SE2250417A1 - Clutch controller - Google Patents

Abstract

Systems and methods for controlling a clutch of a vehicle. A rod is coupled to and rotatable with an electric motor in a first direction when the motor is actuated for transitioning the clutch from an engaged configuration to a disengaged configuration. A brake is coupled to the rod. A transition of the clutch from the disengaged configuration to the engaged configuration is initiated, and the rod is rotated in a second direction opposite the first direction responsive to initiating the transition. The brake is applied to the rod using back EMF voltage generated by the motor from the rotation of the rod in the second direction.

Description

CLUTCH CONTROLLER TECHNICAL FIELD[0001] Aspects of this disclosure generally relate to electronic clutch controllers.BACKGROUND[0002] Transitioning a vehicle clutch from a disengaged configuration to an engaged configuration too quickly can result in vehicle damage and inhibit vehicle control.

SUMMARY 3. 3. 3. id="p-3" id="p-3"

[0003] The above summary may present a simplified overview of some aspects of theinvention in order to provide a basic understanding of certain aspects the invention discussedherein. The summary is not intended to provide an extensive overview of the invention, nor is itintended to identify any key or critical elements, or delineate the scope of the invention. The solepurpose of the summary is merely to present some concepts in a simplified form as an introductionto the detailed description presented below. 4. 4. 4. id="p-4" id="p-4"

[0004] In one exemplary embodiment, a method for controlling a clutch of a vehicle usesa system including an electric motor, a rod coupled to and rotatable with the electric motor in afirst direction when the electric motor is actuated for transitioning the clutch from an engagedconfiguration to a disengaged configuration, and a brake coupled to the rod. The methodincludes the steps of actuating the motor and rotating the rod in the first direction to transition theclutch from the engaged configuration to the disengaged configuration, initiating a transition ofthe clutch from the disengaged configuration to the engaged configuration, and rotating the rodin a second direction opposite the first direction responsive to initiating the transition of theclutch from the disengaged configuration to the engaged configuration. The method furtherincludes applying the brake to the rod using back EMF voltage generated by the motor from therotation of the rod in the second direction. . . . id="p-5" id="p-5"

[0005] In a further eXemplary embodiment, a system for controlling a clutch of a vehicleincludes an electric motor, a rod coupled to and rotatable with the motor in a first direction whenthe motor is actuated for transitioning the clutch from an engaged configuration to a disengaged configuration, and a brake coupled to the rod for controlling a rotation of the rod in a second direction opposite the first direction caused by a transition of the clutch from the disengagedconfiguration to the engaged configuration. The system further includes an actuator coupled tothe brake and the motor. The actuator applies the brake to the rod using back EMF Voltage generated by the motor from the rotation of the rod in the second direction.

BRIEF DESCRIPTION OF THE DRAWINGS 6. 6. 6. id="p-6" id="p-6"

[0006] Embodiments of the present inVention will be understood and appreciated morefully from the following detailed description taken in conjunction with the drawings. 7. 7. 7. id="p-7" id="p-7"

[0007] FIG. l is a schematic diagram of an exemplary system for controlling a clutch of aVehicle that shows the clutch in an engaged configuration. 8. 8. 8. id="p-8" id="p-8"

[0008] FIG. 2 is a schematic diagram of the system of FIG. l that shows the clutch in adisengaged configuration. 9. 9. 9. id="p-9" id="p-9"

[0009] FIG. 3 is a schematic diagram of the system of FIG. l that shows a brake of thesystem being applied to control engagement of the clutch. . . . id="p-10" id="p-10"

[0010] FIG. 4 is a schematic diagram of an exemplary system for controlling a clutch of aVehicle that includes a battery powered brake and a back EMF powered brake. 11. 11. 11. id="p-11" id="p-11"

[0011] FIG. 5 is a flowchart of an exemplary method for controlling a clutch of a Vehicle.DETAILED DESCRIPTION[0012] A Vehicle with an electric clutch may include an electric motor for transitioning the clutch from an engaged configuration to a disengaged configuration. Because the clutch may bebiased towards the engaged configuration, the motor may also function to maintain the clutch inthe disengaged configuration until transition back to the engaged configuration is desired, at whichtime power to the motor may be terrninated. HoweVer, an uncontrolled transition of the clutchfrom the disengaged configuration to the engaged configuration may cause the Vehicle to stall,may cause expensive damage to components of the Vehicle and/or clutch, and may place those inand around the Vehicle in dangerous situations. 13. 13. 13. id="p-13" id="p-13"

[0013] For example, if a Vehicle while in motion unexpectedly stalls, a driver traVelingbehind the Vehicle may run into a back end of the Vehicle. As a further example, if a power failureoccurs while the motor is operating to maintain the clutch in the disengaged configuration, such as while the Vehicle is stopped at a light, the clutch may unexpectedly transition to the engaged configuration. An uncontrolled transition to the engaged configuration While the vehicle is stoppedmay cause the vehicle to unexpectedly jump forward, which may pose risks to objects andpedestrians in front of the vehicle, and may place the driver of the vehicle in a dangerous situation,such as if the forward movement causes the vehicle to enter oncoming traffic at an intersection.[0014] FIG. 1 illustrates a system 10 of a vehicle 14 for controlling a clutch 12 of thevehicle 14, such as to provide a controlled movement of the clutch 12 when transitioning from thedisengaged configuration to the engaged configuration. The system 10 may include an electricmotor 16 and a rod 18. The rod 18 may be operatively coupled to and rotatable with the motor 16,and may be operatively coupled to the clutch 12. When the motor 16 is actuated to transition theclutch 12 from an engaged configuration (illustrated in FIG. 1) to a disengaged configuration(illustrated in FIG. 2), the motor 16 may rotate the rod 18 in a direction (hereinafter referred to asa “disengagement direction”) that causes the clutch 12 to disengage. . . . id="p-15" id="p-15"

