Dynamic Torque Distribution Of Distributed Articulated Vehicle Based On Slip Rate Control

With the development of coal mine in the field of large mining height and thin coal seam,the existing truck has been unable to meet the transportation requirements of large mining height working face equipment and the passing requirements of thin coal seam."Mine wheel edge distributed drive" is a very potential drive mode,with the advantages of compact structure,small turning radius,independent motor control,etc.,can adapt to the needs of the operation in the narrow roadway with muddy wet and many bends.However,because there is no finite slip differential,when the wheel is poorly attached to the road surface and the torque distribution is too large,it will slip excessively,resulting in insufficient power and reduced operating efficiency.At present,the torque distribution is mainly based on equal torque and fixed proportion,which can not be dynamically adjusted.Therefore,the topic proposes to realize dynamic torque distribution based on real-time slip rate control,ensure that the wheels can output ideal torque according to the attachment,and achieve the best vehicle power output,which is of great significance to improve the efficiency of coal mine auxiliary transportation.Aiming at this problem,this paper conducts dynamic modeling and analysis of distributed drive articulated vehicles,and realizes dynamic distribution of four-wheel torque through real-time monitoring and control of slip rate.The main contents are as follows:(1)Mathematical modeling for distributed drive articulated vehicles.Firstly,the vehicle dynamics equation is derived by analyzing the force in XY direction of the articulated vehicle with variable load,and the load change and centroid transfer of the front vehicle body are considered.Secondly,the relationship between the vertical load distribution of the tire and the hinge Angle is deduced by analyzing the force in the Z direction.The GIM tire model was used to analyze the nonlinear characteristics of the tire.Finally,the seven-degree-of-freedom vehicle dynamics model is established,and the correctness of the model is verified by Simulink simulation.(2)Research is carried out on the problem that it is difficult to obtain accurate data of the speed of articulated vehicles in underground Wells.Considering the special form of articulated vehicle,the relationship between the longitudinal moving speed of wheel center and the longitudinal moving speed of the front and rear center of mass of vehicle body is analyzed.Based on limiter filter and correction compensation,a method of speed measurement of distributed drive articulated vehicle for mining is proposed.A vehicle speed estimation model was built in Simulink,and the vehicle speed measured from the driving wheel was compared with the estimated vehicle speed through the vehicle speed test.The error was 2%～3%,which verified the effectiveness of the vehicle speed estimation method.(3)Research on drive anti-slip controller for distributed drive articulated vehicles.Traditional PID control is not suitable for strong nonlinear system.Genetic algorithm is used to optimize PID to realize the adaptive adjustment of control parameters.A sliding rate controller based on GA-PID is designed and built.The traditional PID control may fail when the hinged Angle changes,but GA-PID control can be adapted to different hinged angles,which solves the defect that the traditional PID cannot automatically adjust the control parameters in real time.Through simulation under noload,full-load and variable load conditions,the slip rate can be effectively controlled around 0.2.(4)A three-level optimal dynamic torque distribution strategy for distributed drive articulated vehicles is proposed.First,the tire vertical load is identified and the torque is distributed once according to the load proportion.Secondly,combined with the torque of the slip rate controller,the smaller value of the two is used for secondary distribution.Then the excess torque of the drive limiter motor is compensated to the underdrive motor for three times of torque distribution.Compared with other torque distribution methods,the advantages of this method are verified.Finally,the real-time performance and effectiveness of this method are verified by real vehicle experiments..