Beginners of robotics must get a good knowledge of any one family of micro controllers.Like
This 8051 microcontroller was first invented by Intel but later the 8051 core was given as freeware. So many manufacturing companies developed this 8051 with some extra features. Like AT89S51 from atmel and P89V51RD2 from Philips. Every engineering electronics student studies about 8051 microcontroller in their curriculum. But the problem with 8051 microcontroller is it will be a bit rigid as it will have a bit less features compared to other microcontrollers. You will need a separate programmer (dumper) to load the code into your controller.
If you are new to microcontrollers and started with basics better to get a over view of this microcontroller. Just get some theoretical knowledge of it. I will help to understand the terminology of microcontrollers.
THESE AVR CONTROLLERS ARE BEST PREFERRED FOR ROBOTICS PROJECTS.