A software application for visualizing and understanding hydraulic and pneumatic networks

Abstract

Hydraulic and pneumatic networks are highly nonlinear and difficult to analyze. This study presents a software application designed to help students, visualize and understand fluid systems' dynamic behaviors. The application uses a combined bond graph and singular perturbation approach for system equation formulation. A standard iterative and adaptive integrator provides online numerical solutions to the system equations. Coupled to the integrator's output are a graphical animation subsystem and an instrumentation subsystem. The animation subsystem is responsible for rendering movable components on screen, at every simulation time-step, creating the illusion of continuous movement. The instrumentation subsystem collects and displays numerical data in numerical and graphical forms. An interesting contribution of this fluid system analyzer is its ''user-in-the-loop'' feature. This feature allows students to become active participants by enabling them to interact with network components while a simulation run is in progress.

Constructing virtual hydraulic circuits using Flash

“…However, courseware development using such general technologies requires much stronger programming ability which beyond most teachers. Although the courseware presented in [14] seems more relational to our project's objectives, its description is not detailed enough to provide a clear picture about how to develop a virtual hydraulic circuit to most teachers who are lack of programming technology.…”

“…Wong et al [14] present a software application for inspecting hydraulic circuits' dynamic behaviors. The application consists of several function blocks including system equation formulation, numerical simulation on the system equations, dynamic data visualization, as well as animations representing components' behaviors.…”

“…Among works mentioned above, most highly interactive coursewares adopting numerical simulation technologies are developed using general programming languages, such as Visual Basic [8,14,37], C or VC [9,35], Java [38,40]. However, courseware development using such general technologies requires much stronger programming ability which beyond most teachers.…”

“…And the created coursewares are developed with a variety of development softwares and programming technologies, from general program languages, such as C family [9,13,19,35,36], Visual Basic [8,14,37], Java family [38À40], Fortran [36], Matlab [9,41,42], to more professional softwares, such as Macromedia Authorware [26], Microsoft PowerPoint, Macromedia Flash [12,38], VRML [43], OpenGL [19], etc. There are also coursewares involving special softwares, such as Microsoft Excel [36].…”

“…With the development of computer technology and multimedia technology, courseware is becoming more and more widely adopted in almost all education levels (primary education [2], middle school education, and college education) [3,4] and most disciplines (mathematics [5À7], electrostatic [8], electromagnetics [9À11], thermotics [12,13], hydraulics [14,15], pneumatics [16], mechanics [17,18], FEM analysis [19,20] physics [21], chemistry [22,23], music [23], language [23], programming [24,25], etc). Recent researches also show that courseware can be a valuable complement to education [26À31].…”