Robots are finding daily use, but much more can be done only if we have developers familiar with the technology. Products like iRobot's Roomba are available in local stores. On Mars, NASA's twin rovers, Spirit and Opportunity, continue to explore the planet.
Robots have garnered the interest of teachers and students alike. They seem to multiply in colleges. One reason is the increased number of robotic platforms that are becoming available. In this first article of the Real Robots series we examine Lego's Mindstorm NXT (Fig. 1), iRobot's Create (Fig. 2) and White Box Robotics' PC-BOT (Fig. 3) from a hardware perspective. The next article will take a closer look at the software that comes with that hardware. The series will continue with more hardware and software reviews.
These new robotic platforms are a change from earlier platforms like Parallax's BoeBot (EiED Online>> RoboNexus And ARM Conferences, ED Online #11306). The BoeBot and similar platforms were designed to be used to impart knowledge in electronics as well as robotics. While it is possible, and even probable in advanced environments, to use these new robot platforms for the same purpose, they will more likely be used to concentrate on the software aspects of robotics. The more sophisticated classes will likely add custom hardware requiring electronics expertise, but the majority will use standard modules to augment these platforms.
Of course, having popular, standard platforms like these new robots opens new opportunities for third party vendors. There is already support for iRobot's Roomba from companies like Spark Fun.
Different Platforms, Different Purposes
For a detailed review of the hardware, take a look at the individual reviews. In the meantime, we take a look at why and how these different products address different markets.
Lego's Mindstorm NXT is obviously targeted at the younger crowd, but its ARM-based control module and peripherals put this package a step above Lego's prior robotic incarnation. It is based on Lego blocks, but there are a plethora of custom blocks for the NXT. They are general enough to address a wide range of designs, but compatible so that rather sophisticated robots can be constructed from combined kits.
One of the big differences between the NXT and the Create and PC-BOT is that the NXT is designed for robots to be built and rebuilt often within hours of each other. It is great for experimentation and for learning about mechanical engineering as well as programming. It is possible to do some electrical work but this typically requires additional hardware, not just a few more Lego blocks.
The NXT is an excellent learning platform. While Lego models can be made rather sturdy, they don't compare to the rigid structures of the Create or PC-BOT.
Then there is iRobot's Create, based on the Roomba. They share quite a bit of hardware, but there are significant differences. iRobot opened up the Roomba to programmers, but you can't make much more out of it than a programmable Roomba. This is where the Create comes in.
The Create is designed to be an expandable platform, but the core robotic behavior remains intact. Where the NXT builds upon Lego blocks, Create designers have screw mounts, cargo bays and fixed resources to build on. The Create is really a multiprocessor system.
The Create's main processor is the same as the Roomba. It can run simple scripts and its behaviors can be controlled by another processor. Out of the box, the Create has only the main processor, but any work will likely include adding at least one more processor, like the 8-bit Atmel AVR in iRobot's Command Module.
The Create inherits the Roomba's navigation capabilities, and alleviates the need for the programmer to perform those low level chores. The Create has the potential to be a platform for more sophisticated processors, making it a better target for developers looking to create more advanced robots.
White Box Robotics' PC-BOT is for heavy duty research, literally. Compared to the other two platforms, the PC-BOT weighs a ton. Well, not quite...but it is not something you want to pickup repeatedly.
Like the NXT, the PC-BOT has a single processor for handling computational chores. Of course, the PC-BOT has a much more powerful processor. In fact, it can house any Mini-ITX motherboard.
Cost is a major factor when choosing between these platforms. The NXT and Create are a couple hundred dollars while the PC-BOT is an order of magnitude higher; though, of course, it is more powerful by an order of magnitude as well. Its drive train and battery are significantly heftier. The amount of processing power and the number of peripherals that can be brought to bear for a particular problem are also significant.
The other key difference between these platforms and older ones is the quality of the software. But that's another part of the story.