Adaptive Control of Generalised Dynamically Substructured Systems

IET Control Theory Appl.

2010

Dynamically substructured systems (DSS) are increasingly used by the dynamics testing community. DSS involves the physical testing of full size critical components in parallel with numerical testing of the remaining components. This has certain advantages over other testing methods [24]. However, the synchronization of the signals at the interface between the physical and numerical substructures of DSS requires a high fidelity controller. In practice, the performance of the DSS testing can be significantly degraded by input saturation of the actuators. In this paper, we use model predictive control (MPC) to cope with the saturation problem in DSS. To facilitate the MPC and observer design for DSS, a modified DSS framework based on an existing one is proposed [22]. As a case study, a quasi-motorcycle (QM) system is converted into the modified DSS framework and a traditional on-line MPC control strategy is implemented in real-time.

Section: Successful Existing Control Strategies For Dss Include Lineamentioning

confidence: 99%

Section: Successful Existing Control Strategies For Dss Include Lineamentioning

confidence: 99%

Section: Successful Existing Control Strategies For Dss Include Lineamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Model predictive control of dynamically substructured systems with application to a servohydraulically actuated mechanical plant

IET Control Theory Appl.

2010

A comparative study and unification of two methods for controlling dynamically substructured systems

Earthq Engng Struct Dyn

2016

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. SUMMARY This paper addresses the problem of advanced testing of systems via the principle of dynamic substructuring. Use is made of the hybrid simulation (HS) scheme framework to develop a new method of synthesis for the dynamically substructured system (DSS) scheme of Stoten and Hyde; [1]. Principal reasons for doing this are (i) to improve upon the original method of DSS synthesis by adopting the more intuitive framework of HS and (ii) to enable the amalgamation of HS and DSS into a unified substructured system (USS) scheme, so that the significant advantages of DSS can be incorporated into an existing HS scheme as a straightforward retrofit. Having established the common framework for HS/DSS the paper also illustrates, by way of an example, compensator/controller synthesis for the two schemes, together with their advantages and disadvantages. In doing this both schemes are retained in their basic forms, i.e. there are no additional control embellishments used in this work, such as delay compensation, adaptive control or other advanced control methods. In order to maintain as much transparency as possible, use is made of well-known classical control techniques. Common problems associated with the substructure testing technique are also investigated, including the effects of physical parameter uncertainty, pure delays in signals and a 'split-mass' in the substructure formulation. It is shown that, although the new formulation of controlled-DSS requires more design effort than compensated-HS, the advantages of DSS in terms of stability and robustness significantly outweigh this small disadvantage at the design stage.

Testing of dynamically substructured, base‐isolated systems using adaptive control techniques

Lin

Earthq Engng Struct Dyn

et al. 2009

SUMMARYExperimental techniques for testing dynamically substructured systems are currently receiving attention in a wide range of structural, aerospace and automotive engineering environments. Dynamic substructuring enables full-size, critical components to be physically tested within a laboratory (as physical substructures), while the remaining parts are simulated in real-time (as numerical substructures). High quality control is required to achieve synchronization of variables at the substructuring interfaces and to compensate for additional actuator system(s) dynamics, nonlinearities, uncertainties and time-varying parameters within the physical substructures. This paper presents the substructuring approach and associated controller designs for performance testing of an aseismic, base-isolation system, which is comprised of roller-pendulum isolators and controllable, nonlinear magnetorheological dampers. Roller-pendulum isolators are typically mounted between the protected structure and its foundation and have a fundamental period of oscillation far-removed from the predominant periods of any earthquake. Such semi-active damper systems can ensure safety and performance requirements, whereas the implementation of purely active systems can be problematic in this respect. A linear inverse dynamics compensation and an adaptive controller are tailored for the resulting nonlinear synchronization problem. Implementation results favourably compare the effectiveness of the adaptive substructuring method against a conventional shaking-table technique. A 1.32% error resulted compared with the shaking-table response. Ultimately, the accuracy of the substructuring method compared with the response of the shaking-table is dependent upon the fidelity of the numerical substructure.