ROBOTMAK3RS Blog

( Direct link ) This robot is from chapter 9 of the One-Kit Wonders book . If you watch the video, the robot may appear to be very simple. There are however, two things that make GrabBot special. One of these two is the grabbing hand. Using one motor, it grabs and lifts object, which is a cellphone in this case. The other is its autonomous behaviour. When I trigger the program to start by saying: "Get my cellphone", it starts searching for the closest object in range. While spinning around, it continously stores a sensor value along with a location in two variables. Then, it returns to the position where it measured the lowest sensor value and grabs the object. When doing so many redaings from the Ultrasonic Sensor, it functions relatively accurate. It still has a few problems detecting balls, but if they're not too far away, it does find them. P.S. Book reader Enrique has posted a call to action for One-Kit Wonders readers. Read it here .

One of the first robots I tried to make without instructions, back in the RIS days, was an all-terrain autonomous rover. These robots are nice in that they don't have to be too hard to build or program, but they can have many challenges and thinking problems to overcome, and they can stimulate many creative ideas and designs. Although an all-terrain rover should technically be able to traverse any terrain, we're talking about NXT robots, so you might want to limit yourself to inside your house. Since your robot needs to move around without you controlling it, you'll need to give it the capability to detect and respond to (or not be affected by) potentially problematic situations. Aside from the obvious one of walls and other simple obstacles, these may include: - Steep dropoffs - Short overhangs: sometimes a ledge or other object may block the top of your robot instead of the bottom. In this situation, a mechanism for detecting obstacles soley on the ground level would no...

For the final project in the Advanced Robotics Club that I teach at our local middle school, I made up a challenge called SARB: Semi-Autonomous Robot Battle, which is an extension of Sumo-like challenges. Although we used RCX kits (because we have a bunch), it could just as easily be done with the NXT, so I will explain it here and reference several NXT projects on nxtprograms.com that you could use to get started with a challenge like this using the NXT. For the fighting ring, (er, ahem, "Playing Surface"), I used our FLL table, turned the mat upside down, and then used electrical tape to mark out an elongated octagon-shaped ring. Like Sumo, one of the goals is to push the other robot outside of the ring. However, the SARB robots can also have some kind of striking (motorized) weapon and get points for successful strikes on the other robot. Like a Karate match, only a "controlled strike" will count as a point. Random spinning/flailing weapons that happen to ...