ON PERFORMANCE OPTIMIZATION AND DIGITAL CONTROL OF HYDROSTATIC DRIVES FOR VEHICLE APPLICATIONS

Today, hydrostatic transmissions and digital controllers are becoming commonly used devices in vehicle propulsion systems. Computer based methods to solve the design problems associated with such systems are also relatively well established. However, in most cases very simplified models are used especially for the hydrostatic units. In this thesis emphasis is put on a more detailed description of the real characteristics of a straight hydrostatic transmission. A mathematical model for losses in variable hydrostatic pumps and motors is developed. This model has then been used to optimize the performances of hydrostatic drives for on-the-road vehicles. To carry out performance optimization a computer program written in FORTRAN has been created, including the complex optimization method. Using this program the influence of transmission ratios and prime mover speeds on the overall efficiency of a simple hydrostatic drive has been investigated. Another system which has been investigated with respect to performance optimization is the hybrid transimission in the Volvo city bus. This system consists of an engine, a hydrostatic transmission and a flywheel used as an energy storage device. The role of microcomputers in fluid power control and especially in closed-loop control of hydrostatic transmissions is discussed. A strategy for digital closed-loop pressure control of hydrostatic transmissions for vehicle applications is presented. It is also demonstrated how dynamic simulation technics can be used to design a digital control system for a hydrostatic drive. The investigated system in this case is the Volvo bus transmission. Both theoretical and experimental results are presented. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9173726699
• Corporate Authors:

  Linkoeping University of Technology

  Pneumatik
  Linkoeping,   Sweden 
• Authors:
  • Rydberg, K-E
• Publication Date: 1983

Media Info

• Features: Figures; Photos; References;
• Pagination: 198 p.
• Serial:
  • Issue Number: 99

Subject/Index Terms

• TRT Terms: Automated vehicle control; Automatic transmissions; Buses; Computer programs; Digital computers; Energy storage systems; Flywheels; Hydrostatics; Loss and damage; Mathematical models; Microcomputers; Optimization; Propulsion; Theses; Transmissions; Vehicle power plants
• Uncontrolled Terms: Controllers; Dissertation; Micro; Propulsion systems
• Old TRIS Terms: Digital systems
• ITRD Terms: 1272: Bus; 8673: Digital computer; 1324: Flywheel; 5403: Hydrostatic; 9040: Loss; 6473: Mathematical model; 9045: Micro; 8645: Software; 8597: Thesis; 1333: Transmission (veh)
• Subject Areas: Energy; Highways; Public Transportation; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00382195
• Record Type: Publication
• Source Agency: Swedish National Road and Transport Research Institute (VTI)
• ISBN: 91-7372-669-9
• Report/Paper Numbers: Monograph
• Files: ITRD, TRIS
• Created Date: Apr 30 1984 12:00AM