子恒 方

Mr. 子恒 方

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 October 2024 in Agriculture
Verified
Journal Article
Open access
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子方子恒 方
子恒 方
JZJing Zhang
Jing Zhang
JCJincheng Chen
Jincheng Chen
Feng PANFeng PAN
Feng PAN
BWBaiwei Wang
Baiwei Wang
Chao JiChao Ji
Chao Ji
The uniformity of the wheat distribution within and between rows has a significant effect on crop population structure, leading to decreased yield as nonuniformity increases. Traditional drills are influenced by soil porosity and flatness in the field, making accurate control of sowing depth and amount challenging and resulting in an uneven spatial distribution of gramineous seedlings. Precision cave-sowing technology effectively enhances wheat population distribution uniformity. However, owing to limitations in existing mechanical precision cave planters, their operational speed is lower than that of drill planters. To address these issues, this study designed an air-suction precision wheat seed dispenser, described its basic structure and working principle, and developed a seed mechanical model. A theoretical analysis was conducted on the working process and key components of the seed feeder. A suitable mould hole diameter was determined to be 1.6~2.0 mm, and the rotation speed range for the seed plate was found to be 65~85 r·min−1. Fluent simulations were used to determine the influence of orifice type on gas chamber flow fields; DEM-CFD-coupled simulation identified an appropriate negative pressure range of 2.6~3.4 kPa for optimal performance during seeding operations. Orthogonal experiments were carried out with mould hole diameter, negative pressure size, and seed plate speed as test factors alongside a qualification index, multiple sowing index, and missed sowing index as response indicators—leading to regression equation establishment, which yielded the optimal parameter combination: mould hole diameter at 1.8 mm; gas chamber negative pressure at 3.2 kPa; and a seed plate speed of 74 r·min−1, with the corresponding forwards speed of the machine being 7 km·h−1—resulting in a qualification index of 91.66%, multiple sowing index of 5.98%, and missed sowing index of 2.36%. This pneumatic suction type wheat precision seeder achieves equivalent operational speeds as traditional drills while enabling precision seeding.

29 June 2025 in Agriculture
Verified
Journal Article
Open access
PDF file
Feng PANFeng PAN
Feng PAN
JCJincheng Chen
Jincheng Chen
BWBaiwei Wang
Baiwei Wang
子方子恒 方
子恒 方
JLJinxin Liang
Jinxin Liang
Chao JiChao Ji
Chao Ji
The disadvantages of traditional strip fertilization technology for corn planting in China include low fertilizer utilization rates, unstable operation quality, and environmental pollution. Therefore, in this study, a synchronous hole fertilization device for corn planting based on real-time intelligent control is designed, aiming to reduce fertilizer application and increase efficiency through the precise alignment technology of the seed and fertilizer. This device integrates an electric drive precision seeding unit, a slot wheel hole fertilization unit, and a multi-sensor coordinated closed-loop control system. An STM32 single-chip micro-computer is used to dynamically analyze the seed–fertilizer timing signal, and a double closed-loop control strategy (the position loop priority is higher than the speed loop) is used to correct the spatial phase difference between the seed and fertilizer in real time to ensure the precise control of the longitudinal distance (40~70 mm) and the lateral distance (50~80 mm) of the seed and fertilizer. Through the Box–Behnken response surface method, a field multi-factor test was carried out to analyze the mechanism of influence of the implemented forward speed (A), per-hole target fertilizing amount (B), and plant spacing (fertilizer hole interval) (C) on the seed–fertilizer alignment qualification rate (Y1) and the coefficient of variation in the hole fertilizing amount (Y2). The results showed that the order of primary and secondary factors affecting Y1 was A > C > B, and that the order affecting Y2 was C > B > A; the comprehensive performance of the device was best with the optimal parameter combination of A = 4.2 km/h, B = 4.4 g, and C = 30 cm, with Y1 as high as 94.024 ± 0.694% and Y2 as low as 3.147 ± 0.058%, which is significantly better than the traditional strip application method. The device realizes the precise regulation of 2~6 g/hole by optimizing the structural parameters of the outer groove wheel (arc center distance of 25 mm, cross-sectional area of 201.02 mm2, effective filling length of 2.73~8.19 mm), which can meet the differentiated agronomic needs of ordinary corn, silage corn, and popcorn. Field verification shows that the device significantly improves the spatial distribution of the concentration of fertilizer, effectively reduces the amount of fertilizer applied, and improves operational stability and reliability in multiple environments. This provides technical support for the regional application of precision agricultural equipment.

4 April 2026 in Journal of Vibration and Control
Verified
Journal Article
Closed access
JYJialing Yao
Jialing Yao
YDYongchang Du
Yongchang Du
子方子恒 方
子恒 方
To address the inherent underactuation of active suspension systems under bounded external disturbances, a robust ride quality control strategy is developed within the high order fully actuated (HOFA) system framework. Departing from conventional active suspension controllers formulated in a first-order state-space framework, this study revisits the problem from the perspective of high-order system dynamics. By incorporating auxiliary control inputs, the original high-order suspension dynamics are structurally decoupled and reformulated into an equivalent fully actuated form. Based on the reconstructed fully actuated model and employing the direct parameter method within the HOFA framework, a robust stabilization controller for vehicle ride comfort regulation is devised while attenuating bounded external disturbances via a robust compensatory term. The proposed framework preserves the system’s high-order physical properties and enables explicit controller design, significantly simplifying the control structure and stability analysis. Furthermore, rigorous Lyapunov-based analysis theoretically guarantees the global stability of the closed-loop system, with all state variables converging to an arbitrarily small neighborhood of the desired equilibrium. Finally, extensive numerical simulations, corroborated by analytical investigations, confirm the validity and superior performance of the proposed method.