DESC:FIELD OF INVENTION
[001] The present invention generally relates to an automated manual transmission system and more specifically to controlling the operation of the clutch in such transmission system.

BACKGROUND
[002] An internal combustion engine for use in a vehicle converts the chemical energy of the fuel into mechanical energy. The output is through the crankshaft and is in the form of rotational motion, the speed of which is a function of the quantity of the fuel burnt. The engine output is constant and varies within a specified range of RPM. Generally the engine is in either of the ON or OFF states with no arrangement for any other state in between.

[003] Such an output is undesirable when used in a vehicle which must perform a variety of maneuvers during its course of operation including but not limited to launch of the vehicle from rest, operating within the specified range of RPM, during which time there may be a need for the vehicle to travel at a larger range of speeds than offered by the engine on its own, wherein a transmission system becomes advantageous. The transmission may include a plurality of gears for each of the ranges of operation.

[004] Manual and automatic transmission systems for automobiles are known. However, automatic transmissions have tended to use torque converters, which, while enabling smooth vehicle operation, do not offer fuel economy.

[005] An automatic transmission could also use a clutch to connect it to the engine output. Noting the cardinal importance of smooth jerk free vehicle operation to achieve smooth take off, good/desired shift quality and desired wheel torque modulation, there exist control systems which control clutch engagement and disengagement in various ways using various actuation methods including hydraulic actuators; electro-mechanical actuators etc. Mechanical elements are generally used to convert the rotational motion of the electrical actuators into a translational motion required to actuate the clutch. However, a problem can arise when the automobile is moving from rest, the engine crankshaft is rotating at a certain RPM while a driven wheel and the transmission are at rest. When a friction plate clutch, as is typically used, is engaged, given the higher degree of relative RPM of the two shafts, if the clutch plates engage directly, the automobile will experience a sudden acceleration as the rear wheel goes from being in rest to a state of motion. This uncontrolled and sudden engagement of the clutch prevents a smooth launch from rest.

[006] Similarly, when shifting between gears during the operation of the vehicle, there is a need for temporarily disengaging the transmission from the engine and then re-engaging once the gear shift event has concluded, so that the gear shift can take place smoothly. During such events too, direct and uncontrolled engagement of the clutch is undesirable.

OBJECTIVE OF THE INVENTION
[007] The principal objective of this invention is to control clutch operation in an automated manual transmission (AMT) system such that shocks and jerks during clutch engagement and disengagement are minimized. Engagement and disengagement of the clutch may be required for several vehicle operations such as gear shift, take off and general drivability.

SUMMARY OF THE INVENTION:
[008] With the above objective in view, the present invention provides an automated manual transmission system comprising a clutch actuating mechanism; at least one control unit for controlling operation of the clutch actuating mechanism; and a sensor array for monitoring clutch operation and providing an input to the control unit wherein said control unit operates said clutch actuating mechanism in a velocity control phase until said sensor array identifies a pre-defined clutch position state following which said control unit operates said clutch actuating mechanism in a position control phase. Such division of the operation of the clutch actuating mechanism into phases, accounting for a plurality of clutch operating parameters including at least position and velocity, is intended to allow smooth clutch operation, particularly during engagement and disengagement, with minimal shocks and jerks as perceived by the vehicle operator.

[009] While the invention is applicable to different clutch types, a common clutch type is the friction plate clutch having a movable clutch plate and a stationary clutch plate. Clutch engagement occurs when movable clutch plate and stationary clutch plate frictionally engage. Though this occurs over a range of displacement of movable clutch plate relative to the stationary clutch plate conveniently simplified to the following cycle: fully engaged – bite point – fully disengaged –bite point – fully engaged, clutch slip differing throughout this cycle. The control unit may be configured to identify clutch state anywhere in this cycle and correspondingly control the clutch actuating mechanism. The commencement of frictional engagement, at which torque transfer commences, may be defined as the clutch bite point during engagement cycle, similarly define bite point definition for disengagement. Clutch disengagement occurs when the movable clutch plate and stationary clutch plate are released from frictional engagement.

