Main Types Of Electro-Hydraulic Servo Systems

Electro-hydraulic servo systems can be classified in various ways:
By control objective: Position control, speed control, and force (or pressure) control systems, etc.
By control method: Valve-controlled systems (flow controlled via servo valves) and pump-controlled systems (flow controlled via servo pumps).
By signal type: Analog servo systems and digital servo systems. The latter represent the current mainstream and the direction of future development due to their seamless integration with computer control.
By drive method: Direct-drive electro-hydraulic servo systems (DDV) use an AC servo motor to drive the hydraulic pump directly, eliminating the need for a servo valve; this offers advantages such as energy efficiency, a simple structure, and high contamination tolerance.