[0015] The system 10 may further include a battery 20 coupled to and powering the motor16, such as through a power controller 21. The power controller 21 may be configured to controloperation of the motor 16, such as by regulating the voltage and current supplied to the motor 16from the battery 20. The power controller 21 may be a microcontroller or electronic control unit(“ECU”) including a processor, memory, and non-volatile storage including computer-executablesoftware configured, upon execution by the processor, to cause the processor to implement thefunctions, features, and processes of the power controller 21 described herein. 16. 16. 16. id="p-16" id="p-16"

[0016] The motor 16 may include a stator 22 and a rotor 24. The rotor 24 may be coupledto the rod 18, such as via a planetary gear (not shown). The stator 22 may generate a magneticfield that passes through the rotor 24. Upon application of an electrical current to the rotor 24 fromthe battery 20, an interaction between the current through the rotor 24 and the magnetic field ofthe stator 22 may cause the rotor 24 to rotate in the disengagement direction. Correspondingly,the rod 18, which may be rotatable with the rotor 24, may rotate in the disengagement direction.Rotation of the rod 18 in the disengagement direction may place a force (hereinafter referred to asa “disengagement force”) on the clutch 12 that causes the clutch 12 to transition to the disengagedconfiguration. 17. 17. 17. id="p-17" id="p-17"

[0017] More particularly, at least a portion of the rod 18 may include a ball screw 26 thatrotates in the disengagement direction with rod 18. The system 10 may also include a ball nut 28 threaded onto the ball screw 26. Upon rotation of the ball screw 26 in the disengagement direction, the ball nut 28 may move linearly along the length of the ball screw 26. This linear movementmay cause application of the disengagement force onto the clutch 12. 18. 18. 18. id="p-18" id="p-18"

[0018] For example, the system 10 may include a plunger 30 operable to transforrn thelinear movement of the ball nut 28 into the disengagement force onto the clutch 12. The plunger30 may be coupled to and/or wrapped around the rod 18, and may be biased away from the ballnut 28 by a spring 32. The spring 32 may be wrapped around the rod 18 between the ball nut 28and the plunger 30. Like the ball nut 28, the plunger 30 may be linearly moveable along the lengthof the rod 18. 19. 19. 19. id="p-19" id="p-19"

[0019] The plunger 30 may include a spring-loaded pin 34 that corresponds to a detent 36in the rod 18. The detent 36 may receive the pin 34 of the plunger 30 when the plunger 30 is at aparticular linear position along the length of the rod 18. The pin 34 and detent 36 may releasablylock the plunger 30 at the particular linear position of the rod 18. This releasable lock may preventlinear movement of the plunger 30 until an adequate force is applied to the plunger 30, such as bythe ball nut 28, to cause a transition of the clutch 12 from the engaged configuration to thedisengaged configuration. The pin 34 and detent 36 may also prevent the plunger 30, andcorrespondingly the ball nut 28, from moving past a particular linear position along the rod 18when the clutch 12 transitions from the disengaged configuration to the engaged configuration.[0020] The plunger 30 may be coupled to a clutch lever 38, such as via a pushrod 40. Moreparticularly, the plunger 30 may be coupled to an end 42 of the clutch lever 38 via the pushrod 40.An end 44 of the clutch lever 38 opposite the end 42 may be coupled to the clutch 12. The clutchlever 38 may include a pivot point 46 between the two ends 42, 44. 21. 21. 21. id="p-21" id="p-21"

[0021] Rotation of the rod 18 in the disengagement direction may cause the ball nut 28 tomove linearly along the length of the rod 18 towards the plunger 30. This movement may compressthe spring 32 and increase a linear force applied to the plunger 30. As the spring 32 continuescompressing from the linear movement of the ball nut 28 caused by continued rotation of the rod18 in the disengagement direction, the linear force applied to the plunger 30 may overcome thereleasable lock formed by the pin 34 and detent 36. The plunger 30 may correspondingly beginmoving linearly along the length of the rod 18 in a same direction as the ball nut 28. Thismovement of the plunger 30 may cause the plunger 30 to apply a force, such as a push force, on the end 42 of the clutch lever 38 via the pushrod 40. The force applied to the end 42 of the clutch lever 38 may cause the clutch lever 38 to pivot around the pivot point 46, and cause the end 44 ofthe clutch lever 38 to apply a corresponding disengagement force on the clutch 12. 22. 22. 22. id="p-22" id="p-22"

[0022] The clutch l2 may include a flywheel 48, a clutch plate 50, a pressure plate 52, anda biasing element 54 such as a diaphragm spring. Absent application of the disengagement forceon the clutch l2, the biasing element 54 may be configured to bias the clutch l2 towards theengaged configuration. Specifically, absent the disengagement force, the biasing element 54 maybe configured to bias the pressure plate 52 towards the flywheel 48. The pressure plate 52 maycorrespondingly cause the clutch plate 50 to contact the flywheel 48, and a holding force, such asa frictional holding force, may form therebetween. 23. 23. 23. id="p-23" id="p-23"

