Accessible Autonomous Transportation and Services: Design Considerations From the Perspective of Consumers and Providers.

OBJECTIVE: To understand the priorities and preferences of people with disabilities (PwDs) and older adults regarding accessible autonomous vehicles (AVs) to address existing transportation barriers. DESIGN: Two national surveys, Voice of the Consumer and Voice of the Provider, were conducted to gather feedback from accessible AV consumers and providers, respectively, in the United States. SETTING: This U.S.-based study focused on PwDs and older adults who may face transportation challenges and those who provide or design AV solutions. PARTICIPANTS: The 922 consumers and 45 providers in the surveys encompassed a diverse range of disability types, caregiver roles, and age groups (N = 967). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The main outcomes were consumer usage needs and provider preferences for features in accessible autonomous transportation. Patterns in usage needs and feature preferences through 2-step clustering algorithm were applied subsequent to the descriptive analysis of participant demographics and their responses. RESULTS: Participants strongly preferred AV features enhancing personal transportation, especially for rural medical appointments. Most sought comprehensive AV automated features. Wheelchair users emphasized accessible entrances, particularly for lower-income brackets ($25,000-$49,000). Provider priorities closely aligned with consumer preferences, reinforcing content validity. CONCLUSIONS: The study highlights the importance of prioritizing wheelchair accessibility in AVs and improving access to medical appointments, especially in rural and low-income communities. Implications include developing inclusive AV services for PwDs and underserved populations. The research establishes a foundation for a more equitable and accessible transportation landscape through AV technology integration.

Accessible autonomous transportation and services: voice of the consumer - understanding end-user priorities.

PURPOSE: This study aimed to explore the requirements for accessible Autonomous Vehicles (AVs) and AV services from a consumer perspective, focusing on people with disabilities (PwDs) and older adults. METHODS: Two national surveys were conducted, capturing current transportation trends and AV priorities. Participants (n = 922) with disabilities and older adults were included in the analysis. RESULTS: Transportation choices exhibited significant divergence based on the underlying causes of disabilities, showcasing distinct inclinations and impediments within each category. AV services, encompassing family conveyance and package delivery, proved integral, but their specific desirability fluctuated in accordance with the nature of disabilities. Notably, medical appointments emerged as the foremost AV utilisation requirement, particularly pronounced among individuals with hearing impairments. Preferences for orchestrating AV rides and the preferred vehicle types displayed disparities linked to the various disability classifications. The employment of mobile applications, websites, and text messages were preferred mediums for arranging rides. Features such as automated route guidance and collision prevention garnered unanimous precedence among AV attributes. Key priorities, spanning wheelchair accessibility, user profiles, and seamless communication with AVs, were universally emphasised across all participant clusters. The study indicated a moderate comfort level with AV deployment, implying the potential for favourable reception within the population of PwDs and older adults. CONCLUSION: The study highlights the significance of considering diverse needs in accessible AV development of vehicle and infrastructure and policies.

The findings inform evidence-based interventions and programmes that prioritise accessibility needs, promoting social inclusion and equitable transportation solutions.Continued research and advocacy are essential for successful autonomous vehicle integration, catering to the needs of all individuals.

Usability and Vibration Analysis of a Low-Profile Automatic Powered Wheelchair to Motor Vehicle Docking System.

The QLX is a low-profile automatic powered wheelchair docking system (WDS) prototype developed to improve the securement and discomfort of wheelchair users when riding in vehicles. The study evaluates the whole-body vibration effects between the proposed QLX and another WDS (4-point tiedown system) following ISO 2631-1 standards and a systematic usability evaluation. Whole-body vibration analysis was evaluated in wheelchairs using both WDS to dock in a vehicle while riding on real-world surfaces. Also, participants rated the usability of each WDS while driving a wheelchair and while riding in a vehicle in driving tasks. Both WDSs showed similar vibration results within the vibration health-risk margins; but shock values below health-risk margins. Fifteen powered wheelchair users reported low task load demand to operate both WDS; but better performance to dock in vehicles with the QLX (p = 0.03). Also, the QLX showed better usability (p < 0.01), less discomfort (p's < 0.05), and greater security compared to the 4-point tiedown while riding in a vehicle (p's < 0.05). Study findings indicate that both WDS maintain low shock exposure for wheelchair users while riding vehicles, but a better performance overall to operate the QLX compared to the 4-point tiedown system; hence enhancing user's autonomy to dock in vehicles independently.

