جستجوی مقالات مرتبط با کلیدواژه "نیروسنج" در نشریات گروه "مکانیزاسیون کشاورزی"

This study investigated the development and evaluation of an automatic feeder control system for sugarcane planters. The primary objective was to address limitations in existing machines and enhance their performance by introducing precise control of cane feeding.

The automatic feeder control system was equipped with three types of sensors, including a Load Cell Sensor that directly measures the weight of sugarcane on the feeder table. This feature provides a real-time assessment of cane availability. The Hydraulic Oil Pressure Sensor monitored the pressure within the hydraulic system that drives the feeder mechanism. Variations in pressure served as an indirect measure of the force applied to the cane during the feeding process. The Ultrasonic Distance Sensor employed ultrasonic waves to estimate the distance between the sensor and the sugarcane pile. Nevertheless, some limitations concerning accuracy and response time were identified. A microcontroller served as the central processing unit, receiving sensor data and generating control signals to regulate the feeder mechanism. This allowed for automation and eliminated the need for a manual operator. The performance of the automatic feeder control system was evaluated against a manual control method operated by a human.

The evaluation focused on three key aspects: cane spillage, planting quality, and control stability. Cane Spillage: the amount of sugarcane inadvertently dropped during the planting process. Automatic control methods using a load cell and hydraulic oil pressure sensor reduced spillage similarly to manual control, averaging approximately 8.8 t ha-1. The ultrasonic sensor resulted in significantly lower spillage, achieving 7.4 t ha-1. However, its limited accuracy and responsiveness led to undesirable gaps between the planted canes. Planting Quality: The implementation of automatic control techniques utilizing load cells and hydraulic oil pressure sensors successfully ensured uniform spacing between planted canes, achieving results comparable to traditional manual methods. Due to its shortcomings, the ultrasonic sensor created gaps between the planted canes, undermining the overall quality of the planting process. Control Stability: The method utilizing hydraulic oil pressure sensors exhibited limitations in maintaining consistent control under varying operational conditions. This stemmed from temperature-dependent changes in oil viscosity, which affected the pressure readings and ultimately the control signal. Based on the evaluation results, the load cell control method emerged as the most favorable option for automatic feeder control. It delivered performance that matches manual control in terms of cane spillage reduction and planting quality, all while eliminating the need for an operator. The hydraulic oil pressure sensor method, although effective in some aspects, presented challenges due to oil viscosity variations. The ultrasonic sensor showed promise for reducing spillage; however, it ultimately fell short due to its inability to accurately and swiftly detect the availability of cane, resulting in gaps between planted canes. A separate assessment was carried out to compare manual cultivation with an automatic control method based on weight measurements using a load cell. This evaluation revealed significant differences (p < 0.01) in billet weight, the number of billets utilized, and one-sided gaps between the two methods. However, no significant difference was observed in terms of two-sided gaps.

This study successfully designed and implemented an automatic feeder control system for sugarcane planters. The load cell control method emerged as the most effective solution, successfully eliminating the need for operators while ensuring high standards of planting quality and efficiency. Additional research could explore advancements in sensor technology and control algorithms to further enhance the performance of automatic feeder control systems.

The cereal combine harvester is one of the agricultural machines that works in difficult conditions and its parts are constantly under various static and dynamic loads. For the optimal design of vehicle parts, types and values of loads applied to them must be determined correctly. The purpose of this study was to design and fabricate an electronic system that could instantly measure and store the amount of vertical load exerted on the rear axle of grain combine harvester in various conditions to be used in the design and optimization of the axle.

Main components of the designed system included a steel coupling, a disc loadcell (H2F-C2-10t ZEMIC model), an electronic board for amplifying loadcell output voltage, a data logger (AdvanTech DAQ Navi model), a 12-volt battery, and a laptop. A special steel coupling was designed in CATIA software for connecting the loadcell to the axle. The loadcell was placed between the coupling plates and then the coupling was installed on the center point of the rear axle of a JD 955 combine harvester. A standard tensile-compression testing machine (Cantam STM-150) was used to calibrate the loadcell. The relationship between the input load and the loadcell output voltage was linear and had a high coefficient of determination (R2 = 0.9991). In the static test, the vertical load exerted on the axle was recorded by the electronic system while the combine was stopped and the combine engine was in ON/OFF modes. In the dynamic test, the combine was driven in three positions including asphalt road, dirt road, and wheat field at three different forward speeds, and loads on the rear axle were recorded by the electronic system. Finally, the data obtained from the tests were analyzed as a factorial experiment in a completely randomized design with five replications in Excel and SPSS software.

The average static loads on the combine rear axle in ON and OFF modes were 14.908 and 14.905 kN, respectively. The results of the Student's t-test of paired samples to compare the values of axle vertical loads in two modes of static load measurement showed that there is no significant difference between the axle loads in ON and OFF mode of the engine at 1% probability level. The average vertical loads on the rear axle of the combine were equal to 15.20, 15.27, and 15.28 kN, while driving on asphalt roads at speeds of 10, 15, and 20 km h-1 respectively. These values were equal to 17.57, 17.99, and 18.15 kN, while driving on the dirt road at speeds of 2, 4, and 6 km h-1 respectively, and they were equal to 16.47, 18.01, and 17.78 kN when harvesting wheat in the field at speeds of 3, 4, and 5 km h-1 respectively. The average load applied on the axle in the turning path was more than the load applied in the straight path, which indicates load transfer to the rear axle during turning. The effect of forward speed and path type on the amount of axle load was significant at a 1% probability level, but their interaction was not significant. Therefore, the critical conditions for applying load on the rear axle of combine harvester are occurred while combine turns with high forward speed, and the design of the axle should be based on these conditions. The maximum load on the axle was obtained equal to 50 kN on the dirt road, which was due to the combine movement on a steep uphill at the end of the path.

Evaluation of the system in different conditions showed that the performance and accuracy of the system are acceptable and the data of this system can be trusted and used to measure the vertical load on the rear axle of the combine. The current rear axle of the JD955 combine harvester looks relatively safe, but at some very rugged elevations, especially steep uphills, it suffers from a lot of stress that may cause damage. So, optimizing the axle such as increasing the thickness of the triangular piece in the middle of axis and using a stronger alloy for the middle areas of the axle are recommended.