Control system for reverser transmission having aggressive and non-aggressive modes
First Claim
1. A vehicle control system comprising:
- a controller having a programmed acceleration circuit;
a forward acceleration pedal having a position sensor that is signal-connected to an input of said programmed acceleration circuit in the controller;
an electrically controlled hydraulic proportional control valve that is signal-connected to said programmed acceleration circuit of the controller;
a transmission responsive to said hydraulic proportional control valve to drive a wheel;
said programmed acceleration circuit includes a first programmed electric current control circuit having as a first output signal a first rate of change of electric current over time in response to said position sensor;
said programmed acceleration circuit includes a second electric current control circuit having as a second output signal a second rate of change of electric current over time in response to said position sensor;
a selection device for operator selection between said first and second electric current control circuits; and
said control valve proportionally responsive to a selected one of said first and second output signals.
1 Assignment
0 Petitions
Accused Products
Abstract
A control system for a utility vehicle transmission provides for operator selection of vehicle “aggressiveness,” or rates of acceleration in response to operator command. The aggressiveness of a vehicle'"'"'s performance can be controlled by modulating control signals to proportional control valves, which determine the transmission acceleration, according to two or more electrical ramp-up (or ramp-down) profiles, in response to an operator'"'"'s acceleration command (or deceleration command). The transmission control system includes a controller, directional switches and electro-hydraulic valves which control hydraulic pressure in the clutch packs in a reverser transmission. The operator is provided with a two-position set switch. With the set switch in the less aggressive position, in response to an operator'"'"'s command, the software in the controller provides a relatively slow current ramp to energize the control valves. With the switch in the more aggressive position, the current ramps and resultant pressure ramps are faster, thus causing more aggressive transmission operation for the reverser transmission.
24 Citations
20 Claims
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1. A vehicle control system comprising:
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a controller having a programmed acceleration circuit;
a forward acceleration pedal having a position sensor that is signal-connected to an input of said programmed acceleration circuit in the controller;
an electrically controlled hydraulic proportional control valve that is signal-connected to said programmed acceleration circuit of the controller;
a transmission responsive to said hydraulic proportional control valve to drive a wheel;
said programmed acceleration circuit includes a first programmed electric current control circuit having as a first output signal a first rate of change of electric current over time in response to said position sensor;
said programmed acceleration circuit includes a second electric current control circuit having as a second output signal a second rate of change of electric current over time in response to said position sensor;
a selection device for operator selection between said first and second electric current control circuits; and
said control valve proportionally responsive to a selected one of said first and second output signals. - View Dependent Claims (2, 3, 4, 5, 17, 18, 19, 20)
wherein said second rate of change of electric current causes hydraulic fluid pressure to said clutch pack to change at a second hydraulic pressure change rate when an acceleration signal is applied to said input of said programmed acceleration circuit;
said first hydraulic pressure change rate being greater than said second hydraulic pressure change rate.
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18. The control system according to claim 17, wherein said first and second hydraulic pressure change rates are substantially linear.
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19. The control system according to claim 18, wherein said first hydraulic pressure change rate is substantially twice the second hydraulic pressure change rate.
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20. The control system according to claim 1, wherein said first rate of change of electric current and said second rate of change of electric current are substantially linear sloped regions on a current versus time graph, and the linear region of said first rate of change of electric current is greater than the linear region of said second rate of change of electric current.
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6. A vehicle control system comprising:
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a controller having a programmed acceleration circuit;
a forward acceleration pedal having a position sensor that is signal-connected to an input of said programmed acceleration circuit in the controller;
a reverse acceleration pedal having a position sensor that is signal-connected to an input of said programmed acceleration circuit in the controller;
a forward electrically controlled hydraulic proportional control valve that is signal-connected to said programmed acceleration circuit of the controller;
a reverse electrically controlled hydraulic proportional control valve that is signal-connected to said programmed acceleration circuit of the controller;
a transmission responsive to said hydraulic proportional control valves to drive a wheel in forward or reverse respectively;
a first pressure sensor connected downstream of said forward control valve, and a second pressure sensor connected downstream of said reverse control valve, said first and second pressure sensors being signal-connected to said controller; and
said controller including a feedback circuit that controls said transmission based on signals from said first and second pressure sensors. - View Dependent Claims (7, 8)
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9. A vehicle control system comprising:
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a control;
a directional device activated by a user to send an acceleration demand signal to said control;
said control having an acceleration circuit receiving said acceleration demand signal and producing a selectable output signal proportional to said demand signal selectable between a first output signal and a second, greater output signal;
an operator controlled selector for selecting between said first and second output signals;
a transmission arranged for directing power to a wheel, said transmission responsive to said selectable output signal to accelerate said wheel. - View Dependent Claims (10, 11, 12, 13)
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14. A method of controlling the acceleration aggressiveness of a transmission, comprising the steps of:
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obtaining an acceleration input signal from an operator controllable device;
selecting one out of at least a first and a second acceleration function, each producing an output signal, said first acceleration function producing a first output signal and said second acceleration function producing a second, greater output signal;
said output signal being signal-connected to a transmission hydraulic control valve to control acceleration of said transmission. - View Dependent Claims (15, 16)
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Specification