Our Team's Electrical & Computer Engineering Problem-Solving Effort

Smart Walking Stick

Objective:

Cities and towns leave much to be desired in terms of accessibility for those who are visually impaired. These individuals often have to rely on someone else or a service animal to get to where they need to go, but there are many situations where these resources are not available to them. To resolve this, the goal is to engineer a smart walking stick that can communicate any hazards that the user would not be able to notice on their own. This device would grant its user the independence most people take for granted.

Background: 

• This smart walking stick is for those who are visually impaired and need assistance navigating their daily environments. It is also useful for those who require the use of a walking aid such as a cane. 

• The types of environments this device is expected to be used in include 

  • Indoor environments such as homes, stores, and other public buildings

  • Outdoor environments such as sidewalks and parks

  • Urban environments with many people and cars

Methodology:

The walking stick will be able to analyze the user's immediate surroundings using ultrasonic sensors and cameras to notify the user when an obstacle or object may impede their path, such as with curbs, ditches, moving vehicles, etc. The stick will communicate with the user through audio and haptic feedback.

Expected Results:

The new features introduced with the walking stick will create a significantly improved user experience compared to non-smart models. We expect injuries of users to decrease drastically as a result of the improved safety features. This will also drastically increase the ability of visually impaired people to go out and do daily activities, as they do not need to go out at a specific time frame and will not require an assistant to accompany them. 

Costs:

Component costs:

• Walking Stick [$30 - 50]

  • For a mid-range, good quality walking stick and good lifespan

• Ultrasonic Sensor [$5]

• Camera Module [$26]

  • Compatible with Arduino

• Microphone Module [$4 for 3]

• Buzzer & Potentiometer [$3]

• Vibration / Haptic Feedback Motor [$1]

• Microcontroller [$54]

  • While the selection may change in the future, an Arduino UNO Wi-Fi REV2 may be a good choice for this project as it has Wi-Fi and Bluetooth® capabilities that will provide flexibility for the team in designing a product.

• Buffer [$20]

  • For shipping costs, other parts that were not accounted for in first estimation, etc.

Based on this preliminary cost breakdown, a prototype may cost around $143, which is not ideal. However, with further research into which sensors the walking stick actually needs, as well as how the team may achieve a balance of functionality, quality, and affordability, it is likely the price will decrease. Also, buying components in bulk or using individual components more effectively may drive the price down as well.

Smart Walking Stick Solution Development

Design each task in a problem-solving effort so that it is most fruitful and provides the most information or guidance. 

Design Tasks:

1. Highlight the possible hazards found in sidewalks or near regular traffic that pose a threat to visually impaired/elderly people to find solutions that can be implemented in the product

2. Learn about the wants and needs of visually impaired and elderly pedestrians to create an experience to base the product design on

3. Study the designs of existing walking sticks and canes to see what can be improved or included

4. Examine the structure of collapsible walking devices to enhance convenience for daily usage

5. Research hardware such as speakers, sensors, and microcontrollers to engineer a reliable product

6. Perform iterative field tests to calibrate product sensitivity modes for expected surroundings (crowded areas with foot and road traffic, sidewalks with ditches or steep curb drops, etc.)

7. Create an accessible walking stick that enables a worry-free walking experience for visually impaired/elderly people

Use various attributes of the final solution state to guide earlier decisions made along the solution path 

1. Speed

2. Performance

3. Cost

4. Reliability

5. Ergonomics

Define design goals and design specifications

General Design Goals:

• Safety

• Reliability

• Performance

• Ease of Operation

• Durability

• Minimum Cost

• Minimum Maintenance & East of Maintenance

Specific Design Goals:

• The team shall create a mechanism that allows for two functions of the Smart Walking Stick, one as a more traditional cane, and the other as a walking stick. Ideally, this mechanism is sturdy enough to withstand all of the forces it will be subjected to. 

• Optimize for very high power efficiency in order to achieve a long battery life.

