Claims:We claim: -
1. An Electronic Control Module (ECM) (110) to operate a clutch (116) in a semi-automatic transmission vehicle, said ECM (110) is adapted to:
receive at least one input signal (108) related to position of a gear lever (104),
process said at least one input signal (108) and generate an offset signal (306) to detect a shift intention,
compare value of said at least one input signal (108) with at least one value selected from a group comprising a threshold value (308) for detection of shift intention from a current gear which is retrieved from a memory element (112) and a generated value of said offset signal (306), and
determine a type of said shift intention as any one selected from a group comprising a fast shift and a normal shift based on said comparison, and operate said clutch (116) accordingly.

2. The ECM (110) as claimed in claim 1, is further adapted to generate said offset signal (306) in dependence of a delay signal (304), said delay signal (304) is obtained from said at least one input signal (108) after a specific computation process.

3. The ECM (110) as claimed in claim 1, is further adapted to validate a shift intention detected from movement of said gear lever (104) based on a pattern of movement of said gear lever (104), said pattern of movement comprises moving said gear lever (104) to an extreme end position of said current gear and then moving towards a desired gear.

4. The ECM (110) as claimed in claim 1, is further adapted to reject detection of unintentional shift due to oscillation of said gear lever (104) at said current gear.

5. The ECM (110) as claimed in claim 1, comprises an individual threshold value (308) for detection of shift intention for at least one gear of a gear layout (102).

6. The ECM (110) as claimed in claim 1, dynamically adapts said threshold value (308) for detection of a shift intention for each gear during subsequent usage of said gear lever (104).

7. A method for operating a clutch (116) in a semi-automatic transmission, said method comprises the steps of:
receiving at least one input signal (108) related to position of a gear lever (104);
processing said at least on input signal (108) and generating an offset signal (306) for detecting said shift intention;
comparing value of said at least one input signal (108) with at least one value selected from a group comprising a threshold value (308) for detecting a shift intention of a current gear which is retrieved from a memory element (112) and a generated value of said offset signal (306), and
determining based on said comparison a type of said shift intention as any one selected from a group comprising a fast shift and a normal shift, and operating said clutch (116) accordingly.

8. The method as claimed in claim 7, further comprises generating said offset signal (306) in dependence of a delay signal (304) obtained by processing said at least one input signal (108).

9. The method as claimed in claim 7, further comprises validating said shift intention based on a pattern of moving said gear lever (104), wherein said pattern of moving comprises moving said gear lever (104) to an extreme end position of said current gear and then bringing towards a desired gear.

10. The method as claimed in claim 7, further comprises providing independent threshold value (308) for detecting a shift intention for each gear of a gear layout (102), and further dynamically adapting said threshold values (308) during subsequent usage of said gear lever (104). , Description:Field of the invention:
[0001] The present disclosure relates to a controller or processor to control a clutch for a vehicle with semi-automatic transmission, and particularly relates to a method for operating the clutch in the semi-automatic transmission.
Background of the invention:
[0002] According to a patent literature US5377797, a clutch engagement control method in response to transmission shift lever position is provided. The method to control a driveline clutch system disposed between an engine and a manual or semi-automatic transmission where position sensors indicate the location of a gearshift lever in a gear selection gate to provide information to a clutch controller connected to a clutch actuator. The clutch is engaged when the gearshift lever is moved past the 80 percent position to a 100 percent position in a gear selection gate and the clutch is disengaged when the gearshift lever is moved from the 100 percent position to the 20 percent position in a gear selection gate.
[0003] In the electronic clutch systems the clutch is actuated by a clutch actuator. The response of the clutch actuator is comparatively slow as far as compared to a driver’s request. Due to irregularities in manufacturing and different resting positions of gear lever, detecting shift intension to open the clutch has a different impact on each gear for the same gear lever movement such as triggering unintentional clutch open request for few gear, no triggering of clutch open request for few gear, and the like.
[0004] Further, response of the clutch actuator is very slow and it is not possible to have a very high response actuator because of mechanical and electronic constraints. So to open the clutch when intended by the driver in a semi-automatic transmission, the clutch actuator can open the clutch usually in 150 to 200 milliseconds as the fastest. But it is seen that while doing a very fast shift, the driver shifts the gear lever (from gear to neutral) in less than 100 milliseconds. Sometimes, the clutch gets opened if the driver is holding the gear lever while driving and a slight movement is detected.
