Abstract: A draft load control system for an agricultural tractor having electronic engine and draft load controllers interconnected by a digital communications bus over which parameters for engine load are made readily available to the draft load controller. The draft load control system is suitable for front-mounted, rear-mounted, or towed implements without requiring additional sensing equipment.

Abstract: A system and method for managing the power of an engine-powered vehicle is provided. The power of the engine is managed in automatic vehicle speed mode by inputting the desired vehicle ground speed and a measured variable to an electronic controller, which automatically up-shifts the transmission and reduces engine speed to maintain a desired vehicle speed and reduce fuel consumption when a load on the vehicle is reduced and down-shifts the transmission and increases engine speed when the load is applied.

Abstract: A draft load control system for a primary motive power source that uses hitch cylinder pressure to provide input to the control system of the draft load on the power source caused by a hitch-connected or a towed, ground-engaging implement.

Abstract: A theorem and method for determining the weight and center of gravity of a ground-engaging implement connected to a three-point hitch on an agricultural tractor or other prime mover using hitch cylinder pressure and hitch position as calibration inputs to a hitch control system.

Abstract: The control includes a fluid system having a fluid passage in connection with a rod end chamber and a piston end chamber of a fluid cylinder connected to the front axle and a front end of a vehicle and extendible in length for increasing a distance between the front axle and the front end, a progressive control valve is disposed in the passage and is controllably movable through a range of progressively more restrictive partially open positions. The valve can also have a one-way flow position to allow fluid flow only from the piston end chamber to the rod end chamber, to allow only retraction of the cylinder. A controller is automatically operable for causing the valve to move through the range of progressively more restrictive partially open positions as the fluid cylinder is increasingly extended, and for moving the valve to the one-way flow position when the cylinder reaches a predetermined length.

Abstract: A theorem and method for determining the weight and center of gravity of a ground-engaging implemented connected to a three-point hitch on an agricultural tractor or other prime mover using hitch cylinder pressure and hitch position as calibration inputs to a hitch control system.

Abstract: A draft load control system for a primary motive power source that uses hitch cylinder pressure to provide input to the control system of the draft load on the power source caused by a hitch-connected or a towed, ground-engaging implement.

Abstract: A draft load control system for an agricultural tractor having electronic engine and draft load controllers interconnected by a digital communications bus over which parameters for engine load are made readily available to the draft load controller. The draft load control system is suitable for front-mounted, rear-mounted, or towed implements without requiring additional sensing equipment.

Abstract: A control system and method for detecting variable load types and controlling the operation of a PTO clutch to effect engagement of the clutch with variable loads, and especially to more optimally effect the engagement of a clutch with a very light load or an associated over-running clutch is disclosed. The control system includes a controller that receives input and output clutch shaft speed signals and generates control signals to control the pressure applied by the clutch. If no appreciable engine droop is detected at the time of initial movement of the output clutch shaft, the load is considered to be of a very light load type, and a set of control signals based upon such load type designation, which control signals define a control curve that is flatter and more gentle than would otherwise be considered desirable, is thereafter applied to the clutch to effect engagement of the load.

Abstract: A control system and method for detecting variable load types and controlling the operation of a PTO clutch to effect engagement of the clutch with variable loads, and especially to more optimally effect the engagement of a clutch with a heavy load is disclosed. The control system includes a controller that receives input and output clutch shaft speed signals and generates control signals to control the pressure applied by the clutch. When heavier loads are applied to the PTO shaft, during the time when control signals are being generated before detection of initial movement of the output shaft, the controller generates one or more shock signals of short duration to cause momentary applications of significantly greater pressure to the clutch in order to break loose the applied load.

Abstract: The control includes a fluid system having a fluid passage in connection with a rod end chamber and a piston end chamber of a fluid cylinder connected to the front axle and a front end of a vehicle and extendible in length for increasing a distance between the front axle and the front end, a progressive control valve is disposed in the passage and is controllably movable through a range of progressively more restrictive partially open positions. The valve can also have a one-way flow position to allow fluid flow only from the piston end chamber to the rod end chamber, to allow only retraction of the cylinder. A controller is automatically operable for causing the valve to move through the range of progressively more restrictive partially open positions as the fluid cylinder is increasingly extended, and for moving the valve to the one-way flow position when the cylinder reaches a predetermined length.

