Unit 2: Fundamental of Robotics

Unit 2: Fundamental of Robotics

5 Major Components of a Robot

Controller

Manipulator

End effector

Power supply

Programming.

Draw this in your engineering notebook

Controller

• The controller is a microprocessor linked to input/output and monitoring devices. It coordinates all movements of the mechanical system. It also receives input from the immediate environment through various monitoring devices.

Manipulator

• A manipulator is the arm of the robot that is used to move materials, parts, tools, or special devices through various

  motions to provide useful work.

End Effector

• is a device attached to the wrist of the manipulator for the purpose of grasping, lifting, transporting and maneuvering

• This acts as the "hand" for the robot.

• Small swing arms can be attached to the end of a primary arm. 

End Effector

• Arms are usually attached to a tower on the robot chassis and are used to lift another manipulator on the end of the arm.

• Arms can also be used to lift the robot off of the ground if this is part of the game's scoring.

• Arms frequently use rubber bands or latex tubing to assist with lifting.

• Motors are usually mounted to the tower and drive a gear train, chain and sprocket system, or a Turntable Bearing which is attached to the arm.

Multiple Choice

What determines the shape of the work envelope for a robot?

• The type of coordinate system, the arrangement of joints, and the length of the manipulator segments determine the shape of the work envelope.

• To identify the maximum work area, a point on the robot wrist is used rather than the tip of the gripper or the end of the tool bit.

• Therefore, the work envelope

  is slightly larger when the tip of the tool is considered.

• All of the above.

Power Supply

• The power supply is a mechanism that provides the energy to drive the controller and actuators.

Power Supplies

• electrical

• hydraulic

• pneumatic

Electricity

The power supply provides the energy to drive the controller and actuators. It may convert ac voltage to the dc voltage required by the robot’s internal circuits, or it may be a pump or compressor providing hydraulic or pneumatic power.

Multiple Choice

Which is the most common energy source available, where industrial robots are used?

• Electrical (quiet, simple)

• Hydraulic (linear and rotary motion)

• Pneumatic (air)

Programming

• A robot may be programmed using any of several different methods

• Programs are instructions that are saved to the controller.

• For Vex we will use Blockly and Python programming

Blockly Programming

• simple drag and drop interface to create functioning projects.

• each block's purpose can easily be identified using the visual cues like its shape, color, and label.

Teach Pendant

• connected to a controller and is used to teach a robot how to complete a task.

• also called a teach box

• records movements into the robot's memory

Draw this in your engineering notebook

Multiple Choice

What is the technical name for the device that acts as a “hand” for a robot?

• Hydraulic

• Pendant

• End Effector

• Controller

Degrees of Freedom

DOF provides maximum flexibility for a robot

Work Envelope

• many sizes and shapes.

• depends on the type of coordinate system, the arrangement of joints, and the manipulator also varies.

• 4 major configurations are: revolute, Cartesian, cylindrical, and spherical.

Why should you be concerned about the work envelope shape when installing a robot for a particular application?

Write answer in your engineering notebook.

To identify the maximum work area, a point on the robot wrist is used rather than the tip of the gripper or the end of the tool bit. Therefore, the work envelope is slightly larger when the tip of the tool is considered.

Compare this to the answer in your engineering notebook.

Why should you be concerned about the work envelope shape when installing a robot for a particular application?

Write answer in your engineering notebook.

Work envelopes vary from one manufacturer to another, depending on the exact design of the robot arm. Combining different configurations in a single robot can result in another set of possible work envelopes. Before choosing a particular robot configuration, the application must be studied carefully to determine the precise work envelope requirements.

Compare this to the answer in your engineering notebook.

Servo-Robots

Servo robots can be classified as intelligent or highly intelligent. These are closed-loop systems because it allows for feedback.

Non Servo-Robots

Non-servo robots are limited in their movements and these limitations are ususally in the form of a mechanical stop.

Characteristics of non-servo robots:

Relatively inexpensive compared to servo robots.

Simple to understand and operate.

Precise and reliable.

Multiple Choice

Non-Servo robots have sensors.

• True

• False

Multiple Choice

The principle of servo control can be compared to

many tasks performed by human beings.

• True

• False