Department of Electrical Engineering and Electronics

ELEC120/ELEC123 –ELECTROMECHANICS AND MECHATRONICS

DESIGN ASSIGNMENT 2022-23 INSTRUCTIONS

Instructions:

For this design assignment you will be assuming the role of an engineer for the City Council. You have been asked to produce a poster which details and evaluates current traffic detection methods, and recommends improvements which could be made (specifically in induction loop systems) to enhance the experience of bicycle users.

You should complete the Design Assignment Template with your own text where indicated and submit this document for assessment. (You can alter the template to best suit your poster design, the template is just a guide)

The deadline is midnight Tuesday 25^th April. Submit electronically via Canvas -> ELEC120 or ELEC123 -> Assignments -> Design Assignment. Late submissions will be penalised according to the standard University Policy.

In the poster you should include and consider:

Brief overview of different types of detection systems, benefits of using induction loop based systems

How induction loops work to detect traffic

Construction materials used in bicycles that can be detected by the induction loop (hint: what about carbon fibre bicycles?)

Analyses of the designs given in table one (details given below) and any additional shapes you recommend (provide reasoning for any shapes you choose).

Provide an analysis (for example graphs and explanation) of the differences between circular loops and rectangular loops, using the equation for inductance stated below and the values given in tables 2 and 3 (see below). Not all the values required are included and these will require research to determine, please state any of these values (assumptions) you use and why you have chosen them.

State which shape you recommend and why.

Provide a brief overview of where else induction loops can be used.

A list of references (at least 5, but probably more)! Remember to reference any sources throughout the poster where appropriate.

Table 1:

You have to sketch the magnetic field lines for a section of induction loop shapes (drawn on computer or by hand are both acceptable) and a square loop is completed as an example. You are also asked to think about the magnetic field intensity in the third column – useful to identify any null spots where a bicycle would not be identified.

Table 1: Different induction loop shapes and their magnetic field properties

Table 2 and Table 3:

Using the Equation for an inductor, calculate the inductance of each loop when no vehicle is present using the specifications given in the table.

L = Inductance, H

µ₀ = Permeability of free space, Hm^-1

µ_r = Relative permeability

N = Number of turns

A = Cross-sectional area, m²

l = length of loop, m

You will need to think about what suitable values for each of these terms is.

I do not expect you to calculate each value manually! Use a MATLAB and make the computer do the hard work for you.

Table 2: Calculated inductance for a rectangular induction loop

Table 3: Calculated inductance for a circular induction loop

References:

As this assignment contains research I would expect there to be at least 5 references in a report. Use IEEE standard reference format

Do not reference Wikipedia – I will subtract marks if you do this because it not necessarily a reliable source of information. You can look at Wikipedia, but use it to find links to other sources which will contain more information and then reference these.

Useful links for reading:

US Federal Highway Administration, “Traffic Detector Handbook” Third Edition, Volume I

http://www.fhwa.dot.gov/publications/research/operations/its/06108/index.cfm

Bicycling Education and Advocacy in North Carolina, “How to Turn Signals Green”

http://humantransport.org/ncbikeed/?page_id=37

Steven G. Goodridge, “Detection of Bicycles by Quadrupole Loops at Demand-Actuated Traffic Signals”

http://humantransport.org/ncbikeed/?page_id=44

KM March 2023