Accessible autonomous transportation and services: a focus group study.

PURPOSE: Existing automated vehicle transportation guidelines and regulations have minimal guidance to address the specific needs of people with disabilities. Accessibility should be at the forefront to increase autonomy and independence for people with disabilities. The purpose of this research is to better understand potential facilitators and barriers to using accessible autonomous transportation. METHODS: Focus groups were conducted with key stakeholders derived from people with disabilities (n = 5), travel companions/caregivers (n = 5), and transportation experts or designers (n = 11). RESULTS: The themes include describing stakeholder perceptions across all three groups by identified themes: autonomous vehicle assistive technology, autonomy vs automation, cost, infrastructure, safety & liability, design challenges, and potential impact. CONCLUSION: Specific gaps and needs were identified regarding barriers and facilitators for transportation accessibility and evidence-based guidance. These specific gaps can help to formulate design criteria for the communication between, the interior and exterior of accessible autonomous vehicles.

Accessible and affordable autonomous transportation may increase mobility and the autonomy of people with disabilities to travel spontaneously.Autonomous vehicles and services should be designed to accommodate various types of disabilities such as multimodal and multilingual device communication.Safety and liability regulatory protocols need to be developed for incidents and emergencies.Wheelchair user, especially people who use powered devices, would need systems for ingress/egress, docking, and occupant restraints.

Evaluation of Power Wheelchair Dynamic Suspensions for Tip Prevention in Non-ADA Compliant Surfaces.

OBJECTIVE: To evaluate the driving performance and usability of a mobility enhancement robot (MEBot) wheelchair with 2 innovative dynamic suspensions compared with commercial electric powered wheelchair (EPW) suspensions on non-American with Disabilities Act (ADA) compliant surfaces. The 2 dynamic suspensions used pneumatic actuators (PA) and electro-hydraulic with springs in series electrohydraulic and spring in series (EHAS). DESIGN: Within-subjects cross-sectional study. Driving performance and usability were evaluated using quantitative measures and standardized tools, respectively. SETTING: Laboratory settings that simulated common EPW outdoor driving tasks. PARTICIPANTS: 10 EPW users (5 women, 5 men) with an average age of 53.9±11.5 years and 21.2±16.3 years of EPW driving experience (N=10). INTERVENTION: Not applicable. MAIN OUTCOME MEASURE(S): Seat angle peaks (stability), number of completed trials (effectiveness), Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), and systemic usability scale (SUS). RESULTS: MEBot with dynamic suspensions demonstrated significantly better stability (all P<.001) than EPW passive suspensions on non-ADA-compliant surfaces by reducing seat angle changes (safety). Also, MEBot with EHAS suspension significantly completed more trials over potholes compared with MEBot with PA suspension (P<.001) and EPW suspensions (P<.001). MEBot with EHAS had significantly better scores in terms of ease of adjustment (P=.016), durability (P=.031), and usability (P=.032) compared with MEBot with PA suspension on all surfaces. Physical assistance was required to navigate over potholes using MEBot with PA suspension and EPW suspensions. Also, participants reported similar responses regarding ease of use and satisfaction toward MEBot with EHAS suspension and EPW suspensions. CONCLUSIONS: MEBot with dynamic suspensions improve safety and stability when navigating non-ADA-compliant surfaces compared with commercial EPW passive suspensions. Findings indicate MEBot readiness for further evaluation in real-world environments.

Analysis of Whole-Body Vibration Using Electric Powered Wheelchairs on Surface Transitions.

Wheelchair users are exposed to whole-body vibration (WBV) when driving on sidewalks and in urban environments; however, there is limited literature on WBV exposure to power wheelchair users when driving during daily activities. Further, surface transitions (i.e., curb-ramps) provide wheelchair accessibility from street intersections to sidewalks; but these require a threshold for water drainage. This threshold may induce high WBV (i.e., root-mean-square and vibration-daily-value accelerations) when accessibility guidelines are not met. This study analyzed the WBV effects on power wheelchairs with passive suspension when driving over surfaces with different thresholds. Additionally, this study introduced a novel power wheelchair with active suspension to reduce WBV levels on surface transitions. Three trials were performed with a commercial power wheelchair with passive suspension, a novel power wheelchair with active suspension, and the novel power wheelchair without active suspension driving on surfaces with five different thresholds. Results show no WBV difference among EPWs across all surfaces. However, the vibration-dose-value increased with higher surface thresholds when using the passive suspension while the active suspension remained constant. Overall, the power wheelchair with active suspension offered similar WBV effects as the passive suspension. While significant vibration-dose-value differences were observed between surface thresholds, all EPWs maintained WBV values below the ISO 2631-1 health caution zone.