[0023] When the clutch l2 is in the engaged configuration, the clutch plate 50 may berotatable with the flywheel 48 via the holding force therebetween. The flywheel 48 may becoupled to and rotatable with an engine 56 of the vehicle l4, and the clutch plate 50 may be coupledto the transmission 58 of the vehicle l4, which may be rotatable with the clutch plate 50. Hence,when the clutch l2 is in the engaged configuration, rotations of the flywheel 48 generated by theengine 56 may be translated to the transmission 58 via the holding force between the flywheel 48and the clutch plate 50. 24. 24. 24. id="p-24" id="p-24"

[0024] Referring to FIG. 2, responsive to rotation of the rod l8 in the disengagementdirection, the end 44 of the clutch lever 38 may apply the disengagement force to the biasingelement 54. The disengagement force may cause the biasing element 54 to release the pressureplate 52, and correspondingly the clutch plate 50, from the flywheel 48. For example, when thebiasing element 54 is a diaphragm spring, the end 44 of the clutch lever 38 may apply a push forceto the middle of the spring, which may cause the peripheral of the spring to flex away from theflywheel 48. The pressure plate 52, which may be sandwiched between the peripheral of the springand the flywheel 48, and/ or may be coupled to the peripheral of the spring, may correspondinglymove away from the flywheel 48. Absent the holding force provided by the pressure plate 52, theclutch plate 50 may separate from flywheel 48, thereby eliminating the holding force between theflywheel 48 and the clutch plate 50. The clutch l2 may then be considered as being in thedisengaged configuration, in which rotations of the flywheel 48 generated by the engine 56 maynot be translated to the transmission 58 via a holding force between the flywheel 48 and the clutchplate 50. . . . id="p-25" id="p-25"

[0025] After the clutch 12 has transitioned to the disengaged configuration, the powercontroller 21 may continue actuating the motor 16 to maintain the clutch 12 in the disengagedconfiguration. Specifically, the power controller 21 may continue actuating the motor 16 to applytorque on the rod 18 in the disengagement direction that correspondingly continues the applicationof the disengagement force on the clutch 12. When a transition of the clutch 12 from thedisengaged configuration back to the engaged configuration is desired, the power controller 21may be conf1gured to stop or reduce actuation of the motor 16, which may correspondingly removeor reduce the disengagement force from the clutch 12. The predisposition of the clutch 12 towardsthe engaged configuration may then cause the clutch 12 to retum to the engaged configuration.During this transition, the clutch 12 may apply a force onto the end 44 of the clutch leVer 38, whichmay cause the clutch leVer 38 to piVot back around the piVot point 46, and correspondingly causethe end 42 to apply a substantially linear force on the plunger 30, such as Via the pushrod 40.[0026] In response to receiVing the linear force from the clutch leVer 38, the plunger 30may moVe linearly back along the length of the rod 18 towards the ball nut 28. As the plunger 30moVes linearly towards the ball nut 28, the plunger 30 may apply a linear force against the ball nut28, such as Via the compressed spring 32, that causes the ball nut 28 to moVe linearly along thelength of the rod 18 in a same direction as the plunger 30. The linear moVement of the ball nut 28caused by the engagement of the clutch 12 may be in a direction opposite the moVement of the ballnut 28 during the disengagement of the clutch 12, and may cause the rod 18 to rotate in a direction(hereinafter referred to as an “engagement direction”) that is opposite the disengagement directioncaused by actuation of the motor 16 to disengage the clutch 12. 27. 27. 27. id="p-27" id="p-27"

[0027] As preViously described, allowing the clutch 12 to transition from the disengagedconfiguration to the engaged configuration too quickly may cause the Vehicle 14 to stall, may causedamage to the components of the Vehicle 14 such as the clutch 12, and may place those in andaround the Vehicle 14 in dangerous situations. To help alleViate these issues, the system 10 mayinclude a battery powered brake that provides a torque force on the rod 18 resisting the rotation ofthe rod 18 in the engagement direction, and thus controls, or slows, the transition of the clutch 12from the disengaged to the engaged configuration. For example, the battery powered brake maybe implemented by the power controller 21 and motor 16. When the clutch 12 begins transitioningto the engaged configuration, the power controller 21 may be conf1gured to operate the motor 16 to apply a torque on the rod 18 in the disengagement direction that is less than the force applied on the rod 18 in the engagement direction by the transition of the clutch 12, thereby controlling,or slowing, the engagement transition of the clutch 12. As a further example, the system 10 mayinclude an electromagnetic brake 60 (FIG. 4) coupled to the rod 18. When the clutch 12 istransitioning to the engaged configuration, the power controller 21 may be conf1gured control theelectromagnetic brake 60 to apply a torque on the rod 18 in the disengagement direction that isless than the force applied on the rod 18 in the engagement direction by the transition of the clutch12, thereby controlling, or slowing, the engagement transition of the clutch 12. 28. 28. 28. id="p-28" id="p-28"

