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State-Observers for Semi-Active Suspension Control Applications with Low Sensitivity to Unknown Road Surfaces
Technical Paper
2014-01-0867
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Semi-active suspension systems aim to improve the vehicle safety and comfort. For these systems control laws are required to achieve the desired performance improvements. On the other hand, the instrumentation of the vehicle suspension typically consists only in accelerometers, which are used to measure the vertical accelerations. However, velocities and/or displacements are required to implement the most common control algorithms for semi-active suspension systems. For instance, Skyhook and Groundhook controllers require the knowledge of the suspension vertical velocities. In this article several vertical velocities estimation approaches are studied and compared. In practical applications, it is common to use simple integrators to estimate these variables; nonetheless, it is well known that integrator-based estimations present errors due to drift. In applications where high performance is required, a better estimation of the state variables of the suspension system is essential. An additional problem for the estimation process is that the system is also affected by an unknown input: the road surface. This complicates the use of traditional observer schemes, thus an Unknown Input Observer (UIO) can be considered. There are many theoretical reports dealing with state estimation in presence of unknown inputs; however, only a few of them apply these techniques to vehicle suspension systems. An observer capable of estimating the unmeasured state variables of the Quarter of Vehicle (QoV) dynamics subject to unknown road surfaces is proposed. It is shown that the decoupling of the unknown input induces observability problems, which can be overcome by reducing the observer performance. A frequency-domain analysis shows that the resulting observer presents a good level of disturbance rejection of the unknown road. In addition, it is shown that the use of frequency-analysis tools can help to elucidate how to reduce the effect of the road surface even for classical observer schemes. Early results show good performance of the proposed observer in several scenarios. A comparison between several classical estimation methods is also included.
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Citation
Hernandez-Alcantara, D., Amezquita-Brooks, L., and Morales-Menendez, R., "State-Observers for Semi-Active Suspension Control Applications with Low Sensitivity to Unknown Road Surfaces," SAE Technical Paper 2014-01-0867, 2014, https://doi.org/10.4271/2014-01-0867.Also In
References
- Karnopp D. , Crosby M. and Harwood R. Vibration control using semi-active force generators J of Eng for Industry 96 2 619 626 1974
- Valasek M. , Novak M. , Sika Z. and Vaculin O. Extended ground-hook-new concept of semi-active control of truck suspension Vehicle System Dynamics 29 289 303 1997
- Tan U. X. , Veluvolu K. , Latt W. T. , Shee C. Y. , Riviere C. and Ang W. T. Estimating Displacement of Periodic Motion With Inertial Sensors IEEE Sensor J. 8 8 1385 1388 2008
- Valcher M. E. State Observers for Discrete-time Linear Systems with Unknown Inputs IEEE Trans on Automatic Control. 44 2 397 401 1999
- Darouach M. Existence and Design of Functional Observers for Linear Systems IEEE Trans on Automatic Control. 45 5 940 943 2000
- Tsui C. C. A New Design Approach to Unknown Input Observers IEEE Trans on Automatic Control. 41 3 464 468 1996
- Yi K. and Suk B. Observer Design for Semi-Active Suspension Control Vehicle System Dynamics 23 2 129 148 1999
- Hou M. y Muller P. C. Design of Observers for Linear Systems with Unknown Inputs IEEE Trans on Automatic Control. 37 6 871 875 1992
- Hendrick K. and Rajamani R. Observer Design for Electronic Suspension Applications Vehicle System Dynamics 23 413 440 1994
- Lozoya-Santos J. , Morales-Menendez R. , Ramirez-Mendoza R. and Tudon-Martinez J. Magnetorheological Damper an Experimental Study J of Intelligent Material Systems and Structures 23 213 1232 2012
- Varrier , S. , Morales-Menendez , R. , Lozoya-Santos , J. , Hernandez , D. et al. Fault Detection in Automotive Semi-Active Suspension: Experimental Results SAE Technical Paper 2013-01-1234 2013 10.4271/2013-01-1234
- Tudon-Martinez J. , Fergani S. , Varrier S. , Sename O. , Dugard L. , Morales-Menendez R. and Ramirez-Mendoza R. Road Adaptive Semi-active Suspension in a Pick-up Truck using an LPV Controller 7th IFAC symposium on Advances in Automotive Control Tokyo 2013
- Savaresi S. and Spelta C. A Single-Sensor Control Strategy for Semi-Active Suspensions IEEE Trans on Control Systems Technology 17 1 143 152 2009
- Brogan W. L. Modern control theory 3rd Upper Saddle River, NJ Prentice-Hall 1991
- Dugard L. , Sename O. , Aubouet S. and Talon B. Full Vertical Car Observer Design Methodology for Suspension Control Applications Control Eng Practice 20 9 832 845 2012
- Aubouet S. , Dugard L. and Sename O. Experimental Results of an H ∞ -Observer for an Industrial Semi-Active Suspension 6th IFAC Symp Advances in Automotive Control Munich: Germany 2010