Understanding the inner-workings of city-level agent-based models

Lead Research Organisation: University of Leeds
Department Name: Sch of Geography

Abstract

Agent-based modelling (ABM) is rapidly becoming established as a standard tool for the social
scientist. Its ability to represent individuals, their unique characteristics and behaviour provide
a template for allowing simulations of human behaviour to be created. Typically, the
application systems that ABMs are used to replicate, for example cities, are heavily imbued
with complexity and non-linear dynamics. However, we lack the tools to understand the
interplay of these dynamics and the part they play in the final model output. This is particularly
important if we are to create robust models that can be used within the policy arena. This is
also timely; the growth in new forms of individual micro-data (big data) will only increase the
potential for ABM to give new insights into how individuals use and interact with systems.
Using the outputs for several scenarios such as health or retail related, from a city level
ABM, this PhD will evaluate and apply a range of techniques from Machine Learning (ML)
for uncovering the inner-workings of ABM. This will give insight into which processes the
model is, and is not replicating well. Specifically, the aims will be:
1 Critical evaluation of different techniques from ML - which offers the greatest
potential for understanding the interplay of ABM rules? This will include both
methods for visualisation of the system as well as statistical appraisal.
2 Adaption of these approaches for application to ABM outputs
3 Application of ML approaches to ABM outputs and critical evaluation.
The outputs of this PhD will be the application of one or more ML inspired approaches that
will shed light on the black box nature of ABM.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
ES/P000401/1 01/10/2017 30/09/2024
2106407 Studentship ES/P000401/1 01/10/2018 30/04/2023 Sedar Olmez
 
Title 3D Urban Traffic Simulator (ABM) in Unity (version 1.0.0) 
Description The Urban Traffic Simulator is an agent-based model developed in the Unity platform. The model allows the user to simulate a number of autonomous vehicles (AVs) with the ability to tune granular parameters such as vehicle downforce, adherence to speed limits, top speed in mph and mass. The model allows researchers to tune these parameters, run the simulator for a given time period and export data from the model for analysis. The Urban Traffic Simulator was developed in Unity 2019.3.03. The core model only requires Unity version 2019.3.03+ and the source code in the Assets folder to deploy. 
Type Of Material Computer model/algorithm 
Year Produced 2021 
Provided To Others? Yes  
Impact We experimented with the model and the results will be described in a paper we wrote titled: "Exploring the impact of driver adherence to speed limits and the interdependence of roadside collisions in an urban environment: an agent-based modelling approach." This paper will provide researchers with a blueprint for future publications that can be written using this agent-based model. Currently, the first draft is complete and not yet sent to a peer-reviewed journal. 
URL https://www.comses.net/codebases/32e7be8c-b05c-46b2-9b5f-73c4d273ca59/releases/1.0.0/
 
Title Drive Cycle Data from the 3D Urban Traffic Simulator (ABM) in Unity (version 1.1.0) 
Description This repository contains datasets from the 3D Urban Traffic Simulator ABM: Each vehicle type, PHEV and ICEV were simulated across nine different speed limit adherence and density scenarios. The output data columns are: AgentID: the unique agent identifier. xAxisPos: the x-axis position of the agent. zAxisPos: the y-axis position of the agent. collisions: the total number of times a vehicle has collided with another. topSpeed(mph): the top speed the vehicle is set to achieve throughout its drive cycle. currentSpeed(mph): the current speed of the vehicle in mph. distanceOfTravel(meters): the distance the vehicle has travelled over its drive cycle. raycastLength: the length at which the vehicle can identify objects, 1 - very short to 10 high vision distance. tractionControl: traction control initiated; some vehicles will have traction control, others will not; this is entirely arbitrary. VelocityMagnitude(BETA): the magnitude of the velocity for the vehicle. VehicleMass: the vehicle weight in kg. Downforce: the force applied to the vehicle to create more grip, 0.1 - small force to 10.0 - more force. date-time: date and timestamps for each data point collected, currently its milliseconds and multiple actions by the raw physics engine can occur throughout the simulation. Therefore, large amounts of data points are collected for each run in a short space of time. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
Impact These datasets were utilised in an upcoming article on quantifying energy consumption in cities using electric vehicles. Anyone who works with drive cycle behaviour and EV research may utilise our datasets from the Urban Traffic Simulator. 
URL https://figshare.com/articles/dataset/Drive_Cycle_Data_from_the_3D_Urban_Traffic_Simulator_ABM_in_Un...
 
Title Energy Calculation Extension for the article: An Agent-Based Simulation of Heterogeneous Driver Behaviour and its Impact on Electric Energy Consumption in Urban Space. 
Description The Energy Calculation Extension is a jupyter notebook that quantifies the energy expenditure for the outputs of simulation runs from the Urban Traffic Simulation (ABM) published here: Sedar Olmez, Obi Thompson Sargoni, Alison Heppenstall, Daniel Birks, Annabel Whipp, Ed Manley (2021, March 22). "3D Urban Traffic Simulator (ABM) in Unity" (Version 1.1.0). CoMSES Computational Model Library. Retrieved from: https://www.comses.net/codebases/32e7be8c-b05c-46b2-9b5f-73c4d273ca59/releases/1.1.0/ The notebook takes as input, outputs from the aforementioned model and produces statistical analysis and quantifies the energy used by electric motored vehicles. The complete datasets used in the journal article: An Agent-Based Simulation of Heterogeneous Driver Behaviour and its Impact on Electric Energy Consumption in Urban Space. Can be found at the following source: @article{Olmez2021, author = "Sedar Olmez and Alison Heppenstall", title = "{Drive Cycle Data from the 3D Urban Traffic Simulator (ABM) in Unity (version 1.1.0)}", year = "2021", month = "11", url = "https://figshare.com/articles/dataset/Drive_Cycle_Data_from_the_3D_Urban_Traffic_Simulator_ABM_in_Unity_version_1_1_0_/17099858", doi = "10.6084/m9.figshare.17099858.v1" } This repository contains a reproduced lite version of the code, to run all the experiments, you need to download all PHEV and ICEV csv datasets from the above link. 
Type Of Material Data analysis technique 
Year Produced 2022 
Provided To Others? Yes  
Impact The interactive notebook allows users to run the Urban Traffic Simulator, produce some drive cycle data from the model then input that data into the Energy Calculation Extension which will quantify the energy demand from the fleet of vehicles. This model should allow people to: - quantify energy demand in cities. - analyse the dynamics of energy demand from driver behaviour and complex space. - make forecasts on how much energy may be required to charge vehicles in future cities with electric vehicles. 
URL https://codeocean.com/capsule/9598578/tree/v1