Control is the part of the robot which is dedicated to regulating and governing the actions of the robot according to real-life situations .

• The manipulator acts on the product which passes along the production line.

• The system of articulations moves the manipulator to the correct place.

There are 3 types of power systems:

• Electric power systems: are the most common way to power robots.

There are 3 types of the electric motors:

1. AC motor

2. DC motor

3. Step-by-step motor

AC and DC motors require constant control. The sensor must constantly give information, and the controller must constantly tell the motor if it should move or not.

Step-by-step motors don't require sensors for position control, they move a number of steps forward or backwards and the controller has a memory to remember how many steps they have moved.

Step-by-step motors don't have a lot of force, and they aren't energy efficient, so we use them for small applications where we need precise control of movement and position.

• Pneumatic power systems: use compressed air as energy.

  A compressor compresses the air into a tank.

  The compresed air travels from the tank through a system of pipes and valves to the cylinders.

  The compressed air moves a piston inside the cylinder, which moves an actuator.

• Hydraulic power systems: use the pressure in oil as energy.

  An oil pump adds pressure to the oil froma tank. The oil travels through a system of pipes.

  The oil moves the actuators and then returns to the tank.

Sensors pass the data to the processor as an electric signa.

There are different types of sensors for each physical parameter that can be measured. Let's look at some examples:

• Position sensors: Position sensors are linear or angular. We use them to measure the position of an object, its size or its shape. There are three types:

  -Inductive sensors: detect metallic objects without touching them. There are a small electromagnet.

  -Limit switches: are the simplest type of position sensors. If something presses they lever, they are on; if not, they are off.

  -LDRs: are resistances made of a semiconductor materia that varies its resistivity with variations of light. If an opaque object blocks the light, the LDR's resistance increases and no electricity flows.

• Force sensors: different kinds of force sensors detect different forces.

• Temperature sensors: are very common. Are also used as safety devices in machines which have a risk of overheating.

It also has a memory to store:

• The software

• Data, such as parameters for the program or information about the product.

Robots are generally used if they have one or more of the following advantages:

• More economical than a person

• Faster than a person

• Can work 24 hours a day

• Produce better quality

• Can work in dangerous places

In the first half of the 20ᵗʰ century, robots that worked with relays were first used. These automatisms were simple but functional.

Modern robotics started with the development of microchips in the second half of the 20ᵗʰ century.

Thanks to the microchips:

• Logic can be more complex.

• Robots are programmable; a programmer can change the logic (software) or the parameters.
  For example, if the programmer of a car painting robot wants to increase the speed at which
  the paint gun (manipulator) passes over the car, he/she only needs to change the “speed”
  parameter.

• Microchips are cheaper and more durable.

From “experience”, it knows that in the morning most people call the lift from the ground floor.

It also knows from “experience” that in the afternoon most people call the lift from the upper floors.

The microprocessor can decide that:

• In the morning, the lift will “wait” on the ground floor.

• In the afternoon, the lift will “wait” on the 5ᵗʰ floor.

1 mm = 1/1,000 m
1 nm = 1/1,000,000 m

The name “nano robots” refers to their very small size.

These robots have many potential applications, particularly in the field of medicine. Nano robots could, for example, travel along human veins and un-block a blocked vein.

They could also travel through the blood stream to a particular area of the body, and release a medicine there.