Personal Mobility Devices Research Articles

Design of a Personal Mobility Device for Elderly Users

The ageing society has resulted in imbalances in the population age ratio. The ratio of working-age people was less than that of elderly people resulting in a shortage of elderly caregivers and increased healthcare costs. Although the lifestyle the elderly remains the same, their physical abilities are reduced, requiring them to rely on special equipment when traveling in order to gain more control and safety. Therefore, the Elderly Personal Mobility Device (EPMD) is developed using Internet of Things (IoT) technology to reduce the burden of caregivers, provide freedom and safety for elderly travelers, assess air pollution risks, and alert the occurrence of emergency events. The EPMD is designed in terms of structure, electrical equipment, and sensor systems. First, the shapes, sizes, and thicknesses of the carbon steel used for construction of the EPMD structure are calculated by using SolidWorks software. Next, the electric equipment is carefully selected to meet the requirements of actual use. Finally, the sensor system is designed to monitor the EPMD status and air quality using IoT devices to create a data interface and big data for elderly health service development, as well as an air quality map with distributed measuring stations and a charging station detection system for future use.

Characteristics of injuries according to types of personal mobility devices in a multicenter emergency department from 2011 to 2017: A cross-sectional study.

Personal mobility devices (PMDs) have emerged as new factors in motor vehicle accidents, and related injuries are increasing. We aimed to describe the characteristics of PMD-related injuries presented to emergency departments (EDs) through a cross-sectional study for 7 years.This study is a multicenter cross-sectional study using the Emergency Department-based Injury In-Depth Surveillance database in South Korea. We identified all PMD-related injuries from 2011 to 2017 based on text searching. We categorized them into 3 groups based on their distinguishable characteristics: electric standing scooter (E-scooter), electric self-balancing wheel (E-wheel), and electronic board (E-board).A total of 448 PMD-related injuries were observed during the observation period. E-scooter-, E-wheel-, and E-board-related injuries occurred in 284, 138, and 26 cases, respectively. Most patients were between the ages of 19 and 59 years (69.2%), men (66.3%), and injured because of leisure activity (61.2%). The mechanism of injury was mostly traffic accidents (75.2%), but regarding injuries involving E-wheel and E-board, 25.4% and 30.8% of patients slipped from the device. The most commonly injured body part was the head, which accounted for 58.1% of E-scooter injuries, 38.4% of E-wheel injuries, and 53.9% of E-board injuries. Only 6 of all patients wore a helmet at the time of accident.PMD users and PMD-sharing programs are increasing, and more accidents are expected in the future. As PMDs are convenient to move and more people are willing to use them, proper riding and safety rules based on the type of PMD are needed to reduce the risk of injury. The results of this study can be used as basic data for developing safety policies.

Effects of Human Factors on Public Use of Standing-Type Personal Mobility Vehicle

To significantly reduce the occurrence of severe traffic accidents, reducing the number of vehicles in urban areas should be considered. Personal mobility is essential for realizing this reduction, which requires consideration of the last-/first-mile problem. The overall objective of our research is to solve this problem using standing-type personal mobility vehicles as transportation devices; however, to evaluate the feasibility of such vehicles as future mobility devices, it is necessary to evaluate their operation under real-world conditions. Therefore, in this study, experimental and survey data relating to the velocity, stability, safety, and comfort of a standing-type personal mobility device are obtained to evaluate its performance in three different scenarios. The results show that the personal mobility vehicle is socially well received and can be safely operated on sidewalks, irrespective of the gender or age of the driver; moreover, the results suggest that subjects who routinely use a bicycle are adept at avoiding and absorbing the impacts of small holes and bumps, thereby yielding reduced acceleration values (in all directions) and pitch, roll, and yaw rates. This is anticipated to benefit the future development of personal mobility devices and help realize effective and accessible public transport systems, as well as reduce the number of vehicles in urban areas.

