TECHNOLOGYIN ROBOTICS

ROBOT BASIC COMPONENTS• MECHANICAL FLATFORMS/ HARDWARE BASE

-mechanical device capable of interacting with its environment and any other mechanism involve with his capabilities and uses.

• SENSOR SYSTEMS-provide judgment to the controller with relevant information

about the environment and give useful feedback to the robot.

• JOINTS-provide more versatility to the robot itself and are not just a

point that connects two links or parts that can flex, rotate, revolve and translate

• CONTROLLER- "brain" of the robot. Robots today have controllers that

are run by programs - sets of instructions written in code. In other words, it is a computer used to command the robot memory and logic. So it, be able to work independently and automatically.

- Is a communication, information processing device that initiates, terminates and coordinates the motion and sequences of a robot.• Robots are often classified under the three major categories

according to the type of control system used:• NONSERVO – Open loop system• SERVO – closed loop system• SERVO-CONTROLLED – closed loop system with continously

controlled path.

• POWER SOURCE-main source of energy to fulfill all the robots needs.

It could be a source of direct current as a battery, or alternate current from a power plant, solar energy, hydraulics or gas.*There are three basic types of power supplies:

-ELECTRIC-HYDRAULIC-PNEUMATIC

• ARTIFICIAL INTELLIGENCE-represents the ability of computers to "think" in ways

similar to human beings.-Present day "AI" does allow machines to mimic certain

simple human thought processes, but can not begin to match the quickness and complexity of the brain.

• MANIPULATOR- Primary function is to provide the specific motions that

will enable the tooling at the end to do the required work.

• END EFFECTOR- The device that is mechanically opened and closed.- Depending on the type of operation, conventional end

effectors are equipped with various device and tool attachments

• * The simplest behavior of a robot is LOCOMOTION. Typically, joints and wheels are used as the underlying mechanism to make a robot move from one point to the next.

This type of motion should include the adaptability and versatility of the robot to continue with a specific task. *Adaptability means adjustment to the task being carried out. *Versatility means that the robot should have such a mechanical structure that it can carry out different tasks or perhaps the same task in different ways.

DEGREE OF FREEDOM- defined as the direction in which a robot moves when a joint

is actuated.- Each joint usually represent one degree of freedom.- Most of the robots used today use five or six degrees of freedom. But this depends on the robot application, for example a pick-and-place application need only three axes specified when a welding robot requires five or six degrees of freedom.

TYPES OF JOINT LINKS OF A MANIPULATOR MECHANISM

• ROTARY OR REVIOLUTE JOINTS- the most utilized joint and it rotates along the pin as an

axis.• SPHERICAL JOINTS

- the third most utilized joint and just slide causing a revolving movement.• SCREW JOINTS

- follow the thread of the axis in spiral to move along the axis.

• CYLINDRICAL JOINTS- are very rare and are use in some equipment like

Parallel Robots or Flying simulator Mechanism.

• PRISMATIC OR SLIDING JOINTS- are very rare and are use in some equipment like

Parallel Robots or Flying simulator Mechanism.

ROBOTIC SENSORS• The word sensor comes from the word sense and it is originate

from the Middle French sens, sensation, feeling, and mechanism of perception.

• Improves the performance of the robots it must be able to sense in both ways their internal and external states (the environment) to perform some of the tasks presently done by humans.

• more accurate and intelligent robots are expected to emerge with the newly developed sensors, especially visual sensors. Vision provides a robot with a sophisticated sensing mechanism that allows the machine to respond to its environment in an intelligent and flexible manner.

DIFFERENT TYPE OF SENSORS• PROXIMITY SENSOR

- senses and indicates the presence of an object within a fixed space near the sensor without physical contact. Different commercially available proximity sensors are suitable for different applications.

• RANGE SENSOR- measures the distance from a reference point to a set of

points in the scene. - Range can be sensed with a pair of TV cameras or sonar

transmitters and receivers.

• TOUCH SENSOR- senses and indicates a physical contact between the

object carrying the sensor and another object. - The simplest touch sensor is a micro switch. Touch

sensors can be used to stop the motion of a robot when its end-effectors make contact with an object.

• ACOUSTIC SENSOR- senses and interprets acoustic waves in gas, liquid, or

solid. - The level of sophistication of sensor interpretation

varies among existing acoustic sensors, frequency of acoustic waves and recognition of isolated words in a continuous speech.

• FORCE SENSOR- measures the three components of the force and three

components of the torque acting between two objects

ELECTRIC MOTOR• machine which converts electric energy into mechanical

energy.• A variety of electric motors provide power to robots, allowing

them to move material, parts, tools, or specialized devices with various programmed motions.

