Publications in peer-reviewed or refereed journals

1. Becker, C.M. and Els, P.S., 2014, Profiling of rough terrain, International Journal of Vehicle Design, Vol. 64, Nos. 2/3/4, pp. 240-261.

 

1. Thoresson, M.J., Botha, T.R. and Els, P.S., 2014, The relationship between vehicle yaw acceleration response and steering velocity for steering control, International Journal of Vehicle Design, Vol. 64, Nos. 2/3/4, pp. 195-213.

 

1. Van Der Westhuizen, S.F. and Els, P.S., 2013, Slow active suspension control for rollover prevention, Journal of Terramechanics, Vol. 50, 2013, pp.29-36.

 

1. Nolte, K., Krüger, P.E., Els, P.S. and Nolte, H., 2013, Three dimensional musculoskeletal modelling of the abdominal crunch resistance training exercise, Journal of Sports Sciences, Vol. 31, No. 3, pp. 264 - 275.

 

1. Kat, C. and Els, P.S., 2012, Validation metric based on relative error, Mathematical and Computer modelling of Dynamical Systems, Vol. 18, No. 6, October 2012, pp. 487-520.

 

       6.   Kat, C. and Els, P.S., 2011, Elasto-plastic leaf spring model, International Journal of                                     Engineering Systems Modeling and Simulation, Vol. 3, Nos. 3/4, 2011.

 

1. Breytenbach, H.G.A. and Els, P.S., 2011, Optimal vehicle suspension characteristics for increased structural fatigue life, Journal of Terramechanics, Vol. 48, pp. 397-408

 

       8.   Nolte, K., Krüger, E.P. and Els, P.S., 2011, Three dimensional musculoskeletal modelling of                     the seated biceps curl resistance training exercise focusing on the biomechanical and                              anthropometric considerations of the end-user, Sports Biomechanics, Vol. 10, Issue 2, pp.146-                160.

 

        9. Cronje, P.H. and Els, P.S., 2010, Improving off-road vehicle handling using an active anti-roll bar,             Journal of Terramechanics, Vol. 47, pp. 179-189.

 

     10. Thoresson, M.J., Uys, P.E., Els, P.S. and Snyman, J.A., 2009, Efficient optimisation of a vehicle                 suspension system, using a gradient-based approximation method. Part 1. Mathematical                         modeling, Mathematical and Computer Modeling, Vol. 50, pp. 1421-1436.

 

11. Thoresson, M.J., Uys, P.E., Els, P.S. and Snyman, J.A., 2009, Efficient optimisation of a vehicle suspension system, using a gradient-based approximation method. Part 2. Optimisation results, Mathematical and Computer Modeling, Vol. 50, pp. 1437-1447.

 

12. Kat, C. and Els, P.S., 2009, Interconnected air spring model, Mathematical and Computer Modeling of Dynamical Systems, Vol. 15, No. 4, August 2009, pp. 353–370.

 

13. De Wet, G.J., Steyn, J.L. and Els, P.S., 2008, Simulation and experimental verification of solenoid valve characteristics for semi-active damper, International Journal of Vehicle Design, Vol. 47, Nos. 1/2/3/4.

 

14. Els, P.S., Theron, N.J., Uys, P.E. and Thoresson, M.J., 2007, The Ride Comfort vs. Handling Compromise for Off-Road Vehicles, Journal of Terramechanics, Vol. 44, pp. 303–317.

 

15. Theron, N.J.  and Els, P.S., 2007, Modeling of a semi-active hydropneumatic spring-damper unit, International Journal of Vehicle Design, Vol. 45, No. 4, pp. 501-521.

 

16. Uys, P.E., Els, P.S. and Thoresson, M.J., 2007, Suspension settings for optimal ride comfort of off-road vehicles travelling on roads with different roughness and speeds, Journal of Terramechanics, Vol. 44, pp. 163-175.

 

17. Uys, P.E., Els, P.S., Thoresson, M.J., Voigt, K.G. and Combrinck, W.C., 2006, Experimental determination of moments of inertia for an off-road vehicle in a regular engineering laboratory, The International Journal of Mechanical Engineering Education, Vol. 34, No. 4, pp. 291-314.

