Difference between Servo and Digital hydraulic

Servo valve + sensor closed loop control system theory is complete, but there are many uncertainties in the application, so there are a lot of technical know-how above servo valve control system. For example: on the servo valve frequency selection, the actuator (hydraulic cylinder and hydraulic motor) minimum starting pressure selection, the actuator load stability and stable pressure design, high and low temperature lead to changes in liquidity to the hydraulic oil and so on, therefore, servo valve control system only a few companies and a few experts can master the implementation. In addition, the servo valve control system with high requirements for the use and maintenance of the technology, so that the servo valve control system is not stable and reliable, comprehensive cost is very high, often 10 times to reach the total price of the device.

Digital hydraulic technology is the upgrading technology from servo valve control technology, and it is the latest trend in the international popular technology. The Chinese in this field leading position in the world. A lot of digital hydraulic products have been widely used in the fields of national defense, hydroelectric power, metallurgy, heavy machinery, it replaces the servo valve control system to achieve higher technical level, reduce the comprehensive cost, significantly better than servo valve control system.

As the digital hydraulic structure design clever, so that the cylinder, valve, feedback and control can be combined into a whole, to achieve a fully digital performance. It makes the original complex servo hydraulic control system into a simple component, simplifying the design, commissioning, use and maintenance. Digital hydraulic technology is achieved through a clever way of internal feedback, to achieve the hydraulic follow the characteristics of low-power motor, the output of the force to get thousands of times to enlarge.

Digital hydraulic is a built-in closed loop, using open elements (alos can be closed loop control) of the independent components. Users simply connect the digital cylinder to the hydraulic pump, the electric pulse into the digital cylinder (motor), without the need for complex parameters of the set and adjust, you can achieve micron-level control accuracy. "The digital hydraulic pressure is to return the power back to the computer (the computer turns the loop to send the pulse command), while the digital power amplification is left to the hydraulic (digital hydraulic voltage to pulse into precision power drive control)".

Digital hydraulic is a typical Internet plus technology, its origin and development, to create the conditions for China to enhance the level of automation, which will promote China's equipment manufacturing industry to play a significant role to upgrade. The Digital hydraulic technology is the most powerful guarantee for the equipment manufacturing industry to achieve the goal of "Industry 4.0" and "made in China 2025".

  • Digital hydraulic and servo hydraulic maximum difference is that the digital hydraulic using a mechanical feedback control, equipment performance is more stable

  • The complex system into a single element

  • Follow motor characteristics, to achieve power amplification

  • Fully digital transmission characteristics

  • No control parameters tuning

  • System design, sets, commissioning, maintenance is simple

  • Significantly reduce overall operating costs

  • fieldbus, network, analog interfaces easy

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