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A transformation of agriculture reached commercial reality at the beginning of this century as automated steering of agricultural machine systems increased the productivity and convenience in crop production systems. Following guidance, additional technologies have resulted in increasing optimized machine productivity. Today, integrated worksite solutions through machine and information management continues to transform agriculture. This is the precursor to autonomous worksite solutions that lead to the optimization of the worksite ecosystem. This paper will review the progress from the perspective of the customer value provided by increasing automated systems and the industry execution of autonomous driving technologies and will enable the pathways to autonomous worksites.

From 1998 through 2002, the Steel And Foam Energy Reduction (SAFER) Barrier was developed, tested, and evaluated for use in high-speed racetrack applications in order to decrease the severity of high-energy crashes into the outer, rigid containment walls. The original SAFER Barrier was first installed at the Indianapolis Motor Speedway (IMS) and used at the 2002 INDY 500 mile race. Following the successful implementation of the original SAFER Barrier system, further efforts were directed toward improving the barrier's design and adapting the system to smaller-radius, high-speed racetracks. The continued research and development effort resulted in the second generation of the SAFER barrier, also known as SAFER Barrier - Version 2. Following the development of the SAFER Barrier - Version 2, it was also determined that a need existed to design an opening or gate within the SAFER Barrier System.

In recent years, high-speed oval track racing has become one of the most popular sports in the country, especially with regards to the NASCAR and Indy Racing Leagues. In general, typical oval track raceways have used reinforced concrete outer walls for containment of the high-speed race cars. While these concrete walls provide effective containment of errant vehicles, their rigidity has led to many serious injuries and fatalities. Recently, an energy-absorbing barrier was developed by the Midwest Roadside Safety Facility at the University of Nebraska - Lincoln to mitigate the severity of impacts with the outer containment walls. The new barrier, known as the Steel And Foam Energy Reduction (SAFER) Barrier, consists of a high-strength, tubular steel skin that distributes the impact load to energy-absorbing foam cartridges in order to reduce the severity of the impact, extend the impact event, and provide the occupant of the race car additional protection.

This paper presents system identification methods of using both frequency and time domain analyses to estimate system parameters for a nonlinear electrohydraulic (E/H) tractor steering system. The frequency domain method identified parameters of the system using a linear model with a nonlinear gain function. The time domain method identified those parameters using a discrete time expression. A method of multiple models was used to represent the nonlinear system for both frequency and time domain analyses. Simulation and test results showed that the modified identification method could satisfactorily identify the parameters of the nonlinear E/H tractor steering system.