 

18. Els, P.S., Uys, P.E., Snyman, J.A. and Thoresson, M.J., 2006, Gradient-based approximation methods applied to the optimal design of vehicle suspension systems using computational models with severe inherent noise, Mathematical and Computer Modeling, Vol. 43, pp. 787-801.

 

19. Misselhorn, W.E., Theron, N.J. and Els, P.S., 2006 Investigation of hardware-in-the-loop for use in suspension development, Vehicle System Dynamics, Vol. 44, No. 1, pp. 65-81.

 

20. Uys, P.E., Els, P.S. and Thoresson, M.J., 2006, Criteria for Handling Measurement, Journal of Terramechanics, Vol. 43, pp. 43-67.

 

21. Els, P.S., 2005, The Applicability of Ride Comfort Standards to Off-Road Vehicles, Journal of Terramechanics, Vol. 42, pp. 47-64.

 

22. Giliomee, C.L., Els, P.S. and Van Niekerk, J.L., 2005, Anelastic Model of a Twin Accumulator Hydro-pneumatic Suspension System, R & D Journal, July 2005, pp. 11-17.

 

23. Els, P.S. and Uys, P.E., 2003, Investigation of the Applicability of the Dynamic-Q Optimisation Algorithm to Vehicle Suspension Design, Mathematical and Computer Modeling, Vol. 37, pp. 1029-1046.

 

24. Janse van Rensburg, N., Steyn, J.L. and Els, P.S., 2002, Time delay in a semi-active damper: Modeling the bypass valve, Journal of Terramechanics, Vol. 39, pp 35-45.

 

25. Els, P.S. and Grobbelaar, B., 1999, Heat Transfer Effects on Hydropneumatic Suspension Systems, Journal of Terramechanics, Vol. 36, pp. 197-205.

 

26. Els, P.S. and Holman, T.J., 1999, Semi-Active Rotary Damper for a Heavy Off-Road Wheeled Vehicle, Journal of Terramechanics, Vol. 36, pp. 51-60.

 

27. Giliomee, C.L. and Els, P.S., 1998, Semi-Active Hydropneumatic Spring and Damper System, Journal of Terramechanics, Vol. 35, pp. 109-117.

 

28. Els, P.S. and Grobbelaar, B. 1993, Investigation of the Time- and Temperature Dependency of Hydropneumatic Suspension Systems, SAE Technical Paper Series no. 930265, Published in Vehicle Suspension and Steering Systems, SAE Special Publication SP-256, pp. 55-65.

 

 

Published full-length conference papers

1.     Hamersma, H.A. and Els, P.S., The Development of a Longitudinal Control System for a Sports-Utility-Vehicle, Proceedings of the ASME IDETC/CIE 2013.

2.     Kolansky, J., Sandu, C., Botha, T.R. and Els, P.S., Real-Time Vehicle Parameters Estimation, Proceedings of the ASME IDETC/CIE 2013.

3.     Kat, C., Johrendt, J.L. and Els, P.S., 2012, Computational Efficiency and Accuracy Comparison Of Leaf Spring Modelling Techniques, Proceedings of the ASME IDETC/CIE Conference, Chicago, 12 to 15 August 2012.

4.     Strydom, A, Els, P.S. and Kaul, S., 2012, Magneto-rheological (MR) Damper Modeling for Semi-active Control without Force Feedback, Proceedings of the ASME IDETC/CIE Conference, Chicago, 12 to 15 August 2012.

5.     Botha, T.R. and Els, P.S., 2012,Vehicle Sideslip Estimation Using Unscented Kalman Filter, AHRS and GPS, Proceedings of the ASME IDETC/CIE Conference, Chicago, 12 to 15 August  2012.