[0028] Such battery powered brakes for controlling transitions of the clutch 12 can beproblematic. For example, each of the aforementioned battery powered brakes may rely oncomplex and resource intensiVe software, which may be installed on the power controller 21, forcontrolling the amount of resistiVe force that is applied to the rod 18, and may increase powerconsumption from the battery 20. lnclusion of the electromagnetic brake 60 may also signif1cantlyincrease the size, weight, and cost of the system 10. MoreoVer, in the event of a failure of a batterypowered brake, such as due to a power failure associated with the brake (e. g., failure of the battery20, faulty wiring, or loose connections), the battery powered brake may fail to control the transitionof the clutch 12 to the engaged configuration. 29. 29. 29. id="p-29" id="p-29"

[0029] Thus, in addition or altematiVely to a battery powered brake, the system 10 mayinclude a back electromotiVe force (“EMF”) braking system 61. As described above, the transitionof the clutch 12 from the disengaged conf1guration to the engaged conf1guration may cause arotation of the rod 18 in the engagement direction. The rotation of the rod 18 in the engagementdirection may cause a corresponding rotation of the rotor 24 of the motor 16. Rotation the rotor24 caused by an object extemal to the motor 16, such as the rod 18, may cause the motor 16 tofunction as a generator that generates a Voltage (referred to herein as “back EMF Voltage”). Thesystem 10 may be configured to supply this back EMF Voltage to the actuator 64, which may causethe actuator 64 to apply the brake 62 to the rod 18, and thereby control, or more particularly slow,the engagement transition of the clutch 12. The back EMF braking system 61 may thus be poweredby and operate under control of the back EMF Voltage generated by rotation of the rod 18 in theengagement direction. . . . id="p-30" id="p-30"

[0030] Referring to FIG. 3, the actuator 64 may be configured to receive the back EMFVoltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction, and to apply the brake 62 to the rod 18 based on the back EMF Voltage. Specifically, the back EMF Voltage generated by the motor 16 may cause an electrical current to be directed to the actuator 64.The received current may cause the actuator 64 to apply the brake 62 to the rod 18, which maycorrespondingly place a resistance on the rod 18 that slows the rotation of the rod 18 in theengagement direction. As a result, the transition of the clutch 12 from the disengagedconfiguration to the engaged configuration, the speed of which may be proportional to therotational speed of the rod 18 in the engagement direction, may also be slowed. 31. 31. 31. id="p-31" id="p-31"

[0031] The actuator 64 may control the speed at which the clutch 12 transitions to theengaged configuration by controlling the amount of resistance applied to the rod 18 by the brake62. The amount of resistance applied by the brake 62 Via the actuator 64 may be proportional tothe speed at which the clutch 12 is transitioning to the engaged configuration. In other words, theback EMF braking system 61 may be configured to use the speed of the engaging transition of theclutch 12 as a feedback loop to set the amount of resistance placed on the rod 18 by the brake 62to control the speed of the engagement. In particular, the amount of back EMF Voltage generatedby the motor 16 responsiVe to the clutch 12 transitioning to the engaged configuration may beproportional to the speed of rotation of the rod 18 in the engagement direction, whichcorrespondingly may be proportional to the speed of the engagement of the clutch 12. The amountof back EMF Voltage generated by the motor 16 may thus be proportional to the speed of theengaging transition of the clutch 12. The actuator 64 may be powered by and configured to operatethe brake 62 under control of the back EMF Voltage, and may therefore be configured to apply aresistance to the rod 18 in proportion to the speed of the engaging transition of the clutch 12.[0032] For example, an increase in the speed of an engagement transition of the clutch 12may cause an increase in the generated back EMF Voltage, which correspondingly may cause theactuator 64 to increase resistance applied the rod 18 by the brake 62. Similarly, a decrease in thespeed of an engagement transition of the clutch 12 may cause a decrease in the generated backEMF Voltage, which correspondingly may cause the actuator 64 to decrease the resistance appliedto the rod 18 by the brake 62. Unlike the battery powered brakes discussed above, the actuator 64and brake 62 may be operated and controlled using the back EMF Voltage generated by the motor16 responsiVe to the clutch 12 transitioning to the engaged configuration. The actuator 64 andbrake 62 may thus not be adVersely affected by battery-related power failures, and may not rely on complex, resource intensiVe software. 33. 33. 33. id="p-33" id="p-33"

[0033] The actuator 64 may be a solenoid actuator. The back EMF Voltage may cause thesolenoid actuator to apply a force on the brake 62 that in tum causes the brake 62 to apply aresistance onto the rod 18. The amount of force applied by solenoid actuator on the brake 62 maybe based on the amount of back EMF Voltage generated by the motor 16 from the rotation of therod 18 in the engagement direction and received by the solenoid actuator. 34. 34. 34. id="p-34" id="p-34"

