Browse Topic: Transportation Systems

Items (4,390)
This study proposes a multi-mode switching control strategy based on electromagnetic damper suspension (EMDS) to address the different performance requirements of suspension systems on variable road surfaces. The working modes of EMDS are divided into semi-active damping mode and energy harvest mode, and the proposed mode switching threshold is the weighted root mean square value of acceleration. For the semi-active damping mode, a controller based on LQR(Linear Quadratic Regulator) was designed, and a variable resistance circuit was also designed to meet the requirements of the semi-active mode, which optimized the damping effect relative to passive suspension. For the energy harvest mode, an energy harvest circuit was designed to recover vibration energy. In order to reduce the deterioration of suspension performance caused by frequent mode switching in the mode switching strategy, as frequent system switching can lead to system disorder, deterioration of damping effect, and
Zeng, ShengZhang, BangjiTan, BohuanQin, AnLai, JiewenWang, Shichen
ABSTRACT Ground vehicle mobility in soft soil is crucial to many military missions. Thus, it has been tested and quantified in a metric called Vehicle Cone Index (VCI) since World War II. VCI provides an index of the minimum soil strength necessary for vehicle mobility. The standard operating procedure for VCI field testing and data analysis is detailed herein. Also, a new method for quantifying VCI uncertainty has been proposed, which uses confidence bounds on mean measurements of soil strength. A sample analysis of actual field data is provided
Stevens, Maria T.Towne, Brent W.Osorio, Javier E.Mason, George L.
This study aims to explore the multifaceted influencing factors of market acceptance and consumer behavior of low-altitude flight services through online surveys and advanced neuroscientific methods (such as functional magnetic resonance imaging fMRI, electroencephalography EEG, functional near-infrared spectroscopy fNIRS) combined with artificial intelligence and video advertisement quantitative analysis. We conducted an in-depth study of the current trends in low-altitude flight vehicle development and customer acceptance of low-altitude services, focusing particularly on the survey methods used for market acceptance. To overcome the influence of strong opinion leaders in volunteer group experiments, we designed specialized surveys targeting broader online and social media groups. Utilizing specialized knowledge in aviation psychology, we designed a distinctive questionnaire and, within just 7 days of its launch, gathered a significant number of valid responses. The data was then
Ma, XinDing, ShuitingLi, Yan
The life and safety of a battery are closely linked to temperature. Designing an effective thermal management system relies on a thorough understanding and analysis of the thermal properties and mechanisms of the battery. Over time, as batteries are used, their thermal characteristics change due to variations in internal SEI thickness, the deterioration of the active material structure, gas production, and electrolyte consumption, all of which are associated with the aging process. In this paper, experiments on both NCM and LFP batteries were made to measure the heat generation characteristics by adiabatic calorimeter. The results showed that the impact of calendar aging on battery heat generation exhibited completely different patterns for the lithium-ion batteries of the two material systems mentioned above. This paper provides guidance for the optimization of heat generation characteristics of battery and the calibration of heat source in the design of battery thermal management
Li, HaibinZhao, HongweiLiu, DinghongHu, Qiaosheng
Integrating 3D point cloud and image fusion into flying car detection systems is essential for enhancing both safety and operational efficiency. Accurate environmental mapping and obstacle detection enable flying cars to optimize flight paths, mitigate collision risks, and perform effectively in diverse and challenging conditions. The AutoAlignV2 paradigm recently introduced a learnable schema that unifies these data formats for 3D object detection. However, the computational expense of the dynamic attention alignment mechanism poses a significant challenge. To address this, we propose a Lightweight Cross-modal Feature Dynamic Aggregation Module, which utilizes a model-driven feature alignment strategy. This module dynamically realigns heterogeneous features and selectively emphasizes salient aspects within both point cloud and image datasets, enhancing the differentiation between objects and the background and improving detection accuracy. Additionally, we introduce the Lightweight
Feng, XiaoyuZhang, RenhangChu, ZhengWei, LinaBian, ChenDuan, Linshuai
An electric vertical take-off and landing aircraft (eVTOL) is a variety of vertical take-off aircraft driven by electric power. This work proposed a new boundary condition control method to investigate the take-off and landing process of eVTOL, which is under the conditions of a typical atmospheric boundary layer. The spatial flow field information, especially the height-dependent atmospheric crosswind velocity profile, will be projected on the temporal axis and superimposed with the existing time-dependent unsteady conditions. Taking a 4-axis eVTOL as an example, computational fluid dynamics (CFD) simulations based on unsteady Reynolds-Averaged Navier-Stokes (uRANS) and rigid body motion (RBM) are carried out with proposed unsteady boundary conditions. The loads and surrounding flow field of the aircraft are obtained, while the vortical structures are further identified and discussed. Notably, the impact of atmospheric boundary layer on the aerodynamic force of eVTOL during vertical
Wei, HuanxiaJia, ChundongShi, YongweiJia, QingXia, ChaoMo, RengYang, ZhigangLi, YanlongHu, Qiangqiang
ABSTRACT Route planning plays an integral role in mission planning for ground vehicle operations in urban areas. Determining the optimum path through an urban area is a well understood problem for traditional ground vehicles; however, in the case of autonomous unmanned ground vehicles (UGVs), additional factors must be considered. For a UGV, perception, rather than mobility, will be the limiting factor in determining operational areas. Current ground vehicle route planning techniques do not take perception concerns into account, and these techniques are not suited for route planning for UGVs. For this study, perception was incorporated into the route planning process by including expected sensor accuracy for GPS, LIDAR, and inertial sensors into the path planning algorithm. The path planner also accounts for additional factors related to UGV performance capabilities that affect autonomous navigation
Durst, Phillip J.Goodin, ChristopherSong, PeilinDu, Thien K.
