Smart Car 2.0

This is the second model of my “Smart” Cars and this is much better than the first. This is also my entry into The Mindstorms Annual Online Competition under the Car category.


This car has 1 motor for driving, 1 motor for steering, and 1 motor for the ultrasonic sensor. The driving motor was geared 20:10:20 (so in the end – 1:1). the steering motor was geared 8:40 (1:5) for greater control in the steering, This did lower the speed at which it turned but it made it much more accurate and easier for parallel parking. The motor for the ultrasonic sensor was just holding the sensor with no gears, it was used many different was in different the programs.


(all programs require the HiTechnic Motor PID Block)

Parallel Park

In this program, the robot would find a parking spot and then parallel park. It put the ultrasonic sensor at a 90 degree angle with the car facing the wall, and it would drive straight. when it saw an open spot it would count the rotations of the driving motor till the end of the spot, if the motor rotated far enough  then it knew that the spot was big enough, if the spot wasn’t big enough, then it would keep driving. Then, once it had parked, it would wait for the orange button to be pressed and then pull out of the spot on its own.

You can download the program here.

Autonomous driving

This program would have the robot drive until it saw something (or the touch sensor got pressed), then back up, turn the heard to the left and the right, see which has more distance, then drive that way (if there was more than 20in of distance, if not it would back up and do it again)

You can download the program here.

Assisted drive

This program is remote controlled using the PSP-NX-v3. It is a normal remote control program using 1 joystick (up and down for forward and backwards and left and right for steering) but with one twist, when the ultrasonic sees something  it slows the drive motor down to half of normal to allow for greater control. the ultrasonic turns left and right with the steering so that it’s looking where the car is going. This was used in the last Smart Car also but there are a few improvements over that one, when going backwards the speed is not decreased, and when you click R1, it parallel parks.

You can download the program here.

Building instructions

Full building instructions can be downloaded here (PDF)

You can download the LDraw files here(.zip)

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