scholarly journals Automated Curb Recognition and Negotiation for Robotic Wheelchairs

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7810
Author(s):  
Sivashankar Sivakanthan ◽  
Jeremy Castagno ◽  
Jorge L. Candiotti ◽  
Jie Zhou ◽  
Satish Andrea Sundaram ◽  
...  
Keyword(s):  
Human Error ◽  
Controlled Conditions ◽  
Extraction Algorithm ◽  
Sensory Impairments ◽  
Plane Extraction ◽  
Robotic Wheelchairs ◽  
Architectural Barriers ◽  
Robotic Wheelchair

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.

Robust-PCA-based hierarchical plane extraction for application to geometric 3D indoor mapping

2014 ◽  
Vol 41 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Suyong Yeon ◽  
ChangHyun Jun ◽  
Hyunga Choi ◽  
Jaehyeon Kang ◽  
Youngmok Yun ◽  
...  
Keyword(s):  
Principal Component ◽  
Point Clouds ◽  
Previous Method ◽  
Divide And Conquer ◽  
Sensor Data ◽  
Estimation Accuracy ◽  
Content Type ◽  
Extraction Algorithm ◽  
Plane Extraction ◽  
Scan Data

Purpose – The authors aim to propose a novel plane extraction algorithm for geometric 3D indoor mapping with range scan data. Design/methodology/approach – The proposed method utilizes a divide-and-conquer step to efficiently handle huge amounts of point clouds not in a whole group, but in forms of separate sub-groups with similar plane parameters. This method adopts robust principal component analysis to enhance estimation accuracy. Findings – Experimental results verify that the method not only shows enhanced performance in the plane extraction, but also broadens the domain of interest of the plane registration to an information-poor environment (such as simple indoor corridors), while the previous method only adequately works in an information-rich environment (such as a space with many features). Originality/value – The proposed algorithm has three advantages over the current state-of-the-art method in that it is fast, utilizes more inlier sensor data that does not become contaminated by severe sensor noise and extracts more accurate plane parameters.

Negative Obstacle Detection Using LiDAR Sensors for a Robotic Wheelchair

2018 ◽  
Author(s):  
Taylor E. Baum ◽  
Kelilah L. Wolkowicz ◽  
Joseph P. Chobot ◽  
Sean N. Brennan
Keyword(s):  
Time Algorithm ◽  
Detection Algorithm ◽  
Obstacle Detection ◽  
Detection Accuracy ◽  
Time Varying ◽  
Wheelchair Users ◽  
Development Platform ◽  
Robotic Wheelchairs ◽  
Robotic Wheelchair ◽  
Negative Obstacle

The objective of this work is to develop a negative obstacle detection algorithm for a robotic wheelchair. Negative obstacles — depressions in the surrounding terrain including descending stairwells, and curb drop-offs — present highly dangerous navigation scenarios because they exhibit wide characteristic variability, are perceptible only at close distances, and are difficult to detect at normal operating speeds. Negative obstacle detection on robotic wheelchairs could greatly increase the safety of the devices. The approach presented in this paper uses measurements from a single-scan laser range-finder and a microprocessor to detect negative obstacles. A real-time algorithm was developed that monitors time-varying changes in the measured distances and functions through the assumption that sharp increases in this monitored value represented a detected negative obstacle. It was found that LiDAR sensors with slight beam divergence and significant error produced impressive obstacle detection accuracy, detecting controlled examples of negative obstacles with 88% accuracy for 6 cm obstacles and above on a robotic development platform and 90% accuracy for 7.5 cm obstacles and above on a robotic wheelchair. The implementation of this algorithm could prevent life-changing injuries to robotic wheelchair users caused by negative obstacles.

scholarly journals A Multi-Agent Control Architecture for a Robotic Wheelchair

2006 ◽  
Vol 3 (3) ◽  
pp. 179-189 ◽  
Author(s):  
C. Galindo ◽  
A. Cruz-Martin ◽  
J. L. Blanco ◽  
J. A. Fernńndez-Madrigal ◽  
J. Gonzalez
Keyword(s):  
Reinforcement Learning ◽  
Control Architecture ◽  
Daily Lives ◽  
Multi Agent ◽  
Human Skills ◽  
Overall Performance ◽  
Agent Control ◽  
Robotic Wheelchairs ◽  
Assistant Robots ◽  
Robotic Wheelchair

