51873371
Assistive Handlebar Based on Tactile Sensors: Control Inputs and Human Factors
Tactile sensors can be used to build human-machine interfaces, for instance in isometric joysticks or handlebars. When used as input sensor device for control, questions arise related to the contact with the human, which involve ergonomic aspects. This paper focuses on the example application of driving a powered wheelchair as attendant. Since other proposals use force and torque sensors as control input variables, this paper explores the relationship between these variables and others obtained from the tactile sensor. For this purpose, a handlebar is instrumented with tactile sensors and a 6-axis force torque sensor. Several experiments are carried out with this handlebar mounted on a wheelchair and also fixed to a table. It is seen that it is possible to obtain variables well correlated with those provided by force and torque sensors. However, it is necessary to contemplate the influence of issues such as the gripping force of the human hand on the sensor or the different kinds of grasps due to different physical constitutions of humans and to the inherent random nature of the grasp. Moreover, it is seen that a first step is necessary where the contact with the hands has to stabilize, and its characteristics and settle time are obtained.
14547307
Haptic Control for the Interactive Behavior Operated Shopping Trolley InBOT
An important challenge in service robotics is to design user interfaces that can be used intuitively to enable the potential users to benefit from the robot’s functionalities. These interfaces have to be easy to understand on the one hand but have to be able to access the various features that are provided by robotics. This document presents the haptic-based control of an Interactive Behavior Operated shopping Trolley (InBOT). The holonomic robot InBOT is an approach to transfer state of the art robotics technology into all-day environments to make their benefits available for the populace. The haptic-based mode of control enables the user to steer InBOT just like an ordinary shopping cart while being released from the burden to push the cart with muscle power. Additionally haptic commands are introduced which the user can give the robot using the haptic handle. These commands are classified by a vector support machine and activate corresponding behaviors of the robot’s advanced behavior repertoire. Finally the user is supported continuously by features from the robot’s basic behavior repertoire like the avoidance of obstacles.
49653098
Tactile Sensor-Based Steering as a Substitute of the Attendant Joystick in Powered Wheelchairs
Attendant joysticks of powered wheelchairs are devices oriented to help caregivers. Diseases and disabilities such as dementia, spinal cord injuries or blindness make the user unable to drive the chair by his or her own. However, this device is not intuitive to use, especially for old people. Proper processing of the information provided by two tactile sensors in the handlebar achieves control signals that allow an easy and intuitive driving. This is done in this paper, where the performance of this approach is evaluated in comparison with that of the joystick by means of objective measurements as well as questionnaires to obtain the subjective perception of the participants in the experiments. The results show a better performance of the handlebar in terms of error in following a trajectory, collisions with the surrounding furniture, and user feeling related to ease of use, comfort, required training, usefulness, safety, and fatigue.
8208790
Admittance control based walking support and power assistance of an omnidirectional wheelchair typed robot
Up to now, many robotic aids for the elderly's walking support or the disabled's walking rehabilitation are reported, and numerous electrical-powered wheelchairs are developed. In this paper, a new kind of omnidirectional wheelchair typed robot is developed. The robot not only can accomplish the walking support or walking rehabilitation as the elderly or the disabled walking, but also can realize the power assistance for a caregiver when he/she pushes the robot to move. The basic structure of the robot is described and an admittance based human-machine interaction controller is introduced for power assistance. Experiments are implemented, and the experimental results show that the pushing force can be reduced and well controlled arbitrarily in all directions as designed. The development purposes of the robot for walking support and power assistance are achieved.
109977974
Development of power-assisted attendant-propelled wheelchair
Attendant propelled wheelchairs are driven by people who often feel necessity for power assistance while pushing them up or going down on ramps, sideslopes or curbs. We propose a novel power-assisted wheelchair with a force sensing mechanism. A DC motor and a differential gear are employed. The power assistance is controlled as if it were always operated on a solid flat ground. The control algorithm is based on a model reference adaptive control (MRAC). A prototype was made and initially tested. It was found effective to reduce operator's driving force.