[010] During the position control phase, the control unit controls the clutch actuating mechanism, including a clutch actuator such as an electric motor (though hydraulic or pneumatic drivers could less preferably be used), with respect to a sensor signal corresponding to clutch position, for example through sensing the position of the movable clutch plate. Conveniently, the sensor array includes a clutch position sensor to sense clutch position. The control unit can then control the clutch actuator to move the clutch plate in a desired movement process, such as in a series of discrete steps. Such control should allow fine control over the position of the movable clutch plate to be achieved with the objective of minimizing shocks and jerks.

[011] The control unit advantageously controls the clutch actuator with respect to one or more pre-determined clutch positions or a predetermined clutch position range at which shocks or jerks are more probable to minimize such probability. The clutch bite point range is one such pre-determined clutch position range. A plurality of relevant engine operating parameters and sensors which may advantageously be taken into account in estimating the clutch bite position by including corresponding sensors within the sensor array may be selected from the group consisting of engine speed, vehicle speed, gear position, pedal position.

[012] The position control phase properly conducted, ideally through gradual translational motion of the clutch in discrete steps, allows a slow engagement speed to be achieved, together with smooth, jerk-free operation.

[013] The clutch operation is divided into three main phases namely, a velocity control phase, a position control phase, and a step control phase.

[014] In the velocity control phase, the primary control variable of interest is the velocity of the clutch. The desired velocity of the clutch is derived based on a variety of engine/vehicle states. For example, during a gear shift, the desired velocity of the clutch may be a function of the rider pedal position, vehicle speed, current gear, vehicle acceleration. The velocity control of the clutch ensures that the clutch is controlled in a way so as to achieve the desired velocity. The velocity control phase consists of a feed-forward controller coupled with a PID controller. The feed-forward controller actuates the clutch actuating mechanism based on the value of the desired clutch velocity and the present clutch position. The feed-forward controller is conveniently designed assuming an ideal clutch operating system. It does not contain any feedback methodology. The PID controller works on the error between the desired clutch velocity and the actual clutch velocity. The actual clutch velocity is assumed to be the rate of change of clutch position as obtained from the clutch sensor. The combined effort of the feed-forward and the PID controllers ensures that the clutch is always actuated in accordance to the desired clutch velocity with minimum deviation. As the clutch nears a predetermined target position, the position control phase takes over from the velocity control phase. The position control phase operates on the clutch position as a control variable. The primary objective of the clutch position control phase is to ensure that the clutch is positioned according to a pre-determined target position with minimal deviation and response time. The position control phase of the clutch is implemented by a PID controller.

[015] The step control phase of the clutch is derived from multiple instances of velocity control and position control. Due to mechanical properties of the clutch actuating mechanism, there exists a minimum possible velocity with which the clutch can be actuated. But certain operating conditions of the vehicle may demand that the clutch be actuated slower than the aforementioned minimum velocity. In such cases, a step control phase is implemented. The step control phase uses multiple instances of the velocity control phase and the position control phase so as to allow clutch actuation in steps.

[016] The automated manual transmission system is otherwise conveniently described in the Applicant’s co-pending Indian Patent Application No. 4942/MUM/2015, the contents of which are hereby incorporated herein by reference.

[017] The automated manual transmission system may be mated to various prime movers including internal combustion engines, electric motors and hybrids and combinations thereof. Such prime movers may be used in a range of vehicles including 2, 3 and 4 wheeled vehicles. The automated manual transmission system is particularly advantageously used in scooter type motorcycles.

[018] The automated manual transmission system as described above allows smoother clutch operation with good driveability characteristics as shocks and jerks throughout the transmission are minimized. The control regime also minimizes clutch wear and contributes to automated manual transmission system durability.

BRIEF DESCRIPTION OF THE DRAWINGS
[019] Further scope of applicability of the automated manual transmission system of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. The description is made with reference to the accompanying drawings in which:

[020] Figure 1 shows a side view of a motorcycle showing a sequential automated manual transmission system in accordance with one embodiment of the present invention.

