Search Results (4)

The complex field environment under conservation tillage aggravates the vibration during a planter’s operation, affecting the sowing quality and fertilization depth. Studying its vibration characteristics can help to realize active vibration reduction control of planter row units. To this end, this paper took a four-row no-till planter as the research object. By establishing a field vibration model of the planter row unit, the factors affecting the vibration of the unit were clarified, and stubble height, working speed and the additional weight of the planter were used as experimental factors in carrying out field orthogonal experiments. In our experiment, we collected and analyzed vibration data on the four-row planter row units and the frame at different positions to explore the influence of various factors on the vibration characteristics of the planter. The experimental results showed that the working speed was the most important factor affecting the vibration of the planter, and the impact of stubble height and additional weight on the amplitude of the planter was more significant at low speed (1.5 m/s) than that at high speed (2.5 m/s). The difference in amplitude of each planter unit in the lateral direction was the largest, the average amplitude range of which was 1.898 m/s². The vibration energy of each planter row unit under different working conditions was mainly concentrated in the range of 10–50 Hz. However, the three-point hitch of the planter transmitted the vibration excitation of the tractor, causing 110–120 Hz high-frequency vibration of the inner row units, while the outer row units were less affected, with the vibration energy, in the range above 100 Hz, being 2.5 dB smaller than that on the inner side. The right ground wheel transmission device was abnormal, which worked together with the excitation transmitted by the three-point hitch, making the average vibration acceleration amplitude of the planter row units on the right side in the lateral direction more than 0.522 m/s² higher than that of the units on the left side. Therefore, different vibration reduction forces need to be applied according to the position of the planter row unit, so that the units can avoid the natural frequency of the frame (115 Hz) when vibrating. This study can provide a reference for active vibration reduction control and improvements in sowing quality for high-speed no-till planters. Full article

The three-point hitch, found on agricultural tractors, facilitates the raising and lowering of an attached implement. Some tractors include a rock shaft that comprises a physical shaft that interconnects and facilitates the raising and lowering of the lower arms of the three-point hitch in a synchronized manner. In this study, we deal with a hitch system with the lower arms actuated by two independent hydraulic cylinders. This innovative tractor hitch system design allows the implement to follow the terrain, instead of the tractor, about the fore–aft (roll) axis of the tractor. However, since the two lower arms are independent, a specialized controller is needed to move these arms in unison. First, we present a position controller for individual arms and a roll controller to move these arms together. Second, we present a unique algorithm to emulate a physical rock shaft while the implement is operating in float mode. The algorithm ensures that the implement does not roll around the fore–aft axis while making sure it moves up and down vertically to follow the terrain. We present experimental results from the step response of the hitch system’s height while tracking a velocity reference. With the roll of the implement defined as the difference between the left arm’s position in percentage and that of the right arm in percentage, we observe that the largest mean roll was 0.23% with a flail mower attached and 0.26% without any implement. We then present results from the implement’s position in the float mode when the software rock shaft was activated and compare them with the case without the software rock shaft. The experiments showed that, when the software rock shaft was turned on, the mean roll reduced from 4.64% to 0.58% with a seed drill implement and from −3.99% to −0.59% with a flail mower implement. The standard deviations in these two implement cases improved from 16.77% to 2.79% and 6.45% to 3.53%, respectively, proving the effectiveness of the software rock shaft and its potential to replace the physical rock shaft found on the traditional tractors. Full article

In the last decade, many studies have been conducted on tractor and agricultural machinery electrification. In particular, the electrification of power take-off (PTO)-powered implements could support many benefits, such as improved comfort and safety during implement connection, less noisiness, accurate control of the implement rotational speed, and fuel consumption reduction. However, commercially available tractors do not generate sufficient electric power to run electrified implements. A solution to this issue is powering eventual electrified implements with an external electric generator powered by the PTO and mounted with the front three-point linkage. This study aimed to evaluate the potential benefits of using this combination with respect to PTO powered implements. The types of implements analyzed in detail in this study were a sprayer and a mulcher. Field tests were performed acquiring performance, operational, and environmental parameters. Results show that on the electrified implements, the absence of the cardan shaft and hydraulic remotes shortened the time required for the hitching phase and reduced the in-work noisiness. Field tests demonstrated that the electrified implements permitted an improvement of the fuel consumption per hectare, up to 33.3% and 29.8% lower than their PTO-powered homologue for the sprayer and the mulcher, respectively. Full article

In this paper, the energy diagnostic of tractor performance consists in evaluating the energy (fuel consumption per hectare—dm³ ha⁻¹) for a given agricultural operation and in combining it with working capacity, also called productivity (area productivity—ha h⁻¹). One of the methods of solving this problem is the identification of the functioning process of the machine unit. A model of the process of the machine unit performance was developed, considering the operation of the rear linkage system of the implement with the force control adjustment system. In order to analyze the system, a mathematical model of the system function was built: tractor-implement-soil, defining the physical connections and interdependencies between the individual subsystems of the system. Based on this model, a simulation model was developed and implemented in the Matlab/Simulink environment. The Simulink package was used to test the performance of the machine set. The efficiency indicators according to the adopted criteria were calculated in the evaluation block. To evaluate the process, the technical and operational parameters of the tractor, the type and parameters of the tool, and soil properties were taken into account. The results of simulation studies obtained on a validated model are consistent with experimental data from appropriate soil conditions. Full article