AUTONOMOUS WHEEL POWER MANGEMENT SYSTEMS

ME 632/732 Autonomous Wheel Power Management Systems Homework Assignment

Week 5 and 6

4x4 Tractor: Tractive Running Gear Efficiency Computation Given Consider a 4x4 tractor in steady motion. The front wheels are in poor road conditions (mud), the rear wheels are in good road conditions (dirt road). The rolling resistance coefficient of the front wheels is f1 = 0.18. The rolling resistance coefficient of the rear wheels is f2 = 0.035. Friction coefficient of the front tire, pxµ , is 0.417; empirical coefficient, k , is 4.038 Friction coefficient of the rear tire, pxµ , is 0.721; empirical coefficient, k , is 8.034 The draw bar pull is 2kN, 4kN, 6kN, 8kN, 10kN. Assume Assume that the function )( δsfFx = is an exponential one. Consider a bicycle model of the tractor. Normal load on the front and rear wheels is the same and equal to 20kN. Determine For each value of the draw bar pull, compute tractive running gear efficiency of the tractor when the circumferential wheel split between the drive axles is q1 = 0.25; 0.50; 0.75; 1. q2 = 0.75; 0.50; 0.25; 0. Hint Rolling resistance coefficient is wx WRf /= . Dr. Vladimir V. Vantsevich Professor and Director Vehicle and Robotics Engineering Laboratory [email protected]