Browse Topic: Mobility

Items (1,376)
ABSTRACT GS Engineering has developed technology to advance the sensory perception of autonomous systems. The Automatic Terrain Detection System (ATDS) is a technology that provides real time terrain detection. Vehicles deployed with ATDS have been able to yield improved mobility, automation of systems, and reduced fuel consumption. ATDS has been integrated into the MK23 MTVR, M1151 HMMWV for the ONR Predictive Adaptive Mobility (PAM) program, and into the Autonomous Ground Re-supply (AGR) by-wire kit for the Oshkosh Defense Palletized Load System (PLS). The ATDS is built upon proven sensors running integrated processing to replace or enhance existing vehicle systems. Citation: D. Subert, A. Diepen, K. Hubert, “Automatic Terrain Detection”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019
Subert, DavidDiepen, AndrewHubert, Kevin
ABSTRACT The Product Director Light Tactical Vehicles (PdD LTV) is responsible for the Army’s High Mobility Multipurpose Wheeled Vehicle (HMMWV) family of vehicles. Due to the large number of variants found throughout the Army plus the continued need for their service into the foreseeable future, the Army has conducted extensive depot recapitalization programs and continues to explore modernization options to sustain enduring requirements. Because competing performance requirements exist and budget constraints demand careful design choices, PdD LTV commissioned the development of a Whole System Trades Analysis Tool (WSTAT) specified for the HMMWV family of vehicles to help gain an analytic understanding of the key performance, cost, risk, and growth tradeoffs inherent within their potential designs. The WSTAT provides a holistic framework for modeling and understanding these tradeoffs. In this paper, the overarching WSTAT methodology is presented along with the specific implementation
Ballantine, MarissaDessanti, AlexPierson, AdamHo, YangDinunzio, MichaelCardinale, TeraCosta, LauraHopkinson, DanielPykor, Nathan
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 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 This paper discusses the semi-active suspension system developed by A.M. General to provide mobility and maneuverability for tactical, wheeled vehicles
Tackett, WendellLovell, JeffreyBrown, Chris
ABSTRACT The following paper describes the new SAPA automatic transmissions for the future military vehicles. The very high mobility requirements, the reclaim of weight, power & space and the actual relevance of the fuel consumption require a rethinking and a new vision of the automatic transmission concept and design. This is what SAPA has been working on for the last 12 years obtaining excellent technical and commercial results, a concept aimed at reducing the power losses of the conventional powershifting transmission eliminating the torque converter, reducing the spin losses -due to hydraulic pumps and friction discs-, and improving vehicle mobility on variable terrain situations as off-road
Telleria, Iñigo Garcia-Eizaga
ABSTRACT As part of an Internal Research and Design effort to take existing disparate technologies and integrate them into a single autonomous vehicle to advance the state-of-the-art in unmanned ground vehicle autonomy, SwRI has developed a data representation and routing algorithm to deal with the complexities of interconnecting urban roadways and the static and dynamic hazards in such an environment. The program was designed to utilize data from a Route Network Definition File (RNDF), which contains a priori roadway network data. Using its known location and a given destination, the vehicle determines the shortest route to completion. If, during traversal of that route, the vehicle detects an obstacle in its path using its on-board sensors, it will dynamically re-route its path whether that requires changing lanes on a multiple lane road or turning around completely and finding a different route if the path is completely blocked
Mentzer, ChristopherMcWilliams, GeorgeKozak, Kristopher
ABSTRACT U.S. Army Combat Capabilities Development Command (CCDC) Ground Vehicle Systems Center (GVSC) has been managing and developing a variety of autonomous systems throughout its existence. Two of the most important from the past decade include the Autonomous Mobility Appliqué System (AMAS) developed by Lockheed Martin Corporation (LMC) and the Robotic Technology Kernel (RTK) developed by GVSC in collaboration with DCS Corp and Southwest Research Institute (SwRI). Rather than continuing to develop and maintain two separate autonomous software systems, GVSC has decided to integrate any capabilities that were unique to AMAS into RTK and devote efforts to developing RTK going forward. The goal of integrating AMAS into RTK is to leverage the best features of each system. The process of this integration involves multiple steps. This paper describes the historical and current efforts involved in the integration of AMAS into RTK. Citation: D. Pirozzo, J.P. Hecker, A. Dickinson, T
