Powertrain System Collaborative Control Of Dual-motor Independent-driving Articulated Electric Vehicles Used In Coal Mine

The vehicle of two-axle with independent drive motors and articulated steering has great potential,which is driven through front and rear axle,and has the characteristic of good pavement adaptability,good maneuvering and flexibility,zero emission,so as to adapt to the complex environment of the coal mine.The structure of front and rear motors driving and articulated steering of the vehicle is very suitable for the heavy vehicles of coal mine trackless auxiliary transport.Because of the configuration of articulated steering,the dynamic characteristics of the vehicle is different from that of common whole body structure.In order to ensure driving the vehicle safely and efficiently,the control strategy of the vehicle under the circumstances of coal mine and in the using conditions is important and necessary increasingly.With the plant of the mine vehicle of two-axle with independent drive motor and articulated steering,dynamics modeling and torque distribution control of the front and rear driving motors are concentrated on.Dynamic modeling of the mine vehicle of two-axle with independent drive motor and articulated steering is accomplished.Firstly,the whole body of the vehicle is simply considered as two bodies connected with each other by articulated mechanism,and with the selection of appropriate coordinates,based on Newton vector method,the kinematics and dynamics equations of the vehicle are derived on.Further,the tire slip ratio,the side angle,and the vertical tire load are derived on.By consideration of the nonlinear characteristic of the tire,the tire model based on the GIM theory is combined with the vehicle model.Finally,the seven degrees of freedom model of the vehicle is built.And through simulation,the model is analyzed and verified correct.The mass,centroid position,and road slope of the auxiliary transport vehicles of coal mine is variable,so parameter estimation is engaged in.Because the torque and the rotating speed of the driving motor can be measured accurately and easily,in consideration of the design and operation environment of the vehicles,a method which decouples the parameter estimation of the vehicle mass and road slope by using of simplified dynamic model is put forward.The dynamic model of the vehicle which is used to estimate the parameter of mass and road slope is established.Based on recursive least squares method the parameter of mass is identified.Through offline fit,the centroid position of the front body of the vehicle and the relationship between the moment of inertia of the front body and the whole vehicle mass is described,so that these parameters are obtained after the mass parameter is identified.And then the road slope is estimated through recursive least squares method with forgetting factor.Finally simulation shows that the estimation method of mass and road slope is correct and effective.Traction control of the vehicle of two-axle with independent drive motor and articulated steering is discussed.According to the structure and the use condition of the vehicle,the design requirements of traction control are analyzed.Base on sliding mode control,the drive anti-slip controller for the vehicle under circumstances of going straight is synthesized.Considering the general situation of the vehicle turning,the drive anti-slip controllers for the four tires are discussed separately,and then the outputs of the front axle motor and the rear one are determined.Further regarding the drive anti-slip control algorithm as essential,the traction integrated optimization control of the vehicle of two-axle with independent drive motor and articulated steering is put forward,which distributes drive torque dynamically on three levels.Firstly,on level one,the drive torque of the vehicle is distributed according to the vertical tire load in proportion.Secondly,on level two,the drive torque is distributed through comparing the calculation of the drive anti-slip controller with the distribution results of level one.Thirdly,on level three,the drive torque is adjusted dynamically and optimized.Simulation of the traction control shows that on one hand,when the drive anti-slip control being applied to the vehicle,the tire slipping is not happened and the tire drive forces are ensured simultaneously,on the other hand,when the traction integrated optimization control being applied to the vehicle,the drive torque of both the front axle motor and the rear one is adjusted dynamically and optimized to match the vehicle situation,as a result the drive torque is utilized efficiently and the drive performance of the vehicle is improved effectively.The joint simulation environment of ADAMS-Matlab/Simulink is established.Under ADAMS environment,the dynamic model of the articulated vehicle is constructed.Under Matlab/Simulink environment the traction controller of the vehicle is built.And the feedback loop works through the input and output interface of the module.The joint simulation of the control system is finished,and the result shows consistency with that of the numerical analysis.The dynamic modeling and traction control design is verified.The real vehicle experiment of drive anti-slip control is designed and realized.The torque distributing controller is developed to implement the control algorithm.The vehicle bus based test system is designed,which is used to supervise the real-time experiment procedure and record the experiment data.Drive performance of the vehicle with drive anti-slip control and the vehicle without drive anti-slip control is separately test through the experiment.The results show that with drive anti-slip control applied,the slip ratio of the driving wheel of the vehicle remains near the target value,and acceleration characteristic of the vehicle is improved.