Engine variable transmission control system
First Claim
1. An electronic control system for a self-propelled off-road vehicle having an internal combustion engine and a powershift transmission with a plurality of forward gears, said control system being for controlling powershift transmission and providing at least one control signal to said engine for specifying a speed at which said engine of said vehicle is to operate, said control system comprising:
- mode selection means for allowing an operator of said vehicle to select a desired one of a plurality of operating modes including a maximum fuel economy mode, a comfort mode and a maximum horsepower mode;
speed selection means for allowing said operator to select a desired vehicle ground speed;
first electronic controller means responsive to said mode selection means and said speed selection means and operable under stored program control for providing transmission control signals that specify in which specific one of said plurality of forward gears said powershift transmission is to operate in accordance with said selected operating mode; and
second electronic controller means operable under stored program control for providing at least one engine control signal required to command said engine to operate at one of a plurality of different engine speeds within a predetermined range in accordance with said desired vehicle ground speed,said first electronic controller means including first electrical output means for commanding said powershift transmission to operate in a controller selected one of said plurality of forward gears in response to said gear as specified by the current transmission control signals, and communications means for sending and receiving digital signals to and from said second electronic controller means,said second electronic controller means including second electrical output means for commanding said engine to operate at a particular one of said plurality of engine speeds indicated by said engine control signal, and communications means for sending and receiving digital signals to and from said first electronic controller means; and
when in said maximum fuel economy mode said electronic control system selects particular ones of said plurality of forward gears and particular ones of said engine speeds to minimize fuel consumption of said engine, said electronic control system further allowing said engine speed to vary slightly to help achieve minimum fuel consumption while attempting to maintain an operator selected vehicle ground speed;
when in said comfort mode said electronic control system selects particular ones of said plurality of forward gears and particular ones of said plurality of engine speeds to maintain an actual vehicle ground speed approximately equal to said operator selected vehicle ground speed while simultaneously reducing the number of shifts of said powershift transmission by varying said engine speed as necessary to compensate for changing loads experienced by said vehicle; and
when in said maximum horsepower mode said electronic control means selects various ones of said plurality of gears and varies said engine speed in an attempt to maintain said operator selected vehicle ground speed approximately equal to said actual vehicle ground speed while simultaneously maintaining said engine operating at one of said plurality of engine speeds that produces a maximum horsepower at said operator selected vehicle ground speed.
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Accused Products
Abstract
An electronic transmission control system for a self-propelled off-road vehicle having an internal combustion engine and multiple gear powershift transmission. The control system controls the powershift transmission and provides at least one control signal to the engine for selecting the speed at which the engine is to operate. The system includes a first electronic controller that provides transmission control signals required to command the powershift transmission to shift to and operate in any particular one of its forward gears, and second electronic controller that provides at least one engine control signal required to command the engine to operate at one of a number of different desired engine speeds and to monitor the actual engine speed. By use of gear ranges which overlap slightly, and a throttle that is infinitely adjustable within a range of engine speeds, any given ground speed within the range of possible vehicle speeds can be achieved and maintained, as long as engine is operating within its overall power envelope. Once the desired ground speed is specified by the operator, the control system automatically selects the specific transmission gear and engine speed required to achieve the desired ground speed. The control system also performs automatic upshifts or downshifts, as required, to achieve the desired ground speed. The system has a comfort mode, fuel economy mode, and a maximum horsepower mode, all selectable by the operator. The system also supports a pseudo-gear mode where the operator interface indicates there are more gears in the transmission than actually exist.