Improvement of Multilevel DC/DC Converter for E-Mobility Charging Station

Considerable efforts are being made to reduce CO2 emissions and thereby solve the problems of environmental pollution and global warming. Technologies for environmentally friendly transportation are being developed using batteries. In particular, with the increase in urbanization and one-person households, e-mobility products are drawing increasing attention as short-distance transportation devices. Among these vehicles, personal mobility devices (PMDs) are receiving attention as new transportation devices that are simple to operate. This paper proposes a new multilevel charging system that is advantageous in responding to the charging voltage specifications of various mobile devices with a single charging system while ensuring a low charging current ripple. The proposed diode-parallel multilevel converter consists of an independent Buck converter in series. The switch of the buck converter is configured at the negative terminal of the input power source so that the gate amplifier voltage is used as the power supply voltage; it can therefore be simply configured without a separate gate amplifier power supply. In addition, it is improved so as to have a wider charging voltage range in a low output voltage region and a better efficiency than the existing diode series multilevel converter. To verify the feasibility of the proposed system, simulations were performed using the software PowerSIM(PSIM), and, in order to verify the validity, a prototype charging system was fabricated to compare and analyze losses according to operating conditions.

Skateboarder and scooter-rider perceptions of the urban environment: a qualitative analysis of user-generated content

ABSTRACT Personal Mobility Devices such as skateboards and scooters are increasingly considered a form of active transportation in dense urban environments. Understanding the experience of users is paramount, especially for cities intent on implementing efficient policies that promote sustainable futures. To meet this need, the research examined the dynamic relationships between the built environment and PMD users in Los Angeles, California. The data used in this study were derived from Instagram posts, and we implemented a participatory digital-photo/diary methodology to investigate how travelers responded to urban features. Our findings suggest that many riders encountered rough surfaces and difficult transitions. Additionally, several built environment types, including well-maintained surfaces, were noted for the relative ease with which they could be ridden. The overall findings tell us that cities need to acknowledge this evidence and apply this toward long-term efforts set on facilitating these active mobilities in an urban setting.

Eco-Efficient Mobility in Smart City Scenarios

Cooperative-Intelligent Transportation Systems (C-ITS) have brought a technological revolution, especially for ground vehicles, in terms of road safety, traffic efficiency, as well as in the experience of drivers and passengers. So far, these advances have been focused on traditional transportation means, leaving aside the new generation of personal vehicles that are nowadays flooding our streets. Together with bicycles and motorcycles, personal mobility devices such as segways or electric scooters are firm sustainable alternatives that represent the future to achieve eco-friendly personal mobility in urban settings. In a near future, smart cities will become hyper-connected spaces where these vehicles should be integrated within the underlying C-ITS ecosystem. In this paper, we provide a wide overview of the opportunities and challenges related to this necessary integration as well as the communication solutions that are already in the market to provide these moving devices with low-cost and efficient connectivity. We also present an On-Board Unit (OBU) prototype with different communication options based on the Low Power Wide Area Network (LPWAN) paradigm and several sensors to gather environmental information to facilitate eco-efficiency services. As the attained results suggest, this module allows personal vehicles to be fully integrated in smart city environments, presenting the possibilities of LoRaWAN and Narrow Band-Internet of Things (NB-IoT) communication technologies to provide vehicle connectivity and enable mobile urban sensing.

The Orthopedic Injury Burden of Personal Mobility Devices in Singapore – Our Experience in the East Coast

PurposePersonal mobility devices (PMDs) have become increasingly popular as a modality of transport worldwide. Starting out as novelty toys, PMDs are gradually being adopted as the mainstream mode of travel. There is an increasing number of accidents involving both PMD riders and other road users since its introduction, leading to a concomitant increase in demand for healthcare resources to manage the injuries. The main objective of this study was to evaluate the inpatient cost and the orthopedic injury pattern due to PMD accidents. MethodsAll patients admitted to the Department of Orthopedic Surgery between December 2016 to February 2018 with injuries due to PMD accidents were recruited. Data collection was performed retrospectively on the demographic profiles, injury patterns, admission related outcomes and expenditures of these patients. Results43 patients were included in this study. The mean duration of admission was 7.81 days and the median cost of admission was S$7835.01 (approximately US$5620). These were comparable to accidents arising from other modes of transport, such as motorcycles and bicycles. In addition, more than 80% of patients were not wearing protective gear at time of accident. These patients had a slightly higher median cost payable per patient as compared to those who donned protective gear, with a difference of S$1669.78 (approximately US$1221). ConclusionThere is a significant health and financial cost to the individual and society from PMD injuries and admission. This can be reduced with strict regulations on PMD use, advocating protective gear use, and promoting awareness on safety measures and the consequences of PMD accidents. The most common injury mechanism and orthopedic injury type for PMD accidents are different from motorcycle accidents.

