TAEHYUN LIM, ETHAN BISWURM
KEYWORDS. Visually Impaired, Smart Technology, Walking Stick, Harmonious Haptic Technology, and SrVi.
ABSTRACT.
Out of the 285 million people who are visually impaired worldwide, a majority of them are burdened with relying on archaic walking sticks and guidance dogs. Although countless smart solutions are offered for users without disabilities, there is a certain lack of user-friendly technology for people who are visually impaired. With the help of Harmonious Haptic Technology, use of vibrations, a traditional walking stick can be transformed into a fully functioning smart technology for the visually impaired. Smart Vision (SrVi), provides a cost-effective and practical solution for the target group. The modes available on SrVi offer the opportunity to aid the visually impaired to successfully embark on public transportations and move through various obstacles with more ease.
INTRODUCTION.
According to the World Health Organization (WHO), 285 million people are estimated to be visually impaired worldwide. Specifically, 39 million are blind and 246 million have low vision. Among the 285 million, 90% are living in developing countries and 82% of people living with blindness are aged 50 and above [1]. It is known that humans receive information from the environment through the following five senses: 1% by taste, 1.5% by tactile sense, 3.5% by smell, 11% by sound and 83% by sight [2]. As these statistics show, eyesight is the key method used by humans to process information. Thus, people who are visually impaired have a great disadvantage in processing information in their daily lives.
Additionally, research shows that vision loss is correlated to an increased risk of unintended injuries [3]. People who are visually impaired are most often unable to navigate through space without bumping into obstacles when they are without any assistance. More specifically, the target users could experience surroundings consisting of tall furniture, which cannot be easily detected with a simple walking stick. Furthermore, the target users could face difficulty, even harm, while riding public transportations [4].
Currently, there are several methods that are made available to the visually impaired in order to aid them in navigating through the course of their daily lives. The traditional walking sticks are the commonly preferred option; nonetheless, they are not completely accurate in terms of detecting the user’s surrounding and providing precise locations of danger. Another solution is the use of guidance dogs. However, it takes over one full year to train guidance dogs. Due to the fact that dogs’ life spans last about 10 to 13 years, dogs cannot provide a long-term solution to the target group. Furthermore, the high cost (including maintenance fees) of guidance dogs is also another reason why people who are visually impaired prefer using walking sticks. Although it is true that there are other products on the market that provide noteworthy services, such services are offered at a high cost, making it an impractical option to the majority of the target group who are living in developing countries.
There has been and continues to be a rise of smart solutions incorporated within the field of technology. The development of smart technology focuses heavily on electronics that are user friendly, comfortable and “smart”; indeed, technology strives for usability—providing ease to the daily tasks of its users. However, technology has yet to take into consideration the use of electronic devices for disabled users, specifically in the case of those who are visually impaired. As previously stated, the risk of having an unintentional injury is higher for people who are visually impaired compared to those with full sight [5]. These risks are further exacerbated in certain groups such as seniors [6].
One of the most significant smart solutions that could benefit people who are visually impaired is the development of Harmonious Haptic Technology. The use of Harmonious Interface Communication (HIC) Technology is the use of vibrations to communicate an object’s location by giving tactile feedback to the users. In fact, this use of vibrations is a well-known method of alarming and alerting user’s attention. By incorporating HIC technology to an already existing product that visually impaired people use (a traditional walking stick), a user-friendly product could offer even more opportunities to its users.
The benefits of using smart technology include allowing the visually impaired to understand their surroundings through previously immeasurable aspects. Through the use of HIC technology the users would not only be able to understand what obstacles lie at a distance, but also at what distance each obstacle is from themselves and be able to respond to them in a quicker manner. Another benefit of this type of technology is that tools utilizing HIC can be expanded to be mass produced on an assembly line. This aspect could also be seen as a disadvantage as the software would require development and testing. Users that are less adept at understanding smart technology may also find this solution less intuitive and be unable to utilize it effectively. However, with the development of modern manufacturing, the technology necessary for HIC – small motors and control boards – have become easily affordable to consumers.
MATERIALS AND METHODS.
Consideration of a cost-effective walking stick was one of the critical factors while bearing the materials in mind for this project. Furthermore, the design of the solution heavily focuses on the usability and practicality of the digitized walking stick.
Considering the Materials.
A variety of materials were taken into consideration. A particular consideration was taken into account in terms of its practicality and cost-effectiveness. Furthermore, as the ultimate goal is to aid the visually impaired in sensing their environment, materials must be lightweight. Therefore, the design product should consist of aluminum alloy in order to provide the user with a lightweight, rustproof, and even retractable walking stick. In addition, the sonar sensors should be covered with rubber, while the infrared (IR) sensor should be coated in resin to keep the product waterproof. Finally, the grip should be made out of rubber with a tessellating surface texture to maximize traction. The aforementioned characteristics of a smart walking stick would allow for the user to experience a durable, convenient and cost-friendly device.
