基于预测控制的活塞式压力计活塞位置平衡技术

The piston position balancing technology of piston pressure based on predictive control

高压(大于250 MPa)全自动活塞式压力计需要控制系统能快速找到达到活塞稳定浮起的位置平衡点。为了减少仪器体积,一般采用尽可能小的活塞直径,微小的压力变动就会导致活塞位置的起伏。为了快速实现活塞位置的快速平衡,提出了使用广义预测控制(GPC)活塞位置平衡的控制方法。在提出的预测控制算法中,综合考虑了活塞压力计在加压过程中存在的多个变量对活塞下降速度的影响,通过对输入输出的模型辨识,构造出压力计活塞位置控制的数学模型,并通过广义预测算法预测活塞的运动行为。结果表明,广义预测控制对于活塞位置的快速平衡具有良好效果。

The high pressure(higher than 250 MPa)automatic piston pressure gauge needs the control system to quickly find the position balance point where the piston can float stably.In order to reduce the volume of the instrument,the diameter of the piston is generally as small as possible,and the slight pressure change will cause the piston position ups and downs.In order to quickly realize the fast balance of piston position,a control method of piston position balance using generalized predictive control(GPC)is proposed.In the proposed predictive control algorithm,the influence of multiple variables existing in the piston pressure gauge on the piston descending speed in the process of pressurization was comprehensively considered,and the mathematical model of the pressure gauge piston position control was constructed through the model identification of the input and output.The motion behavior of the piston was predicted by a generalized prediction algorithm.The results showed that generalized predictive control had a good effect on the rapid balance of piston position.