Search Results

Research interests in autonomous driving have increased significantly in recent years. Several methods are being suggested for performance optimization of autonomous vehicles. However, weather conditions such as rain, snow, and fog may hinder the performance of autonomous algorithms. It is therefore of great importance to study how the performance/efficiency of the underlying scene understanding algorithms vary with such adverse scenarios. Semantic segmentation is one of the most widely used scene-understanding techniques applied to autonomous driving. In this work, we study the performance degradation of several semantic segmentation algorithms caused by rain for off-road driving scenes. Given the limited availability of datasets for real-world off-road driving scenarios that include rain, we utilize two types of synthetic datasets.

There is significant potential for connected and autonomous vehicles to impact vehicle efficiency, fuel economy, and emissions, especially for hybrid-electric vehicles. These improvements could have large-scale impact on oil consumption and air-quality if deployed in large Mobility-as-a-Service or ride-sharing fleets. As part of the US Department of Energy's current Advanced Vehicle Technology Competition (AVCT), EcoCAR: The Mobility Challenge, Mississippi State University’s EcoCAR Team is redesigning and doing the development work necessary to convert a conventional gasoline spark-ignited 2019 Chevy Blazer into a hybrid-electric vehicle with SAE Level 2 autonomy. The target consumer segments for this effort are the Mobility-as-a-Service fleet owners, operators and riders. To accomplish this conversion, the MSU team is implementing a P4 mild hybridization strategy that is expected to result in a 30% increase in fuel economy over the stock Blazer.

The current research conducted a cross-validation between an infrared motion capture system and an electromechanical motion capture device. No differences were found between the motion capture methods in shoulder and elbow angles. However, differences were found between the motion capture methods on distances of hand movements and actor location in space. Results of the current study indicate electromechanical motion capture devices are too inaccurate to use for validating digital human models unless the ultimate application of the model does not require millimeter accuracy or an absolute location in space. If one is primarily interested in joint angles, and distances are secondary, an electromechanical device is acceptable.

The Mississippi State University Formula SAE race car upright was optimized using radial basis function metamodels and an internal state variable (ISV) plasticity damage material model. The weight reduction of the upright was part of a goal to reduce the weight of the vehicle by 25 percent. Using an optimization routine provided an upright design that is lighter that helps to improve vehicle fuel economy, acceleration, and handling. Finite element (FE) models of the upright were produced using quadratic tetrahedral elements. Using tetrahedral elements provided a quick way to produce the multiple FE models of the upright required for the multi-objective optimization. A design of experiments was used to determine how many simulations were required for the optimization. The loads for the simulations included braking, acceleration, and corning loads seen by the car under track conditions.

Along the last thirty years one of the challenges is to develop an engine working with ethanol with the same performance and characteristics of gasoline engines functioning at low temperatures. In Brazil the production expansion of flex fuel engines is the main motivation for technology development and research to improve the engine cold start and functioning, when using ethanol. The use of gasoline as an auxiliary in the cold start system is now the main characteristic of this system. In this work the performance of a new cold start system is analyzed. Tests were performed in a vehicle and the results show the potential of the new technology.

For many years durability tests engineers have worked in the sense of improving the tests that, at first, were performed using public roads with high time consumption and low reproducibility. Proving grounds were specially designed to reproduce the most important efforts to the body and chassis systems, but time problem was still there. Time and cost reduction allied to the needs of quality, reliability and reproducibility improvement led the engineers to develop methods and equipments to reproduce the durability tests in the lab. In this way the road simulators appear as a powerful tool able to perform durability tests with high reliability, self-controlled and with very low time compared to the road tests. At this scenery bench tests were also created to components and systems mainly used to anticipate problems before a whole vehicle test.

Driven by the necessity to reduce costs and improve products quality the automotive industry replaced the design method known as "trial and error" by those grounded on mathematical and physical theory. In this context, a longitudinal performance test was made by BAJA SAE UFMG team, in order to acquire vehicular performance data that will be used to validate computer models. The methodology consists of sensors and data acquisition system research, validation, fixation and installation in the vehicle, test and process of acquired data. From these steps, correlated data were acquired from magnitudes such as angular velocity in transmission shafts, global longitudinal acceleration and velocity, travel of break and throttle pedals and pressure inside of master cylinder. These results developed the knowledge about vehicular dynamic allowing the improvement of futures prototypes.

