Gear shifting optimization applied to a flex-fuel vehicle under real driving conditions

Research on gear decision method of commercial vehicle based on predictive road information

“…Neural network 4,15 Heavy-duty vehicle -Not considering changes in real-time information Rain flow counting 5 Heavy-duty vehicle -Not considering road conditions Genetic algorithm 6,7,10 Electric vehicle Driving style Different fuels Not considering road conditions MPC 8,9,18 Electric vehicle Vehicle speed Not considering road conditions Adaptive control 11 Electric vehicle Driving style Not considering changes in real-time information Greedy algorithm 12 Passenger car --K-means clustering algorithm 13 Electric bus -Not considering changes in real-time information Shifting map 14 Passenger car Driving intention Cannot be optimized online DRNN 15 Passenger car -Not considering changes in real-time information Dynamic programming 16 Heavy-duty vehicle -Slope shift strategy only considered Equivalent motor efficiency 17 Electric bus -For special drivetrain…”

“…The optimized gear can reduce fuel consumption and not significantly increase travel time. 10 Lin et al proposed an adaptive shift strategy based on the driver's behavior. The dynamic correction factor was introduced for the fixed shift strategy to modify the dynamic correction coefficient of different driving styles and adjust the ratio between economic performance and power performance in the shifting process.…”

Modelagem e simulação de um sistema start/stop para redução de consumo de combustível e emissões de gases poluentes

“…Figure 1 illustrates the resistive forces the vehicle is subject to during motion. Figure 1 -Free-body diagram of vehicle adapted from [21] The required torque [Nm] (2)…”

“…Thus, the clutch transmissible torque is determined by Equation 7, as proposed by Kulkami, Shim and Zhang [40], according to its friction coefficient , external and internal disks' radii [m] and number of faces . For the simulation model, the gear shifting process was introduced based on the procedure defined in [20], [21]. The time of 0.3 s was assumed for the ICE decoupling from the gearbox, followed by the posterior gear shifting during 0.2 s and, finally, the gradual clutch recoupling, which occurs for 0.5 s. The clutch spring force [N] varies according to the pedal position, as presented in Figure 3.…”

“…Such alternatives include vehicle redesign with lighter-weight materials [12], devices for aerodynamic drag reduction [13], tire design to decrease rolling resistance [14], [15], drivetrain design improvement [16], [17] and engine downsizing [18]. Moreover, studies have shown that an optimum gear shifting control results in significant reduction of gas emissions and vehicle fuel consumption [19]- [21]. Hybridization is another appealing alternative to achieve better fuel economy and emission indexes [22], [23].…”