Browse Topic: Traction
ABSTRACT As a continuation of previous collaborative efforts between several US Army organizations and industry leaders which led to the procurement of a National Stock Number (NSN) for a near commercial-off-the-shelf winter tire/wheel assembly for the High Mobility Multipurpose Wheeled Vehicle (HMMWV), this study investigates a low-cost, postproduction modification known as ‘siping’ which may incrementally improve standard tires deployed on the Joint Light Tactical Vehicle (JLTV) in cold regions. Data from engineering tests will quantify performance differences as well as driver feedback from the 11th Airborne Division Soldiers in Alaska show moderate improvement from cutting razor-thin grooves known as ‘sipes’ on conventional winter tire sets. However, Army winter performance specifications developed in 2021 from HMMWV testing quantify greater available improvement to traction available, necessitating further development for winter traction in the JLTV family of tire sets as well as
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
ABSTRACT To advance development of the off-road autonomous vehicle technology, software simulations are often used as virtual testbeds for vehicle operation. However, this approach requires realistic simulations of natural conditions, which is quite challenging. Specifically, adverse driving conditions, such as snow and ice, are notoriously difficult to simulate realistically. The snow simulations are important for two reasons. One is mechanical properties of snow, which are important for vehicle-snow interactions and estimation of route drivability. The second one is simulation of sensor responses from a snow surface, which plays a major role in terrain classification and depends on snow texture. The presented work describes an overview of several approaches for realistic simulation of snow surface texture. The results indicate that the overall best approach is the one based on the Wiener–Khinchin theorem, while an alternative approach based on the Cholesky decomposition is the second
ABSTRACT This paper discusses the semi-active suspension system developed by A.M. General to provide mobility and maneuverability for tactical, wheeled vehicles
Symbolic code execution is a powerful cybersecurity testing approach that facilitates the systematic exploration of all paths within a program to uncover previously unknown cybersecurity vulnerabilities. This is achieved through a Satisfiability Modulo Theory (SMT) solver, which operates on symbolic values for program inputs instead of using their concrete counterparts. However, in complex code bases, this approach faces significant limitations, such as program path explosions or unavailable dependencies, which can result in conditions that the SMT solver cannot reason about. Consequently, SMT solvers are often considered as too costly to implement for automotive testing use cases and are rarely employed within this domain. In contrast, fuzz testing has recently gained traction in the automotive industry as an invaluable testing technique for identifying previously unknown vulnerabilities. Its initial setup is straightforward and typically yields useful findings. However, achieving
General Motors (GM) is working towards a future world of zero crashes, zero emissions and zero congestion. It’s “Ultium” platform has revolutionized electric vehicle drive units to provide versatile yet thrilling driving experience to the customers. Three variants of traction power inverter modules (TPIMs) including a dual channel inverter configuration are designed in collaboration with LG Magna e-Powertrain (LGM). These TPIMs are integrated with other power electronics components inside Integrated power electronics (IPE) to eliminate redundant high voltage connections and increase power density. The developed power module from LGM has used state-of-the art sintering technology and double-sided cooled structure to achieve industry leading performance and reliability. All the components are engineered with high level of integration skills to utilize across TPIM variants. Each component in the design is rigorously analyzed and tested from component to system levels to ensure high
In the quest for sustainable materials for automotive interior trim, jute fiber is gaining traction due to its characteristics, which align with other renowned natural fibers. This study aimed to assess the efficacy of sodium bicarbonate as a treatment for jute fibers in comparison to conventional alkaline treatments. Both treated and untreated fibers were examined. Results showed that alkali-processed fibers demonstrated enhanced crystallization, thermal resistance, and surface quality relative to untreated ones. Specifically, alkali-treated jute fibers exhibited a degradation onset at 261.23°C, while those treated with sodium bicarbonate began degrading at 246.32°C. Untreated fibers had a degradation onset at 239.25°C. Although both treatments improved the thermal stability of the fiber, sodium bicarbonate processing, while beneficial, was slightly less effective than the traditional alkaline method. Overall, the research underscores the potential of sodium bicarbonate as an
If a mid-20th century engineer could time travel and see Magna's electric off-road powertrains, they might ask “why is the rear differential so gigantic?” But that's no differential. It's a powerful electric motor fully integrated into each front and rear axle for full 4x4 traction. And Magna said the system will “very likely” be seen on a production vehicle within a few years. At its 2023 tech day presentation, held at a Michigan offroad park and Magna International HQ in Troy, Mich., SAE Media had the opportunity to drive prototype vehicles offroad and sample Magna's in-cabin safety features
Electrification of public transport in cities puts lots of stress onto the vehicle's traction batteries and the power grid during charging. The authors present a self-learning operating strategy to improve the battery life and reduce stress on the power grid by lengthening charging operations as long as possible and avoiding extreme states of charge. During regular service operation, the operating strategy observes the vehicle state and energy flows inside of the vehicle and between vehicle and charging infrastructure. Based on these observations, the operating strategy plans a guidance state of charge trajectory for the trip and dispatches recommendations for charging and discharging the traction battery to the vehicle's ECU. Additionally, the operating strategy ensures reliable service trips by checking if the current state of charge matches the estimated energy consumption for a fixed range laying ahead. The operating strategy can detect and mitigate a situation in which the vehicle
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