The change of the location and movement speed of swing fountains is an important factor for the generation of swing water style natural and unrestrained wind color. The position sensor of fountain swing mechanism should be waterproof and non-contact positioning device. Hall sensors induced by magnets, photoelectric sensors guided by optical fibers or rotary position encoders attracted by magnets are often used. For example, the positioning device for fountain swing mechanism using position encoder includes: position encoder installed on swing motor shaft, high-speed counter, control computer, communication interface, etc. As the connecting rod of the swing mechanism usually has a large gap, in order to achieve positioning, the swing mechanism can only reach the positioning point from one direction, so as to make its repetition accuracy. Therefore, when the rocking mechanism needs to stop, it must reach the positioning point from one direction at a time.

The positioning accuracy of swing mechanism is affected by motion moment and resistance moment. The motion torque is determined by the power supply voltage of the motor and the motion speed before stopping, while the resistance torque is composed of friction force of the swing mechanism, the speed of water flow, the surrounding wind force, etc. Obviously, these are all factors that cannot be determined in advance. Therefore, in order to achieve the goal of positioning, we need to change its control parameters every time. There are generally two control parameters for positioning by motor energy consumption braking, i.e. the magnitude of DC braking current and the starting braking time. The more convenient way to control the computer is to change the braking time. All kinds of swaying in the music fountain can make people feel the flexible beauty of the fountain. The swaying fountain is produced because of the swaying mechanism under the water surface, which makes the waterscape beautiful and pleasing to the eye, gives people a magical feeling, and is a manifestation of the high-tech development of the times.