The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway...The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway incorporates power generation,negative carbon technologies,and carbon trading.Technical,financial,and environmental models of decarbonisation technologies are established,capturing regional variations and time dynamic characteristics such as cost trends and carbon capture efficiency.The dynamic natures of characteristics pose challenges for using the cost-effective analyses approach to find the optimal decarbonisation pathway.To address this,we introduce a mixed-integer programming optimisation framework to find the decarbonisation pathway with minimum life cycle costs during the planning period.A case study for the optimal decarbonisation pathway of truck fleets in a South African coal mine is conducted to illustrate the applicability of the proposed model.Results indicate that the optimal decarbonisation pathway is significantly influenced by factors such as land cost,annual budget,and carbon trading prices.The proposed method provides invaluable guidance for transitioning towards a cleaner and more sustainable mining industry.展开更多
The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware i...The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware is the most appropriate for a specific application or application domain. In this paper we first extract a set of common and specific challenges that middlewares address, and group them according to the source domain they have originated within. These challenges are derived from a specific precision agriculture use-case based on the robotic fleet for weed control elaborated within the European project RHEA-robot fleets for highly effective agriculture and forestry management. Furthermore, the paper provides an analysis of a number of different middlewares and suggests a set of criteria for systemizing representative solutions. The aim of this analysis is to assist the process of finding an adequate middleware for a specific application domain.展开更多
Bus electrification is widely cited as a key technique to reduce carbon emissions and mit-igate climate change.In some Chinese cities,the electrification rate of buses has even reached 100%.However,compared with diese...Bus electrification is widely cited as a key technique to reduce carbon emissions and mit-igate climate change.In some Chinese cities,the electrification rate of buses has even reached 100%.However,compared with diesel buses(DBs),electric buses(EBs)cause scheduling problems during urban flash floods due to their limited wading performance.This study proposes a mixed EB-DB fleet strategy to mitigate bus fleet problems during urban flash floods.The difference in wading height thresholds between EBs and DBs is con-sidered in the fleet schedule.Utilizing a two-fleet strategy,the requisite number of DBs for bus depots is calculated.The mixed bus assignment problem is then solved by linear pro-gramming to establish the optimal dispatch scheme for the individual bus route.This study emphasizes the advantages of mixed bus fleets in emergency response,and contributes to improving urban transportation resilience.展开更多
针对中国民航高速增长与深度脱碳的矛盾,单一可持续航空燃料(SAF)路径面临技术天花板与需求增长抵消困境。构建融合混合整数规划(MIP)与系统动力学(SD)的FLEET(Flight Legs per Equivalent aircraft Turnover)模型,建立“微观运营-宏观...针对中国民航高速增长与深度脱碳的矛盾,单一可持续航空燃料(SAF)路径面临技术天花板与需求增长抵消困境。构建融合混合整数规划(MIP)与系统动力学(SD)的FLEET(Flight Legs per Equivalent aircraft Turnover)模型,建立“微观运营-宏观政策”双向反馈机制,量化多路径(SAF、新技术飞机及运营优化)协同减排效应。研究发现:SAF掺混比例在0~30%区间,每提升10%可减排12.7%;超30%后,边际效益显著递减,受原料缺口和PtL(Power-to-Liquid)技术瓶颈制约。强制掺混情景(SAF为50%+GDP年增速5.5%)下,2050年,碳排放较2019年仍增73%,其增幅受运输量波动(±0.5%)和SAF实际掺混效率(±5%)影响;最优组合情景(SAF为65%+新技术飞机40%+运营优化30%+市场机制15%)可实现2050年减排49.19%,单位政策激励减排量是单一SAF路径的2.3倍,形成技术互补、成本协同、减排乘数效应,证明了多路径协同的必要性。碳配额价格突破200元·t^(-1)是触发航司技术跃迁的关键阈值,响应存在主体与区域异质性(东部枢纽减排效率1.35 t·万元^(-1)大于西部支线0.87 t·万元^(-1))。本文揭示了中国民航减排需突破单一技术依赖,提出“技术-原料-政策”三阶段协同路线图(2025—2035年HEFA(Hydroprocessed Esters and Fatty Acids)规模化;2035—2045年原料多元化;2045—2050年政策深化),为分阶段政策设计和工程应用提供量化依据。展开更多
In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,...In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,and the speed control model is proposed from the perspective of vehicles themselves,to obtain a stable fleet with the same distance and speed.However,in this process,the initial condition of the vehicle,the traffic flow environment,and the efficiency of the fleet formation are less considered.Therefore,based on summarizing the existing fleet building model,this paper puts forward the rapid construction model and algorithm of a cooperative adaptive cruise control platoon fleet.One of the important goals of forming a team is to enter the team with the smoothest trajectory in the shortest time.Therefore,this chapter studies the trajectory optimization of the vehicle formation process from the perspective of vehicle dynamics.展开更多
Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics.It is possible to associate starting and end points of taxi trips with requirem...Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics.It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities.Previous research shows that due to service restrictions,boro taxis have typical customer destination locations on selected Saturdays:many drop-off clusters appear near the restricted zone,where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing.Detected crossings imply recent infrastructural modifications.We want to follow up on these results and add one additional group of commuters:Citi Bike users.For selected Saturdays in June 2015,we want to compare the destinations of boro taxi and Citi Bike users.This is challenging due to manifold differences between active mobility and motorized road users,and,due to the fact that station-based bike sharing services are restricted to stations.Start and end points of trips,as well as the volumes in between rely on specific numbers of bike sharing stations.Therefore,we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods.展开更多
