Simulated Road Research Articles

Multiagent reinforcement learning for autonomous driving in traffic zones with unsignalized intersections

In this work we present a multiagent deep reinforcement learning approach for autonomous driving vehicles that is able to operate in traffic networks with unsignalized intersections. The key aspects of the proposed study are the introduction of route-agents as the main building block of the system, as well as a collision term that allows the cooperation among vehicles and the construction of an efficient reward function. These have the advantage of establishing an enhanced collaborative multiagent deep reinforcement learning scheme that manages to control multiple vehicles and navigate them safely and efficiently-economically to their destination. In addition, it provides the beneficial flexibility to lay down a platform for transfer learning and reusing knowledge from the agents’ policies in handling unknown traffic scenarios. We provide several experimental results in simulated road traffic networks of variable complexity and diverse characteristics using the SUMO environment that empirically illustrate the efficiency of the proposed multiagent framework.

Chemical Leaching from Tire Wear Particles with Various Treadwear Ratings.

Physical friction between a tire and the road surface generates tire wear particles (TWPs), which are a source of microplastics and particulate matter. This study investigated the trends of chemical leaching from TWPs depending on the treadwear rating of the tire. A road simulator was used to produce TWPs from tires with various treadwear ratings. Liquid chromatography–tandem mass spectrometry was used to analyze the chemical leaching from TWPs, with a particular focus on benzothiazole and its derivative 2-hydroxy benzothiazole. However, chemical mapping via high-resolution tandem mass spectrometry detected another derivative: 2-mercaptobenzothiazole. The benzothiazole groups were observed to have different leaching tendencies, implying that using benzothiazole as a marker compound may lead to incorrect TWP quantitation. The results of this research also suggest that the ecotoxicological influence of TWPs can vary with the treadwear rating of a tire.

Modeling of Virtual Simulation Road for Autonomous Driving based on HD maps

Modeling of Virtual Simulation Road for Autonomous Driving based on HD maps

Beam controlled lighting design: An approach towards optimization of road lighting design

LED based street lighting has been introduced everywhere for energy saving aspect. The Optical Control of LED is very much possible with change of beam angles. This beam-angle based switching of LED based street lighting installations is a new area to be explored. Global research says LED is an energy saving light source. But during low or off traffic hours, portion of LED arrays of a luminaires may be switched on/off on the basis of beam-angle. The light level is reduced. The ‘beam-angle switching’definitely ensures energy saving, but the investigation of the human performance under this condition is also necessary. There is no such evidence available in favour of the effectiveness of ‘beam-angle switching’ on human performance. In this paper an experimentation based studies have been conducted to identify the driver’s response during the object detection under different lighting conditions as PRO, COUNTER and FULL GLOW of a LED luminaire. The visibility study has been carried out in a simulated road to prove the effectiveness of this beam-angle based switching from the human performance as well as energy saving point of view.

Assessing Coastal Road Flood Risk in Arctic Alaska, a Case Study from Hooper Bay

Rising waters and land subsidence are increasing relative sea levels in western and northern Alaska, forcing communities to relocate or armor in place. To appropriately plan and make equitable decisions, there is a need to forecast the risk of flood exposure in coastal Alaskan communities and to evaluate methods to mitigate that risk. This paper conducts use-inspired science to evaluate the current and future flood exposure of roads in Hooper Bay, Alaska, proposes a unit cost of flood exposure to estimate the cost of flooding, and compares various mitigation efforts including elevating roads and building dikes. Nine historic storms and their associated flood depths were subject to return-period analysis and modeled for several sea level rise scenarios. Based on the simulated road flood exposure (km hours/storm), and the storm-return period, an annual flood exposure (km hours/year) was computed. Then, the unit cost of flood exposure (USD/km hours) was determined as the ratio of the cost of flood mitigation (USD/year) to the annual flood exposure mitigated by the project. The analysis found that the unit cost of flood exposure, in conjunction with flood exposure calculations, does provide an approximate flood risk calculation, though a unitized cost of flood exposure needs to be divided into lump sum costs and materials costs. The analysis also found that dikes may be a more cost-effective alternative than road elevation. The flood risk calculation, based on the unit cost of flood exposure, could be made for all of the communities in a given region to identify those communities that face a high flood risk. Furthermore, if one divides the unit cost of flood exposure by the population, one obtains a cost/benefit ratio that potentially could be used to prioritize flood mitigation work.

