GT Car's CG height control on a rough road by using series active variable geometry suspension

Document Type : Invited by Davoud Younesian


School of Automotive Engineering, Iran University of Science and Technology, Tehran, Iran


This paper addresses the vehicle's CG (center of gravity) height control enhancement for the new road vehicle Series Active Variable Geometry Suspension (SAVGS) concept using the PID control technique. Thus, the study utilizes a nonlinear full-car model that accurately represents the dynamics and geometry of a high-performance car with the new double-wishbone active suspension concept. The proposed controller is installed on the nonlinear full-car model, and its performance is examined by the parameters CG Height and Pitch. In this study, PID is tuned by a Genetic Algorithm, and thus, a robust control system is designed. Finally, the system's robustness is examined through four different simulation configurations, such as different speeds and different road conditions. The vehicle is supposed to be moving to 20 km/h and 100 km/h horizontal speed, and also it is going through Road Classes types C and D. Figures show that this suspension system successfully controls vehicle CG height around a desirable height (0.5m) and does not make harmful impacts on vehicle pitch angle.


  • The use of a simple optimized PID controller on a vehicle with SAVGS is proposed.
  • Studying SAVGS on rough surfaces is the second contribution of this paper.
  • Using GA for PID tuning is found having good performance for controller optimization.
  • Having vehicle’s Height Control as the main objective of the SAVGS tuning is proposed.