[0034] Specifically, the solenoid actuator may include a solenoid coil 66, a piston 68, anda spring 70. Referring to FIG. 1, the spring 70 may bias the piston 68 to a position in which littleor no force is applied on the brake 62 by the piston 68. Referring to FIG. 3, responsiVe to receiVingback EMF Voltage generated by the motor 16 from the rotation of the rod 18 in the engagementdirection, the solenoid coil 66 may generate a magnetic field that causes the piston 68 to moVe ina direction opposite the bias of the spring 70. The displacement of the piston 68 caused by themagnetic field may apply a corresponding force, such as a corresponding pull force, onto the brake62 that causes the brake 62 to apply resistance to the rod 18. The amount of displacement of thepiston 68, and correspondingly the amount of resistance placed on the rod 18 by the brake 62, maybe proportional to the amount of back EMF Voltage generated by the motor 16 from the rotationof the rod 18 in the engagement direction. Consequently, the faster the speed of the transition ofthe clutch 12 from the disengaged configuration to the engaged configuration, the greaterdisplacement of the piston 68, and the greater amount of resistance that may be applied to the rod18 Via the brake 62. . . . id="p-35" id="p-35"

[0035] The brake 62 may be configured to amplify the force applied from the actuator 64into the resistiVe force applied to the rod 18. In other words, the brake 62 may be configured togenerate a resistiVe force on the rod 18 that is greater than the force applied to the brake 62 by theactuator 64. Consequently, a small amount of back EMF Voltage may cause a relatiVely largeresistance on the rod 18 to control the engaging transition of the clutch 12. When the actuator 64is a solenoid actuator, for example, a small displacement of the piston 68 may cause a relatiVelylarge resistance on the rod 18. This configuration enables a reduction in the power needs of thesystem 10 to adequately control engagement of the clutch 12, allowing the back EMF Voltage tobe a suitable power source. 36. 36. 36. id="p-36" id="p-36"

[0036] The brake 62 may be configured to amplify the force applied by the actuator 64based the Capstan principle. Specifically, the brake 62 may include a length of flexible and/or elastic material, such as that of a spring, forrning one or two or more wraps around the rod 18.

One end of the length of material may be coupled to the actuator 64, such as to an end of the piston68 opposite the end coupled to the spring 70. The other end of the length of material may becoupled to a fixed support object 72, such as the frame of the vehicle 14, that remains substantiallystationary relative to the displacement of the actuator 64 to apply the brake 62 to the rod 18. lnother Words, the fixed support object 72 may hold its coupled end of the brake 62, such as in asubstantially fixed position, When the actuator 64 applies a force onto the other end of the brake62, Which may prevent the brake 62 from unWrapping from the rod 18 responsive to the appliedforce. 37. 37. 37. id="p-37" id="p-37"

[0037] Responsive to the actuator 64 applying a force on the end of the brake 62 coupledto the actuator 64, a corresponding force may be applied onto the other end of the brake 62 coupledto the fixed support object 72 that is opposite the force applied by the actuator 64. By the capstanprinciple, given a force F Pull applied by the actuator 64, the force F Hold exerted on the other endof the brake 62 by the f1xed support object 72 may be given by the following equation: 9038. 9038. 9038. id="p-9038" id="p-9038"

[9038] Fflozd = FpuzzeuznN 39. 39. 39. id="p-39" id="p-39"

[0039] Where ,u is a coefficient of friction between the brake 62 material and the rod 18,and N is the number of times the brake 62 is Wrapped around the rod 18. The force F Hold exertedon the end of the brake 62 opposite the end receiving the force Fpuu from the actuator 64 may thusbe exponentially greater than the force Fpuu applied by the actuator 64. Correspondingly, theresistive torque applied on the rod 18 by the brake 62 may be greater, such as exponentially greater,than the force F Pull applied by the actuator 64. 40. 40. 40. id="p-40" id="p-40"

[0040] The voltage across the motor 16 during the rotation of the rod 18 in the engagementdirection may have an opposite polarity than the voltage across the motor 16 When the poWercontroller 21 is actuating the motor 16 to rotate the rod 18 in the disengagement direction. Theactuator 64 may thus be conf1gured to apply the brake 62 to the rod 18 responsive to the voltageacross the motor 16 having a polarity corresponding to an expected polarity of back EMF voltagegenerated by the motor 16 from the rotation of the rod 18 in the engagement direction, and to notapply or cease application of the brake 62 to the rod 18 responsive to the voltage across the motor16 having a polarity not corresponding the expected polarity of the back EMF voltage generatedby the motor 16 from the rotation of the rod 18 in the engagement direction. 41. 41. 41. id="p-41" id="p-41"

[0041] For example, When the actuator 64 is a solenoid actuator, the actuator 64 may be Wired to the motor 16 such that When the voltage across the motor 16 has a polarity corresponding to the back EMF Voltage generated by the motor 16 from the rotation of the rod 18 in theengagement direction, the piston 68 of the solenoid actuator may displace in a direction that causesthe brake 62 to apply a resistiVe force on the rod 18. Referring to the illustrated embodiment, thepiston 68 may move to compress the spring 70. Altematively, when the Voltage across the motor16 has a polarity that does not match the expected polarity of the back EMF Voltage generated bythe motor 16 from rotation of the rod 18 in the engagement direction, the piston 68 may locate toa position in which the brake 62 does not apply a substantial resistiVe force to the rod 18. Referringto the illustrated embodiment, the piston 68 may moVe towards the rod 18 and/or brake 62.[0042] The system 10 may maintain a persistent connection between the motor 16 and theactuator 64 while the Vehicle 14 is being operated, such that the actuator 64 is continuously enabledto manipulate the brake 62 during operation of the Vehicle 14. AlternatiVely, to preVentunnecessary and potentially damaging moVements of the actuator 64, such as when the clutch 12is transitioning to the disengaged configuration, the system 10 may be configured to enable theactuator 64 to manipulate the brake 62 responsiVe to occurrence of a predefined condition. Forinstance, the system 10 may be configured to enable the brake 62 and actuator 64 responsiVe therod 18 rotating in the engagement direction. As a further instance, the system 10 may beconfigured to enable the brake 62 and actuator 64 responsiVe to a rotation of the rod 18 in theengagement direction satisfying a predefined condition, such as a condition that indicates amalfunction. For example, if a power failure occurs while the power controller 21 is actuating themotor 16 to maintain the clutch 12 in the disengaged configuration, such as while the Vehicle 14is stopped, or if a power failure occurs preVenting a battery powered brake from controlling atransition of the clutch 12 to the engaged configuration, the system 10 may be configured to enablethe brake 62 and actuator 64 to control the transition of the clutch 12 from the disengagedconfiguration to the engaged configuration to preVent the clutch 12 from engaging too quickly,and possibly causing damage to the clutch 12 components or causing the Vehicle 14 tounexpectedly jump forward and/or stall. 43. 43. 43. id="p-43" id="p-43"