This work presents a full analysis of a bi-fuel engine converted to natural gas and aims to survey the main performance losses and the advantages in specific consumption and toxic emissions. With this purpose, dynamometric tests and curves survey of a Fiat Palio 1.6, 16V engine, according to Standard NBR ISO 1585. Tests were made using diverse mixers, trying to obtain the losses caused by this device when the engine is working with gasoline, after the conversion. Tests were performed for different ignition advances, with manual and electronic VNG flow control systems. Trials for many differents low gear engine regulation, looking for consumption reduction and lower emission rates. The gas pressure reducer was tested with and without heating, showing differents results, mainly for emission rates. Other than comparing different components and different engine operation conditions, an analysis of two different natural gas conversion kits were performed, both extensile used in Brazil.

Global climate change and an increasing energy demand are driving the scientific community to further advance internal combustion engine technology. Invented by Sr. Henry Ricardo in 1918 the torch ignition system was able to significantly decrease engine’s fuel consumption and emission levels. Since the late 70s, soon after the Compound Vortex Controlled Combustion (CVCC) created by Honda, the torch ignition system R&D almost ceased due to the issues encountered by very complex and costly mechanic control systems that time. This work presents a stratified torch ignition prototype endowed with a sophisticated electronic control systems and components such as electro-injectors from direct injection systems placed on the pre-combustion chamber. The torch ignition prototype was tested and its performance are presented and compared with the baseline engine, which was used as a workhorse for the prototype engine construction.

The present study introduces a proposal to improve the longitudinal performance of a land vehicle through the adoption of an unusual traction control system. The system is capable of improving the transfer of engine power to the ground and reduces the complexity of the task being performed by the driver. High-performance vehicles are able to achieve high levels of longitudinal acceleration and, sometimes, the power excess leads to the spinoff of the drive wheels, which decrease the ability of the tires to generate force, and consequently the vehicle acceleration. The proposed system acts in addition with the motor control, through the derivation of the motor speed signal, and its control by comparison with a predefined value. The control can delay or even suppress the ignition of the engine. Thus, the rate at which the engine gains speed, and consequently, the rate at which the vehicle accelerates, is limited.

The aim of this work is to present the preliminary configuration design studies for an unmanned, lightweight (less than 15 kg), supersonic research aircraft. The studies comprise the aircraft typical mission, the aerodynamic and structural arrangement, preliminary performance, as well as mass distribution. The aircraft, an Unmanned Air Vehicle, or “UAV”, is named as Pohox (“arrow” in Maxakali indian language). It is intended to be the flying test bed for a multicycle engine capable to provide thrust in subsonic, transonic and supersonic regimes. In order to provide validation of the analysis tools, flight performance characteristics of a known, high speed aircraft - North American X-15 - have been also evaluated and compared with the available flight test data. The present analysis is an important step towards the aircraft detailed definition. And the features associated with the configuration obtained are good indications of the technical feasibility of this supersonic UAV.

This study examines the performance and subject acceptance level of a hand-operated brake actuator. Using a fixed-base vehicle simulator, data for driver reaction time, stopping time, distance, deceleration, customer acceptance and mental workload were collected. Data for three prototype hand-operated brake actuators and traditional foot-operated brake were compared. An additional test, designed to evaluate anthropometrics, sensitivity, and comfort was performed during training. A user preference survey to determine handbrake acceptance was given to subjects after completing the driving test in the simulator. In certain trials, participants were given the choice of handbrake or footbrake for an unexpected stop condition. When placed into an unexpected braking situation, subjects showed faster brake-application times for operating the hand-operated brake, indicating potential for reduced braking distance.

EcoCAR 2: Plugging In to the Future (EcoCAR) is North America's premier collegiate automotive engineering competition, challenging students with systems-level advanced powertrain design and integration. The three-year Advanced Vehicle Technology Competition (AVTC) series is organized by Argonne National Laboratory, headline sponsored by the U. S. Department of Energy (DOE) and General Motors (GM), and sponsored by more than 28 industry and government leaders. Fifteen university teams from across North America are challenged to reduce the environmental impact of a 2013 Chevrolet Malibu by redesigning the vehicle powertrain without compromising performance, safety, or consumer acceptability. During the three-year program, EcoCAR teams follow a real-world Vehicle Development Process (VDP) modeled after GM's own VDP. The VDP serves as a roadmap for the engineering process of designing, building and refining advanced technology vehicles.