39793152
Development of collision avoidance supporting system for power assist system in omni-directional mobile robot
In the omni-directional wheelchair, the power assist system for the attendant is effective for persons who don't have enough power, such as the elderly people and disabled people. In addition, it is difficult for a novice operator to navigate an omni-directional wheelchair through a narrow space like an elevator door or a path along the wall because it is always necessary to keep in mind the width of the vehicle. Such navigation can give stress to the operator. In those cases, an operational assistant system that appeals to human's haptic sensation can be useful. In this paper, a novel operational assistant system using laser scanning sensor in the power assist system is proposed for the omni-directional wheelchair. The present operational assistant system adopts a power assist system using the handle with 6-DOF force/torque sensor in order to the induce operator spontaneously evading obstacle.
1001186
Driving Interface Based on Tactile Sensors for Electric Wheelchairs or Trolleys
This paper introduces a novel device based on a tactile interface to replace the attendant joystick in electric wheelchairs. It can also be used in other vehicles such as shopping trolleys. Its use allows intuitive driving that requires little or no training, so its usability is high. This is achieved by a tactile sensor located on the handlebar of the chair or trolley and the processing of the information provided by it. When the user interacts with the handle of the chair or trolley, he or she exerts a pressure pattern that depends on the intention to accelerate, brake or turn to the left or right. The electronics within the device then perform the signal conditioning and processing of the information received, identifying the intention of the user on the basis of this pattern using an algorithm, and translating it into control signals for the control module of the wheelchair. These signals are equivalent to those provided by a joystick. This proposal aims to help disabled people and their attendees and prolong the personal autonomy in a context of aging populations.
31244764
A Survey on Perception Methods for Human–Robot Interaction in Social Robots
For human–robot interaction (HRI), perception is one of the most important capabilities. This paper reviews several widely used perception methods of HRI in social robots. Specifically, we investigate general perception tasks crucial for HRI, such as where the objects are located in the rooms, what objects are in the scene, and how they interact with humans. We first enumerate representative social robots and summarize the most three important perception methods from these robots: feature extraction, dimensionality reduction, and semantic understanding. For feature extraction, four widely used signals including visual-based, audio-based, tactile-based and rang sensors-based are reviewed, and they are compared based on their advantages and disadvantages. For dimensionality reduction, representative methods including principle component analysis (PCA), linear discriminant analysis (LDA), and locality preserving projections (LPP) are reviewed. For semantic understanding, conventional techniques for several typical applications such as object recognition, object tracking, object segmentation, and speaker localization are discussed, and their characteristics and limitations are also analyzed. Moreover, several popular data sets used in social robotics and published semantic understanding results are analyzed and compared in light of our analysis of HRI perception methods. Lastly, we suggest important future work to analyze fundamental questions on perception methods in HRI.
6246772
Textile Pressure Mapping Sensor for Emotional Touch Detection in Human-Robot Interaction
In this paper, we developed a fully textile sensing fabric for tactile touch sensing as the robot skin to detect human-robot interactions. The sensor covers a 20-by-20 cm2 area with 400 sensitive points and samples at 50 Hz per point. We defined seven gestures which are inspired by the social and emotional interactions of typical people to people or pet scenarios. We conducted two groups of mutually blinded experiments, involving 29 participants in total. The data processing algorithm first reduces the spatial complexity to frame descriptors, and temporal features are calculated through basic statistical representations and wavelet analysis. Various classifiers are evaluated and the feature calculation algorithms are analyzed in details to determine each stage and segments’ contribution. The best performing feature-classifier combination can recognize the gestures with a 93.3% accuracy from a known group of participants, and 89.1% from strangers.
20429469
A Distributed Tactile Sensor for Intuitive Human-Robot Interfacing
Safety of human-robot physical interaction is enabled not only by suitable robot control strategies but also by suitable sensing technologies. For example, if distributed tactile sensors were available on the robot, they could be used not only to detect unintentional collisions, but also as human-machine interface by enabling a new mode of social interaction with the machine. Starting from their previous works, the authors developed a conformable distributed tactile sensor that can be easily conformed to the different parts of the robot body. Its ability to estimate contact force components and to provide a tactile map with an accurate spatial resolution enables the robot to handle both unintentional collisions in safe human-robot collaboration tasks and intentional touches where the sensor is used as human-machine interface. In this paper, the authors present the characterization of the proposed tactile sensor and they show how it can be also exploited to recognize haptic tactile gestures, by tailoring recognition algorithms, well known in the image processing field, to the case of tactile images. In particular, a set of haptic gestures has been defined to test three recognition algorithms on a group of users. The paper demonstrates how the same sensor originally designed to manage unintentional collisions can be successfully used also as human-machine interface.