[0043] To this end, the system 10 may include a switch controller 74. The switch controller74 may include a switch 76 coupled to the motor 16 and the actuator 64. The switch 76 may beimplemented by a pair of transistors. The switch controller 74 may be configured to monitor forthe predefined condition. While the predefined condition is not satisfied, the switch controller 74 may be configured to maintain the switch 76 in an open state, as illustrated in FIGS. 1 and 2. When 11 the switch 76 is in the open state, the actuator 64 may be blocked from receiving an electricalcurrent corresponding to the back EMF voltage generated by the motor 16 from the rotation of therod 18 in the engagement direction. The actuator 64 may thus not be powered to apply the brake62, which may correspondingly be considered as non-active during this time. 44. 44. 44. id="p-44" id="p-44"

[0044] Conversely, responsive to deterrnining that the predefined condition is satisfied, theswitch controller 74 may be conf1gured to enable the actuator 64 by closing the switch 76, asillustrated in FIGS. 3 and 4. When the switch 76 is in the closed state, the actuator 64 may receivean electrical current corresponding to the back EMF Voltage generated by the motor 16 from therotation of the rod 18 in the engagement direction, which may enable and control the actuator 64to apply the brake 62 as described above. 45. 45. 45. id="p-45" id="p-45"

[0045] The switch controller 74 may be implemented in hardware, software, or both. Forexample, the switch controller 74 include a microcontroller or ECU including a processor,memory, and non-volatile storage including computer-executable software conf1gured, uponexecution by the processor, to cause the processor to implement the functions, features, andprocesses of the switch controller 74 described herein. The switch controller 74 may also be acircuit conf1gured to open and close the switch 76 based on whether signals received by the circuitindicate the predefined condition. The switch controller 74 may be coupled to and powered by thebattery 20. Alternatively, such as to maintain operation of the switch controller 74 upon a failureof the battery 20 to deliver power, the switch controller 74 may include and/or be powered by apower source separate from the battery 20, such as the back EMF voltage generated by the motor16 from the rotation of the rod 18 in the engagement direction and/or a separate battery (e. g., arechargeable intemal battery charged using the back EMF voltage and/ or the battery 20, a sensorbattery). 46. 46. 46. id="p-46" id="p-46"

[0046] The system 10 may further include a sensor that indicates whether the predefinedcondition is satisfied. The switch controller 74 may be coupled to or include the sensor, and maymonitor for satisfaction of the predefined condition based on sensor data generated by the sensor.Responsive to deterrnining that the predefined condition is satisf1ed based on the sensor data, theswitch controller 74 may be conf1gured to enable the actuator 64 to manipulate the brake 62 usingthe back EMF voltage, such as by closing the switch 76. 47. 47. 47. id="p-47" id="p-47"

[0047] For instance and as previously described, the predefined condition may include when the rod 18 begins rotating in the engagement direction. The sensor for indicating whether 12 the predef1ned condition is satisf1ed may thus be a sensor for indicating whether the rod 18 isrotating in the engagement direction, and the switch controller 74 may be configured to determinethat the predef1ned condition is satisf1ed responsive to deterrnining that the rod 18 is rotating in theengagement direction based on the sensor. 48. 48. 48. id="p-48" id="p-48"

[0048] The switch controller 74 may be configured to determine whether the rod 18 isrotating in the engagement direction based on the polarity of the Voltage across the motor 16.When the rod 18 begins rotating in the engagement direction, the polarity of the Voltage across themotor 16 may change to correspond to the expected polarity of back EMF voltage generated fromrotation of the rod 18 in the engagement direction. The sensor for indicating whether the rod 18is rotating in the engagement direction may thus be a voltage sensor coupled to the motor 16, ormore particularly the rotor 24. The sensor may be part of and/or implemented by the switchcontroller 74. Responsive to the polarity of the voltage across the motor 16 corresponding to theexpected polarity of back EMF voltage generated by the motor 16 from rotation of the rod 18 inthe engagement direction, as indicated by the voltage sensor, the switch controller 74 may beconfigured to determine that the rod 18 is rotating in the engagement direction, and to close theswitch 76 accordingly. 49. 49. 49. id="p-49" id="p-49"

