Abstract:
In one aspect of the present invention, an apparatus for controlling the negative load of an engine is disclosed. The engine is drivingly connected to a hydro-mechanical drive system that includes a variable displacement pump and motor. An engine speed sensor senses the rotational speed of the engine and produces an actual engine speed signal indicative of the rotational engine speed. A travel speed sensor senses the travel speed of the machine and produces an actual travel speed signal indicative of the machine travel speed. An overspeed controller compares the actual engine speed signal to a proportional and integral threshold, produces a proportional and integral error signal indicative of the difference between the actual engine speed signal magnitude and the corresponding thresholds, calculates a proportional and integral control signal from the corresponding errors, combines the proportional and integral control signals and responsively produces a command signal. A displacement controller receives the command signal and responsively controls one of the variable pump and motor to regulate the negative engine load to optimize the retarding power of the engine without overspeeding the engine or drivetrain.
Abstract:
A machine is described that includes an engine, a multi-clutch transmission and a controller. The controller is configured with computer-executable instructions for managing operation of the multi-clutch transmission to avoid autoengagement of a disengaged clutch. The computer-executable instructions configure the controller to receive sensor signals indicative of current operating status of the machine; determine, based upon the sensor signals, a configured minimum engine speed needed to avoid autoengagement of the disengaged clutch; and conditionally increase an engine speed based upon a comparison of the configured minimum engine speed and a sensed current engine speed. The machine includes a continuously variable transmission coupled to the multi-clutch transmission, and the controller is configured to adjust the continuously variable transmission ratio to counter the engine speed increase and thus maintain a current clutch output speed when increasing the engine speed to avoid autoengagement of a disengaged clutch.
Abstract:
A calibration system for calibrating a transmission provides a calibrated clutch fill time for an oncoming clutch by activating a parking brake of a machine associated with the transmission and calibrating each clutch by setting a transmission characteristic parameter to an initial value, and then activating a clutch solenoid associated with the clutch. The transmission characteristic is periodically measured, and when the measured value of the transmission characteristic exceeds the initial value for a predetermined number of consecutive periods, the fill time for the clutch is set equal to the time elapsed during the total number of measurement periods minus one less than the predetermined number of consecutive periods.
Abstract:
A variator torque control system adjusts a variator output so that the actual output torque of the variator closely matches an expected output torque. In an example, pressure values of an existing torque control map are supplemented in real time with calculated pressure supplement values based on the current operation of the variator. The pressure supplement value for each mapped pressure value may be derived based on a prior application of the same or another map value.
Abstract:
A variator torque control system and method utilize a hydraulic actuator to control the variator output via a torque control map, wherein the values of the torque control map are evaluated and modified during use of the map to improve map accuracy. In an example, errors in the map are evaluated to determine whether a system fault has occurred.
Abstract:
A predictive load management system is provided. A power source is operable to generate a power output and has a desired operating range. A transmission has a drive member operably engaged with the power source and a driven member. A control system is operable to receive at least one input indicative of a load on the transmission and to identify a desired load of the transmission based on the at least one input. The control system is also operable to receive at least one input indicative of current power output of the power source. The control system limits the desired transmission load applied to the driven member of the transmission based on the current power output of the power source to thereby prevent the power source from operating outside of the desired operating range.
Abstract:
A system for controlling intake pressure of a combustion engine operably coupled to a power generation system includes a sensor configured to output a signal indicative of a pressure in an intake system of the combustion engine and a sensor configured to output a signal indicative of a load on the power generation system. The system further includes a turbocharger operably coupled to the intake system. The system also includes an electric machine operably coupled to the turbocharger. The electric machine is configured to supply torque to the turbocharger. The system further includes a turbocharger controller operably coupled to the electric machine. The turbocharger controller is configured to control operation of the electric machine such that the turbocharger supplies a desired intake pressure to the combustion engine based at least partially on the signal indicative of a pressure in the intake system and the signal indicative of a load on the power generation system.
Abstract:
A transmission assembly having a hydrostatic transmission with a variable displacement hydraulic device which controls a motor speed ratio. The transmission assembly further includes a mechanical transmission coupled to the hydrostatic transmission and having a first range and a second range and an output shaft driven at a travel speed ratio. The torque through the hydrostatic transmission reverses when the mechanical transmission shifts from the first range to the second range. A synchronous travel speed ratio is the motor speed ratio which produces the same travel speed ratio in both the first gear range and the second gear range. An equal displacement travel speed ratio is the travel speed ratio at which a displacement of the variable displacement device in the second gear range is the same as the displacement in the first gear range. A travel speed ratio differential is a difference between the synchronous speed ratio and the equal displacement travel speed ratio. The shift from the first range to the second range is initiated at a travel speed ratio which varies from the equal displacement travel speed ratio by less than eighty percent of the travel speed ratio differential.
Abstract:
A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates an actual velocity signal in response measuring speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device, or speed pedal, which is positionable in one of an infinite number of positions and generates a desired velocity signal corresponding to the position of the speed pedal. The control apparatus yet further includes a controller operable to receive the desired velocity signal, receive the actual velocity signal, calculate a commanded acceleration ac, and generate a commanded velocity Vc based on the desired velocity signal, a jerk value j, and the commanded acceleration ac. A method of controlling a continuously variable transmission is also disclosed.
Abstract:
A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates actual velocity signals in response measuring a speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device which is positionable in one of a number of positions and generates a desired velocity signal corresponding to the one of the number of positions. The control apparatus yet further includes a controller operable to receive the desired velocity signals, receive the actual velocity signals, determine when rapid changes in the desired velocity are requested by an operator, and generate a commanded acceleration and a commanded velocity based on a jerk value which exceeds a predetermined jerk limit in response to the rapid changes in the desired velocity. A method of controlling a continuously variable transmission is also disclosed.