Abstract: A towed scraper control system automatically lowers the scraper blade to a working position at the start of a scraping operation according to a certain method. The method includes sensing a ground speed of the vehicle and sensing a draft force applied by the scraper to the vehicle. With the vehicle pulling the scraper at or near a target ground speed over terrain with the blade positioned above a surface of the ground, the blade is automatically lowered with respect to the scraper frame at a first rate until the blade begins to engage the surface of the ground. Thereafter, while the vehicle continues to move forward at or near the target ground speed, the blade is lowered with respect to the frame at a second rate and for a duration related to the sensed ground speed so that lowering of the blade stops when the scraper wheel begins to enter a cut produced by the blade.

Abstract: A method is provided for automatically determining a hitch raise rate calibration value for a hitch control system having a hydraulic actuator for moving the hitch, a valve for controlling flow of hydraulic fluid to the actuator and an electronic hitch control unit. The method includes applying a first control signal to the valve to cause the hitch to raise, determining a first hitch velocity as the hitch moves in response to the first control signal, and repeating these steps for a second control signal. The raise rate calibration value is then calculated as a function of a desired raise velocity, the first and second control signals and the first and second velocities.

Abstract: A vehicle/implement hitch control system is responsive to a wheel slip signal indicative of the slippage of the driven wheels of the vehicle. The control system generates an integrated slip signal using an integration function, generates a proportional slip signal using a proportional function, and generates a combined slip signal as a combination of the integrated slip signal and the proportional slip signal. An operator-controllable slip response adjuster generates slip response signals. A hitch control signal is generated as a function of the slip response signal and the combined slip signal, so that the operator can vary the response of the hitch control signal to the integrated slip signal, to a mixture of the integrated slip signal, and to various multiples of the proportional slip signal only.