iBOTZ MR-1005 Tribotz

Tribotz Overview

The iBOTZ Tribotz is a great introductory robot kit that performs three basic robotic functions: line-following, sound sensing, and obstacle avoidance. In line-following mode, the Tribotz follows a black line on a white surface using a pair of phototransistors and a bright LED. In sound-sensing mode, the Tribotz drives forward until it detects a loud sound, in response to which it makes a quick turn backwards before resuming driving forward. In obstacle-avoidance mode, the Tribotz operates basically in the same way as in sound-sensing mode, except that an infrared reflectance sensor is used instead of a microphone.

The Tribotz is powered by two preassembled gearboxes that provide a smooth, quiet drive system, and which make quick work of putting the Tribotz together. By assembling the Tribotz robot kit, you will learn about how autonomous robots can "see" obstacles and black lines and "hear" sounds, and you will practice basic skills that are applicable to assembling any electronics or robotics kit. Playing and experimenting with the Tribotz will give you an appreciation for what it takes to create an autonomous robot.

Kit Contents and Packaging

The Tribotz kit comes in a sturdy, colorful box with English text. The kit includes all the parts you need to put it together, including three pre-soldered circuit boards, two DC gearmotors, and high-quality, durable plastic parts that snap and screw together nicely. The kit has relatively few components, primarily due to the simplicity of the design and the preassembled gearboxes.

The gearmotors are very similar to the Solarbotics GM2 gearmotor, but they have smaller output shafts that protrude on only one side. Unlike other iBOTZ kits, the motor leads have wires soldered on to them.

The smaller parts, including the gearmotors and printed circuit boards, come packaged in a separate plastic tray. Small hardware is limited to two kinds of screws, making parts identification very simple. A 34" x 34" folded paper with a printed track for line following completes the package.

Assembling the Tribotz

Due to the pre-assembled circuit boards and gearboxes, assembly is very simple and quick. All parts fit together well, and all you will need are a small phillips screwdriver, though wire cutters may be helpful in removing some of the pastic parts from the parts trees.

The instructions are very easy to follow, although the drawings of the two screws in the parts list are misleading. Just remember that the three smaller screws are for mounting the wheels and for securing the battery hatch; the larger "screw B" is used everywhere else.

Important Note: step 7 on page 15 instructs you to install batteries prior to attaching the battery holder leads to the printed circuit board. Doing so would expose your batteries to a potential short circuit that would destroy your batteries. We recommend that you do not install the batteries until your robot is assembled.

The instruction manual contains a brief history of robotics milestones as well as a relatively detailed description of the theory of operation of the robot, including a complete schematic diagram, block diagram, and block-by-block descriptions. The descriptions are among the most detailed we have seen, but they are still difficult to follow for the robotics or electronics novice. Fortunately, you do not need to understand everything to make the robot work!

Letting it Loose!

Like most small robots with small wheels, the Tribotz performs best on smooth surfaces, though we saw decent performance on a carpet as well. The obstacle sensor and line sensor both use a very bright red LED instead of an infrared LED, providing the user with a bit more appreciation for the inner workings of the robot. The obstacle sensor is very effective: we saw detection of typical (not especially shiny) objects up to six inches away. The sound sensor also worked without a hitch.

The included track for line following made it easy to get started with that mode, and though the robot often lost the line at first, slight tweaking of the reflectance sensors gave us much more solid performance (we did not add the glue in the picture to the right). The Tribotz, having two sensors for line following, performs better than other line-following robots that have just one sensor.

The iBOTZ Tribotz is a good robot kit for anyone as young as 10 who wants to get into robotics. We have not seen a robot kit that is easier to assemble, and you get all of the functions that are commonly available on beginner-level kits, all in one robot. We especially like the kit for its use of high-quality, pre-assembled gearmotors that provide smooth and quiet performance. Coupled with the spacious chassis, the motors make this kit a prime candidate for future retrofitting with your own electronics. Through construction of the robot, you will gain valuable skills that will help you with more advanced projects in the future.

Note: The iBOTZ Tribotz is a kit; assembly is required. Two AA alkaline batteries and one 9-volt battery are required but not included.

h2. iBOTZ MR-1005 Tribotz Specifications Features: –Line following (2 phototransistors, 1 LED) –Sound sensing (microphone) –Obstacle avoiding (IR reflectance sensor) Actuators: Two DC motors in preassembled gearboxes Power supply: –2 AA alkaline batteries for motors –1 nine-volt battery for electronics (batteries not included) Dimensions: 145×150 x 110 mm (L x W x H)