Claims:We claim:

1. A method for estimating an input shaft speed of a vehicle in absence of an input shaft sensor configured with an input shaft, comprising:
receiving (202), by electronic control unit associated with the input shaft, one or more input signals from a plurality of sensors;
determining (204) an initial input shaft speed based on a speed of the vehicle; and
estimating (206) the input shaft speed based on the one or more input signals and the initial input shaft speed.

2. The method as claimed in claim 1, wherein the plurality of sensors includes a first set of sensors and a second set of sensors, wherein the first set of sensors includes at least one of: a rank position sensor (122), a gear position sensor (120), and a clutch position sensor (124), and wherein the second set of sensors includes at least one of: a gear actuator pressure sensor (410), a gear actuator current sensor (412), and a gear actuator voltage sensor (414).

3. The method as claimed in claim 1, further comprising:
determining (320) a gear shifter position based on the one or more input signals received from a first set of sensors.

4. The method as claimed in claim 3 performs, in response to the determination that the gear shift position is neutral gear,
computing (370) a synchronizer friction torque on the input shaft based on a bearing friction of the input shaft and damping losses;
computing (380) an inertia of the input shaft based on a mass and dimensions of a gear box component; and
estimating (390) the input shaft speed based on the computed torque and inertia, and the initial input shaft speed.

5. The method as claimed in claim 3 performs, in response to the determination that the gear position is not neutral gear,
computing (330) an inertia of the input shaft based on one or more input signals received from the first set of sensors;
computing (340) an actuator force based on one or more input signals received from the second set of sensors;
computing (350), a synchroniser friction torque and an acceleration of a gear shifter mass, based on the actuator force; and
estimating (360) the input shaft speed based on the computed synchronizer friction torque, acceleration of the gear shifter mass, and the inertia.

6. An electronic control unit (600) of a vehicle for estimating an input shaft speed of the vehicle in absence of an input shaft sensor configured with an input shaft, comprising:
a memory (604); and
a processor (606) coupled to the memory (604), wherein the processor (606) is configured to:
receive one or more input signals from a plurality of sensors;
determine an initial input shaft speed based on a speed of the vehicle; and
estimate the input shaft speed based on the one or more input signals and the initial input shaft speed.

7. The system as claimed in claim 6, wherein the plurality of sensors includes a first set of sensors and a second set of sensors, wherein the first set of sensors includes at least one of: a rank position sensor (122), a gear position sensor (120), and a clutch position sensor (124), and wherein the second set of sensors includes at least one of: a gear actuator pressure sensor (410), a gear actuator current sensor (412), and gear actuator voltage sensor (414).

8. The system as claimed in claim 6, wherein the processor (606) is further configured to determine a gear shift position based on the one or more input signals received from a first set of sensors.

9. The system as claimed in claim 8 performs, in response to the determination that the gear position is neutral gear,
compute a synchronizer friction torque on the input shaft based on a bearing friction of the input shaft and damping losses;
compute an inertia of the input shaft based on a mass and dimensions of a gear box; and
estimate the input shaft speed based on the computed torque and inertia, and the initial shaft speed.

10. The system as claimed in claim 8 performs, in response to the determination that the gear position is not neutral gear,
compute an inertia of the input shaft based on one or more input signals received from the first set of sensors;
compute an actuator force based on the one or more input signals received from the second set of sensors;
compute, a synchronizer friction torque and an acceleration of a gear shifter mass, based on the actuator force; and
estimate the input shaft speed based on the computed synchronizer friction torque, acceleration of the gear shifter mass, and the inertia.
, Description:TECHNICAL FIELD

Embodiment of the present disclosure relates to automated manual transmission (AMT) vehicle systems. More particularly, embodiments of the disclosure relate to a method and system for estimating an input shaft speed for AMT in transient vehicle condition.

BACKGROUND

As generally know, an input shaft speed plays crucial role while gear engagement and clutch engagement of automated manual transmission (AMT) vehicle.
During normal operation, the input shaft speed is determined based on either a vehicle speed or an engine speed of a vehicle. However, during transient condition for example, when the vehicle is changing from one gear to another gear or when the vehicle is changing from one gear to neutral gear, the input shaft speed doesn’t depend on either of the above.
Conventionally, AMT vehicles uses hardware sensor installed at an input shaft to measure the input shaft speed. However, the cost involved in measuring the input shaft speed from the hardware sensor is very high.

Hence, there is a need for determining cost efficient solution, easy to implement and also to measure input shaft speed during transient condition.

SUMMARY

The features and advantages realized through the techniques of the present disclosure are brought out. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

One or more shortcomings of the prior art are overcome, and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In an embodiment, the present disclosure discloses a method for estimating an input shaft speed where input shaft sensor is not fitted with the input shaft of the vehicle. The method may include receiving one or more input signals, determining an initial input shaft speed, and estimating the input shaft speed based on the received one or more input signals and the initial input shaft speed.

