Explore various control systems for musical fountains

11 Jul 2020

The musical fountain is based on the program-controlled fountain, and a music fountain control system is added (this control system will be described in detail below, but it will not be described here). The computer decodes and encodes the audio and MIDI signals, and then outputs the signal to the control system to synchronize the shape and lighting changes of the fountain with the music, so as to achieve a complete combination of the water type, light color and musical emotion of the fountain. The performance is more vivid and rich in content, reflecting the art of water.

The ordinary music fountain system is mainly composed of an audio control system, a waterway control system, a lighting control system, and an electrical control system. The audio control system includes players, amplifiers, power amplifiers, speakers, sound columns, etc.; the waterway control system is mainly composed of fountain controllers, frequency converters, water pumps, multi-function regulating valves, sprinklers and water supply pipe networks; lighting control systems include various Lamps, lamp control software systems, lighting control loop systems, etc.; electrical control systems include weak current control loops, strong current systems, water pumps, nozzles and other hardware.

The control loop includes a trigger switch, an integrated control chip, a music output loop, a water pump drive loop, and a light display loop. The start of the trigger is connected to the trigger input terminal of the integrated control chip, and the music output circuit, the pump driving circuit and the light display circuit are respectively connected to the corresponding output terminals of the integrated control chip. Trigger the switch to trigger the work of the integrated control chip, so that the integrated control chip outputs audio signals to the music output circuit to play music, and at the same time, respectively output a stable pulse and a pulse that changes synchronously according to the music melody and rhythm to the motor amplifier circuit, and the superimposed Change the current, and use this current to control the pump motor to drive the pump to change the pumping height as the music changes. The rhythm and intensity of the music are converted into a control signal. This signal controls a voltage control device. After the power supply passes through the voltage control device, the output voltage also changes with the change of the music, which in turn controls the pump motor. Changing the frequency changes the speed of the motor and the pressure of the pump. The different frequencies of the music are processed by the integrated control chip and sent to the control end of the variable frequency motor, so that the speed of the motor changes with the tone, rhythm and strength of the music, the pressure of the water pump changes, and the height of the water column sprayed changes. At the same time, multiple sets of nozzles are controlled by several sets of equipment.

The music fountain control system is a complex on-site control system integrating sound, light and electricity. With the continuous promotion of frequency conversion speed regulation technology, special frequency converters for water pumps have been widely used in water pump control. A large number of water pumps are needed in the music fountain system to control the circulating water of the fountain. According to the working characteristics of the water pump, the pump flow rate is proportional to the pump speed Relationship, the flow of the pump can be directly controlled by adjusting the pump speed. The music fountain system needs to realize real-time adjustment of the water volume of the fountain. Therefore, the frequency conversion speed regulation technology is more suitable for use in the music fountain system. In addition, according to the characteristics of the water pump, the use of frequency conversion speed regulation technology has a certain energy saving effect, which is why the frequency converter is popularized and applied in the music fountain control system. With the continuous promotion of the application of musical fountains, various fountain-specific controllers have also been continuously improved. The fountain controller or running spring controller has multi-function switch output, standard analog output and built-in communication interface circuit, which can communicate with the host computer through RS-485 or bus mode, and the output standard current or voltage signal can be used as frequency conversion The given signal of the governor speed control, combined with the unique functions of the special frequency converter for the music fountain, can achieve complex control.

The principle of the control system is to sample and process the A/D converted audio signal through the assembly program in the integrated control chip, control the single-phase motor in stages, and finally achieve the method of controlling the flow rate of the nozzle. Program control or manual button control solenoid valve to control the pattern. The audio signal is also used to control the change of the color of the light and the brightness of the light, so that the light effect and the water form of the fountain change with the rhythm of the music. The music fountain is a comprehensive waterscape composed of computer-controlled sound, light and nozzle holes to produce different shapes, different colors and match the rhythm of music. The shape of the water will change as the sound rises and falls, and the illumination of the light can form a beautiful and colorful fountain. Most audio control systems use a multimedia PC to play music through a host computer program.

In terms of the control of the fountain system, the fountain pump has currently adopted variable frequency speed regulation technology to realize the stepless speed regulation of the pump. It can adjust the speed of the pump at any time according to the strength of the audio signal. The multi-function valve and universal nozzle are controlled by the dedicated controller of the fountain. Various patterns and shapes can be realized according to the setting procedure. The music fountain control system is a control system that integrates audio control technology and program control technology. It belongs to an industrial field control system. Most of its host computers are composed of multimedia industrial PCs. It can achieve full-time real-time sound control. According to the melody, The strength of the rhythm and audio frequency controls the fountain system. Its electrical control system mainly has the following three forms:

Centralized control: The centralized control system adopts a radial structure, which can meet the music fountain with the control room closer to the pool, smaller scale, and less pattern changes.

Fieldbus control: The fieldbus is a serial data communication link that realizes the connection between the fountain's field basic control equipment and the superior control equipment. The advantages of fieldbus are: one transmission line can control multiple devices, the control system is simple, installation and maintenance are easy; the use of digital communication technology has strong anti-interference and high precision; the control functions are distributed to the fountain site, which improves the electrical control system. Reliability and flexibility.

Network field bus control: The structure of the network field bus is similar to the field bus, and its performance is better than the latter. The network field bus belongs to a distributed control system, the electronic control system runs faster, meets the requirements of real-time control of the music fountain, and has more stability Good; there are many types of network connection structures, which can support both bus and radial types, and a mixed structure can be used; the main difference between the network field bus and the field bus is that the former uses a dedicated network operating system to realize the interoperation between various devices on the network.

In short, with the change of music, the musical fountain adds a beautiful visual and auditory feast to the people of the city at night. It is a romantic and leisure entertainment project at night in fast-paced city life.

Keywords: musical fountain

Originally published 11 Jul 2020, updated 11 Jul 2020.