition of chemicals.However,how to match the parameters of the suspension with the properties of the boom is the key problem.The dynamic rigid-flexible coupling model of the virtual prototype of the spray boom suspension system was established by using ADAMS and ABAQUS software.An optimization of the suspension parameters for a large spay boom was carried out based on the optimal Latin hypercube design,radial basis function neural network,and multi-objective genetic algorithm NSGA-II.After modified parameters of the suspension,the travel of the sprayer on a typical field motion track was simulated based on a six DOF motion simulator,and the dynamic behavior of the boom suspension was measured.The results show that RMS of the measured boom roll angle and the boom center displacement for optimized solution were reduced by 14.76%and 12.43%compared with the original suspension.Finally,the inertial measurement unit(IMU)was used to measure the movements of the sprayer vehicle during the pesticide application on the Hongze Lake Farm,the experiment of field condition reproduced by using the six DOF motion simulator,the standard deviation of the roll angle and vibration displacement for the optimized sprayer boom are only 0.6382°and 62.279 mm respectively.The research provides theoretical basis and experimental method for parameter optimization of large scale boom suspension.

Nondestructive diagnostics of soluble sugar,total nitrogen and their ratio of tomato leaves in greenhouse by polarized spectra-hyperspectral data fusion

Polarized spectra-hyperspectral data fusion technique was used to estimate the soluble sugar(SS),total nitrogen(N),and their ratio(SS/N),of greenhouse tomato leaves.Fresh tomato leaves of five different growth stages(seedling,flowering,initial fruiting,mid-fruiting and picking stage)and five different nitrogen treatments(severe stress 25%,moderate stress 50%,mild stress 75%,normal 100%,and excess 150%)at every stage were collected for spectra acquisition and SS and N determination.Polarized reflectance spectra were acquired with a polarization reflectance spectrum spectro-goniophotometer system and four polarization degree features were extracted.Hyperspectral data were collected with a hyperspectral imaging system and four reflectance spectrum features and eight image features were extracted.Initially,models were built with polarization degree features,image features,and spectral features respectively.Linear and nonlinear fusion methods were comparatively used for modeling based on normalized data of the three sources.The results suggest that the performances of SS/N models are better than those of N and SS models,and the prediction capability of the Support Vector Machine(SVM)models of N and SS/N are superior to those obtained with single kind feature.This work indicates that the polarized spectrum-hyperspectral multidimensional information detecting method can feasibly judge the tomato nutrient stress conditions.Multi-features data fusion analysis technique can enhance the prediction accuracy of spectral diagnostics technology in precision agriculture.

Design and experiment of electro hydraulic active suspension for controlling the rolling motion of spray boom

Boom sprayer is one of the most commonly used plant protection machinery for spraying pesticide.Studies have shown that the efficiency of chemicals is highly correlated with the uniformity of spray distribution patterns.As the boom is a large and flexible structure,boom rolling leads to overlapping and leakage of the pesticides.In order to improve spray uniformity,the boom attitude should be kept parallel to the ground slope or to the crop canopy beneath the boom.Passive suspension can attenuate frequencies above its resonance frequency,but nothing can be done to align the boom to the sloping ground.Therefore,an active suspension system is designed,which includes DSP-based controller,a servo valve,a hydraulic cylinder,two ultrasonic sensors,one inertial attitude sensor,and the developed control procedures.In order to prevent the wrong response of the control system caused by the high frequency component due to uneven crop canopy or rough ground.A special signal processing algorithm was proposed,including the limiting filter,smoothing algorithm and data fusion algorithm based on optimal weight.The transient and steady-state performances of the boom control system using velocity feedforward PID algorithm were tested on a six DOF motion simulator.It can be seen that the low-frequency tracking performance of the boom was greatly improved after the electro-hydraulic active suspension was added.At the resonance frequency,the peak angle of active suspension and passive suspensions are 0.72°and 1.29°respectively,and the resonance peak is greatly reduced.The controller was implemented on a self-propelled boom sprayer and validated under field conditions,the standard deviation of the roll angle of the boom with active suspension is 0.40°,compared with 1.04°of the sprayer chassis.Experimental results show that the active suspension control system can effectively reduce the effect of ground excitation disturbance on the application process,and has good tracking performance for low frequency terrain change.

