Fountain is a combination with a specific shape that sprays water or other liquid through a nozzle under a certain pressure. Nowadays, music fountains are generally artificial landscape fountains relying on fountain equipment. Mainly through the control of frequency converter to achieve rhythm and rhythm, the water in the music fountain is rich in changes, which gives people a real and intuitive aesthetic feeling with the lighting. Various swings in the musical fountain can make people feel the flexible beauty of the fountain. The radial swing is due to the swing mechanism under the water surface, which makes the waterscape beautiful, pleasing to the eye, giving people a magical feeling, and it is a manifestation of the high-tech development of the times.

The change of the location and movement speed of the swing fountain is an important factor to produce the natural and unrestrained style of swing water. The position sensor of the fountain swing mechanism should be a waterproof 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 of fountain swing mechanism using position encoder includes: position encoder installed on swing motor shaft, high-speed counter, control computer and communication interface. As the connecting rod of the rocking mechanism generally has a large gap, in order to achieve positioning, the rocking mechanism can only reach the positioning point from one direction, so as to make its repetition accuracy. Therefore, when the swing mechanism needs to stop, it must reach the positioning point from one direction every time.

The positioning accuracy of swing mechanism is affected by motion moment and resistance moment. The motion moment depends on the power supply voltage of the motor and the motion speed before stopping, while the resistance moment is composed of the friction of the rocking mechanism, the speed of water flow and the surrounding wind force. Therefore, 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, namely, the magnitude of DC braking current and the starting braking time. A convenient way for computer control is to change the braking time.