Simulation model of a high speed tracked vehicle powertrain with step track gear boxes

BACKGROUND: One of the basic requirements for the tracked vehicle spatial motion simulation models to be used for multiple simulations or to be embedded into driving simulators and into controllers of the on-board control systems is high computational efficiency. AIM: The article describes the development of a simulation model of a high speed tracked vehicle powertrain with step track gear boxes to be inserted as a subsystem into a highly computationally efficient model of the tracked vehicle curvilinear motion. METHODS: In order to increase the model efficiency, the dynamics of the transmission gears is neglected, their internal kinematics being described by their gear ratios. External kinematics of the transmission is provided by the algorithms of the drive wheel speed regulators. The engine torque is defined as a function of the engine crankshaft rotational speed. The engine crankshaft is coupled to the transmission by means of the dry friction model simulating the operation of the friction gear-shift mechanisms of the track gear boxes. The simulation model of the powertrain has been implemented in Matlab\Simulink and built as a DLL module into a three-dimensional multi-body model of the tracked vehicle chassis dynamics developed by the author in the Universal Mechanism MBS-software. The resulting integrated model was used for the simulation of the tracked vehicle steering in different gears and calculation of theoretical minimum turning radii. RESULTS: The radii obtained by simulation are in good agreement with the radii calculated from the gear ratios of the powertrain under research. CONCLUSION: The developed powertrain model based on the drive wheel speed regulators can be used as a subsystem of a highly computationally efficient model of the tracked vehicle curvilinear motion.