6.     Botha, T.R. and Els, P.S., 2012, Road Friction Estimation using Stereography, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

7.     Strydom, A and Els, P.S., 2012, Model Validation of Mini-Baja Vehicle, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

8.     Hamersma, H.A. and Els, P.S., 2012, A Multi-body Longitudinal Dynamics Model of a Sports Utility vehicle, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

9.     Becker, C.M. and Els, P.S., 2012, Wheel Force Transducer Measurements on a Vehicle in Transit, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

10. Faure, D., Theron, N.J. and Els, P.S., 2012, Vehicle Rollover Prevention using Rear Wheel Steering Control, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

11. Kat, C. and Els, P.S., 2012, Effect of Hysteresis in Steel Leaf Springs on Ride and Suspension Forces – Preliminary Study, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

12. Stallmann, J. and Els, P.S., 2012, Validation of Mathematical Tyre Models used in Vertical Vehicle Dynamics Simulations, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

13. Botha, T.R., Els, P.S. and Becker, C.M., 2012, Measuring Tyre Contact Patch Deformation using Stereography, Proceedings of the 12^th European Regional Conference of the ISTVS, Pretoria, South Africa, 24 to 28 September 2012 (peer reviewed).

14. Botha, T.R. and Els, P.S., 2012, High Speed Autonomous Off-Road Vehicle Steering, 8^th South African Conference on Computational and Applied Mechanics, 3-5 September 2012, Johannesburg, South Africa.

15. Strydom, A. and Els, P.S., 2012, Semi-Active Suspension Control of an Off-Road Vehicle for Ride Comfort Optimization, 8^th South African Conference on Computational and Applied Mechanics, 3-5 September 2012, Johannesburg, South Africa.

16. Kat, C. and Els, P.S., 2011, Importance of Correct Validation of Simulation Models, Proceedings of the ASME IDETC/CIE 2011, Washington, DC, 28 to 31 August 2011 (peer reviewed).

 

17. Botha, T.R. and Els, P.S., 2011, Profile optimisation of table top speed hump for speed control, Proceedings of the ASME IDETC/CIE 2011, Washington, DC, 28 to 31 August 2011 (peer reviewed).

 

18. Els, P.S. and Becker, C.M., 2011, Characterisation of off-road tyres, Proceedings of the 17^th International Conference of the ISTVS, Blacksburg, USA, 18 to 22 September 2011 (peer reviewed).

 

19. Botha, T.R. and Els, P.S., 2011, High speed autonomous off-road vehicle steering, Proceedings of the 17^th International Conference of the ISTVS, Blacksburg, USA, 18 to 22 September 2011 (peer reviewed).

 

20. Van Der Westhuizen, S.F. and Els, P.S., 2011, Slow active suspension control for rollover prevention, Proceedings of the 17^th International Conference of the ISTVS, Blacksburg, USA, 18 to 22 September 2011 (peer reviewed, received “Best paper award” in the “Vehicle Dynamics, Mobility and Safety” session).

 

21. Kat, C. and Els, P.S., 2011, Leaf spring modelling, Proceedings of the 17^th International Conference of the ISTVS, Blacksburg, USA, 18 to 22 September 2011 (peer reviewed).

 

22. Becker, C.M. and Els, P.S., 2011, Modal analysis on a large off-road tyre using Scanning Laser Vibrometry, Proceedings of the 17^th International Conference of the ISTVS, Blacksburg, USA, 18 to 22 September 2011 (peer reviewed).

 

23. Breytenbach, H.G.A., Cronje, P.H. and Els, P.S., 2010, Effects of Suspension Friction on Off-road Vehicle Dynamics, Proceedings of the Joint 9th Asia-Pacific ISTVS Conference and Annual Meeting of the Japanese Society for Terramechanics, 27 to 30 September 2010, Sapporo, Japan.

 

24. Kat, C. and Els, P.S., 2010, Leaf spring model based on material behaviour, Proceedings of the Joint 9th Asia-Pacific ISTVS Conference and Annual Meeting of the Japanese Society for Terramechanics, 27 to 30 September 2010, Sapporo, Japan.

 

25. Becker, C.M. and Els, P.S., 2010, Profiling of Rough Terrain, Proceedings of the Joint 9th Asia-Pacific ISTVS Conference and Annual Meeting of the Japanese Society for Terramechanics, 27 to 30 September 2010, Sapporo, Japan.

 

26. Els, P.S. and Becker, C.M., 2010, Characterisation and Modeling of Off-road Tyres, Proceedings of the Joint 9th Asia-Pacific ISTVS Conference and Annual Meeting of the Japanese Society for Terramechanics, 27 to 30 September 2010, Sapporo, Japan.