23351703
Two-Dimensional Direction Recognition Using Uniaxial Tactile Arrays
To allow intuitive communication in human-robot cooperation through tactile information, this paper presents a method to recognize human intended direction in 2-D using a handlebar equipped with uniaxial tactile arrays. The method first extracts various features from the tactile images aiming to reduce computation complexity and increase recognition robustness. A support vector machines classifier was implemented for classifying the intended direction of humans using the extracted features. The algorithm efficiency of using different combinations of features has been investigated and compared through human user studies. In total, five human users in the project team were involved in this research. Experimental results show that the proposed method can achieve 91.7% recognition accuracy if both the training data and validation data contain tactile images from all the users. The method could still achieve 77.5% recognition accuracy when the training and validation data share no common user.
35729734
User intention estimation by grip sensor for cane-type walking support robot
Is this study, to assist walking motion for elderly people and disabled people, robotics-based assist technologies are important. Toward to realize such technologies, we have developed cane-type walking assist robot. In the paper, we proposed user intuitive assist technique by using a grip sensor. The proposed technique is evaluated through a preliminary experiment.
37447630
Occlusion Handling in Video-Based Augmented Reality Using the Kinect Sensor for Indoor Registration
Video-based Augmented Reality (VAR) aims to add 3D virtual objects (3D VOs) to a real world video sequence, in order to provide additional and useful information to facilitate some tasks, like computer aided surgery, simulation in a real environment, satellite positioning, interior design, among others. To achieve a consistent and convincing augmented scene, it is necessary that the VOs are properly occluded by real objects (Occlusion Problem in VAR); in this paper, we present a strategy based on the use of the Kinect sensor to solve this problem. In the occlusion stage we evaluate distances between real and VOs. Then, the parts of the VO occluded by a real object are calculated and removed. We found that the Kinect sensor is appropriate to be used for handling occlusions in indoor environments, dynamic scenarios and real-time applications. Experiments showed comparable results with the state of the art in both issues: occlusion handling and processing time.
34232322
Occlusion Detection and Localization from Kinect Depth Images
Faces captured in a real-world scenario may suffer from large variations in shape and occlusions due to difference in illumination, variation in pose and orientation of a facial image. Automated face recognition or security reinforcement by surveillance techniques would be useless if the faces are occluded. Therefore, face occlusion detection has become very important not only for effective face recognition but also to prevent security threats. In this paper, for the very first time an occlusion detection method is proposed based on the depth information provided by Kinect RGB-D cameras. Uniform Local Binary Pattern (LBP) is used to effectively extract the features from the depth images and SVM binary classifier is then applied to identify the front face and the occluded face. For localizing occluded regions in the face image, a threshold based approach is proposed to identify the areas close to the camera. In the depth images, an object close to the camera has a higher pixel intensity than the object further from the camera. Thus, we assume that occluded regions have lower distance from the camera, i.e. higher intensity values. Based on this hypothesis, we extract the connected component with highest energy values as the potential occluded region from the depth image. The boundary of the detected occluded region is then corrected using the reference front face image. The occlusion detection and localization method have been evaluated on EUROKOM Kinect face database containing different types of occluded and unoccluded faces with neutral expressions. Experimental results show that the proposed method provides an average detection rate of 98.50% for front and occluded face images. We have also compared our proposed method with existing methods that use faces acquired using 3D scanners for occlusion detection.
1924791
Directions Toward Effective Utilization of Tactile Skin: A Review
A wide variety of tactile (touch) sensors exist today for robotics and related applications. They make use of various transduction methods, smart materials and engineered structures, complex electronics, and sophisticated data processing. While highly useful in themselves, effective utilization of tactile sensors in robotics applications has been slow to come and largely remains elusive today. This paper surveys the state of the art and the research issues in this area, with the emphasis on effective utilization of tactile sensors in robotic systems. One specific with the use of tactile sensing in robotics is that the sensors have to be spread along the robot body, the way the human skin is-thus dictating varied 3-D spatio-temporal requirements, decentralized and distributed control, and handling of multiple simultaneous tactile contacts. Satisfying these requirements pose challenges to making tactile sensor modality a reality. Overcoming these challenges requires dealing with issues such as sensors placement, electronic/mechanical hardware, methods to access and acquire signals, automatic calibration techniques, and algorithms to process and interpret sensing data in real time. We survey this field from a system perspective, recognizing the fact that the system performance tends to depend on how its various components are put together. It is hoped that the survey will be of use to practitioners designing tactile sensing hardware (whole-body or large-patch sensor coverage), and to researchers working on cognitive robotics involving tactile sensing.