Designing the Base Shaft.
The basic design of the suggested product will be similar to that of an existing walking stick: 1 meter while fully extended, 25 cm while retracted, and with a diameter of 1.8 cm. The base is constructed to be retractable using several aluminum rods that have different diameters to allow for them to collapse into one another.
With the design and material specifications of the base, the developers of Team Spark commissioned the base to be customarily constructed by a metalworker. After a week, the base had been completed with a net weight of 1.3 kg.
It is also important to note that the reason for the similarities of the basic frame to that of the traditional walking stick is to allow the users to easily adapt to the smart walking stick.
Finding Low Cost Materials.
In order to provide a cost-efficient solution for the visually impaired, the price was taken into consideration. E-commerce websites such as Alibaba.com were used to research the lowest prices possible, in addition to handcrafting necessary materials when possible.
The final price for all the components totaled at $4.71. However, if this product were to have been mass-produced, there would be additional fees for taxes, shipping, handling, and manufacturing. Taxes are a significant factor to take into consideration as the cost of raw materials may be low but due to the production tax, the actual cost of production can be considerably high. In addition, if SrVi was to be internationally distributed, the shipping fee becomes a factor that would directly lead to an increase in price. This means that the price has to be standardized considering the tax rates of each country. The result of such mass production would raise the initial price to roughly $25.94 (Refer to Table 1 below).
In addition to cutting out the middleman, the developers of Team Spark handcrafted some of the materials. With 3D printing and laser cutting, the developers were able to create the following materials: casing, switches, and waterproofing material. Finally, it is important to note that in comparison with other products with similar features priced at about $300, SrVi seems a plausible gadget to buy.
Table 1. Projected Total Cost of a Single SrVi
Adding the Sensors, the Microcontroller Unit, and the Vibration Motors.
The construction of the prototype began with the base shaft of SrVi. Then the microcontroller was attached to the very top of the basic mold using a combination of hot glue and screws. The necessary wires were then sorted and added. Then, a two-piece 3D printed casing was mounted over the microcontroller to cover it and keep it secure.
Afterwards, the switches for the modes are attached and cased in close to the handle. The wires attached to the sensors were then grouped together outside the casing and strung through a plastic tube to prevent tangling. Subsequently, the sonar sensors were attached to the bottom tip of the base shaft, facing upwards at a 45° angle to the ground.
Then, the IR sensor and a ball caster were added to the bottom of the base shaft. The IR sensor is used to sense the color of the surface that SrVi is rolling on across any surface, regardless of its direction. Finally, at the handle of the base, small vibration motors were attached, which respond accordingly to the input of the modes (Refer to Figure 2.).
Table 2. An Overview of Algorithms of Default Mode, Mode 1 and Mode 2.
SrVi is programmed to operate in two separate modes depending on the situation. Mode 1 of SrVi is used to both recognize objects and detect the yellow tactile paving on the roads below SrVi. Objects detected by the sonar sensor are then indicated by the buzzer, which will beep at a pace that is relative to the distance of the object from the user. The infrared sensors at the bottom of SrVi will detect whether or not the surface below the product is yellow, warning the user about the advisory boundaries. What the IR sensors detect is then conveyed through the vibration motors.
Mode 2 is set to only recognize obstacles in the way of the user in a discreet way. Through the utilization of the sonar sensors, the vibrating motors will indicate detection of an object through different levels of vibration, which are dependent on its proximity to the user.
Figure 1. Flow Diagram of Obstacle and Line Detection Algorithm
This flow diagram (shown in Figure 1) represents the programming processes for SrVi. First, it is important to note that when the power for SrVi is turned on, SrVi is in default mode and the angle sensor assigns a numerical value to the current angle of the stick. If the value is between 30° and 60° to the ground, then SrVi can proceed onto the other two modes. The process of detecting the angle is repeated if the range is outside of 30° to 60°. However, if the angles are at 0° or 90° SrVi will automatically power off to conserve energy and extend battery life. This process considers the fact that most users hold walking sticks at a roughly 45°.
Mode 1 is used to both recognize objects and detect yellow tactile paving on the roads below SrVi. The line detection checks if there is a yellow surface beneath the sensor and triggers vibration motors, while continuing to check if there are more yellow surfaces below. Even if no yellow surface is detected, the detector will continuously check for the color yellow. On the roads and streets, the color yellow is identified as an indication of caution and it is rare to find other objects that are similar to those of caution blocks or yellow strip of line. Yellow objects are not enough to be detected by the IR sensor that is placed on the very bottom of SrVi.