• The team shall also design a system for audio and haptic feedback that alerts the user about changes in terrain.

Design Constraints:

• The biggest design constraint is speed and performance, as this will allow us to reach our general goal of safety. Quick processing of the environment will allow the user to act on any threats to their safety.

• The Smart Walking Stick shall be affordable to reach and help as many people as possible

• Reliability is a top priority. The Smart Walking Stick shall work seamlessly daily.

• Achieving an ergonomic, comfortable experience is likely the most challenging constraint. The device shall be lightweight despite having many electrical components and improved structural performance.

Design Specifications:

Electronics:

• LiDAR sensor to measure distance of potential obstacles

• Stereo camera to measure distance and view objects

• Microcontroller to control devices 

• Speakers for interfacing with user

• Tek 002 haptic feedback device

Hardware:

• Raspberry Pi 4 Model B to be able to handle all required processes

• Rechargeable Lithium Battery 

Software:

• OpenCV for image processing (version 4.7.0)

Structural Materials:

• Strong frame with enough flex to not break on touching hard surfaces

Eliminate paths that do not satisfy the desired goals and/or specifications

1. Sole reliance on haptic feedback technology, as haptic feedback is not robust enough to deliver all required information

2. Non-repairable system, as replacing individual components will likely not be feasible in the long term

Smart Walking Stick Intellectual Properties

Trademarks (or service marks)

1. WeWALK [link]

• WeWALK sells a "Smart Cane" that enhances a cane's typical feedback from interacting with the ground using ultrasound. It features an app that can communicate with the cane and the company also offers training for customers. 

2. Advanta Health Solutions, LLC [link]

• This company sells software and has trademarked the phrase "SmartWalking"

Copyrights (or licenses)

1. WeWALK [link]

• WeWALK copyrighted their product (mentioned above) and their website.

2. Torchit [link]

• Torchit copyrighted their website and product, "Saarthi," which converts a regular walking stick into a smart walking stick with adaptable obstacle detection and an ergonomic design.

Patents (or standards)

1. Intelligent Walking Stick [link]

• Expired patent for an intelligent walking stick comprised of an elongated frame with a handle, power source, transmitter, receiver, processor, warning device, and identifying information in the processor on the person carrying the walking stick.

2. Location, orientation, product and color identification system for the blind or visually impaired [link]

• Active patent where the tip of a white cane for the blind houses a barcode reader, sonar, color sensory, and audio production mechanisms to form an apparatus capable of audio or vibratory output when detecting obstacles, drop-offs, or informational barcode sites. 

3. Intelligent Walking stick with automated alarming function in case of falling [link]

• Active patent for a walking stick featuring an alarm function incase of the user falling which uses acceleration sensors, GPS systems, and a communication module for mobile communication. Automatically sends information to contacts incase a fall is detected.

4. Intelligent Guiding System for Obstacle Avoidance [link]

• Active patent for a system which utilizes an intelligent walking stick, voice interaction earphones, and a mobile capable monitoring application to help guide the user. 

5. Intelligent blind guiding stick based on image identification [link]

• Active patent on walking stick using Bluetooth headset, road condition recognition subsystem, and blink tracker.

6. Intelligent internet of things blind-guiding stick [link]

• Active patent on walking stick utilizing radar, GPS, Bluetooth audio and vibration module.

Security Breach / Hacking

Someone with malicious intent may hack into the Smart Walking Stick and disable the onboard sensors and cameras that interpret the user’s environment into actionable feedback. They could also change the feedback to mislead the user, or even lead them into a more dangerous situation.

Solution

We will include user configurable firewalls in order to allow users to determine their own levels of security. We will also include an option to factory reset the Smart Walking Stick to return it to its original state in the event it does get hacked. The firewall will allow the users to enable two-factor authentication as well as a password to unlock the device.

Overreliance

A user may become so reliant on the feedback from the Smart Walking Stick that they ignore their natural instincts and awareness, becoming more susceptible to dangerous scenarios in their environment.

