RoboCam is a web-based telepresence camera platform built on the iRobot Create and the Parallax Propeller chip. Using a web browser, RoboCam can be remotely controlled from any location that has internet access. A simple set of web controls and a live video feed allow you to drive RoboCam around as though you were actually there. When you’re done exploring you simply drive back to within the vicinity of the recharging station and press Dock. Using the built-in docking capability, the Create will automatically maneuver and dock itself. Once the Create has docked the station it will recharge completely depleted batteries in less than three hours. In order for the user to keep an eye on the RoboCam’s health the robot continually sends back telemetry. This includes battery capacity, temperature, voltage, and current drain which are displayed in the web browser.
The Create provides all the necessary sensors and docking/charging capabilities. It uses the built-in cliff and bumper sensors to protect itself from falling down stairs and avoiding objects. For distance measuring a Ping is used. This complemented the Create’s own sensors and provided a less violent method of detecting objects as opposed to the way the Create does it by crashing into it first and then sensing it with a bumper switch.
Most of RoboCam’s components are mounted in or on a 10 x 8 electronics case mounted onto the Create’s four hard points located around the cargo bay. It is mounted slightly forward to keep the Create’s center of gravity over its main driving wheels. Two voltage regulators were used to reduce the Create’s 14.4 volt battery down to 12 volts for the camera and 9 volts for the electronics.
RoboCam uses an off the shelf Panasonic Wireless Network Camera (BL-C30A) for video. This keeps the design simple and eliminates the need to get into complex streaming video. Optionally audio could be included by selecting a more advanced (and more expensive) model. The camera is mounted on top of a 2 foot length of PVC pipe. This puts the camera about 36 inches above the floor which is the optimal height for driving as well as checking out your surroundings. As an added bonus, the camera’s built-in pan and scan allow you to look from the floor to the ceiling and nearly 180 degrees from left to right.
To establish the connection between the RoboCam and the Internet a separate web server using the PINK (Parallax Internet Netburner Kit) is used. Using a Parallax Propeller chip, commands from the remote web user are received by the PINK and are then transmitted to the RoboCam using a pair of Parallax 912 MHz wireless transceivers.
You can view a demo of the RoboCam user interface below. This video shows RoboCam being controlled by a web browser. The small red dot that is always present in the lower part of the video picture is projected by a laser that is aimed three feet in front of the robot. It assists in steering and provides depth perception. RoboCam will protect itself from crashing and falling down stairs by using its sensors. If a hazard is detected, RoboCam will override the remote user and take the appropriate action to prevent damage to itself and property.
You can also read about a simpler version of this telepresence technology used in a robot called Romey (Part 2) in the next issue of Robot Magazine due out on April 22nd.