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TWO DIFFERENT TYPES OF PROGRAMMING
There are two main methods of controlling a robot, the first method is using feedback which is called Closed-Loop
Control and the other method is called Open-Loop Control, in which case robots incorporate no feedback, therefore,
they depend instead on mechanical stops to control movement. This method is used to carry out simple instructions
accurately, since most robots only do a specific job, such as screwing in a few screws, they only need to know the
boundary of their specific area. While other sophisticated robots rely on feedback in the form of continuous data.
These robots are being made to resemble human decision-making techniques, some of which are still in the
developmental stages. The data (feedback) can come from a variety of different devices such a vision systems,
tractile sensors or in terms of industrial use, devices that detect the positions and the rate of movement of the
robot's joints.
However, there are still simple robots that use the Closed-Loop Method. An example of this would be a household
thermostat. It is a device that senses the environment and has a mechanism that reacts to the environmental change.
In this case a bimetallic strip changes shape in reaction to temperature change and thereby turning on the heating
or cooling unit. The diagram in Figure 1 illustrates the closed-loop method and can be used to display the workings
of a thermostat. First the controller is programmed to the desirable temperature, this information is then sent to
the mechanism which in this case is the thermostat. The device then responds with a physical action which modifies
its external or internal environment. Next, sensors detect and measure the modification, then returns the results
to the controller, which then calculates the difference between the actual and desired results and closes the loop
by issuing a corrective command to the mechanism.
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