A Comparison Between Experimental Life Road Simulation and Computational Fluid Dynamics and Fluid Structure Interaction for Sedan Car

The flow around road vehicle is characterized by regions of separation that affect the aerodynamics and performance of the vehicle due to the variations in the negative pressure zones. In this work, Computational fluid dynamics and Fluid-structure interaction models are developed to simulate the aerodynamic performance of a sedan car. An experimental live road simulation is conducted to validate the performance and the accuracy of the presented models. The experimental setup was organized on a sedan car using tufts and digital cameras for flow visualization. Four cruise speeds of 40, 60, 80, and 100 km/hr are used. At low cruise speed the FSI simulation can attain the required result for indicating the negative pressure zones, created behind the car tail and mostly close to the car body. The experimental results appear to visualize the movement of the tufts that attained a certain angle corresponding to the flow speed, which matches the distribution of negative pressure and wake area. At high cruise speed the CFD simulation elucidated the separation area where the negative pressure created behind the car tail matched the movement of the tufts which attained an approximate straight angle corresponding to the flow speed having a swirling movement.

Optimal Energy Efficient Control of Pure Electric Vehicle Power System Based on Dynamic Traffic Information Flow

To improve the energy efficiency and driving condition adaptability of pure electric vehicles (EVs) in a complex traffic environment, simulation conditions that can dynamically update traffic information based on measured data were designed. Next, to increase the pure EV’s driving range, an energy efficient optimal control framework based on dynamic traffic information flow was proposed, which includes the traffic information layer, the target planning layer, and the prediction and control layer. In the traffic information layer, the vehicle receives and updates the traffic information data. The time-domain information and distance domain information are converted in the target planning layer and the optimal state-of-charge (SOC) reference trajectory is planned through the remote cloud computing system. The traffic information is predicted in the prediction and control layer, and an SOC scroll tracking control method is proposed to continuously control the power system to achieve the goal of optimal energy consumption and economic driving. Finally, under a variety of real road simulation conditions with dynamic traffic information, we verify that the economic performance of the proposed control framework is equivalent to that of the one based on dynamic programming algorithms and has the potential for online real-time control.

IoT Based Signal Violated Vehicle Detector

Abstract: The number of new vehicles on the road is increasing rapidly, which in turn causes highly congested roads and due to the long awaiting red signals, few vehicle drivers ignore traffic rules by violating traffic signals. This leads to a high number of road accidents and hence it is essential to detect the signal violated vehicles automatically. Traffic violation detection systems using IOT technology can able to send violated vehicle information to the concern traffic police station automatically by which the vehicle can be penalized immediately. The proposed system can be implemented using vehicle ID card installed in the vehicle itself such that if the vehicle moves further during presence of red signal, automatically, vehicle information in the form of vehicle registration number, type of vehicle (weather it is two-wheeler, car, truck, auto, etc.), owner name, vehicle colour, etc, can be forwarded to the concern authorities through concern mobile phones. To prove the concept practically, all vehicles must be equipped with these low-cost wireless ID cards such that the vehicle data can be transmitted continuously. The demo module contains a mini automatic traffic signal post along with simulated road. The system is designed such that when red signal is energized and during this period, if any vehicle crosses the zebra lines, the system receives the vehicle data and transmits the same through Wi-Fi module. If anybody violates the traffic signal, immediately alarm will be energized to alert the nearest traffic police. The main processor must be installed near the traffic signals, which regrets to acquire vehicle information during the presence of yellow and green signals. The demo module contains one toy car which will be equipped with its wireless ID card. Major building blocks: Simulation of single lane road constructed with traffic signal post & zebra crossing, main processor designed with Arduino MCU, wireless ID card designed with 89C2051 controller chip, IR signal decoder (TSOP1738), Wi – Fi module, Alarm, IR LED, 5v Power supply unit, Toy car, etc.

