Design, Modelling and Analysing of a Vehicle Drivetrain using SimDriveline, and Model based design of a simple power transmission system

 

Faculty of Computing, Engineering and Media

Course work Specification 2019/20

Module name:

Electromechanics

Module code:

ENGT5101

Title of the Assignment:

Design, Modelling and Analysing of a Vehicle Drivetrain using SimDriveline, and Model based design of a simple power transmission system

This coursework item is: (delete as appropriate)

Summative

Formative

This summative coursework will be marked anonymously

Yes

No

The learning outcomes that are assessed by this coursework are:

1. Ability to be familiar with the basic building blocks of the SimDriveline model, including their characteristics and purposes

2. Ability to model different power transmission systems (e.g. gear and clutch systems) and vehicle drivetrain using SimDriveline

3. Ability to analyse the system behaviour by defining input signals using signal builder and plotting of output signals with the use of scopes where appropriate

4. Ability to perform model based design with a simple case study (simple power transmission system)

5. Ability to describe and discuss the main features of model based design methodology.

This coursework is: (delete as appropriate)

Individual

Group

If other or a mixed ... explain here:

This coursework constitutes 30% to the overall module mark.

Date Set:

1 November 2019

Date & Time Due:

23:59 Friday 20 December 2019

The ‘normal’ coursework return date for this work is:

By 27 Jan 2019

When completed you are required to submit your coursework to:

submit via Turnitin only, its link will be provided on BlackBoard a week before the deadline.

Late submission of coursework policy: Late submissions will be processed in accordance with current University regulations which state:

“the time period during which a student may submit a piece of work late without authorisation and have the work capped at 40% if passed is 14 calendar days. Work submitted unauthorised more than 14 calendar days after the original submission date will receive a mark of 0%. These regulations apply to a student’s first attempt at coursework. Work submitted late without authorisation which constitutes reassessment of a previously failed piece of coursework will always receive a mark of 0%.”

Academic Offences and Bad Academic Practices:

These include plagiarism, cheating, collusion, copying work and reuse of your own work, poor referencing or the passing off of somebody else's ideas as your own. If you are in any doubt about

2

what constitutes an academic offence or bad academic practice you must check with your tutor. Further information is available at:

http://www.dmu.ac.uk/dmu-students/the-student-gateway/academic-support-office/academic-offences.aspx and

http://www.dmu.ac.uk/dmu-students/the-student-gateway/academic-support-office/bad-academic-practice.aspx

Do not contract out your work externally or sourcing your work externally! You may not outsmart your tutor by deceiving. It is an extremely risky business. Plagiarise twice and you could be expelled from the university.

Tasks to be undertaken: See coursework attachment

Deliverables to be submitted for assessment: See coursework attachment

Preparation of report – please read carefully: Please download this form and enter your answers into boxes only.

No more than 30 pages for the main content. Spread your effort uniformly. Extra pages will not be marked. Analysis is crucial for this report, not just figures and results. All figures included must be described briefly. Keep answer brief and meaningful. Please adhere to the 5C principle – clear, concise, complete, technically correct, and critical analysis. More could be worst than less if random meaningless writing is included. Use the Point, Evidence, Explanation method (PEE) to guide your writing.

How the work will be marked:

The report will be marked (primarily 60%) based on the correctness and logical manner of the results obtained from the models; and (the other 40%) based on the comments, explanations, verifications and analysis presented. Keep your answer clear, concise, complete, technically correct, with reference to the theories learnt.

Results & Calculations (60%)

Analysis

(40%)

Part 1 (20%)

Part 2 (20%)

Part 3 (20%)

Part 4 (20%)

Part 5 (20%)

Discussion 70%

Calculations (30%)

Total 100%

Module leader/tutor name: Meisam Abdi – Q3.05h T: 0116 250 6447 E: meisam.abdi@dmu.ac.uk

Contact details:

3

De Montfort University

ENGT5101 Electromechanics

2019/2020

Design, Modelling and Analysing of a Vehicle Drivetrain using SimDriveline, and Model based design of a simple power transmission system

Please note that the models shown were based on SimDriveline R2017a available from the University’s lab – the newer versions of the software should be able to achieve the right results About SimDriveline

( http://uk.mathworks.com/products/simdrive/)

Introduction

You have studied various components of machine system such as belt drives, clutch and gear systems but lack experience in design, modelling and analysis of this kind of system, for example, a Vehicle Drivetrain. This coursework is designed in such a way that you will first be familiar with simple system by exploring and analysing available examples, then moving on to define input into the system to investigate the output or the behaviour of the system. In addition, you will be required to model a Vehicle Drivetrain based on a well-recognised system, and analyse the system behaviour with the aim to redesign or modify the system to meet different operational requirements.

