Year: 2025
Type: article
Abstract: Highlights A center frame hydraulic lift suspension for an agricultural self-propelled sprayer was instrumented and tested to further understand center frame and boom dynamics. Hydraulic accumulator precharge, volume, and system flow rate variables were manipulated to quantify the effect on lift suspension performance. The default accumulator precharge (83 bar) and orifice diameter (6 mm) provided the best overall performance for this suspension system across a multitude of drive profiles and specific field events. ABSTRACT. Improving the accuracy of fertilizer and herbicide application for self-propelled sprayers is an important part of modern precision agriculture. Multiple efforts across the private and public sectors have been made to improve boom height stability. Through various mechanical linkages and suspension systems, boom systems have been designed to be less coupled to the vehicle’s chassis, thus further mitigating unwanted dynamics from reaching the boom system and therefore providing a more stable boom platform. The suspension system studied in this research is a center frame lift assembly, which is intended to reduce the vertical coupling of the booms to the chassis. This lift system is composed of two mechanical lift arms, two hydraulic cylinders, and a hydraulic accumulator. Features of the accumulator were manipulated to better understand the lift assembly’s behavior. This included the accumulator’s precharge pressure, volume, and inclusion of an orifice in the hydraulic schematic that connects the accumulator to other components. Tests were conducted for a range of field profiles, speeds, and boom target heights, and a virtual simulation model was developed to aid in the development of the overall test matrix. The initial objective of this study was to characterize the suspension system across its entire operating range, as well as explore how manipulating the precharge affected system performance. A second set of testing was done for different accumulator volumes and orifice diameters. The data pertaining to the various levels in precharge revealed that the lowest precharge setting of 83 bar (1200 psi), also with a corresponding 2 L accumulator volume, was optimal for this suspension system. The second set of tests showed that the largest orifice diameter of 6 mm, from the possible 2, 4, and 6 mm configurations, yielded the best performance across test configurations. Regarding the changes in volume between 2, 4, 6, and 8 L, larger volumes were best for high-amplitude field events, while the smallest volume, 2 L, generally proved to be best for normal field operation. Keywords: Accumulator, Boom, Hydraulics, Lift system, Orifice, Pressure, Self-propelled sprayer, Suspension.
Source: Journal of the ASABE
DOI: 10.13031/ja.16254
Institution: Iowa State University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: bronze
Funder: Iowa State University
OpenAlex ID: W4412571592