[0005] Therefore, the clutch needs to open when a slight movement in the gear lever is detected in order to avoid the reverse force/ notch acting on the driver. Further, a valid shift intention of the driver needs to be detected to avoid unintentional opening condition for the clutch.
Brief description of the accompanying drawings:
[0006] An embodiment of the disclosure is described with reference to the following accompanying drawings,
[0007] Fig. 1 illustrates an Electronic Control Module (ECM) to operate a clutch in a semi-automatic transmission, according to an embodiment of the present disclosure;
[0008] Fig. 2 illustrates normalization of gear lever positions, according to an embodiment of the present disclosure;
[0009] Fig. 3 illustrates a graphical representation for detecting a type of gear shift intention, according to an embodiment of the present disclosure;
[00010] Fig. 4 illustrates a pattern of gear lever movement to detect a valid shift intention of a driver, according to an embodiment of the present disclosure;
[00011] Fig. 5 illustrates a gear position layout where each gear is provided with individual threshold value for detection of shift intention, according to an embodiment of the present disclosure;
[00012] Fig. 6 illustrates rejection of unintentional shift due to gear lever oscillations, according to an embodiment of the present disclosure.
[00013] Fig. 7 illustrates a method for operating an operating a clutch in a semi-automatic transmission, according to an embodiment of the present disclosure.
Detailed description of the embodiments:
[00014] Fig. 1 illustrates an Electronic Control Module (ECM) to operate a clutch in a semi-automatic transmission, according to an embodiment of the present disclosure. The ECM 110 is adapted to receive at least one input signal 108 related to position of a gear lever 104. The position of the gear lever 104 is either at rest when a driver does not intend to change the gear, or in motion when the driver is changing to another gear. Further, the position of the gear lever 104 comprises position coordinates as obtained from at least one sensor 106 installed to monitor/track the position of the gear lever 104. Once, the position of the gear lever 104 is acquired, the ECM 110 processes the at least one input signal 108 and generates an offset signal 306 as shown in Fig. 3. The offset signal 306 is used to detect a shift intention of the driver. The ECM 110 further compares value of the at least one input signal 108 with at least one value selected from a group comprising a threshold value 308 and a generated value of the offset signal 306. The threshold value/ signal 308 as shown in Fig. 3 is retrieved from a memory element 112 for detection of shift intention from a current gear to a desired gear. The offset signal 306 is generated in real time by the ECM 110. The comparison is based on the at least one input signal 108 received due to the movement of the gear lever 104. The ECM 110 determines based on the comparison, a type the shift intention as any one selected from a group comprising a fast shift and a normal shift. The ECM 110 then operates the clutch 116 accordingly by sending control signals to a clutch actuator 114. The clutch actuator 114 is any one selected from a group comprising mechanical, hydraulic, pneumatic, electronic, and the like. Further, the semi-automatic transmission also corresponds to the automated manual transmission or to a transmission with automated clutch.
[00015] In accordance to an embodiment of the present disclosure, the ECM 110 is only adapted to control the clutch 116 on detection of a fast shift or a normal shift, and is independent of the Engine Control Unit (ECU) (not shown) of a vehicle. The ECM 110 works in response and in communication with the ECU. Alternatively, the ECM 110 is a single controller to control and operate as the ECU of the vehicle. The ECM 110 then receives input signals such as speed, torque, fuel, air-to-fuel ratio and the like to control the complete operation of the vehicle.
[00016] Fig. 2 illustrates normalization of gear lever positions, according to an embodiment of the present disclosure. An H-type gear layout 102 also known as five-speed shift pattern layout is considered for explanation, and hence is equally applicable for other types of gear layouts 102. The other types of gear layouts 102 comprises but not limited to a two-speed gear shift layout, a three-speed gear shift layout, a four-speed gear shift layout, a six-speed gear shift layout and the like. The numeral 202 corresponds to any one odd numbered gear such as 1st gear, 3rd gear, 5th gear and the like. Similarly, the numeral 204 corresponds to even numbered gear such as 2nd gear, 4th gear and 6th gear. The 6th gear corresponds to the reverse gear. A Neutral gear 210 with respective band is shown in Fig. 2.
