The article concerns the issue of retrofitting (i.e., the conversion of worn-out diesel buses into electric buses). As this solution is often cheaper than purchasing new electric buses, it can be attractive for low-population areas with a weaker economic infrastructure. The article aims to present an original method for rapidly selecting components for the electric traction system, such as the electric motor, inverter, and transmission systems, combined with a battery installed in a drawer. The battery swapping solution is dedicated to regions with underdeveloped power infrastructure that does not allow for fast charging of bus batteries using pantographs. A mathematical model in the form of a polynomial was developed to estimate the energy losses for a given route. This model consists of a bus physics model, an energy loss model in the propulsion system, and a battery model. The weight coefficients of the polynomials were determined based on an analytical analysis of the model dependencies. The obtained models were reduced using the Lasso regularization method in linear regression. The input data for the model includes route characteristics (or driving cycle) and technical characteristics of the traction system components. The model output provides a detailed profile of electric energy consumption and peak values of the drive system characteristics (e.g., maximum torque of the motor) which must not be exceeded. Implemented as computer software, the model—combined with a database of motors, inverters, drive transmission systems, and batteries—allows for a quick calculation of the possibilities of applying a selected configuration to cover a given route. The approach proposed in the article enables the rapid composition of electric traction devices based on required driving conditions during the initial vehicle prototyping stage. At the same time, it allows the state of the bus battery to be monitored and estimates the remaining range during the operation of upgraded buses.
1 September 2013 in Bulletin Of The Polish Academy Of Sciences-Technical Sciences
Here we present one of the more complex models for studying the stability of driving an electric car with electromechanical differential systems. The purpose of simulation is to choose a structure of the control system for a velocity control on driven wheels (an algorithm of a differential) most appropriate for the driver. This type of goal is particularly important in the case of a disabled driver sitting in a wheelchair. The modeling takes into account both the mechanical and electric structure of the vehicle, and finally the human element - a simple model of human impact on the steer by a wire system. Modeling and simulation have used MBS package (SimMechanics). The results of the simulation have showed the best algorithms of an electromechanical differential for the velocity control of rear drive wheels: with setting a velocity difference or with an average velocity controller in the point A of the centre of a car front axle.
The article discusses the issue of how potential users perceive automated and autonomous vehicle (AV) technology, emphasizing that its sophistication and reliability are crucial for the safety of driving vehicles with a level of automation starting from the third degree. Safety plays a significant role in determining public acceptance of autonomous vehicles. Without the acceptance of potential users and their willingness to use smart electric vehicles, it is challenging to talk about the rapid implementation of autonomous vehicles, despite their undeniable benefits. The article presents an analysis of survey results regarding public opinion in Poland on this matter. The survey utilized various methods, including CAWI surveys, Focus Group Interviews (FGI), and Individual In-depth Interviews (IDI). The CAWI survey involved 1067 respondents in Poland, with a 95% confidence level and a maximum margin of error of 3%, representing a representative sample of the Polish population aged 16 and above. The article examines issues that illustrate respondents’ acceptance levels concerning perceived security and trust in AVs. The obtained results are compared with opinions from surveys conducted in other countries. Additionally, the article attempts to identify reasons for the low assessment of the technologies among respondents and proposes measures to boost confidence in automated and autonomous vehicles.
Are the regulations relating to electromagnetic compatibility (EMC) sufficient to ensure the safety of all autonomy systems? EMC is one of the critical factors influencing the proper functioning of a vehicle and its safety. However, the safety of autonomous vehicles from the perspective of EMC has not been comprehensively researched to date. The purpose of this article is to evaluate whether the currently imposed requirements are adequate. To assess research methods and requirements, it is necessary to determine the electromagnetic environment of vehicles. For this purpose, identification tests of the vehicle’s operating environment were conducted. The article presents the results of research on both the internal and external electromagnetic environments of vehicles. These studies were carried out using normative methods. Despite the significant importance of EMC and the existence of defined normative requirements, the results of the conducted research indicate that some devices available on the market, including those unrelated to vehicle autonomy, fail to meet these standards. Consequently, devices responsible for vehicle safety must be resistant to such electromagnetic exposures. In extreme cases, the malfunction of a single vehicle component due to inadequate electromagnetic compatibility could lead to the disruption of vehicle functions or driver disorientation. Such occurrences pose a direct threat to road traffic safety and the well-being of passengers.
The subject of this article is the design of a nonstandard steering system in cars. The applied methodology takes into account universal design, ensuring the greatest possible adaptation of the steering system to potential users, and at the same time, thanks to the specific nature of the designed steering device, it also assumes a special approach allowing for individual adjustment of the steering system to the needs and limitations of drivers with lower-limb disabilities. It is implemented through the “custom design” methodology. This article presents the impact of the design features of the multifunction steering wheel on the correctness of driving, as well as the level of load on selected muscles of the upper limbs responsible for operating the steering wheel. The tests were carried out on a dynamic simulator of a motor vehicle using the electromyography (EMG) technique, which enables the measurement of muscle load. A systemic approach to training and verifying the skills of drivers using new HMI solutions is proposed.
1 February 2019 in Transportation Research Part F: Traffic Psychology and Behaviour