Basic Elements of Robotics System

The basic element of a robot is given as under below:

1. Mechanical platform- the hardware base
2. Sensors
3. Motors
4. Driving mechanisms
5. Power supplies
6. Electronic controls
7. Microcontroller systems
8. Languages
9. R/C Servos
10. Pneumatics
11. Driving high-current loads from logic controllers

Mechanical platform- the hardware base: such as a wheeled platform, arm, or other construction, capable of interacting with its environment.

Sensors: Sensors are the parts that sense and can detect objects or things like heat and light and convert the object information into symbols or in analog or digital form and then robot reacts according to the information provided by the sensory system. The sensors used in robotics are

• Vision Sensors: Camera, Frame Grabber, Image processing unit
• Proximity Sensors: distance is estimated between the robot and the object.
• Proprioceptive Sensors: are responsible for monitoring self maintenance and controlling internal status. This includes battery monitoring, current sensing, and heat monitoring.
• Logical Sensors

Motors: A variety of electric motors provide power to robots, making them move with various programmed motions. AC /DC motors can be used.

Driving Mechanisms: Gears and Chains, Pulleys and Belts, Gearboxes are used to transmit rotational motion from one place to another

Servomotors: They adjust themselves until they match the signal. A very common use of servos is in Radio Controlled models (R/C Servos).

Power Supply: Power supply is provided by two types of sources:

• Batteries that are used once only and then discarded; and
• Rechargeable batteries: that operate from a reversible chemical reaction and can be recharged thousand times.

Electronic controls: This uses a digital logic control circuit which controls the mechanical system. This circuit is connected to the mechanical system through a bridge-relay. A control signal generates a magnetic field in the relay's coil that mechanically closes a switch.

Microcontroller systems: Microcontrollers are intelligent electronic devices that are used inside robots. They deliver functions similar to those performed by a microprocessor (CPU) inside a personal computer. It comprises

• Speed: is designated in clock cycles, and is usually measured in millions of cycles per second (Megahertz, MHz).
• Size: specifies the number of bits of information the Microcontroller can process in one step (for example, 4-, 8-, 16-, and 32-bits).
• Memory: Microcontrollers count most of their read-only memory (ROM) in thousands of bytes (kB) and random access memory (RAM) in single bytes.

Languages: the following programming languages are used:

• VAL (Variable Assembly Language):it is the first language used in programming.
• Robo ML (Robotic Mark-up Language)
• ROBOFORTH
• ROSSUM
• XRCL (Extensible Robot Control Language)
• Scripting language such as RoboLogics
• Visual Programming Languages is written by Labview

Pneumatics: Pneumatic system is used for actuating purposes.Pneumatics are useful for generating linear motion.

Driving high-current loads from logic controllers: One of the most common tasks in designing and building robots is the interfacing of logic circuitry to high current loads such as motors, solenoids, or Nitinol wire. Logic circuitry can sink and source loads in the range of 1 to 20 mA. The logic circuitry are

• Switch basics: interface for high-current loads can be though of as a switch.
• Relays: One of the simplest ways to accomplish high-current.
• Transistors: an semiconductor version of a relay.
• H-Bridges: Most loads such as motors need to be operated in both forward and reverse. This requirement often leads to a circuit layout known as an H-Bridge.