[021] Figure 2 shows an orthogonal view of the sequential automated manual transmission system shown in Figure 1 excluding its protective housing.

[022] Figure 3 is a side view of the sequential automated manual transmission system shown in Figures 1 and 2 and including its protective housing.

[023] Figure 4 is a side sectional view of the sequential automated manual transmission system shown in Figures 1 to 3.

[024] Figure 5 is a plan sectional view of the automated manual transmission system shown in Figures 1 to 4 showing the arrangement of the transmission system and driven wheel.

[025] Figure 6 is a first sectional view of the clutch actuator mechanism used in the automated manual transmission system as shown in Figures 1 to 5.

[026] Figure 7 is a second sectional view of the clutch actuator mechanism used in the automated manual transmission system as shown in Figures 1 to 5.
[027] Figure 8 is a third sectional view of the clutch actuator mechanism used in the automated manual transmission system as shown in Figures 1 to 5.

[028] Figure 9 is a schematic view of the frictional clutch used in the automated manual transmission system as shown in Figures 1 to 5 showing stationary or static plates and moving plates.

[029] Figure 10 is a side view of the automated manual transmission system as shown in Figures 1 to 5.

[030] Figure 11A and 11B is a flowchart explaining the operation and decision making involved in the control strategy

[031] Figure 12 is a schematic graph of torque transmitted through the clutch of the automated manual transmission system as shown in Figures 1 to 5 as a function of clutch travel.

[032] Figure 13 is a schematic graph representing bite point and knee point with reference to clutch travel.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[033] Referring now to Figures 1 to 5, there is shown an automated manual transmission system 10, of non-synchromesh clash mesh type, mounted in a scooter type motorcycle for transmitting power from the crankshaft 200 of a swingably mounted single cylinder internal combustion engine 150 to which it is mated to the rear wheel 300 (as conveniently shown in Figure 1 and 5) with inflatable tyre 300A and rim 300B through a drive chain 90 and, through operation of the transmission system 10, at a desired gear ratio. Cylinder 400 is shown together with its associated con rod 410 connecting its piston to the linkage 415 for providing drive to the crankshaft 200. Magneto 270 is also shown mounted to crankshaft 200. The crankshaft 200 and linkage 415 are mounted within engine crankcase 210. A crankshaft position sensor 200A forming part of a sensor array for transmission system 10 senses engine speed and a vehicle speed sensor 300C senses vehicle speed for input to an electronic transmission control unit.

[034] Rotation of the crankshaft 200 causes rotation of drive sprocket 205 and chain 90. A substantial portion of the chain 90 is enclosed within chain case 220. Chain 90 is lubricated using a lubrication system (not shown).

[035] Transmission system 10 is sufficiently compact to be substantially accommodated within a diameter of a rim of rear wheel 300 with its centre of gravity CG located slightly offset from a longitudinal plane P passing through the centre of rear wheel 300 (as conveniently shown in Figure 5) and substantially above the centre horizontal axis CW of rear wheel 300 (as shown in Figure 1).

[036] More particularly, the gear and clutch actuator mechanisms, G and C, of the transmission system are accommodated substantially within a diameter D of the rim 300B of the driven wheel (i.e. the rear wheel 300). The gear actuator mechanism G includes a gear shift motor 120 positioned above the centre horizontal axis CW of the rear wheel 300. The automated transmission system 10 has a centre of gravity CG located along a centre longitudinal axis of the motorcycle. The centre of gravity CG is positioned substantially above the centre horizontal axis CW of rear wheel 300.

[037] Mounted within transmission housing rear portion 20A is the rotating output sprocket 95 of drive chain 90. The drive sprocket 205 rotates essentially at engine speed so speed reduction, through the transmission system 10 is required. To that end, the output sprocket 95 is engageable with an input shaft 22 rotatably mounted to the rear transmission housing portion 20A, through operation of frictional plate clutch 60 by automatically controlled clutch actuator motor 620, required speed being achieved through establishment of a gear ratio. Transmission system 10 is a multi-shaft sequential transmission system having five gear ratios in the illustrated embodiment, gear trains comprising three gears for each of the input shaft 22 (gears 22a-22c), intermediate shaft 23 (gears 23a-23c) and output shaft 24 (gears 24a-24c). As described above, automated manual transmission system 10 employs a chain drive 90. To facilitate operation of transmission system 10, the direction of rotation of the chain drive 90 is made common with the engine (through crankshaft 200) and the rear wheel 300 by including intermediate shaft 23.

