Abstract—Evaluating and measuring the performance parameters of wheels and tillage equipments under controlled conditions obligates the use of soil bin facility. In this research designing, constructing and evaluating a single-wheel tester has been studied inside a soil bin. The tested wheel was directly driven by the electric motor. Vertical load was applied by a power bolt on wheel. This tester can measure required draft force, the depth of tire sinkage, contact area between wheel and soil, and soil stress at different depths and in the both alongside and perpendicular to the direction of traversing. In order to evaluate the system preparation, traction force was measured by the connected S-shaped load cell as arms between the wheel-tester and carriage. Treatments of forward speed, slip, and vertical load at a constant pressure were investigated in a complete randomized block design. The results indicated that the traction force increased at constant wheel load. The results revealed that the maximum traction force was observed within the %15 of slip. Keywords—Slip, single wheel-tester, soil bin, soil–machine, speed, traction. I. INTRODUCTION RACTION performance of agricultural wheels can be measured at farm by wheel-tester or tractors. Farm measurements are often unreliable due to inconsistencies in soil conditions and sudden changes. Factors that affect tire performance are so complex and therefore make it difficult to determine the impact of each factor. Although the tester systems are considered somewhat of an artificial environment, but if the proper equipment is being utilized to control soil conditions, it is easily to manage the objective parameters and yield highly accurate results. Then again, many computer modeling have been applied in soil wheel interaction domain. Hence, a controlled condition to obtain reliable empirical data is necessary. When the wheel is equipped with pneumatic tire, the privilege of applying only one unit in soil bin facilities is considerable. Al-Janobi and M. Zein Eldin [1] developed an indoor soil- bin test facility for soil-tillage tool interaction studies. It included a stationary soil-bin, a carriage and control unit. The instrumentation system consisted of an extended octagonal ring transducer for measuring force a magnetic pickup to check velocity. Kawase et al. [2] developed an indoor traction Ali Roozbahani, Aref Mardani, and Roohollah Jokar are with the Mechanical Engineering of Agricultural Machinery Dept., Urmia University, Iran (e-mail: alirzbhn@gmail.com, a.mardani@urmia.ac.ir, jokar16@ gmail.com). Hamid Taghavifar is with the Mechanical Engineering of Agricultural Machinery Dept., Urmia University, Iran (corresponding author to provide phone: + 98 441 2770508; fax: + 98 441 277 1926; e-mail: hamid.taghavifar@gmail.com). measurement system consisting single wheel tester, mixing and compaction device for soil processing, soil bin and traction load device. This facility provided the ability to investigate the tire driving torque, sinkage, velocity, and positioning the tire lug. Tiwari et al. [3] developed a tire traction testing facility which was capable of giving continuous reading of forward speed, wheel speed, draft force and torque. It could provide either of constant or varying slippages and tractions. Upadhyaya et al. [4] designed and constructed a single wheel traction machine to study soil- wheel interactions. The objective parameters to be examined were velocity, wheel load, torque and traction by two controlling methods for slippage and traction. However, this machine had the disadvantage of restriction in wheel load, engine operating condition and traction force. A field single wheel tester was introduced by Shmulevic et al. [5] featuring to conduct traction tests. The utilized tire was selected to bear heavy wheel loads, high traction forces and lateral forces and adapt tires with up to 2m diameter. Others examined the development of single wheel-tester to perform traction tests. For instance, the National Soil Dynamic Laboratory in Auburn, USA [6], Silsoe Research Institute, UK [7], University of California at Davis, USA, with combination of farm tests and soil bin facility using a driven test tire towed by a tractor while the difference between the forward speed of the system and rotational speed of tire provided various slippages [4], and University of Hohenheim, Germany, with the conspicuous characteristic of driven angled wheel tester [8]. National Soil Dynamics Laboratory (NSDL) developed a single wheel-tester with hydraulic driving force in order to perform traction tests under various conditions of soil. This device provided the independent control of slippage and dynamic load while either of them could be constant and the other one varying. Wheel load over the tester developed by NSDL could be increased to 72 kN and traction up to 44.5 kN. A tester was designed and built [6]. The hydraulic controller was used for controlling the forward speed, wheel rotational speed and dynamic load. In NSDL collection of testers inside soil bin and farm were developed by Thomas in 2006 (Way, T.2007). A single wheel tester named NIAE Mk-II provided the experiments in farm with controlling slippage and forward speed and holding wide range of agricultural tires. This tester was capable to stand 27.2 kN wheel load and 25 kN draft force. One main drawback of this tester was its failure to provide various dynamic loads during the test. The main purpose of this study was to provide a single- wheel tester with high capabilities in order to measure the parameters related to wheel and soil interactions as well as Evaluating and Measuring the Performance Parameters of Agricultural Wheels Ali Roozbahani, Aref Mardani, Roohollah Jokar, Hamid Taghavifar T World Academy of Science, Engineering and Technology International Journal of Agricultural and Biosystems Engineering Vol:7, No:2, 2013 158 International Scholarly and Scientific Research & Innovation 7(2) 2013 ISNI:0000000091950263 Open Science Index, Agricultural and Biosystems Engineering Vol:7, No:2, 2013 publications.waset.org/9996947/pdf