ABSTRACT The diverse range of military vehicles and operational conditions share a number of powertrain objectives including high fuel efficiency and fuel adaptability to lessen the logistical impact of conflict; low heat rejection to minimize the cooling system losses, vulnerability and powertrain package space; tractive power delivery to provide superior mobility for the vehicle; and light weight to allow for more armor to be used and/or payload to be carried. This paper first provides an overview of the operational powertrain requirements of military vehicles. A review the processes used to integrate powertrain components into an optimized system specifically developed for modern combat vehicle applications is then provided, including an example of how the process was employed to develop an advanced powertrain for a tactical vehicle demonstrator based on military optimized off-the-shelf components. The paper concludes with a summary of some further military specific engine and
Hunter, Gary
The highway diverging area is a crucial zone for highway traffic management. This study proposes an evaluation method for traffic flow operations in the diverging area within an Intelligent and Connected Environment (ICE), where the application of Connected and Automated Vehicles (CAVs) provides essential technical support. The diverging area is first divided into three road sections, and a discrete state transition model is constructed based on the discrete dynamic traffic flow model of these sections to represent traffic flow operations in the diverging area under ICE conditions. Next, an evaluation method for the self-organization degree of traffic flow is developed using the Extended Entropy Chaos Degree (EECD) and the discrete state transition model. Utilizing this evaluation method and the Deep Q-Network (DQN) algorithm, a short-term vehicle behavior optimization method is proposed, which, when applied continuously, leads to a vehicle trajectory optimization method for the
Fang, ZhaodongQian, PinzhengSu, KaichunQian, YuLeng, XiqiaoZhang, Jian
ABSTRACT Currently, many small Army ground robots have mobility configurations containing tracks with sets of dual or quad flipper configurations. Many of these robots include the iRobot PackBot, Talon, and Dragon Runner. While the preceding robotic designs have allowed these robots to navigate over obstacles and across low traction environments, an increasing need for agile robotic platforms in complex environments involving subterranean and urban structure missions will be critical in the future. Therefore, a new mobility system for dismounted ground robots is being researched to aid in the exploration, mapping, and identification by targets of interest for dense urban environments. This paper discusses one possibility for a new small CRS-I sized ground robot mobility system that is inspired by the rocker-bogie designs of the Mars rover systems. Citation: Timothy Pietrzyk, Ty Valascho “Robotic Rocker-Bogie Mechanism Prototype”, In Proceedings of the Ground Vehicle Systems Engineering
Pietrzyk, TimothyValascho, Ty
ABSTRACT Ground vehicle soft soil mobility has been studied for decades. Standard measurements, such as cone penetrometer, determine soil strength which helps analyze vehicle mobility. These methods are only available where data can be collected. As off-road vehicles transition to autonomous and semi-autonomous, real time in-situ analysis of soil strength is becoming a necessity. Databases such as GeoWATCH provide coarse (30-90m geospatial resolution) mobility parameter estimates. Hydrologic events can cause rapid changes in mobility which may not be effectively captured by these databases. In order to make real time predictions for autonomous vehicles, it is necessary to develop a method to determine mobility parameters without operator intervention. A system using rut depth measurements (collected via optical and ultrasonic sensors) and vehicle parameters was developed from established methods to estimate soil strength. The results were compared to corresponding physical measurements
Fischell, Jason N.Hansen, Bradley S.Jackson, J. RebekahEylander, John B.
