Warinner, D., Sailor, E., Szabela, W., and Sherwin, K., "Hybrid Electric Vehicle Steering System," SAE Technical Paper 2005-01-3533, 2005, doi:10.4271/2005-01-3533.
The 4200 Hybrid Electric Vehicle is a Class 5-6 medium duty chassis usable in a variety of short range applications. The vision for this vehicle concept is a self contained hybrid diesel-electric vehicle with range and performance similar to a diesel-only vehicle along with improved fuel efficiency. The hydraulic steering system is an ideal candidate for energy savings due to its continuously running on-engine pump component.Electrically powered hydraulic steering (EPHS) pumps, along with a Column Drive electric assist unit, replace the conventional engine driven pump. The Column Drive masks any switching transients in the flow from the EPHS units and provides steering feel tuning. The system offers the benefits of improved on-center handling, increased returnability, speed proportional assist, and cross-wind compensation.