[00017] With reference to line 206, the position of the gear lever 104 is normalized, i.e. the stationary/resting points of the gear lever 104 at each gear location is normalized to get 20% for gears above the band of the Neutral gear 210 and 80% for the gears below the band of the Neutral gear 210. For example, odd numbered gears 202 i.e. 1st gear, 3rd gear and 5th gear are above the Neutral gear 210 and the even numbered gears 204 i.e. 2nd gear, 4th gear and 6th gear are below the Neutral gear 210. So as per the normalized gear positions, the odd numbered gears 202 are at 20% of the length from respective gear end position to the Neutral gear 210 which is at 50%. Similarly, the even numbered gears 204 are at 80% from the Neutral gear 210 which is at 50%.
[00018] For every gear, an initial position value of the gear lever 104 from at least one sensor 106 is stored in the memory element 112. The storage of initial gear position values is usually carried out but not restricted to at an End of Line (EOL) procedure of the vehicle at the Original Equipment Manufacturer (OEM) premise, in the production factory, and the like. In EOL the gear lever 104 is moved to each gear location and the ECM 110 records/ stores the at least one positional values. The stored at least one positional values of the gear lever 104 at each gear location is considered a base for normalization of the positional signals during usage by the driver.
[00019] Now with reference to line 208, once the vehicle is out of the factory and when the driver uses and moves the gear lever 104 to a particular/desired gear location, then the normalized positional values of gear lever 104 is used for shift intention and corresponding actions of the clutch 116. For example in the H-type gear layout 102, the 1st gear, 3rd gear and 5th gear from the odd numbered gears 202 and the 2nd gear, the 4th gear and the 6th gear from the even numbered gears 204 are in a first lane, second lane and a third lane respectively. During EOL the value of at least one sensor 106 for the 1st gear is recorded as 1.2V. Now, after regular usage when the gear lever 104 is moved back to 1st gear by the driver, the voltage value received is 1.4V. During EOL the ECM 110 automatically records 1.2V as normalized to 20% hence 1.4V is normalized to (for example) 24%. But now, the new signal of the gear lever 104 recorded as 1.4V is learnt and adapted as 20%. Thus the line 208 indicates that though the values of the at least one sensor 106 is changing, the resting positon of the gear lever 104 is adapted to the changed values as per the usage by the driver.
[00020] The ECM 110 itself performs normalization. Alternatively, a normalization module independent from the ECM 110 or within the ECM 110 is provided.
[00021] Fig. 3 illustrates a graphical representation for detecting a type of gear shift intention, according to an embodiment of the present disclosure. The X-axis 310 represents time in a suitable measuring unit. The Y-axis 312 represents position of the gear lever 104 in percentage. The position of the gear lever 104 is normalized, i.e. the stationary/resting points of the gear lever 104 at each gear location is normalized to get 20% for gears above the neutral gear 210 and 80% for the gears below the neutral gear 210, and 50% for Neutral gear 210 as explained in Fig. 2. The normalization assists in processing the position of gear lever 104 irrespective of irregularities and also avoiding vehicle to vehicle differences.
[00022] The curve for a gear lever signal 302 is shown. The gear lever signal 302 is either the same as at least one input signal 108, or derived from the at least one input signal 108 after filtering and processing. The gear lever signal 302 is shown to be moved from neutral gear 210 to an odd numbered gear 202 and then back to neutral gear 210. The curve for the delay signal 304 (such as time delay) is generated by the ECM 110. The delay signal 304 is dependent on and always follows the gear lever signal 302. The delay signal 304 is generated by the ECM 110 as configured, and also allows to be configured. For example, the delay signal 304 follows very closely with the gear lever signal 302 till 20%, and later the difference between the two curves 302 and 304 increases, followed by again the differences being reduced as the gear lever signal 302 reaches to neutral 50%. After some time, the gear lever signal 302 and the delay signal 304 meet or intersect each other. Alternatively, at one instant of time, the delay signal 304 and the gear lever signal 302 have a same or common value.
