Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Transmission control
Reexamination Certificate
2003-02-03
2004-08-31
Louis-Jacques, Jacques H. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Transmission control
C701S034000, C701S055000, C701S059000, C701S061000, C701S063000, C477S906000, C702S058000, C074S335000, C074S473100, C074S473120, C074S473240
Reexamination Certificate
active
06785599
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a method of detecting at least one predetermined shift position of a vehicle transmission among a plurality of different shift positions corresponding to different rotary transfer ratios between an input shaft and an output shaft. It further relates to a control device, to a vehicle transmission, as well as the use of the method, the use of the control device, and the use of the vehicle transmission. In addition, the invention also relates to a method of detecting a position change in relation to a reference position of a vehicle transmission.
A transmission in the present context means a device that can be shifted into different states, by an either stepwise or continuous variation, to generate different rotary transfer ratios between two shafts. The transmission is configured as a gear-changing transmission or a cone-pulley transmission, or other appropriate mechanism. The shift processes of the transmission can be controlled automatically or manually, or in a partially automatic mode, or in an automated mode that permits manual intervention by the driver. A transmission in the sense of the present invention can be configured so that shifts from one gear ratio to another cause an interruption in vehicle traction, or it can be configured to perform shifts without interrupting traction.
With preference, the transmission is configured as an automatic transmission which, in the context of the present invention, means a transmission that shifts without interrupting traction. With special preference, however, the transmission is configured as an automated shift transmission, a term which is used in particular for a transmission in which the control of the shift process is automated but causes an interruption in vehicle traction.
Transmissions as well as operating methods for transmissions belong to the known state of the art.
In a manual transmission, the gear shifts are performed manually by the driver. In principle, the driver is free to shift arbitrarily from any gear into any other gear. The driver chooses when to shift gears and which gear to shift into, based on certain criteria. The driver will decide to shift gears particularly in response to the sound of the engine and depending on which of the gears is currently engaged.
Errors in recognizing which gear is currently engaged, errors of shifting into an other than the intended gear, judgment errors about the need to shift gears, or other mistakes can cause damage to a transmission or can stall the engine of a vehicle. This kind of situation can occur, for example, in a vehicle coasting downhill with the transmission set to the neutral position, if the driver's foot is on the gas pedal so that the engine runs at a high rpm rate but the driver erroneously believes the transmission to be in first gear and therefore shifts into second gear.
Also known are automated shift transmissions in which the shifts are actuated by two electric motors. The electric motors apply a force to a shifter finger. The shifter finger moves in a pattern that consists of a selector track (also called neutral track) and shift tracks branching off from the selector track. The first of the electric motors moves the shifter finger in the direction of the shift tracks which terminate at the different gear positions, while the second of the electric motors moves the shifter finger in the direction of the selector track where the transmission is in the neutral state.
The shifter finger position is monitored by displacement sensors which are arranged at the electric motors and work according to an incremental detection principle.
The shifter finger is controlled by the electric motors dependent on the position values generated by the incremental sensors.
Automated shift transmissions of the foregoing description provide a satisfactory level of shifting and driving comfort and an economical way of operating a vehicle.
However, there have been incidents where gear shifts where performed incorrectly by transmissions of this type. Incorrect gear shifts are detrimental to the driving comfort in a vehicle with an automated shift transmission and will shorten the life of the transmission.
OBJECT OF THE INVENTION
The present invention therefore has the objective of providing a method of operating a vehicle transmission, as well as a transmission capable of performing the method, with an at least reduced incidence of incorrect gear shifts, a longer operating life, and an improved level of comfort for the driver and passengers of a vehicle that is equipped with the inventive transmission. In particular, the invention has the objective of providing a method of operating a transmission, as well as a transmission capable of performing the method, wherein the current shift position or shift movements from one position to another can be detected and evaluated more accurately and reliably and wherein detection errors can be corrected, so that detected positions or shift movements reflect the actual positions or movements of the transmission.
SUMMARY OF THE INVENTION
To meet the objective stated above, the invention proposes a method of detecting at least one predetermined gear-shift position of a transmission that has a plurality of different operating states corresponding to different rotary transfer ratios between an input shaft and an output shaft of a vehicle transmission. A transmission that is operable by the inventive method has a shift pattern with a selector track and shift tracks. A first shifter element, in particular a shifter finger, is movable within the shift pattern. The transmission also includes a second shifter element, in particular a shifter shaft or a shift rod. The transmission is further equipped with an actuator device running under the control of an electrical control device to actuate at least one of the first and second shifter elements. At least one position-sensor device is provided in the transmission to determine the position of a movable element of the transmission.
The method according to the invention has the following steps:
a) When a set of predetermined conditions are present, an actuating force is applied by the actuator device to at least one of the shifter elements in accordance with a predetermined characteristic.
b) At least one characteristic electrical variable of the actuator device and/or the control device, particularly an electric current, is monitored as a function of time.
c) The profile of the electrical variable as a function of time is evaluated according to a predetermined evaluation characteristic to determine a shift position that the transmission is set at. This determination is based on a functional dependency between the time profile of the characteristic electrical variable and the shift position.
The shift positions to be determined by the inventive method include in particular at least one end position of a shift-track and/or at least one specific position in the selector track and/or any position in the selector track.
The second shifter element, which consists of a shifter shaft, a shift rod, a shift fork, or a similar element, is connected to the first shifter element.
The arrangement of a selector track and shift tracks, as well as the first and second shifter elements, are part of a gear-shifting mechanism.
At least one movable element of the gear-shifting mechanism, such as the first or second shifter element, can be subjected to actuating forces under the control of an actuator device, causing the element to move, at least to the extent that the movement is not prevented by other factors or elements of the mechanism, such as end stops.
An actuator device in the sense of the present invention is a device that can convert one form of energy into another, generating an output that actuates the shift mechanism or at least one of the movable elements of the shift mechanism. In particular, the actuator device has at least one electric motor that converts electrical energy into mechanical motion. With preference, the actuator device has two electric mot
Berger Reinhard
Hauptmann Marc
Henneberger Klaus
Küpper Klaus
Vornehm Martin
Darby & Darby
Louis-Jacques Jacques H.
LUK Lamellen und Kupplungsbau Beteiligungs KG
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