Abstract: A PTO control system and method for engaging a PTO clutch of a vehicle or work machine such as, but not limited to, an agricultural tractor, that can effectively utilize both engine speed and PTO output speed values for determining a predicted and/or actual PTO load and other variable conditions which can effect engagement, and which can responsively calibrate the system for engagement under the load and other conditions and adaptively control applied acceleration and torque during the engagement.

Abstract: A control system and method for detecting variable load types and controlling the operation of a PTO clutch to effect engagement of the clutch with variable loads, and especially to more optimally effect the engagement of a clutch with a very light load or an associated over-running clutch is disclosed. The control system includes a controller that receives input and output clutch shaft speed signals and generates control signals to control the pressure applied by the clutch. If no appreciable engine droop is detected at the time of initial movement of the output clutch shaft, the load is considered to be of a very light load type, and a set of control signals based upon such load type designation, which control signals define a control curve that is flatter and more gentle than would otherwise be considered desirable, is thereafter applied to the clutch to effect engagement of the load.

Abstract: A control system and method for detecting variable load types and controlling the operation of a PTO clutch to effect engagement of the clutch with variable loads, and especially to more optimally effect the engagement of a clutch with a heavy load is disclosed. The control system includes a controller that receives input and output clutch shaft speed signals and generates control signals to control the pressure applied by the clutch. When heavier loads are applied to the PTO shaft, during the time when control signals are being generated before detection of initial movement of the output shaft, the controller generates one or more shock signals of short duration to cause momentary applications of significantly greater pressure to the clutch in order to break loose the applied load.

Abstract: A PTO control system and method for engaging a PTO clutch of a vehicle or work machine such as, but not limited to, an agricultural tractor, that can effectively utilize both engine speed and PTO output speed values for determining a predicted and/or actual PTO load and other variable conditions which can effect engagement, and which can responsively calibrate the system for engagement under the load and other conditions and adaptively control applied acceleration and torque during the engagement.

Abstract: A method for controlling clutch pressures during power shifts involving detecting clutch slippage, utilizing individual pressure control. In the shift, the pressure in the off-going clutch is ramped down over a time interval, for instance, an interval of from about 0.10 seconds to about 0.15 seconds, while the ratio of input speed to output speed is determined at more frequent intervals, such as about 0.01 second intervals, such that torque can be determined as a function of the clutch slippage. The speed ratio is checked frequently, for instance, 10 to 15 times during the ramp down of clutch pressure, resulting in 10 to 15 measured torque levels, to allow more precise adjustment of pressure in the off-going clutch, as well as the on-coming clutch.

Abstract: A method for controlling clutch pressures during power shifts involving detecting clutch slippage, utilizing individual pressure control. In the shift, the pressure in the off-going clutch is ramped down over a time interval, for instance, an interval of from about 0.10 seconds to about 0.15 seconds, while the ratio of input speed to output speed is determined at more frequent intervals, such as about 0.01 second intervals, such that torque can be determined as a function of the clutch slippage. The speed ratio is checked frequently, for instance, 10 to 15 times during the ramp down of clutch pressure, resulting in 10 to 15 measured torque levels, to allow more precise adjustment of pressure in the off-going clutch, as well as the on-coming clutch.

Abstract: A computer calibration method and apparatus for calibrating one or more auxiliary hydraulic valves on a work vehicle includes the steps of selecting a first auxiliary hydraulic valve, applying a valve opening signal to that valve, measuring a pressure in a flow restricted signal circuit coupled to the valve, comparing the first pressure with a predetermined pressure to see if the valve is cracked open and if the valve is not cracked open, incrementing the signal to a second level and repeating the foregoing steps until the first valve cracks open. The final step is saving a value indicative of the signal at which the valve just cracked open.

Abstract: A method of individually adjusting auxiliary hydraulic valves for work vehicles is provided such that they provide different maximum flow rates for opposite flow directions through the valve. The valve is controlled by a flow rate control for setting a maximum flow rate and is also controlled by a proportional control input device having one range of positions for providing a corresponding first range of flow rates in the one direction, a central position for providing substantially no flow, and another range of positions for providing a corresponding second range of flow rates in the other direction.

Abstract: A computer calibration method and apparatus for calibrating one or more auxiliary hydraulic valves on a work vehicle includes the steps of selecting a first auxiliary hydraulic valve, applying a valve opening signal to that valve, measuring a pressure in a flow restricted signal circuit coupled to the valve, comparing the first pressure with a predetermined pressure to see if the valve is cracked open and if the valve is not cracked open, incrementing the signal to a second level and repeating the foregoing steps until the first valve cracks open. The final step is saving a value indicative of the signal at which the valve just cracked open.