[038] Movement between the gear ratios, in sequential manner, involves a gear shift drive system including a shift drum 40. Angular movement of shift drum 40, by controlled movement on operation of electric gear shift motor 120 (for example. a stepper motor, by the transmission control unit, causes its associated forks 47a-47c to controllably slide along cam grooves 40a- 40c to move each of the gear trains described above into position to establish the required gear ratio under control of a transmission control unit (not shown). Gear position sensor 40E provides an input signal to the control unit.

[039] Construction and operation of transmission system 10 to implement a gear shift is described in further detail in the Applicant’s co-pending Application 4942/MUM/2015, the contents of which are hereby incorporated by reference.

[040] The arrangement of gear shift and clutch actuators, G and C, and especially the motors 120 and 620, within the transmission system will now be described.

[041] The gear shift motor 120 is positioned and connected, by bracket 1204 formed integrally with the crankcase LHS 210B, on an upper outer peripheral surface 1205 of the transmission housing rear portion 20A, thus not occupying space inside the transmission housing 20 which would increase transmission system 10 bulkiness and cost as well. Other portions of the gear shift actuation mechanism must be located inside the transmission housing rear portion 20A. The gear shift motor 120 is also accommodated by a recess 1210 formed in upper portion 1205 of the transmission housing rear portion 20A, the recess 1210 having a profile being complementary with contour/structure of the gear shift motor 120 .

[042] The gear shift motor 120, and its associated drive shaft 121, is positioned at a drive end E of clutch actuating mechanism 619, beyond an end of the drive shaft 621 of clutch actuator motor 620. This position may define one end of the transmission system 10. Transmission of driving force from drive shaft 121 to shift drum 40 is via a reduction gear mechanism (not shown).

[043] Gear shift motor 120 and clutch actuator motor 620 are relatively disposed such that the drive axes CC and GC of each motor are disposed perpendicular to each other providing better maneuverability and better balance.

[044] The clutch actuator motor 620, as shown in Figure 1, is also positioned in a recess 628 of the chain case portion 220 between the axle 250 of rear wheel 200 and the engine (not shown). Recess 628 is shaped to complement the shape of clutch actuator motor 620. This position and inclusion of recess 628 within chain case portion 220 to accommodate the clutch actuation motor 620 reduces bulk and provides improved weight distribution and protection for the clutch actuating mechanism. This location provides better ground clearance and enhanced damage tolerance for the clutch actuator motor 620 as the probability of impacts with an uneven road surface or debris etc. lying on the road is reduced.

[045] The clutch actuation mechanism 619, as described above, comprises an electric clutch actuating motor 620 and a reduction gear train which will now be described in further detail with reference to Figures 8 and 9. The reduction gear train, enclosed by protective transmission housing rear portion 20A, includes a worm gear 622 formed integral with a worm gear shaft 624 itself coupled, at one end to drive shaft 621 of clutch actuating motor 620. A distal end of worm gear shaft 624 can freely rotate in bush 624B. The worm gear 622 engages with a sector gear 623 slidably and rotatably mounted on the co-axial inner diameter of bearing 680 press fitted in the clutch cover 20B of the transmission housing rear portion 20A.. A clutch position sensor 60A, forming a further sensor in the sensor array of transmission system 10, is mounted over the sector gear 623 for sensing angular movement of the sector gear 623 and clutch 60 position. The transmission control unit may derive clutch velocity from clutch position change as a function of time as an input to the control strategy.

