I am making a mobile robot with a metallic chassis. Usually, a non-moving appliance will have the ground pin of the wall socket connected to the chassis, but in a moving device, there is only the virtual ground, AKA the minus side of the battery. Thus I conclude that that should be connected to the chassis. In what instance would that be inadvisable?
(Side note: my system doesn't have separate logic ground and power ground, so that shouldn't be a concern. Also, if that is in any way relevant, I am also using the chassis as a heat sink.)