A simple rugged acoustic stall sensor which has an output proportional to angle of attack near wing stall has been evaluated on a Cessna 319 aircraft. A sensor position has been found on the wing where the sensor output is only slightly affected by engine power level, yaw angle, flap position and wing roughness. The NASA LRC General Aviation Simulator has been used to evaluate the acoustic sensor output as a control signal for active stall deterrent systems. It has been found that a simple control algorithm is sufficient for stall deterrence.

The latest edition of the US Department of Energy's (DOE) Advanced Vehicle Technology Competition (AVTC) series is the EcoCAR Mobility Challenge (EMC). In the third year of the EMC, the Mississippi State University (MSU) team developed and tested a perception system and a longitudinal controller to achieve SAE level 2 autonomy. Our team leveraged the model-based design approach to iterate between developing software components and executing tests in multiple environments in the loop (XIL) to verify that design requirements are met. This workflow allowed us to detect and resolve issues early in the development process. The perception system is composed of a sensor fusion and tracking algorithm. It relies on detections from a front facing camera and radar to generate tracks for a leading vehicle. The tracks from the perception system are used by a model predictive controller (MPC) to maintain a safe distance to the leading vehicle.

The EcoCAR Mobility Challenge (EMC) is the latest edition of the Advanced Vehicle Technology Competition (AVTC) series sponsored by the US Department of Energy. This competition challenges 11 North American universities to redesign a stock 2019 Chevrolet Blazer into an energy-efficient, SAE level 2-autonomous mild hybrid electric vehicle (mHEV) for use in the Mobility as a Service (MaaS) market. The Mississippi State University (MSU) team designed a P4 electric powertrain with an 85kW (113.99 HP) permanent magnet synchronous machine (PMSM) powered by a custom 5.4 kWh lithium-ion energy storage system. To maximize energy efficiency, Model Based Design concepts were leveraged to optimize the overall gear ratio for the P4 system. To accommodate this optimized ratio in the stock vehicle, a custom offset gearbox was designed that links the PMSM to the rear drive module.

One of the principal goals of modern vehicle control systems is to ensure passenger safety during dangerous maneuvers. Their effectiveness relies on providing appropriate parameter inputs. Tire-road contact forces are among the most important because they provide helpful information that could be used to mitigate vehicle instabilities. Unfortunately, measuring these forces requires expensive instrumentation and is not suitable for commercial vehicles. Thus, accurately estimating them is a crucial task. In this work, two estimation approaches are compared, an observer method and a neural network learning technique. Both predict the lateral and longitudinal tire-road contact forces. The observer approach takes into account system nonlinearities and estimates the stochastic states by using an extended Kalman filter technique to perform data fusion based on the popular bicycle model.

A common interaction between a penetrator and a target has been the use of copper and nickel materials. However, a multiscale analysis has not been performed on such a system. Compared to steels, aluminum alloys, titanium alloys and other metallic materials, a description of the mechanical behavior of pure ductile metals such as Cu struck by a penetrator comprises nickel under the high strain rate at different multiscale still remains unknown. In this research, Modified Embedded Atom Method (MEAM) Potential is utilized to study this system and the molecular dynamics simulation is employed in order to provide structure property evolution information for plasticity and shearing mechanisms.

This paper presents the design of two cleaning systems following systems engineering design approach. An in situ cleaning system was designed for removing engine oil stains and metal swarf and shavings that adhere to rollers of conveying lines which convey cylinder head as well as other heavy engine components. The other system was to clear and collect metal debris accumulated in the grooves of an engine block internal assembly line. Prototypes were fabricated for the designed cleaning equipment for further testing and assessment. In the system engineering design process, preliminary, intermediate, and detailed design were conducted following an identification of the design problem, within that process a sequence of tasks such as synthesis, analysis, prototyping, and assessment were completed.

Currently the durability test of FIAT vehicles powertrain suspension system is performed in pattern roads that reproduces conditions which the vehicle is submitted by costumer during product life cycle. The test done in these roads is time consuming and expensive. Experimental Engineers, for quite some time, have endeavored in doing automotive components fatigue tests in the lab. These environments provide more controlled test conditions and enable a less time consuming test. This work analyzes, over one of the three powertrain system attachment points of a passenger vehicle, differences that are found between a test performed in pattern roads and a test performed in a 6DOF road simulator. As conclusion, presents alternatives to perform the test of these components in lab using a 6DOF road simulator.