Here is another robotic arm that you can attach to your robot chassis to manipulate objects outdoors or inside. The Servosila Outdoor Robotic Arm can be mounted to the torso of your mobile robot and is powered by an on-board power supply system. It comes with intelligent servo drives. The robot arm is water-tight and dust-proof, so you can use the arm in snow or rain.
The Servosila Robotic Arm can be controlled using a Windows or Linux machine. It comes with a free ROS software package. You can use grippers to do more with it. The parts are easily replaceable.