Influence of soil and tire parameters on traction

Abstract

Abstract:The drawbar pull, travel reduction (slip), and rolling resistance are the main criteria to describe the traction behaviour of off road vehicles. Besides the engine performance, the drawbar pull is influenced by the traction conditions such as soil and the tire parameters. These traction conditions have to be described by a limited number of parameters which can be easily determined. Empirical equations were used to analyse roughly 850 traction curves measured and published by Steinkampf. As a result, the important parameters to describe the traction conditions are three tire parameters (radius, width, inflation pressure) and five soil parameters (soil cover, upper soil strength, lower soil strength, clay content, moisture content). These parameters with relative values between 0 and 100% are used to establish the equations for the traction prediction. Main steps to achieve this goal are the extension of the traction slip equation by a linear term of slip, and the description of this curve by 4 meaningful characteristic coefficients: the x-and y-coordinates of the κ-maximum (σ κmax , κ max ), the y-axis intercept ρ e , and the gradient of κ at zero slip (κ'(0)).

Longitudinal vehicle dynamics model for construction machines with experimental validation

“…More information on complex modelling of rolling resistance can be found in [12] and [22]. Other works have included further resistances, including those stemming from the deformation of soil at the tire-ground interface [23,24]. Equation (2) includes Iw, the moment of inertia of the wheel; TE, the engine torque being applied on the wheel; TB, the braking torque; and rd, the dynamic radius of the wheel.…”

Evaluation of Driving System and Modification of Corn Planter Powered by Hand Tractor

“…Tiap jenis roda mencapai kemampuan torsi putar untuk mengatasi kebutuhan torsi putar sistem penjatah pada tingkat luncuran yang berbeda dari 21-35%. Hasil ini sejalan dengan hasil penelitian Schreiber and Kutzbach ( 2008) di mana net traction ratio roda di lahan pertanian akan meningkat seiring peningkatan slip roda hingga sekitar 20-25%, dan akan menurun setelah Tabel 1. Nilai kohesi, sudut gesekan dalam, adhesi dan sudut gesekan tanah-bahan itu.…”

Development of an Instrumentation System for Evaluating the Tractive Performance of Walking Tractors

“…For proper implement matching and field management of walking tractor, its tractive performance should be measured in different field conditions. Parameters included in the traction performance of off-road vehicles on unprepared terrain are driving torque, ability to accelerate, drawbar pull, travel reduction (usually called slip), gross traction ratio, tractive efficiency, net traction ratio (sometimes called pull/weight ratio), motion resistance or rolling resistance (Goering, 1989;Wong, 2001;Schreiber and Kutzbach, 2008;Zoz and Grisso, 2003).…”