Dhruv Jain, Prabhav Agrawal, Kartik Maheshwari, Aman Mittal, Akshay Gupta, Amaury Ollagnier, Arpit Goyal, Rohan Paul, Ashish Ranjan, Anuraag Gupta, Manas Paldhe, Prof. M. Balakrishnan, Prof. P.V.M. Rao Indian Institute of Technology, New Delhi, India and Supriya Das, Saurabh Sanyal, Yogesh Taneja, Mr. Dipendra Manocha Saksham Trust, New Delhi, India ‘ROSHNI’ FOR THE VISUALLY IMPAIRED: Design and user study of an affordable indoor navigation system
Introduction to the problem Measures adopted by visually challenged for indoor navigation Importance of an indoor navigation system Aim of the project Features System description User interface Installations and user study System installations in a university building Experimentation Conclusion Comparison with existing systems Future plan Overview
Measures adopted by the visually challenged for navigating in unknown indoor environments BehaviourProblems Arrange for a sighted person to accompany for the trip. Creates dependence. Lowers self-esteem. Find a sighted person like guard in the building and ask for help. Very unreliable. Person may unintentionally give confused directions. Ask strangers in the building frequently for directions until the destination is reached Very unreliable. There may not be enough people in the building. Try to find signs by hit and trial approach Very unreliable. There may not be sufficient cues in the building.
1.Independent Mobility: Primary Challenge for the visually impaired 2.Difficulty in navigation especially in GPS denied environment 3.Low cost solution required 4.Current systems have limitations: Unaffordable cost Non availability of sales, marketing or servicing in developing countries Highly inaccurate and thus unsuitable for public use Cumbersome to carry or difficult to operate. Importance of an Indoor Navigation System “ Presently, there is no system available in developing countries that allows a blind person to navigate freely in an indoor environment ”
Aims of this Project To design and implement an affordable user-enabled system for convenient indoor navigation. To assist the user in reaching the desired destination of the building through active acoustic messages. The system operation must be controlled entirely by the user with no dependence on sighted assistance, require minimal modifications and should be easily retrofitted to existing building infrastructure. To install the system on multiple floors of a university building and conduct experiments with potential users under normal conditions and collect user feedback.
System Description Use of infrared sensor and inertial unit to identify the position. Providing auditory output emanating from the mobile phone application storing the map of the building. Buzzer to beep on reaching the destination. Mobile application Location from IR unit Location from inertial unit Voice output to the user WALL MOUNTED WAIST WORN
User Interface Mobile application Present user module Users navigating with Roshni
System Installation on an institute building Track used for user trials. Red dots represent position of infrared units, yellow arrows shows the traversed path (left) University building where the system was installed (right).
Experimentation Setup Infrared unit mounted at every 5-7 m on the walls and doors of all possible destinations on the path User module was attached to the waist and mobile phone was given to be kept in hand/pocket and tested with 6 users Standardized protocol 1.Training phase First day: introduced to the modules Second day: operation of the mobile application, reinforcement sessions on a simpler track 2.Trial phase Baseline questionnaire Field testing Post-trail questionnaire User navigating without any external sighted assistance. User module (red arrow) and wall-mounted module (black-arrow)
Results 1. Questionnaire based survey Users mentioned that most buildings rarely have accessible signage. Random exploration: find signs, ask for help, hit and trial approach. Emphasized their high degree of anxiety, hesitation to ask for help. Reported frequently getting lost and injured. 2. System effectiveness All users were able to learn the operation and were able to use the system as an effective navigational guide. Significant reduction in (i) Time of travel (ii) Deviation from direct path for users unfamiliar with the building. Ineffective for frequent visitors. Experimentation Reporting user feedback
