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Technical Paper

Proposal for Improving the Performance of Longitudinal Acceleration of a Land Vehicle

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.
Technical Paper

Estimation of Vehicle Tire-Road Contact Forces: A Comparison between Artificial Neural Network and Observed Theory Approaches

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.
Technical Paper

Performance and Emission Analysis of the Otto Cycle Engine Converted to Bi-Fuel Gasoline and Natural Gas (VNG)

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.
Technical Paper

Stratified Torch Ignition Engine: Performance Analysis

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.