Degrees of Freedom, Kinematic Diagram, DH Frames

What does "degrees of freedom" refer to?

The smallest set of independent parameters required to fully characterize a mechanical manipulator

How does degrees of freedom relate to a robot's movement?

It determines how freely a robot can move and interact with its surroundings

What analogy is used to explain degrees of freedom?

A mysterious 3D object suspended in space

How are degrees of freedom represented in the analogy?

By using Cartesian coordinates X and Y for position and orientation

How many degrees of freedom does a point have in 2D space?

Two (X and Y)

How many degrees of freedom does a point have in 3D space?

Three (X, Y, and Z)

Give an example of a rigid body with six degrees of freedom.

A flying plane

What are the three rotational axes for a flying plane's movement?

Roll, pitch, and yaw

What are under-activated manipulators characterized by?

Fewer degrees of freedom than the maximum possible for their category

Name two categories under under-activated manipulators.

Spatial manipulator with less than six degrees or planar manipulator with less than three degrees

What do ideal manipulators have regarding their degrees of freedom?

The maximum possible number for their category (six for spatial, three for planar)

Define redundant manipulators.

Manipulators that provide more degrees of freedom than necessary for their task

In terms of mobility, what happens when a spatial manipulator has more than six degrees of freedom?

It gains extra mobility beyond what's required \n

How many degrees of freedom does a planar manipulator typically have?

Three

What is the purpose of Gruebler's Criterion in calculating degrees of freedom?

To provide a structured approach for accurate calculations

What does CI represent in Gruebler's Criterion?

The connectivity of a joint in the manipulator

How are degrees of freedom related to a manipulator's capabilities and applications?

Degrees of freedom determine the flexibility and potential movements of a manipulator

Why is understanding degrees of freedom important in analyzing manipulator designs?

It helps ensure that the design can perform the required tasks effectively

How does Mobility differ from Degrees of Freedom?

Mobility refers to extra motion beyond what's required, while Degrees of Freedom represents the minimum parameters needed for motion description.

What are some factors that can influence actual movement despite ideal degrees of freedom counts?

Mechanical constraints and limitations

How can Degrees of Freedom help optimize a manipulator's performance?

By considering the balance between ideal configuration, potential mobility, and required task performance.

What are some characteristics of an under-activated manipulator?

Fewer degrees than maximum, limited flexibility/control

What are some characteristics of an ideal manipulator?

The maximum possible degrees for its category, balanced flexibility/control

What are some characteristics of a redundant manipulator?

More degrees than necessary, versatile and adaptable

How does Gruebler's Criterion help calculate degrees of freedom for spatial and planar manipulators?

It provides mathematical formulas based on joint connectivity to determine mobility/degrees.

What formula can be used to calculate the mobility or degreees of freedom for spatial manipulators according to Gruebler's Criterion?\n6n - summation(M from I=1)(6 - CI) \nWhat formula can be used to calculate the mobility or degreees of freedom for planar manipulators according to Gruebler's Criterion?\n

3n - summation(M from I=1)(3 - CI)

What formula can be used to calculate the mobility or degreees of freedom for spatial manipulators according to Gruebler's Criterion?\n

6n - summation(M from I=1)(6 - CI)

What is kinematics?

The science of motion that treats the object without regard to the forces that cause it

What does a kinematic diagram show?

How the links and joints are connected together when all joint variables have a value of zero

Where can you find kinematic diagrams in robotics research papers?

In the psrf and RN Panela Goose modeling and simulation of a point-to-point spherical articulated manipulator using optimal control

What are the basic parts of a kinematic diagram for a mechanical manipulator?

Base, joints, links, and end effector

What types of joints are needed in constructing a kinematic diagram?

Twisting/revolute joints and prismatic/orthogonal joints

How are twisting/revolute joints represented in a kinematic diagram?

As cylinder-shaped representations or servo motors with stator and rotor components

How are prismatic/orthogonal joints represented in a kinematic diagram?

As cubes with projecting squares to indicate the direction of translation

What is an example of a three degrees of freedom cylindrical spatial manipulator?

A cylindrical manipulator with revolute and prismatic joints

What views are projected when drawing the kinematic diagram for a mechanical manipulator?

Front view, right side view, and top view

What is the topic of the lecture?

Kinematic Diagram Part 2

Where can the lecture be found?

YouTube

What are the basic components of a kinematic diagram?

Links and joints

How are links defined in a kinematic diagram?

Rigid parts of a mechanical manipulator

What does the double-headed arrow indicate in a kinematic diagram?

Connection between links

How are revolute joints indicated in a kinematic diagram?

Rotating counterclockwise arrow (Theta)

How are prismatic joints indicated in a kinematic diagram?

Arrow with a flat line (d)

What is the end effector in a kinematic diagram?

The last point of the mechanical manipulator

How are link lengths labeled in a kinematic diagram?

a sub 1, a sub 2, etc.

What do joint variables represent in a kinematic diagram?

Values that change when the joint moves

How are rotation angles labeled in a kinematic diagram?

Theta (Θ)

Which direction represents positive rotation angles in robotics?

Counterclockwise

What units can rotation angles be expressed in?

Radians or degrees

What do translation lengths represent in a kinematic diagram?

Displacement or translation links (d)\ne

Are translation lengths always positive or negative values?\n

Always positive

What is D-H Notation?

Dena with Hartenberg notation.

Who introduced D-H Notation?

Jack's Denavit and Richard Hartenberg.

When was D-H Notation introduced?

1955

What is the purpose of D-H Notation?

To standardize coordinate frames for spatial linkages.

What is a kinematic diagram used for?

Analyzing and designing mechanical manipulators.

How many types of frames are used in a mechanical manipulator?

Three: base, user, tool.

Where are the frames located in a mechanical manipulator?

Base, joints, end effector.

What are the DH frame rules used for?

Assigning frames in the kinematic diagram.

What are the DH frame rules used for assigning frames in a kinematic diagram called?

DH frame rules.

How many DH frame rules are there?

Four DH frame rules.

What is Rule 1 of DH frame rules?

Decide on three views: front view, right side view, top view.

What is Rule 2 of DH frame rules?

Identify the center/origin of each frame using link indicators/arrows.

What is Rule 3 of DH frame rules?

Draw color-coded arrows based on decided three views (x-axis: red arrow, y-axis: green line, z-axis: vertical line).

What is Rule 4 of DH frame rules?

Make the arrows of z-axis and x-axis easy to see for future computations.