Field of the invention
[0001] This invention relates to the field of a control unit to determine a main
throttle lever position in a vehicle.
Background of the invention
[0002] The movement of a throttle valve in a vehicle engine is responsive to the demand of the motor vehicle operator. Preferably, the air/fuel mixture is controlled in response to the throttle position. The speed regulation of a vehicle is conventionally accomplished through the depression of an accelerator pedal by the driver, which operates the throttle lever to vary the amount of mixture drawn into the engine. The power output or rotational speed of the engine and consequently the movement of the accelerator pedal representing the driver's will must be accurately reflected in the movement of the throttle lever. It is also necessary that in place of only one kind of linear relationship, the characteristic between the movement of the accelerator pedal and the movement of the throttle lever must be varied in many different ways in accordance with the output and operating conditions of the engine.
[0003] Prior art patent application US5681990 discloses a capacitive throttle position sensor comprising an electrode board having at least three electrodes, a driver for selectively driving the electrodes, and a rotary member including a dielectric that provides capacitive path to an output electrode. The output electrode is coupled to a signal processor that prepares the signal for comparison in a logical decoder with respect to an initiating driver electrode signal. Preferably, the phase difference between the output and input of the capacitive sensor provides an output signal which is not dependent upon the absolute capacitance of the element, and thus provides an output signal which can be adapted to a number of formats for motor vehicle control.

Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description
and illustrated in the accompanying drawing:
[0005] FIG. 1 illustrates a control unit in a vehicle in accordance to one embodiment of the invention; and
[0006] FIG.2 illustrates a flowchart of a method of determining a main throttle lever position in the vehicle.
Detailed description of the embodiments
[0007] FIG. 1 illustrates a control unit 12 to determine a position of a main throttle lever 14 in a vehicle 10 in accordance with one embodiment of the invention. The control unit 12 comprises a processing unit integrated. The control unit 12 comprises a sensing element 16 having a moving structure 18. The sensing element 16 connected to the main throttle lever 14 of the vehicle 10. The sensing element 16 adapted to sense a movement of the moving structure 18 based on a movement of the main throttle lever 14 of the vehicle. The control unit 12 adapted to determine the main throttle lever 14 position based on a signal from the sensing element 16.
[0008] Further the construction of the control unit 12 in the vehicle 10 and the working of the control unit 12 is explained as follows. The control unit comprises a processing unit (not shown), adapted to process the signal received from the sensing element 16. According to one embodiment of the invention, the sensing element 16 is a linear variable differential transducer. However, the sensing element 16 is not restricted to the mentioned sensing element type, but can be any sensing element 16 that is used to sense the

movement of the main throttle lever 14 position as known to a person skilled in the art. The vehicle 10 according to one embodiment of the invention is chosen from a group of vehicles comprising an off-high way vehicle, a construction vehicle or the like. The vehicle 10 comprises multiple acceleration pedals 20 operated by the user of the vehicle 10, while working, The multiple acceleration pedals 20 are connected to the main throttle lever 14 of the vehicle 10. The sensing element 16 is connected to the main throttle lever 14 as shown in the figure. The moving structure 18 present in the sensing element 16 is a shaft rod that is connected to a portion of the main throttle lever 14. The movement of the main throttle lever 14 moves the moving structure 18 of the sensing element 16. According to one embodiment of the invention, the control unit 12 is integrated in the sensing element 16. According to another embodiment of the invention, the control unit 12 is positioned outside of the sensing element 16 and the sensing element 16 transmits the detected position of the moving structure 18 to the control unit 12. The control unit 12 is chosen from a group of control units like a microprocessor, a microcontroller, an integrated digital chip or the like.
[0009] Fig 2 illustrating a flowchart for a method of determining a position of the main throttle lever 14 in a vehicle 10. In step S1, a movement of a moving structure 18 in a sensing element 16 is detected. In step S2, a signal from the sensing element 16 is transmitted to the control unit 12 based on the detected movement of the moving structure 18. In step S3, a stroke length of the sensing element 16 is calculated based on the received signal from the sensing element 16. In step S4, the main throttle lever 14 position is determined from the calculated stroke length of the sensing element 16.

[0010] The method of determining the main throttle lever 14 position in the vehicle is explained in detail. The main throttle lever 14 that is connected to the multiple acceleration pedals 20 of the vehicle, changes its position, when at least one acceleration pedal is operated. The main throttle lever 14 is connected to the moving structure 18 of the sensing element 16. The moving structure 18 moves in the linear direction due to the movement of the main throttle lever 14. The sensing element 16 senses the stroke length of the moving structure 18 and transmits the signal to the control unit 12. The control unit 12 receives the signal in the form of the voltage of the movement of the moving structure 18. The control unit 12 comprises a database having multiple voltage values mapped to multiple stroke lengths of the moving structure 18, which in turn mapped to multiple different angles of the main throttle lever 14. Upon receiving the signal from the sensing element 16, the control unit 12 determines the stroke length of the moving structure 18 and the position (deviated angle of the main throttle lever 14 position from a reference axis) of the main throttle lever 14.
[0011] With the above method and the control unit, the load on the engine is regulated in a more efficient way. Usage of the angular sensor is avoided making it a cost-effective solution. In the field run condition, the detection of the main throttle lever 14 position is possible with the above-disclosed method.
[0012] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

We Claim:
1. A control unit (12) to determine a position of a main throttle lever (14)
in a vehicle (10), said control unit (12) comprising a processing unit,
characterized in that:
- a sensing element (16) having a moving structure (18), said sensing element (16) connected to said main throttle lever (14) of said vehicle (10), said sensing element (16) adapted to sense a movement of said moving structure (18) based on a movement of said main throttle lever (14) of said vehicle;
said control unit (12) adapted to determine said main throttle
lever (14) position based on a signal from said sensing element
(16).
2. The control unit (12) as claimed in claim 1, wherein said sensing element (16) is adapted to transmit a voltage signal based on said movement of said moving structure (18), when said main throttle lever (14) of said vehicle (10) is operated.
3. The control unit (12) as claimed in claim 1, wherein said control unit (12) is adapted to calculate a stroke length of said sensing element (16), based on said received voltage signal from said sensing element (16).
4. The control unit (12) as claimed in claim 1, wherein said control unit (12) is adapted to determine said throttle position based on said determined stroke length of said sensing element (16).
5. The control unit (12) as claimed in claim 1, wherein said main throttle lever (14) of said vehicle (10) is connected to multiple acceleration pedals (20) of said vehicle (10).

6. The control unit (12) as claimed in claim 1, wherein said vehicle (10) is chosen from a group of vehicle comprising an off-highway vehicle, a construction vehicle or the like.
7. The control unit (12) as claimed in claim 1, wherein said sensing element (16) is a linear variable differential transducer.
8. A method of determining a positon of a main throttle lever (14) in a vehicle (10) by a control unit (12) , said method comprising :

- detecting a movement of a moving structure (18) in a sensing element (16);
- transmitting a signal to said control unit (12) based on said detected movement of said moving structure (18);
- calculating a stroke length of said sensing element (16) based on said received signal from said sensing element (16);
- determining said main throttle lever position from said calculated stroke length of said sensing element (16).