[0049] As another example, the sensor for indicating whether the rod 18 is rotating in theengagement direction may be a linear position sensor 80 proximate the rod 18. The linear positionsensor 80 may be configured to indicate a linear position of a tag 82 proximate the linear positionsensor 80 along the rotational axis of the rod 18. The tag 82 may be linearly moveable along thelength of the rod 18 with the rotation of the rod 18 in the engagement direction. For example, thetag 82 may be coupled to and move with the plunger 30. The linear position sensor 80 may indicatea rotational direction of the rod 18 by indicating a direction of linear movement of the tag 82 onthe rotational axis of the rod 18 over time. One movement direction of the tag 82 may correspondto the rod 18 rotating in the engagement direction, and an opposite movement direction of the tag82 may correspond to the rod 18 rotating in the disengagement direction. In the illustratedexample, when the rod 18 rotates in the engagement direction, the linear position sensor 80 mayindicate linear movement of the tag 82 towards the ball nut 28 and the head of the rod 18.Responsive to receiving data from the linear position sensor 80 indicating such linear movement,the switch controller 74 may be configured to determine that the rod 18 is rotating in the engagement direction, and to close the switch 76 accordingly. 13 50. 50. 50. id="p-50" id="p-50"

[0050] The linear position sensor 80 may include one or more hall-effect sensors fortracking a magnetic field generated by the tag 82. AltematiVely, the linear position sensor 80 mayinclude one or more optical sensors for tracking moVement of a unique Visual feature of the tag82, one or more depth sensors for tracking moVement of a particular depth of the tag 82 relatiVe tothe linear position sensor 80, or one or more capacitiVe sensors. 51. 51. 51. id="p-51" id="p-51"

[0051] The sensor for indicating whether the rod l8 is rotating in the engagement directionmay also be a rotation sensor 84. The rotation sensor 84 may be positioned proXimate a sensorring 86 coupled to and rotatable with the rod l8 when the rod l8 rotates in the engagementdirection. The rotation sensor 84 may be conf1gured to indicate a rotational direction of the rod l8by indicating a rotational direction of the sensor ring 86 during the rotation of the rod l8. 52. 52. 52. id="p-52" id="p-52"

[0052] In particular, the sensor ring 86 may include a plurality of tags 88. As rotation ofthe rod l8 causes rotation of the sensor ring 86, the rotation sensor 84 may detect rotationalmoVement of the sensor ring 86 by detecting each time a tag 88 passes by the rotation sensor 84.The rotation sensor 84 may include multiple sub-sensors for deterrnining a rotation direction ofthe sensor ring 86. The sub-sensors may be disposed relatiVe to the sensor ring 86 so that as thesensor ring 86 rotates, a given tag 88 is detected by each sub-sensor before another tag 88 isdetected by one of the sub-sensors. Specifically, the detection zones of the sub-sensors may beseparated by an arc length that is less than half the arc length between the tags 88 on the sensorring 86. Under this arrangement, the switch controller 74 may be conf1gured to determine therotation direction of the sensor ring 86, and correspondingly the rotation direction of the rod l8,based on which of the sub-sensors initially detects each tag 88 as the sensor ring 86 rotates. Similarto the linear position sensor 80, the sensors of the rotation sensor 84 may be hall-effect sensors,optical sensors, or depth sensors for detecting the passage of the tags 88. 53. 53. 53. id="p-53" id="p-53"

[0053] As described aboVe, the predefined condition monitored by the switch controller 74may also include whether rotation of the rod l8 in the engagement direction satisf1es a predefinedcondition. For example, the predefined condition may include when the rotational speed of therod l8 in the engagement direction is greater than a threshold rotational speed. In other words, theswitch controller 74 may be conf1gured to determine that the predefined condition is satisfiedresponsiVe to a speed of rotation of the rod 18 in the engagement direction being greater than thethreshold rotational speed. Because the speed at which the rod l8 rotates in the engagement direction may be proportional to the speed at which the clutch l2 transitions from the disengaged l4 to engaged configuration, this engagement-related condition may indicate that the clutch 12 isengaging too quickly. As previously described, this situation may occur responsive to a powerfailure of a battery powered brake or of the motor 16 when being actuated to maintain the clutch12 in the disengaged configuration. The switch controller 74 may thus be configured to infer amalfunction, such as a power failure, responsive to a rotation of the rod 18 in the engagementdirection being greater than a threshold rotational speed. 54. 54. 54. id="p-54" id="p-54"

[0054] The amount of back EMF voltage generated by the motor 16 from the rotation ofthe rod 18 in the engagement direction may be proportional to the speed of rotation of the rod 18in the engagement direction. The switch controller 74 may thus be configured to determinewhether the rotation of the rod 18 in the engagement direction is greater than a threshold rotationalspeed by deterrnining whether a magnitude of back EMF voltage generated by the motor 16, suchas indicated by a voltage sensor described above, is greater than a threshold magnitude.Responsive to deterrnining that the magnitude of the back EMF voltage is greater than a thresholdmagnitude voltage, the switch controller 74 may be configured to determine that the rotation ofthe rod 18 in the engagement direction satisfies a predef1ned condition. 55. 55. 55. id="p-55" id="p-55"