In another embodiment, the present disclosure discloses an electronic control unit for estimating an input shaft speed of a vehicle in absence of an input shaft sensor configured with an input shaft, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to: receive one or more input signals from a plurality of sensors; determine an initial input shaft speed based on a speed of the vehicle; and estimate the input shaft speed based on the one or more input signals and the initial input shaft speed.

It is to be understood that the aspects and embodiments of the invention described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the invention.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the appended claims. The embodiments of the disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which.

Figure 1 illustrates a block diagram representation of hardware architecture of an automated manual transmission vehicle for an estimation of an input shaft speed;

Figure 2 shows a flowchart illustrating a method for estimating an input shaft speed in accordance with some embodiment of the present disclosure;

Figure 3 shows a flowchart illustrating a method for estimation of an input shaft speed, in accordance with an embodiment of the present disclosure;

Figure 4 shows a flowchart illustrating a method for estimation of an input shaft speed during gearshift, in accordance with an embodiment of the present disclosure;

Figure 5 shows a flowchart illustrating a method for estimation of an input shaft speed during gear is in neutral and clutch is open, in accordance with an embodiment of the present disclosure; and

Figure 6 illustrates a block diagram of a computing system, in accordance with some embodiments of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The terms “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise.

The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise. A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

Figure 1 illustrates a block diagram representation of hardware architecture of an automated manual transmission (AMT) vehicle for an estimation of an input shaft speed, in accordance with an embodiment of the present disclosure.

As shown in fig. 1, the automated manual transmission (AMT) vehicle comprises a transmission control unit (TCU) 102, an input shaft speed estimation module 104, an engine 106, a clutch 108 attached to the engine 106, an input shaft 110 connected to the clutch 108 and the engine 106, an output shaft 112, a gear motor 114, a rank motor 116, a plurality of tires 118, a plurality of sensors that include a gear position sensor 120, a rank position sensor 122, and a clutch position sensor 124, gear actuator sensors 126 that include at least one sensor, and a differential 130.

The Input Shaft Speed Estimation Module 104 estimates the input shaft speed during transient condition based on output from the gear position sensor 120, the rank position sensor 122, the clutch position sensor 124, gear actuator sensors 126, and one or more signals from the transmission control unit (TCU) 102.

A combination of the gear motor 114 and the rank motor 116 is used to operate the vehicle in a particular gear. A combination of output from the gear position sensor 120 and output from the rank position sensor 122 are used to find a gear shifter position in combination with an output from the clutch position sensor 124. In an exemplary embodiment when the gear position sensor 120 output is 1 and when the rank position sensor 122 output is 1, it is determined that the vehicle is operating in first gear. In another exemplary embodiment when the gear position sensor 120 output is 2 and when the rank position sensor 122 output is 2, it is determined that the vehicle is operating in neutral gear. In some embodiments, the gear position sensor 120, the rank position sensor 122, and the clutch position sensor 124 includes potentiometer based sensors. In some embodiments, the gear position sensor 120, the rank position sensor 122, and the clutch position sensor 124 includes variable frequency sensors.

Figure 2 shows a flowchart illustrating a method for estimating an input shaft speed. The example flow diagram 200 may include one or more operations/modules as illustrated by blocks 202-206, which represent operations as may be performed in a method, functional modules in a device.

In Fig. 2, blocks 202-206 are illustrated as being performed sequentially, with block 202 first and block 206 last. It will be appreciated however that these blocks may be re-arranged as convenient to suit particular embodiments and that these blocks or portions thereof may be performed concurrently in some embodiments. It will also be appreciated that in some examples various blocks may be eliminated, divided into additional blocks, and/or combined with other blocks.

At a “Receive input signals from sensors” block 202, the one or more signals from the plurality of sensors are received, the received one or more signals are from the plurality of sensors may be used to estimate an input shaft speed in an absence of an input shaft sensor; block 202 may be followed by block 204.

At a “Determine initial input shaft speed” block 204, an initial input shaft speed is determined, the initial input shaft speed may be determined by use of a vehicle speed or an engine speed of the vehicle; block 204 may be followed by block 206.

At a “Estimate Input Shaft Speed” block 206, the input shaft speed is estimated, the input shaft speed may be estimated based on output from blocks 204 and 206.

Figure 3 shows a flowchart illustrating a method for estimating an input shaft speed, in accordance with some embodiments of the present disclosure. The example flow diagram may include one or more operations/modules as illustrated by blocks 310-360, which represent operations as may be performed in a method, functional modules in a device.