A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet...A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system （MAS） model. A com- munication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol （CNP）. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.展开更多
Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. I...Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. In this study, the readiness ratio is proposed as a critical index in measuring the system's reliability. A well-established mathematical model adopting the optimization method of spare part allocation is also introduced. The objective is to minimize the number of each spare part while satisfying the fleet's system reliability. The fault tree analysis(FTA) is applied to analyze the system's failure logic and stratify the units on ship. As a result, the strategy of spare part sharing can be introduced in detail. The solution algorithm is developed, and the simulation experiments to obtain the key parameters are conducted. The proposed model and algorithm are applied to an actual fleet of two warships, and results show that the method above is feasible and can be directly applied into practice.展开更多
One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial...One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial role. Therefore, finding the optimal dispatching strategy for truck-shovel operations is extremely important. Dispatching strategies have been reported in the literature, but the comparison of these strategies is still missing. This paper illustrates the differences between the strategies by conducting a stochastic simulation study based on the data gathered from an actual mine. The findings underline the importance of the global vision in dispatching decisions.展开更多
A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a...A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a good schedule was obtained as the current best schedule by searching in this domain.Then,progressively narrower neighborhood search domains were constructed around the current best schedule to search for better schedules.The objective is to minimize the present value of waste removal costs over the mine life.The resulting schedule from this algorithm provides a complete fleet profile for each year over the mine life:the selected equipment models,the number of equipment units of each model,the age of each unit,as well as the quantity of waste removed.A numerical example of application was provided to demonstrate the feasibility and merits of the algorithm.展开更多
基金National Key R&D Program of China(Grant No.2021YFE0199000)National Natural Science Foundation of China(Grant No.62133015)National Research Foundation China/South Africa Research Cooperation Programme with Grant No.148762,and Royal Academy of Engineering Transforming Systems through Partnership grant scheme with reference No.TSP2021\100016.
文摘The fossil fuel powered mining truck fleets can contribute up to 80%of total emissions in open pit mines.This study investigates the optimal decarbonisation pathway for mining truck fleets.Notably,our proposed pathway incorporates power generation,negative carbon technologies,and carbon trading.Technical,financial,and environmental models of decarbonisation technologies are established,capturing regional variations and time dynamic characteristics such as cost trends and carbon capture efficiency.The dynamic natures of characteristics pose challenges for using the cost-effective analyses approach to find the optimal decarbonisation pathway.To address this,we introduce a mixed-integer programming optimisation framework to find the decarbonisation pathway with minimum life cycle costs during the planning period.A case study for the optimal decarbonisation pathway of truck fleets in a South African coal mine is conducted to illustrate the applicability of the proposed model.Results indicate that the optimal decarbonisation pathway is significantly influenced by factors such as land cost,annual budget,and carbon trading prices.The proposed method provides invaluable guidance for transitioning towards a cleaner and more sustainable mining industry.
文摘The past decade has witnessed a huge increase in the number of proposed middleware solutions for robotic fleets operating in unstructured environments. As a result, it has become difficult to decide which middleware is the most appropriate for a specific application or application domain. In this paper we first extract a set of common and specific challenges that middlewares address, and group them according to the source domain they have originated within. These challenges are derived from a specific precision agriculture use-case based on the robotic fleet for weed control elaborated within the European project RHEA-robot fleets for highly effective agriculture and forestry management. Furthermore, the paper provides an analysis of a number of different middlewares and suggests a set of criteria for systemizing representative solutions. The aim of this analysis is to assist the process of finding an adequate middleware for a specific application domain.
基金supported by the National Key R&D Program of China under Grant No.2023YFC3804004the Fundamental Research Funds for the Central Universities(Grant No.2022-5-YB-02).
文摘Bus electrification is widely cited as a key technique to reduce carbon emissions and mit-igate climate change.In some Chinese cities,the electrification rate of buses has even reached 100%.However,compared with diesel buses(DBs),electric buses(EBs)cause scheduling problems during urban flash floods due to their limited wading performance.This study proposes a mixed EB-DB fleet strategy to mitigate bus fleet problems during urban flash floods.The difference in wading height thresholds between EBs and DBs is con-sidered in the fleet schedule.Utilizing a two-fleet strategy,the requisite number of DBs for bus depots is calculated.The mixed bus assignment problem is then solved by linear pro-gramming to establish the optimal dispatch scheme for the individual bus route.This study emphasizes the advantages of mixed bus fleets in emergency response,and contributes to improving urban transportation resilience.
