In the field of modern industrial automation and precision control, servo valve, as a high-precision and high-response hydraulic control element, is widely used in aerospace, robots, CNC machine tools, metallurgical equipment and other high-end equipment. Multi-channel servo valve plays an important role in complex systems because it has multiple independent or cooperative control channels and can realize synchronous or differential control of multiple actuators. This paper will discuss the distribution principle, distribution strategy and application of multi-channel servo valve.
First, the basic structure and working principle of multi-channel servo valve
Multi-channel servo valve usually consists of several independent servo valve cores, and each channel can independently receive control signals and adjust the corresponding hydraulic flow and pressure. Its core working principle is to drive the torque motor or proportional electromagnet through the input of electrical signals, and then control the position of the valve core, change the flow direction and flow rate of hydraulic oil, so as to accurately control the motion state of the actuator.
Compared with single-channel servo valve, the biggest advantage of multi-channel servo valve is that it can control multiple hydraulic cylinders or motors at the same time, realize multi-axis linkage and coordinated control, and improve the dynamic response and control accuracy of the system.
Second, the distribution mode of multi-channel servo valve
The distribution of multi-channel servo valves in the system mainly involves the following aspects:
1. Distribution according to the number of executing agencies
Each channel can independently control an actuator (such as a hydraulic cylinder or hydraulic motor). For example, in a six-degree-of-freedom platform system, six independent servo valve channels are usually needed to control the actions of six hydraulic cylinders respectively, so as to realize complex motion in space.
2. Distribution by function
In some systems, different channels can undertake different tasks. For example, one part of the channel is used for speed control and the other part is used for position or force control. This distribution method is common in automation equipment that needs multi-mode control.
3. Parallel and series distribution
Multi-channels can be used in parallel to improve flow output, or in series to enhance control accuracy and response speed. This combination method is especially common in occasions with high load and high precision requirements.
4. Redundancy allocation and fault-tolerant control
Multi-channel servo valve can also be used for redundant design in systems with high safety requirements, such as aircraft flight control system. When a channel fails, the system can automatically switch to the standby channel to ensure the stable operation of the system.
Third, the control strategy of multi-channel servo valve distribution
In order to achieve efficient and accurate control effect, multi-channel servo valves often adopt the following control strategies:
-PID control: each channel adopts an independent PID controller, which is suitable for situations where the actuators are independent of each other.
-Cross-coupling control: through the information interaction between channels, higher precision synchronous control is realized, which is often used in multi-axis linkage control systems.
-Fuzzy control/adaptive control: In the nonlinear and uncertain environment, intelligent control strategy is adopted to improve the robustness and adaptability of the system.
Fourth, application examples
Taking the hydraulic drive system in industrial robots as an example, multi-channel servo valves can control the expansion, rotation and grasping actions of each joint respectively. By reasonably distributing the control tasks of each channel and combining with advanced control algorithm, not only high-speed and high-precision operation can be realized, but also energy consumption can be effectively reduced and equipment life can be prolonged.
V. Conclusion
With the development of intelligent manufacturing and high-end equipment, the application of multi-channel servo valve will be more and more extensive. Reasonable channel allocation strategy can not only improve the overall performance of the system, but also enhance the stability and reliability of the system. In the future, with the continuous progress of digital control technology and artificial intelligence algorithm, multi-channel servo valve will play a greater role in more complex and changeable control systems.