This work proposes to model a small series hydraulic hybrid vehicle (SHHV) for the power demand of a real driving cycle. The real driving cycle was measured with a low-cost Bluetooth Scanner connected to the On-Board Diagnostic (OBD) port of the vehicle and applied to a computational model. The hydraulic power to drive the modeled SHHV was supplied by a hydraulic pump and/or by an accumulator. Optimization tools were used to size the hydraulic components. Furthermore, the optimization tools were also used to calculate the values of the control variables for activating the pump, accumulator and the hydraulic motor, in order to have the minimum fuel consumption by the vehicle’s combustion engine. The model implemented had its fuel consumption reduced by 37% in relation to the passenger car utilized for the driving cycle data acquisition.

The main aim of this study is to analyze the fuel saving possibilities of optimized gear shifting strategies in a vehicle with a flex-fuel engine powered by both ethanol and gasoline when submitted to a real-world driving cycle. A computational model is implemented and, for each fuel option, an optimization problem is solved aiming at minimization of fuel consumption and traveling time. The standard and optimized gear shifting strategies obtained are experimentally evaluated where the new gear shifting shows a significant fuel consumption reduction without a significant increase in traveling time.

This paper aims to present the design of a new 3D-printed continuously variable transmission (CVT) developed for an electric vehicle prototype competing in Shell Eco-marathon electric battery category, a world-wide energy efficiency competition sponsored by Shell. The proposed system is composed of a polymeric conic geared friction wheel assembled in the motor axle and directly coupled to the rear tire of the vehicle. The conical shape allows to implement a continuous variation of the geared friction wheel diameter in contact with the tire. The motor with the geared friction wheel was mounted over a board with linear bearings, allowing the speed ratio to change by moving the board laterally. A computational simulation model of a prototype electric vehicle with the proposed 3D-printed CVT was created in Matlab/Simulink environment to obtain the traction force in the geared friction wheel and also to analyze the vehicle performance. The simulation results demonstrated possibilities of increasing vehicle speed range output and available torque in the rear traction wheel. Also, it is shown with the simulated model that the designed CVT consumes 10.46% less energy than a fixed transmission ratio, demonstrating the CVT concept’s potential for battery consumption reduction. Lastly, a 3D-printing slicing software with an optimization algorithm plug-in was used to determine the best printing parameters for the conic geared friction wheel based on the tangential force, maximum displacement and safety factor. When compared to the original part with a 100% infill density, the optimized solution reduced the component mass by about 12% while maintaining safe mechanical resistance and stiffness.