If you need to be familiar with Matlab / Simulink environment, please visit: http://uk.mathworks.com/products/simulink/index.html [1]

Learning Objectives

1) To be familiar with the basic building blocks of the SimDriveline model, including their characteristics and purposes

Model and simulate rotational and translational mechanical systems

Simscape Driveline™ (formerly SimDriveline™) provides component libraries for modeling and simulating rotational and translational mechanical systems. It includes models of worm gears, lead screws, and vehicle components such as engines, tires, transmissions, and torque converters. You can use these components to model the transmission of mechanical power in helicopter drivetrains, industrial machinery, automotive powertrains, and other applications. You can integrate electrical, hydraulic, pneumatic, and other physical systems into your model using components from the Simscape™ family of products.

Simscape Driveline helps you develop control systems and test system-level performance. You can create custom component models with the MATLAB® based Simscape language, which enables text-based authoring of physical modeling components, domains, and libraries. You can parameterize your models using MATLAB variables and expressions, and design control systems for your physical system in Simulink®. To deploy your models to other simulation environments, including hardware-in-the-loop (HIL) systems, Simscape Driveline supports C-code generation.

4

2) To learn how to model different power transmission systems (e.g. gear and clutch systems) and vehicle drivetrain using SimDriveline

3) To learn how to analyse the system behaviour by defining input signals using signal builder and plotting of output signals with the use of scopes where appropriate

4) To be able to perform model based design with a simple case study (simple power transmission system)

5) To be able to describe and discuss the main features of model based design methodology.

Procedures:

1. Analysis of Simple and Variable Gear Systems (20%)

Start the Matlab/Simulink application, locate the file by clicking Help – Examples – Simscape Driveline – browse for Simple Gear – click Open Model. Save another version of the file to a suitable directory with other suitable filename to avoid changes to the original sample files.

Figure 1. Simple Gear Model

a) With the use of Help – Documentation (F1) – Search Help (by keying the keywords), briefly introduce the purpose of the Solver, Mechanical Rotational Reference, Simulink-PS Converter (and the corresponding PS to Simulink Converter), Inertia and Scope. Also explain the differences between PS and Simulink signals and how they are represented in the SimDriveline blocks.

b) Double click on both the sensor blocks, list the type of sensors used in this model and briefly introduce their functions.

c) Plot the output signals on the scope.

d) Introduce one of the meshing losses to the gear and plot the output signals on the scope, comment on the difference between the output signals

5

e) Now locate the file related to Variable Ration Gear (figure 2) by clicking Help – Examples – Simscape Driveline – browse for Variable Ratio Gear – click Open Model, again rename the file.

Figure 2. Variable Gear Model

f) Briefly explain the Variable Ratio Transmission block and the B, F and r ports on the block.

g) Explain the purpose of the Signal Builder; plot the input signal from the Signal Builder and the output signals on the scope.

h) Then add an additional signal to the Signal Builder, alter the signal connection to the new signal, and plot the relevant system input signal and system output behaviour. Give your comment where appropriate.

i) Briefly discuss your observation of the results/plots obtained and draw necessary conclusions.

For use by tutor only:

Results (60%)

Analysis

(40%)

Comment:

Part 1

Total

(100%)

6

2. Analysis of Simple Hydraulic Clutch System (20%)

Locate the file by clicking Help – Examples – Simscape Driveline – browse for Hydraulically-Actuated Driveline Clutch – click Open Model, again rename the file.

.

Figure 3. Hydraulically-Actuated Driveline Clutch Model

a) Explain the operation of the hydraulic clutch system.

b) Briefly introduce the components within the Hydraulic System and Hydraulic Clutch.

c) Plot and explain the input signal from the Signal Builders and the output signals on the scope.

d) Modify the input signals of the throttle and pressure to simulate other driving behaviour.

Plot the relevant system input signal and system output behaviour.

e) Comment on the differences on the output signals.

f) Briefly discuss your observation of the results/plots obtained and draw necessary conclusions.

For use by tutor only:

Results (60%)

Analysis

(40%)

Comment:

Part 2

7

Total

(100%)

3. Modelling and Analysis of a Vehicle Drivetrain (20%)

In this part of the work, you are required to create a vehicle drivetrain model as shown in Figure 4 using SimDriveline, which can also be used for controls development.

Figure 4. Vehicle Drivetrain [2, 3]

a) You can access the blocks through the Simulink Library Browser. Open the browser by clicking the Simulink button. In the contents tree, expand the Simscape entry, then the SimDriveline subentry.

b) You could do this by referring to the demo from http://www.mathworks.co.uk/videos/modeling-a-vehicle-powertrain-68822.html

c) The completed model should look similar to Figure 5.

Figure 5. SimDriveline Model of a Vehicle Drivetrain

Tyre

Differential

Simple Gear

Engine

Torque Convertor

8

d) Attach the model developed below. Explain the purposes of the torque convertor and the differential.

e) Plot the engine power and vehicle speed.

f) Now modify the system to investigate the behaviour of different parts.

