The highway on-ramp merging area is a common bottleneck prone to traffic congestion and accidents.With the current trajectory and advancements in automotive technology,intelligent vehicle infrastructure cooperative co...The highway on-ramp merging area is a common bottleneck prone to traffic congestion and accidents.With the current trajectory and advancements in automotive technology,intelligent vehicle infrastructure cooperative control based on connected and automated vehicles(CAVs)is a fundamental solution to this problem.While much existing research focuses solely on ramp merging control in single-lane highway scenarios,there is more than one main lane in the actual highway environment.Thus,this paper proposes a dual-clutch longitudinal-lateral cooperative planning model,inspired by the principle of dual-clutch transmission,to address this gap.Besides,considering the impact of communication delay on control effects within the internet of vehicles,the paper proposes a system delay prediction model,which integrates the adaptive Kalman filter algorithm,the elitist non-dominated sorting genetic algorithm based on imitation learning,and the radial basis function neural network.The delay predicted dual-clutch on-ramp merging control model(DPDM)applied to two-lane highways for CAVs makes up of these two models above.Then,the performance of the DPDM is analyzed under different traffic densities on two-lane highways through simulation.The findings underscore the DPDM's pronounced comprehensive advantages in enhancing group vehicle safety,expediting and stabilizing merging processes,optimizing traffic flow speed,and economizing fuel consumption.展开更多
The service time and time headway of the vehicles are used to define the equivalency factor of different vehicle classes at the toll plaza.Both the service time and time headway are point measures and do not account f...The service time and time headway of the vehicles are used to define the equivalency factor of different vehicle classes at the toll plaza.Both the service time and time headway are point measures and do not account for the system delay(time difference when a vehicle enters the queue and leaves the tollbooth)caused to the vehicle.The present study aims to quantify the system delay incurred to the vehicles at electronic toll collection(ETC)lanes under mixed traffic conditions using a microsimulation approach.Field data collected from one toll plaza located on a National Highway are used for simulation model generation.A new terminology called system delay-based toll equivalency factor(DTEF)is introduced to convert the different vehicle classes into equivalent passenger cars.The DTEF variation for different approach volumes and heavy commercial vehicle(HCV)compositions were checked at different ETC penetration levels.A total of 288 scenarios have been worked out,and simulation runs have been made for all such scenarios to obtain the DTEF values.The average DTEF value of HCV was obtained as 2.20.Further,it is found that with an increase in approach volume and HCV share in the traffic stream,the DTEF value increases.The outcome of the present study will be useful to field practitioners and engineers to determine the capacity in equivalent DTEF/hr and level of service of a toll plaza in terms of system delay.展开更多
As the sampling rates of the inner loop and the outer loop of the target tracking control system are different,a typical digital multi-rate control system was formed.If the traditional single-rate design method was ap...As the sampling rates of the inner loop and the outer loop of the target tracking control system are different,a typical digital multi-rate control system was formed.If the traditional single-rate design method was applied,the low sampling rate loop will seriously impact the dynamical characteristic of the system.After analyzing and calculating the impact law of the low sampling rate loop to the bandwidth and the stability of the tracking system,a kind of multi-rate control system design method was introduced.Corresponding to the different sampling rates of the inner loop and the outer loop,the multi-rate control strategy was constituted by a high sampling rate sub-controller and a low sampling rate sub-controller.The two sub-controllers were designed separately and connected by means of the sampling rate converter.The low sampling rate controller determined the response rapidity of the system,while the high sampling rate controller applied additionally effective control outputs to the system during a sampling interval of the low sampling rate controller.With the introduced high and low sampling rates sub-controllers,the tracking control system can achieve the same performance as a single-rate controller with high sampling rate,yet it works under a much lower sampling rate.The simulation and experimental results show the effectiveness of the introduced multi-rate control design method.It reduces the settling time by 5 times and the over shoot by 4 times compared with the PID control.展开更多
Application of delayer in audio system.Delayer is one of important equipment in audio system. In this article, it firstly introduces the type of delayer, and then accounts for the function of delayer: making sound cor...Application of delayer in audio system.Delayer is one of important equipment in audio system. In this article, it firstly introduces the type of delayer, and then accounts for the function of delayer: making sound correspond to image by way of Hass Effect; eliminating echo and improving clarity of audio system; producing simulating stereo effect and chorus effect.展开更多
As parking scenarios become narrower,vehicles often cannot enter the parking lot in one step.This paper presents a multimaneuver vertical parking trajectory planning and tracking control strategy based on a predefined...As parking scenarios become narrower,vehicles often cannot enter the parking lot in one step.This paper presents a multimaneuver vertical parking trajectory planning and tracking control strategy based on a predefined geometric set method.Firstly,to minimize the space required for parking,a multi-constraint nonlinear programming path function model based on arc-line-arc is established to find the key points of the path for vehicles to enter the parking space while considering the vehicle structure and road boundary constraints comprehensively.Secondly,the double-S speed planner carries out the speed planning.Finally,based on the vehicle–road deviation prediction model,an MPC lateral motion controller with the steering system delay compensation is established.A vehicle speed-tracking controller is designed on the basis of PID control.The proposed parking planning and control strategy is then tested on the autonomous vehicle platform to verify its feasibility and effectiveness.The results demonstrate that the proposed method can solve the problem of multi-maneuver vertical parking trajectory planning and tracking control in narrow environments.Under the action of the lateral and longitudinal controller,the vehicle can be safely and accurately guided to track the parking trajectory into the parking space.The lateral error is controlled within 0.054 m,and the heading deviation is controlled within 0.02 rad.展开更多
文摘The highway on-ramp merging area is a common bottleneck prone to traffic congestion and accidents.With the current trajectory and advancements in automotive technology,intelligent vehicle infrastructure cooperative control based on connected and automated vehicles(CAVs)is a fundamental solution to this problem.While much existing research focuses solely on ramp merging control in single-lane highway scenarios,there is more than one main lane in the actual highway environment.Thus,this paper proposes a dual-clutch longitudinal-lateral cooperative planning model,inspired by the principle of dual-clutch transmission,to address this gap.Besides,considering the impact of communication delay on control effects within the internet of vehicles,the paper proposes a system delay prediction model,which integrates the adaptive Kalman filter algorithm,the elitist non-dominated sorting genetic algorithm based on imitation learning,and the radial basis function neural network.The delay predicted dual-clutch on-ramp merging control model(DPDM)applied to two-lane highways for CAVs makes up of these two models above.Then,the performance of the DPDM is analyzed under different traffic densities on two-lane highways through simulation.The findings underscore the DPDM's pronounced comprehensive advantages in enhancing group vehicle safety,expediting and stabilizing merging processes,optimizing traffic flow speed,and economizing fuel consumption.