Mini-review: Robotic wheelchair taxonomy and readiness.

Robotic wheelchair research and development is a growing sector. This article introduces a robotic wheelchair taxonomy, and a readiness model supported by a mini-review. The taxonomy is constructed by power wheelchair and, mobile robot standards, the ICF and, PHAATE models. The mini-review of 2797 articles spanning 7 databases produced 205 articles and 4 review articles that matched inclusion/exclusion criteria. The review and analysis illuminate how innovations in robotic wheelchair research progressed and have been slow to translate into the marketplace.

Automated Curb Recognition and Negotiation for Robotic Wheelchairs.

Common electric powered wheelchairs cannot safely negotiate architectural barriers (i.e., curbs) which could injure the user and damage the wheelchair. Robotic wheelchairs have been developed to address this issue; however, proper alignment performed by the user is needed prior to negotiating curbs. Users with physical and/or sensory impairments may find it challenging to negotiate such barriers. Hence, a Curb Recognition and Negotiation (CRN) system was developed to increase user's speed and safety when negotiating a curb. This article describes the CRN system which combines an existing curb negotiation application of a mobility enhancement robot (MEBot) and a plane extraction algorithm called Polylidar3D to recognize curb characteristics and automatically approach and negotiate curbs. The accuracy and reliability of the CRN system were evaluated to detect an engineered curb with known height and 15 starting positions in controlled conditions. The CRN system successfully recognized curbs at 14 out of 15 starting positions and correctly determined the height and distance for the MEBot to travel towards the curb. While the MEBot curb alignment was 1.5 ± 4.4°, the curb ascending was executed safely. The findings provide support for the implementation of a robotic wheelchair to increase speed and reduce human error when negotiating curbs and improve accessibility.

Curb Negotiation With Dynamic Human-Robotic Wheelchair Collaboration.

Wheelchair users often face architectural barriers such as curbs, limiting their accessibility, mobility, and participation in their communities. The mobility enhancement robotic (MEBot) wheelchair was developed to navigate over such architectural barriers. Its application allows wheelchair users to negotiate curbs automatically while the user remains in control. The application was optimized from a manual to a semiautomated process based on wheelchair users' feedback. The optimized application was evaluated by experienced wheelchair users who navigated over curbs of different heights. Participants evaluated MEBot in terms of effectiveness, workload demand, and usability. Ten participants successfully ascended and descended curbs of different heights at an average completion time of 55.7 ± 19.5 and 30.3 ± 9.1 s, respectively. MEBot maintained stability during the process, while participants reported low levels of effort, frustration, and overall cognitive demand to operate MEBot. Furthermore, participants were satisfied with the ease of learning and using the MEBot curb negotiation application to overcome the curbs but suggested less wheel adjustment for comfort and a faster pace to overcome curbs during real-world conditions.

Improving wheelchair route planning through instrumentation and navigation systems.

Route planning is an important tool to reach points of interest. The current technology offers options for public transportation and pedestrians on the road and sidewalks, respectively. However, for people who use electric powered wheelchairs (EPW) as their primary means of mobility, the level of accessibility and EPW battery consumption are important during route planning. This paper introduces the concept of an accessible route navigation application to reduce EPW battery consumption. The application, called eNav, uses five layers of information including OpenStreetMaps (OSM), airborne laser scanner (ALS), Point-of-Interests (POIs), public transportation, and crowdsourcing. eNav collects these layers of information to provide the shortest, most accessible, and most comfortable routes that consume the least amount of EPW battery. Additionally, the paper presents the Mobility Enhancement roBot (MEBot), a legged-wheeled power wheelchair, to drive over architectural barriers and less accessible environments. The paper proposes the use of MEBot as a sixth layer of information to inform eNav and road authorities about sidewalk/route conditions, to improve road accessibility, and to provide an energy efficient route planning for non-MEBot users.