• Replace the simple gear with a variable gear (variable ration transmission), set the gear changes with a signal builder and a Simulink-PS Converter (e.g. in the variable gear model). Plot the relevant system input signal and system output behaviour.

• Instead of driven by Constant Physical Signal (Open Throttle), simulate a driving behaviour where the driver increases power gradually, remain constant for a short interval and reducing at the same rate of increasing the power (similar to the Throttle signal in the Hydraulic Clutch model) . Plot the relevant system input signal and system output behaviour.

g) Briefly discuss your observation of the results/plots obtained and draw necessary conclusions.

For use by tutor only:

Results (60%)

Analysis

(40%)

Comment:

Part 3

Total

(100%)

9

4. Model based design of a simple power transmission system (20%)

You have been assigned to design a suitable power transmission system consisting of a motor with gearbox to drive a screw thread of 20mm in nominal diameter with a pitch of 3mm, as shown in Figure 6, in order to lift a mass of 40kg at a constant speed of 250mm/min; the coeffcicient of friction of the screw thead is 0.25:

Figure 6. A power transmission system for lifting (illustration only)

i) With the use of model based design in Simulink, create a Simulink model of the system. Include the suitable sensor(s) to monitor the speed of the motor and the load in the model. Show your model below:

ii) Design, by calculation, a suitable gear ratio for the gearbox, such that the maximum motor speed should be about 25rev/s. Then suggest a suitable motor torque based on the torque for lifting the load. Show the calculations below:

If the motor should achieve the final lifting velocity from 0 to 25rev/s in 2sec, workout the suitable torque for acceleration, by taking into considerations the total moment of inertia involded as 0.004kgm2. Show your calculations below:

iii) Suggest a suitable final torque required by the motor.

With reference to the Modelling a Mechatronic System on https://uk.mathworks.com/videos/modeling-a-mechatronic-system-68829.html http://www.mathworks.co.uk/videos/modeling-a-dc-motor-68852.html

create a more complete model integrating a customised version of the DC motor (with Voltage Source, PWM, H-Bridge and the relevant sensors) according to your design requirements, and simulate the behaviour of the system. Show your model below:

iv) Include the simulation results/plot and discuss the results accordingly, draw relevant conclusions.

10

For use by tutor only:

The model (60%)

Analysis

(40%)

Comment:

Part 4

Total

(100%)

5. Additional Discussions (20%)

a) Briefly discuss the trade-offs between accuracy and speed in terms of the driveline simulation performance.

b) Briefly discuss the limitations of the SimDriveline software (SimDriveline Help).

c) Briefly summarise the type of components that can be modelled in SimDriveline.

d) Briefly discuss how you can create Custom Components [4] if the components required are not available in the library by referring to the Simscape Language Guide.

e) Briefly discuss further procedures on Performing Hardware-in-the-Loop (HIL) Simulations and Deploying Drivetrain Models after the model has been built, simulated and analysed [4].

f) Include brief conclusions (summary of findings) in your report.

For use by tutor only:

Discussions (70%)

Conclusions

(30%)

Comment:

Part 5

Total

(100%)

Plagiarism Concern

Similarity Score:

Comment:

11

References:

1) Simulink - Simulation and Model-Based Design http://uk.mathworks.com/products/simulink/index.html

2) SimDriveline – Demo and Webminar

http://www.mathworks.co.uk/products/simdrive/webinars.html

http://www.mathworks.co.uk/help/physmod/sdl/index.html

3) Vehicle Powertrain Simulation with Simscape Driveline

https://uk.mathworks.com/videos/vehicle-powertrain-simulation-with-simscape-driveline-119545.html

4) SimDriveline - Model and simulate one-dimensional mechanical systems

http://www.mathworks.co.uk/products/simdrive/

http://www.mathworks.co.uk/videos/simscape-language-mechanical-example-68868.html

Other interesting models:

1) Modeling a Ratchet Mechanism with Leadscrew

http://www.mathworks.co.uk/videos/modeling-a-ratchet-mechanism-with-leadscrew-68824.html

2) Planetary Gear With Losses

http://www.mathworks.co.uk/videos/modeling-losses-in-a-planetary-gear-68819.html

3) Modeling a DC Motor

http://www.mathworks.co.uk/videos/modeling-a-dc-motor-68852.html

http://www.mathworks.co.uk/videos/pid-controller-design-for-a-dc-motor-68881.html

4) Simscape Language: Mechanical Example

http://www.mathworks.co.uk/videos/simscape-language-mechanical-example-68868.html

5) Simscape Language: Electronic Example

http://www.mathworks.co.uk/videos/simscape-language-electronic-example-73114.html