基金funded by the DST-DAAD project“Warrants for Automation of Toll Plazas Under Mixed Traffic Conditions.”(Project Number:–DST/INT/DAAD/P-14/2020).
文摘The service time and time headway of the vehicles are used to define the equivalency factor of different vehicle classes at the toll plaza.Both the service time and time headway are point measures and do not account for the system delay(time difference when a vehicle enters the queue and leaves the tollbooth)caused to the vehicle.The present study aims to quantify the system delay incurred to the vehicles at electronic toll collection(ETC)lanes under mixed traffic conditions using a microsimulation approach.Field data collected from one toll plaza located on a National Highway are used for simulation model generation.A new terminology called system delay-based toll equivalency factor(DTEF)is introduced to convert the different vehicle classes into equivalent passenger cars.The DTEF variation for different approach volumes and heavy commercial vehicle(HCV)compositions were checked at different ETC penetration levels.A total of 288 scenarios have been worked out,and simulation runs have been made for all such scenarios to obtain the DTEF values.The average DTEF value of HCV was obtained as 2.20.Further,it is found that with an increase in approach volume and HCV share in the traffic stream,the DTEF value increases.The outcome of the present study will be useful to field practitioners and engineers to determine the capacity in equivalent DTEF/hr and level of service of a toll plaza in terms of system delay.
基金Project(51105372) supported by the National Natural Science Foundation of ChinaProject(JC12-03-01) supported by the Research Plan of National University of Defense Technology,China
文摘As the sampling rates of the inner loop and the outer loop of the target tracking control system are different,a typical digital multi-rate control system was formed.If the traditional single-rate design method was applied,the low sampling rate loop will seriously impact the dynamical characteristic of the system.After analyzing and calculating the impact law of the low sampling rate loop to the bandwidth and the stability of the tracking system,a kind of multi-rate control system design method was introduced.Corresponding to the different sampling rates of the inner loop and the outer loop,the multi-rate control strategy was constituted by a high sampling rate sub-controller and a low sampling rate sub-controller.The two sub-controllers were designed separately and connected by means of the sampling rate converter.The low sampling rate controller determined the response rapidity of the system,while the high sampling rate controller applied additionally effective control outputs to the system during a sampling interval of the low sampling rate controller.With the introduced high and low sampling rates sub-controllers,the tracking control system can achieve the same performance as a single-rate controller with high sampling rate,yet it works under a much lower sampling rate.The simulation and experimental results show the effectiveness of the introduced multi-rate control design method.It reduces the settling time by 5 times and the over shoot by 4 times compared with the PID control.
文摘Application of delayer in audio system.Delayer is one of important equipment in audio system. In this article, it firstly introduces the type of delayer, and then accounts for the function of delayer: making sound correspond to image by way of Hass Effect; eliminating echo and improving clarity of audio system; producing simulating stereo effect and chorus effect.
基金support of the National Natural Science Foundation of China(Grant 52372412)the Technology Innovation and Application Development Special Project of Chongqing(CSTB2022TIAD-DEX0014).
文摘As parking scenarios become narrower,vehicles often cannot enter the parking lot in one step.This paper presents a multimaneuver vertical parking trajectory planning and tracking control strategy based on a predefined geometric set method.Firstly,to minimize the space required for parking,a multi-constraint nonlinear programming path function model based on arc-line-arc is established to find the key points of the path for vehicles to enter the parking space while considering the vehicle structure and road boundary constraints comprehensively.Secondly,the double-S speed planner carries out the speed planning.Finally,based on the vehicle–road deviation prediction model,an MPC lateral motion controller with the steering system delay compensation is established.A vehicle speed-tracking controller is designed on the basis of PID control.The proposed parking planning and control strategy is then tested on the autonomous vehicle platform to verify its feasibility and effectiveness.The results demonstrate that the proposed method can solve the problem of multi-maneuver vertical parking trajectory planning and tracking control in narrow environments.Under the action of the lateral and longitudinal controller,the vehicle can be safely and accurately guided to track the parking trajectory into the parking space.The lateral error is controlled within 0.054 m,and the heading deviation is controlled within 0.02 rad.