Assistant robots like robotic wheelchairs can perform an effective and valuable work in our daily lives. However, they eventually may need external help from humans in the robot environment (particularly, the driver in the case of a wheelchair) to accomplish safely and efficiently some tricky tasks for the current technology, i.e. opening a locked door, traversing a crowded area, etc. This article proposes a control architecture for assistant robots designed under a multi-agent perspective that facilitates the participation of humans into the robotic system and improves the overall performance of the robot as well as its dependability. Within our design, agents have their own intentions and beliefs, have different abilities (that include algorithmic behaviours and human skills) and also learn autonomously the most convenient method to carry out their actions through reinforcement learning. The proposed architecture is illustrated with a real assistant robot: a robotic wheelchair that provides mobility to impaired or elderly people.

scholarly journals An automated algorithm for online detection of fragmented QRS and identification of its various morphologies

2013 ◽  
Vol 10 (89) ◽  
pp. 20130761 ◽  
Author(s):  
Sidharth Maheshwari ◽  
Amit Acharyya ◽  
Paolo Emilio Puddu ◽  
Evangelos B. Mazomenos ◽  
Gourav Leekha ◽  
...  
Keyword(s):  
Human Error ◽  
Clinical Importance ◽  
Haar Wavelet ◽  
Discrete Wavelet ◽  
Fragmented Qrs ◽  
Automated Algorithm ◽  
Extraction Algorithm ◽  
Gradient Based ◽  
Speed Up ◽  
Diagnosis Therapy

Fragmented QRS (f-QRS) has been proven to be an efficient biomarker for several diseases, including remote and acute myocardial infarction, cardiac sarcoidosis, non-ischaemic cardiomyopathy, etc. It has also been shown to have higher sensitivity and/or specificity values than the conventional markers (e.g. Q-wave, ST-elevation, etc.) which may even regress or disappear with time. Patients with such diseases have to undergo expensive and sometimes invasive tests for diagnosis. Automated detection of f-QRS followed by identification of its various morphologies in addition to the conventional ECG feature (e.g. P, QRS, T amplitude and duration, etc.) extraction will lead to a more reliable diagnosis, therapy and disease prognosis than the state-of-the-art approaches and thereby will be of significant clinical importance for both hospital-based and emerging remote health monitoring environments as well as for implanted ICD devices. An automated algorithm for detection of f-QRS from the ECG and identification of its various morphologies is proposed in this work which, to the best of our knowledge, is the first work of its kind. Using our recently proposed time–domain morphology and gradient-based ECG feature extraction algorithm, the QRS complex is extracted and discrete wavelet transform (DWT) with one level of decomposition, using the ‘Haar’ wavelet, is applied on it to detect the presence of fragmentation. Detailed DWT coefficients were observed to hypothesize the postulates of detection of all types of morphologies as reported in the literature. To model and verify the algorithm, PhysioNet's PTB database was used. Forty patients were randomly selected from the database and their ECG were examined by two experienced cardiologists and the results were compared with those obtained from the algorithm. Out of 40 patients, 31 were considered appropriate for comparison by two cardiologists, and it is shown that 334 out of 372 (89.8%) leads from the chosen 31 patients complied favourably with our proposed algorithm. The sensitivity and specificity values obtained for the detection of f-QRS were 0.897 and 0.899, respectively. Automation will speed up the detection of fragmentation, reducing the human error involved and will allow it to be implemented for hospital-based remote monitoring and ICD devices.

scholarly journals An Approach on Velocity and Stability Control of a Two-Wheeled Robotic Wheelchair

2020 ◽  
Vol 10 (18) ◽  
pp. 6446 ◽  
Author(s):  
Mostafa Nikpour ◽  
Loulin Huang ◽  
Ahmed M. Al-Jumaily
Keyword(s):  
Sliding Mode ◽  
Stability Control ◽  
Main Function ◽  
Velocity Control ◽  
Control Approach ◽  
Power Simulation ◽  
Simulation Results ◽  
Robotic Wheelchairs ◽  
Driving Torque ◽  
Robotic Wheelchair

Conventional robotic wheelchairs (three or four-wheeled) which are statically stable are poor in mobility. Though a two-wheeled robotic wheelchair has better mobility, it is not statically stable and needs an active stability controller. In addition to mobility and stability, velocity control is also important for the operation of a wheelchair. Conventional stability and velocity controllers rely on the motion of the wheels and require high driving torque and power. In this paper, this problem is tackled by adding a compact pendulum-like movable mechanism whose main function is for stability control. Its motion and those of the wheels are controlled through a quasi-sliding mode control approach to achieve a simultaneous velocity and stability control with much less driving torque and power. Simulation results are presented to show the effectiveness of the proposed controller.

