Introduction to Robots

History of Robots

What is a Robot? Many different definitions for robots exist: Many devices with varying degrees of autonomy are called robots. Some consider machines wholly controlled by an operator to be robots. Others require a machine be easily reprogrammable.

What is a Robot? Many different definitions for robots exist: A machine design to carry out a specific task. A machine capable of carrying out a complex series of actions automatically, especially one programmable by a computer.

Robot Classes Manipulators: robotic arms. These are most commonly found in industrial settings.

Robot Classes Mobile Robots: unmanned vehicles capable of locomotion.

Robot Classes Hybrid Robots: mobile robots with manipulators.

Robot Classes Bipedal Robots: its body shape is built to resemble the human body.

A cyborg (short for "cybernetic organism") is a being with both organic and biomechatronic body parts.

Robot Components Body End Effectors Actuators Sensors Computer hardware Computer software Networking and communication Power source

Robot Body Typically defined as a graph of links and joints

Types of Joints A ball joint allows rotation around x, y, and z axis.

Types of Joints A hinge joint allows rotation around x or y axis.

Types of Joints A slider joint, which allows translation along y or x axis.

Robot End Effectors An end effector is the device at the end of a robotic arm, designed to interact with the environment. The exact nature of this device depends on the application of the robot.

Robot End Effectors

Robot End Effectors End effectors accomplish some desired physical functions or task. Examples: Hands: griping Tools: drill, torch, arc welder Wheels: lateral movement Legs: lateral movement and climing

Robot Actuators An actuator is a mechanism for activating process control equipment by the use of pneumatic, hydraulic, or electronic signals Actuators are the “muscles” of the robot. Actuators provides propulsion and gives physical strength to the robot.

Robot Actuators These can be electric motors, hydraulic systems, pneumatic systems, or any other system that can apply forces to the system.

Robot Actuators

Robot Sensors

Human sensing and organs Vision: eyes (optics, light) Hearing: ears (acoustics, sound) Touch: skin (mechanics, heat) Odor: nose (vapor-phase chemistry) Taste: tongue (liquid-phase chemistry)

Definition Sensor: A device which provides information about the physical world. Note use of word “information”. In other words, sensors are usually thought of as being the interface between a information processing system and the physical world.

Definition Transducer: A device which converts energy from one form to another. Sensors are based on a transduction principle - conversion of energy from one form to another Note use of word “information”. In other words, sensors are usually thought of as being the interface between a information processing system and the physical world. Sensors are transducers.

Robot Sensors Why do Robots Need Sensors? What can be Sensed? What Sensors are Out There? What can They do?

Sensors - What Can Be Sensed? Light Presence, color, intensity, content (mod), direction Sound Presence, frequency, intensity, content (mod), direction Heat Temperature, wavelength, magnitude, direction

Sensors - What Can Be Sensed? Chemicals Presence, concentration, identity, etc. Object Proximity Presence/absence, distance, bearing, color, etc. Physical orientation/attitude/position Magnitude, pitch, roll, yaw, coordinates, etc.

Why Do Robots Need Sensors? Provides “awareness” of surroundings What’s ahead, around, “out there”? Allows interaction with environment Robot lawn mower can “see” cut grass Protection & Self-Preservation Safety, Damage Prevention, Stairwell sensor Gives the robot capability to goal-seek Find colorful objects, seek goals

Why do robots need sensors? What is the angle of my arm? Internal information

Why do robots need sensors? Were am I? location

Why do robots need sensors? Will I hit anything? obstacle detection

Types of Sensors Sensors can be Active or Passive: Active Sensors sends signal into the environment and measure the interaction of the signal with environment. Example: radar & sonar Passive Sensors record signals already present in the environment. Example: video cameras

What Sensors Are Out There? Feelers (Whiskers, Bumpers) – Active Next we are going to look at what’s out there to make these measurements. In a word “LOTS”. There are sensors you can build out of cannibalized parts, junk, or whatever. There are also many sensors that you can buy, ready to interface to a robot’s controller. The next couple slide cover a lot of them.

Feelers - Whiskers Pictures of feelers or whiskers.

Feelers - Bumpers & Guards Pictures of bumpers.

What Sensors Are Out There? Feelers (Whiskers, Bumpers) – Active Photoelectric (Visible) – Active & Passive Infrared (light) – Active & Passive Next we are going to look at what’s out there to make these measurements. In a word “LOTS”. There are sensors you can build out of cannibalized parts, junk, or whatever. There are also many sensors that you can buy, ready to interface to a robot’s controller. The next couple slide cover a lot of them.

Photoelectric – Active Sensor Picture of an active IR sensor system.

What Sensors Are Out There? Feelers (Whiskers, Bumpers) – Active Photoelectric (Visible) – Active & Passive Infrared (light) – Active & Passive Ultrasonic (sound) – Active & Passive Next we are going to look at what’s out there to make these measurements. In a word “LOTS”. There are sensors you can build out of cannibalized parts, junk, or whatever. There are also many sensors that you can buy, ready to interface to a robot’s controller. The next couple slide cover a lot of them.

Ultrasonic – Active Sensor $27 Picture of components and sub-systems for ultrasonic ranging systems. $134 $49

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