ABSTRACT As unmanned ground vehicle technology matures and autonomous platforms become more common, such platforms will invariably be in close proximity to one another both in formation and independently. With an increasingly crowded field, the risk of collisions between these platforms grows, and with it the need for path deconfliction. This paper presents two complementary technological developments to this end: a pipeline for affirmatively identifying and classifying dynamic objects, e.g., vehicles or pedestrians; and a pipeline for preventing collisions with such objects. The efficacy of these techniques is demonstrated in simulation, and validation on robotic platforms will be undertaken in the near future. Citation: Matthew Grogan, “Dynamic Object Collision Avoidance for Autonomous Multi-Vehicle Systems in the Robotic Technology Kernel”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019
Grogan, Matthew
ABSTRACT Tracks and wheels are some of the top constituents of ground vehicle mobility and sustainment cost. Even small improvements in performance parameters and support strategies can go a long way. Analyzing equipment sustainment models can help identify these opportunities in conjunction with maintaining a situational awareness of R&D activities. Specifically, understanding component failure analysis, characterizing production road wheel material properties, conducting component testing, and benchmarking diverse manufacturing capabilities provides a roadmap to establishing and identifying “Best in Class” road wheel materials. Establishing and executing an R&D compounding plan to deliver 5X-10X durability improvement is hypothesized. Leveraging the Defense Mobility Enterprise (DME) and its authority under the 10 USC 2370 Section 845 Ground Vehicle Systems Other Transaction Agreement will allow the government to rapidly determine the technical feasibility of realizing such colossal
Patria, Garett S.Rescoe, StuBradford, WilliamMynderse, James A.
This paper investigates the drag reduction matching of modular flying cars based on a nested configuration. To address the high aerodynamic drag issue of traditional modular flying car configurations, a nested design scheme is proposed. In this scheme, the cabin is extracted from a low-drag car and combined with the flying module using a nested approach, achieving aerodynamic matching between the cabin, driving module, and flying module. First, the conceptual design of the new modular flying car and the parameters of each module, including the driving module, cabin module, and flying module, are introduced. Then, computational fluid dynamics (CFD) methods are utilized to numerically simulate the aerodynamic characteristics of the new flying car, and the results are compared with the existing typical modular flying car, AIRBUS. The research results show that the nested modular flying car exhibits superior aerodynamic performance in both driving and flying modes. Compared to the typical
Li, YanlongYe, ShengfeiZhou, Hua
In the realm of low-altitude flight power systems, such as electric vertical take-off and landing (eVTOL), ensuring the safety and optimal performance of batteries is of utmost importance. Lithium (Li) plating, a phenomenon that affects battery performance and safety, has garnered significant attention in recent years. This study investigates the intricate relationship between Li plating and the growth profile of cell thickness in Li-ion batteries. Previous research often overlooked this critical aspect, but our investigation reveals compelling insights. Notably, even during early stage of capacity fade (~ 5%), Li plating persists, leading to a remarkable final cell thickness growth exceeding 20% at an alarming 80% capacity fade. These findings suggest the potential of utilizing cell thickness growth as a novel criterion for qualifying and selecting cells, in addition to the conventional measure of capacity degradation. Monitoring the growth profile of cell thickness can enhance the
Zhang, JianZheng, Yiting
ABSTRACT Knowing the soil’s strength properties is a vital component to accurately develop Go/No-Go mobility maps for the Next Generation NATO Reference Mobility Model (NG-NRMM). The Unified Soil Classification System (USCS) and soil strength of the top 0-6” and 6-12” of the soil are essential terrain inputs for the model. Current methods for the NG-NRMM require in-situ measurement of soil strength using a bevameter, cone penetrometer, or other mechanical contact device. This study examines the use of hyperspectral and thermal imagery to provide ways of remotely characterizing soil type and strength. Hyperspectral imaging provides unique spectrums for each soil where a Soil Classification Index (SCI) was developed to predict the gradation of the soil types. This gradation provides a means of identifying the soil type via the major divisions within the USCS classification system. Thermal imagery is utilized to collect the Apparent Thermal Inertia (ATI) for each pit, which is then
Ewing, JordanOommen, ThomasJayakumar, ParamsothyAlger, Russell
