Research On Driving Characteristics Of Belt Conveyor Based On Virtual Prototype Technology

The belt conveyor is a rigid-flexible hybrid system integrating mechatronics and hydraulics in the transportation industry.With the continuous increase in transportation requirements,the distance and speed of the conveyor have become larger,and the conventional static research thinking has appeared drawbacks,and it is impossible to study the actual complex dynamic characteristics during the start-up process.When the transportation volume becomes large,for decreasing the load of the motor,the multi-motor drive is adopted.Due to the viscoelastic characteristics of the belt and the traditional direct drive mode of the motor,a complex dynamic tension wave is generated in the conveyor belt and impacts some components.The unevenness of the motor leads to unbalanced power between the motors,unable to work together or even accidents.In the process of researching and analyzing the dynamic characteristics of the conveyor,the real-time variability of the load in practice is not considered,and the real dynamic characteristics of the conveyor could not be well reflected.With respect to the above questions,in this study,the motor frequency conversion vector control principle and the multi-body dynamics theory of VPT were combined to establish the head single and double drive conveyor model;using the idea of co-simulation,Based on the Harrison starting curve,the motor drove the conveyor,and the simulation analysis of different starting conditions of no-load,constant load and real-time variable load was carried out.The main research:(1)Firstly,the working performance of the conveyor was analyzed,and then the main running resistance and driving force of the conveyor were calculated,so as to select the appropriate motor power and model.The tension value at the special point of the belt under the full load condition of double drive conveyor was calculated by point by point method.The change law of the tension along the conveying direction is analyzed,which provides a certain reference for the later simulation results.Based on the theoretical analysis of the mechanical properties of the conveyor belt,the correctness of the mechanical properties of the belt is verified through the design of tensile experiments.(2)Based on the research and analysis of the driving mode and dynamic mathematical model of the motor,the vector frequency conversion control strategy was established,and the overall simulation model of the conveyor driving motor was built in MATLAB / Simulink,The results reflect that: the starting current of the motor is controlled in a reasonable range;The motor speed can reach the target speed quickly;The motor torque and load torque can be balanced and stable.So the variable frequency soft start of the motor can be realized.(3)Based on the theory of multi-body dynamics,the virtual prototype model of the conveyor with single and double driving hammers was established in Recudryn.Based on the simulation and analysis of multiple motor cooperative control strategies,a dual motor model of cross coupling control strategy was established.Based on the idea of Simulink and Recur Dyn co-simulation,the dynamic characteristics and power balance of head single and double drive conveyor under different conditions of no-load,constant load and time-varying load were simulated and analyzed.The results show that: in the driving process of different working conditions,the speed of the conveyor can reach the given speed according to the harrsion starting curve.The change law of speed and tension is analyzed,which is proved to be in line with the reality.The main and secondary motor speed and torque output are basically synchronous,and the desired results are achieved.Under two different time-varying load conditions,it is proved that the impact of the material has a greater impact on the change of belt tension than the constant load.