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Green leafy vegetables are an essential component of Chinese leafy vegetables. Due to their crisp stems and tender leaves, orderly harvester generally causes significant mechanical clamping damage. The physical and mechanical properties of green leafy vegetables are one of the important basis to design the orderly harvester. At the same time, they provide important parameters for the simulation and optimization of harvester. So, this paper measured the physical characteristic parameters of roots and stems of green leafy vegetables. Then, based on the TMS-Pro texture analyzer, the elasticity modulus of the roots and stems of green leafy vegetables were measured. The static friction coefficient, dynamic friction coefficient, and restitution coefficient of green leafy vegetables root-root, stem-stem, root-steel, and stem-steel were measured separately using a combination method of inclined plane and high-speed photography. Uniaxial compression creep experiments were carried out on whole and single leaf of green leafy vegetables using the TA.XT plus C universal testing machine. The constitutive equation of the four-element Burgers model was used to fit the deformation curve of the sample with time during the constant-pressure loading stage. The fitting determination coefficients R2 were all higher than 0.996, which verified the reasonable validity of the selected model. The above experimental results provide a parameter basis and theoretical support for the design and discrete element simulation optimization of orderly harvester critical components of green leafy vegetables. [ABSTRACT FROM AUTHOR]

During the field operation of rice combine harvester, the vibration generated by vibration component will only reduce mechanical reliability and yield, but also cause resonance in the human body, leading to a decrease in driving comfort and even damage to the driver's health. To study the impact of combine harvester vibration on driving comfort, a certain type of tracked rice combine harvester was selected as the research object, and vibration tests were carried out based on vibration source analysis in the driving cab during field harvesting operations. The study showed that under the influence of field road conditions and crop flow, the operating speed of the engine, threshing rotor, stirrer, cutting blade, threshing cylinder, vibration sieve and conveyor were fluctuating, and their rotation and reciprocating motion would produce vibration excitation in the driving cab. A spectrum analysis was conducted on the acceleration signal of the driver's cab, and it was found that vibration frequencies at three measuring points, namely the pedal, control lever, and seat, can reach up to 36.7~43.3 Hz. These frequencies can cause resonance in various parts of the driver's body, such as the head and lower limbs, leading to symptoms such as dizziness, throat discomfort, leg pain, defecation anxiety, and frequent urination, and even affect vision of the driver. At the same time, a weighted root-mean-square acceleration evaluation method was used to evaluate the driving comfort of the harvester. The evaluation method showed that the vibration at the foot pedal (Aw1 = 4.4 m/s2>2.5 m/s2) caused extreme discomfort, while the vibration at the seat (0.5 m/s2< Aw2 = 0.67 m/s2<1.0 m/s2) and the control lever (0.5 m/s2< Aw3 = 0.55 m/s2<1.0 m/s2) caused relatively less discomfort. This research can provide some reference for the optimization design of the joint harvester driver's cab. [ABSTRACT FROM AUTHOR]