Scheduling And Operation Optimization Of The Wheel Loader/Truck Loading And Transportation Cycle

The loading and transportation site with wheel loaders and trucks is a typical site of construction machines.Because of the characteristics of this site,such as multiple mobile machines working together and the complex transportation environment,it is necessary to study the operation strategy.In the operation,both fuel consumption and productivity are important measurements.In terms of fuel consumption,compared with on-road vehicles,construction machines generally consume more fuel due to high load and complex transportation environment.In order to save on fossil fuels,solve energy shortages and environmental problems,operators need to reduce fuel consumption through operation strategy;In terms of productivity,improving the productivity through operation strategy is conducive to reducing the operating cost of the site.Better fuel economy sometimes means reduced productivity while higher productivity requires more powerful powertrain and thus consumes more fuel.In order to balance the fuel consumption and productivity,this study proposed a comprehensive criteria taking both the fleet fuel consumption and the fleet productivity into account which is the fleet operating cost and used operation strategy to achieve a balance between fleet fuel consumption and fleet productivity by minimizing fleet operating cost.Focused on the loading and transportation site with wheel loaders and trucks,this study takes the fleet configuration(number of trucks and number of wheel loaders)and fleet operating parameter(truck loading time)as variables in the operation process,and analyzed the effect of the variables on fleet fuel consumption,fleet productivity and fleet operating cost;In order to obtain trucks and wheel loaders position at different time,a dispatching management strategy for construction machines has been studied;The fuel consumption of wheel loaders and trucks were obtained through simulation studies,and operation quantification method which quantifies fleet fuel consumption,fleet productivity and fleet operating cost were developed;The operation decision method was presented to achieve a balance between fleet fuel consumption and fleet productivity by minimizing fleet operating cost.The content of each chapter are as follows:In the first chapter,the research background was introduced,and the current development status of construction machines fuel consumption,productivity and operating cost was investigated.The importance of the operation strategy for construction machines and the significance of this study were explained,and finally the research content were introduced.In the second chapter,the loading and transportation site with wheel loaders and trucks was introduced,and the operation strategy for construction machines has been studied.The operation strategy process was introduced,including fleet configuration and fleet operating parameter research,dispatching management strategy research,operation quantification method research and operation decision method research.The construction machines dispatching management strategy was introduced,and operation quantification method are given,in which the fleet fuel consumption is obtained by means of modeling and simulation.In the third chapter,the construction machines powertrain systems were modeled and its controllers were designed.The mathematical models of the main components were built and the control strategy was developed based on the optimal engine torque and speed.In the fourth chapter,the research on fuel consumption simulation of construction machines has been carried out.The simulation model of construction machines powertrain systems were built in MATLAB/Simulink,and the setting method of working conditions were given,including the construction machines speed profiles setting and the working hydraulic system pressure and flow setting.The construction machines powertrain parameters were given and the construction machines fuel consumption under different fleet configuration and fleet operating parameter were obtained.In the fifth chapter,according to the operation quantification method described in the second chapter,the fleet fuel consumption,the fleet productivity and the fleet operating cost under all fleet configuration and fleet operating parameter were calculated and analyzed.Through the analysis of the quantification results,the optimal fleet configuration and fleet operating parameter were given to minimize the fleet operating cost,and the balance between fleet fuel consumption and fleet productivity was achieved.In the sixth chapter,the main content and shortcoming of this paper was summarized,the future work was given.