Caterpillar Inc.

Jerry D Marr

Alan R Coutant

Michael G Cronin

Sanjay Rajagopalan

Brian Dean Kuras

Anthony C Rodman

Kevin Jay Lueschow

Noel J Rytter

Howard A Marsden

William Christopher Swick

Kenneth P Liesener

Benjamin Treichel

Friedrich Konrad Diecke

A method and apparatus are disclosed for controlling a hybrid energy system including a method of storing energy within a hybrid energy system. The hybrid energy system includes a traction load and a first energy consuming system configured to maintain a first criteria within a first operating range. The method includes receiving energy into the hybrid energy system from the traction load and distributing a first energy to the first energy consuming system when the first criteria is within the first operating range.

System for controlling a hybrid energy system

A machine, including a hydraulic pump and one or more hydraulic implements connected to the hydraulic pump. The machine may also include a hydraulic motor connected to the hydraulic pump and one or more propulsion devices. Additionally, the machine may include drive-system controls operable to selectively cause the hydraulic motor to supply power to one or more of the propulsion devices.

Drive system for a machine

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 a,, and generate a commanded velocity V,based on the desired velocity signal, a jerk value j, and the commanded acceleration a,. A method of controlling a continuously variable transmission is also disclosed.

Method and apparatus for generating velocity commands for a continuously variable transmission

A system and process for providing different levels of jerk in response to speed pedal displacement in a machine including a speed pedal having a range of displacement, a continuously variable transmission, a mechanism for measuring output speed of the continuously variable transmission, and an electronic controller for generating a jerk command signal that is in a one-to-one correspondence with the displacement of the speed pedal and shaping the jerk command signal into a velocity profile command that is applied to the continuously variable transmission and then comparing the output speed of the continuously variable transmission with the velocity profile command for controlling the continuously variable transmission.

System and method for providing different values of jerk in response to

A default mode control system for controlling a split torque transmission is disclosed. The default mode control system monitors various inputs to the control to detect an on board electrical, electronic fault or mechanical, hydraulic fault. When a fault is detected, the default mode control will recover from the default and then will limit operation of the split torque transmission based on the fault input.

Default mode control system for a split torque transmission

The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Method and system for controlling a split torque transmission

A method is disclosed for controlling the shift points in a continuously variable transmission having a closed loop control wherein the output of the continuously variable transmission is generated by a hydrostatic transmission or by a combination of the hydrostatic transmission and a mechanical transmission having a summing planetary and high and low speed clutches. The method comprises the steps of sensing the input and output speeds of the continuously variable transmission and the speed of the output from the hydrostatic transmission to monitor the speed ratios therein, comparing an operative transmission speed ratio of the transmissions to a predefined established transmission speed ratio, disengaging the high or low speed clutch once the predefined established transmission speed ratio is reached, increasing or decreasing the speed of the output of the hydrostatic transmission following disengagement of the high or low speed clutch, and engaging the other of the high or low speed clutch once the change in output speed of the hydrostatic transmission has substantially synchronized the speeds relative to the high or low speed clutches so that the output torque and speed of the transmission before and after the shift is substantially equal.

Method for controlling shift points in a continuously variable

An integrated power transmitting system includes a hydrostatic transmission and a mechanical transmission both being driven by an engine. The output of the hydrostatic transmission and the mechanical transmission are both selectively coupled to a work system through a final output shaft. A sensing arrangement senses the transmission input speed, the output of the hydrostatic transmission and the speed of the final output shaft and delivers the signals to the microprocessor. The microprocessor processes the received signals on a continuous basis and delivers a first set of command signals to control operation of the hydrostatic transmission and a second set of control signals to selectively control forward and reverse direction and high and low clutches within the mechanical transmission. A planetary arrangement within the mechanical transmission sums the speed of the hydrostatic transmission with a full range forward and reverse gear mechanism. This arrangement provides a smooth and continuous change in the speed of a machine in both the forward and reverse directions throughout its entire speed range.

Integrated power transmitting system

In many hydrostatic systems, the variable displacement pump is controlled by an operator moving a directional control valve to provide pressurized fluid to the displacement changing mechanism thereof which in turn varies the displacement responsive to the degree of pressurized fluid being directed to the displacement changing mechanism. In order to insure that the displacement of the Variable displacement pump is at the desired displacement, various forms of follow-up mechanisms have been required. These follow-up mechanisms are many times complicated and expensive to add to the hydrostatic system. In the subject arrangement, the speed of the pump input shaft and the speed of the motor output shaft is sensed (R,S) and the signals directed to a microprocessor which in turn processes the signals and directs a control signal (P) to a solenoid operated proportional valve. The solenoid operated proportional valve moves in response to the control signal and directs pressurized fluid to the displacement controller of the variable displacement pump to change the displacement thereof. Once the speed of the output shaft is achieved, the microprocessor modifies the control signal to maintain the variable displacement pump at the needed displacement position to maintain the desired speed of the output shaft to a work system. This arrangement provides an accurate control of the displacement of the variable displacement pump without the need of providing complicated follow-up mechanisms and/or servo mechanisms.

Control arrangement for a hydrostatic system

Vehicles having front and rear pairs of steerable wheels are sometimes provided with large springs for moving one pair of the wheels to a straight-ahead position during emergency steering. Large amounts of hydraulic energy are expended solely for the compression of such springs every time the pair of wheels are steered. A back-up steering control system (19) of the present steering control arrangement (10) has a servo valve (76) operative to control the flow of pressurized fluid from a back-up pump (60) to a steering control valve (21) which in turn controls the flow of pressurized fluid from the back-up pump to a hydraulic actuator (13) to hydraulically move a first pair of steerable wheels (11) to a straight-ahead position during emergency steering conditions. A manual control valve (68) is operative to control the flow of pressurized fluid from the back-up pump (60) to another steering control valve (22) which in turn controls the flow of pressurized fluid to a hydraulic actuator (16) for effecting steering of a second pair of steerable wheels (12) during the emergency steering condition.

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Metamora, IL, United States of America

Jerry D Marr