Mini Vehicles Research Articles

An Automobile's Tail Lights: Sacrificing Safety for Playful Design?

The counterintuitive "Union Jack"-inspired turn signals on versions of BMW's Mini vehicles was investigated to reveal potential impacts on human performance. When some Mini drivers indicate a change in direction, they do so with an oppositely oriented arrow. This conflict, between the task-irrelevant spatial shape and task-relevant location of the signal, mimics a "converse" spatial-Stroop effect that, in combination with the ubiquitous use of arrows on road signs, may be confusing. Participants (n = 30) responded-via right and left keypresses-to the directions of road signs and turn signals in both pure and mixed blocks. Reaction times and accuracies were recorded to determine performance in each condition (compatible, neutral, incompatible). Performance suffered when the location and direction of the stimuli did not correspond. When responding to turn signals the cost to performance was especially salient in mixed blocks. Thus, when driving on roads where the meanings of arrows on road signs is important, turn signals pointing in a direction opposite from the directional intention indicated by the signals' location are likely to be confusing. The design of some Mini's "Union Jack" style taillights opposes well-established principles of cognitive functioning, caused confusion in our laboratory study and therefore may be a safety hazard-a possibility that ought to be explored in more realistic (e.g., driving simulator) situations. BMW designers should consider universally adopting the neutral, "horizontal line," illumination style that is currently available in the aftermarket.

Real-Time Lane Line Tracking Algorithm to Mini Vehicles

Abstract Autonomous navigation is important not only in autonomous cars but also in other transportation systems. In many applications, an autonomous vehicle has to follow the curvature of a real or artificial road or in other words lane lines. In those application, the key is the lane detection. In this paper, we present a real-time lane line tracking algorithm mainly designed to mini vehicles with relatively low computation capacity and single camera sensor. The proposed algorithm exploits computer vision techniques in combination with digital filtering. To demonstrate the performance of the method, experiments are conducted in an indoor, self-made test track where the effect of several external influencing factors can be observed. Experimental results show that the proposed algorithm works well independently of shadows, bends, reflection and lighting changes.

A Study on the Market Environment and Characteristics of Japan’s Mini Vehicles Industry

Purpose: In this paper, we analyzed the secrets of popularity, characteristics of users, usage status, and social utility of mini vehicles in Japan. The key points revealed on this basis are as follows. Research design, data, and methodology: Japan’s auto sales market was about 40% for mini vehicles, 55% for general cars and 5% for imported cars. Sales of mini vehicles were also in high demand, accounting for one-third of the global market. The number of mini vehicles owned exceeded 30 million units as of 2019, accounting for about 40% of the total number of cars owned. The main owner of the mini vehicles was “Women” and was an important means of daily transportation such as commuting and shopping. Results: Japan’s mini vehicles were manufactured to reflect social and cultural characteristics, making them a “non-tariff barriers” for foreign car makers. The biggest factor in the popularity of mini vehicles was “economic feasibility.” The cost of maintenance (taxes) and purchase of vehicles was lower than that of general cars. The next most important thing for consumers was the convenience of use, such as the convenience of driving narrow roads and parking. For people living in rural areas, mini vehicles were replacing public transportation. Therefore, mini vehicles were a valuable life line in rural areas. Implications: Mini vehicles were making huge contributions to employment. About 20% of the total auto production was mini vehicles, all of which were produced in Japan. The impact on road damage was also much smaller than that of general cars, contributing to social cost savings.

A Study on the Market Environment and Characteristics of Japan’s Mini Vehicles Industry

A Study on the Market Environment and Characteristics of Japan’s Mini Vehicles Industry

Optimization and testing of suspension system of electric mini off-road vehicles.

Mini vehicles with a small wheelbase are extremely sensitive to road roughness. The aim of this study is to explore the influence of road information on ride comfort and enhance the ride comfort of mini vehicles. According to the 5-degree-of-freedom vibration model of an electric mini off-road vehicle, the partial differential matrix equation of system motion is established using the Lagrange method, and the frequency response characteristic of the system is analyzed. The input matrix of pavement unevenness is obtained by considering the mutual power spectrum density between front and rear wheels. Road surface roughness information is obtained using an instrument for measuring road roughness. A comprehensive objective function and a constraint condition are established for comfort and safety. Based on the parameters obtained through the optimum design of a 1/4 vehicle model, the optimized stiffness and damping coefficient of suspension are obtained using a MATLAB optimization program. The law of the vibration performance of off-road vehicles with respect to suspension stiffness and the damping coefficient is obtained through the analysis of optimized results. A driving simulation and a test are conducted on the electric mini off-road vehicle. The results show that the use of the measured pavement data as simulation input is closer to the actual situation and provides higher accuracy compared to the simulated pavement model. According to the optimization and test results, the parameters optimized by a 1/2 vehicle (5 degrees of freedom) vibration model are better than those optimized by the 1/4 vehicle vibration model. The optimization results confirm reduction in acceleration, acceleration power spectrum density, and the root mean square of the weighted acceleration of the seat. This shows that the electric mini off-road vehicle provides better ride comfortability after optimization.

Investigation of the suspension design and ride comfort of an electric mini off-road vehicle

In view of the little research that has been conducted on the ride comfort of mini vehicles, an electric mini off-road vehicle was designed in this study and a 2 degree-of-freedom quarter car model was established to investigate the ride comfortability. The amplitude-frequency and vibration response characteristics of the suspension were analyzed with the natural frequencies of the front and rear suspensions selected in accordance with the required driving performance. A comprehensive objective function with respect to the safety and comfortability was established, and the damping ratio of the suspension was determined. The damping characteristics of the shock absorber were analyzed to derive an adjustment rule of the suspension damping ratio. The piecewise linear speed characteristics of the shock absorber were subsequently obtained, and suspension-parameter identification and ride comfort tests were conducted. The test results showed that the natural frequencies and damping ratios of the front and rear suspensions were 1.676 and 1.922 Hz, and 0.225 and 0.242, respectively. The results of a pulse input test and D-level road random running test also demonstrated the safety and good ride comfortability of the vehicle.

Real-Time Feedback Impacts on Eco-Driving Behavior and Influential Variables in Fuel Consumption in a Lisbon Urban Bus Operator

The main purposes of this research were, in a first stage, to assess the impacts of real-time feedback on the driving behavior of bus drivers, considering vehicle age and type and drivers experience and, in a second stage, to identify the main influential variables in fuel consumption. Data was collected with an on-board device used by a Portuguese urban bus transport operator. Significant increases in the performance of undesirable events were observed without real-time feedback, followed by decreases with the restart of real-time feedback. Higher increases (between 6% and 170%) were observed when driving Mini vehicles in comparison with other bus types, particularly in extreme accelerations, excess rpm, extreme braking, and hard starts. Furthermore, a General Linear Model was applied to assess the most influential variables on fuel consumption. Vehicle type and age are the most influential variables on fuel consumption, with minibuses presenting higher increases when compared with standard buses. Increases up to 3% were observed leading to an extra 3769 liters of fuel consumed when feedback was not provided. Decreases in fuel consumption between 0.3% and 2% were observed with real-time feedback, avoiding the consumption of 4280 L of fuel. The results obtained in this paper provide bus companies with insightful information for the development of future operational strategies and training programs.

607 軽自動車の将来性に関する研究

607 軽自動車の将来性に関する研究