What You See Is What You Avoid
The PC-BOT is capable of handling a wide range of peripherals and sensors, but it comes with two primary sensors. The first is divided into two groups of infrared (IR) range finders. The second is the USB web camera. Neither will do much without the appropriate software support, but the software has direct control over these peripherals.
The M3 system mentioned earlier is used to support the IR range finders. The first group is found around the bottom of the PC-BOT (Fig. 11). They are mounted on a semi-circular metal bracket and there are holes in the plastic cover for these sensors. The bracket and cover have room for 9 sensors. Five are included with the system. Additional sensors can be added as necessary. Coverage of the included five sensors is about the front 250 degrees depending upon the obstacle distance from the PC-BOT. Two of the sensors are for either side. One is aimed directly forward and the remaining pair is off to either side on the front.
A second metal bracket and sensors can be added, but comparable coverage could be obtained with just three additional sensors mirroring the ones in front, since the side sensors would overlap.
The second set of IR sensors is found in the middle of the robot on the front (Fig. 12). These sensors are aimed at the floor at an angle. These are designed to detect the general height of objects, but more importantly they can be used to detect the floor or, more importantly, the lack thereof. A 50-pound hunk of metal and plastic falling down the stairs or rolling over the side of a ledge is not an image most robotocists will want to see. The PC-BOT is rugged...but it isn't indestructible.
The other sensor is the Logitech web camera that is mounted on top and to one side of the PC-BOT (Fig. 13). The ball camera can be aimed in any direction, but typically, "level and forward" will be the direction for most applications. The camera does not pan or tilt, but an adept designer can add this feature. Aimed forward, the camera provides full coverage of the width of the PC-BOT after about two feet.
The camera is suitable for obstacle detection and object identification. Likewise, the processing platform has sufficient horsepower to handle the software that can make it happen. Of course, adding and managing this type of software is a major hurdle, but that is for another article.
Headless Operation
A standard Linksys USB-based 802.11g adapter provides a wireless link to the PC-BOT. This will definitely be the way the PC-BOT is programmed and controlled. It has sufficient bandwidth to handle streaming audio and video from the PC-BOT while providing enough headroom for control going in the other direction if necessary. Standard remote control programs like VNC will likely be used to track and control the system, although custom applications can also be used.
The lack of a microphone is the only thing I found missing in the basic PC-BOT architecture, although it is a trivial addition. The motherboard does have an audio input, so it is just a matter of adding the cabling. There are plenty of places to hide it.
One feature I would like to see would be a control panel and input buttons, but this is easy to add even without making major modifications to the plastic cover. There is a removable panel on the top in the rear that is just the right size for such a small control. While the current panel snaps in place, it is not too hard to modify this with a hinge to allow it to flip up; but again, that's another project.
It took a while to get through all of the PC-BOT's hardware features, and it will be even longer to get through the software side because of the flexibility of this platform. I'll be using this to examine robotic software such as Microsoft's Robotics Studio in future articles. The PC-BOT will support almost any PC-based software so there will be a number of articles about the PC-BOT in the near future.
The PC-BOT comes with some sample applications and support for platforms like the Robotics Studio. We had the PC-BOT dancing and chasing the cat as soon as the batteries where charged. Our poor kitty was terrorized as my daughter had the PC-BOT wandering around, saying "Here kitty, kitty...." Now I need to get it ready to be a presenter at our local science fair.
For more info, chec out Mini-Box, Microsoft, and White Box Robotics.