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Advanced Hydraulic Systems for Active Vibration Damping and Forklift Function to Improve Operator Comfort and Machine Productivity of Next Generation of Skid Steer Loaders
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 27, 2016 by SAE International in United States
Annotation ability available
Mobile Earth Moving Machinery like Skid-steer loaders have tight turning radius in limited spaces due to a short wheelbase which prevents the use of suspensions in these vehicles. The absence of a suspension system exposes the vehicle to ground vibrations of high magnitude and low frequency. Vibrations reduce operator comfort, productivity and life of components. Along with vibrations, the machine productivity is also hampered by material spillage which is caused by the tilting of the bucket due to the extension of the boom. The first part of the paper focuses on vibration damping. The chassis’ vibrations are reduced by the use of an active suspension element which is the hydraulic boom cylinder which is equivalent to a spring-damper. With this objective, a linear model for the skid steer loader is developed and a state feedback control law is implemented. The paper discusses the development of a Linear Quadratic Regulator (LQR) based compensator to obtain the feedback gains for this linear system with a quadratic cost function. It also discusses the methodology to select the LQR weights to penalize the state error and the input in order to minimize the cost function. The second part of the paper concentrates on the development of a robust path-planning control algorithm which adapts to the position of the boom to maintain a level load to achieve forklift function. The control algorithm comprises of three cascaded loops which act to keep the bucket horizontal. These cascaded loops encompass the feedback of parameters like boom angular position, ground inclination, bucket angular position and bucket pump swash plate position. The paper discusses the measurement setup on a skid steer loader in order to carry out experimental validation of the control algorithms. The experiments performed show about 29 % reduction in vibrations of the skid steer loader at low speed and 25 % reduction in vibrations at high speed. This proves that the controller is effective over wide range of speeds. The experimental results for the forklift function show that the bucket tracks the reference angle very well in order to achieve the forklift function. Thus, this paper discusses control strategies to tackle two major challenges of the skid steer loader related to operator comfort and machine productivity i.e. vibration damping and forklift function.
CitationOrpe, M. and Ivantysynova, M., "Advanced Hydraulic Systems for Active Vibration Damping and Forklift Function to Improve Operator Comfort and Machine Productivity of Next Generation of Skid Steer Loaders," SAE Technical Paper 2016-01-8116, 2016, https://doi.org/10.4271/2016-01-8116.
- Dix, Peter J., Lin Hong-Chin, Felsing Brian E., Bateman Troy D., Lamela Anthony J., and Shore Daniel B.. "Skid steer vehicle having suspensions that are locked based on vehicle speed." U.S. Patent 6,634,445, issued October 21, 2003.
- Berger, Alan D., and Patel Ketan B.. "Electronic ride control system for off-road vehicles." U.S. Patent 5,897,287, issued April 27, 1999.
- Latour, Chr, and Biener R.. "Comparison of active and passive oscillation suppression systems for wheel loaders. 3." In IFK (3rd Int. Fluid Power Conference), vol. 4, pp. 101-112. 2002.
- Latour, Ch, and Biener R.. "STEUERUNGEN UND REGELUNGEN-Schwingungstilgung in Radladern-Vergleich von aktiven und passiven Systemen." Olhydraulik und Pneumatik 47, no. 3 (2003): 171-174.
- Cristofori, Davide, Vacca Andrea, and Ariyur Kartik. "A novel pressure-feedback based adaptive control method to damp instabilities in hydraulic machines." SAE international journal of commercial vehicles 5, no. 2 (2012): 586-596.
- Sun, Weichao, Gao Huijun, and Yao Bin. "Adaptive robust vibration control of full-car active suspensions with electrohydraulic actuators." Control Systems Technology, IEEE Transactions on 21, no. 6 (2013): 2417-2422.
- Ivantysynova, Monika, Rahmfeld Robert, Lautner Erik, and Weber Jurgen. "Hydraulic system for linear drives controlled by a displacer element." U.S. Patent 7,543,449, issued June 9, 2009.
- Rahmfeld, R., and Ivantysynova M.. "New Displacement Controlled Linear Actuator Technology-a Suitable Control Element for Active Oscillation Damping." In The 8th Scandinavian Inter-national Conference on Fluid Power (SICFP'03), pp. 1139-1154. 2003.
- Eggers, Bastian, Rahmfeld Robert and Ivantysynova Monika. "An energetic comparison between valveless and valve controlled active vibration damping for off-road vehicles." In Proceedings of the JFPS International Symposium on Fluid Power, vol. 2005, no. 6, pp. 275-283. The Japan Fluid Power System Society, 2005.
- Williamson, C. "Active Vibration Damping for a Skid-Steer Loader Using Displacement-Controlled Actuators." PhD diss., PhD thesis, Purdue University, 2007.
- Williamson, Christopher, Lee Shinok, and Ivantysynova Monika. "Active vibration damping for an off-road vehicle with displacement controlled actuators." International Journal of Fluid Power 10, no. 3 (2009): 5-16.
- Lee, Shinok. "Controller design and measurement for active vibration damping of skid-steer loader via displacement controlled actuators." (2010).
- "Hydraulic self-leveling control for boom and bucket." U.S. Patent 3,563,137, issued February 16, 1971.
- Fryk, Bruce K. "Bucket leveling system with dual fluid supply." U.S. Patent 4,923,362, issued May 8, 1990.
- Geyler Arthur H. Jr, "Hydraulic system for bucket self-leveling during raising and lowering of boom." U.S. Patent 5,447,094, issued September 5, 1995.
- Wykhuis, Lloyd A., and O'neill Michael J.. "Lift arm and control linkage structure for loader buckets." U.S. Patent 4,355,946, issued October 26, 1982.
- Sagaser, Thomas M. "Electronic bucket positioning and control system." U.S. Patent 4,844,685, issued July 4, 1989.
- Kauss, Wolfgang. "Hydraulic control system for mobile equipment." U.S. Patent 7,621,711, issued November 24, 2009.
- Gillespie, Thomas D. "Fundamentals of Vehicle Dynamics. Warrendale, PA: Society of Automotive Engineers." (1992): 195-236.
- Bryson, A., and Ho Y.. "Applied Optimal ControlHemisphere Publishing."New York (1975).
- Murray, Richard M. "Optimization-based control." California Institute of Technology, CA (2009).
- Busquets, E. and Ivantysynova, M., "Adaptive Robust Motion Control of an Excavator Hydraulic Hybrid Swing Drive," SAE Int. J. Commer. Veh. 8(2):568-582, 2015, doi:10.4271/2015-01-2853.
- Rahmfeld, R. "Development and control of energy saving hydraulic servo driven for mobile machine." Hamburg: Technischen Universitaet Hamburg-Harburg (2002).
- Grabbel, Jörg. Robust Control Strategies for Displacement Controlled Rotary Actuators Using Vane Type Motors. VDI-Verlag, 2004.
- Hippalgaonkar, R. (2014). Power management strategies for hydraulic hybrid multi-actuator mobile machines with DC actuators. West Lafayette: Purdue University.
- Martínez Jorge L., Mandow Anthony, Morales Jesús, Pedraza Salvador, and García-Cerezo Alfonso. "Approximating kinematics for tracked mobile robots." The International Journal of Robotics Research 24, no. 10 (2005): 867-878.
- Ivantysynova, M., "Displacement Controlled Linear and Rotary Drives for Mobile Machines with Automatic Motion Control," SAE Technical Paper 2000-01-2562, 2000, doi:10.4271/2000-01-2562.