Orthopedic Injuries Related to Personal Mobility Devices - A Retrospective Observational Study

Orthopedic Injuries Related to Personal Mobility Devices - A Retrospective Observational Study

Design and Implementation of Smart Vest for the Safety of Personal Mobility Device Users

As a solution to the rapid urbanization problem, interest in and use of personal mobility devices such as bicycles and electric kickboards are increasing, and accidents are also rising every year. In this study, a smart vest to prevent traffic accidents and promote safe driving of personal mobility users was designed and implemented. Unlike the existing products on the market that indicate directions using buttons, the smart vest designed and implemented in this study indicates the moving direction by shaking a bracelet and displays the direction by LEDs on the vest. Therefore, this product was designed and implemented to be safer and differentiated from other existing products.

Functional modelling of complex multi-disciplinary systems using the enhanced sequence diagram

This paper introduces an Enhanced Sequence Diagram (ESD) as the basis for a structured framework for the functional analysis of complex multidisciplinary systems. The ESD extends the conventional sequence diagrams (SD) by introducing a rigorous functional flow-based modelling schemata to provide an enhanced basis for model-based functional requirements and architecture analysis in the early systems design stages. The proposed ESD heuristics include the representation of transactional and transformative functions required to deliver the use case sequence, and fork and join nodes to facilitate analysis of combining and bifurcating operations on flows. A case study of a personal mobility device is used to illustrate the deployment of the ESD methodology in relation to three common product development scenarios: (i) reverse engineering, (ii) the introduction of a specific technology to an existent system; and (iii) the introduction of a new feature as user-centric innovation for an existing system, at a logical design level, without reference to any solution. The case study analysis provides further insights into the effectiveness of the ESD to support function modelling and functional requirements capture, and architecture development. The significance of this paper is that it establishes a rigorous ESD-based functional analysis methodology to guide the practitioner with its deployment, facilitating its impact to both the engineering design and systems engineering communities, as well as the design practice in the industry.

Off-stoichiometric TiO2-x-decorated graphite anode for high-power lithium-ion batteries

To meet the growing demand for high-power lithium-ion batteries (LIBs), the development of advanced materials is crucial because they play a central role in energy storage technologies. Although graphite is widely used as the most popular anode material, the rate capability and thermal stability of graphite should be further improved for extending the applications of LIBs into emerging markets like electric vehicles and personal mobility devices. With this in mind, we propose off-stoichiometric TiO2-x-decorated graphite as a potential anode material for practical use in high-power LIBs. Thanks to the high electrical conductivity and thermal resistance of off-stoichiometric TiO2-x induced by an in situ carbothermal reduction process, the rate capability and thermal stability of graphite can be notably enhanced. The TiO2-x-decorated graphite offers a high capacity retention of 76.9% even after 100 cycles at a current density of 1C. We believe that this work can provide more opportunities to explore highly reliable anode materials offering high-energy and high-power characteristics for advanced LIBs.

Injury patterns associated with personal mobility devices and electric bicycles: an analysis from an acute general hospital in Singapore.

The increasing popularity of personal mobility devices (PMDs) and electric bicycles (e-bikes) in Singapore has met with growing public concern over safety. Following the passing of the Active Mobility Bill, there remains a gap in the local literature in terms of injury patterns arising from the use of these devices. A retrospective study was conducted on the Singapore National Trauma Registry (SNTR) from the emergency department of an acute hospital from 1 January 2016 to 31 December 2016. All patients with injuries related to the use of PMDs and e-bikes were included. Data captured included demographic information, device used and injury severity score (ISS). The 259 patients identified had a mean age of 32.1 years and a male predominance. Most (83.4%) were injured from falling off their devices. Devices commonly associated with injury were scooters, skateboards and motorised bicycles. Most injuries were mild (94.6%, ISS < 9) and were mainly external wounds (89.2%) and upper and lower limb injuries (35.5%). There was no difference in ISS in terms of the device used (motorised vs. non-motorised). More severe injuries (ISS ≥ 9) were caused by e-bikes (42.9%) and electric scooters (28.6%). Factors associated with these injuries were older age, use of e-bikes, and injuries to the head, face and thorax. Most patients (86.1%) were discharged and one died. While most injuries associated with PMDs and e-bikes are minor, serious injuries could result from their use. The SNTR should be updated to include PMDs and e-bikes as a category.

