TY JOUR TI MATHEMATICAL MODEL FOR DETERMINATION OF TOOL DEVIATIONS FROM THE DESIRED TRAJECTORY IN ROBOTIC MACHINING CONSIDERING THE ROBOT'S STIFFNESS KW industrial robot KW dynamic stiffness KW virtual joint modeling KW trajectory KW Matlab JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Volkov, D.I. AU Vorob'ev, P.S. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov