Abstract: A method and system for controlling an eddy current braking system in a motor vehicle is provided. The motor vehicle includes a prime mover linked to the eddy current braking system to provide torque thereto, and the eddy current braking system has a retarder assembly including at least a rotor and a stator. The method includes the steps of detecting a feedback current from the retarder assembly, detecting a rotor speed of the rotor, providing a signal indicative of a desired retarding torque, and determining a command current for the retarder as a function of the feedback current, rotor speed and desired retarding torque using a closed-loop sliding-mode control algorithm. The command current is provided to the retarder to control application of torque to the prime mover.

Abstract: A control system (12) for an automotive vehicle includes a wheel speed sensor (18) generating a rotational speed signal and a controller (14) coupled to the wheel speed sensor. The controller determines a vehicle speed, calculates wheel slip based upon the vehicle speed and the rotational speed, calculates a predicted future wheel slip based upon the vehicle speed and the rotational speed, estimates a normal force on the wheel, calculates a modified brake torque signal in response to the wheel slip, the predicted future wheel slip and the normal force, and actuates the wheel brake in response to the modified brake torque signal.

Abstract: A control system (12) for an automotive vehicle includes a wheel speed sensor (18) generating a rotational speed signal and a controller (14) coupled to the wheel speed sensor. The controller determines a vehicle speed, calculates wheel slip based upon the vehicle speed and the rotational speed, estimates a normal force on the wheel, calculates a modified brake torque signal in response to the wheel slip and the normal force, and actuates the wheel brake in response to the modified brake torque signal.

Abstract: An actuation system controls the flow of electric power to electromagnetic actuators to control motion or movement of at least two shafts or bodies. The system is preferentially applied to braking systems in automobiles and trucks, and may also be applied to other areas, including clutches and drive systems for other power transmission purposes. The electromagnetic retarders may also be used in combination with friction brake systems. Principal advantages of the combination system are the reliability and simplicity of friction and hydraulic components, and the lower wear and longer life of electromagnetic components.

Abstract: A method and system for controlling the steady-state speed of a cylinder in an electrohydraulic system having multiple cylinders includes a plurality of levers for controlling each of the cylinders. A controller, in communication with the levers and the hydraulic cylinders, has a limited number of parameters defining at least one desired relationship between steady-state speed and lever position for each of the cylinders stored therein. The controller further determines a current desired relationship for each of the cylinders from the associated at least one desired relationships. Upon detecting movement of the lever, the controller determines a current position of the lever associated with one of the cylinders and then controls the steady-state speed of the associated cylinder based on the limited number of parameters defining the current desired relationship and the position of the lever.

Abstract: An apparatus and method of controllably moving a moveable element within a hydraulic motor is disclosed. A lever device produces an operator command signal indicative of a desired velocity of the moveable element. An electronic controller receives the operator command signal, compares the operator command signal to a limit value, and produces a limited command signal in response to the operator command signal being greater than the limit value. An electrohydraulic controller receives the operator command signal and responsively controls the movement of the moveable element.

Abstract: A control system implements several methods for automating work functions of a machine. Single activation of an operator switch generates a command to automatically perform a desired work function. A controller determines whether conditions are satisfactory to perform the desired function. When the conditions are satisfactory, the work function is performed automatically without requiring the operator to manipulate levers that are otherwise used to control the work implement of the machine.

Abstract: A method and system for controlling the steady-state speed of a cylinder in an electrohydraulic system having multiple cylinders includes a plurality of levers for controlling each of the cylinders. A controller, in communication with the levers and the hydraulic cylinders, has a limited number of parameters defining at least one desired relationship between steady-state speed and lever position for each of the cylinders stored therein. The controller further determines a current desired relationship for each of the cylinders from the associated at least one desired relationships. Upon detecting movement of the lever, the controller determines a current position of the lever associated with one of the cylinders and then controls the steady-state speed of the associated cylinder based on the limited number of parameters defining the current desired relationship and the position of the lever.

Abstract: An electrohydraulic control device for a drive train of a machine having an engine, a transmission, and a torque converter utilizes sliding mode control and a target speed trajectory to constrain the jerk on the machine during a directional shift. Electrohydraulic valves produce fluid flow to hydraulic service brakes and an impeller clutch in the torque converter to controllably engage and disengage the transmission impeller clutch. A sensor generates a signal representative of the output speed of the transmission. An electronic controller receives the sensed speed signal, determines a desired speed signal according to the target speed trajectory, produces an error speed signal in response to a difference between the sensed and desired speeds, and controllably actuates the electrohydraulic valve to reduced any speed error, thereby changing the direction of motion of the machine under controlled jerk levels felt by the operator.