Users’ attitudes on electric scooter riding speed on shared footpath: A virtual reality study

Singapore enacted legislation in which off-road footpaths are shared by pedestrians and users of active mobility devices [bicycles, and personal mobility devices such as electric scooter (ES)] since May 2018. From February 2019, the speed limit for active mobility devices on shared footpaths was lowered from 15 km/h to 10 km/h due to frequent incidences of pedestrian-ES crashes. In this study, pedestrian-ES interactive movements along shared footpaths were administered via virtual reality (VR) to 30 subjects as a pedestrian (never rides an ES), and another 30 subjects as an ES rider (rides ES regularly). Ratings were made on perceived degree of safety, feeling of anger (by pedestrians), and celerity of movement (by ES riders), in six VR scenarios: two interaction facings (face-to-face interaction and overtaking) at three ES’ speeds (10 km/h, 15 km/h and 20 km/h). Pedestrian subjects rated ES speeds of 10 km/h and 15 km/h as safer than 20 km/h in overtaking maneuvers, while 15 km/h was rated as safest in face-to-face interactions; the pattern of risk perception is positively correlated with anger level. ES rider subjects rated increasing safety with decreasing riding speed, but 10 km/h was considered to be rather slow. The lack of a clear code of conduct was touted as a key contributory factor in pedestrian-ES crashes.

Multi-Level DC/DC Converter for E-Mobility Charging Stations

The interest in electric-powered transportation has been increased because of problems such as depletion of fossil fuel resources and environmental issues caused by internal combustion engines. The market for various kinds of small E-mobility devices (EMDs), such as electric vehicles (EVs), E-bikes, segways, and mini-boards has been growing rapidly. Of these, the distribution of the small electric vehicles called personal mobility devices (PMDs), which can address problems such as traffic issues and environmental pollution, is expected to gain momentum. However, unlike the widely used charging stations for EVs, charging systems for PMDs are insufficient. The large size of dedicated PMD charging adapters makes them inconvenient to transport. Therefore, to make PMDs more attractive, it is necessary to deploy charging stations that can charge all types of PMDs. The present study proposes a new charging system that can respond to the needs of PMDs having various voltages and implement low charging current ripple. The proposed multi-level charging system can share power by subdividing the power supply to handle the charging requirements of various PMDs. In order to verify the validity of the proposed charging system, we performed simulations and conducted experiments by building a prototype charging system.

Safety assessment of personal mobility devices with different wheel size based on their dynamic stability performance

There has been a rapidly growing trend in the use of small-wheeled personal mobility devices (PMDs) such as small-wheeled electric scooters and bicycles for urban mobility in many cities worldwide. However, it is a well-known fact that most of them do not ride as well as conventional big wheel bicycles, and the ride is often described as 'twitchy', 'wobbly' and 'less stable'. A considerable number of casualties involve single-vehicle accidents which can be correlated to their dynamic stability performance. This paper relates the vehicle frame design with safety performance. By using a well-defined mathematical model, the dynamic stability of different personal mobility devices was compared. The research confirms the lesser stability in existing small wheel electric scooters and bicycles. However, the investigation has also found that the reason is not so much the size of the wheel, but the inadequacy of current design practice to properly account for the complex influence of wheel size on stability. Finally, a case study has been presented to illustrate that current designs of small wheel PMDs can be improved for better stability and safety.

Safety assessment of personal mobility devices with different wheel size based on their dynamic stability performance

There has been a rapidly growing trend in the use of small-wheeled personal mobility devices (PMDs) such as small-wheeled electric scooters and bicycles for urban mobility in many cities worldwide. However, it is a well-known fact that most of them do not ride as well as conventional big wheel bicycles, and the ride is often described as 'twitchy', 'wobbly' and 'less stable'. A considerable number of casualties involve single-vehicle accidents which can be correlated to their dynamic stability performance. This paper relates the vehicle frame design with safety performance. By using a well-defined mathematical model, the dynamic stability of different personal mobility devices was compared. The research confirms the lesser stability in existing small wheel electric scooters and bicycles. However, the investigation has also found that the reason is not so much the size of the wheel, but the inadequacy of current design practice to properly account for the complex influence of wheel size on stability. Finally, a case study has been presented to illustrate that current designs of small wheel PMDs can be improved for better stability and safety.

