Claims:We Claim:
1. An electronic control unit (10) to detect a wear in a clutch (12) of a vehicle (11), said electronic control unit (10) adapted to :
- sense an engine speed and a vehicle speed from an engine speed sensor (14) and a vehicle velocity sensor (16);
- calculate a speed gradient and a vehicle acceleration from said sensed engine speed and said vehicle speed;
- map said calculated speed gradient with said vehicle acceleration;
- detect said wear in said clutch (12), when said calculated vehicle acceleration is less than at least one vehicle acceleration threshold value.

2. The electronic control unit (10) as claimed in claim 1, wherein said electronic unit (10) comprises a memory (18) adapted to store plurality of speed gradients mapped to plurality of vehicle accelerations and plurality of vehicle acceleration threshold values.

3. The electronic control unit (10) as claimed in claim 1, wherein said electronic control unit (10) adapted to generate an alert upon detecting said calculated vehicle acceleration less than said at least one vehicle acceleration threshold value.

4. The electronic control unit (10) as claimed in claim 3, wherein said generated alert is displayed on a dashboard (20) of said vehicle (11) using any one of the alerting means comprising an audio and a video.

5. The electronic control unit (10) as claimed in claim 3, wherein said electronic control unit (10) adapted to communicate said generated alert to a communication device (22) through at least one communication means (24).

6. The electronic control unit (10) as claimed in claim 4, wherein said communication means (24) is chosen from a group of communication means comprising a wired communication means, a wireless communication means.

7. The electronic control unit (10) as claimed in claim 1, wherein said electronic control unit (10) adapted to detect a degree of said wear of said clutch (12) based on a comparison between said calculated vehicle acceleration and said at least one vehicle acceleration threshold value.

8. A method of detecting a wear in a clutch (12) of a vehicle (11), said method comprising:
- sensing an engine speed and a vehicle speed from an engine speed sensor (14) and a vehicle velocity sensor (16);
- calculating a speed gradient and a vehicle acceleration from said sensed engine speed and said vehicle speed;
- mapping said calculated vehicle speed with said calculated vehicle acceleration;
- detecting said wear in said clutch (12), when said calculated vehicle acceleration is less than at least one vehicle acceleration threshold value.

9. The method as claimed in claim 8, generating an alert upon detecting said calculated vehicle acceleration is less than said at least one vehicle acceleration threshold value.

10. The method as claimed in claim 8, communicating said generated alert to a communication device (22) through at least one communication means.
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to an electronic control unit to detect a wear of a clutch in a vehicle and a method thereof.

Background of the invention
[0002] Clutches are well known devices, which are frequently employed in vehicles to selectively connect and disconnect a source of rotational power, such as the crankshaft of an engine, to a driven mechanism, such as a transmission. Typically, a cover of the clutch is connected to a flywheel carried on the end of the engine crankshaft for rotation therewith. Between the flywheel and the clutch cover, a pressure plate is disposed. The pressure plate is connected for rotation with the flywheel and the cover, but is permitted to move axially relative thereto. A release bearing is connected to the pressure plate such that axial movement of the release bearing causes corresponding axial movement of the pressure plate. When the clutch is new, the friction elements have a predetermined thickness. However, each time the clutch is engaged and disengaged the friction elements wear slightly thinner. After a certain amount of use, the thickness of the friction elements will have worn so thin that the clutch may not operate properly.

[0003] A Prior art document US6040768A discloses an arrangement for monitoring the wear status of a friction clutch in the drivetrain of a motor vehicle driven by an internal combustion engine. The arrangement includes a wear detection circuit that responds to speed information representing the instantaneous input speed of the friction clutch supplied by a first speed sensor and to information supplied by a movement sensor representing the beginning of a starting process. The wear detection circuit supplies, as a measurement for the loading of the friction clutch during a starting process, load information which is a predetermined monotonic function of a value of the first speed information following the beginning of movement after a predetermined time interval.
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 an electronic control unit in a vehicle in accordance with one embodiment of the invention; and
[0006] Fig. 2 illustrates a method of detecting a wear in a clutch of a vehicle in accordance with one embodiment of the invention.

Detailed description of the embodiments
[0007] Fig.1 illustrates an electronic control unit 10 to detect a wear in a clutch 12 of a vehicle 11, in accordance with an embodiment of the invention. The electronic control unit 10 adapted to sense an engine speed and a vehicle speed from an engine speed sensor 14 and a vehicle velocity sensor 16. The electronic control unit 10 adapted to calculate a speed gradient and a vehicle acceleration from the sensed engine speed and the vehicle speed. The electronic control unit 10 is adapted to map the calculated speed gradient with the vehicle acceleration. The electronic control unit 10 adapted to detect the wear in the clutch 12, when the calculated vehicle acceleration is less than at least one of vehicle acceleration threshold value.

