The specific technical improvements are as follows:
1. Adopting Direct Drive Volume Control Technology to Replace Traditional Valve Control Traditional systems rely on throttle valves for regulation, which suffer from high throttling losses and low synchronization accuracy. The new system utilizes a direct drive volume control method.
 Principle: This technology combines AC servo motors with hydraulic pumps. By changing the speed of the AC servo motor, it directly controls the output flow of the hydraulic pump, thereby precisely controlling the movement position of the hydraulic cylinder.
 Advantages: This method not only improves resolution and speed regulation range but also avoids the throttling losses of traditional valve-controlled systems, reduces oil temperature rise, and achieves energy saving and high-precision control.
2. Developing an Independent Direct Drive Pump Group Architecture To achieve independent and precise control of the six hydraulic cylinders, the system is designed with a specialized direct drive pump group.
Configuration: The pump group contains 6 custom servo motors, each driving a quantitative ultra-high pressure hydraulic pump. Each pump has a separate oil outlet connected to a specific hydraulic cylinder.
Function: This "one-to-one" drive method eliminates pressure interference and resistance differences caused by shared pipelines between cylinders, allowing movement in each direction to be regulated independently and precisely,.
3. Implementing Segmented and Tracking Control Strategies Based on Process Characteristics Specific control logic was designed for the "Empty Advance" (idle approach) and "Filling" processes, which have the highest requirements for position synchronization.
Empty Advance Process (Segmented Control): The empty advance process is divided into two segments. The first segment uses high-flow low-pressure pumps for rapid movement; the second segment switches to the direct drive pump group, using servo motors for precise fine-tuning toward the "hammer stop position" to ensure positional accuracy at the endpoint,.
Filling Process (Curve Tracking): During the filling process, the three "dead cylinders" (left, rear, bottom) are controlled targeting a specific displacement curve. Meanwhile, the three "live cylinders" (right, front, top) target the displacement of their corresponding dead cylinders, tracking them by real-time adjustment of servo motor speeds to ensure high-precision synchronization of opposing hydraulic cylinders.
4. Establishing Mathematical Models and PID Closed-Loop Control The system uses mathematical models to support control parameter tuning and incorporates sensors for closed-loop control.
 Closed-Loop Feedback: Each hydraulic cylinder is equipped with an independent high-precision displacement sensor that feeds position signals back to the control cabinet in real-time, forming a PID closed-loop servo control.
Model Optimization: Addressing the extreme weight of the hydraulic cylinder rods, researchers established flow continuity equations and force balance equations for the pump-controlled cylinders. These mathematical models serve as the basis for PID parameter tuning, ensuring the control algorithm adapts to the characteristics of the actuating mechanism.
Improvement Results: Through the improvement of these core technologies, the new hexahedral press hydraulic control system resolved the issue of low synchronization accuracy in traditional systems. Test results show that the position deviation of opposing hydraulic cylinders is controlled within 0.10 mm, effectively meeting the requirements for high-precision position synchronization in superhard material synthesis.