其次，对反重力铸造控制方案进行了研究。
Secondly, the control project of counter-gravity casting is researched.
镁合金密度小、粘度低、流动性好，很适合于反重力铸造。
Magnesium alloy with lower density, lower viscosity and excellent liquidity is suitable for anti-gravity casting.
由于反重力铸造过程的时滞性、不确定性、复杂性，难以建立精确的数学模型。
It is hard to build a precise math model for counter-gravity casting process for its time lag, uncertainty and complexity.
相比传统的反重力铸造技术，该技术配合合适的浇注系统对铸件性能有明显的改善作用。
Compared with traditional counter gravity casting technique, the technique combining with appropriate gating system makes great contributions to the enhancement of mechanical property of castings.
对于大型反重力铸造设备的气路系统，重点从气路系统的进气环节、调节环节和排气环节进行了设计研究。
Thirdly, the paper provides lots of information on the pneumatic system of the equipment, puts emphasis on the design of gas-in part, adjustment part and gas-out part of different systems.
在分析反重力铸造过程控制对象数学模型的基础上，设计了PID控制器，并采用临界稳定法结合MATLAB仿真确定了PID参数。
After the mathematics model of the control object of the counter-gravity casting process is analyzed, PID controller is designed, and the PID parameters are determined by MATLAB simulation.
试验研究了反重力浇注条件下，铝合金消失模真空低压铸造的充型流动特性。
Mold filling characteristics of Al alloy in vacuum lost foam low pressure casting (VLFLPC) under counter gravity condition were examined.
试验研究了反重力浇注条件下，铝合金消失模真空低压铸造的充型流动特性。
Mold filling characteristics of Al alloy in vacuum lost foam low pressure casting (VLFLPC) under counter gravity condition were examined.
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