Why did the control robot resist the captain in the robot story? Why do a group of robots chase the protagonist first and then help them? ...

There is more and more garbage on the earth, and finally it becomes a garbage planet. Someone built a space station in space and immigrated all human beings there. People there open their mouths to eat and drink like newborn babies every day. They all have robots to do it for them. There are only robots left on the earth to clean up garbage. The protagonist is an old robot cleaning up garbage. The stationmaster of the space station was ordered to send robots to the earth regularly in search of life and green plants. If you look for them, when they come, they will lead mankind back to the earth (but this is a conspiracy. They want to leave humans on the space station forever. Later, a robot went to the earth, found a plant and fell in love with Kawara Tsutomu. Later, he brought the plants back to the space station. The stationmaster also missed the earth and wanted to lead humans back to the earth, but the robot was controlled by the boss, and he opposed it if he wanted to stop it ... Finally, humans returned to the earth ... They were all tired of typing by hand. I hope to give my best thanks.