Influence of Lane-Changing Behavior on Traffic Flow Velocity in Mixed Traffic Environment

In mixed traffic with autonomous vehicles, the relationship between speed and lane-changing behavior is an important basis for mixed traffic control. In this study, we use empirical, simulation, and data-driven methods to study the relationship between speed and lane change rates in mixed traffic under different autonomous vehicle penetration rates. We use the empirical data to establish the corresponding road simulation models. Based on the simulation model, the traffic flow simulation experiments under the conditions of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% penetration rate of autonomous vehicles were carried out. The analysis of the simulation results found that: (1) the penetration of autonomous vehicles into the road has a positive impact on the lanes far away from the entrance and exit, while the impact on the lanes closer to the entrance and exit is not obvious. (2) Lane-changing behavior has effectively decreased with the penetration of autonomous vehicles, but it is not obvious when the penetration rate exceeds 10%, and there is no significant drop in the lane connecting the entrance and exit. (3) There is a linear relationship between speed and lane-changing rate. Under different penetration rates, the data-driven analysis is used to perform multiple linear regressions, and the regression formula fits are all above 0.7. Based on the above findings, the linear formula of the fitting is proposed, and the value interval of the parameters in different states is given as well. Due to the small changes in the parameter values under different permeability conditions, the model has a certain degree of stability. The speed-lane change rate model proposed in this study can better describe the relationship between the speed of the ring-shaped urban expressway and the lane-changing behavior in the mixed traffic environment with the larger traffic flow.

Effects of road slope on emission characteristics for a heavy-duty diesel vehicle based on engine-in-the-loop methodology

A dump truck with a maximum designed total mass of 24500 kg was selected to measure the emission characteristics of pollutants and carbon dioxide (CO2) under fully-loaded and unloaded conditions at the same simulated road with different road slope, same driver and vehicle model by using the engine-inthe- loop methodology. The results show that driving at gradient road will result in an increase in power and total emissions. The brake specific emissions of gaseous pollutant and CO2 are lower at gradient road, while the brake emission of particle number are higher at gradient road. Road slope affects exhaust temperature so as to affect nitrogen oxide (NOx) emissions. Under unloaded conditions, long-slope conditions are more likely to cause an increase in NOx emissions.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ УПРАВЛЕНИЯ ТРАНСПОРТНЫМИ ПОТОКАМИ НА НАГРУЗКИ ОСНОВНЫХ НЕСУЩИХ ЭЛЕМЕНТОВ И ПРОПУСКНУЮ СПОСОБНОСТЬ МОСТОВ

The article shows the influence of such methods of traffic flow management as limiting the speed of vehicles on the loads of the main load-bearing elements and the capacity of bridge structures on the example of the Oktyabrsky Bridge in Lipetsk. To determine the density of traffic flow and the load on the bridge structure, to collect information about the parameters of traffic flows, road traf-fic simulation is used. The vertical moving load on the bridge is calculated.

Overview of Spindle-Coupled Road Simulation Test Method for Vehicle Structure Durability

The durability of vehicle structure is one of the important performances to evaluate the quality of automobiles, and it has been paid more and more attention by automobile manufacturers and consumers. In the whole vehicle development process, automotive structural durability testing is essential. With the advantages of high test accuracy and short test cycle, road simulation test has become an effective test method in the vehicle development stage. Among them, the spindle-coupled road simulation test can most comprehensively reproduce the excitation of the road to the vehicle. The relevant test technology is synchronized with the rapid development of automotive products and keeps pace with the times, becoming one of the most deeply cultivated test technologies in the industry.

Optimization of Cab Suspension Using Tractor-Ride Vibration Simulation Model

HighlightsThis study created a simulation model to predict the ride vibration of a tractor and to optimize its suspension.The parameters of the tractor were obtained from various tests to create a fully validated model.The acceleration measured in a tractor cabin was compared with the simulation model in the time and frequency domains.The ride vibration of a tractor was evaluated under various road conditions with a fully validated model. Abstract. A typical problem with tractors and other agricultural machinery is the excessive ride vibration, which results in an inconvenient working environment and poses a risk to the health of operators. In this study, a simulation model for predicting the ride vibration of a tractor and optimizing the cabin suspension was developed to address this limitation. First, the required parameters used computation tests to create the simulation model. Mode and frequency-response function analyses were then performed to validate the model for ride vibration, from which the natural frequency and mode shape were analyzed. Subsequently, the riding characteristics of an actual tractor on a stepped road surface were simulated using a four-post road simulator, and the acceleration measured in the cab was compared with that of the simulation model in the time and frequency domains. Finally, the parameters of the cabin suspension were optimized using the validated simulation model, and the correlation between the cabin suspension parameters and ride vibration was examined. Following optimization, the vibration value of the tractor cab was found to decrease as the damping coefficient of the cabin suspension decreased for all surface conditions selected in the simulation. Thus, the developed tractor simulation model can be used as a ride vibration simulation when developing the control logic of a tractor’s cabin suspension, as well as a plant model of hardware-in-the-loop simulation to verify the control logic. Keywords: Hydro-pneumatic suspension, Optimization, Ride vibration, Simulation model, Tractor cab, Validation.

