Research On Intelligent Control And Warning System Of Crawler Sprayer

Agricultural machinery automation and automatic early warning are important parts of the development of intelligent agricultural machinery.Through the analysis and research on the domestic and foreign information about the intelligence of agricultural machinery,this paper proposed to take the crawler sprayer as the research object,based on the PLC controller to study the three aspects of the sprayer's target spray function,crawler release warning function and the service life warning function of key components.The hardware selection and software programming of the control system was studied and analyzed,and the sprayer test on the basis of building the control system was carried out.This paper discussed the spray effect of target spray function and the utilization rate of pesticide,analyzed the critical condition value of track release warning and the reliability of the warning system for the service life of key components.In addition,it can realize accurate target targeting,low-dose spraying,caterpillar track loosening warning and service life warning of key components of the sprayer,and provide research reference for the development of intelligent agricultural machinery.Firstly,the target spray function is completed by PLC,laser ranging sensor and water flow detection sensor.The laser ranging sensor is used to detect the distance from the sprayer to the plant target and feed back to the PLC controller.PLC controller was used to analyze the distance value of the sprayer from the laser range sensor feedback to the plant target,and decide whether the sprayer head should open the spray action.The PLC controller was connected with the liquid flow monitoring sensor through RS485,and the liquid flow monitoring sensor was read and displayed from time to time.So the target spraying of the sprayer can be realized and the utilization rate of the pesticide can be calculated.Secondly,the warning function of track loosens depended on PLC,opto-electronic sensor and color standard sensor.The PLC controller indirectly calculated the speed of the driving wheel according to the response times received by the photoelectric sensor signal,the time interval corresponding to the adjacent two responses,and the arc length of the driving wheel walking on the mounting plane of the photoelectric sensor.Similarly,the PLC controller received the response times of the color code sensor,the corresponding time interval between two adjacent responses and the walking length of the track,and indirectly calculates the track speed.The PLC controller analyzed the measured driving wheel speed of the sprayer,the walking speed of the track and the functional relationship between them,and judged the warning value of the track loosening.Again,the key parts of the service life warning was the PLC controller sprayer nozzle solenoid valve,cylinder,valve,air pump,battery and other key parts of the number of times or time of cumulative statistics.Then,the accumulative use times or time of the key components recorded by the PLC controller were compared with the corresponding early-warning setting value in real time.When the parameters reach the early-warning value,the operator would be prompted to carry out maintenance or replacement.Finally,on the basis of setting up the control system,the actual machine test of the sprayer was carried out.Under the condition of continuous spraying by the sprayer,the average fog drop coverage rate of the canopy was 65.96%,and the average fog drop coverage rate among the trees was 66.29%.When the laser ranging sensor group and the sprinkler head group were installed in the same plane and the laser ranging sensor was enabled,the average fog drop coverage rate at the edge of the tree canopy was 37.23%,and the average fog drop coverage rate between trees was 16.61%.When the plane interval between the laser ranging sensor group and the sprinkler head group wasL₁ and the laser ranging sensor was enabled,the average fog drop coverage rate at the edge of the tree canopy was 53.88%and the average fog drop coverage rate between trees was 11.37%.The interval between the laser ranging sensor group and the sprinkler head group was set.When the laser ranging sensor and the fuzzy PID control algorithm were enabled,the average fog drop coverage rate at the edge of the canopy was 61.68%,and the average fog drop coverage rate between the trees was 10.85%.The results showed that when target spraying was used,the coverage of pesticides among the trees was significantly reduced and the target spraying effect was obvious.When the installation positions of laser ranging sensor group and sprinkler head group were changed and fuzzy PID control algorithm was enabled,the coverage rate of fog drops at the edge of the tree canopy was increased and the spray effect was improved.In addition,10 experiments were carried out under the two conditions of continuous spray and fuzzy PID control algorithm,and the amount of liquid medicine was statistically analyzed.It was found that the average saving amount of target spray was 33.9%higher than that of continuous spray.Under the condition of crawler release warning,the critical track release K_t was about 0.82.The PLC controller accumulatively recorded the service life of key components and compared it with the corresponding warning parameters.When the warning conditions were reached,the controller would give an alarm and inform the operator to carry out maintenance or replacement.The warning system was reliable.