Main Subjects

[1] A. Hać, Optimal linear preview control of active vehicle suspension, Vehicle system dynamics, 21 (1992) 167-195.
[2] L.R. Miller, Tuning passive, semi-active, and fully active suspension systems, in:  Proceedings of the 27th IEEE Conference on Decision and Control, IEEE, 1988, pp. 2047-2053.
[3] R. Sharp, D. Crolla, Road vehicle suspension system design-a review, Vehicle system dynamics, 16 (1987) 167-192.
[4] D. Sammier, O. Sename, L. Dugard, Skyhook and H8 control of semi-active suspensions: some practical aspects, Vehicle System Dynamics, 39 (2003) 279-308.
[5] D. Fischer, R. Isermann, Mechatronic semi-active and active vehicle suspensions, Control engineering practice, 12 (2004) 1353-1367.
[6] C. Arana, S.A. Evangelou, D. Dini, Pitch angle reduction for cars under acceleration and braking by active variable geometry suspension, in:  2012 IEEE 51st IEEE Conference on Decision and Control (CDC), IEEE, 2012, pp. 4390-4395.
[7] C. Arana, S.A. Evangelou, D. Dini, Series active variable geometry suspension for road vehicles, IEEE/ASME Transactions On Mechatronics, 20 (2014) 361-372.
[8] C. Arana, S.A. Evangelou, D. Dini, Car attitude control by series mechatronic suspension, IFAC Proceedings Volumes, 47 (2014) 10688-10693.
[9] C. Arana, S.A. Evangelou, D. Dini, Series active variable geometry suspension application to chassis attitude control, IEEE/ASME Transactions on Mechatronics, 21 (2015) 518-530.
[10] S. Evangelou, C. Kneip, D. Dini, O. De Meerschman, C. Palas, A. Tocatlian, Variable-geometry suspension apparatus and vehicle comprising such apparatus, in, Google Patents, 2015.
[11] C. Cheng, S.A. Evangelou, C. Arana, D. Dini, Active variable geometry suspension robust control for improved vehicle ride comfort and road holding, in:  2015 American Control Conference (ACC), IEEE, 2015, pp. 3440-3446.
[12] C. Arana, S.A. Evangelou, D. Dini, Series active variable geometry suspension application to comfort enhancement, Control Engineering Practice, 59 (2017) 111-126.
[13] J.-Z. Feng, J. Li, F. Yu, GA-based PID and fuzzy logic control for active vehicle suspension system, International Journal of Automotive Technology, 4 (2003) 181-191.
[14] A.A. Basari, Y.M. Sam, N. Hamzah, Nonlinear active suspension system with backstepping control strategy, in:  2007 2nd IEEE Conference on Industrial Electronics and Applications, IEEE, 2007, pp. 554-558.
[15] M. Mollajafari, H.S. Shahhoseini, An efficient ACO-based algorithm for scheduling tasks onto dynamically reconfigurable hardware using TSP-likened construction graph, Applied Intelligence, 45 (2016) 695-712.
[16] Anon, Autosim 2.5+ Reference Manual, in, Mechanical Simulation Corp., 1998.
[17] J. Lin, R.-J. Lian, Intelligent control of active suspension systems, IEEE Transactions on industrial electronics, 58 (2010) 618-628.
[18] M. Thommyppillai, S. Evangelou, R.S. Sharp, Advances in the development of a virtual car driver, Multibody System Dynamics, 22 (2009) 245-267.
[19] T.C. ISO/TC, M. Vibration, S.S.S. Measurement, E.o.M. Vibration, S.a.A.t. Machines, Mechanical Vibration--Road Surface Profiles--Reporting of Measured Data, International Organization for Standardization, 1995.
[20] C. Arana, Control of Series Active Variable Geometry Suspensions, in, Ph. D. thesis, Imperial College London, London, 2016.
[21] R. Sharp, Testing and improving a tyre shear force computation algorithm, Vehicle System Dynamics, 41 (2004) 223-247.
[22] R. Sharp, M. Bettella, Shear Force and Moment Descriptions by Normalisation of Parameters and the “Magic Formula”, Vehicle system dynamics, 39 (2003) 27-56.
[23] M. Green, D. LIMEBEER, Linear robust control.[Sl]: Courier Corporation, 2012, Citado na,  40.
[24] M. Montazeri-Gh, M. Soleymani, Genetic optimization of a fuzzy active suspension system based on human sensitivity to the transmitted vibrations, Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 222 (2008) 1769-1780.
[25] T. Feyzi, M. Esfahanian, R. Tikani, S. Ziaei Rad, Simulation of the dynamic behavior of the magneto-rheological engine mount for automotive applications, Automotive Science and Engineering, 1 (2011) 1-5.
[26] R. Tikani, S. Ziaei-Rad, M. Esfahanian, Simulation and experimental evaluation of a magneto-rheological hydraulic engine mount, Modares Mechanical Engineering, 14 (2015).
[27] J. Marzbanrad, S. Ebrahimi-Nejad, G. Shaghaghi, M. Boreiry, Nonlinear vibration analysis of piezoelectric functionally graded nanobeam exposed to combined hygro-magneto-electro-thermo-mechanical loading, Materials Research Express, 5 (2018) 075022.
[28] S. Ebrahimi-Nejad, A. Karimyan, Vibration Analysis of Tire Treadband, Journal of Automotive and Applied Mechanics, 4 (2016) 10-14.
[29] H. Taei, M. Mirshams, M. Ghobadi, D. Vahid, H. Haghi, Optimal Control of a Tri-axial Spacecraft Simulator Test bed Actuated by Reaction Wheels, Journal of Space Science and Technology, 8 (2016) 35-44.
[30] M. Mirshams, H. Taei, M. Ghobadi, H. Haghi, Spacecraft attitude dynamics simulator actuated by cold gas propulsion system, Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 229 (2015) 1510-1530.
[31] F. Haugen, The Good Gain method for PI (D) controller tuning, Tech Teach, (2010) 1-7.
[32] H. Du, N. Zhang, Fuzzy control for nonlinear uncertain electrohydraulic active suspensions with input constraint, IEEE Transactions on Fuzzy systems, 17 (2008) 343-356.
[33] H. Nazemian, M. Masih-Tehrani, Hybrid Fuzzy-PID Control Development for a Truck Air Suspension System, SAE International Journal of Commercial Vehicles, 13 (2020) 55-70.
[34] M. Mollajafari, H.S. Shahhoseini, Cost-Optimized GA-Based Heuristic for Scheduling Time-Constrained Workflow Applications in Infrastructure Clouds Using an Innovative Feasibility-Assured Decoding Mechanism, J. Inf. Sci. Eng., 32 (2016) 1541-1560.