Effects of daily light integral on tomato(Solanum lycopersicon L.)grafting and quality in a controlled environment

As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of vascular tissue in grafted seedlings.The effect of daily light integral(DLI)on the healing process and seedling quality of tomato(Solanum lycopersicum L.)was analyzed in this study,with the comparison of grafted seedlings treated in dark for 7 d after grafting.The results showed that the height increment of scion and rootstock,adhesion of graft union,stem flow,total chlorophyll content,and net photosynthesis rate increased gradually with increasing light intensity,and no longer increased significantly when the DLI was higher than 5.04 mol/m^(2)·d.The contents of auxin(IAA)and gibberellin(GA)in tomato leaves increased and abscisic acid(ABA)decreased with the increase of DLI.However,there was no significant difference between the treatments with DLI higher than 6.48 mol/m^(2)·d.Both the biomass and energy use efficiency(EUE)of grafted seedlings increased with DLI in a certain range and then decreased.The biomass was the largest when DLI was 5.04 mol/m^(2)·d.However,EUE was highest when DLI was 7.46 mol/m^(2)·d.In conclusion,a suitable DLI is beneficial to cultivate high-quality grafted tomato seedlings,and increasing DLI within a certain range can promote biomass accumulation,connection of vascular tissue,and endogenous hormone biosynthesis in tomato grafted seedlings during the healing period.The lighting environment with DLI of 5.04 mol/m^(2)·d(light intensity of 100μmol/m^(2)·s and light time of 14 h/d)is recommended for the healing treatment in high-quality production,which also improves EUE during the healing period of tomato grafted seedlings.

Separation-enrichment method for airborne disease spores based on microfluidic chip

Airborne diseases are likely to cause crop yield reduction,which has aroused widespread concern.In this study,a two-stage separation-enrichment structure microfluidic chip with a compound field for separation and enrichment of the greenhouse crops airborne disease spores directly from gas flow was developed.The chip is mainly composed of three parts:arc structure pretreatment channel,semicircular electrode structure and collection tank.COMSOL 5.1 software was used to simulate the designed microfluidic chip.30μm particles were used to represent P.xanthii spores,25μm particles were used to represent P.cubensis spores,and 16μm particles were used to represent B.cinerea spores.The simulation results showed that the separation and enrichment efficiency of 16μm particles,25μm particles,and 30μm particles was 88%,91%,and 94%,respectively.The experimental verification results were observed under a microscope.The results showed that the separation and enrichment efficiency of B.cinereal spores,P.cubensis spores and P.xanthii spores was 75.7%,83.8%and 89.4%,respectively.As a result,the designed microfluidic chip can be used to separate and enrich the spores of airborne diseases of greenhouse crops,which can provide a basis for the research of real-time monitoring technology for greenhouse airborne diseases.

Recognition of weeds at asparagus fields using multi-feature fusion and backpropagation neural network

In order to solve the problem of low recognition rates of weeds by a single feature,a method was proposed in this study to identify weeds in Asparagus(Asparagus officinalis L.)field using multi-feature fusion and backpropagation neural network(BPNN).A total of 382 images of weeds competing with asparagus growth were collected,including 135 of Cirsium arvense(L.)Scop.,138 of Conyza sumatrensis(Retz.)E.Walker,and 109 of Calystegia hederacea Wall.The grayscale images were extracted from the RGB images of weeds using the 2G-R-B factor.Threshold segmentation of the grayscale image of weeds was applied using Otsu method.Then the internal holes of the leaves were filled through the expansion and corrosion morphological operations,and other interference targets were removed to obtain the binary image.The foreground image was obtained by masking the binary image and the RGB image.Then,the color moment algorithm was used to extract weeds color feature,the gray level co-occurrence matrix and the Local Binary Pattern(LBP)algorithm was used to extract weeds texture features,and seven Hu invariant moment features and the roundness and slenderness ratio of weeds were extracted as their shape features.According to the shape,color,texture,and fusion features of the test samples,a weed identification model was built.The test results showed that the recognition rate of Cirsium arvense(L.)Scop.,Calystegia hederacea Wall.and Conyza sumatrensis(Retz.)E.Walker were 82.72%(color feature),72.41%(shape feature),86.73%(texture feature)and 93.51%(fusion feature),respectively.Therefore,this method can provide a reference for the study of weeds identification in the asparagus field.

