Year Submitted: 2018
University: University of Sheffield
List of Team Members (with year of graduation): Courtney Algar (2018)
Faculty Advisers: Tony Dodd
Main Contact Email Address: firstname.lastname@example.org
Title: Walking at 20mph: A solution to the urban mobility crisis
Development of a novel solution to inner-city transportation aiming to produce a concept device that is a clean, portable and healthy form of personal transportation.
NI Virtual Bench
Across the world cities are experiencing hugely damaging effects from our current transportation habits. As populations rise and more people move into dense urban areas, congestion levels increase, producing large amounts of pollution. This costs the world economy billions of pounds annually and produces profound effects on people’s health.
Electrification and automation are bound to dramatically change the situation surrounding air pollution in cities and improve levels of urban congestion. However, they also encourage users to be inactive and therefore still fail to create clean, portable and healthy transport.
The project took the idea of walking, a physically active yet non-straining method of personal transport and attempted to address the two main issues preventing people from walking more as a mode of transport; speed and range.
With the aim of making a person capable of walking at 20mph a number of vital sub-systems were produced:
Drive: A custom drive mechanism was developed from the ground up. This consisted of a series of six Polyurethane wheels each housing individual Li-ion batteries and routing current through the bearing to minimise the device footprint. This supply was used to power the front two wheels via a belt drive and BLDC motor.
Mechanical: Each component of the aluminium structural system, was CNC machined forming a stable platform. This enabled a user to walk without limiting their range of movements but whilst maintaining a rigid connection between motor and wheels.
Sensor: Aluminium loadcells were designed to elastically deform under the load of a user. Three loadcells under each foot have sufficient resolution to acquire an accurate, real-time dataset of force measurements under my feet as I walked. This was achieved by the use of strain gauges running through a Wheatstone bridge/ amplifier circuit and using the DAQ capabilities of the NI myRIO as a standalone device.
Computational: The computational system then used LabVIEW to implement a simple rule-based algorithm. This system, read the loadcell data and when specific conditions where met would run a predefined PWM sequence.
Combining each of these separate systems, I created a device that could be walked in comfortably, would measure the force under three strategic points of your foot and relate these force measurements to the users walking cycle. The LabVIEW application would subsequently power the wheels under a user’s toes as they push off allowing them to walk as normal except now at 20mph.
Why I chose NI:
The NI platform proved vital in the success of this project allowing me to develop technologies much faster and more flexibly than other systems could offer. Using NI Virtual Bench extensively throughout the development enabled me to take a portable workstation to any lab around the University (or even at home) and troubleshoot my device at any location necessary, immediately allowing me to troubleshoot the source of any issue. This was essential in allowing me to be able to prototype custom electronics in a short timeframe.
Whilst under a lot of time pressure with this project the MyRIO running LabVIEW also offered an out of the box solution to acquiring data, visualising that data and understanding the changes necessary to be made. This speed in developing the computational and sensing sub-systems is the only reason I could complete this project in the given timeframe.