Falcon – Remote Control Race Car

So far, we have made a few robots that used tank-style steering, and one walking bipedal robot. In this chapter, we will be doing something completely new: we are going to build the Falcon, a remote control car! The steering method for the Falcon, conveniently referred to as car steering, is different from anything we have seen so far. We will also learn about the car-style drivetrain and relate it to the mechanisms used by cars in the real world. We will specifically look at how the Falcon's drivetrain gives it the speed and agility of a race car.

It may seem strange to include a remote control car in a book about smart robots. A smart robot must, by definition, make decisions about the environment and react accordingly. So, if a human controls the robot with a remote, how can this robot be considered smart? You will soon see that...

Technical requirements

You must have EV3 Home Edition Software V1.2.2 or newer installed on your computer. You may also install LEGO Digital Designer (LDD) V4.3 and download the LDD file for this project to guide you in the building process.

The LDD file is available on the Downloads page of the the Builderdude35 website:

http://builderdude35.com/download/falcon-ldd/

The LDD and EV3 files for this chapter are available on GitHub:

https://github.com/PacktPublishing/Building-Smart-LEGO-MINDSTORMS-EV3-Robots/tree/master/Chapter06

Check out this video to see the robot in action:

https://goo.gl/9FL3HL

Mechanical design

The Falcon features a unique mechanical design that is similar to the designs used by some cars in the real world. This smart hardware makes the Falcon's driving fast and smooth.

The drivetrain and steering in the Falcon are completely different from anything that we have discussed in this book thus far. In the previous chapters, we made robots that used tank-style driving, where two EV3 large motors powered the robot. In these systems, each large motor was dedicated to the wheels or tracks on one side of the robot. This system used direct drive, meaning that the drive motor was directly connected to the wheel/track without any gears or other mechanisms in between. The robot steered by varying the power split between the two motors.

The Falcon changes all of this. In fact, the only similarity that the Falcon's drivetrain shares with those previous robots...

Programming

Although the Falcon is remotely controlled by the user via a remote control, its RC program is quite intelligent because it coordinates the complex actions and decision making behind the scenes, resulting in a smooth and user-friendly program.

Control scheme

We should establish what each of the buttons on the EV3 remote will do. Earlier, we said that the driving and steering functions are independent of one another. We will program the controls accordingly: the left (red) side of the controller will control the driving, where up is forward and down is reverse; the right (blue) side will control the steering, where the up button will steer the Falcon's wheels to the right and the down button will steer them...

Summary

In this chapter, we took our project in a completely new direction and broke away from tank-style driving to make a purpose-built speed machine. While building the Falcon, we learned about some of the mechanical components used to make a car-style drivetrain, such as the differential. We reapplied the rack-and-pinion mechanism to use it for steering. We discussed how each of the mechanical features in the Falcon relates to the design of cars in the real world.

We extensively used the rotation sensor built into the EV3 motors to coordinate an intelligent steering system. We also learned how to make MyBlocks and saw the advantages they bring when they are used in a program. We applied knowledge acquired in previous chapters to make a car-style remote control program. Finally, we resolved the paradox of a smart remote control car: even though the user controls the Falcon...