The parameters of a discrete element simulation model for commercial organic fertilizer particles were obtained both quickly and accurately, so that the uniformity and stability of the fertilizer discharged from the feeder may be studied using the discrete element simulation method. This study...

Low working efficiency is an important reason for the limited application of the traditional aspirated-air type jujube fruit pickup machine. In this study, a provoke-suction type harvester for ground jujube fruit (PSH) was designed, based on the principle of negative pressure suction after shoveling the jujube fruit mechanically. The main working parameters were analyzed and the structures of the key devices were designed. Then, a three-factor and three-level Box–Behnken method was used to evaluate the performance of the PSH. The results showed that the pickup rate, impurity rate, and working efficiency were 99.36%, 5.63%, and 1672.3 kg∙h⁻¹, respectively; as the forward speed, provoke teeth buried depth, and airflow velocity were 0.21 kg∙h⁻¹, 74 mm, and 26.4 kg∙h⁻¹, respectively. Furthermore, the verification results showed that the pickup rate, impurity rate, and working efficiency were 98.05%, 5.97%, and 1591.2 kg∙h⁻¹, respectively, moreover, the relative errors were 1.32%, 6.04%, and 4.85%, respectively, indicating that the parameter optimization model can accurately predict the test results. The working efficiency of the PSH was significantly improved compared with the traditional aspirated-air type jujube fruit pickup machine. This research can provide a reference for the development of the jujube fruit pickup machine.

Aiming at the mismatch between the cutter combination of the furrowing device and the operating parameters, and resulting in low quality of furrowing and other problems, the theoretical analysis of the furrowing cutting operation is carried out and the influence law of the furrowing parameters on the trajectory, performance and quality of the furrowing movement is obtained. The influence of trenching parameters on trenching trajectory, performance and quality was obtained. The response surface method was applied to design and carry out field experiments. With the increase of cutter head speed and forward speed, the width and depth of trenching and the thickness of floating soil at the bottom of trenching decreased first and then increased, while the operation power consumption presented the increasing trend gradually. The optimization model of trenching performance quality was constructed to obtain the optimal parameter combination of influencing factors. Field experiments were carried out to verify the optimization results. The optimisation results were verified through field tests, which showed that the average depth of furrowing was 472 mm, the width was 332 mm, the thickness of soil return was 134 mm, and the operating power consumption was 19.95 kW. The results showed that the average depth of furrowing was 472 mm, the width was 332 mm, and the thickness of soil return was 134 mm. The optimization model could meet the operation quality indexes, and provide a theoretical basis for the design of the disc subsection cutting trenching device to select the operation parameter combination required by low power consumption and deep trenching.

The amplitude of excitation force from exciters used in fruit tree vibration harvesting remains constant at a given frequency, leading to poor fruit detachment ratio and tree damage. A solution has been proposed through the development of a Double-Symmetric Eccentric Exciter (DSEE). This new exciter allows for the adjustment of excitation force amplitude while maintaining a constant frequency by varying the phase angle of the DSEE. To validate the effectiveness of the DSEE, vibration tests were conducted on fruit trees using different parameter exciting forces. Acceleration sensors were employed to measure the vibration accelerations of the tree branches. The experimental results revealed that when a fixed frequency excitation force with a constant phase angle was applied to the trunk, the vibration acceleration of branches exhibited inconsistent variations due to differences in the vibration differential equation parameters of each branch. Furthermore, it was observed that increasing the phase angle of the DSEE at a fixed frequency led to larger vibration accelerations in every branch. This signifies that adjusting the phase angle of the DSEE can effectively increase the amplitude of the exciting force. Consequently, the ability to control both the amplitude and frequency of the excitation force independently can mitigate issues such as low fruit harvest rates and minimize damage to fruit trees.