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Citations
23 Claims
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1. An electronic control system for a self-propelled off-road vehicle having an internal combustion engine and a powershift transmission with a plurality of forward gears, said control system being for controlling powershift transmission and providing at least one control signal to said engine for specifying a speed at which said engine of said vehicle is to operate, said control system comprising:
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mode selection means for allowing an operator of said vehicle to select a desired one of a plurality of operating modes including a maximum fuel economy mode, a comfort mode and a maximum horsepower mode; speed selection means for allowing said operator to select a desired vehicle ground speed; first electronic controller means responsive to said mode selection means and said speed selection means and operable under stored program control for providing transmission control signals that specify in which specific one of said plurality of forward gears said powershift transmission is to operate in accordance with said selected operating mode; and second electronic controller means operable under stored program control for providing at least one engine control signal required to command said engine to operate at one of a plurality of different engine speeds within a predetermined range in accordance with said desired vehicle ground speed, said first electronic controller means including first electrical output means for commanding said powershift transmission to operate in a controller selected one of said plurality of forward gears in response to said gear as specified by the current transmission control signals, and communications means for sending and receiving digital signals to and from said second electronic controller means, said second electronic controller means including second electrical output means for commanding said engine to operate at a particular one of said plurality of engine speeds indicated by said engine control signal, and communications means for sending and receiving digital signals to and from said first electronic controller means; and when in said maximum fuel economy mode said electronic control system selects particular ones of said plurality of forward gears and particular ones of said engine speeds to minimize fuel consumption of said engine, said electronic control system further allowing said engine speed to vary slightly to help achieve minimum fuel consumption while attempting to maintain an operator selected vehicle ground speed; when in said comfort mode said electronic control system selects particular ones of said plurality of forward gears and particular ones of said plurality of engine speeds to maintain an actual vehicle ground speed approximately equal to said operator selected vehicle ground speed while simultaneously reducing the number of shifts of said powershift transmission by varying said engine speed as necessary to compensate for changing loads experienced by said vehicle; and when in said maximum horsepower mode said electronic control means selects various ones of said plurality of gears and varies said engine speed in an attempt to maintain said operator selected vehicle ground speed approximately equal to said actual vehicle ground speed while simultaneously maintaining said engine operating at one of said plurality of engine speeds that produces a maximum horsepower at said operator selected vehicle ground speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An electronic control system for a self-propelled off-road vehicle having an internal combustion engine and multiple gear powershift transmission, said electronic control system being for controlling said powershift transmission and providing at least one control signal to said engine for selecting a speed at which said engine operates, said electronic control system comprising:
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means for receiving an operator selected desired vehicle ground speed, mode selection means for allowing an operator of said vehicle to select a desired one of a plurality of operating modes including a maximum fuel economy mode, a maximum horsepower mode and a comfort mode; electronic controller means for providing transmission control signals required to command said powershift transmission to operate in any given one of its said forward gears, and for providing at least one engine control signal required to command said engine to operate at any given speed within a range of possible engine speeds, said electronic controller means including first electrical output means for causing said powershift transmission to operate in a given transmission gear as indicated by said transmission control signals, second electrical output means for causing said engine to operate at a given engine speed as indicated by said engine control signal, and first automatic means, responsive to said means for receiving an operator selected desired vehicle speed, for selecting a transmission gear and then a desired engine speed required to achieve said desired vehicle speed; first means responsive to said mode selection means for causing said electronic control system to control shifting of said powershift transmission and to vary said engine speed of said vehicle as needed to obtain maximum fuel economy, while attempting to maintain an actual ground speed of said vehicle approximate equal to said desired vehicle ground speed, when said maximum fuel economy mode is selected; second means responsive to said mode selection means for causing said electronic control system to control shifting of said powershift transmission and to vary said engine speed of said vehicle as needed to cause maximum horsepower to be generated by said engine while simultaneously attempting to maintain said actual ground speed of said vehicle approximately equal to said desired vehicle ground speed; and third means responsive to said mode selection means for causing said electronic control system to control shifting of said powershift transmission and to vary said engine speed of said vehicle as needed to reduce the number of shifts of said powershift transmission in response to changing vehicle loads while simultaneously maintaining said desired vehicle ground speed approximately equal to an actual vehicle ground speed when operating in said comfort mode. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
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22. An electronic control system for a self-propelled off-road vehicle having an internal combustion engine and a powershift transmission having a plurality of forward gears, said control system controlling said powershift transmission and providing at least one control signal to said engine for selecting a speed at which said engine operates, said control system comprising:
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means for receiving an operator selected desired vehicle speed; means for enabling an operator to select one of a plurality of modes in which said engine may be operated, said modes including at least a fuel economy model a maximum power mode and a comfort mode; and electronic controller means for providing transmission control signals required to command said powershift transmission in any particular one of its said forward gears, and at least one engine control signal required to command said engine to operate at one speed within a range of possible engine speeds, and wherein said controller means, in response to said selection of a maximum power mode selects, for said desired vehicle speed, a transmission gear and an engine speed which produces substantially maximum output horsepower from said, and in response to a selection of said fuel economy mode selects, for said desired vehicle speed, a transmission gear and an engine speed corresponding to substantially optimal fuel economy from said engine for said desired vehicle ground speed, and in response to selection of said comfort mode causes said transmission gears to be selected and varies said engine speed as necessary to minimize the number of shifts required by said powershift transmission while simultaneously maintaining an actual ground speed of said vehicle approximately equal to said desired vehicle ground speed in spite of changing loads experienced by said vehicle; and said maximum power mode causing said electronic control system to control shifting of said powershift transmission and said engine speed of said engine to cause maximum horsepower to be generated by said engine at said desired vehicle ground speed. - View Dependent Claims (23)
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Specification