[00023] The curve for the offset signal 306 is generated by the ECM 110. The offset signal 306 is depended on the delay signal 304. The offset signal 306 corresponds to a signal which is always less or more by a predetermined value from the delay signal 304. Hence, the delay signal 304 and the offset signal 306 never meet or intersect each other. Alternatively, the values of the delay signal 304 and the offset signal 306 are never equal.
[00024] A straight line though corresponds to 25% of the movement of the gear lever 104, but signifies a threshold value 308 of the current engaged gear. The threshold value 308 indicates detection of the shift intention when the gear lever 104 is moved from the current gear to a desired gear.
[00025] In accordance to an embodiment of the present disclosure, the ECM 110 is configured to determine a nature/ type of gear shift requested by the driver. The type of the shift intention is selected from a group comprising a fast shift and a normal shift. During fast shifts the movement of gear lever 104 is faster when compared to slow/ normal shifts, so gear disengagement or clutch open condition is enabled whenever the gear lever signal 302 reaches the offset signal 306 when the gear lever 104 is moved from the current gear to the desired gear. The offset signal 306 is generated in such a manner that its value is always closer to the 20% position of the gear lever 104 than the signal for the threshold value 308. Hence, the ECM 110 detects the values of the offset signal 306 and the gear lever signal 302 to be equal much earlier than the threshold value 308 of the current gear, and triggers clutch open condition. Therefore, sufficient time is available for the clutch actuator 114 of the semi-automatic transmission to open the clutch 116 completely and allow smooth change of the gear.
[00026] However during slow/ normal shifts, the gear lever signal 302 does not reach/intersect the offset signal 306 since the delay signal 304 follows the gear lever signal 302 and gets sufficient time to reach the value of gear lever signal 302. The delay signal 304 is equal to the gear lever signal 302. In other words, the gear lever signal 302 reaches the threshold value 308 earlier than reaching the offset signal 306. So the position based threshold value 308 is considered to enable gear disengagement when the gear lever signal 302 reaches the threshold value 308 during slow shifts as shown. Hence, the ECM 110 based on the fast shift or slow shift of the gear lever 104, triggers the clutch open condition. The gear disengagement comprises, sending a signal to the clutch actuator 114 to open the clutch 116, allow the change of gear as requested by the driver, and then again close the clutch 116 through the same clutch actuator 114.
[00027] Fig. 4 illustrates a pattern of gear lever movement to detect a valid shift intention of a driver, according to an embodiment of the present disclosure. The ECM 110 is configured to validate the shift intention or a request of change of gear based on the pattern of movement the gear lever 104. The ECM 110 eliminates the unintentional requests due to various reasons such as vibration, palm resting on the gear lever 104 and the like. If the driver intends to change the gear from 1st gear to 3rd gear, the driver moves the gear lever 104 which is at say 20% position 404 in the 1st gear location, to the extreme end 0% position 402 of the 1st gear location and then brings back and moves towards the Neutral gear 210 followed by moving to the 3rd gear position. Similarly, if the driver intends to change the gear from 4th gear to 5th gear, the driver moves the gear lever 104 which is at say 80% position 406, to the extreme end 100% position 408 of the 4th gear location, and then brings back and moves towards the Neutral gear 210 followed by moving towards the 5th gear location.
[00028] While moving towards the Neutral gear 210, the gear lever signal 302 of the gear lever 104 reaches the threshold value 308 of the respective gear, thereby actuating the clutch 116 to open during normal shifts. Alternatively, the gear lever signal 302 of the gear lever 104 reaches the offset signal 306 earlier than the threshold value 308 of the respective gear, thereby actuating the clutch 116 to open in fast shifts. In the H-type gear layout 102, the 0% position 402 is shown to be extreme end for the odd numbered gears 202 such as 1st gear, 3rd gear, 5th gear and the like. Similarly, the 100% position 408 is shown to be the extreme end position for the even numbered gears 204 such as 2nd gear, 4th gear, 6th gear and the like. Alternatively, the detection of the valid shift intention is also applicable when the odd numbered gears 202 and the even numbered gears 204 are interchanged. Thus, the 0% position is the extreme end position for the even numbered gears 202 and the 100% position is the extreme end position for the odd numbered gears 204.
[00029] In accordance to an embodiment of the present disclosure, the ECM 110 is further adapted to reject detection of unintentional shift due to oscillation of the gear lever 104 at the current gear.