• The efficiency of a motor describes how much of the electrical energy utilize is converted to mechanical energy.

*The difference between Direct Current (DC) and Alternating Current (AC) electric current is the way that electrons travel in the wire connections

• ALTERNATING CURRENT (AC)- type of electricity that we get from plugs in the wall.- switch their direction of flow back and forth.

• DIRECT CURRENT (DC)- electric charges flow always in the same direction.

DIFFERENT TYPES OF MOTORS• Direct Current (DC) motor

-switches the direction of the electric current at each half of the rotation of the rotor

• Brushless DC Motors- this motor reduced maintenance, no spark hazard, and

better speed control. They are widely used in computer disk drives, tape recorders, and other electronic devices.

• Alternating Current (AC) motor

• Synchronous AC Motors

• Universal Motors

6 COMMON TYPES OF ROBOT SYSTEMS

• CARTESIAN ROBOT- These robots move in three directions, in translation, at

right angles to each other.- form by 3 prismatic joints, whose axes are coincident

with the X, Y and Z planes.

• SCARA ROBOT-Selective Compliance Assembly Robot Arm-is built with 2 parallel rotary joints to provide

compliance in a plane. The robots work in the XY-plane and have Z-movement and a rotation of the gripper for assembly.

• CYLINDRICAL ROBOT-able to rotate along his main axes forming a cylindrical

shape.-The robot arm is attached to the slide so that it can be

moved radially with respect to the column.

• ARTICULATED ROBOTS-They are used in welding and painting; gantry and

conveyor systems move parts in factories. -mechanic manipulator that looks like an arm with at

least three rotary joints.

• SPHERICAL ROBOT-It used for a small number of vertical actions and is

adequate for loading and unloading of a punch .-is able to rotate in two different directions along his

main axes and the third joint moves in translation forming a hemisphere or polar coordinate system.

• PARALLEL ROBOT-complex mechanism which is constituted by two or more

kinematics chains between, the base and the platform where the end-effectors are located.

-Good examples are the flying simulator and 4-D attractions at Univ. Studios

TYPES OF ROBOTS ACCORDING TO APPLICATION

• INDUSTRIAL ROBOTS- includes the automobile and manufacturing industries.

• EDUCATIONAL ROBOTS- Their role is demonstrational for teaching basic concepts .

• AGRICULTURAL ROBOTS- one example is the Demeter harvester it contains new

controllers, proximity sensors, safeguards and task software specialized to the needs of commercial agriculture processes

-

• ROBOTS IN SPACE- Remotely Operated Vehicle (ROV).- It can be consistent with an unmanned spacecraft that

remains in flight or a lander that makes contact with an extraterrestrial body and operates from a stationary position, or a rover that can move over terrain once it has landed.

• MOBILE ROBOTS(TRANSPORTATION)- these types of robot operate by control remote

deploying sensor position. - consist of sampling payloads, mapping surface and

creating a photorealistic 3D models and sent back any kind of visual information of building interiors and any environmental data.

• HEALTH CARE ROBOTS- perform simple task and improve some medical

protocol and procedures.

OTHER TYPES:• ROLLING ROBOTS

- have wheels to move around. These are the type of robots that can quickly and easily search move around. However they are only useful in flat areas.

• WALKING ROBOTS- . Development of legged robots is often modeled after

insects or crawfish- Robots on legs are usually brought in when the terrain is

rocky and difficult to enter with wheels. Robots have a hard time shifting balance and keep them from tumbling. That’s why most robots with have at least 4 of them, usually they have 6 legs or more.

• STATIONARY ROBOTS- Most robots perform repeating tasks without ever

moving an inch. - In case the tasks at hand are done, the robots will be

reprogrammed to perform other tasks

• AUTONOMOUS ROBOTS- are self supporting or in other words self contained. In

a way they rely on their own ‘brains’.- run a program that give them the opportunity to decide

on the action to perform depending on their surroundings. At times these robots even learn new behavior. They start out with a short routine and adapt this routine to be more successful at the task they perform.

• REMOTE CONTROL ROBOTS- Complicated tasks are still best performed by human

beings with real brainpower. A person can guide a robot by remote control.

• VIRTUAL ROBOTS- Virtual robots are just programs, building blocks of

software inside a computer. - A virtual robot can simulate a real robot or just perform

a repeating task. A special kind of robot is a robot that searches the world wide web.

• BEAM ROBOTS- Biology, Electronics, Aesthetics and Mechanics.- made by hobbyists. BEAM robots can be simple and

very suitable for starters