Doraemon the Movie: Nobita and the Steel Troops: The New Age 2-06

In a distant galaxy, a robot society plans to invade Earth and take humans as their slaves. A robot named Riruru is sent ahead as a scout who will make the necessary arrangements for the invasion to occur. Luckily for human race, Nobita accidentally interrupts this reconaissance mission. Nobita and his friends will then need to somehow face an entire army of steel troops and stop the mechanized offensive.