203 Flashcards

Flashcards from the slides

Mechatronic System

Any system that integrates elements of electro-mechanical and electronic (i.e. semiconductor) components to achieve some utilitarian purpose.

Robotics according to Gammell

A (re)programmable system that is able to automatically execute physical tasks

Robotics according to IEEE

An autonomous machine capable of sensing its environment, carrying out computations to make decisions, and performing actions in the real world.

Robotics Manipulator Properties

High DOF
Geometric Constraints
One (or more) fixed point(s)
Known operating environment

Robotic Vehicle Properties

Low degrees of freedom
Kinematic constraints
No fixed point
Uncertain/changing operating environments

Navigation Components

• localization

• estimates the robot’s state

• mapping

Guidance Components

• Decide a path or trajectory for the robot

• deals with long range and short range problems

Control Components

• Computes input commands

• requires output from both navigation and guidance

• responsive enough to track motion within acceptable error

Functional Subsystems

Guidance, Navigation, Control

Design Cycle

1. Conceptual system design

2. System model development

3. Computer-based simulation

4. System functionality development

5. Prototyping in simulation

6. Hardware Prototyping

7. Physical testing

Proportional Control Model

u(t) = k_p * (v_d - v_est(t)) := k_pV_error(t)

Proportional Control on a slope

u(t) - mgsinθ = m * dv/dt

PI controller

u(t) = k_p(v_d(t) - v_est(t)) + k_I ∫^t₀ (v_d(T) - v_est(T)dT

Input Saturation

the controller is pushing for an output that is beyond what is possible by the hardware (i.e. getting 255 pwm constantly)

Anti Windup

prevents the integral term from accumulating excessive error when the actuator saturates

Derivative term for control

k_D*d/dt(x_d-x_est)

Systems Engineering according to NASA

systems engineering is the art and science of developing an operable system capable of meeting requirements within often opposed constraints

Systems Engineering Workflow

stakeholder expectations → operational concepts & constraints → technical requirements → technical solution → design realization → evaluation

Technical Requirements

what “the system shall do”

• must include a set of measures that can be evaluated

Functional Requirements

a relation between input and output

what functions need to be done to accomplish the design objectives

Non-functional Requirements

overall characteristics of the system, but not compulsory for operation

(e.g. cost, reliability, performance)

Legal Definition of Engineering

The practice of engineering means any act of planning, designing, composing, evaluating, advising, reporting, directing, or supervising, or managing any of the foregoing, that requires the application of engineering principles and that concerns the safeguarding of life, health, property, economic interests, the public welfare or the environment.

Types of engineering malpractice

misconduct, negligence, incompetence, corruption, breaches of the code of ethics

Engineers Canada Responsibilities

1. promotes engineering nationally

2. coordinates policies and positions

3. accredits undergraduate engineering programs

4. assesses internationally trained engineers

Professional Engineers Ontario responsibilities

• promotes the engineering profession

• licenses and regulates engineering practice in Ontario

• enforces a code of ethics

• serves and protects public interest

T/F Software developers hold blame for engineering accidents

F: legal liability for an engineering failure cannot be transferred to a software developer

Discipline-focused team

• focused on a single technical area, may be several in a company

• level of autonomy between teams varies

• team members report to a team leader in their technical field

Product/Project-Focused Team

• team is centered on a product, feature, or output (e.g. user interface, navigation etc)

• team members report to a product lead

• closely aligned with business success

• encourages collaboration

• might distract from engineering excellence

Matrix Structure

Temporary project managed by a project manager, populated by specialists from different disciplines (or lines) that are managed by a discipline/line manager

Which is correct?

present tense: figure 1 illustrates

T/F: units should be italicized

False

T/F Generally, there should be a space between numbers or variables and their units

True

When should you not put a space between numbers and units

for coordinates in degrees, minutes, seconds

Rules for equation formatting

Equations/maths are part of a sentence and much be punctuated.
variables are always italicized (but not units or words)

they are numerated with round brackets e.g. (1)

What does “as” mean in engineering writing?