ABSTRACT The normal reaction force in the tire-soil patch is a continuously changing wheel parameter. When a vehicle moves over uneven ground, motion in the vehicle’s sprung and unsprung masses produce dynamic shifts in the magnitude of the load transmitted to the ground. With the damping force controlled for better ride quality, tight constraining of the sprung mass motion may lead to significant dynamic changes of the normal load. At excessive loads, the wheel can dig into the soil. Considerably reduced loads can negatively impact vehicle steerability and diminish traction performance. The purpose of this paper is to develop a method that allows for establishing boundaries of the dynamic normal reaction in the tire-soil patch on uneven terrain. The boundary constraints are considered for both maximum and minimum values to establish conditions for mobility and steerability. Using differential equations describing the motion two masses of a single-wheel module representing a vehicle
Paldan, JesseVantsevich, VladimirGorsich, DavidGoryca, JillSingh, AmandeepMoradi, Lee
ABSTRACT Current modeling and simulation capabilities permit tackling complex multi-physics problems, such as those encountered in ground vehicle mobility studies, using high-fidelity physics-based models for all involved subsystems, including the vehicle, tires, and deformable terrain. However, these come at significant computational burden; research and development on new software architecture and parallelization techniques is crucial in enabling such predictive simulation capabilities to be useful in design of new vehicles or in operational settings. In this paper, we describe the architecture, philosophy, and implementation of a distributed message-passing-based granular terrain simulation capability and its incorporation into an explicit force–displacement co-simulation framework to enable effective simulation of multi-physics mobility problems. We demonstrate that the proposed infrastructure has good parallel scaling characteristics and can thus effectively leverage available
Serban, RaduOlsen, NicholasNegrut, Dan
ABSTRACT This work presents the development of an algorithm to incorporate measurements from multiple antennas to improve the relative position solution between convoying vehicles provided by Global Positioning System (GPS) measurements. The technique presented, incorporates measurements from multiple antennas with a known fixed-baseline between a base antenna and auxiliary antenna on a base vehicle, and a rover antenna on a rover vehicle. The additional information provided by the fixed-baseline distance is used to provide an additional measurement with low uncertainty for improved integer ambiguity resolution between the base and auxiliary receiver, which in turn, provides additional measurements for determining the integer ambiguity difference between the base and rover receivers for the computation of a high-precision relative position vector (HPRPV
Tabb, Thomas T.Bevly, DavidMartin, ScottRatowski, Jeff
ABSTRACT This work investigates the effects of obstacle uncertainty on the speed, distance, and feasibility of a planned traversal path. Simulation results for artificial and real-world environments are used to numerically quantify how geometric uncertainty within a map affects path traversal cost. A significant outcome of this research is the discovery of a relationship between increasing uncertainty and path cost. As obstacle uncertainty increases, previously planned routes can become infeasible as they effectively become blocked off due to uncertainty in the obstacle geometry. This paper illustrates a method that can serve to increase the speed, simplicity, and reliability of path planning, while allowing uncertainty to be included in the mobility analysis. Citation: S. Tau, S. Brennan, K. Reichard, J. Pentzer, D. Gorsich, “The Effects of Obstacle Dimensional Uncertainty on Path Planning in Cluttered Environments”, In Proceedings of the Ground Vehicle Systems Engineering and
Tau, SethBrennan, SeanReichard, KarlPentzer, JesseGorsich, David
ABSTRACT Leader-follower autonomous vehicle systems have a vast range of applications which can increase efficiency, reliability, and safety by only requiring one manned-vehicle to lead a fleet of unmanned followers. The proper estimation and duplication of a manned-vehicle’s path is a critical component of the ongoing development of convoying systems. Auburn University’s GAVLAB has developed a UWB-ranging based leader-follower GNC system which does not require an external GPS reference or communication between the vehicles in the convoy. Experimental results have shown path-duplication accuracy between 1-5 meters for following distances of 10 to 50 meters. Citation: K. Thompson, B. Jones, S. Martin, and D. Bevly, “GPS-Independent Autonomous Vehicle Convoying with UWB Ranging and Vehicle Models,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022
Thompson, KyleJones, BenMartin, ScottBevly, David
ABSTRACT The NATO Reference Mobility Model (NRMM) is a simulation tool aimed at predicting the capability of a vehicle to move over specified terrain conditions. NRMM was developed and validated by the U.S. Army Tank Automotive Research, Development, and Engineering Center (TARDEC) and Engineer Research and Development Center (ERDC) in the 1960s and ‘70s, and has been revised and updated through the years, resulting in the most recent version, NRMM v2.8.2b. It was originally used to facilitate comparison between vehicle design candidates by assessing the mobility of existing vehicles under specific terrain scenarios, but has subsequently and most recently found expanded use in support of complex decision analyses associated with vehicle acquisition and operational planning support. This paper summarizes recent efforts initiated under a NATO Exploratory Team (ET) and its follow-on Research Technical Group (RTG) to upgrade this key modeling and simulation tool and the planned path
