D. Visual Feedback and Remote Control
A USB camera is used to provide video information for the
robot. The visual feedback information can help the user to
observe the home environment, the position of the robot, and
the posture of the manipulator. Users can control the robot to
swap batteries between the robot and the charging station. The
remote control terminals such as PC and PDA connect with
the home server through the Internet. The robot connects with
the home server through the Wi-Fi network. When the voltage
of the Li-ion battery is lower than a preset threshold, the robot
will send an alarm message to the user. The user can send
moving commands to the robot to swap batteries.