while

formula for $ at end with compound interest after n years

p(1+i)ⁿ

Internal Rate of Return

what happens when the Net Present Value is zero. (we would not have made more by investing our initial capital)

Isaac Asimovs laws of robotics

1. A robot may not injure a human being or, through inaction, allow a human being to come to harm

2. A robot must obey the orders given it by human beings except where such orders would conflict with the first law

3. A robot must protect its own existence as long as such protection does not conflict with the first or second law

0. A robot may not harm humanity, or, by inaction, allow humanity to come to harm.

Laws of responsible robotics

1. A human may not deploy a robot without the human-robot work system meeting the highest legal and professional standards of safety and ethics

2. A robot must respond to humans as appropriate for their roles.

3. A robot must be endowed with sufficient situated autonomy to protect its own existence as long as such protection provides smooth transfer of control to other agents consistent with the first and second laws.

Ethical Duty Theory

Every individual has a fundamental duty to act in a correct an ethical manner

It is the intention to do one’s duty that is significant, NOT the actual consequences. (intention over action)

Rights Ethics

Every individual has rights simply by virtue of their existence

The right to life and the right to the maximum possible individual liberty and human dignity are fundamental

Utilitarianism Ethics

The best choice is the one which produces the maximum benefit for the greatest number of people

benefit can be hard to quantify

Virtue Ethics

find the golden mean between the extremes of excess and deficiency

Intellectual Responsibility

The act of using your engineering and design work - and the work of others - responsibly in the context and under the protections of intellectual property laws.

Intellectual Property

A work or invention that is the result of creativity, such as a manuscript or a design, to which one has rights.

Types of intellectual property

Trademarks

Copyrights

Trade Secrets

Patents

Trademark

Combination of letters, words, sounds or designs that distinguishes one company’s goods or services from those of others in the marketplace

Copyright

Exclusive legal right to produce, reproduce, publish or perform an original literacy, artistic, dramatic or musical work

T/F you need to register your copyright

F: registration is not required unless you need to legally enforce the copyright

Creative Commons License

allows creators to easily grant permission to others to use and share their work under certain conditions

Trade Secret

Confidential information that derives economic value from not being generally known by others (e.g. coca cola recipe)

Patent

gives the inventor the right to stop others from making, using or selling the invention for max 20 years, within the jurisdiction

gives a temporary monopoly, but you must disclose how the invention works

what is patentable

inventions which are:

• novel

• useful

• inventive

What may not be patented

abstract ideas or theories, art, medical treatments or methods, forms of energy, printed matter, math, physical phenomena

LifeCycle Stages

1. Create

2. Make

3. Use

4. Renew

Life Cycle Considerations

Energy and emissions

Materials and waste

Natural Resources

MTBF and f(t) for constant failure rate

MTBF = 1/λ

f(t) = λe^-λt

Failure rate for a series system

λ_s(t) = Σλ_i(t)

model for a system where one component causes the entire system to fail

series connection

model for a redundant system

parallel connections

R(t)/F(t) for series interconnections

reliabilities are multiplied

parallel interconnections

failures are multiplied

Active Redundancy

All components are running at the same time

Is redundancy more impactful during the beginning or end of life

At the beginning of life, when reliability is larger

Which is better: Component or System redundancy?

Component redundancy EXCEPT when cost, increased complexity and resource cost are constrained.

Risk Priority Number

Severity x Occurrence x detection

Ingress Proection Rating

2 digits: dust protection (0-6) and water protection (0-8)

FMEA + steps

Failure modes & effect analysis

1. identify potential failure modes

2. determine potential effects of each failure mode

3. assign severity scores for each potential effect (high is bad)

4. identify potential causes of each failure mode

5. assign occurrence scores for each potential cause (high is bad)

6. identify existing controls

7. assign detection scores for each control (high is bad)

8. calculate RPN

9. take action to reduce high RPN

How to combine failure rates in series and parallel

series: add them

parallel: you need to do the reliabilities

SI standard units

• Metre

• Kilogram

• Second

• Ampere

• Kelvin

• Mole

• Candela