This assignment assesses students with the content from Week 1 to Week 5. You will be given 14 questions. You must provide detailed solutions to the problems given in the assignment in order to demonstrate your knowledge and understanding of the concepts and processes incorporating relevant sketches, clear step-by-step solutions and conclusion/judgement on answers.

- Correctly identify the problem to be solved (key terms, units, elements, or parts of a problem)

- Choose the most appropriate approach to solving the problem

- Clearly present the solutions with sketches (if necessary) for the problems

- Attempt logical alternative approaches to solving the problem

- The following should be considered when entering your answer.

• You will be given problems with different marks shown next to each problem number.
• You have unlimited attempts. However, each attempt allows 10 tries after which you will need to start a new attempt. A new attempt will generate a new set of numbers in the problems.
• You can navigate through the problems using 'QUIZ NAVIGATION' on the left.
• Numerical answers must be entered to 3 significant figures, and there is no harm in entering answers to 4 or 5 significant figures. An answer of 0.1467 has 4 significant figures; if you enter such an answer as "0.15", it will be marked incorrect. Always keep at least 3 or 4 decimal places during your working.
• The default sign convention for rotation is that anticlockwise is positive. If you are asked to enter an angle as an answer, this is the convention that the computer will be using.
• Unit for acceleration: m/s^2
• Unit for angles: deg or rad
• When you type your answer, remember 3 things: sign (+ or -), numbers, and units!

Task 1: Design (or find) a 1 (or 2) DOF walking mechanism that is reasonably simple but still functional. You will need to assume the working condition of the walking mechanism, such as its walking speed, motor speed, and weight and materials of each link and the main body. This task will need to be completed concurrently with Task 2.

Task 2: Demonstrate the kinematic and kinetic analysis of the design of your choice. This task will need to be completed concurrently with Task 1.

You are required to assess your peers' interim reports as well as your own according to the following marking guidelines and are expected to provide sincere feedback and accurate marks for your peers. This is a valuable chance for reflection after viewing other submissions. 67% of this assessment will be from the marks from your peers and the rest will be from the quality of your feedback to your peers.

• Presentation (/20)
  • Does the report overall give you a good impression?
  • Does the quality of the presentation give you confidence in the quality of the content?
  • What is the overall quality of English expression? Is technical jargon correctly used? Is the language clear and concise?
  • Is the report correctly sectioned? Do the sections flow correctly and aid the overall argument?
  • Are figures presented in a clear way that maximises the communication of information?
  • Is the referencing consistent and easy to follow?
  • Does the abstract/executive cover all aspects of the report while maintaining its conciseness?
  • Overall, is the contained information efficiently communicated to the reader?

• Context and aims (/20)
  • What background information has been provided to justify that the project is meaningful/achievable?
  • Do you, as a reader, understand the context of the problem and how solving it makes a valuable contribution to knowledge?

• Design of a mechanism and kinematic diagram (/20)
  • A kinematic diagram that clearly describes the mechanism
  • Its design meets the requirement specified in the assignment document.
  • Reasonable assumptions for its dimensions and materials; therefore, the mass of each link and the entire system is justified.

• Kinematic analysis and verification process (/20)
  • Good position, velocity and acceleration analysis with relevant diagrams
  • The relationship between the input motor speed and operation speed has been defined.
  • Presentation of Autodesk Inventor model
  • Hand calculations have been verified with Dynamic Simulation in Autodesk Inventor

• Discussions and conclusions (/10)
  • Correct interpretations and descriptions of the design and results
  • A good summary of the report and clear statements of meeting aims and objectives defined in the introductory part.
  • Identification of items to improve in the final report

• Progress (/10)
  • Completion of Task 1 with all required deliverables
  • Completion of Task 2 with all required deliverables

You, as an engineer, are requested by Queensland Police to design a shock absorber system for the Segway patroller.

Task 1: Design of a shock absorber system - Find the necessary stiffness and damping constant of the shock absorber system when the damped period of vibration is (to be given) seconds to meet the requirement of Queensland police specified below.

Design requirement

-          The current Segway patroller weighs 55 kg. The total weight of the new suspension system and its rider is expected to be (to be given) kg.

-          The new suspension system is expected to reduce the vibration amplitude to (to be given) in (to be given) cycles when the Segway patroller is subjected to an initial vertical displacement due to a road bump.

Task 2: Demonstrate the performance of your design – The new Segway patroller with your suspension system is to be tested on a rough road whose surface varies sinusoidally with an amplitude of Y = 0.05 m and a wavelength of 3 m.  If the Segway patroller travels at (to be given) km/h, what is the displacement amplitude of the new Segway patroller with the suspension system from Task 1.