McCullough, MichaelJayakumar, ParamsothyDasch, JeanGorsich, David
ABSTRACT A high-fidelity physics-based approach for predicting vehicle mobility over large terrain maps is presented. The novelties of this paper are: (i) modeling approach based on seamless integration of multibody dynamics and the discrete element method (DEM) into one solver, and (ii) an HPC-based design-of-Experiments (DOE) approach to predict the off-road soft soil mobility of ground vehicles on large-scale terrain maps. A high-fidelity multibody dynamics model of a typical 4x4 military vehicle is used which includes models of the various vehicle systems such as chassis, wheels/tires, suspension, steering, and power train. A penalty technique is used to impose joint and contact constraints. A general cohesive soil material DEM model is used which includes the effects of soil cohesion, elasticity, plasticity/compressibility, damping, friction, and viscosity. To manage problem size, a novel moving soil patch technique is used in which DEM particles which are far behind the vehicle
Wasfy, Tamer M.Jayakumar, ParamsothyMechergui, DaveSanikommu, Srinivas
Yaw control for aircraft using the rudder faces challenges in resisting fast time-varying uncertainty due to the relatively slower response of the rudder. In hybrid unmanned aerial vehicles equipped with both rudders and rotors, the introduction of powered yaw control offers novel solutions for addressing fast time-varying uncertainty by leveraging the quicker response of rotors compared to traditional rudders. This paper presents a hierarchical yaw control approach for hybrid unmanned aerial vehicles, comprising a nominal control for rudders to achieve the desired yaw tracking and a constrained powered yaw control for rotors to resist fast time-varying uncertainty. Given the constrained amplitude of powered yaw control, it is imperative that the designed auxiliary input guarantees adherence to its constraint. Firstly, a nonlinear control for nominal hybrid unmanned aerial vehicle system is formulated to deal with the nonlinearity model, rendering a modest nominal control for rudders
Dai, JiawenLiu, JiaojiaoYang, YiBai, JieZhang, Zheshuo
This paper explores the groundbreaking applications of plasma propulsion engines and advanced nanomaterials in low-altitude aircraft, addressing the challenges and recent technological advancements that make such applications feasible. Traditional space plasma thrusters operate effectively in near-vacuum conditions by taking advantage of the ease of plasma ignition at low pressures. However, these thrusters face significant difficulties when operated at near-atmospheric pressures found in low-altitude environments, where plasma ignition is challenging. This paper highlights recent breakthroughs in high-pressure plasma glow discharge technology and the integration of nanomaterials, which together enable the use of plasma propulsion engines in low-altitude aircraft. These innovations offer substantial advantages over conventional engines, including higher efficiency, reduced emissions, and the potential to fundamentally change the propulsion systems of low-altitude aircraft
Ma, XinDing, ShuitingPan, YilunLiu, JinshuoQiao, HuizheYang, Jincai
In the context of insufficient international management experience, this study combines the current situation of Chinese aviation and the characteristics of unmanned aircraft (UA) operation, adopts the specific operations risk assessment (SORA) method, and conducts in-depth research on the trial operation risks of UA in urban low-altitude logistics scenarios, conducting effective evaluations and project practices. This study starts from two dimensions of ground risk and air risk, determines the boundaries required for safe operation of UA, and improves the robustness level of UA operation through ground risk mitigation measures and air risk mitigation measures. At the same time, a series of compliance verification methods are provided to meet 24 operational safety objectives (OSO) (including design characteristics, operational limitations, performance standards, safety characteristics, communication requirements, emergency response plans, etc.), ensuring that UA operation does not pose
Li, LiLiu, WeiweiFu, Jinhua
ABSTRACT Due to shortcomings in vehicle mobility prediction in the NATO Reference Mobility Model (NRMM), recommendations and requirements for the Next-Generation NATO Reference Mobility Model (NG-NRMM) are under development. The limiting nature of empirically based terramechanics and the recent decades of significant improvements to 3D physics based Modeling and Simulation (M&S) capability call for a process to quantify physics based M&S in meeting the proposed goals of NG-NRMM. A verification and validation (V&V) process is demonstrated to quantify the vehicle mobility prediction capability of current state of the art physics based M&S tools. The evaluation is based upon an M&S maturity scale adopted and modified from corporate simulation governance to fit the specifics of vehicle mobility. The V&V process is demonstrated through a set of benchmarks, one for a tracked and another for a wheeled vehicle. The NG-NRMM benchmark efforts have demonstrated an analytical process for
Balling, OleMcCullough, MichaelHodges, HenryPulley, ReidJayakumar, Paramsothy
