Mario's Lego Robotics Archive

Cinque

Cinque (pron. chee-n-koo-eh) in Italian means "five". I chose this name because this robot was inspired to Johnny Five from the Short Circuit movie (one of my kids' favourite).

Cinque was designed to be easily configurable and to perform different tasks. He is currently programmed for three basic behaviours:

1) Obstacles avoidance and path finding. For this task Cinque uses the ultrasonic distance sensor (by John Barnes) placed in his head. When he detects an obstacle he rotates his head to find the best path, then turns accordingly.
The same ultrasonic sensor also triggers requests for hand usage: when Cinque detects that the distance reading reduced a lot in a very short time, he deducts somebody put an hand in front of him. So he changes the state of his hand from open to close or vice versa to grab/drop small objects.

2) Line/wall/hand following. Using a proximity sensor (by Techno Stuff) Cinque can easily follow a wall or a human hand. The same input port can be switched to a light sensor to turn Cinque into a line follower. The algorithm is the same for all the following functions: it runs a short calibration sequence and find appropriate min, max and hysteresis values.

3) How could a Johnny Five styled robot miss a dancing feature? In this mode Cinque plays the Saturday Night Fever theme while moving tracks, arms and head in a random but rhythmic way. Thanks to Guido Truffelli for his MIDI2RCX program that converts MIDI files to NQC (or legOS) code.

This diagram shows the connections among the RCXs and the different subsystems.

RCX2 (master) and RCX1 (slave) communicate throught their IR ports. RCX2 runs the main program and control RCX1, which simply execute the required tasks. The communication flows only from RCX2 to RCX1.

In the diagram you can see four hardware subsystems: head, motion, following and hand/arms. The head can rotate right or left, and its motion is controlled by RCX2 through the motor M3 and the rotation sensor R1. On the head there is an ultrasonic distance sensor U1 used to detect obstacles.
Motion is provided by two large tracks controlled by motors M1 & M2. Stability is ensured by a back pivoting wheel.
The arms can swing up and down using motor M5 (when left one goes down right one goes up and vice versa). The right arm features a mechanical hand that can grab/drop small objects. This hand is controlled by M4 through a very long flex cable.
The system in charge to follow things can be configured to use a proximity sensor (P1) or a light sensor (P2).

Front view. I made any effort to keep Cinque as compact as possible. The structure has been redisigned many times to host 2 RCX and 5 motors without being too large. An other important goal I had in mind was the RCXs had to be easy to remove, to change batteries and also to reuse them for other projects without damaging Cinque.

Right side. You can notice the levers that make the arms swing. And the flex cable coming from inside to control the right hand.

Close up of the right arm. The 24t and 8t gears behind the flex cable aren't related to the arm, they are part of the gearing that rotates the head.

The hand in detail. The rubbers provide a gentle and adaptable move of the fingers.

To see where the flex cable goes it's we have to remove RCX1 (the front one). The cable is connected to a gearbox and...

...this through a belt to the motor M4 that's located at the very bottom of the robot, close to the pivoting wheel.

The head is rotated by M3 through a double group of pulleys/belts on the left side, a long axle that engage rotation sensor R1 and goes the right side, and a further reduction stage with 1:3 ratio.

In the bottom left corner of the picture you can see the small IR reflector (two 2x2 white tiles). When Cinque was almost finished I realized the two RCX had problems with the IR comm. I tried and added that small reflector and everything went fine.

Close up of the tracks. M1 and M2 supply motion through two 40t gear in each track. The 40t gears are connected to the motors using (not visible) 8t gears.

Cinque shows hand following during an exhibition in Milan (photo courtesy Stefano Gatti).

This small, yellow robot, S23, was a preliminary study for Cinque.

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