Development of a Low Cost Ventilator using a Proportional Solenoid Valve

This paper describes the development of portable mechanical ventilator using a proportional solenoid valve whose aim is to regulate the flow rate of oxygen to the patient together with an Arduino Mega2560 as the main controller for the machine before delivering the required volume to the patient; base on their ideal body weight so as to prevent blowing out the lungs The aimed of this development is to save and improve the quality of lives of patients with respiratory problems rather than replacing the existing ventilator. Furthermore, test analysis was conducted to evaluate its performance and also the comparative analysis between the standard and the developed ventilator showed the reasons why most hospitals don’t have ventilators.

Nonlinear cascade control of high-response proportional solenoid valve based on an extended disturbance observer

With the gradually increasing usage of high-response proportional solenoid valve in the middle- and high-end electronic hydraulic system, to possess a superior performance controller is always most important for high-response proportional solenoid valve. Thus, many novel nonlinear control algorithms, such as sliding mode control and adaptive robust control, are researched and applied to high-response proportional solenoid valve. However, the strict condition of full-state feedback usually cannot be met, since there are no velocity and acceleration measurements available in high-response proportional solenoid valve. Therefore, we proposed an extended disturbance observer to observe the velocity of the high-response proportional solenoid valve’s spool assembly at first. Or rather, the extended disturbance observer is designed to observe the disturbances in the model of high-response proportional solenoid valve and the velocity is also obtained as a by-product. And then, a nonlinear cascade controller based on the extended disturbance observer is designed. The proposed extended disturbance observer is driven by both the estimation error and the virtual input discrepancy of nonlinear cascade controller. The nonlinear cascade controller is designed by utilizing backstepping technique. The stability of the overall closed-loop system is proved according to the Lyapunov theory. As a comparison, a desired compensation nonlinear cascade controller is also applied to the same high-response proportional solenoid valve. The experiment results demonstrate that the proposed nonlinear cascade controller based on extended disturbance observer has an excellent performance under multiple working conditions. Even when the supply pressure has severe fluctuations, the nonlinear cascade controller based on extended disturbance observer can still maintain high performance.

Shift Quality Analysis of Heavy-Duty Vehicle Automatic Transmission Shift Control Valve

The structural concepts of Switch solenoid valve and proportional solenoid valve were proposed for the hydraulic shift control system of some hydrodynamic mechanical automatic transmissions. Shift oil pressure of stationary combination valve and proportional solenoid valve was modeled, simulated, contrasted and analyzed by dynamic simulation software in order to study the shift quality of heavy-duty vehicle automatic transmission. The results show that proportional solenoid valve is better to control the characteristic of shift oil pressure, reduce shift shock, improve shift quality and comfort than stationary combination valve. The correctness and validity of the model were verified through bench test, which reflected the dynamic characteristics of shift oil pressure of hydrodynamic mechanical automatic transmission. The results can be used to match the performance and predict heavy-duty vehicle shifting process, and to further lay the foundation for the enhancement of shift performance of the system.