15957432
A Large Area Tactile Sensor Patch Based on Commercial Force Sensors
This paper reports the design of a tactile sensor patch to cover large areas of robots and machines that interact with human beings. Many devices have been proposed to meet such a demand. These realizations are mostly custom-built or developed in the lab. The sensor of this paper is implemented with commercial force sensors. This has the benefit of a more foreseeable response of the sensor if its behavior is understood as the aggregation of readings from all the individual force sensors in the array. A few reported large area tactile sensors are also based on commercial sensors. However, the one in this paper is the first of this kind based on the use of polymeric commercial force sensing resistors (FSR) as unit elements of the array or tactels, which results in a robust sensor. The paper discusses design issues related to some necessary modifications of the force sensor, its assembly in an array, and the signal conditioning. The patch has 16 × 9 force sensors mounted on a flexible printed circuit board with a spatial resolution of 18.5 mm. The force range of a tactel is 6 N and its sensitivity is 0.6 V/N. The array is read at a rate of 78 frames per second. Finally, two simple application examples are also carried out with the sensor mounted on the forearm of a rescue robot that communicates with the sensor through a CAN bus.
10256708
Tactile sensing for an anthropomorphic robotic hand: Hardware and signal processing
In this paper, a tactile sensing system for an anthropomorphic robot hand is presented. The tactile sensing system is designed as a construction kit making it very versatile. The sensor data preprocessing is embedded into the hand's hardware structure and is fully integrated. The sensor system is able to gather tactile pressure profiles and to measure vibrations in the sensor's cover. Additionally to the introduction of the hardware, the signal processing and the classification of the acquired sensor data will be explained in detail. These algorithms make the tactile sensing system capable to detect contact points, to classify contact patterns and to detect slip conditions during object manipulation and grasping.
21510216
The design of attendant propelled wheelchairs
The attendant operated wheelchair is propelled by applying forces to handles at the rear of the chair. There are no published data to justify the design of pushing handles on existing wheelchairs. In Dundee, studies of pushing have been conducted in order to obtain subjective preferences for location and design of handles and an understanding of bio-mechanical factors associated with wheelchair pushing. Preferred positions for handles have been found to be in the region of 0.75 of shoulder height, 1.14 times shoulder width although deviations of +5% in these values are still rated as acceptable. The preferred positions do not correspond to minimum levels of resultant force or with lowest levels of moment in any of the upper body joints. Moments occurring at the lower back are not substantially affected by handle position. The biomechanical analysis so far has not revealed why some handle positions are more comfortable for pushing than others. Further study, involving calculation of resultant moments (rather than just sagittal plane moments) at these joints and at the lower body joints, is a next step in attempting to find the indicators of discomfort. Transferring a patient from or to a wheelchair can be a difficult operation with risks of accidents to the patient through falling and risks to the attendant of strain, particularly to the back. Current footrests on wheelchairs are a major source of the problems during transfer. A new approach to footrest design is described which solves these difficulties by using a footrest that lowers onto the floor. This has other attractive features such as providing good stability and restraint of the chair during transfer. The armrests are also discussed since they have a role to play where patients can assist themselves during transfer but have the potential for being an obstruction when patients need to be lifted from wheelchairs. The ease of pushing and manoeuvring, the difficulties caused by obstacles such as carpet edges and lift entrances, the operation of the brakes, and the position of the pushing handles are all important aspects of chairs used for transporting patients. The wheels, particularly the wheel diameter, tyre compressibility and castor trail, are determinants of the mobility aspects. However, the position of the wheels in relation to the centre of gravity and whether the castors are at the front or rear must also be considered. The brakes, as well as being effective, should be easy to apply and not too affected by wear. A prototype wheelchair is described which incorporates design features suggested by research into the above considerations.
