Research On Mechanical System Of Mine Rail Auxiliary Transportation Container Transfer Robot

With the strong promotion of coal mine intelligent construction by the government,the efficiency,safety and level of intelligence in coal mine mining have been continuously improved.However,due to factors such as terrain conditions and performance limitations of transportation equipment,traditional underground auxiliary transportation still has problems such as discontinuous transportation,many reloading links,high labor intensity and low automation level.Therefore,aiming at the problem of container reloading between the electric locomotive and the monorail crane in the rail auxiliary transportation,this thesis innovatively designed a container transfer robot,and studied and analyzed its mechanical system,which is of great significance to promote the development goal of "continuous,standardized and unmanned" auxiliary transportation in coal mines.First of all,by analyzing the operating environment of the transfer robot during the auxiliary transportation process in the underground track,design requirements for the transfer robot were proposed,and selection of the lifting and fixing scheme for the container was carried out,resulting in the overall structure of the transfer robot.The container reloading robot mechanical system mainly includes three parts: monorail spreader,standardized loading container and standardized loading flatbed.Based on the operating environment of the transfer robot,an automatic container transfer strategy and a ground-to-air reloading process are proposed.Then,the structural design of the monorail spreader,standard container and flatbed truck is carried out,and the hydraulic system of the spreader is designed,selected and calculated.In the finite element software,the mechanical system of the robot is analyzed statically,and the static analysis is carried out on the unbalanced load condition of the spreader,the uniform lifting and braking condition of the container,and the bending and torsion condition of the flat frame.The results show that the structural safety factor of each component of the robot mechanical system is above 1.5,which meets the requirements of engineering use.Furthermore,the running stability of the fully loaded flatbed mine truck was analyzed,and the results showed that the lateral and longitudinal stability coefficients of the fully loaded flatbed truck exceeded 1.5,which meet the design requirements.At the same time,the collision impact force on the flatbed frame due to the deceleration and braking of the fully loaded vehicle group and the traction impact force generated by the electric locomotive accelerating uphill are analyzed.The results show that the flatbed structure can meet the requirements in both cases.Through the modal analysis of the mechanical system and the transient dynamic analysis of the spreader,it is concluded that the dynamic performance of the mechanical system is good.Finally,according to the working characteristics and performance analysis results of the spreader in the reloading robot,a multi-objective optimal design method of the spreader structure based on response surface is proposed by using the experimental design,surrogate model and multi-objective optimization method.The design variables were analyzed through the sensitivity theory,and five size parameters were finally selected as the optimal design variables.The LHS sampling method was used to obtain sample points and response values,and three approximate models of standard quadratic polynomial,Kriging and neural network were established for comparison and verification.Based on the Kriging approximate model,aiming at the minimum spreader mass and stress-strain,the variant genetic algorithm NSGA-II is used for multi-objective optimization,and the optimal design scheme is obtained and verified.The results show that the accuracy of the Kriging approximate model is higher.Compared with the original spreader,the performance of the optimized spreader meets the requirements.The total mass of the spreader is reduced by 77.1kg and the drop rate is 15.3%.The optimization effect is better.The thesis has 96 pictures,21 tables,and 90 references.