Effect of accelerator pedal hunting suppression mechanism on operability of off-road vehicles

Accelerator pedal is one of the important man-machine interfaces that affect vehicle drivability. Multi-purpose off-road utility vehicles are often used on rough roads. The excitation force from the road surface tends to affect the operability of the accelerator pedal. Many of the previous studies on pedal operation of passenger cars have investigated the effects of driving posture on pedal operability from an ergonomic point of view. But there are few studies have focused on accelerator pedal operability under rough terrain conditions. Therefore, we evaluated the operability of the accelerator pedal while driving on a rough road simulator and evaluated the operability of the vehicle running on rough terrain. The hunting suppression device generates resistance force that suppresses the hunting of the accelerator pedal in a vibrating condition and improves the vehicle speed controllability without increasing the operating muscle load.

Interior Acoustic Control System Using Boundary Vibration with Giant Magnetostrictive Actuator: Fundamental Consideration on the Control Algorithm

Ultra-compact electric vehicles (EVs) have been becoming increasingly popular recently. These vehicles have advanced characteristics such as compactness, light body, and low environmental impact. However, it is serious problem with interior noise which are from outside such as road noise and wind noise. Therefore, we have been studying an active noise control (ANC) system for ultra-compact EV by using the giant magnetostrictive actuator. In this paper, we propose a control system using an adaptive filter by least mean square (LMS) algorithm which is updating a filter coefficient continuously and brings the reduce noise. Furthermore, we studied fundamental considerations on simulation and noise reduction experiments for the development new ANC system using the giant magnetostrictive actuator. We performed noise reduction simulation using LMS algorithm and conducted low frequency noise simulated road noise reduction experiment by wall surface vibration using the giant magnetostrictive actuator. From the result of the simulation, the sound power became to close 0 Pa in the noise control system limitlessly by giving an appropriate step size parameter. Furthermore, in the noise reduction experiment, the sound pressure level of 200 Hz was reduced to 5.8 dB by controlling the noise. Comparing the results with the simulation, it was possible to reduce the noise level at the position of the driver's ears.

Can motorcyclist behavior in traffic conflicts be modeled? A deep reinforcement learning approach for motorcycle-pedestrian interactions

Traffic simulation models have been utilized recently in safety evaluations by calculating traffic conflict indicators from simulated road user trajectories. However, existing simulation models (1) do not accurately capture road users’ behaviour and evasive actions, and (2) do not consider road users’ intelligence and rationality. This study proposes a safety-oriented microsimulation framework for modeling conflict interactions between motorcyclists and pedestrians in mixed traffic conditions. Motorcyclists are modeled as utility-based rational and intelligent decision-makers using a Markov Decision Process (MDP). Continuous Inverse Reinforcement Learning (IRL) is proposed to recover the motorcyclists’ reward function using their actual trajectories. The recovered motorcyclists’ reward function provides inferences into their behavior in conflict interactions. The motorcyclists’ optimal policies (sequences of decisions) are estimated using the Actor-Critic Deep Reinforcement Learning. The results show that the model simulated motorcyclist trajectories and the evasive actions with high accuracy. Moreover, the predicted PETs correlated well with corresponding field-measured conflicts.

Simulation Analysis and Experiment Research on Hydro-Pneumatic ISD Suspension

To address the problems of mechanical two-stage inerter-spring-damper (ISD) suspension such as excessive suspension elements, complex structure, and problematic engineering implementation, a hydro-pneumatic two-stage ISD suspension, which integrates hydro-pneumatic spring and inerter, is proposed. The full vehicle model of hydro-pneumatic ISD suspension is established based on the AMESim. Simulation analysis is performed to demonstrate the effectiveness and performances of the proposed suspension. The hydro-pneumatic ISD suspension prototype is developed and tested on four-poster tire-coupled road simulator. The results suggest that, compared with single-chamber hydro-pneumatic suspension, the hydro-pneumatic ISD one can significantly reduce the vibrations of the vehicle body and wheels, but at the expense of an excessive increase of suspension working space (SWS). In contrast, although proposed suspension is also a type of dual-chamber hydro-pneumatic one, it can not only reduce these vibrations but also downsize the SWS, which means it is the best choice for a more comfortable and safer ride.