[046] The clutch actuation mechanism 619 is arranged such that when clutch actuating motor 620 operates, the drive shaft 621 rotates causing the worm gear shaft 624 and its worm gear 622 to rotate. The sector gear 623, being engaged with worm gear 622 also rotates though full rotation is not necessary to operate the clutch 60 between engaged and disengaged positions using the assembly driven by sector gear 623 as described below. The arrangement is self-locking and allows clutch 60 holding in any position along the clutch 60 travel for an indefinite period of time in clutch motor 620 off condition. This provides more flexibility than in a plate-ball type mechanism where, while it is possible to hold the clutch 60 in a position (i.e. with clutch motor off) with the help of detent mechanisms (such as ball slots), the number of positions is limited by the dimensions of the plate-ball mechanism and number of slots and cannot be changed at will. The clutch actuating motor 620 can also be kept relatively small as centre distance between the worm gear 622 and the screw 641 is small (e.g. small centre distance of 49mm) and small screw 641 diameter (20mm). The arrangement saves the space of stacking the ratio/rotation of the motor drive shaft 621 and the rotation to translation mechanism (sliding screw 641 and its arrangement with respect to clutch cover portion 644A as described above) instead of other layout for e.g. side by side/front to back.

[047] A circlip 629 is provided to confine motion of sector gear 623 within limits. Motion of sector gear 623 need only be sufficient, on conversion from rotation into an axial movement of a push rod 650 through sector gear 623 in directions A to engage and disengage the clutch 60. Push rod 650 is actuated by a sliding screw 641 which must only move axially to maintain the required precision for clutch 60 operation.

[048] Allowance must therefore be made for the following. As the sector gear 623 rotates, the generated torque acts on sliding screw 641. To prevent consequential rotation, the sliding screw 641 includes involute splines 643 for fixing a stopper arm 642 to prevent rotary motion of the sliding screw 641. Stopper arm 642 is guided in slots 644A formed in the clutch cover portion 644, these slots 644A being profiled to avoid rotation of stopper arm 642. Stopper arm 642 is also provided with rollers 629A which rotate inside guide profile 644B to convert sliding friction between guide profile 644B and rollers 629A into rolling friction. This arrangement ensures efficient conversion of rotation of sector gear 623 into axial movement of sliding screw 641 and its associated push rod 650. The worm gear 622 provides a large ratio (66) and it can be made self-locking. The sliding screw 641 can be optimized for required travel and efficiency. In contrast, systems using a sliding screw alone lack such high ratio and have to do away with the self-locking capability or sacrifice screw efficiency. Actuating mechanisms utilizing worm gear alone must use a less efficient means of converting rotary motion into translational motion for clutch actuation (such as plate-ball mechanisms).

[049] A clutch position adjuster 652, threadably connected to sliding screw 641 and fastened into position by locking nut 654, is used to impart the sliding motion of the sliding screw 641 to the push rod 650 which enables axial movement of the clutch 60 between engaged and disengaged positions. The thrust on the sector gear 623 is transmitted through bearing 680 to clutch cover portion 644A allowing efficient operation of clutch 60 to take place. Moreover the clutch actuator mechanism 619, as above described, is sufficiently efficient to produce finer linear movement and more precise control by the control unit. As clutch 60 disengagement loads are higher than engagement loads in this case, axial thrust on worm gear shaft 624 is conveniently caused to act on the clutch cover/ bearing) 624A during clutch 60 engagement. This ensures that the clutch 60 disengagement torque requirement is not augmented by the axial thrust while keeping the clutch actuation mechanism 619 compact and economic as one side of the worm gear shaft 624 can be kept supported on a simple needle roller bearing (NRB)/ bush 624B.

[050] Frictional clutch 60 operation involves relative movement between movable clutch plates 61 and a stationary or static clutch plates 62 as shown in Fig. 9. The static plates 62 are splined with clutch hub 64. The movable clutch plates 61 arrest in clutch housing slots 65.

[051] During clutch 60 engagement, the movable clutch plate (pressure plate) moves towards the stationary plate. During clutch 60 disengagement, the reverse process occurs. Without the control strategy described below, shocks and jerks could occur during clutch operation and the presently described automated manual transmission system 10 allows this to be avoided.