ABSTRACT Determining the required power for the tractive elements of off-road vehicles has always been a critical aspect of the design process for military vehicles. In recent years, military vehicles have been equipped with hybrid, diesel-electric drives to improve stealth capabilities. The electric motors that power the wheel or tracks require an accurate estimation of the power and duty cycle for a vehicle during certain operating conditions. To meet this demand, a GPS-based mobility power model was developed to predict the duty cycle and energy requirements of off-road vehicles. The dynamic vehicle parameters needed to estimate the forces developed during locomotion are determined from the GPS data, and these forces include the following: the gravitational, acceleration, motion resistance, aerodynamic drag, and drawbar forces. Initial application of the mobility power concept began when three U.S. military’s Stryker vehicles were equipped with GPS receivers while conducting a
Ayers, PaulBozdech, George
ABSTRACT This paper describes aspects of the Safe Operations of Unmanned Systems for Reconnaissance in Complex Environments (SOURCE) Army Technology Objective (ATO) that affect urban terrain autonomous mobility R&D programs. The SOURCE ATO provides essential large platform autonomous capabilities for executing unmanned reconnaissance missions, such as leader-follower, move-on-route, tele-operation, and remote situational awareness. The system includes multi-modal, high resolution, all-digital sensors which support nighttime and daytime operations. The SOURCE ATO development includes different classes of UGV vehicles as well as different classes of perception sensor technology. To date, the SOURCE ATO has successfully completed two out of three scheduled field experiments. The paper presents the latest SOURCE ATO results
DiBerardino, ChipMottern, Edwardvan Lierop, Tracy K.Mikulski, DariuszKott, N. Joseph
Internet of vehicles (IoV) system as a typical application scenario of smart city, trajectory planning is one of the key technologies of the system. However, there are some unstructured spaces such as road shoulders and slopes pose challenges for trajectory planning of connected-automated vehicle (CAV). Therefore, this paper addresses the problem of CAV trajectory planning affected by unstructured space. Firstly, based on cyber-physical system (CPS), the cyber-physical trajectory planning system (CPTPS) framework was built. A high-precision digital twin CAV is established based on the physical properties and geometric constraints of CAV, and the digital model is mapped to cyber space of the CPTPS. In order to further reduce the energy consumption of the CAV during driving and the time spent from the start to the end, a model was established. Further, based on the sand cat swarm hybrid particle swarm optimization algorithm (SCSHPSO), global path planning for connected-automated vehicles
Ma, ShiziMa, ZhitaoShi, YingYang, ZhongkaiLai, DaoyinQi, Zhiguo
ABSTRACT Commercial OEMs are fast realizing the long awaited dream of self-driving trucks and cars. The technology continues to improve with major implications for the Army. In the near tear, the impact may be most profound for military installations. Many believe, however, that the major limiting factor to wide-spread automated vehicle usage will not be technology but the human element. What happens when humans through no choice of their own are compelled to interact with self-driving vehicles? We propose a mixed-methods research study that examines the complex transportation system from both a technical and social perspective. This study will inform environmental controls (rules of the road and infrastructure modifications) and increase understanding of the social dynamics involved with vehicle acceptance. Findings may pave the way for a reduction in the over $400M the Army spends annually on non-tactical vehicles and the technical improvements, grounded in dual-use use cases will be
Straub, Edward
As a novel passive control method, the acoustic black hole (ABH) structure demonstrates achieve energy aggregation efficiently and has the characteristics of lightweight and wide-band noise reduction. This study applies ABH theory to aircraft ducts by incorporating an additional ABH structure into the inner wall design. The spiral structure is specifically engineered to increase the characteristic length of the black hole and lower the cutoff frequency. To validate the effectiveness of this ABH structural design, finite element analysis was conducted to investigate structural frequency response, acoustic energy concentration characteristics, as well as damping and energy dissipation effects. Simulation results indicate significant energy accumulation on the inner wall with ABH structure in frequencies above 800Hz. Additionally, through acoustic-structure coupling analysis, far-field acoustic radiation characteristics were determined for this structural design followed by a
Guo, YaningLv, PengLiu, PengfeiNing, Donghong
The advent of the low-altitude economy represents a novel economic paradigm that has emerged in recent years in response to technological advancement and an expanding social demand. The low-altitude economy is currently undergoing a period of rapid development, which underscores the importance of ensuring the safety of airfield operations. To enhance operational efficiency, unmanned aerial vehicles (UAVs) can be utilized for the inspection of the surrounding area, runway inspection, environmental monitoring, and other tasks. This paper employs TurMass technology, the TurMass gateway is miniaturised as the communication module of FT24, and the TK8620 development board replaces the LoRa RF module in the ELRS receiver to achieve the communication transmission between the remote control and the receiver. Additionally, a TurMass chip is integrated into the UAV to transmit beacons, while an airfield management aerial vehicle is employed to receive nearby UAV data, thereby preventing