Extended Study of Full-Scale Wind Tunnel Test and Simulation Analysis Based on DrivAer Model

There is a great demand for car model series that can meet the needs of today’s research about vehicle aerodynamics due to the limitations of models used in the past. This paper focuses on the introduction of the extension of DrivAer model and discussions about the model’s experimental and simulation results. On the basis of DrivAer model, the upgrade and innovation of pickup styling back and concept of perception testing are added. Specifically, the SUV back and the Pickup back are redesigned in combination with Chinese aerodynamic design trend. The experiments were performed in a full-scale aero-acoustic wind tunnel with ground simulation system, consisting of boundary layer control system and five-belt system. Base on the wind tunnel experimental results, it can be found that the ground simulation has obviously influence on the drag coefficient, but has no influence on the distribution of surface pressure in upper body. The close state of the grilles, the absence of mirrors, and the fully enclosed of rims can significantly reduce the drag coefficient. Digital wind tunnel (DWT) simulation and open road (OR) simulation have been completed and verified with experimental results. It can be concluded that DWT simulation with the same geometry as the real wind tunnel performs better than the OR simulation. The maximum difference between the experimental results and the DWT simulation results does not exceed 2% and DWT simulation also performs well in the surface pressure simulation.

The Sustainable Development in Papua Based on Customary Territories and Human Development Paradigm

The National Development Planning Agency of Indonesia has adopted the concept of development based on customary territories in Papua in the 2015-2019 National Midterm Development Plan (RPJMN). This RPJMN aimed to accommodate the mandate of the Special Autonomy Law Number 21 of 2001 regarding Special Autonomy for Papua Province. However, the RPJMN used a top-down development approach that accommodates more national and international interests than local and customary territories' interests. The main objective of this paper is to propose a new concept of sustainable development that uses a bottom-up development approach to reconcile both interests above. The concept is supplemented with the road map and simulation to explore the progress of sustainable development. The modeling and simulation of sustainable development progress consist of the human development index (HDI), human development indicators, and electricity demand using the system dynamics model. In 2050, the lowest HDI is 63.87 in Mappi Regency. Life expectancy is 68.53 years; the schooling expecting years is 12.19 years; the schooling mean years is 6.60 years, and the expenditure per capita is Rp7,599,010, - In 2050, the highest HDI is 94.83 in Sorong Municipality. Life expectancy is 80.73 years; the schooling expecting years is 18.00 years; the schooling mean years is 15.00 years, and the expenditure per capita is Rp19,869,057 – In 2050, the electricity demand in Mappi Regency is 46,032 MWh. Meanwhile, the electricity demand in Sorong Municipality is 1,137,746 MWh.

A Method to Optimise Semi-Trailers with the Use of FEM Analysis and Durability Tests with a Road Simulator

This paper presents a method developed by Wielton company – a manufacturer of trailers and semi-trailers – for the optimization of semi-trailer’s construction, supported by FEM analysis and the modern road simulator – a test stand included as part of the method for optimising semi-trailers. The aim of the research was to optimize the process of developing a technical measure in terms of shortening the time of implementing new products while guaranteeing high durability and functionality of the products. As a result of the optimization of the construction with the use of FEM analysis and the road simulator, the semi-trailer as a new product for sale is delivered quickly and possible defects of construction are eliminated on early stage of new product development. The method assumes the following stages of the development process: determination of input data to the process, development of a 3D model, FEM numerical analysis (static and dynamic), development of an optimized 3D model based on numerical analyses, construction of the first prototype, prototype validation tests using the road simulator and other test stands. Important feature of the developed method to optimise construction is connected with specific data achieved from FEM analysis and used in tests with the road simulator. The effect of using presented method is the elimination of 98% errors in construction and technology. These errors concern not only the key parts of the semi-trailer, i.e. the body and the frame, but also less important components, i.e. fixing of tanks and boxes, ladder, spare wheel basket, extinguisher mounting. The method to optimise semi-trailers developed in Wielton have many advantages, such as: limiting the risk of launching breakthrough solutions on the market, faster increase in vehicle competitiveness, optimizing vehicle construction, reduction of production time and costs, and as a consequence - faster implementation of new products, reducing the number of complaints and service costs, increasing the value and prestige.