文摘针对中国民航高速增长与深度脱碳的矛盾,单一可持续航空燃料(SAF)路径面临技术天花板与需求增长抵消困境。构建融合混合整数规划(MIP)与系统动力学(SD)的FLEET(Flight Legs per Equivalent aircraft Turnover)模型,建立“微观运营-宏观政策”双向反馈机制,量化多路径(SAF、新技术飞机及运营优化)协同减排效应。研究发现:SAF掺混比例在0~30%区间,每提升10%可减排12.7%;超30%后,边际效益显著递减,受原料缺口和PtL(Power-to-Liquid)技术瓶颈制约。强制掺混情景(SAF为50%+GDP年增速5.5%)下,2050年,碳排放较2019年仍增73%,其增幅受运输量波动(±0.5%)和SAF实际掺混效率(±5%)影响;最优组合情景(SAF为65%+新技术飞机40%+运营优化30%+市场机制15%)可实现2050年减排49.19%,单位政策激励减排量是单一SAF路径的2.3倍,形成技术互补、成本协同、减排乘数效应,证明了多路径协同的必要性。碳配额价格突破200元·t^(-1)是触发航司技术跃迁的关键阈值,响应存在主体与区域异质性(东部枢纽减排效率1.35 t·万元^(-1)大于西部支线0.87 t·万元^(-1))。本文揭示了中国民航减排需突破单一技术依赖,提出“技术-原料-政策”三阶段协同路线图(2025—2035年HEFA(Hydroprocessed Esters and Fatty Acids)规模化;2035—2045年原料多元化;2045—2050年政策深化),为分阶段政策设计和工程应用提供量化依据。
文摘In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,and the speed control model is proposed from the perspective of vehicles themselves,to obtain a stable fleet with the same distance and speed.However,in this process,the initial condition of the vehicle,the traffic flow environment,and the efficiency of the fleet formation are less considered.Therefore,based on summarizing the existing fleet building model,this paper puts forward the rapid construction model and algorithm of a cooperative adaptive cruise control platoon fleet.One of the important goals of forming a team is to enter the team with the smoothest trajectory in the shortest time.Therefore,this chapter studies the trajectory optimization of the vehicle formation process from the perspective of vehicle dynamics.
文摘Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics.It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities.Previous research shows that due to service restrictions,boro taxis have typical customer destination locations on selected Saturdays:many drop-off clusters appear near the restricted zone,where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing.Detected crossings imply recent infrastructural modifications.We want to follow up on these results and add one additional group of commuters:Citi Bike users.For selected Saturdays in June 2015,we want to compare the destinations of boro taxi and Citi Bike users.This is challenging due to manifold differences between active mobility and motorized road users,and,due to the fact that station-based bike sharing services are restricted to stations.Start and end points of trips,as well as the volumes in between rely on specific numbers of bike sharing stations.Therefore,we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods.
文摘A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The mainte- nance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system （MAS） model. A com- munication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol （CNP）. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.
文摘Allocation of fleet's spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship's service level highly relies on the maintenance logistics' level. In this study, the readiness ratio is proposed as a critical index in measuring the system's reliability. A well-established mathematical model adopting the optimization method of spare part allocation is also introduced. The objective is to minimize the number of each spare part while satisfying the fleet's system reliability. The fault tree analysis(FTA) is applied to analyze the system's failure logic and stratify the units on ship. As a result, the strategy of spare part sharing can be introduced in detail. The solution algorithm is developed, and the simulation experiments to obtain the key parameters are conducted. The proposed model and algorithm are applied to an actual fleet of two warships, and results show that the method above is feasible and can be directly applied into practice.
文摘One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial role. Therefore, finding the optimal dispatching strategy for truck-shovel operations is extremely important. Dispatching strategies have been reported in the literature, but the comparison of these strategies is still missing. This paper illustrates the differences between the strategies by conducting a stochastic simulation study based on the data gathered from an actual mine. The findings underline the importance of the global vision in dispatching decisions.
基金Projects(51474049,51674062)supported by the National Natural Science Foundation of ChinaProject(51604061)supported by the National Science Foundation for Young Scientists of China+3 种基金Projects(201202075,2014020040)supported by the Liaoning Natural Science Founds,ChinaProject(LZ2014020)supported by the Liaoning Province’s Key Laboratory Construction,ChinaProject(20130042110012)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(F14-231-1-07)supported by the Shenyang Technical Plan Project,China
文摘A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a good schedule was obtained as the current best schedule by searching in this domain.Then,progressively narrower neighborhood search domains were constructed around the current best schedule to search for better schedules.The objective is to minimize the present value of waste removal costs over the mine life.The resulting schedule from this algorithm provides a complete fleet profile for each year over the mine life:the selected equipment models,the number of equipment units of each model,the age of each unit,as well as the quantity of waste removed.A numerical example of application was provided to demonstrate the feasibility and merits of the algorithm.
