20-08-2014, 02:41 PM
ROBOT MOTION AND LEG MECHANISMS
ROBOT MOTION.docx (Size: 18.23 KB / Downloads: 9)
Introduction :
The term robot derives from the Czech word robota, meaning forced work or compulsory service, or robotnik, meaning serf. Robot can be defined as "A reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through various programmed motions for the performance of a variety of tasks”.
Robotics has matured as a system integration engineering field defined by M. Bradley as “the intelligent connection of the perception to action”. Programmable robot manipulators provide the “action” component. A variety of sensors and sensing techniques are available to provide the “perception”.
Sensor - an electrical/mechanical/chemical device that maps an environmental attribute to a quantitative measurement. Collect information about the world. Each sensor is based on a transduction principle - conversion of energy from one form to another. Also known as transducers.
DIFFERENT TYPES OF SENSORS
Tactile Sensors: it is used to tell us if we hit something.
Examples of tactile sensors: Magnetic, Ultrasonic, Microwave and Optical.
Time of Flight sensors: it is used to tell us how far objects are from us
Examples of tactile sensors: Ultrasonic and Laser - Based
Compasses: it is used to measure which way is north
Examples of compasses: Mechanical, Fluxgate and Hall-Effect.
Misellaneous: it is used to tell us things about our environment.
Examples of miscellaneous: Gyroscopes, Motion Detection, Smoke, Pressure, Temperature.
Simple commonly used practical Sensors
Touch sensors
Tilt sensors
Encoders
Bend sensors
Light sensors
Temperature sensors
Potentiometer
Laser rangefinders
Cameras
Tactile Sensors
Tactile sensors are devices which indicate contact between themselves and some other solid object. Mainly used for collision detection. If the switch connects, electricity passes and we can detect a “hit”.
Desirable Features of the sensors
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Accuracy
Precision – series of measurements will be minimized
Speed of response
Calibration – Sensors should not require frequent calibration
Reliability
Cost and ease of operation
Uses of sensors in robotics
Safety monitoring
Interlocks in work cell control
Part inspection for quality control
Determining positions and related information about objects in the robot cell