• Presentation (/25%)
  • The report is in a professional and consistent format.
  • The report meets the proposed specification (file format, length, etc.)
  • Good quality of English expression is demonstrated, and its language is clear and concise.
  • The report is sectioned properly to aid the overall argument.
  • All figures and tables are labelled properly and discussed in the text.
  • Figures and tables are relevant and informative.
  • Correct citation and reference styles are used in accordance with the suggested referencing system.
  • Good use of visual aids is demonstrated.
• Introduction and background (/15%)
  • A clear statement about why the report was commissioned in the first place.
  • Comprehensive, detailed and focused context about the presented work is given.
  • Succinctly lead the reader to the purpose of the work being documented.
  • The objectives of the work are expressed well.
  • Previous reports and research, if the present report builds on, are included.
• Methods and results (/25%)
  • Detailed information on the approach and/or materials used in the study
  • Sufficient references are provided to support the methodology used in the report.
  • Results are presented in a logical way.
  • Clear but concise evidence in the form of statistics, graphs and tables
  • Justification for conclusions and recommendations
• Discussion (/20%)
  • Analysis using your own words on the method and results
  • Good interpretation and explanation of the results
  • Relation of the results with the literature
  • Examine whether and how the questions raised in the introduction have been answered.
• Conclusions (/15%)
  • Clear agreement with all the objectives that were set out in the introduction is made.
  • The significant findings and elements from the report are highlighted.
  • The main points of the report are drawn.
  • A clear statement about how the topic relates to its context (an evaluation of the importance of the topic, implication and/or recommendation for future studies)

You are going to conduct three labs, namely Free vibration, Forced vibration, and Mass balance. After conducting these labs, you will complete each task given in the lab worksheet template. You don't need to give lengthy answers for the discussion tasks. You must show all workings where applicable. You must cite the sources of your argument and discussions as per the referencing style specified in the unit profile. This lab worksheet must NOT exceed 15 pages. You will submit it to the submission link provided in Moodle.

- Accurate results 

- Accurate plots with correct axis titles and legends

- Appropriate discussions with supporting references

Your final report will include Tasks 1 and 2 with further improvement from your interim report.

Task 3: Conduct vibration analysis of your design

• Isolate the walking mechanism including its body with a housing and motor from its surrounding
• Assume its motor is placed right in the middle of the housing on top of a beam as below. You will need to assume the length, width, thickness and material of the beam, based on the size of your mechanism.
• Determine the global mass centre of your design and demonstrate an analytical approach to determine the forced amplitude of the motor under the operating condition defined earlier. (Hint: You will first need to calculate the flexural stiffness and spring constant of the system, thereby defining the natural frequency and frequency ratio)
• Suggest how the forced amplitude can be minimised and prove your solutions

Task 4: Verification of your analysis and Evaluation of your design

• Replicate your design in Autodesk Inventor
• Verify your analysis in Task 2 using Dynamic Simulation in Autodesk Inventor
• Verify your analysis in Task 3 using Dynamic Simulation in Autodesk Inventor

The following criteria will be used to grade your report. This is not the suggested structure of your report.

• Innovation and creativity (/20%)
  • The demonstrated mechanism is designed by oneself or an effort is made to improve the current design.
  • How complex or simple the chosen design is.
  • How accurate the chosen mechanism is interpreted.
• Presentation (/20%)
  • The report is in a professional and consistent format.
  • Good quality of English expression is demonstrated, and its language is clear and concise.
  • The report is sectioned properly to aid the overall argument.
  • All figures and tables are labelled properly and discussed in the text.
  • Figures and tables are relevant and informative.
  • Correct citation and reference styles are used in accordance with the suggested referencing system.
  • Good use of visual aids is demonstrated.
• Introduction and background (/15%)
  • A clear statement about why the report was commissioned in the first place.
  • Comprehensive, detailed and focused context about the presented work is given.
  • Succinctly lead the reader to the purpose of the work being documented.
  • The objectives of the work are expressed well.
  • Previous reports and research, if the present report builds on, are included.
• Methods and results (/20%)
  • Detailed information on the approach and/or materials used in the study
  • Sufficient references are provided to support the methodology used in the report.
  • Results are presented in a logical way.
  • Clear but concise evidence in the form of statistics, graphs and tables
  • Justification for conclusions and recommendations
• Discussion (/15%)
  • Analysis using your own words on the method and results
  • Good interpretation and explanation of the results
  • Relation of the results with the literature
  • Examine whether and how the questions raised in the introduction have been answered
• Conclusions (/10%)
  • Clear agreement with all the objectives that were set out in the introduction is made.
  • The significant findings and elements from the report are highlighted.
  • The main points of the report are drawn.
  • A clear statement about how the topic relates to its context (an evaluation of the importance of the topic, implication and/or recommendation for future studies)