In Fig. 3, blocks 310-370 are illustrated as being performed sequentially, with block 310 first and block 370 last. It will be appreciated however that these blocks may be re-arranged as convenient to suit particular embodiments and that these blocks or portions thereof may be performed concurrently in some embodiments. It will also be appreciated that in some examples various blocks may be eliminated, divided into additional blocks, and/or combined with other blocks.

At a “Receive signal from a plurality of sensors” block 310, signals from a plurality of sensors are received. The plurality of sensors includes a first set of sensors and a second set of sensors. The first set of sensors includes a gear position sensor 120, a rank position sensor 122, and a clutch position sensor 124. In some embodiment, the second set of sensors includes a gear actuator pressure sensor. In some embodiment, the second set of sensors includes at least a gear actuator current sensor, and a gear actuator voltage sensor. In case of hydraulic actuator, the gear actuator pressure sensor can be used. In case of electric actuator, the gear actuator current sensor and the gear actuator voltage sensor may be used; block 310 may be followed by 320.

At a “Determine gear shifter position” decision block 320, a gear shifter position is determined. The output from the first set of sensors are processed to determine the gear shifter position. As explained earlier, the first set of sensors includes a gear position sensor 120, a rank position sensor 122, and a clutch position sensor 124 and based on the relative positions of sensors with respect to the neutral position, gear shifter position is determined. When the gear position sensor 120 output is 1 and the rank position sensor 122 output is 1, it is determined that the vehicle is operating in first gear and when the gear position sensor 120 output is 2 and the rank position sensor 122 output is 2, it is determined that the vehicle is operating in neutral gear.Block 320 may be followed by block 330 when the gear shifter position is determined to be in non- neutral position. In an embodiment, when the gear position sensor 120 output is 1 and when the rank position sensor 122 output is 1, it is determined that the vehicle is operating in first gear i.e., in non-neutral position. Block 320 may be followed by block 370 when the gear shifter position is determined to be in neutral position. In an embodiment, when the gear position sensor 120 output is 2 and when the rank position sensor 122 output is 2, it is determined that the vehicle is operating in neutral gear i.e., in neutral position.

At a “Gear shifter in process of engagement” decision block 330, whether gear shifter in process of engagement or not is determined. When the gear shifter is not in process of engagement then it is processed to block 335 and when the gear shifter is not in process of engagement then it is processed to block 340.

At a “Compute input shaft speed from engine or vehicle speed” block 335, the input shaft speed is computed from engine speed or vehicle speed.

At a “Compute effective inertia from a first set of sensors” block 340, the effective inertia at the input shaft is computed based on the gear shifter position that indicates the gear being engaged. The effective inertia at the input shaft is directly dependent on the gear to be engaged as shown in below equation 1; block 340 may be followed by block 350.

I_(Effec.Input Shaft)= f (Gear to be engaged) ………………. Eq. (1)
At a “Estimate Actuator Force from a second set of sensors” block 350, the actuator force is estimated from a second set of sensors. In some embodiment, output from a gear actuator pressure sensor may be used to estimate force. In some other embodiment, output from a gear actuator current sensor and a gear actuator voltage sensor may be used to estimate force. In case of hydraulic actuator, pressure at the actuator may be translated to force. In case of electromechanical actuator, current consumption and operating voltage may be translated to force; block 350 may be followed by 360.
Force=F_fork=PA
P=Pressure in case of hydraulic system, A =Pressure application area
In case of electromechanical actuator
Current (I)?Torque (T)
F_fork=T/r
r=Radius of rotating system

At a “Compute synchronizer friction torque and acceleration of gear shifter” block 360, the actuator force computed in block 350 may be used to generate synchronizer friction torque and acceleration of gear shifter mass, static synchronizer load; block 360 may be followed by 370.

At a “Estimate Input Shaft Speed” block 370, the input shaft speed is estimated based on initial input shaft speed, the computed torque and effective inertia.

At a “Compute synchronizer friction torque” block 345, the synchronizer friction toque is computed based on bearing friction losses of the input shaft 110 and damping losses of the input shaft 110. When the gear shift position is determined to be in neutral position, the actuator load is based only on bearing friction and damping losses; block 345 may be followed by 355.

At a “Compute inertia at input shaft” block 355, the inertia of the input shaft 110 may be based only on mass and dimensions of a particular AMT gear box and is constant for the particular AMT gear box; block 355 may be followed by block 365.

At a “Estimate input shaft speed” block 365, the input shaft speed is estimated based on synchronizer friction torque and inertia.

Figure 4 illustrates a flow diagram representation for estimation of an input shaft speed during gearshift, in accordance with an embodiment of the present disclosure.

As shown in fig. 4, outputs of a gear position sensor 120, a rank position sensor 122, and a clutch position sensor 124 are processed to block 402 to calculate the gear to be engaged and for calculating effective inertia.