Histograms illustrating the effectiveness of Indoor Navigation System (INS) in reducing Time of Travel (left), Deviation from Direct Path (right) (Without System (blue) and With System (Red)) Results 3. Post-experiment User Feedback All 6 users believed it is useful for a day to day living and will be willing to use the device as a future product. Mentioned that they were able to reach their destination comfortably. Suggested significant improvement in design: Multi-lingual supportReduction in size Clearer accent Provision to mount on walking cane Experimentation
Comparison with Existing Systems DeviceConceptLimitationsBenefits of Roshni Talking Signs Network of infrared transmitters installed on the walls (or poles) at strategic locations. The user must point a directional IR beam towards the transmitter Large number of transmitter units have to be installed adding to a high setup cost User doesn’t need to point leading to successful navigation Only required to be installed at a distance of 5-7 m or at destinations Building Navigator Building is fitted with retro-reflective bar- coded signs Handheld device transmits the beam which is reflected and decoded by computer software User has to carry a bag pack which is heavy and inconvenient User carries a relatively small waist worn unit
DeviceConceptLimitationsBenefits of Roshni PERCEPT RFID embedded in kiosks located at specific points like entrance, elevators etc. Information communicated to the mobile on touching the tags via glove. Doesn’t convey the position of the user in between sparsely placed kiosks Location of kiosks has to be known beforehand Position conveyed to the user at all times using IR/ inertial unit Building is entirely transparent to the user. Only the map has to be stored in the mobile phone. Cricket Sensors Ultrasound modules mounted on ceiling at regular intervals Use of Sonar technology to identify the position Although very efficient, it is very highly priced Affordable to a moderate user in a developing country Comparison with Existing Systems
Plan 3 phase approach Phase 1: Concept demonstration Lab prototype demonstration showing the basic feasibility of the device. Phase 2: Pilot stage development Full deployment of the system in an institute building for regular trials. Phase3: Industrial Production Pairing up with a company for large scale production of devices. Currently in Phase2: Pilot stage development. Looking for funding partners for further research towards product realization Currently in Phase2: Pilot stage development. Looking for funding partners for further research towards product realization
IMPLICATIONS Affordable system. Affordable system. Can be integrated into the existing Can be integrated into the existing infrastructure. infrastructure. Facilitates independent indoor navigation in an unfamiliar environment. Facilitates independent indoor navigation in an unfamiliar environment. Small, easy and convenient for individuals with low vision. Small, easy and convenient for individuals with low vision.
References Talking Signs Inc. 2000. Talking Signs Locations in San Francisco. [Online] http://www.ski.org/Rehab/WCrandall/introts.html [June 2007]. Beckmann Pj, Giudice NA, Legge GE, Roy R, Tjan BS. 2005. “Digital sign system for indoor wayfinding for the visually impaired”, Proc 1st IEEE Workshop on Computer Vision Applications for the Visually Impaired, in conjunction with CVPR 2005, San Diego, 2005. Gandhi Siddhesh Rajan, Ganz Aura, Mullett Gary, Puleo Elaine, Schafer James, Singh Tushar, Wilson Carole. 2011. "PERCEPT: Indoor navigation for the blind and visually impaired", Engineering in Medicine and Biology Society, EMBC, 2011 Annual International Conference of the IE  Kalia A.A., Legge G.E., Ogale A., Roy R. 2010. Assessment of indoor routefinding technology for people who are visually impaired”, Journal of Visual Impairment & Blindness, 104, 3, 135-147. Barlow Janet M., Bentzen Billie Louse, Franck Lukas. "Environmental Accessibility for Students with Vision Loss" in Blasch B.B., Weiner W.R., Welsh R. L., Eds. 2010. “Foundations of Orientation and Mobility”, 3rd ed., New York: American Foundation for the Blind. Note: All pictures are used with the permission of the users.
Comparison with Existing Systems DeviceConceptLimitationsBenefits of Roshni Devices using gyroscopic, compasses and sensors Use of compasses and gyroscopes and sensors to determine and position and orientation of the user. Less accurate Affected by changes in environmental temperature, magnetic fields Expensive Considerable accuracy Not affected by environmental changes Affordable Devices using RF/Wifi or other wireless technology Use of signal strength of wall mounted RF/Wifi to localise the user Signal strength in such systems is subjected to change due to obstacles, environmental conditions and thus is inaccurate Doesn’t use signal strength so is immune to such defects.