Abstract:
A method regulates the torque output and/or speed output of a continuously variable transmission (CVT) in a manner that may simulate a clutch. The CVT may be incorporated in a machine and maybe operatively coupled to a power source and to a propulsion device. The method utilizes an unaltered torque-to-speed curve that relates the torque output to the speed output of the CVT. The method may receive an operator input signal indicating a desire to change operation of the machine. The torque-to-speed curve may be shifted in response to the operator input signal to limit the torque output available. In an aspect, an under-run curve may be applied to the torque-to-speed curve, the under-run curve corresponding to a target speed. The operator input signal may also shift the under-run curve to reduce the target speed.
Abstract:
A work machine with a mechanical brake touch-up system includes a power source that provides power to a rotational element. The work machine includes a brake that is configured with a piston to selectively engage a frictional element rotationally coupled to the rotational element, a position sensor for generating a position signal of the piston, and a control valve configured to supply hydraulic pressure to the piston to selectively apply a retarding torque to the frictional element, a speed sensor for generating a rotational speed signal. The work machine includes a touch-up controller which is configured to detect a retarding condition of the work machine based on the speed signal, and, upon detection of a retarding condition, control the position of the piston to a touch-up position between an engaged and retracted position.
Abstract:
A system and method are provided for controlling a movable element in accordance with a speed command. The movable element, which may be an excavator swing platform, is moved via an actuator that is driven in accordance with a torque command. The speed of the movable element is sensed, and a torque command is generated via PID control based on the speed command and the sensed speed. The PID control uses a set of gains including a P-gain, an I-gain, and a D-gain. At least one of these gains is set based on a counter, and the counter is set, cleared, incremented, or decremented based on one or more of the speed command, the torque command and the sensed speed. In this way, the movable element responds aggressively to operator input, but stability is maintained.
Abstract:
A control system for controlling operation of a drive motor includes an input device for providing a command signal that is indicative of a desired speed and direction of rotation of the drive motor. A sensor is associated with the drive motor and adapted to provide a sensor signal indicative of current rotational speed of the drive motor. A controller receives the command signal, and determine whether the command signal is indicative of a desired zero speed to be associated with the drive motor. The controller also receives the sensor signal, and determine whether the current rotational speed of the drive motor is within a pre-defined range of difference from the desired zero speed. The controller then generates a de-rated torque command signal having a reduced gain factor, and reduce the current rotational speed of the drive motor based on the de-rated torque command signal.
Abstract:
A braking system is disclosed. The braking system may include a controller configured to determine a power limit for one or more brakes of a machine based on a temperature of the one or more brakes during engagement of the one or more brakes according to a commanded power. The power limit may be a power at which the temperature of the one or more brakes ceases to increase. The controller may be configured to determine a speed adjustment for the machine based on the power limit and the commanded power, and cause adjustment to a speed of the machine based on the determined speed adjustment.
Abstract:
A control system for a machine having at least one control element is disclosed. The control system includes multiple input sensors in communication with the control element. The input sensor generates an input signal based on an input to the control element. The control system includes multiple actuating members to control operations of the machine. The control system includes a controller in communication with the input sensors and the actuating members. The controller receives the input signal from the input sensor and determines an imposed hysteresis level corresponding to the input signal based on a hysteresis input function. The controller is further configured to generate a hysteresis conditioned input signal based on the imposed hysteresis level.
Abstract:
A system and method are provided for controlling a movable element in accordance with a speed command. The movable element, which may be an excavator swing platform, is moved via an actuator that is driven in accordance with a torque command. The speed of the movable element is sensed, and a torque command is generated via PID control based on the speed command and the sensed speed. The PID control uses a set of gains including a P-gain, an I-gain, and a D-gain. At least one of these gains is set based on a counter, and the counter is set, cleared, incremented, or decremented based on one or more of the speed command, the torque command and the sensed speed. In this way, the movable element responds aggressively to operator input, but stability is maintained.
Abstract:
A control system for a machine having at least one control element is disclosed. The control system includes multiple input sensors in communication with the control element. The input sensor generates an input signal based on an input to the control element. The control system includes multiple actuating members to control operations of the machine. The control system includes a controller in communication with the input sensors and the actuating members. The controller receives the input signal from the input sensor and determines an imposed hysteresis level corresponding to the input signal based on a hysteresis input function. The controller is further configured to generate a hysteresis conditioned input signal based on the imposed hysteresis level.