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Abstract: For the proportional directional valve controlled by two proportional solenoids, the normal control method (NCM) energizes only one solenoid at a time. The performance of the valve is greatly influenced by the nonlinearity of the proportional solenoid, such as dead zone and low force gain with a small current, and this effect cannot be eliminated by a simple dead-zone current compensation. To avoid this disadvantage, we propose the differential control method (DCM). By employing DCM, the controller outputs differential signals to simultaneously energize both solenoids of the proportional valve, and the operating point is found by analyzing the force output of the two solenoids to make a minimum variation of the current force gain. The comparisons of the valve response characteristics are made between NCM and DCM by nonlinear dynamic simulation and experiments. Simulation and experimental results show that by using DCM, the frequency response of the valve is greatly enhanced, especially when the input is small, which means that the dynamic characteristics of the proportional valve are improved.

比例方向阀差动控制算法

研究目的：对于由两个比例电磁铁控制的比例方向阀，常用的控制方法仅给其中一个电磁铁供电，因此，阀的性能受到比例电磁铁特性影响，如死区、小电流时的力增益非线性等，且此影响无法用简单的死区电流补偿消除。本文提出差动控制方法（differential control method），以改善比例电磁铁的性能。
创新要点：在建立比例阀电磁铁非线性模型的基础上，提出了差动控制策略，建立差动控制器输出互成差动关系的两路控制信号，分别激励比例阀的左右两个比例电磁铁，以总体力增益恒定为优化目标选取最佳工作点，从而减小比例阀电磁铁的非线性，改善比例方向阀性能。
方法提亮：同时驱动比例方向阀的两个比例电磁铁，使两路控制信号满足差动关系，合理配置静态工作点使两路比例电磁铁的合力线性度最高，并通过阀芯位移反馈实现对阀芯位置的闭环控制。
重要结论：实验结果表明，差动控制算法能够有效改善比例阀电磁铁的非线性特性，提高比例方向阀阀心位移的控制精度与响应速度。
差动控制方式；频率响应；比例方向阀；阀芯位移反馈

[1]Amirante, R., Del Vescovo, G., Lippolis, A., 2006. Flow forces analysis of an open center hydraulic directional control valve sliding spool. Energ. Conv. Manag., 47(1): 114-131.

[2]Amirante, R., Innone, A., Catalano, L.A., 2008. Boosted PWM open loop control of hydraulic proportional valves. Energ. Conv. Manag., 49(8):2225-2236.

[3]Amirante, R., Catalano, L.A., Poloni, C., et al., 2014. Fluid-dynamic design optimization of hydraulic proportional directional valves. Eng. Optim., 46(10):1295-1314.

[4]Bu, F., Yao, B., 2000. Performance improvement of proportional directional control valves: methods and experiments. Proc. ASME Dynamic Systems and Control Division, p.297-304.

[5]Del Vescovo, G., Lippolis, A., 2003. Three-dimensional analysis of flow forces on directional control valves. Int. J. Fluid Power, 4(2):15-24.

[6]Devarajan, D., Stanton, S., Knorr, B., 2003. Multi-domain modeling and simulation of a linear actuation system. Proc. Int. Workshop on Behavioral Modeling and Simulation, p.76-81.

[7]Elmer, K.F., Gentle, C.R., 2001. A parsimonious model for the proportional control valve. Proc. Inst. Mech. Eng. C J. Mech. Eng. Sci., 215(11):1357-1363.

[8]Gamble, J.B., Vaughan, N.D., 1996. Comparison of sliding mode control with state feedback and PID control applied to a proportional solenoid valve. J. Dynam. Syst. Meas. Contr., 118(3):434-438.

[9]Jin, B., Zhu, Y.G., Li, W., 2013. PID parameters tuning of proportional directional valve based on multiple orthogonal experiments method: method and experi-ments. Appl. Mech. Mater., 325:1166-1169.

[10]Kajima, T., 1993. Development of a high-speed solenoid valve-investigation of the energizing circuits. IEEE. Trans. Ind. Electron., 40(4):428-435.

[11]Khoshzaban Zavarehi, M., Lawrence, P.D., Sassani, F., 1999. Nonlinear modeling and validation of solenoid-controlled pilot-operated servovalves. IEEE/ASME Trans. Mecha-tron., 4(3):324-334.

[12]Kong, X., Wang, H., 2010. A spool displacement control system of proportional valve based on digital observer. Key Eng. Mater., 455:110-115.

[13]Li, K., Mannan, M.A., Xu, M., et al., 2001. Electro-hydraulic proportional control of twin-cylinder hydraulic elevators. Contr. Eng. Pract., 9(4):367-373.

[14]Liu, Y., Dai, Z., Xu, X., et al., 2011. Multi-domain modeling and simulation of proportional solenoid valve. J. Cent. South Univ. Technol., 18(5):1589-1594.

[15]Ruderman, M., Gadyuchko, A., 2013. Phenomenological modeling and measurement of proportional solenoid with stroke-dependent magnetic hysteresis characteristics. IEEE Int. Conf. on Mechatronics, p.180-185.

[16]Sampson, E., Habibi, S., Burton, R., et al., 2004. Effect of controller in reducing steady-state error due to flow and force disturbances in the electrohydraulic actuator system. Int. J. Fluid Power, 5(2):57-66.

[17]Vaughan, N.D., Gamble, J.B., 1996. The modeling and simulation of a proportional solenoid valve. J. Dynam. Syst. Meas. Contr., 118(1):120-125.

[18]Yuan, Q., Li, P.Y., 2002. An experimental study on the use of unstable electrohydraulic valves for control. American Control Conf., p.4843-4848.