[00030] Fig. 5 illustrates a gear position layout where each gear is provided with individual threshold value for detection of shift intention, according to an embodiment of the present disclosure. Consider a gear layout 102/ configuration where at least one sensor 106 is used to detect the position of the gear lever 104. The acquired signals of the stationary position of the gear lever 104 are normalized to 20% for odd numbered gears 202 i.e. for 1st gear, 3rd gear and a 5th gear, and independent of respective actual positions. Similarly, the even numbered gears 204 i.e. 2nd gear, 4th gear and 6th gear are normalized/ equated to 80%, independent of respective actual positions. And also the Neutral gear 210 normalized/ equated to 50% in each gear lane. Consider a length 520 and length 522 for the location of 2nd gear and the 6th gear respectively, as the actual distance required to move/ travel from the stationary resting position of the gear lever 104 from the current gear location to the Neutral gear 210.
[00031] A clutch open request is triggered when a gear lever 104 is moved from the current gear towards the Neutral gear 210 location, but before reaching the neutral gear 210 location. But due to irregularities, a single and common threshold value 308 for all the three lanes is not sufficient to detect the shift intension from the driver as actual length 520 is not equal to length 522, although the normalized values are same. Thus a very sensitive condition exists to trigger clutch open request for few gear where the clutch open condition is triggered unintentionally due to vibrations of gear lever 104. Also there exists a possibility of a delayed response for clutch open request for few gears where driver feels a reverse force/ notch while shifting the gear.
[00032] In accordance to an embodiment of the present disclosure, an individual threshold value 308 for detection of the shift intention for at least one gear of a gear layout 102 is provided. The individual threshold value 308 is either same for at least two gears or different for all the gears. The individual threshold value 308 is set/ provided for each gear to detect the shift intension from driver when the driver moves the gear lever 104 from the current gear to the Neutral gear 210 or other gear. In accordance to another embodiment of the present disclosure, the threshold values 308 are selected a way higher than vibration or oscillatory values. Thus, the ECM 110 provides sufficient time for the clutch actuator 114 to open the clutch 116 completely whenever there is a request. A method for performing the same is also provided.
[00033] In accordance to another embodiment of the present disclosure, the ECM 110 dynamically adapts the threshold value 308 for detection of a shift intention for each gear during subsequent usage of the gear lever 104. The subsequent use of the gear lever 104 by the driver has the possibility of deteriorating the output values of the at least one sensor 106. Hence, the ECM 110 adapts the new values of the at least one sensor 106 to the resting position of the gear lever 104 at the gear locations in the gear layout 102. The 20% position 404 of the gear lever 104 at the location of the 1st gear is shown by dashed line 502. The 20% position 404 of the gear lever 104 at the location of the 3rd gear is shown by dashed line 506. The 20% position 404 of the gear lever 104 at the location of the 5th gear is shown by dashed line 504.
[00034] Similarly for even numbered gears, the 80% position 406 of the gear lever 104 at the location of the 2nd gear is shown by dashed line 516. The 80% position 406 of the gear lever 104 at the location of the 4th gear is shown by dashed line 514. The 80% position 406 of the gear lever 104 at the location of the 6th gear (reverse gear) is shown by dashed line 518.
[00035] The Neutral gear 210 is also normalized with respect to each gear of the gear layout 102 or for each gear lane. The Neutral gear 210 is normalized to 50% for the first lane as shown by dashed line 510. The Neutral gear 210 is normalized to 50% for the second lane as shown by dashed line 508. The Neutral gear 210 is normalized to 50% for the third lane as shown by dashed line 512.
[00036] Fig. 6 illustrates rejection of unintentional shift due to gear lever oscillations, according to an embodiment of the present disclosure. The ECM 110 is further adapted to reject detection of unintentional shift due to oscillation of the gear lever 104 at the current gear. If the gear lever 104 is worn out or due to vehicle driven in rough roads, there is a possibility of unintentional movement of the gear lever 104 at the respective gear locations. The movement or oscillations of the gear lever 104 lead to opening condition for the clutch 116 even though there is no intention from driver side to shift the gear. The unintentional gear shift is prevented by monitoring the gear lever 104. The standstill position of the gear lever 104 in a gear location is always normalized to 20% (for all gear above the neutral zone) and 80% (for all gear below the neutral zone). The oscillation around the 20% or 80% values are monitored for detecting the oscillation of the gear lever 104.
