The call button system facilitates customer requests for robot assistance by pressing a button. It consists of three components: the call button, receiver, and optional bridge. 

Customers initiate a request by pressing the call button, which sends a signal to the receiver. The receiver interprets the signal as a request and triggers the necessary actions to summon the robot.  Upon receiving the request, the robot navigates to the predetermined target point and interacts with the customer or provides the required service.