[052] The clutch control strategy may be further understood from the flowchart illustrated in Figure 11A and 11B. At step S1 the process of clutch position and velocity control starts; In Step S2 clutch actuation trigger is received from appropriate means; In step S3 the trigger value is compared with true or not if the condition is true it moves to next step or the process ends; At S4 the target clutch position and the current clutch position are identified. At step S5 the identified target position is compared with the current position. If the position matches then the process moves to next step S6 otherwise it ends. At step S6 the preset target clutch velocity is identified. Feed forward PWM in calculated at the step S7. In step S8 the current clutch velocity is identified. At step S9 the current velocity and target velocity are compared and velocity error is calculated and accordingly feedback PWD is also calculated. In step 10 the feed forward PWD calculated at step S7 and the feedback PWD calculated at step S9 and added and applied to the clutch actuator. In step S11 the current clutch position is again determined. In step 12 the current clutch position is compared with the target clutch position and if the difference is more than the pre-set tolerance value then the process from step S6 is followed again till the difference in position comes within the tolerance limit. If the difference is less than the pre-set tolerance value then the process moves to next step. At step 13 PWM is calculated based on the error in the position calculated at step 12. In step 14 the calculated position control PWM is applied to the actuator. At step 15 the current clutch position is again compared with the target position.

[053] More specifically, and as shown schematically in Figures 12 and 13, clutch full engagement occurs when a movable clutch plate 61 and a stationary clutch plate 62 frictionally engage and, as shown, this occurs over a range of movable clutch plate 61 travel relative to the stationary clutch plate conveniently simplified to the following cycle: fully engaged – bite point – knee point – fully disengaged –bite point – knee point –fully engaged, clutch slip differing throughout this cycle. The knee point is the position of the clutch at which the current torque generated by the engine is wholly transmitted through the clutch.
[054] The transmission control unit is configured to identify clutch state anywhere in this cycle and correspondingly control the clutch actuating mechanism 619. The commencement of frictional engagement, at which torque transfer commences, may be defined as the clutch bite point. Clutch disengagement occurs when the movable clutch plate 61 and stationary clutch plate 62 are released from frictional engagement.

[055] Assuming movement of the clutch 60 towards engagement, the transmission control unit controls the clutch actuating mechanism 619 in a position control phase up until the bite point and a velocity control phase after the bite point. Clutch position is sensed by clutch position sensor 60A which is input to the control unit.

[056] When the control unit determines that bite point has been reached, the clutch actuating mechanism 619 is operated to displace the movable clutch plate 61 in a gradual translational motion with slow engagement speed through a series of discrete displacement steps allowing fine control over the position of the movable clutch plate to be achieved through the biting point range with the objective of minimizing shocks and jerks while facilitating driven and drive shaft speeds to be synchronized.

[057] At the end of the step control phase, the control unit transitions to the velocity control phase – again controlled using a feed-forward and a PID control loop – where the control unit controls the clutch actuating mechanism 619 with respect to a sensor signal corresponding to clutch velocity, (clutch velocity is not sensed but computed from clutch position). The control unit here optimizes operation of the clutch actuating mechanism 619 to minimize the error between the desired clutch velocity and the actual clutch velocity.

[058] Clutch position signals remain an important input. Knowledge of the clutch bite point and the zero-slip position of the clutch is required. The clutch bite point is estimated during every take off of the vehicle. During key off the estimated clutch bite point will be stored in the flash memory of the control unit for use in the control strategy.
[059] This knowledge can help the control unit co-ordinate various functions of the gear shift so as to minimize the gear shift jerk as well as the gear shift time. Also such knowledge can be helpful in improving the take-off / drivability of the vehicle.
[060] Modifications and variations to the automated manual transmission system of the present invention may be apparent to the skilled reader of this disclosure. Such modifications and variations are deemed within the scope of the present invention. ,CLAIMS:We Claim:
1. An automated manual transmission system comprising;
a clutch actuating mechanism;
at least one control unit for controlling operation of the clutch actuating mechanism; and at least one sensor for monitoring clutch operation and providing an input to the control unit wherein said control unit operates said clutch actuating mechanism in a velocity control phase until said sensor identifies a pre-defined clutch position state following which said control unit operates said clutch actuating mechanism in a position control phase.

