24-07-2012, 03:44 PM
matlab controlled robotic car
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Introduction
'robot' an overview
There are many variations in definitions of what exactly is a robot. Therefore, it is sometimes difficult to compare number of robots in different countries. To try to provide a universally acceptable definition, the International Organisation for Standardisation gives a definition of robot in ISO 8373, which defines a robot as "an automatically controlled, reprogrammable, multipurpose, manipulator programmable in three or more axes, which may be either fixed in place or mobile for use in industrial automation
applications."
Matlab is the world's most recommended programming language for mathematical computations.
There are a plenty of control system designs in matlab for controlling robot. ascent has already developed a fuzzy neuro control system for a guided vehicle to operate in underground coal mines.
objectives
Matlab is the world's most recommended programming language for mathematical computations. It is very convenient to design complex control system for controlling robots in matlab. But in order to implement these control systems, the code has to be converted to c language to be burnt on to the microcontroller used in the robot. Many a times, if not always, the control system is too heavy in terms of memory consumption and process power requirement for a microcontroller system to work with. Hence it would be good idea if the control system is implemented in matlab in a pc and by establishing a duplex link between robot and the pc.
The objective of this project is to design a robot which can be controlled from matlab environment. The robot is to have two traction wheels and by varying the angular velocity of the wheels, the direction and speed of the robot can be controlled. A microcontroller take care of controlling these wheels. The microcontroller has also to be designed for receiving serial data through it's UART port. A function is to be developed in matlab which sends out four different codes to the robot, through its serial port. The four code words are stop, move forward, move right and move left.
Serial Port Communication
A serial port is a serial communication physical interface through which information transfers in or out one bit at a time. Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals and various peripherals. While such interfaces as Ethernet, FireWire, and USB all send data as a serial stream, the term "serial port" usually identifies hardware more or less compliant to the RS-232 standard, intended to interface with a modem or with a similar communication device.
connectors
While the RS-232 standard originally specified a 25-pin D-type connector, many designers of personal computers chose to implement only a subset of the full standard: they traded off compatibility with the standard against the use of less costly and more compact connectors (in particular the DE-9 version used by the original IBM PC-AT). Presence of a nine pin D-subminiature connector is neither necessary nor sufficient to indicate use of a serial port.
Some miniaturized electronics, particularly graphing calculators and to a lesser extent handheld amateur and two-way radio equipment, have serial ports using a jack plug connector, usually the smaller 2.5 or 3.5mm connectors and use the most basic 3-wire interface.
settings in serial communication
Many settings are required for serial connections used for asynchronous start-stop communication, to select speed, number of data bits per character, parity, and number of stop bits per character. In modern serial ports using a UART integrated circuit, all settings are usually software-controlled; hardware from the 1980s and earlier may require setting switches or jumpers on a circuit board. One of the simplifications made in such serial bus standards as Ethernet, FireWire, and USB is that many of those parameters have fixed values so that users can not and need not change the configuration; the speed is either fixed or automatically negotiated. Often if the settings are entered incorrectly the connection will not be dropped however any data sent will be received on the other end as nonsense.