121247505
Applied statistics for the behavioral sciences
This introductory text provides students with a conceptual understanding of basic statistical procedures, as well as the computational skills needed to complete them. The clear presentation, accessible language, and step-by-step instruction make it easy for students from a variety of social science disciplines to grasp the material. The scenarios presented in chapter exercises span the curriculum, from political science to marketing, so that students make a connection between their own area of interest and the study of statistics. Unique coverage focuses on concepts critical to understanding current statistical research such as power and sample size, multiple comparison tests, multiple regression, and analysis of covariance. Additional SPSS coverage throughout the text includes computer printouts and expanded discussion of their contents in interpreting the results of sample exercises. 1. Introduction. 2. Organizing and Graphing Data. 3. Describing Distributions: Individual Scores, Central Tendency, and Variation. 4. The Normal Distribution. 5. Correlation: A Measure of Relationship. 6. Linear Regression: Prediction. 7. Sampling, Probability, and Sampling Distributions. 8. Hypothesis Testing: One-Sample Case for the Mean. 9. Estimation: One-Sample Case for the Mean. 10. Hypothesis Testing: One-Sample Case for Other Statistics. 11. Hypothesis Testing: Two-Sample Case for the Mean. 12. Hypothesis Testing: Two-Sample Case for Other Statistics. 13. Determining Power and Sample Size. 14. Hypothesis Testing, K-Sample Case: Analysis of Variance, One-Way Classification. 15. Multiple-Comparison Procedures. 16. Analysis of Variance, Two-Way Classification. 17. Linear Regression: Estimation and Hypothesis Testing. 18. Multiple Linear Regression. 19. Analysis of Covariance. 20. Other Correlation Coefficients. 21. Chi-Square (X2) Tests for Frequencies. 22. Other Nonparametric Tests.
15252812
The Effect of Haptic Support Systems on Driver Performance: A Literature Survey
A large number of haptic driver support systems have been described in the scientific literature. However, there is little consensus regarding the design, evaluation methods, and effectiveness of these systems. This literature survey aimed to investigate: (1) what haptic systems (in terms of function, haptic signal, channel, and supported task) have been experimentally tested, (2) how these haptic systems have been evaluated, and (3) their reported effects on driver performance and behaviour. We reviewed empirical research in which participants had to drive a vehicle in a real or simulated environment, were able to control the heading and/or speed of the vehicle, and a haptic signal was provided to them. The results indicated that a clear distinction can be made between warning systems (using vibrations) and guidance systems (using continuous forces). Studies typically used reaction time measures for evaluating warning systems and vehicle-centred performance measures for evaluating guidance systems. In general, haptic warning systems reduced the reaction time of a driver compared to no warnings, although these systems may cause annoyance. Guidance systems generally improved the performance of drivers compared to non-aided driving, but these systems may suffer from after-effects. Longitudinal research is needed to investigate the transfer and retention of effects caused by haptic support systems.
12521277
Keeping In Touch Everyday (KITE) project: developing assistive technologies with people with dementia and their carers to promote independence
ABSTRACT Background: The role of technology to facilitate independent living for people with dementia is not fully realized, with initial attempts (e.g. tracking devices) being considered unacceptable from a practical and ethical perspective. The aim of this study is to create acceptable and effective prototype technologies to facilitate independence for people with dementia through a user-centered design process involving them and their carers. Method: The study comprised a three-stage participatory design process: scoping stage (five focus groups, 10 people with dementia and 11 carers); participatory design stage (five workshops, 22 participants) and prototype development stage (four meetings with two people with dementia and one carer). Focus groups and workshops were digitally recorded, fully transcribed and subjected to constant comparative analysis. Results: People with mild to moderate dementia enjoy a variety of activities both on their own and with their families; however, concerns included getting lost, a loss of confidence with curtailment of usual activities, and carer anxiety. Existing technologies (mobile phones) were used intermittently. Participants felt strongly that future devices should be disguised and be integrated easily into their daily routines. Suggested areas for functional improvement included two-way communications, flexibility of function as the illness progresses, and something to “guide” them home when out walking or driving. Attention should also be focused on minimizing the size, weight and visibility of devices to reduce stigmatization. Conclusion: Prototypes for two devices (armband and electronic notepad) were developed. The study showed that involving people with dementia in the process of participatory design is feasible and could lead to devices which are more acceptable and relevant to their needs.