Usability evaluation of attitude control for a robotic wheelchair for tip mitigation in outdoor environments.

Tips and falls are the most prominent causes of wheelchair accidents that occur when driving on uneven terrains and less accessible environments. The Mobility Enhancement Robotic Wheelchair (MEBot) was designed to improve the stability of Electric Powered Wheelchairs (EPW) when driving over these environments. MEBot offers six independently height-adjustable wheels to control attitude of its seat over uneven and angled terrains. Its attitude control application uses an inertial measurement unit to detect seat angles changes to adjust each wheel-height accordingly. MEBot was compared to commercial EPWs in terms of EPW performance (seat angle changes and response time) and participant perception (satisfaction and task-load demand) towards each device. Ten participants drove their own EPW and MEBot for five trials each through driving tasks that replicated outdoor environments. Results showed less change in the pitch angle when driving up and down a 10° slope using MEBot (5.6 ± 1.6°, 6.6 ± 0.5°) compared to the participants' own EPW (14.6 ± 2.6°, 12.1 ± 2.6°). However, MEBot required 7.8 ± 3.0 s to self-adjust to the minimum angle when driving over the tasks. Participants reported no difference in satisfaction and task load demand between EPWs due to similarities in comfort and ease-of-use. Improving the speed and efficiency of MEBot's attitude control application will be addressed in future work based upon participants' feedback.

A Heuristic Approach to Overcome Architectural Barriers Using a Robotic Wheelchair.

The Mobility Enhancement roBotic (MEBot) wheelchair was developed to improve the safety and accessibility of wheelchair users when facing architectural barriers. MEBot uses pneumatic actuators attached to its frame and six wheels to provide curb ascending/descending for heights up to 20.3 cm. To improve MEBot's application, this study used a heuristic approach with power wheelchair users to evaluate and improve the MEBot application at different curb heights. Wheelchair users were trained on MEBot's features to operate its curb ascending/descending application. Three trials were carried out with wheelchair users ascending and descending three curbs of different height. Quantitative variables were analyzed to improve the sequential steps to ascend/descend curbs. Additionally, the application's effectiveness and efficiency were measured by the number of completed tasks, change in seat angle, and task completion time. Results showed that participants completed each trial and applied alternative strategies to traverse different curb heights. Furthermore, results suggested the combination and/or re-arrangement of steps to reduce task completion time. MEBot demonstrated its effectiveness to ascend/descend different curb heights with a heterogeneous participant sample. Future work will incorporate participant's most efficient strategies to improve the ascending/ascending process and the efficiency of the MEBot application.

Usability Evaluation of a Novel Robotic Power Wheelchair for Indoor and Outdoor Navigation.

OBJECTIVE: To compare the Mobility Enhancement roBotic (MEBot) wheelchair's capabilities with commercial electric-powered wheelchairs (EPWs) by performing a systematic usability evaluation. DESIGN: Usability in effectiveness, efficacy, and satisfaction was evaluated using quantitative measures. A semistructured interview was employed to gather feedback about the users' interaction with MEBot. SETTING: Laboratory testing of EPW driving performance with 2 devices in a controlled setting simulating common EPW driving tasks. PARTICIPANTS: A convenience sample of expert EPW users (N=12; 9 men, 3 women) with an average age of 54.7±10.9 years and 16.3± 8.1 years of EPW driving experience. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Powered mobility clinical driving assessment (PMCDA), Satisfaction Questionnaire, National Aeronautics and Space Administration's Task Load Index. RESULTS: Participants were able to perform significantly higher number of tasks (P=.004), with significantly higher scores in both the adequacy-efficacy (P=.005) and the safety (P=.005) domains of the PMCDA while using MEBot over curbs and cross-slopes. However, participants reported significantly higher mental demand (P=.005) while using MEBot to navigate curbs and cross-slopes due to MEBot's complexity to perform its mobility applications which increased user's cognitive demands. CONCLUSIONS: Overall, this usability evaluation demonstrated that MEBot is a promising EPW device to use indoors and outdoors with architectural barriers such as curbs and cross-slopes. Current design limitations were highlighted with recommendations for further improvement.