Bond Graph Modelling for Non-Linear Hydro-Mechanical Systems

Abstract

Bond graphs are a concise pictorial representation of the interactive dynamics of all types of engineering systems. Relatively few symbols are needed to represent these systems, and this includes non-linear mechanics interacting with hydraulic or pneumatic subsystems. Agricultural and construction equipments and vehicles are examples of such complex systems. Assembling overall system models of such complex systems can be very difficult without a unifying procedure that indicates computational causality as the model is developed. Bond graphs allow for the continuous assessment of causality as a model is developed, regardless of the non-linearity of the individual pieces. This causality indicates computational problems and allows the modeller to address these problems prior to deriving equations or attempting to simulate the system. The development of such models is done here as generally as possible, but is applied to an unstable backhoe as an example. The systematic modelling procedures of a backhoe are used for the development of individual subsystems which are then combined into an overall computational model.

A review on modeling, identification and servo control of robotic excavator

“…For system analysis and controller design purposes, one always gave out the actuator dynamics, soil-tool dynamics, kinematics, and dynamics of the manipulator respectively. However, the bond graph method can describe the interactive dynamics of all types of engineering system by a few symbols in a uniform procedure (Margolis et al, 2005). Muvengei et al (2009) modeled the mechanical dynamics of an excavator by bond graphs, they indicated that bond graph method was more computationally efficient than Newton-Euler method.…”

Bond graph modelling of a hydraulic cylinder-actuated planar manipulator

“…9. The elements k p and r p are assigned very high values, so that they yield a highfrequency oscillation at the beginning and decay rapidly [5,11,20]. Use of this model to resolve the problem of differential causality at different joints is shown in Fig.…”

“…Moreover, it is also preferred to compete with the requirement of more power-to-weight ratio [1,2]. In many applications, particularly for linear actuation, hydraulic systems appear as the only possibility of attaining the force required [3][4][5]. Usually, hydraulic systems consist of hydraulic circuit and mechanism which interact dynamically with the hydraulic components.…”

Operational Fault Diagnosis in Industrial Hydraulic Systems Through Modeling the Internal Leakage of Its Components

“…The basics of bond graph based control and substructuring are analyzed by Gawthorp et al (2009), while Krishnaswamy and Li (2006) used the Bond Graph method in the passive teleoperation of a hydraulic backhoe. Additional work in the field of bond graph modeling of nonlinear hydro-mechanical systems has been conducted by Margolis and Shim (2005), while Li and Ngwempo (2005) have used bond graph modeling in electro-hydraulic valves. The dynamic response of a high pressure hydraulic system using bond graphs is examined by Barnard and Dransfield (1977), while Dransfield (1981) dealt with the application of bond graphs to hydraulic systems.…”