Software Enabled Variable Displacement Pumps Perry Y. Li and Tom Chase University of Minnesota
Hydraulics that plays an important role in many industry sectors. The distinct advantage of hydraulics is its ability to deliver high forces, higher power in small packages. As the industry matures, new ways to exploit these advantages must be developed to remain competitive.
In this project, a mechatronics approach is proposed to redesign variable displacement pumps. Current variable displacement pumps are relatively large and their dynamic responses are low. Compact and high performance variable displacement pumps can significantly improve energy efficiency and address new applications. By combining a compact fixed displacement pump with a high speed pulse width modulated (PWM) on/off valve, a highly controllable, compact variable displacement pump capable of achieving many new software enabled feature will be possible. These features can be used to improve many aspects of system efficiency and performance.
In this research, two key obstacles will be addressed. 1) A high speed on/off PWM valve will be developed; 2) A modeling and control design framework for PWM controlled systems will be developed. In addition, various software enabled features will be demonstrated experimentally.
This project will improve the power and force density of hydraulic pumps, and the energy efficiency of the use of hydraulics in general. By making available hydraulic power supplies that are compact, it will be possible to capture new markets and to inspire new applications, such as hydraulic personal robots, rescue tools, hydraulic power trains, etc. The proposed idea can be readily extended to the design of variable displacement motors, and variable hydraulic transformers. The high flow high speed PWM on/off valve that will be developed in this research will also be useful for many other hydraulic control applications. A rigorous theoretical framework will also be developed for the modeling and design of finite frequency PWM controlled systems. Advances in this area will impact many areas of motion control since PWM is widely used, but yet, rigorous understanding is still lacking.
The results of this research will impact the curricula of various controls and fluid power courses. The graduate students will participate in interdisciplinary research, with close interaction with industry through regular consultation and summer internship. Undergraduate students will be involved in this research through participation in experiments and design projects. Through regular meetings, this project will foster strong relationships between the local fluid power industry and the university. In addition, exchanges with a local power electronics research group will also be established.
