Here is a 4WD Tactical Robot that can be remote controlled via a tablet over WiFi. It has a rugged design with motors that enable it to climb hills and curbs. The robot has a camera with 27x zoom, 360-degree pan, and -10, +50 degrees of tilt.
This ATR has a max payload capacity of 25lbs. With video and 2-way audio, you can clear rooms remotely. The battery lasts up to 4.5 hours, depending on how you use the robot.