I travel for work but have pet

I travel for work but have pets. I have a pet sitter that comes once a day while I'm away but if something happens right after she leaves it could be 24 hours before anything is done about it. I'd like a robot that could keep tabs on them by having the ability to find them (tracker attached to collar) and check on them when I request it. Robot could also give them food and water if need be by triggering and automatic dispenser. As I am gone for days at a time the robot would need a way of self charging, like a roomba, when its battery is low.