[0008] Further, the construction of the electronic control unit 10 and the components of the electronic control unit 10 and their working are explained below. The electronic control unit 10 comprises a memory 18 having plurality of speed gradients mapped to plurality of vehicle accelerations and to plurality of vehicle acceleration threshold values. For example, the speed gradients that are calculated from the engine speed and the vehicle speed are S1, S2 and S3 and the vehicle acceleration values calculated are VA1, VA2, and VA3. The vehicle acceleration threshold values that are stored in the memory 18 are VAT1, VAT2, and VAT3. The memory 18 comprises a map or a database wherein the speed gradient values are mapped to the vehicle acceleration values and to vehicle acceleration threshold values. The below table illustrates the mapping of the above –disclosed parameters.
Speed gradients vehicle acceleration values Vehicle-acceleration threshold values
S1 VA1 VAT1
S2 VA2 VAT1
S3 VA3 VAT3

[0009] It is to be noted that, the number of speed gradient values and the number of vehicle acceleration values and the vehicle acceleration threshold values are not restricted to the above-disclosed number three, but can be “n” number of speed gradient values mapped to “n” number of vehicle acceleration values and “n” number of vehicle acceleration threshold values. When an accelerator pedal 25 position changes from 0% to 100%, then the electronic control unit 10 calculates the speed gradient, compares it with the corresponding vehicle acceleration, and if the speed gradient is higher and the vehicle acceleration is lower, then it is an indication that the clutch has started to wear out. Based on the vehicle acceleration threshold values set in the memory 18 a degree of wear can be determined.

[0010] The electronic control unit 10 adapted to generate an alert upon detecting the calculated vehicle acceleration less than the at least one vehicle acceleration threshold value. The generated alert is displayed on a dashboard 20 of the vehicle 11 using any one of the alerting means comprising an audio and a video, graphical representation. The alerting means can be a continuous blinking of light along with a sound on the dashboard 20 of the vehicle 11 upon detecting the wear of the clutch 12 of the vehicle 11. The electronic control unit 10 adapted to communicate the generated alert to a communication device 22 through at least one communication means 24. The communication device 22 is chosen from a group of communication devices like a smart phone, a mobile, a personal digital assistant, a navigation device and the like.

[0011] The communication device 22 that is used by a user of the vehicle will be able to get the information of the wear of the clutch 12 through the communication means 24. The communication means 24 is chosen from a group of communication means comprising a wired communication means, a wireless communication means. The wired communication means comprises a CAN bus and the like, wherein the wireless communication means comprises a Wi-Fi, a Bluetooth, an infrared and the like.

[0012] Fig. 2 illustrates a method of detecting a wear of a clutch 12 in a vehicle 11 according to one embodiment of the invention. In step S1, an engine speed and a vehicle speed from an engine speed sensor 14 and a vehicle velocity sensor 16 are sensed. In step S2, a speed gradient and a vehicle acceleration are calculated from the sensed engine speed and the vehicle speed by an electronic control unit 10. In step S3, the calculated vehicle speed is mapped with the calculated vehicle acceleration. In step S4, the wear in the clutch 12 is detected, when the calculated vehicle acceleration is less than at least one vehicle acceleration threshold value. In step S5, an alert is generated upon detecting the calculated vehicle acceleration is less than said at least one vehicle acceleration threshold value. In step S6, the generated alert is communicated to a communication device 22 through at least one communication means 24.

[0013] A detailed description of the method of working of the electronic control unit 10 is explained below. The electronic control unit 10 upon receiving the engine speed and the vehicle speed from the engine speed sensor 14 and the vehicle velocity sensor 16 calculates the speed gradient and the vehicle acceleration values. The electronic control unit 10 maps the calculated speed gradient with the calculated vehicle acceleration value. For a S1 speed gradient, the vehicle acceleration calculated should be VA1, when the clutch 12 is in a good condition. If the clutch 12 is worn out, then for the calculated speed gradient will be higher and the vehicle acceleration will be lower. The electronic control unit compares the calculated vehicle acceleration value VA1 with at least one of the vehicle acceleration threshold values. The VA1 is compared with VAT1, VAT2 and VAT3. The electronic control unit 10 is adapted to detect a degree of the wear of the clutch 12 based on a comparison between the calculated vehicle acceleration (VA1) and the at least one vehicle acceleration threshold value (VAT1/VAT2/VAT3).

[0014] For example, if the electronic control unit 10 detects the VA1 is less than VAT1, the electronic control unit 10 communicates the wear of the clutch 12 to the user of the vehicle 11 along with a generation of the alert in the dashboard 20 of the vehicle 11. If the electronic control unit 10 detects VA1 < VAT2, then along with the alert, a caution is generated to the user of the vehicle 11, to stop the vehicle 11. If the electronic control unit 10 detects VA1 < VAT3, the control unit 10 detects the failure of the clutch 12 and generates a high-level alert and the vehicle 11 is halted under safe conditions. Upon detecting the second level and third level of alerts (when VA1 is less than VAT2 and when VA1 is less than VAT3), the electronic control unit 10 provides additional information of nearby repair centers to the user of the vehicle 11. The alerts are communicated to the user of the vehicle 11 using the communication means 24.

[0015] With the above disclosed electronic control unit 10 and the method of detecting the wear of the clutch 12, the user is informed in advance to take the safety measures to stop the vehicle 11. No additional component is required to detect the wear of the clutch 12, thus making this a simple, cost-effective solution. The state of the clutch 12 is used as an additional checkpoint to ensure that the clutch 12 is fully engaged before the speed comparison.

[0016] 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.