Research on the shared control technology for robotic wheelchairs based on topological map

2019 ◽  
Vol 47 (6) ◽  
pp. 825-835
Author(s):  
Fei Wang ◽  
Yuqiang Liu ◽  
Yahui Zhang ◽  
Yu Gao ◽  
Ling Xiao ◽  
...  
Keyword(s):  
Control System ◽  
Shared Control ◽  
Topological Map ◽  
Content Type ◽  
Application Range ◽  
Map Construction ◽  
Scope Of Application ◽  
Interactive Navigation ◽  
Robotic Wheelchairs ◽  
Robotic Wheelchair

Purpose A robotic wheelchair system was designed to assist disabled people with disabilities to walk. Design/methodology/approach An anticipated sharing control strategy based on topological map is proposed in this paper, which is used to assist robotic wheelchairs to realize interactive navigation. Then, a robotic wheelchair navigation control system based on the brain-computer interface and topological map was designed and implemented. Findings In the field of robotic wheelchairs, the problems of poor use, narrow application range and low humanization are still not improved. Originality/value In the system, the topological map construction is not restricted by the environment structure, which helps to expand the scope of application; the shared control system can predict the users’ intention and replace the users’ decision to realize human-machine interactive navigation, which has higher security, robustness and comfort.

scholarly journals A Heuristic Approach to Overcome Architectural Barriers Using a Robotic Wheelchair

2019 ◽  
Vol 27 (9) ◽  
pp. 1846-1854 ◽  
Author(s):  
Jorge L. Candiotti ◽  
Brandon J. Daveler ◽  
Deepan C. Kamaraj ◽  
Cheng S. Chung ◽  
Rosemarie Cooper ◽  
...  
Keyword(s):  
Heuristic Approach ◽  
Architectural Barriers ◽  
Robotic Wheelchair

Maintaining Formation of Multiple Robotic Wheelchairs for Smooth Communication

2016 ◽  
Vol 25 (05) ◽  
pp. 1640005 ◽  
Author(s):  
Ryota Suzuki ◽  
Yoshinori Kobayashi ◽  
Yoshinori Kuno ◽  
Taichi Yamada ◽  
Keiichi Yamazaki ◽  
...  
Keyword(s):  
Elderly Care ◽  
The Elderly ◽  
Wheelchair Users ◽  
Care Workers ◽  
Care Facilities ◽  
Natural Formation ◽  
Traditional Setting ◽  
Robotic Wheelchairs ◽  
Mental And Physical Health ◽  
Robotic Wheelchair

To meet the demands of an aging society, research on intelligent/robotic wheelchairs have been receiving a lot of attention. In elderly care facilities, care workers are required to communicate with the elderly in order to maintain both their mental and physical health. While this is regarded as important, having a conversation with someone on a wheelchair while pushing it from behind in a traditional setting would interfere with their smooth and natural conversation. So we are developing a robotic wheelchair system which allows companions and wheelchair users to move in a natural formation. This paper reports on an investigation to learn the patterns of human behavior when the wheelchair users and their companions communicate while walking together. The ethnographic observation reveals a natural formation of positioning for both companions and wheelchair users. Based on this investigation, we propose a multiple robotic wheelchair system which can maintain desirable formations for communication between wheelchairs.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

An Alternative Method for Identifying a Failed Engine in Twin-Engine Propeller Aircraft

2020 ◽  
Vol 10 (2) ◽  
pp. 103-111
Author(s):  
Andrey K. Babin ◽  
Andrew R. Dattel ◽  
Margaret F. Klemm
Keyword(s):  
Human Error ◽  
Flight Simulator ◽  
Traditional Group ◽  
Aircraft Accidents ◽  
Alternative Method ◽  
Indicator Group ◽  
Group A ◽  
The Dead ◽  
Engine Failure ◽  
And Performance

Abstract. Twin-engine propeller aircraft accidents occur due to mechanical reasons as well as human error, such as misidentifying a failed engine. This paper proposes a visual indicator as an alternative method to the dead leg–dead engine procedure to identify a failed engine. In total, 50 pilots without a multi-engine rating were randomly assigned to a traditional (dead leg–dead engine) or an alternative (visual indicator) group. Participants performed three takeoffs in a flight simulator with a simulated engine failure after rotation. Participants in the alternative group identified the failed engine faster than the traditional group. A visual indicator may improve pilot accuracy and performance during engine-out emergencies and is recommended as a possible alternative for twin-engine propeller aircraft.

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