Hospital Seeing More Personal Mobility Device Accidents and Serious Injuries Despite Active Mobility Act.

Introduction:E-scooters or personal mobility devices (PMDs) have recently been growing in popularity in Singapore. These devices can be especially helpful for those who have reduced mobility or who need to move between several relatively near locations multiples times per day or who simply appreciate the added convenience of having another transportation option. The increasing popularity of PMD has met with growing public concern over safety. Singapore government passed the Active Mobility Act (AMA) in January 2017 to regulate the usage of PMD. In Khoo Teck Puat Hospital, PMD-related accident has increased year on year by 20%–30%. Our study is to compare the incidence and severity of PMD-related accidents before and after the implementation of the AMA.Materials and Methods:A retrospective study of patients presented to the emergency department (ED) of Khoo Teck Puat Hospital for PMD-related accidents between November 2014 and October 2017. In year 1 of the study, we included patients presenting between November 2014 and October 2015. In years 2 and 3, we included patients presenting between November 2015 and October 2016 and November 2016 and October 2017, respectively. Data collected included demographic information, type of device used and impact, outcome, and injury severity score (ISS).Results:A total of 697 PMD-related accidents were seen in our center. We observed an increasing trend of accidents with significant injuries. There were 157 accidents reported in year 1, 233 in year 2, and 307 in year 3. The mean age of patients increased from 28 ± 15 years (range, 5–89 years) in year 1 to 33 ± 15 years (range, 4–83 years). Most patients were males (61.8% in year 1, 76.8% in year 2, and 73.3% in year 3) and Chinese (55.4% in year 1, 62.7% in year 2, and 65.5% in year 3), followed by Malays, Indians, and others. Devices commonly associated with injury were E-scooters, skateboards, and E-bicycles. E-scooters accidents had increased drastically from 12.1% in year 1 to 58.3% in year 3, but E-bicycles and other PMD accidents had decreased in year 3. Most patients were injured from falling off their devices (83.4% in year 1, 83.7% in year 2, and 79.5% in year 3), followed by collisions. Most patients arrived to the ED with own transports and were triaged to the patient acuity category 3 or 4. Most injuries were mild, with ISS <9 (97.5% in year 1 and 94.9% and 94.1% in year 2 and 3, respectively). The most common PMD-related injuries involved external injuries, followed by upper and lower extremities injuries. For more severe injuries (ISS ≥9), the number had increased from 4 in year 1 to 18 in year 3. Most patients were discharged. The number of patients required admissions increased from 12 to 44 in year 3, with two high-dependency or intensive care unit admissions. The mean hospital stay reduced from 5.0 ± 6.0 days to 3.6 ± 4.1 days, with the survival rate remained at 100%. There was only one fatality was reported in year 2.Conclusion:There is an increase in injuries and severity of PMD accidents despite AMA being implemented in January 2017. More need to be done to ensure the safety of PMD-related use in Singapore footpaths and roads.

On-board unit to connect personal mobility vehicles to the IoT

Abstract The basis of smart city services is urban sensing, i.e., the collection of data from sensors deployed in urban settings. However, it has been recently when mobile objects have started to be monitored to feed smart applications within the smart city ecosystems. Most of the advances in this area focus on gathering data from public transportation services such as buses or trams, which use to employ regular cellular or WiFi-based networks and state-of-the-art TCP/IP protocols. Although this covers a basic on-board equipment to report position and other sensor data, there is not a direct integration of Internet of Things (IoT) capabilities in urban transportation and, in general, in moving “things”. Communication technologies used in regular wireless sensor networks such as ZigBee or Bluetooth are not appropriate for high mobility patterns. The Internet of Vehicles (IoV) paradigm aims at filling these gaps, exploiting the synergy between IoT and vehicular networks. It is an emerging area in which extra efforts should be paid to cover constrained capabilities of end devices installed on personal mobility devices, e.g., scooters, segways or bicycles. The solution proposed here deals with the connectivity of moving objects by developing an on-board unit for energy-constrained vehicles, integrating communication capabilities using the Low-Power Wide Area Network (LPWAN) technologies Long Range Wide-area Network (LoRaWAN) and Narrow-Band IoT (NB-IoT) to efficiently collect data. A set of sensors are included to target services in the areas of urban mobility, enhanced environmental perception and speed-up of city operations. The on-board unit has been evaluated through real-life experiments to study especially its communication capabilities with NB-IoT, obtaining good performances in terms of packet delivery ratio and network delay under non-ideal coverage settings. Results show that NB-IoT presents better performances than LoRaWAN, as compared to our previous experiences, with negligible packet loss rates and two-way delays under 100 ms with Internet nodes, at the expense of needing a proper operator network deployment and consuming extra energy due to NB-IoT protocol complexity.

