Research On The Concomitant Movement And Power Characteristics Of High-Speed Tracked Vehicle

The high mobility of a tracked vehicle is reflected in its higher speed and stronger acceleration.Improvement of mobility plays an important role in promoting the high speed tracked vehicle battlefield survivability,carrying out a variety of combat missions.Improving the mobility of tracked vehicles requires more driving power.Therefore,it is necessary to improve the rated power of the propulsion system,that is,to improve the power of the engine.In addition,there is a need to increase the power transfer efficiency of the propulsion system,that is,to increase the power utilization.However,how to improve the power utilization of propulsion system is of great importance for further enhancing the mobility of tracked vehicle when the engine power is constant.When tracked vehicle driving on off-road conditions,besides the main movement with the forward direction,the other movement such as the vertical and pitch of the tracked vehicle will be generated due to uneven road surface and speed fluctuations,the other direction of the movement is called concomitant movement in this paper.Obviously,a part of the driving power will be consumed by the concomitant movement,and the power utilization of the propulsion system will be reduced.Therefore,this paper focuses on the concomitant motion and its power characteristics of tracked vehicle.First of all,the longitudinal-vertical dynamic coupling relationship of tracked vehicles is analyzed,and a coupled model that can reflect the longitudinal-vertical dynamic coupling characteristics of tracked vehicles is established.Besides,a Load wheel-Track-Road coupling model is built,which describes the pavement and remolding effect and load wheel-Track-Road interaction.Based on the coupling dynamics model of high-speed tracked vehicle,this paper further analyzes the power flow in high-speed tracked vehicle and obtains the calculation method of dynamic power and average power for high-speed tracked vehicle with the direction of motion.Then the power loss of concomitant movement in different road grades and different speed is calculated.The simulation results show that the power loss of the concomitant motion increases with the improvement of the pavement grade and the average longitudinal speed.When the total input power of the tracked vehicle is 200 kW,the concomitant motion power loss of tracked vehicles on the E-class road is about 7 times that of the C-class road,accounting for 43.3% of the total power.The concomitant motion power loss of tracked vehicles driving at 55km/h is about 5.7 times that of at 20km/h.Finally,this paper analyzes the conversion mechanism between longitudinal motion power and concomitant motion power in the course of tracked vehicle driving.The model of single-load-wheel is built to discuss the feasibility of using vehicle control method to regulate the concomitant motion power and improve the power utilization of the whole vehicle.The results show that under some conditions,the power required for motion control is equal to the power decreased due to the control action,when the strength of control action is lower than that of the power balance point,by concomitant motion power control can effectively improve the utilization rate of power vehicle.