[00037] For example: Consider a graph with X-axis 310 represents time in suitable units such as milliseconds, and Y-axis 312 represents gear position in percentage. The 50% line corresponds to the Neutral gear and the 20% line corresponds to the normalized resting positon of the gear lever 104 at the respective gear location. Further, the 33% line corresponds to the notch point. If the gear lever 104 in first gear oscillates, then assume the position of gear lever 104 is detected above 20% and below 20%. As seen from the gear lever signal 302, when the gear lever 104 moves from 21% to 19%, a counter is incremented to 1. Then if the gear lever 104 moves back from 19% to 22% then the counter is incremented to 2, and the like. If the counter increments more than or equal to a threshold value set for the counter, then oscillation is confirmed. In the example, after the numeral 4, the oscillation continues and is regarded as oscillation is present. Thereafter, no clutch open condition is enabled until there is no oscillation in the gear lever 104 or a constant movement for a calibration threshold time.
[00038] As shown, the numeral 602 denotes confirmation of oscillation due to the presence of oscillation shown with numeral 5, 6 and 7 even after the numeral 4. Hence, the gear lever signal 302 is not considered for shift intention.
[00039] If the gear lever signal 302 is detected to be constantly moving in one direction such as increasing or decreasing, for a calibrated threshold time, the shift intention detection is enabled. The condition for constant movement is denoted by numeral 604.
[00040] This way oscillations in gear lever in In-Gear position can be detected and clutch open condition can be disabled until there is no oscillation detected.
[00041] Fig. 7 illustrates a method for operating a clutch in a semi-automatic transmission, according to an embodiment of the present disclosure. The method comprises: a step 702 comprising receiving at least one input signal 108 related to position of the gear lever 104. The at least one input signal 108 is received from the at least one sensor 106 installed in proximity of the gear lever 104. A step 704 comprises processing the at least one input signal 108 and generating an offset signal 306. The offset signal 306 is used for detecting a type of shift. A step 706 comprises comparing a value of the at least one input signal 108 with at least one value selected from a group comprising a threshold value 308 of the current gear which is retrieved from a memory element 112 and a generated value of the offset signal 306. A step 708 comprises determining based on the comparison a type of the shift intention as any one selected from a group comprising a fast shift and a normal shift, and operating the clutch 116 accordingly.
[00042] The method further comprises generating the offset signal 306 in dependence of the delay signal 304 obtained by processing the at least one input signal 108. The method still further comprises validating the shift intention based on the pattern of moving the gear lever 104. The pattern of moving comprises moving the gear lever 104 to the extreme end position of the current gear and then bringing towards a desired gear. The method still further comprises operating the clutch 116 after determining a type of shift intention.
[00043] The method still further comprises providing independent threshold value 308 for detecting a shift intention for each gear of the gear layout 102, and further dynamically adapting the threshold value 308 during subsequent usage of the gear lever 104.
[00044] The clutch 116 is opened when the gear lever 104 is moved towards Neutral gear 210 and away from a calibrated threshold value 308 for a current gear, and the clutch 116 is closed when the gear lever 104 is moved away from the Neutral gear 210 and away from the calibrated threshold value 308 for the desired gear.
[00045] In accordance to an embodiment of the present disclosure, an unintentional opening of the clutch 116 or opening condition or shift intention is avoided. The clutch actuator 114 is provided with sufficient time to respond for opening of the clutch 116. The ECM 110 provides an easy to calibrate functionality. The ECM 110 opens the clutch 116 controlled by the clutch actuator 114 only when a shift intension from the driver is detected based on the signals of gear lever 104. Therefore a combination of approaches for clutch open condition for all slow shifts or fast shifts. The ECM 110 provides faster response when the driver actually wants to shift by pulling the gear lever 104. The ECM 110 predicts a very high probability of shifting beforehand and the clutch 116 is already half open based on what torque engine is producing and the response is improved as there less travel of clutch actuator 114 for opening the clutch 116. Also avoiding resistance at the gear lever 104. The gear lever 104 is configurable to a normalized percentage based position other than 20%, such as 10%, 15%, 30% and the like.
[00046] 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.