The price of personal mobility: burden of injury and mortality from personal mobility devices in Singapore - a nationwide cohort study

BackgroundPersonal mobility devices (PMDs) like skate-scooters, electric bicycles (e-bikes) or motorised scooters (e-scooters) have become widely available globally. There are several studies describing the rising incidence of injury from such devices. The aim of our study was to examine PMD user factors between motorised (MotPMDs) vs non-motorised PMDs (NonPMDs) as risk factors for severe injury and the need for hospital admission.MethodsWe analysed de-identified National Trauma Registry data (2015 to 2017) from all public sector hospitals in Singapore for patients aged 12 and above presenting to emergency departments with PMD-related injuries. Multivariable logistic regression was used to identify risk factors for the primary outcome of interest (higher injury severity, defined as Injury Severity Score / ISS > =9), and the secondary outcome of interest (need for hospital admission). Additional subgroup analysis was conducted comparing only scooters (manual vs electric), the most common sub-type of PMD in our study.ResultsOf the 614 patients in our study, majority were male (74%), median age 33 years, with 136 (22%) sustaining injuries with ISS > =9; 185 (30%) admitted [median stay length 3 days (IQR: 1–6)] and 93 (15%) required surgery. MotPMDs were more common (480, 78%), with e-scooters being the most common motorised device (393, 64%). There were 6 deaths, all in MotPMD users.On both univariate and multivariable regression, MotPMD users [OR 3.82, 95% CI 1.51–12.9, p = 0.01] and older users (> = 60 years) [OR 9.47, 95% CI 2.45–62.9, p = 0.004] were more likely to sustain injuries with ISS > =9, and more likely to need admission (MotPMD users [OR 1.8, 95% CI 1.04–3.29, p = 0.045], age > =60 years [OR 4.72, 95% CI 1.86–13.0, p = 0.002]).ConclusionMotPMDs tripled the risk of severe injury and doubled the risk of requiring hospitalisation, compared to NonPMDs, likely due to higher travelling speeds. Increased age was also associated with severe injury and requiring hospitalisation.

Context-Based Rider Assistant System for Two Wheeled Self-Balancing Vehicles

Personal mobility devises become more and more popular last years. Gyroscooters, two wheeled self-balancing vehicles, wheelchair, bikes, and scooters help people to solve the first and last mile problems in big cities. To help people with navigation and to increase their safety the intelligent rider assistant systems can be utilized that are used the rider personal smartphone to form the context and provide the rider with the recommendations. We understand the context as any information that characterize current situation. So, the context represents the model of current situation. We assume that rider mounts personal smartphone that allows it to track the rider face using the front-facing camera. Modern smartphones allow to track current situation using such sensors as: GPS / GLONASS, accelerometer, gyroscope, magnetometer, microphone, and video cameras. The proposed rider assistant system uses these sensors to capture the context information about the rider and the vehicle and generates context-oriented recommendations. The proposed system is aimed at dangerous situation detection for the rider, we are considering two dangerous situations: drowsiness and distraction. Using the computer vision methods, we determine parameters of the rider face (eyes, nose, mouth, head pith and rotation angles) and based on analysis of this parameters detect the dangerous situations. The paper presents a comprehensive related work analysis in the topic of intelligent driver assistant systems and recommendation generation, an approach to dangerous situation detection and recommendation generation is proposed, and evaluation of the distraction dangerous state determination for personal mobility device riders.