Henryk Wnęk

This article presents an analysis of the operation of the electric motor, generator, and internal combustion engine within the hybrid powertrain system of a Toyota Corolla. To compare data regarding energy utilization from these sources, a specially designed diagnostic scanner was employed in our laboratory, enabling the capture of data from the vehicle's Controller Area Network (CAN). The tests were conducted on a laboratory chassis dynamometer, taking into account the NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonised Light Duty Vehicle Test Procedure) protocols. Additionally, experiments were performed under real urban traffic conditions. The analysis of the collected data provided detailed insights into the operation of the aforementioned components, which are integral to the powertrain during characteristic driving scenarios. For selected test fragments, an analysis of energy consumption and recovery by the electric motor and generator is presented.

Nowadays, the automotive market offers cars equipped with various types of drive systems, including a classic system in which the internal combustion engine burns fuel to power the vehicle, a hybrid system in which the internal combustion engine is supported by an electric machine (MHEV), and an electrical system in which energy to power the vehicle is drawn from the battery (BEV). Hybrid and electric vehicles have the ability to recover energy during deceleration and braking. Choosing a car with the right drive system is not easy for the average vehicle user. The article presents a comparison of vehicles with various drive systems. For this purpose, a diagnostic scanner was created that allows reading data from the car’s CAN network. The comparison of the obtained data allows for the presentation of more information about vehicles equipped with different drive systems. In particular, parameters such as energy consumption, the possibility of its recovery during braking and the instantaneous power of electric machines were subjected to comparative analysis. Vehicle tests were carried out on a chassis dynamometer in accordance with the WLTP test.

The influence of mounting motors in wheels’ hubs and flexibility of the twist beam rear suspension on their dynamics and strength is presented in the paper. The international roughness indicator (IRI) is applied to assess the overcoming of road unevenness. This indicator is a combination of a shape of the road unevenness and of overcoming velocity. The movement of a wheel’s axis during obstacles overcoming is described. For the needs of the dynamics analysis, the mathematical model of the rear suspension system with embedded motors is developed using the MSC.Adams-ANSYS interface. The discrete model of the twist beam is prepared in the ANSYS software, which is used in the next step to construct the dynamics model of the rear suspension system using the MSC.Adams program. The vertical components of displacement and acceleration of the wheel’s centre, forces in the suspension’s springs and dampers, as well as forces in the joints are analyzed. The analysis of the suspension beam’s stress during the road unevenness overcoming is also carried out.

The article presents an analysis of the impact of a malfunction resulting from excessive clearance on the rocker arm pin of the front suspension on the vehicle’s steerability. The first part of the article presents an analysis of the influence of the clearance on the rocker arm pin on the geometry of the suspension and steering system. The occurrence of forces acting on the rocker arm pin in various phases of the vehicle motion was analyzed. To assess the vehicle’s steering, the vehicle’s response time to sudden steering wheel movement was used. The vehicle’s response time to sudden movement of the steering wheel was used to assess the vehicle’s steerability. The second part presents the results of bench tests and traction tests of a vehicle equipped with a specially made measuring rocker arm with the possibility of simulating a clearance. The tests were carried out on a class B passenger car in selected road tests. The results of measurements obtained for the roadworthy vehicle and the vehicle with the rocker arm with clearance were compared. The influence of the clearance on the rocker arm pin on the change of vehicle steerability in steady and dynamically changing conditions was analyzed. The test results show the effect of clearance on vehicle steering and on the vehicle steerability. The study tried to determine to what extent the clearance on the rocker arm affects the vehicle’s steerability and thus the safety in road traffic.

The dynamics analysis of the rear suspension system of the Fiat Panda III with electric motors mounted in wheels is presented in the paper. The simplified model of this system modeled using the multibody system dynamics method and the MSC. Adams package is proposed. In order to validate the proposed numerical model, the road tests were carried out consisting on passing the vehicle without motors in wheels at constant speed through the obstacle. The vertical displacement of the center of the vehicle wheel was measured during the tests. During the validation, parameters of the wheel-to-road contact, stiffness coefficients of springs and shock absorber damping coefficients of the suspension of the simulation model were modified so that the numerical results were consistent with the experiment. Further, such a tuned model was used to simulate the motion of suspension with the motors mounted into the wheels. The obtained results were validated, obtaining the accepted compatibility. In the following, a series of calculations was carried out in order to analyze the influence of stiffness coefficients of springs and shock absorber damping coefficients on the dynamic response of the suspension.

The article presents the analysis of the impact of reduced damping in the suspension on the change of selected characteristics of vehicle steering. The most important factors influencing the dynamic characteristics of the vehicle steered are described. To this purpose, experimental tests were carried out on a B-class passenger vehicle for selected road tests. These tests were carried out on a vehicle with nominal and reduced damping in the right front wheel suspension. The effect of changing the position of the centre of mass on the behaviour of the vehicle was also taken into account. Comparisons of vehicle test results with standard suspension and with modifications have been carried out. The influence of reduced damping in the suspension on the change of the vehicle steering characteristics in steady and dynamically changing conditions was analysed. In the conducted considerations, the indicators defining the properties of vehicle steerability and stability were used. The determined indicators allowed assessing the impact of the considered changes in the characteristics of the vehicle suspension on its steering and stability of motion.

This paper presents a comparison of the characteristics of the tyres of a full-size vehicle with the tyres of a physical model scaled 1:5. This is a continuation of studies on the use of a scaled vehicle to test the stability of a vehicle. The results presented are based on analysis of a scaled vehicle and a full-size vehicle on a stand and during road tests. Tests were carried out involving manoeuvres based on the ISO standard. The effects of the differences in the construction of the tyres of the scaled vehicle and their impact on the tyre characteristics and its behaviour during testing were compared. This paper presents the results of a comparison of selected parameters of motion for a real vehicle and for a mobile scale model. These tests allowed a statement to be made about the suitability of the used tyres and the entire physical model for lateral stability analysis of a full-size vehicle.