electronics and robotics

ELECTRONICS IN ROBOTICS

BY HUMANOIDS

ROBOT’S ORIGIN………………

• The word ‘ROBOT’ was coined by a CzechNovelist Karel Capek in a 1920 play titled Rossum’s Universal Robots(RUR).• ‘Robota’ in Czech defines a worker or a servant.

Karel Capek

ROBOT

Mechanical Software Components Programs

Electronic components

IR Emitters & PowerDetectors regulators

Sensors Motors Voltage Regulators

ROBOT MOTORS

ELECTRIC MOTOR: An electric motor is an electro chemical

device that converts electrical energy into mechanical energy.

• Electric motors are driven by DC current.• They are most commonly used in hobbyist robot

applications.

TYPES OF MOTORS:1. Brushed DC motors:• Motor controller is used to rotate the motor in two

directions.• It is quite expensive.• Pulse-width modulation.• Gear reducer is used to reduce speed and increase

torque

2. Brushless DC motors:•Electronic speed control unit is used.•Still, these are widely used in RC community because they offer greater reliability, torque and have other good characteristics.

3. Stepper motors:•Magnetic poles on stator.•Provide current to the coils at a predefined sequence.•Special stepper motor controller.

4. Servo motors:•Servo motors are integrated with control system.•They include other types of motors such as pneumatic or hydraulic as long as the feedback system is present in provide positioning.•Pulse width modulation.•Used to construct robot arms.

ROBOTIC ARM:•Robotic arm is a robotic manipulator, usually programmable with similar functions to a human arm.•Servo motor is used for joint rotation.•We can control arm through computer interface.

SALIENT FEATURES OF A ROBOTIC ARM.•Five servos which are controlled through only one microcontroller ATMEGA16.•Used to grab things in the hemisphere of 50cm.•It is user friendly.•It can lift objects weighing 200gms and above.•To keep the design of robotic arm gripper simple, and implementing the gripping mechanism without gears with one servo motor.

SENSORS

A Device that detects a physical property and responds to it

•LIGHT SENSORS•SOUND SENSORS•CONTACT SENSORS•PRESSURE SENSORS•TEMPERATURE SENSORS

•PROXIMITY SENSORS•RANGE SENSORS

LIGHT SENSORS•Used to detect light and create a voltage difference.

SOUND SENSORS•Detects sound and returns voltage proportional to sound level.

TEMPERATURE SENSORS•Generally used temperature sensors are LM34,LM35,TMP35,TMP36 and TMP37.

CONTACT SENSORS•Require physical contact to function.

PRESSURE SENSORS• pressure sensors

measures pressure

Proximity sensors

IR Transeivers Ultrasonic sensor

Photoresistor

Range sensors

Ultrasonic Stereo Range sensor camera

IR range Laser range EncodersSensors Sensors

DESIRABLE FEATURES OF SENSORS

Accuracy Precision Operating range Speed of response Calibration Reliability Ease of operation Cost

What is the role played by sensors in robotics?•To maintain its stability and orientation.

•Report position and speed.

•Interaction with surroundings.

•Distinction of objects.

•To mimic sensory abilities of humans.

INFRARED EMITTERS AND DETECTORS

•Side looking Infrared Emitters and Detectors.

•The Parts-emitter and detector.

•The Schematic-IR detection module,oscillator

APPLICATIONSGeneric IR systems.Remote Control.Touchless object sensing.

int CheckForObstacle;{int ReturnValue;TurnOnEmitter(LEFT);if(DetectorSeesLight()) { ReturnValue=LEFT; }TurnOffEmitter(LEFT);TurnOnEmitter(RIGHT);if(DetectorSeesLight()) { ReturnValue=ReturnValue+RIGHT; }TurnOffEmitter(RIGHT);return ReturnValue;

How are IR Emitters and Detectors

used in robots?

•Line following robots.

•Obstacle Detection.

•Motion Detection.

•Colour Detection.

VOLTAGE REGULATION

What is a voltage regulator?A device designed to automatically maintain constant

voltage level.

TYPES OF VOLTAGE REGULATORS1) Electronic voltage regulators.2) Electrochemical regulators.3) Coil-rotation AC voltage regulator.4) Active regulators- linear, switching and SCR.

1. Electronic- A simple voltage can be

made from a resistor in series with diodes.

2. Coil-rotation AC- Basic design principle

1. Linear regulators- These regulators comprise of devices that operate in their linear region.

2. Switching regulators- They rapidly switch a series device on and off.

FUNCTIONS OF VOLTAGE REGULATORS

Passive voltage regulators.

Active voltage regulators.

AC voltage stabilization.

DC voltage stabilization.

Coil rotation AC voltage regulators.

H-BRIDGES:

•A circuit for driving DC motors is called H-bridge.

•The great ability of a H-bridge circuit is that the motor can be driven forward or backward at any speed. `

POWER REGULATION

• Supply a minimum required amount of power

POWER=VOLTAGE*CURRENT• Capacitor is used to store large quantities

of energy.

FUTURE OF ROBOTICS

•Industrial robots.

•Military and police organizations.

•Surgical robots.

•100% automated factories.

•Robot astronauts.

THANK

YOU