The output of block 402 is the effective inertia, which is used to estimate an input shaft speed. The effective inertia is directly depending on the gear to be engaged as shown in Equation 1.

The outputs from a gear actuator pressure sensor 410, a gear actuator current sensor 412, and a gear actuator voltage sensor 414 are processed to block 404 and to the block 406 to estimate actuator force. In some embodiment, output from the gear actuator pressure sensor 410 can be used to estimate actuator force. In some embodiment, output from the gear actuator current sensor 412 and the gear actuator voltage sensor 414 can be used to estimate actuator force. In case of the hydraulic actuator, pressure at the actuator can be translated to force. In case of the electromechanical actuator, current consumption and operating voltage can be translated to force.

The estimated actuator force from block 406 is processed to block 407 to calculate acceleration of gear shifter mass and acceleration of static synchronizer load, and to block 408 to calculate a synchronizer friction torque.

The output from block 402, block 407, block 408, and the vehicle speed 416 are provided to block 409 to estimate the input shaft speed 450 by use of below equation 2:

Input Shaft Speed = Ninitial + ?_0^t¦?a dt?, ………………………. Eq. (2)
wherein Ninitial is an initial speed of the input shaft 110,
wherein a is acceleration or deceleration of input shaft 110 and the value of a depends on the ratio of calculated torque and the effective inertia as shown in below equation 3,
i.e., a= t/I_(Effec.Input Shaft) …………………………….………Eq. (3)
wherein t is time of gear shift, and
wherein the calculated torque, as shown in below equation 4, is based on actuator load when the gear is engaged and synchronizer parameters.
i.e., t = f (LoadActuator, Synchronizer Parameters) ………………….Eq. (4)

Figure 5 illustrates a block diagram representation for estimation of an input shaft speed during gear is in neutral and clutch is open, in accordance with an embodiment of the present disclosure.

As shown in fig. 5, outputs of a gear position sensor 120, a rank position sensor 122, and a clutch position sensor 124 are processed to block 510 to identify a gear shifter position and further to determine that a vehicle is in neutral when the gear shifter position is in neutral position. In an exemplary embodiment when the gear position sensor 120 output is 2 and when the rank position sensor 122 output is 2, it is determined that the vehicle is operating in neutral gear. In an exemplary embodiment when the vehicle is operating in neutral gear and when the output of the clutch position sensor 124 is 0, then it is determined that the vehicle transmission condition is in neutral & clutch is open.

The previous input shaft speed 550 is provided to block 520 to compute torque. The torque exerted when the gear shifter position is in neutral is only due to bearing friction losses of input shaft and damping losses. The damping losses occurs as the gear box is submerged in oil, it adds damping to rotational component.

An inertia at input shaft is computed at block 530 from mass and dimension parameters of a particular AMT gearbox components and is constant for the particular AMT gear box.

The output from block 510, block 520, block 530, and the vehicle speed 516 are provided to block 540 to estimate the input shaft speed 550 by use of equation 5:
Input Shaft Speed = Ninitial + ?_0^t¦?a dt?, …………………………… Eq. (5)

wherein Ninitial is an initial speed of the input shaft 110,
wherein a is acceleration or deceleration of input shaft and the value of a depends on the ratio of estimated torque and the effective inertia as shown in equation 6,
i.e., a= t/I ………………………………………Eq. (6)
wherein t is time duration of clutch open and gear is in neutral, and
wherein the estimated torque is based on bearing friction and damping losses,
i.e., t = f (LoadBearing Friction, damping losses)

Figure 6 illustrates a block diagram of a computing system, in accordance with some embodiments of the present disclosure.

The Computing system 600 may include input/output (I/O) interface 602, a memory 604, and at least one central processing unit (“CPU” or “processor”) 606.

The I/O interface 602 is coupled with the processor 606 through which an input signal or/and an output signal is communicated.

The memory 604 may include volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof. The memory 604 stores one or more instructions executable by the at least one processor 606 and is communicatively coupled to the processor 606. The one or more data 608 may be stored within the memory 604.

A processor 606 is configured to estimate an input shaft speed based on the data 608 stored in the memory 604. The processor 606 may be of any type including but not limited to a microprocessor (µP), a microcontroller (µC), a digital signal processor (DSP), or any combination thereof. Processor 604 may include one or more levels of caching, such as a level one cache and a level two cache, a processor core, and registers. The processor core may include an arithmetic logic unit (ALU), a floating-point unit (FPU), or any combination thereof.

The one or more data 608 in the memory 604 is processed by modules 610 of the processor 606. The modules 610 includes control logic of input shaft speed estimation unit 620 and processing unit 622. The processing unit 622 is configured to process the signals from the plurality of sensors to estimate the input shaft speed. In an exemplary embodiment, the computing system 600 may be an electronic control unit.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.