Zhang, XiaoyangChen, Hongming
Aiming at the position and attitude separation control problem of the “X” configuration tiltable quadrotor, an appointed-time prescribed performance anti-disturbance control method is proposed. Firstly, the tiltable quadrotor’s model description and dynamic model are presented, in which the virtual control inputs are defined to solve the non-affine control allocation problem trickly. Then, appointed-time prescribed performance control laws are designed for position and attitude angle control subsystems to guarantee tracking errors’ transient and steady-state performance. Furthermore, fixed-time extended state observers are designed to compensate for the lumped disturbance in velocity and angular rate control subsystems. And the quadratic programming method is used to solve the control allocation problem considering energy optimization. Finally, the simulation results demonstrated the effectiveness of the proposed method
Wu, TiancaiBai, JieWang, FangShi, ZhiguoXingchen, Yue
ABSTRACT Consumer demand and regulatory pressure have forced automakers to develop features designed to increase passenger car safety regardless of road surface or weather condition. In response, the intelligent tire, proposed in the APOLLO report, is introduced and the parameters useful for traction control system development are identified. Traction control system models are introduced and discussed. A simple vehicle model based on the quarter-car is presented, incorporating a traction control system and tire friction model. This model utilizes the LuGre friction model to relate tractive force to slip ratio and road surface friction level. A sliding-mode control strategy is chosen to model traction control behavior. Three case studies are conducted on two simulated road surfaces to show the interaction between estimated friction level in the sliding-mode control strategy and the tire friction model. To simulate the intelligent tire, where the road surface friction level is directly
Binns, RobertTaheri, SaiedFerris, John B.
ABSTRACT This paper presents two techniques for autonomous convoy operations, one based on the Ranger localization system and the other a path planning technique within the Robotic Technology Kernel called Vaquerito. The first solution, Ranger, is a high-precision localization system developed by Southwest Research Institute® (SwRI®) that uses an inexpensive downward-facing camera and a simple lighting and electronics package. It is easily integrated onto vehicle platforms of almost any size, making it ideal for heterogeneous convoys. The second solution, Vaquerito, is a human-centered path planning technique that takes a hand-drawn map of a route and matches it to the perceived environment in real time to follow a route known to the operator, but not to the vehicle. Citation: N. Alton, M. Bries, J. Hernandez, “Autonomous Convoy Operations in the Robotic Technology Kernel (RTK)”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI
Alton, NicholasBries, MatthewHernandez, Joseph
ABSTRACT We describe a simulation environment that enables the design and testing of control policies for off-road mobility of autonomous agents. The environment is demonstrated in conjunction with the design and assessment of a reinforcement learning policy that uses sensor fusion and inter-agent communication to enable the movement of mixed convoys of conventional and autonomous vehicles. Policies learned on rigid terrain are shown to transfer to hard (silt-like) and soft (snow-like) deformable terrains. The enabling simulation environment, which is Chrono-centric, is used as follows: the training occurs in the GymChrono learning environment using PyChrono, the Python interface to Chrono. The GymChrono-generated policy is subsequently deployed for testing in SynChrono, a scalable, cluster-deployable multi-agent testing infrastructure that uses MPI. The Chrono::Sensor module simulates sensing channels used in the learning and inference processes. The software stack described is open
Negrut, D.Serban, R.Elmquist, A.Taves, J.Young, A.Tasora, A.Benatti, S.
ABSTRACT Military personnel involved in convoy operations are often required to complete multiple tasks within tightly constrained timeframes, based on limited or time-sensitive information. Current simulations are often lacking in fidelity with regard to team interaction and automated agent behavior; particularly problematic areas include responses to obstacles, threats, and other changes in conditions. More flexible simulations are needed to support decision making and train military personnel to adapt to the dynamic environments in which convoys regularly operate. A hierarchical task analysis approach is currently being used to identify and describe the many tasks required for effective convoy operations. The task decomposition resulting from the task analysis provides greater opportunity for determining decision points and potential errors. The results of the task analysis will provide guidance for the development of more targeted simulations for training and model evaluation from
Garrison, Teena M.Thomas, Mark D.Carruth, Daniel W.
