Caterpillar Inc.

Michael John Barngrover

Brian Dean Kuras

Thomas M Sopko

Brian Douglas Hoff

Brian Eugene Lister

Michael David Beyer

Frank A DeMarco

Michael G Cronin

Mark E Rettig

Hongliu Du

Adam Martin Nackers

William H Lane

Sangameshwar Sonth

Thomas Michael Sopko, Jr

Eric D Stemler

Kevin Anthony Davis

Steven R Krause

Baojun Si

Mustafa Guven

Mark A Robinson

Barry Mei

Corey Allen Kauk

Christopher Rhoades

Saurabh Pandey

Ben Evans

Keith Nicholas Edward Troisi

A work machine using a direct current power system that isolates reactive loads is described herein. The work machine uses a machine power distribution unit that receives direct current power from two or more battery banks of a power unit, whereby each of the battery banks deliver electrical power on a separate direct current bus. A machine power distribution unit of the work machine receives the electrical power from the battery and is used to isolate the power using bus connectors. One of the battery banks provides power to one direct current bus of the work machine and another battery bank provides power to another direct current bus of the work machine. A reactive load serviced by one of the battery banks is electrically disconnected from another reactive load serviced by the other battery bank.

Systems and methods for operating a divided power distribution system

A system and method for controlling a motor of an electric drivetrain having a multi-speed transmission with at least a first clutch and a second clutch. The system and method includes initiating a transmission shift requiring engagement of the first clutch, applying synchronizing torque commands to the motor based on an engagement parameter of the first clutch until the shift is complete, and applying non-shifting torque commands to the motor after the shift is complete.

System and method for controlling a motor during clutch shifting in a multi-speed electric drivetrain

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.

Control system for controlling operation of a machine by imposing shaped hysterisis

A system for hydraulically coupled multi-variator actuation is disclosed. One system includes: a first hydraulic variator comprising: a first hydraulic pump; and a first hydraulic motor linked to the first hydraulic pump. The system may further include a second hydraulic variator comprising: a second hydraulic pump; and a second hydraulic motor linked to the second hydraulic pump. The system may further include a first actuator linked to the first hydraulic pump and configured to control a displacement of the first hydraulic pump; a second actuator linked to the second hydraulic pump and configured to control a displacement of the second hydraulic pump; a hydraulic link connecting the first actuator and the second actuator, the hydraulic link configured to facilitate a coordinated operation of the first actuator and the second actuator; a valve disposed in fluid communication with the hydraulic link connecting the first actuator and the second actuator; and a controller connected to the valve and configured to control an operation of the valve to regulate hydraulic flow in the hydraulic link.

Hydraulically coupled multi-variator actuator

A system and method are provided for maintaining hydraulic steering for a machine during engine out or engine lugging conditions. The machine includes a torque-controlled transmission driven by an engine, the engine further being linked to a hydraulic steering pump that provides hydraulic power to a steering actuator. The machine may be, for example, a wheel loader or an off highway truck. The system and method include detecting an undesirable reduction of engine speed while the machine is travelling, and responsively reducing the transmission power to maintain the engine speed at a desired level to power the hydraulic steering pump. When the reduced requested transmission power reaches zero, a power reversal through the transmission is commanded to maintain the engine speed at the desired level to power the hydraulic steering pump.

Primary steering enabler during engine failure

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.

Torque and speed control in a machine with continuously variable transmission

System and method for controlling a transmission in response to transient torque events are disclosed. The method includes commanding a maximum transmission output torque; comparing the commanded output torque to a feedback torque to determine if they are equal; and incrementally increasing the transmission output torque until equal. A machine and a powertrain include a controller configured to command a maximum negative transmission output torque in response to a transient torque event, and incrementally increase the transmission output torque until such time as the transmission output torque is equal to or within a preset range of the feedback torque.

System and method for avoiding engine underspeed and stall

A transmission includes a transmission output speed (TOS) sensor providing a signal indicative of an output speed of the transmission. A controller estimates an actual torque output of the transmission and determines, in real time, a first TOS acceleration based on the signal provided by the transmission output speed sensor and a second TOS acceleration based on the actual torque estimation. The first and second accelerations are compared and a torque transient trigger is activated when the divergence exceeds a threshold value.

System and method for machine load detection

A machine is described that includes an electric drive for propelling the machine along a ground surface. The machine includes an electric power system having a first generator and a second generator. The electric power system also includes a first rectifier coupled to the first generator and having a first direct current (DC) power output and a second rectifier coupled to the second generator and having a second DC power output. Both the first DC output and the second DC output are coupled to the single DC bus, thereby providing an arrangement for the first rectifier and the second rectifier to simultaneously provide power to the single DC bus. A power balancer control receives power commands from both the first and the second ECMs and issues a corrective voltage adjustment to at least one of the first and second ECMs.

Power balancing for a dual generator single DC link configuration for electric drive propulsion system

A power train is provided having a power source for generating a power output. The power train also has a power storage device for storing and distributing power. The power train further has a controller configured to cause the distribution of power from the power storage device for assisting the power source when the rate of fuel entering the power source is above a threshold fuel rate. The threshold fuel rate is a fuel rate at which, assisting the power source increases the efficiency of the power train.

Hybrid engine system with transient load assistance

A method for dissipating power through a machine may include directing power into a power system of the machine. The method may further include controlling a parasitic load of the power system to increase dissipation of the power system, the controlling of the parasitic load being a function of a power dissipation limit of the power system.

Retarding control of a machine through power dissipation through power source and parasitic loads

A hydraulic motor system for improved frequency response includes a hydraulic variator having a pump and a motor, wherein the pump includes a variable angle swash plate, and the system further includes an electric actuator for controlling an angle or torque of the swash plate, thereby controlling the motor output characteristics. The electric actuator for controlling the variable angle swash plate may comprise a linear electric motor, ball screw drive or a rotary electric motor. In an example, the rotary electric motor tilts the swash plate by applying a torque to the swash plate at a point away from its tilt axis. In a further example, the rotary electric motor tilts the swash plate via a worm drive or ball screw drive.

Electric motor actuation of a hydrostatic pump

A system for controlling a machine with a continuously variable transmission includes a first control device configured to produce a first signal based on a first operator input and a second control device configured to produce a second signal based on a second operator input. The system also includes a control system configured to receive the first and second signals from the first and second control devices and generate a raw torque value based on the first and second signals. The control system is also configured to determine an output torque value based on the raw torque value and transmit the output torque value to the transmission to control the transmission.

System for controlling a machine with a continuously variable transmission

A method of adjusting the operation of an engine-driven machine to avoid engine under-speeding entails converting a received speed or torque command into a power command. When an engine under-speed condition is sensed, the system performs underspeed correction in the power domain before converting the underspeed processed power command back into the units of the original domain. The converted underspeed processed power command is issued to the transmission or other component to alleviate the engine under-speeding condition.

Power-based underspeed control

A system and method for optimizing machine performance using speed shaping in a machine having an engine and a drivetrain implementing engine underspeed module receives a throttle command requesting an increase in engine speed and transmits the throttle command to the engine. If the requested increase exceeds a predetermined function, the predetermined function is forwarded to the engine underspeed module as a speed standard. The engine underspeed module determines whether the actual engine speed attained by the engine is less than the speed standard by more than a predetermined gap value and, if so, reduces the power required by the drivetrain to avoid lugging of the engine.

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Peoria, IL, United States of America

Michael John Barngrover