Opposing effects of plant growth regulators via clonal integration on apical and basal performance in alligator weed

Invasive plants are a major threat to biodiversity and may adversely affect food security.Clonal integration enables the sharing of resources between connected ramets and can enhance plant performance in many invasive species.However,few studies have examined the role of clonal integration when weeds are exposed to plant growth regulators(PGRs).PGRs are used extensively in agriculture and may affect nearby weeds through soil leaching,erosion and runoff.Our aim was to investigate the effects of clonal integration on growth in a noxious weed,Alternanthera philoxeroides(alligator weed),in response to two PGRs frequently used in agriculture,gibberellins(GAs)and paclobutrazol(PAC).Ramets of A.philoxeroides were propagated in the greenhouse,and treated with PGRs.PGRs were applied to the older ramets(i.e.‘basal’part),with half of the plants having the stems between the apical(younger)and basal parts left connected,while the remaining plants had the stems between the two parts severed.Following the growing period,plants were measured for growth traits.We found that GA and PAC had contrasting effects on plant growth.GA significantly promoted above-ground growth of the apical ramets via clonal integration.Alternatively,PAC inhibited above-ground growth in the basal and apical parts,and enhanced below-ground growth of the basal and apical ramets through clonal integration.Our results highlight how clonal integration can promote growth in A.philoxeroides following the application of PGRs,which is likely an important mechanism for this species to invade new environments.

Effects of nutrient solution irrigation quantity and powdery mildew infection on the growth and physiological parameters of greenhouse cucumbers

For important economic crops such as cucumbers,abiotic and biotic stress conditions have had an adverse effect.This study aimed to observe the effects of water stress and powdery mildew stress on cucumber plants.Biotic stress at two levels,B0(no powdery mildew stress)and B1(powdery mildew stress)with three fertigation requirement levels(T1:Full fertigation,T2:Moderate nutrient solution deficit,T3:Severe nutrient solution deficit).Therefore,set up six treatments of B0T1,B1T2,B0T3,B1T1,B1T2,and B1T3.Leaf gas-exchange parameter first decreases and then increases under B1T1,B1T2,and B1T2.The leaf gas exchange parameter was significantly decreased under B0T2 and B0T3.Compared to the control experiment(CK,B0T1:no disease infestation and full irrigation),the plant height of cucumber decreased by 7.55%,10.62%,15.28%,23.27%,and 35.16%,respectively,under B0T2,B0T3,B1T1,B1T2 and B1T3;the stem diameter of cucumber decreased by 9.46%,15.74%,5.47%,13.45%,and 23.72%,respectively,under B0T2,B0T3,B1T1,B1T2,and B1T3;the leaf area of cucumber decreased by 13.76%,29.96%,13.43%,38.21%,and 66.83%,respectively,under B0T2,B0T3,B1T1,B1T2,and B1T3.The root-shoot ratio of cucumber was 3.92%,3.13%,3.63%,3.84%,4.41%,and 3.82%,respectively,under the B0T1,B0T2,B0T3,B1T1,B1T2,and B1T3.Therefore,this study can provide a basis for the research on greenhouse environmental control and cucumber cultivation management.

Highly sensitive detection of daminozide using terahertz metamaterial sensors

In order to solve the problems of low sensitivity and complex sample pretreatment in traditional detection,a method was proposed in this study to detect daminozide using terahertz combined with a metamaterial sensor,which enables real-time and label-free molecular detection with high sensitivity.The correlation between the transmission frequency shift and absorbance of daminozide solution at different concentrations was analyzed.The simulation and experimental results showed that this metamaterial sensor could achieve highly sensitive sensing of daminozide solutions at 0.05 mg/L.The maximum quality factor(Q_(max))of the two peaks could reach 5.78 and 13.05,and the maximum figure of merit(FOM)of the two peaks can reach 0.82 and 1.72.The maximum sensitivity of two resonance peaks reached 38.148 GHz/(mg·L)and 133.516 GHz/(mg·L)when the concentration of daminozide in the solution was 2000 mg/L.There was an obvious positive correlation between the transmission and transmission,frequency shift and frequency shift,and absorbance and absorbance of the resonance peak of daminozide solutions.Therefore,this platform not only opens up new possibilities for the microanalysis of the chemical composition of substances in solutions but also provides a valuable reference for the design of other metamaterial-based sensors in the field of food safety.

CFD simulation of sucrose flow field in the stem of greenhouse tomato seedling

Sucrose is the main constituent of assimilation transport from source to sink.In order to study the transport mechanism of sucrose,the sucrose at stem was taken as a research object and the sucrose flow field in tomato stem was analyzed using CFD ANSYS FLUENT simulation.The results showed that the sucrose pressure distribution was lower at bottom node and higher at middle node.The velocity of sucrose at different nodes was higher at the bottom node and lower at middle node and assimilation flow direction of the first,second,and third leaf from the bottom was towards the roots.The result of verification experiment showed that sucrose content measured at different nodes was higher at middle node than that of bottom node.Results of this study confirmed that ANASYS FLUENT can better simulate sucrose migration in greenhouse tomato stem.This study provides a new method for studying the partitioning mechanism of tomato assimilates in greenhouse.