16006576
Accessible contextual information for urban orientation
We present Talking Points, an urban orientation system based on the idea that an individual's walking journey can be enhanced by providing contextual information about points of interest (POIs) along their route. Our formative research revealed numerous ways to provide serendipitous and task-critical information for both sighted and visually impaired users as they navigate through an urban environment on foot. Based on this, we developed a prototype system comprised of the following: an unobtrusive mobile device to present the user with contextual information; a socially maintained online database containing information about POIs; software that is accessible via both a graphical and a speech user interface; and location "tags" to be detected by the unobtrusive device. This socially maintained urban orientation and contextual information system offers relevant, dynamic, and up-to-date information, a combination which may not otherwise be accessible.
129496831
Study of correlation between human height and foot length in residents of mumbai
A tall person needs long foot to support body and for increased balance. Foot size and height are both based on many factors such as gender, genetics, health and environment. Foot size may be used in forensic test to estimate the height of a person whose body is no longer intact. 
Aim To analyze the correlation between foot length and height in Mumbai Population. 
Methods The present study was done on 298 individuals residing in Mumbai. To find out the correlation between height and foot length, the subjects were divided into 6 groups according to the height and foot length & each subject was assessed. 
Results The average of mean foot length in males & females in all age groups from 11 years - 30 years (and more) is 20.80cm and 20.81 respectively .The correlation coefficient between height and length of foot also shows significant association for all the age group and sex. 
Conclusion Height of an individual either male/female is 6.5 times the length of his/her foot length
141030816
Hand Length as a Determinat of Height in School Children
The anthropometric characteristics of 600 normal Nigeria School Children of ages between 5-10 years of Gbagyi tribe of Abuja, with no obvious deformities or previous history of trauma to the hand were selected for this study. Of these children, males (n=300) with mean age of 7.10 ± 1.98, and females (n=300) with mean age of 7.68 ± 1.86) were investigated. The anthropometric characteristics of their height, age, weight, hand length, and body mass indices were measured, analysed statistically for any significant difference, and correlation between the parameters studied. The results show some significant differences between the anthropometric parameters and a significant correlation (≤ 0.001) between the height and hand length, and other parameters in both males and females. The study derived a linear regression and a multiple linear regression equations for Gbagyi School children of Nigeria from which height, age, weight, hand length and body mass index could be predicted if one factor is known. The results from the present study show that there was a positive correlation between height and hand length and other parameters indicating that height could be predicted using hand length, age, weight and body mass index among Gbagyi school children of Abuja-Nigeria.
384659
Hand length as an alternative measurement of height
Background/objectives:Despite the utmost importance of body height in evaluating nutritional status, it is not always possible to obtain its measurement and height may have to be estimated. The objective of the study was to formulate and cross-validate a regression equation to predict height using hand length measurement and also to determine if predicted height (PH) will lead to significant errors when used in body mass index (BMI) calculation.Subjects/methods:A cross-sectional study was conducted using a consecutive sample of 465 inpatients (19–91 years), from a university hospital. Participants were randomly divided into a development sample of 311 individuals and a cross-validation one. A linear regression model was used to formulate the equation. Intraclass correlation coefficients (ICCs) for single measures and differences between measured height (MH) and PH and between BMI calculated with MH (BMIMH) and with PH (BMIPH) were determined.Results:The regression equation for PH is: PH (cm)=80.400+5.122 × hand length (cm)—0.195 × age (years)+6.383 × gender (gender: women 0, men 1) (R=0.87, s.e. of the estimate=4.98 cm). MH and PH were strongly correlated, ICCs: 0.67-0.74 (P<0.001). Differences were small, mean difference±s.d., ⩽−0.6±4.4 cm (P⩾0.24). BMIMH and BMIPH were strongly correlated, ICCs: 0.94-0.96 (P<0.001). Differences were small, ⩽0.3±1.7 kg/m2 (P⩾0.10).Conclusions:The formulated regression equation using hand length, age and gender provides a valid estimation of height and is useful in the clinical context. PH from this regression equation can be used in BMI calculations as misclassification is small.