The sonar sensors are used for obstacle detection. They continuously send out sonic waves to detect any objects in their vicinity. If an object is detected, the sensors will be triggered. Depending on the modes, the buzzer (Mode 1) or the vibrator (Mode 2) will set off. In other words, while on Mode 1, the walking stick will beep when an obstacle is detected and vibrate when a yellow surface is detected. The modes are geared towards using the buzzer less, in order to allow the users and the people around them to experience minimum extraneous noise. Therefore, Mode 2 can be considered as a more discreet mode, which does not offer line detection, but offers obstacle detection, and triggers vibrations.
DISCUSSION / RESULTS.
Figure 2. Final Prototype of SrVi
SrVi (shown in Figure 2) offers an innovative solution to the target users. SrVi is a combination of an intuitive design and cost-efficient solution. Priced at less than $30 (shown in Table 2), SrVi provides its users with modes that recognize objects and lines, which will help people who are visually impaired to navigate through obstacles. This low pricing will not only allow the 46% of the US workforce that are visually impaired at a consumer level, but also those in developing countries to purchase the product with some government-provided financial aid.
SrVi’s two main functions are its Obstacle and Line Modes. The Obstacle Detection Mode focuses on accurately detecting objects that are beside or in front of the user. The vibrations on the stick can occur on the left or right side, corresponding to the object’s location in relation to the user. The side of the vibrations also provides varying strengths of vibrations to provide the user with information on the proximity of the object.
The Line Detection Mode detects the yellow tactile paving on pathways. This mode can enable the users to navigate through streets conveniently and safely arrive at their destinations. The vibrator will set off when the IR sensors cannot detect a yellow line, warning the user of the potential dangers at hand.
The three available modes (Default Mode, Mode 1 & Mode 2) can enable the target users to be more protected from unintentional injuries and otherwise unnoticed moving obstacles.
CONCLUSION.
People who are visually impaired are subject to unintended injuries among other challenges, such as difficulty in navigating through houses, streets and public transportations. 82% of people living with blindness aged 50 and above are calling for a cost-efficient solution. Current solutions that are available include guidance dogs and walking sticks. With the use of Harmonious Haptic Technology, use of Harmonious Interface Communication (HIC), vibrations can be used to communicate the location of objects by giving tactile feedback to the users.
This design-based research aims to build a working prototype of the solution to the problem the target users face. In fact, Team Spark has already completed a working prototype, which was successfully demonstrated at the 2016 Robofest World Championships, bringing home first place. Before the prototype was fully tested with those who are visually impaired, volunteers were recruited to test the product. Out of the 20 volunteers, the success rate was over 87%. It was a clear indication that the prototype was ready for improvements.
While developing our prototype for SrVi, there were several limitations that challenged the investigation process. One of these limitations is that there was no rigorous development and testing of multiple prototypes. The programming of the product also did not follow strict coding practices and may run less efficiently than is possible. Moreover, due to the limited number of visually impaired volunteers, the prototype could not be tested with a larger sample size.
The intentions for SrVi are heavily set on finding cost-friendly materials. Some of the major materials that make up the product are the infrared sensor (IR), angle sensor, sonar sensor, contractible aluminum stick and vibration motor. These materials are essential for the use of SrVi’s three modes, which allow the user to experience additional advantages to a traditional walking stick. The default mode is supported with an angle sensor that detects what angle the stick is at. If the stick is at 0° or 90° it will automatically turn off. Mode 1 utilizes vibration motor, sonar sensor and IR sensor to detect yellow lines and detect moving objects. Mode 2 utilizes the vibration motor and sonar sensor to recognize obstacles in the way of the user, to allow the user to navigate in a discreet manner.
The various modes of SrVi—including Mode 1 and 2, which can be manually changed—can allow the users to alleviate some of the difficulties they may face with the currently available options.
The walking stick should be tested over a longer period of time to make sure that it is error-proof in order to ensure that it will perform over an extended period of time to the users. This would increase the validity and the viability of this research for aiding the visually impaired. Furthermore, with extensive research and feedback from users, perhaps more modes could be explored as an option for the future.
ACKNOWLEDGMENTS.
I would like to give special thanks to Sang Hun Oh, our mentor and team coach, for his guidance and support. I would also like to acknowledge Team Spark, specifically John Baik and Jay Lee, for their contributions to the development of SrVi.
REFERENCES
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< http://www.who.int/mediacentre/factsheets/fs282/en/ >.
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