Pirozzo, DavidHecker, Joshua P.Dickinson, AlanSchulteis, TimRatowski, JeffTheisen, Bernard
ABSTRACT Off-road autonomous navigation poses a challenging problem, as the surrounding terrain is usually unknown, the support surface the vehicle must traverse cannot be considered flat, and environmental features (such as vegetation and water) make it difficult to estimate the support surface elevation. This paper will focus on Robotic Research’s suite of off-road autonomous planning and obstacle avoidance tools. Specifically, this paper will provide an overview of our terrain detection system, which utilizes advanced LADAR processing techniques to provide an estimate of the surface. Additionally, it will describe the kino-dynamic off-road planner which can, in real-time, calculate the optimal route, taking into account the support surface, obstacles sensed in the environment, and more. Finally, the paper will explore how these technologies have been applied to a wide variety of different robotic applications
Lacaze, AlbertoMottern, EdwardBrilhart, Bryan
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 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 Seasonality plays a key role in altering the terrain of many military operating environments. Since seasonality has such a large impact on the terrain, it needs to be properly accounted for in vehicle dynamics models. This work outlines a variety of static and dynamic seasonal terrain conditions and their impacts on vehicle mobility in an austere region of Europe. Overall the vehicles performed the best in the dry season condition. The thaw season condition had the most drastic impact on mobility with all but the heavy tracked vehicle being almost completely NOGO in the region. Overall, the heavy tracked vehicle had the best performance in all terrain conditions. These results highlight the importance of incorporating seasonal impacts on terrain into NRMM or any vehicle dynamics model. Future work will focus on collecting more data to improve the empirical relationships between vehicles and seasonal terrain conditions, thereby allowing for more accurate speed predictions
Hodgdon, Taylor S.Shoop, Sally A.Frankenstein, SusanBigl, Matthew F.Parker, Michael W.
ABSTRACT The Autonomous Warrior Transport On-base (AWTO) pilot project is an Applied Robotics for Installations and Base Operations (ARIBO) project that addresses the real-world needs of the Warrior Transition Battalion at Fort Bragg. Soldiers in this battalion, some of whom have mobility difficulties, often require transportation assistance from the barracks to the Womack Army Medical Center. TARDEC and Robotic Research are utilizing robotic technology to provide an unmanned transport system equipped with a reservation/reminder system for these soldiers and caretakers. As a result, we are combining operational value and experimentation, creating a practical-to-tactical strategy that leverages existing autonomy R&D programs to build on increasingly complex operational scenarios
Mottern, EdwardPutney, JosephStraub, EdwardBarghout, 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 The NATO Reference Mobility Model (NRMM) is an empirically based tool developed to facilitate comparisons between vehicle design candidates and to assess their mobility under specific mission profiles. It was originally established in the 1960s and 1970s, during a time when modern computational methods were in their infancy. Since its initial development, the NRMM has been revised and updated several times, but there has always been a deficiency – a thorough understanding of the vehicle capabilities for each mission profile. With the advent of modern simulation tools, coupled with the latest in data visualization and analytics, a new generation of mobility models may be built that cannot only assess a vehicle’s mobility, but also understand its extended range in various soil types, and more specific terrains or operational conditions. This presentation will discuss the capabilities of advanced simulation and visualization software and their ability to affect how mission
Pesheck, EricPalmer, TimBromwell, TonyJeganathan, Venkatesan
ABSTRACT To address the need for rapid capture of terrain profiles, and changes in terrain, researchers from Michigan Tech demonstrated a UAS collection system, during a live exercise, supported by the North Atlantic Treaty Organization’s (NATO) Science and Technology Organization (STO). The UAS collection system was deployed to provide high resolution topography (resolution less than 1 cm) with a terrain collection rate greater than 1 meter per second and results were processed within minutes. The resulting topography is of sufficient quality to demonstrate that the technique can be applied to update mobility models, as well as the detection of traverse by ground vehicles
Dobson, Richard J.Buller, William T.Bradley, Scott A.
