In view of the large amount of wheat straw coverage and the difficulty with the high-speed working process used in traditional rotary tillage row cleaner. A row cleaner with staggered disc teeth for no-till planting was designed. It was determined that installation with a forward inclination α, horizontal declination β, and forward speed v0 of the machine were the main factors affecting the straw cleaning rate Y1 and working resistance Y2, and the range of values for structural parameters and motion parameters of the row cleaner were determined. Taking α, β, and v0 as the factors and Y1 and Y2 as the response indexes, using EDEM 2018 software to simulate the straw cleaning process under different parameters and determine the influence of each parameter on the straw cleaning performance. After performing a soil bin test, the results showed that there was no straw entanglement and blockage, and the passability was better than that of the traditional flat disc separated row cleaner. When α was 70°, β was 30°, v0 was 8 km/h, and the embedded depth h of the soil (straw) was 55 mm, the average straw cleaning rate was the highest, which was 90.59%. This study provides a new idea for the design of high-speed corn no-till planters in the Huang-Huai-Hai area of China.
This paper details study of the anti-symmetric response to the symmetrical electrostatic excitation of a Micro-electro-mechanical-systems (MEMS) resonant mass sensor. Under higher order mode excitation, two nonlinear coupled flexural modes to describe MEMS mass sensors are obtained by using Hamilton’s principle and Galerkin method. Static analysis is introduced to investigate the effect of added mass on the natural frequency of the resonant sensor. Then, the perturbation method is applied to determine the response and stability of the system for small amplitude vibration. Through bifurcation analysis, the physical conditions of the anti-symmetric mode vibration are obtained. The corresponding stability analysis is carried out. Results show that the added mass can change the bifurcation behaviors of the anti-symmetric mode and affect the voltage and frequency of the bifurcation jump point. Typically, we propose a mass parameter identification method based on the dynamic jump motion of the anti-symmetric mode. Numerical studies are introduced to verify the validity of mass detection method. Finally, the influence of physical parameters on the sensitivity of mass sensor is analyzed. It is found that the DC voltage and mass adsorption position are critical to the sensitivity of the sensor. The results of this paper can be potentially useful in nonlinear mass sensors.
The V-shaped toothed roller cotton stalk puller has a low removal ratio and weak pulling effect. Hence, we constructed a simplified mathematical model of the V-shaped tooth roller stalk puller based on elastic collision theory and simple beam theory and conducted a mechanical analysis based on this model to explore the causes of pulling errors and fractures. Specifically, the V-shaped tooth plates of the machine were optimized in an orthogonal experiment with the rotational speed, cogging angle, and ground clearance as the influencing factors, and the removal ratio as the evaluation index. This experiment was designed to enable analysis of the physical characteristics of cotton stalks, and the forces applied during the pulling process. Additionally, a V-shaped toothed roller-type stalk-pulling test bench was constructed. The results revealed that, unlike the cogging angle, the ground clearance significantly affected the removal ratio. Furthermore, the highest removal ratio (i.e., 97%) was achieved when the ground clearance was −20 mm, the rotational speed was 300 rpm, and the cogging angle was 32.5°. An L9 (34) orthogonal field experiment was also conducted with the rotational speed, cogging angle, and ground clearance as the influencing factors to investigate their respective influences on the stalk removal ratio. The results revealed that the ground clearance most significantly influenced the ratio, followed by the rotational speed, and cogging angle. The ground clearance and rotational speed of the V-shaped toothed roller were each found to significantly influence the ratio. Furthermore, a ground clearance of −20 mm, rotational speed of 300 r/min, and cogging angle of 25° yielded an average removal ratio of 98.27%. Through this research, the mechanism of toothed roller stalk pulling is further deepened and the toothed series stalk pulling technology provides theoretical support.
31 August 2023 in INMATEH Agricultural Engineering
In this paper, a small pneumatic vegetable precision seeder suitable for facility greenhouses was designed. Based on the traditional positive and negative pressure seed-metering device, the airway disc structure was designed, and the negative pressure air chamber was divided into three separate air chambers. The separate air chambers could solve the problems of high-pressure requirements of traditional seed-metering device with large air chamber and suitable for small power machineries more. One, two, or three rows drill can be completed by replacing the seed plate and divider. The seed discharge process of the seed-metering device was analyzed and the bench test was performed. Results showed that the required pressure of the seedmetering device with the airway disk was 1 kPa less than traditional seed-metering device with large air chamber when the eligible rate of seed discharge was 95%. Field experiments were performed, results showed that the best performance were achieved under the speed of 3 km/h, for 3.72 % missed, 1.93% repeat and 94.35 % of inner ring, and 5.72%, 1.87% and 92.41% respectively of outer, meeting the requirements for vegetable seeding.
This paper aims to explore issues related to destruction of soil nutrients and structure in a rice-wheat double-cropping area caused by over-tillage prior to rice cultivation. A three-year cycle of rotation tillage pattern (RT), consisting of “no-tillage–no-tillage–plough”, with a straw-returning and direct rice-seeding technology, was designed and tested, and was compared with continuous no-tillage pattern (CN) and conventional ploughing & rotary tillage (PR). The soil rotation experiment in the rice-wheat double-cropping region is located on the southeastern coast of Shandong Province, with a warm, temperate, humid monsoon climate and paddy soil type. Comparison experiments were conducted on the three farming patterns over a period of 3 years, continuously measuring soil physical and chemical properties and crop yields. The results showed that under the same straw-returning conditions, RT significantly increased soil macroaggregates content and enhanced their stability within 0~30 cm (p < 0.05). RT significantly reduced the bulk density of 0~30 cm soil to below 1.5 g/cm3, which was beneficial to crop root growth (p < 0.05). Meanwhile, RT significantly increased the contents of soil organic carbon, total nitrogen, and available phosphorus, and the nutrients are evenly distributed in 0~30 cm layer (p < 0.05). Another result was that the RT significantly increased the rice panicle length, grains number per panicle, and thousand-grain weigh. The crop yield was not significantly different from that of PR, but significantly higher than that of CN (p < 0.05). At the same time, cultivation measures prior to rice cultivation had some after-effects on wheat; the RT significantly increased the average tillers, effective panicle number, effective panicle grain number, and thousand-seed weight of wheat; and the wheat yields were 10.5% and 13.3% higher than that of CN and PR, respectively. This study provides a theoretical reference for improving tillage patterns in rice-wheat double-cropping areas.
To address the issues of large turning radius, low mechanical compression bale density, and high requirements for knotters in existing towed straw balers, a self-propelled straw-harvesting and -baling machine has been developed. The machine can perform multiple tasks in one pass, including the harvesting, chopping, dust removal, compression bale, and net-wrapping of corn straws. By utilizing a hydraulic closed-compression system, the straw naturally binds together and is wrapped in netting, eliminating the need for knotters, thereby reducing operational costs and increasing bale density. This study focused on designing a baling compression and net-wrapping device, calculating the parameters of the compression hydraulic cylinder and hydraulic system, designing the control system, and conducting field tests. The results show that the finisher baling rate reached 99%, the regular bale rate reached 100%, the bale density was 264.77 kg/m3, the bale drop resistance rate was 94%, and the pure working hour productivity was 4.03 t/h. This research provides a reference for the design of straw-harvesting balers.