1,720,972 research outputs found
Influence of Working Conditions and Operating Parameters on the Energy Consumption of a Full-Electric Bus. Experimental Assessment
No full textInfluence of Chassis Torsional Stiffness of an Agricultural Vehicle on Rollover Stability
No full textAn experimental analysis of driver influence on battery electric bus energy consumption
No full textWith the increasing emphasis on environmental sustainability, the electrification of urban public bus fleets has gained significant attention. In this context, understanding the factors influencing the energy consumption of battery electric buses (BEBs) is crucial for optimizing their operation. This paper presents an analysis of the influence of driver behavior on BEB energy consumption based on experimental measurements. The study investigates the relationship between energy consumption, traffic conditions, and driver characteristics using data collected from an 18-day experimental campaign involving a 12 m full-electric battery bus operating on four different routes. Various parameters, including vehicle mass, driver behavior, route characteristics, and environmental conditions, are analyzed to assess their impact on BEB energy consumption. Results indicate a strong correlation between driver behavior, particularly acceleration patterns and throttle pedal utilization, and energy consumption of the electric traction motor. Overall, this study provides valuable insights into optimizing BEB operations for enhanced sustainability and performance in urban transportation systems
Optimal Cooperative Brake Distribution Strategy for IWM Vehicle Accounting for Electric and Friction Braking Torques
Get PDFElectric vehicles are spreading in automotive industry pushed by the need of reducing greenhouse gas. However, the use of multiple electric motors, i.e., one per wheel, allows to redefine the vehicle powertrain layout with great benefits on vehicle dynamics. Electric motors braking torque is in general not enough to produce high decelerations. Hydraulic friction brakes are still necessary for safety reasons and to avoid oversized motors. This paper presents a control strategy for distributed electric motors (EM), one per wheel, to maximize the regenerative braking. The controller handles cooperative braking among EMs and hydraulic brakes, which are still necessary to guarantee top braking performance of the car. The proposed algorithm considers the driver requested braking torque as well as the required yaw moment by stability control system. Motor efficiency map and wheel normal load are considered to optimally distribute the torques. With respect to conventional distribution strategies, the presented algorithm improves performance, maximizing the regenerative braking power
Analysing the Effect of Chassis Torsional Flexibility on the Rollover Threshold of a Multi-Purpose Agricultural Vehicle
Get PDFMulti-purpose agricultural tractors are vehicles that are usually involved in different operations, including road maintenance in small villages and cultivation of small agricultural plots, particularly in mountainous areas. These vehicles typically feature narrow tracks to enhance manoeuvrability, making rollover stability a critical consideration in operational settings. This characteristic arises from the interplay between the suspension and vehicle chassis. This paper introduces a numerical multi-body model designed to replicate the dynamics of a multi-purpose tractor with a torsional chassis. Model parameters were derived through experimental measurements conducted on an actual vehicle. Static measurements were performed to assess tire and suspension stiffness while tilting tests were performed to establish the static rollover limit of the vehicle. Dynamic tests conducted on a four-post test rig characterised the vehicle’s dynamics. The validated model was utilised to explore the vehicle’s stability by reproducing the static rollover tests and simulating the vehicle’s performance under working conditions on a banked road. The vehicle rollover stability was studied by performing a sensitivity analysis that considered both chassis torsional stiffness and suspension stiffness under different loading conditions. The results indicate a trade-off between frame and suspension stiffnesses that enhances overall vehicle stabilit
A Comprehensive Analysis of Energy Consumption in Battery-Electric Buses Using Experimental Data: Impact of Driver Behavior, Route Characteristics, and Environmental Conditions
Get PDFWith the increasing emphasis on environmental sustainability, the electrification of urban public bus fleets has gained significant attention. Understanding the factors influencing the energy consumption of battery-electric buses (BEBs) is crucial for enhancing their energy efficiency. Therefore, it is crucial to identify the subsystems that contribute most to energy consumption and understand how operational factors influence them. This paper presents a comprehensive analysis of BEB energy consumption based on experimental measurements performed with a 12 m fully electric battery bus. The main limitations of this study stem from the use of a single vehicle over a total period of 18 days, during which 187 routes were completed. Additionally, sandbags were used as ballast in place of actual passengers. Various parameters, including the number of passengers, drivers, route characteristics, environmental conditions, and traffic, were analyzed to assess their impact on BEB energy consumption. Data related to the energy consumed by various bus utilities were collected through the vehicle’s CAN network, with a sampling rate of 1 measurement per second. These data were analyzed both daily and per route, revealing the breakdown of energy consumption among different utilities and highlighting those responsible for the highest energy use. The results correlate the total distance traveled, service duration, average speed, driver’s driving style, route characteristics, internal and external temperatures, and air-conditioning system’s reference temperature with the energy consumption of the traction motors and climate control system. In addition, the correlation between the driver, vehicle acceleration, and throttle pedal use, and the energy consumed by the electric traction motor is presented
A Regenerative Braking Strategy for Independently Driven Electric Wheel Accounting for Contemporary Use of Electric and Hydraulic Brakes
No full textThe growth of electric mobility showed the possibility of reinventing the vehicle powertrain layout. The adoption of one motor per wheel allows to precisely control the driving and braking torque on each wheel. However, conventional friction brakes are necessary to guarantee top braking performance of the car since, in general, the braking toque by electric motor is not enough to perform maximum deceleration manoeuvres. A suitable blended braking distribution strategy must be designed to distribute the torques on the wheel by accounting for the vehicle state, the driver request, and the torque vectoring request by stability control algorithm. This paper presents and optimal control strategy that distributed the braking torques on the wheel accounting for electric and hydraulic brakes. The control algorithm considers than the regulations requirements, the wheel vertical load condition both in longitudinal and lateral dynamics conditions, and the request by driver and stability control
Design of a Test Rig for Tuning and Optimization of High Dynamics Servo-Mechanisms Employed in Manufacturing Automation
Get PDFThe Industry 4.0 framework is pushing the manufacturing systems towards a zero-defect production based on robot technologies. The increasing level of automation in the production lines is raising new challenges for designers that must face the latest requirements in terms of product quality and power consumption. Among the multitude of components of the industrial plants, Servo-Mechanisms (SMs) play a crucial role and govern important performance indices of both robots and automatic machines. During the execution of high dynamics tasks, the SMs performance is influenced by many factors, including motion law, acting load, temperature and degradation. The development of accurate models aiming at predicting and optimizing the SMs behavior may not be practicable without extensive experimental activities. Owing to these considerations, this work introduces a novel test rig for the accurate characterization of industrial SMs. The rig is designed by combining the advantages of the existing prototypes. It is equipped with high precision sensors and an active loading system that enable to test the SM in various working conditions. Also, the rig modularity facilitates the installation of newly commissioned components and the execution of static and dynamic experiments. The paper mainly focuses on the rig mechanical design and components selection criteria
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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