Steering 3n2u73

Design and development of a modern steering system influences vehicle response, driver controllability, comfort, safety and fuel economy. In this interactive se minar, participants will analyze the steering system, from the steering wheel to the road wheel. The seminar will cover the anatomy and architecture of the lowe r steering system (wheel end suspension geometry, linkages and steering gear), i ts effect on vehicle response, and how a force at the patch is translate d to a torque in the steering wheel. The anatomy and architecture of the upper s teering system (steering column and intermediate shaft), including the topic of non-uniformity and the role of the upper steering in the occupant protection sys tem will also be explored. Significant time will be devoted to the generation of power assist, either by wa y of a conventional hydraulic power steering (HPS) or electrically power assiste d steering (EPAS). Topics include system anatomy/architecture as well as the eff ect of the system on fuel economy. The seminar will finish with a discussion of common steering objective tests and how the kinematics, compliances, friction an d power assist affect steering response and torque . Students will have the opportunity to participate in exercises throughout the seminar, culminating in a final project where they will calculate an assist curve for both a HPS and an EPAS system. This course has been approved by the Accreditation Commission for Traffic Accide nt Reconstruction (ACTAR) for 12 Continuing Education Units (CEUs). Upon complet ion of this seminar, accredited reconstructionists should ACTAR, 800-809 -3818, to request CEUs. As an ACTAR approved course, the fee for CEUs is reduced to $5.00. Learning Objectives By attending this seminar, you will be able to: Identify common steering and suspension system architectures Compare and contrast different types of steering gears Describe the function of the steering column and intermediate shaft subsystem Describe the influence of system tuning on steering response and torque Compare and contrast different types of power assist systems Describe the effect of power steering on fuel economy Calculate important parameters that affect steering response and torque Who Should Attend This seminar is designed for automotive engineers in the vehicle dynamics, chass is, suspension, steering and chassis controls fields who work in product design, development, testing, simulation or research. Prerequisites Participants must have a working knowledge of the fundamentals of vehicle dynami cs acquired through sufficient work experience or by participating in seminars s uch as SAE's Vehicle Dynamics for enger Cars and Light Trucks (ID# 99020), C hassis and Suspension Component Design for enger Cars and Light Trucks (ID# 95025) or Advanced Vehicle Dynamics for enger Cars and Light Trucks (ID# C04 15). Topical Outline DAY ONE Introduction Elements of the steering system Coordinate systems The Lower Steering System Kingpin axis -- Front versus rear steer; Caster angle and kingpin inclination; C aster trail and scrub radius; Steer arm Class exercise - Calculate moment about the kingpin axis for cornering and parki

ng loadcases Linkages/steering geometry -- Rack and pinion; Haltenberger; Parallel linkage Steering gear anatomy and architecture -- Rack and pinion; Recirculating ball Friction and compliances Class exercise - Calculate pinion torque for cornering and parking loadcases The Upper Steering System (steering column & intermediate shaft) Anatomy and architecture Non-uniformity Sources of friction and torsional compliance Role of the upper steering system in the occupant protection system DAY TWO Power Assist Systems Conventional hydraulic power assist Electro-hydraulic assist Electric power assisted steering Speed sensitive steering Vehicle Level Considerations Steering response -- Effect of steering ratio on response gain Steering feel/torque -- Common steering tests and metrics; Effect of fr iction, compliances, and steering column non-uniformity Class exercise - Calculate a power steering assist curve for hydraulic or electr ic power assisted steering system Error states (nibble/wheelfight, pull/drift) Power steering system effect on fuel consumption