| China has a large fruit growing area and high output value,but the mechanization rate is low.With the gradual increase in labor costs and the gradual aging of orchard labor,there is an urgent need for mechanization and intelligence in orchard.Due to the characteristics of uneven ground in the orchard,there are high requirements for lawn mowers with climbing and terrain adaptability.And considering the convenience and safety requirements of the operation,this study carried out the design and test research of the orchard electronic controlled mower.This study also attempted to make a mountain orchard lawn mower prototype,and to carry out some related tests,so as to realize stable and efficient weeds cutting under the mountain terrain conditions.The main contents of this paper include:(1)The overall mechanical structure design of Mountain Orchard profiling mower was completed.According to the characteristics of Mountain Orchard working environment and the demand of mowing,the design index requirements of mower in climbing,trafficability,uneven ground adaptability and intellectualization were put forward.In order to improve the flexibility of operation,the overall structure scheme composed of profiling header and crawler chassis was selected.Crawler chassis can meet the needs of mountain orchard slope operation,and the profiling header can adapt to the profile cutting operation of uneven ground.In the structure design of profiling header,the cutting mechanism,profiling mechanism and cutting angle adjustment mechanism were designed.According to the requirements of operation width and trafficability,the type and size of cutting mechanism of the header were determined by analysis and calculation,the range of cutter speed was selected according to the demand of weed cutting line speed,and the resonance speed was avoided by cutter modal analysis.According to the complex terrain characteristics of orchard working environment,the longitudinal profiling mechanism was designed,and the buffer depth limiting mechanism was added,so that the header can adapt to the uneven terrain in the process of operation.Through mechanical calculation,the profiling amount of the mechanism is ± 12 cm.In order to improve the cutting efficiency and reduce the energy consumption,the cutting angle adjustment mechanism with angle adjustment range 0-50° was designed.In the aspect of crawler chassis design,according to the climbing range,trafficability and load requirements,the overall structure of crawler chassis was designed,and the independent suspension mechanism was designed,so that the chassis can operate stably in the terrain with a height difference of 10cm;the chassis structure layout was designed,and the trial production of crawler chassis was completed.The maximum climbing angle of the chassis is 25 ° and the maximum traveling speed is 1.2m/s.Through the integration of header and chassis,the structure design of orchard profiling mower was completed.The theoretical cutting width is 610 mm,the cutting angle adjustment range is 0-50 ° and the cutting speed range is 0-6000 rpm.It has the passive profiling function,and can meet the walking and mowing needs of Mountain Orchard.(2)The software and hardware design of orchard mower control system was completed.According to the mowing operation regulation,safety requirements and intelligent requirements of the mower,combined with the characteristics of the overall mechanical structure,the overall control system of the mower was designed.Consistent with the mechanical structure,the mower control system was divided into two parts: the header and the chassis.Through the overall wireless remote control and internal wired control,the control of the whole mower by single signal source was realized,which solved the problem of cooperative control between the header and the chassis,retaining the automatic control function interface.In the specific control information processing,through the sampling and analysis of different control signals,the problems of signal analysis and serial communication information calculation were solved.In the specific motor control,the cutting tool drive motor control algorithm and cutting angle adjustment mechanism control algorithm were designed,and the crawler chassis drive motor control algorithm was completed.The maximum offset speed is 8.2 rpm when the preset speed is 5400 rpm.The control system was integrated into the designed header and chassis,and the prototype design and trial production of orchard mower was completed.(3)The stability tests and operation effect tests were carried out.In order to verify the cutting width,profiling function and cutting angle adjustment function of the mower,the stability test of the mower was carried out.The test results show that the average effective cutting width utilization rate of the prototype is 96.59%;under the terrain conditions of 2.39-6.72 cm of ground roughness and 19.6cm of maximum ground height difference,the stubble cleaning rate of the mower is more than 98.1%;the maximum deviation of cutting angle adjustment is less than 4.0°.In order to verify the best combination of cutting speed and forward speed of the prototype within the test range on the premise that the cutting effect meets the requirements,the operation effect test was carried out.The test results show that when the forward speed is 0.4m/s and the cutting speed is 6000 rpm,the comprehensive energy consumption coefficient is the lowest and the cutting efficiency is the highest.To sum up,according to the needs of Mountain Orchard mowing,through the mechanical structure design,control system design and implementation,the prototype of Mountain Orchard electric control mower has been completed.Through the stability test and machine cutting test verification,the whole mower runs smoothly,and can adapt to the mountain terrain climbing and profiling mowing requirements,which provides a reference for future mower design. |
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