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Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering

First Advisor

Ralph Alcock


Two steering systems, an electrically powered steering system (EPS) and a hydraulically power assisted steering system (HP AS), were developed for Electri-Load, a rear wheel steer electric loader vehicle designed and built at the Agricultural Engineering Department of South Dakota State University. The EPS system utilized two linear actuators and an electronic control unit which received inputs from the steering wheel and the steered wheels to determine the relative steering angle. This system required 0.58 kW of power, which was insufficient at times. The HP AS system consisted of a priority valve, steering control unit, mechanical linkage and hydraulic steering cylinder. The 'hydraulic system required an estimated 4.32 kW of power, a large increase over the EPS system. However, the steering tests on the sinusoidal track found that the HP AS system was significantly better in terms of accuracy and ease of control than the EPS system.

Library of Congress Subject Headings

Electric vehicles -- Steering-gear
Steering-gear -- Design and construction
Loaders (Machines)
Industrial electric trucks



Number of Pages



South Dakota State University