 

27. Botha, T.R. and Els, P.S., 2010, High Speed Autonomous Off-Road Vehicle Steering, Proceedings of the Joint 9th Asia-Pacific ISTVS Conference and Annual Meeting of the Japanese Society for Terramechanics, 27 to 30 September 2010, Sapporo, Japan.

 

28. Els, P.S. and Theron, N.J., 2009, The Four-State Semi-active Suspension System (4S₄), Proceedings of the 11^th European Regional Conference of the International Society for Terrain Vehicle Systems (ISTVS), 5 to 8 October 2009, Bremen, Germany.

 

29. Els, P.S. and Becker, C.M., Profiling of rough terrain, 2009, Proceedings of the 11^th European Regional Conference of the International Society for Terrain Vehicle Systems (ISTVS), 5 to 8 October 2009, Bremen, Germany.

 

30. Kat, C. and Els, P.S., 2009, Suspension forces on a tri-axle air-suspended semi-trailer, Proceedings of the 11^th European Regional Conference of the International Society for Terrain Vehicle Systems (ISTVS), 5 to 8 October 2009, Bremen, Germany.

 

31. Breytenbach, H.G.A. and Els, P.S., 2009, Off-road vehicle suspension optimisation for increased structural fatigue life, Proceedings of the 11^th European Regional Conference of the International Society for Terrain Vehicle Systems (ISTVS), 5 to 8 October 2009, Bremen, Germany. (received the “best presentation award” at the conference)

 

32. Els, P.S., Uys. P.E., Thoresson, M.J. and Snyman, J.A., 2004, Obtaining Vehicle Spring and Damper Characteristics for Improved Ride Comfort and Handling, using Mathematical Optimization. 18th IAVSD Symposium. Japan August 2004. Poster presentation, #07. Extended summaries p 276-277.

 

33. Uys, P.E., Els, P.S. and Thoresson, M.J., 2003, Validation of Handling Criteria, Proceedings of the 9th European Conference of the International Society for Terrain Vehicle Systems (ISTVS), Harper Adams, UK, 8-11 September, pp 532-553.

 

34. Theron, N.J. and Els, P.S., 2003, Modeling of a semi-active hydropneumatic spring-damper system, Proceedings of the 9th European Conference of the International Society for Terrain Vehicle Systems (ISTVS), Harper Adams, UK, 8-11 September, pp 504-515.

34.

35. Els, P.S. and Van Niekerk, J.L., 1999, Dynamic Modeling of an Off-Road Vehicle for the Design of a Semi-Active, Hydropneumatic Spring-Damper System, Proceedings of the 16th International Association for Vehicle System Dynamics (IAVSD) Symposium: Dynamics of Vehicles on roads and Tracks, Pretoria, South Africa, August 30 to September 3.

 

36. Els, P.S., 1999, The Applicability of Ride Comfort Standards to Off-Road Vehicles, Proceedings of the Human Response to Vibration, 34th Meeting of the UK Group, Ford Motor Company Limited, Dunton, Essex, UK, 22-24 September.

 

37. Els, P.S. and Nell, S., 1999, Comparison Between Subjective and Objective Ride Comfort for Military Off-Road Vehicles , Proceedings of the 13th International Conference of the ISTVS, 14-17 September 1999, Munich, Germany.

 

38. Els, P.S. and Grobbelaar, B., 1997, Heat Transfer Effects on Hydropneumatic Suspension Systems, In Proceedings of the 7th European ISTVS Conference, 8-10 October, Ferrara, Italy,  pp. 235-242.

 

39. Els, P.S. and Holman, T.J., 1997, Semi-Active Rotary Damper for a Heavy Off-Road Wheeled Vehicle, In Proceedings of the 7th European ISTVS Conference, 8-10 October, Ferrara, Italy, pp. 259-266.

 

40. Giliomee, C.L. and Els, P.S., 1997, Semi-Active Hydropneumatic Spring and Damper System, In Proceedings of the 7th European ISTVS Conference, 8-10 October 1997, Ferrara, Italy, pp. 441-448.