Solution

We will include reminders to the user to stay aware whenever the Smart Walking Stick is turned on. The reminder will be an audio clip that instructs the user to remain aware of their surroundings.

Unnecessary Use

People who do not need the Smart Walking Stick, are not visually impaired, and do not need assistance walking on their own may misuse the product for entertainment purposes or to use their phone or other distraction as they walk. This would make them susceptible to accidents or other harm as they are not adequately paying attention to their environment. A large demand for the walking stick may also take supply away from those who need it. 

Solution

We will require users to submit verification in order to purchase the Smart Walking Stick and prevent users who may not need the device from purchasing it. The verification will be an eyeglass prescription given by a doctor that proves a user is visually impaired. 

Worn Equipment Failure

Since the walking stick makes frequent contact with the ground, the tip is susceptible to wearing out. This leads to a possibility of the tip slipping from the ground, making the user trip.

Solution

We will offer replacement tips at regular intervals to avoid having the user rely on worn down equipment. Routine quality assurance will be implemented so that these replacements will not be so frequent and inconvenience the user. 

Length Hazard

In some cases where the walking stick is long enough to do so, or when the user’s arm is a certain length, the device may hit the ankles/feet of surrounding pedestrians. This may cause others to fall and injure themselves. 

Solution

We will include a feature in the design where the length of the walking stick is adjustable so the user may change it as needed. The device will include an optional feature where a looped sound can play to alert surrounding pedestrians of the user’s presence. 

Stomach Jabbing Hazard

The typical tip shape of the walking stick is vulnerable to getting stuck in the cracks of sidewalks that users frequent while in use. The tip getting stuck may cause the device to suddenly jab the user in the stomach, which causes pain and discomfort. 

Solution 

Instead of a regular tip, the design will utilize a roller ball that easily avoids getting stuck into sidewalk cracks. It will be manufactured with a lightweight, durable material, stainless steel. 

Potential Issues with Disposal of the Device After End of Life (EOL)

The following components of the device present an environmental risk of producing microplastics after disposal:

• Arduino UNO Wi-Fi REV2

• Plastic Enclosure of System

• Misc. parts in Sensor, Camera, Microphone, Motor

Solution

Many components of Arduino are recyclable even if single components fail. To prevent the production of microplastics, the plastic enclosure of the Smart Walking Stick will be designed with a biodegradable material. At the EOL, any user can return the device to manufacturers, where components will be taken apart. Remaining parts will be recycled and reused.

Smart Walking Stick Senior Design Plan

Stage 1: Problem Formulation

• Determine whether to pursue the same topic or pivot to a new direction

• Conduct market research and hold customer interviews, revisit Needs Assessment

• Get in contact with industry professionals for their insight

• Develop the constraints for the project, research material properties, decide where to source materials

Stage 2: Development

• Establish a system and process diagram that encapsulates the proof of concept

• Review possible scenarios for the device and perform solution development

• Conduct feasibility studies with potential clients 

• 3D model initial body of device in SolidWorks (save electronic components for prototyping)

Stage 3: Prototyping

• Create initial prototype with key features determined from customer research.

• Test prototype thoroughly to ensure the design requirements are met

• Based on test results, refine prototype until it is satisfactory

• Iterate on old designs by repeating the building and testing processes until the final product is achieved.

Stage 4: Liability Proofing

• Waivers for user testers in order to mitigate liability

• Create documentation for proper use of the device and it’s features for user testers

• Analyze current design iteration for possible safety risks and weak points

• Work on risk mitigation strategies for risks involved with improper product use and possible failure points

Stage 5: Implementation and Presentation

• Create final iterations based on user feedback and testing results

• Benchmark project metrics and functionality

• Evaluate budget and potential material and market restrictions

• Analyze risk of project based on cost and market research data

• Meet with stakeholders and finalize stakeholder demands 

• Design final pitch video and project presentation

• Present design at Design Expo