* Added speed limitation of the robot
* Removed leading underscores for global vars
* Added unit test for robot speed limitation
* Modified x/abs(x) to np.sign(x); fixed code style
* Removed 'random' from test func header comment
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up
* Test code clean up