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
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
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 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 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 The work presented in this contribution demonstrates the results of the verification and validation efforts of simulation versus test of the mobility of a light tactical vehicle, the Fuel Efficiency Demonstrator, FED-Alpha. The simulations are the contribution to the Cooperate Demonstration of Technology (CDT) of Next Generation NATO Reference Mobility Model as performed by the Aarhus University (AU) team using Jet Propulsion Laboratory’s (JPL) ROver Analysis, Modeling and Analysis Software ROAMS. The work demonstrates hard surface automotive tests as well as soft soil tire-terrain terramechanics tests such as drawbar pull on fine and coarse grained soils and a variable sand slope test on coarse grained soil. Furthermore, a traverse of mixed terrain types and the results of a developed off-road driver model are shown as a demonstrator of Next-Generation NATO Reference Mobility Model simulation capability. Citation: O. Balling, M. Rydahl-Haastrup, L. Bendtsen, F. Homaa, C. Lim
Balling, OleRydahl-Haastrup, MortenBendtsen, LouiseHomaa, FrederikLim, Christopher S.Gaut, AaronJain, Abhinandan
ABSTRACT An inverse dynamics approach is applied to assess the relationship and establish an adjustable balance between acceleration performance, slip energy efficiency, and mobility margins of a wheel of a vehicle with four wheels individually-driven by electric DC motors. The time history of the reference wheel torques are recovered which would enable the motion at the desired linear velocity. Target velocity profiles are applied which provide different rates of acceleration. The profiles are simulated in stochastic terrain conditions which represent continuously changing, uncertain terrain characteristics with various quality of rolling resistance and peak friction coefficient. A wheel mobility margin is determined to track how close a driving wheel is to immobilization. When moving in drastically changing stochastic terrain conditions, boundaries are adjusted to accommodate changes in the resistance to motion in order to guarantee the motion while not exceeding limits which would
Paldan, JesseVantsevich, VladimirGorsich, DavidJayakumar, ParamsothyMoradi, Lee
ABSTRACT Mobility is a crucial vehicle requirement for the Army, as it needs to ensure that soldiers to not become immobilized in conflict. The Army currently pays thousands of dollars annually in order to obtain licenses for commercial software to analyze vehicle mobility. The High Performance Computing Modernization Program (HPCMP) Computational Research and Engineering Acquisition Tools and Environments for Ground Vehicles (CREATE™-GV) Mercury attempts to provide the Army with a high-fidelity tool that can analyze mobility at the same level as commercial software, while being owned and developed by the government. By providing a government owned mobility software, Mercury eliminates licensing fees and allows development of the software to be focused on military applications and what the Army needs. Mercury can continuously evolve to meet the Army’s future goals and requirements. Mercury currently is capable of modeling many vehicle subsystems in order to provide very robust vehicle
Brendle, JacobWoten, JacobBoyle, SaraMange, JeremySkorupa, Thomas
ABSTRACT In 2014, a NATO Applied Vehicle Technology (AVT) Exploratory Team 148 (ET-148) was formed to explore the development of an improved Next-Generation NATO Reference Mobility Model (NG-NRMM)[1]. A development path forward was identified and initiated in a subsequent NATO research task group (AVT-248) to implement ET-148 recommendations. One key area for improvement was the vehicle-terrain interaction (Terramechanics) models defining important performance metrics for off-road performance in differing soils, and environmental conditions. The near term implementation focuses on existing “Simple” Terramechanics models as a practical improvement to the incumbent NRMM Cone Index (CI) empirically based method, without requiring the computational power of the large scale complex discrete element model (DEM) methods that are the targeted long term solution. Practical approaches and limitations to the implementation of these existing Simple Terramechanics models in 3D vehicle models are
McCullough, MichaelPreston-Thomas, JonShoop, SallyJayakumar, ParamsothyHodges, Henry
ABSTRACT This paper is concerned with the physics-based simulation of light tracked vehicles operating on rough deformable terrain. The focus is on small autonomous vehicles, which weigh less than 100 lb and move on deformable and rough terrain that is feature rich and no longer representable using a continuum approach. A scenario of interest is, for instance, the simulation of a reconnaissance mission for a high mobility lightweight robot where objects such as a boulder or a ditch that could otherwise be considered small for a truck or tank, become major obstacles that can impede the mobility of the light autonomous vehicle and negatively impact the success of its mission. Analyzing and gauging the mobility and performance of these light vehicles is accomplished through a modeling and simulation capability called Chrono::Engine. Chrono::Engine relies on parallel execution on Graphics Processing Unit (GPU) cards
Negrut, DanMazhar, HammadMelanz, DanielLamb, DavidJayakumar, ParamsothyLetherwood, MichaelJain, AbhinandanQuadrelli, Marco
Multi-sensor fusion (MSF) is believed to be a promising tool for vehicular localization in urban environments. Due to the differences in principles and performance of various onboard vehicle sensors, MSF inevitably suffers from heterogeneous sources and vulnerability to cyber-attacks. Therefore, an essential requirement of MSF is the capability of providing a consumer-grade solution that operates in real-time, is accurate, and immune to abnormal conditions with guaranteed performance and quality of service for location-based applications. In other words, an MSF algorithm depends heavily on data synchronization, cost, an accurate process model, a prior knowledge of covariance matrices, integrity assessments, and security against cyber-attacks. Multi-sensor Fusion-based Vehicle Localization addresses trending technologies in MSF-based vehicle localization and outlines some insights into the unsettled issues and their potential solutions. The discussions and outlook are presented as a
Guo, GeLiu, JiagengLiu, Guangheng
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