2. An automated manual transmission system as claimed in claim 1 wherein; the clutch is of any suitable type of clutch including but not limited to a friction plate clutch having at least a movable clutch plate configured to engage with at least a stationary clutch plate.

3. An automated manual transmission system as claimed in claim 2 wherein; the engagement of the movable clutch plate with the stationary clutch plate is defined in at least four stages of friction plate clutch including fully engaged – bite point – fully disengaged –bite point – fully engaged and stored in the control unit.

4. An automated manual transmission system as claimed in claim 3 wherein; the control unit is configured to identify the stage of the friction plate clutch based on the engagement state of the movable clutch plate with the stationary clutch plate using the sensor and correspondingly control the clutch actuating mechanism in either velocity control phase or position control phase.

5. An automated manual transmission system as claimed in claim 4 wherein; the clutch actuating mechanism operates the clutch with a desired velocity calculated by the control unit in the velocity control phase.

6. An automated manual transmission system as claimed in claim 5 wherein; the control unit is configured to calculate the desired velocity based on a variety of engine and/or vehicle states including but not limited to during a gear shift, rider pedal position, vehicle speed, current gear and vehicle acceleration.

7. An automated manual transmission system as claimed in claim 5 wherein; the control unit comprises a feed-forward controller coupled with a PID controller used to combinedly actuate the clutch actuating mechanism wherein; the feed-forward controller actuates the clutch actuating mechanism based on the value of the desired clutch velocity and the present clutch position and the PID controller actuates the clutch actuating mechanism based on the error between the desired clutch velocity and the actual clutch velocity.

8. An automated manual transmission system as claimed in claim 7 wherein; the feed-forward controller is configured to calculate the desired clutch velocity based on a data of an ideal clutch operating system.

9. An automated manual transmission system as claimed in claim 5 wherein; the control unit switches the velocity control phase to a position control phase as the clutch nears a predetermined target position to ensure that the clutch is positioned according to a pre-determined target position.

10. An automated manual transmission system as claimed in claim 9 wherein; the control unit actuates the clutch actuator to move the movable clutch plate in a desired movement process in a series of discrete steps using a PID controller.

11. An automated manual transmission system as claimed in claim 1 wherein; the control unit actuates the clutch actuator in a step control phase when certain operating conditions of the vehicle demand that the clutch be actuated slower than the desired velocity of the clutch and uses multiple instances of the velocity control phase and the position control phase so as to allow clutch actuation in steps.

12. An automated manual transmission system as claimed in claim 1 wherein; the clutch actuating mechanism includes an electric motor to actuate the clutch.

13. An automated manual transmission system as claimed in claim 1 wherein; the control unit is configured to control the clutch actuating mechanism based on at least one engine and/ or vehicle operating parameters and sensors selected from the group including but not limited to engine speed, vehicle speed, gear position, pedal position.

14. A method of operating a clutch comprising steps of
a. sensing the position of the clutch and compare it with the target position stored in a control unit;
b. calculating the target clutch velocity by comparing current position of the clutch and target velocity of the clutch using a feed forward controller of the control unit;
c. actuating the clutch with the calculated target velocity using a clutch actuation mechanism;
d. sensing the current velocity of the clutch and comparing with the target velocity to identify an error in the velocity using a PID controller of the control unit;
e. actuating the clutch actuating means for correcting the actual velocity to minimize said error;
f. continuing the steps from c to e unit the clutch comes near the pre-determined position;
g. identifying the error between actual clutch position and a desired clutch position once the clutch achieves said pre-determined position; and
h. operating the clutch actuating mechanism in a series of discrete steps until said error becomes zero.

15. An automated manual transmission system according to any of the claim above is mated to various types of prime movers including internal combustion engines, electric motors, hybrids or combinations thereof.

16. An automated manual transmission system as claimed in claim 14 wherein; the prime mover with said automated manual transmission is used in a range of vehicles including 2, 3 and 4 wheeled vehicles.