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• João Ferro

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I have read and understood the rules on cheating, plagiarism and appropriate referencing as outlined in the module assessment requirements guidelines document and I declare that the work contained in this assignment is my own, unless otherwise acknowledged. No substantial part of the work submitted here has also been submitted by me in other assessments for my degree course, and I acknowledge that if this has been done an appropriate reduction in the mark I might otherwise have received will be made.

Signed: ...................................................................... (please type name here)

MODULE TITLE:

System Modelling and Simulation WM053-15 01JL 15/16

COURSE DATE:

29th Feb – 4th March 2016

NAME: ........................................................... STUDENT ID: ………………………………….

POST MODULE ASSESSMENT System Modelling and Simulation 29th Feb – 4th March 2016 You are required to answer both Part A and Part B Part 1: Modelling, simulation and analysis of a vehicle quarter car suspension (20 Marks) The two system outputs are the displacements of the vehicle body and the wheel mass (z1 and z2). The input (z0) can be modelled as an impulse of magnitude 0.1m and duration of 1 second. Model parameter values:

M b  250 kg,

M w  20 kg,

K S  22 kN/m,

CS  1kNs/m,

K t  140 kN/m

Z0 Figure 1: Quarter car model (a)

Derive the 4 ODE’s that describe the dynamics of both the wheel mass and the vehicle sprung mass. Using the mathematical blocks provided within Simulink (integrators, gain, addition etc.), construct a simulation model of the quarter car shown in Figure 1. [8 marks]

(b)

Using the Simulink state-space block, verify the model constructed in (a) against the matrix form of the system model given above. [3 marks]

(c)

What are the body and the wheel natural frequencies for the vehicle? [2 marks]

(d)

Amend the model in (a) replacing the damping term Cs with a non-linear suspension damper that generates a different bounce and rebound force defined by Table 1. The damping force generated saturates at a relative velocity +/-1.5ms-1. How does the vehicle response differ? Relative velocity (ms-1) Damping Force (N)

-1.5

0

1.5

-2900

0

1200

Table 1 Non-linear damper characteristic [3 marks]

(e)

Export the data from Simulink into MATLAB as a “Structure with Time” and write an M-file that plots the response of both the linear and non-linear systems on a single graph. Ensure the figure is properly annotated – to include: different line-types/colours, legend, axis labels etc. [4 marks]

Part 2: Critically Review the 1-D Modelling strategy employed within JLR relating to the complete life-cycle of the model development process (definition, creation, validation, model use). Using academic literature to support your argument, suggest ways in which the organisation may improve. This part of the assessment should be completed within 1000 - 1200 words, it is suggested that you focus on one stage or facet of the complete life-cycle. Example topics may include, but are not constrained too:  The justification employed for creating models and how models are shared / archived within the company  How models are created and shared within the JLR supply chain  How models are validated and verified before their use  How the 1-D modelling strategy is aligned with the broader virtual design strategy employed within the company  How models are employed within the broader product development process  How models are designed using multiple simulation platforms and tools Irrespective of which topic is chosen it is important that you clearly define: (1) current practice within the company; (2) the perceived problem or shortcoming that can be improved; (3) best-practice derived from the literature and finally (4) how JLR may adopt these improvements. Note: You are expected to provide evidence to support the recommendations that you make. These must come from academic sources, e.g. Conference or Journal papers (e.g. SAE, IEEE, IMEchE etc.). You should aim for at least 10-15 references that are properly cited using recognised methods, e.g. the Harvard style. [20 Marks]

Part 3: Systems Modelling and Simulation within Jaguar Land Rover (30 Marks) Choose a system or vehicle function from a current or legacy vehicle programme in your functional area or within the broader organisation. Using the approaches taught during the module develop a model of the chosen system. It is important that you select a problem that is of sufficient complexity that you can demonstrate your attainment of the Intended Learning Outcomes. You are expected to use a systematic approach to model development, working through: Part (a) (c)

(d)

(e)

(f)

(g)

Assignment Area Marks Provide justification for the need to produce a model, including the 2 identification of use case (s) for the model and modelling tools employed. Define the model requirements, including: 3  Model structure (i.e. linear vs. non-linear)  Model components (i.e. required frequency range)  The physical laws and their interconnection  The data requirements both for model parameterisation and validation Construct simulation model(s) with the chosen modelling tool(s): Simulation diagrams and 10 model code should be included in the assignment Annex and marks will be allocated for structure and clarity. Verify the simulation model(s) in terms of correct implementation in the 5 chosen modelling tool (i.e. steady-state analysis using fundamental physical laws). Validate the simulation model (if possible) in terms of how representative it is of reality. If validation is not possible clearly identify the main areas of uncertainty and define a validation strategy highlighting key areas, i.e. the inclusion of additional tests to verify a subset of the model behaviour. With reference back to the model requirements and justification (Part a), carry out simulation experiments which must include a series of “what if” to clearly demonstrate the use and value of the model Demonstrate the application of JLR standards to the derivation and simulation of the model.

5

5

Access to Matlab, Dymola and possibly other tools are available through JLR network licenses. If you are unsure as to what constitutes a suitable project for Parts 2 or 3 please contact the Module Tutor (James Marco) and/or the JLR Module Champion (James Chapman) who will be able to direct you to key individuals within JLR that may be able to provide real-world problems for you to base your assignment on. Intended Learning Outcomes – Mapping module intended learning outcomes to module assignment Module ILO Model Definition Model Creation Model Implementation Model Verification / Validation Model Application

1a X X

1b

1c

1d X X

1e

X X X

2 X X X X X

3a X

3b

3c

X

X

3d

3e

3f

X

3g X X X

X X

COMPLETION DATE – Your assignment is to be submitted electronically to Nicola Kirkwood ([email protected]) (as one document only) not later than 5pm Monday 23rd May 2016

Please Note Your attention is particularly drawn to items 2 and 3 below regarding the need to submit assignments on time. 1. Academic Guidelines The module you are attending is accredited towards an academic award. As a consequence the module is operated within defined academic guidelines and the assignment following the module must comply with requirements covering breadth and depth and be submitted within a specific time scale. 2. PMA Lateness Penalties Post Module Assignment (PMA) that does not reach WMG by the due date will be considered to be late. Academic penalties for lateness will be applied at the rate of 3% per working day after the due date. Penalties are applied up to a maximum of 14 days after which time the work will be recorded as a non-submission. Late scripts are still assessed and, subject to achieving an acceptable mark, will enable the module to be counted as an attendance credit to the award for which the participant is registered. 3. PMA Submission timing For the purposes of clarity:  For submission dates which fall on Monday – Thursday, PMA must be received by WMG no later than 17.00.  For submission dates which fall on a Friday, PMA must be received no later than 16.00 PMA received after these times will be stamped and recorded as having arrived on the next working day. It is the participant’s responsibility to get the PMA to WMG by the required deadline. The post office delay mail which carries insufficient postage. You are advised to get proof of postage. 4. Extensions to PMA Submission Date The University requires that all participants registered for an award should, wherever possible, be treated equally being neither advantaged nor disadvantaged compared to others. Thus, if you believe that you are disadvantaged compared to others, it is possible to apply for an extension to the PMA submission date. Holidays and workload are not normally accepted as justification for an extension. Extended work assignments away from base, illness and bereavement of a close family member would normally be considered as justifying a reschedule of PMA submission dates. In such situations contact Nicola Kirkwood at [email protected] as soon as you are able to. Retrospective extensions are not normally granted. Supporting information from a Line Manager or a Doctor may be requested.