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.

In light of the current dearth of strip intermittent fertilization devices in standardized orchards, this study presents the design of an intermittent fertilization control system based on fruit tree crown detection, developed with the objective of meeting the agronomic requirements of strip furrow fertilization in standardized orchards. The initial stage of the process entails the design of the essential components of the fertilization apparatus, followed by the construction of the intermittent fertilization control system. The ultrasonic sensor was employed as the fruit tree crown detection module, and a mathematical model of fertilization speed was constructed to achieve uniform intermittent fertilization. Furthermore, in order to enhance the responsiveness and reliability of the fertilization servo motor, MATLAB Simulink was employed to assess the dynamic performance of the system under disparate control strategies. Ultimately, to validate the simulation outcomes, a field trial was conducted to assess the precision and uniformity of intermittent fertilization. The results demonstrate that the dynamic performance of the system under the fuzzy PID control strategy is optimal, and the coefficient of variation of the fertilizer uniformity of the intermittent fertilization device is less than 7%. The mean effective fertilization rate exceeded 85%, with the primary indices satisfying the agronomic criteria.

Based on the cultivation environment and material parameters of Pleurotus pulmonarius sticks, a P. pulmonarius stick cutting machine is designed to solve the problem of directly realizing the cutting of P. pulmonarius sticks for a net-shaped mushroom stick cultivation layer frame. The machine consists of three parts: a traveling trolley, an XYZ three-axis moving mechanism, and a clamping and cutting mechanism. Based on the force analysis of the clamping and cutting mechanism and the P. pulmonarius sticks, the key components were designed and selected. A prototype was constructed, and several cutting tests were conducted, with the cutting speed, number of cutting circles, and depth of the cut as the main factors. The success rate of cutting, the roundness of the cut, and the degree of loss in terms of the cutout substrate, were used as the performance indicators. An optimized design, based on orthogonal testing, was employed to determine the optimal parameter combinations for the cutting process. The optimal parameters were found to be a cutting speed of 376.3 r/min, 5.4 cutting circles, and a cutting depth of 4 mm. Finally, a validation test was carried out on the machine, and the results show that under the same parameter conditions, the success rate of cutting was 86.6%, the roundness of the cut was 0.235, and the degree of loss in terms of the cutout substrate was 0.851%, which is consistent with the optimization results. This study provides a reference, including a practical reference, for the design and development of a machine to realize the cutting of P. pulmonarius sticks for a cultivation layer frame.