The JoyRider! . Step into the future with the JoyRider! Designed to have lots of fun! It makes wheelies and more. NXT technology is used to control this race machine. .
Press release, 28 June 2068.
Nowadays people spend most of their time in the virtual world to work, learn and socialize. Transportation of goods is by air ships that travel autonomous. Cars that use roads to drive are no longer needed. Nevertheless the Vuurzoon company proudly presents a brand new car: "The JoyRider!". A car designed for one reason only: To enjoy!
You can drive the JoyRider yourselves or you can choose to be driven fully automatically. It's devastating fast and can make extremely sharp corners. Moreover, with the JoyRider you can join inline race competitions. During these races your race car will follow autonomous the line at the racetrack as fast as possible. The JoyRider enables you to perform exciting actions like a Wheely, a Spin and a so called ZigZag. To cool down a little after all these G-forces, you can cruise around in your JoyRider while listening to fantastic Mindstorms music. Meanwhile, special light effects will flash at the beat of the music. Enjoy the ride!
The JoyRider is equipped with an 8-Star fusion generator to charge the power capacitor. Electric drives are applied for the left and right traction wheels. The construction is well balanced and has a slide able nose wheel to enable smooth steering and special actions like wheelies (large photo) and spins.
The JoyRider has a characteristic lime green Hero design. To enter the cockpit the roof opens up and steps turn up (left photo). The comfortable duo cockpit includes two vehicle control units (right).
Light effects are created by the fusion generator (left photo), the touch-down LED (large photo) and the ground light (right photo).
Lego Mindstorms NXT technology is applied to drive and control the JoyRider. In total 7 sensors are used:
1) IR Receiver sensor: The infrared receiver (HiTechnic nr NIR1032) enables control of the vehicle by the driver, using a Remote Control (RC). Three different channels are used to control all functions:
a) Channel 1 to control the left & right drive motors in the manual mode
b) Channel 2 to select the drive mode
c) Channel 3 to select special actions.
2) Color sensor: This sensor (Lego nr. 9694) is used in a multi functional way:
a) The color sensing mode is used to search for race track lines. It only stops when a black track line is spotted. Other line colors are neglected.
b) In order to actually follow the black track line, the sensor switches over to the light intensity sensing mode. This allows the use of a proportional control algorithm, which improves vehicle speed and accuracy.
c) The same sensor is also applied as ground light. All three colors are used depending on the selected drive mode. In music mode, it turns into a tree colored disco light which flashes at the beat of the music as shown in the video.
3) Three different sensor types are used to drive autonomous:
a) Ultrasonic sensor: Used to avoid impact with objects in front of the vehicle.
b) Mindstorms Touch sensor: The touch sensor is actuated when the front bumper hits an object which will put the vehicle in reverse gear.
c) Motor Position sensors: When the vehicle is stuck into an object, this is recognized by the position sensors that don’t observe any movement, although power is transferred to the wheels. The vehicle responds to select another escape route.
4) Touch sensor as integrated in the Power functions Light up brick: Used to signal a successful wheely, which includes a touch-down of the vehicle back side, as shown in the second photo from the top and in the video.
The JoyRider is programmed with NXT-G software. The main program refers to 9 subroutines which are implemented in “MyBlocks”. The main program can be downloaded, see link JoyRider program. The following 8 modes are implemented:
1) Manual drive mode as controlled by the RC (different drive speeds possible). The Manual mode can be used in all other modes for emergency actions, to prevent a crash.
2) Automatic mode to drive autonomous. A random generator is used to get variable drive speeds and different turn directions (left or right). Action modes and music are performed randomly.
3) Track mode to follow a track line. A proportional line follow algorithm with automatic sensor calibration is applied. The implemented subroutine is based on the great program “SmoothFollow” of Dave Parker, which can be downloaded with the following link nxtprograms.com.
4) All mode, to combine all other 7 modes. Several random generators and timers are used to secure that every ride is unique.
5) Wheely action mode. Performs a wheely as long as no objects block the drive way.
6) Zigzag action mode. Performs a sequence of fast corners as long as no objects block the drive way.
7) Spin action mode. First the environment is scanned for dangerous objects. Secondly several spins are performed, if possible.
8) Music mode. Plays Mindstorms music with light effects.
The active mode is displayed on the LCD screen as shown on the right photo above.
The JoyRider is build with parts from Lego Mindstorms NXT (set nr 8547). However many other parts are used, including:
1) Fiber optics driven by micromotor, see Lego Technic Space Shuttle set nr 8480
2) IR receiver from HiTechnic part nr NIR1032
3) Power functions Light up brick from Lego Creator Ferocious Creatures set nr 5868
4) Flexible & thin custom made NXT cables, for instance by Mindsensors
5) Lime green arrow bricks from Lego Hero Factory Corroder set nr 7156
6) Lime green panels with Artwork stickers from Lego Technic Dirt Bike set nr 8291
7) Large wheels from Lego Technic Motorbike set nr 8051
8) Action figures from Lego Technic Rescue motorbike set nr 8255
Enjoy the ride!