Study On Human-machine Collaboration Comfort Of Operating Chassis In Apple Nursery

Chinese apple cultivation is transitioning towards a dwarf rootstock and dense planting mode,requiring a large number of dwarf seedlings.However,there is still a lack of apple nursery operation chassi’s and functional devices for low height operations in China.This study designs a new type of apple nursery operation chassis,and combines ergonomic theory to study the human-machine collaborative comfort of the driver’s cab and operation workstation device,in order to reduce the intensity of nursery production management work and provide mechanical technology and equipment support for the highquality development of apple seedlings.Taking the integration of agricultural machinery and agronomy as the purpose,the three-year-old dwarf middle stock apple seedling cultivation process and nursery planting mode were investigated,and the AIP software was used to create the overall layout of the nursery operation chassis and its low-level operation functional devices.It is determined that the operating range of the low-slung operating station device is 3 to 5 rows.Based on GB/T 10000-1988 "Chinese Adult Human Body Dimensions",fitting and correcting the Chinese human body size data in recent years,and establishing male and female five percentile virtual humans in JACK.Match the nursery operation chassis and work station device with the Chinese sign virtual human in JACK to complete the establishment of the human-computer interaction model.Based on the human-computer interaction model and Proter joint angle research data,an evaluation index for cab comfort is established.According to the agricultural cab design standards,the steering wheel,pedal size and joints are divided to clarify the objects for the follow-up research.Using the orthogonal test method to analyze the comfort of the joint angle of the steering wheel grasped by the upper limbs,and establishing a response surface model,12 groups of optimization schemes are obtained for design selection;using the full factorial method to analyze the comfort of the joint angles of the lower limbs operating the pedals,and obtaining the installation height and side of the pedals recommended distance.Through the analysis of the comfortable head rotation angle field of view and the eyeball angle of view,the installation positions of the display,control switch panel,hydraulic controller and other components are determined.Considering the field of view and the convenience of operation,it is determined that the installation angle of the steering wheel shaft is 25°.the height of the installation point is 555 mm.the extension length of the shaft is 200 mm.the installation height of the pedal is 100 mm.and the side distance is 80 mm.In the cab.the driver can perform various operations smoothly,obtain information well.and the overall joint angle comfort score of the driving posture is 0.82.which is a comfortable level.Through the investigation of key indicators such as the typical low-slung operation process,active parts and duration of the nursery,such as stubble leveling,grafting,and sprouting,and according to the characteristics of the operation tasks,two solutions for sitting sideways and sitting upright are proposed.The results of the reachable area analysis showed that the side-sitting scheme was more suitable for the typical low-slung operation task requirements of the nursery.The results of the reachable area analysis showed that the side-sitting scheme was more suitable for the typical low-slung operation task requirements of the nursery.Further studies on the comfort of the side sitting program were carried out.The back pressure test results showed that the pressure on the lower back of men and women P5、P50、P95 who adopted the side sitting program decreased by 7.8%～8.9%and 11.7%～12.8%respectively,and the degree of pressure relief on the lower back of women was lower than that of men more obvious;Among the same sex group,larger individuals have more significant relief in lower back pressure.The results of metabolic energy analysis show that using the side sitting scheme,the average metabolic energy reduction of workers in the tasks of stubble leveling,sprouting removal,and grafting is 64.16%,55.96%,and 41.31%,respectively.The main reason for the decrease is that the task energy consumption has decreased significantly,ranging from 64.1%to 87.8%,and the posture energy consumption has also decreased by 10.9%to 14.2%.The frequency of grafting,stubble leveling,and germination removal in the side sitting scheme increased by 35.1%,650.0%,and 130.1%,respectively.The prototype was manufactured according to the design plan,and the performance test of the prototype was carried out.The results showed that the basic performance of the nursery operation chassis and the nursery passability were good.The comfort evaluation of the driver’s cab and work station devices were both 6-10 points,which was a relatively high level.The nursery operation chassis Design and Human-machine collaboration comfort meet the design requirements.