TY JOUR TI THE TRACKED VEHICLE INTERACTION WITH THE OBSTACLE KW functioning KW hardware KW wood raw materials KW classification of forest obstacles KW caterpillars KW traction effort KW adhesion KW vertical wall JO Bulletin of KSAU AU Kholopov, V.N. AU Labzin, V.A. PY 2015 IS PB Krasnoyarsk State Agrarian University