ABSTRACT This paper describes research into the applicability of anomaly detection algorithms using machine learning and time-magnitude thresholding to determine when an autonomous vehicle sensor network has been subjected to a cyber-attack or sensor error. While the research community has been active in autonomous vehicle vulnerability exploitation, there are often no well-established solutions to address these threats. In order to better address the lag, it is necessary to develop generalizable solutions which can be applied broadly across a variety of vehicle sensors. The current measured results achieved for time-magnitude thresholding during this research shows a promising aptitude for anomaly detection on direct sensor data in autonomous vehicle platforms. The results of this research can lead to a solution that fully addresses concerns of cyber-security and information assurance in autonomous vehicles. Citation: R. McBee, J. Wolford, A. Garza, “Detection and Mitigation of
McBee, RyanWolford, JonathanGarza, Abe
ABSTRACT Evolving requirements for combat vehicles to provide increased mission capability and/or crew safety necessitate the addition of components and add-on armor to currently-fielded vehicles. These new requirements result in increased weight and increased electrical needs, which result in reduced mobility. The APD is built from the ground up to optimize a powertrain solution using cutting-edge technology specifically designed for harsh military environments, for use in both vehicle retrofits and new vehicle designs. The APD combines an efficient 1000 hp engine, transmission, integrated starter generator, thermal management system, and lithium-ion batteries to maximize powerpack power density. The APD was designed for a 45-60 ton combat vehicle, but designing for scalability, reconfigurability, and using modern techniques and technology has allowed the APD to greatly improve the capability and flexibility of the powerpack and the technology can be applied to heavier or lighter
Claus, MikeLaRoy, DavidNickel, DavidPanagos, ConstantinePesys, TomasSkillman, NewtonSrodawa, JohnTadros, Maged
ABSTRACT Occupant safety is a top priority of military vehicle designers. Recent trends have shifted safety emphasis from the threats of ballistics and missiles toward those of underbody explosives. For example, the MRAP vehicle is increasingly replacing the HMMWV, but it is much heavier and consumes twice as much fuel as its predecessor. Recent reports have shown that fuel consumption directly impacts personnel safety; a significant percentage of fuel convoys that supply current field operations experience casualties en route. While heavier vehicles tend to fare better for safety in blast situations, they contribute to casualties elsewhere by requiring more fuel convoys. This study develops an optimization framework that uses physics-based simulations of vehicle blast events and empirical fuel consumption data to calculate and minimize combined total expected injuries from blast events and fuel convoys. Results are presented by means of two parametric studies, and the utility of the
Hoffenson, StevenKokkolaras, MichaelPapalambros, PanosArepally, Sudhakar
ABSTRACT To improve robustness of autonomous vehicles, deployments have evolved from a single intelligent system to a combination of several within a platoon. Platooning vehicles move together as a unit, communicating with each other to navigate the changing environment safely. While the technology is robust, there is a large dependence on data collection and communication. Issues with sensors or communication systems can cause significant problems for the system. There are several uncertainties that impact a system’s fidelity. Small errors in data accuracy can lead to system failure under certain circumstances. We define stale data as a perturbation within a system that causes it to repetitively rely on old data from external data sources (e.g. other cars in the platoon). This paper conducts a fault injection campaign to analyze the impact of stale data in a platooning model, where stale data occurs in the car’s communication and/or perception system. The fault injection campaign
Louis, August St.Calhoun, Jon C.
ABSTRACT A framework for generation of reliability-based stochastic off-road mobility maps is developed to support the Next Generation NATO Reference Mobility Model (NG-NRMM) using full stochastic knowledge of terrain properties and modern complex terramechanics modelling and simulation capabilities. The framework is for carrying out uncertainty quantification and reliability assessment for Speed Made Good and GO/NO-GO decisions for the ground vehicle based on the input variability models of the terrain elevation and soil property parameters. To generate the distribution of the slope at given point, realizations of the elevation raster are generated using the normal distribution. For the soil property parameters, such as cohesion, friction and bulk density, the min and max values obtained from geotechnical databases for each of the soil types are used to generate the normal distribution with a 99% confidence value range. In the framework, the ranges of terramechanics input parameters
Choi, K.K.Gaul, NicholasJayakumar, ParamsothyWasfy, Tamer M.Funk, Matthew
ABSTRACT Many significant advances have been made in autonomous vehicle technology over the recent decades. This includes platooning of heavy trucks. As such, many institutions have created their own version of the basic platooning platform. This includes the California PATH program [1], Japan’s “Energy ITS” project [2], and Auburn University’sCACC Platform [3]. One thing these platforms have in common is a strong dependence on GPS based localization solutions. Issues arise when the platoon navigates into challenging environments, including rural areas with foliage which might block receptions, or more populated areas which might present urban canyon effects. Recent research focus has shifted to handling these situations through the use of alternative sensors, including cameras. The perception method proposed in this paper utilizes the You Only Look Once (YOLO) real-time object detection algorithm in order to bound the lead vehicle using both RGB and IR cameras. Range and bearing are
Flegel, TylerChen, HowardBevly, David
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