[0055] The switch controller 74 may also be configured to determine whether a speed ofthe rotation of the rod 18 in the engagement direction is greater than a threshold rotational speedbased on the linear position sensor 80 proximate the rod 18. As previously described, the linearposition sensor 80 may be configured to monitor and indicate a linear position of a tag 82proximate the linear position sensor 80 along the rotational axis of the rod 18. The tag 82 may belinearly moveable along the length of the rod 18 with the rotation of the rod 18 in the engagementdirection. The linear position sensor 80 may indicate a linear speed of the tag 82 during the rotationof the rod 18 in the engagement direction by indicating a linear position of the tag 82 on therotational axis of the rod 18 over time. Because the linear speed of the tag 82 when the rod 18rotates in the engagement direction may be proportional to the speed at which the rod 18 rotates inthe engagement direction, the switch controller 74 may be configured to determine whether therotation of the rod 18 in the engagement direction is greater than a threshold rotational speed bydeterrnining whether the linear speed of the tag 82, as indicated by the linear position sensor 80, isgreater than a threshold linear speed. Responsive to the linear speed of the tag 82 indicated by the linear position sensor 80 being greater than a threshold linear speed, the switch controller 74 may be configured to determine that rotation of the rod l8 in the engagement direction satisf1es apredefined condition. 56. 56. 56. id="p-56" id="p-56"

[0056] The switch controller 74 may further be configured to determine whether a speedof the rotation of the rod l8 in the engagement direction is greater than a threshold rotational speedbased on the rotation sensor 84. As previously described, the rotation sensor 84 may be positionedproximate a sensor ring 86 coupled to and rotatable with the rod l8 when the rod l8 rotates in theengagement direction, and may be configured to indicate a rotational speed of the sensor ring 86during the rotation of the rod l8 in the engagement direction. 57. 57. 57. id="p-57" id="p-57"

[0057] Specifically, as rotation of the rod l8 causes rotation of the sensor ring 86, therotation sensor 84 may detect rotational moVement of the sensor ring 86 by detecting eachoccurrence of a tag 88 passing by the rotation sensor 84. The rotation sensor 84 may thus indicatea rotational speed of the sensor ring 86 by indicating the number of detected rotational moVementsof the sensor ring 86 over time, or more particularly, by indicating the number of tags 88 detectedto moVe past the rotation sensor 84 oVer time. Because the rotational speed of the sensor ring 86may be proportional to the rotational speed of the rod l8 during the rotation of the rod l8 in theengagement direction, the switch controller 74 may be configured to determine whether therotation of the rod l8 in the engagement direction is greater than a threshold rotational speed bydetermining whether the rotational speed of the sensor ring 86 is greater than a threshold rotationalspeed. Responsive to determining that the rotational speed of the sensor ring 86 indicated by therotation sensor 84 is greater than a threshold rotational speed, the switch controller 74 may beconfigured to determine that rotation of the rod l8 in the engagement direction satisf1es apredefined condition. 58. 58. 58. id="p-58" id="p-58"

[0058] When determining whether a rotation of the rod l8 in the engagement directionsatisf1es a predefined condition, the switch controller 74 may or may not be configured to explicitlydetermine whether the rod 18 is rotating in the engagement direction, as described aboVe. Forinstance, the system l0 may be configured such that rotation of the rod l8 in the engagementdirection can be inferred from the existence of the satisfied predefined condition. For example,the rod l8 may primarily rotate at a speed greater than a threshold speed responsiVe to a rotationof the rod l8 in the engagement direction during a malfunction, such as a power failure of a battery powered brake. l6 59. 59. 59. id="p-59" id="p-59"

[0059] The predefined condition monitored for by the switch controller 74 may alsoinclude a condition that anticipates issues when the rod 18 is rotated in the engagement direction,regardless of whether the predefined condition is detected during a rotation of the rod 18 in theengagement direction. As discussed above, the actuator 64 may be conf1gured to only apply thebrake 62 to the rod 18 when the polarity of the Voltage across the motor 16 matches the expectedpolarity of back EMF Voltage generated by the motor 16 from the rotation of the rod 18 in theengagement direction. The predefined condition may thus be irrespective of the rotation of the rod18. As an example, responsive to a battery powered brake of the system 10 malfunctioning, suchas due to a power failure, the battery powered brake may generate and communicate a fault codeto the switch controller 74. For instance, the fault code may be generated by the power controller21, motor 16, or electromagnetic brake 60. The predefined condition may thus include a fault codenotification from a battery powered brake. Responsive to such a fault code, the switch controller74 may be conf1gured do determine that the predefined condition is satisfied, and transition theswitch 76 to a closed state. 60. 60. 60. id="p-60" id="p-60"

[0060] FIG. 5 illustrates a process 100 for controlling a clutch of a vehicle. The process100 may be performed by the system 10, such as by the power controller 21 and the switchcontroller 74, to control the clutch 12 of the vehicle 14. 61. 61. 61. id="p-61" id="p-61"

[0061] In block 102, the clutch 12 may be transitioned to the disengaged configuration. Inparticular, the power controller 21 may actuate the motor 16 to rotate the rod 18 in thedisengagement direction. Rotating the rod 18 in the disengagement direction may cause the clutch12 to transition from the engaged configuration to the disengaged configuration, as describedabove. 62. 62. 62. id="p-62" id="p-62"

[0062] In block 104, the clutch 12 may begin transitioning from the disengagedconfiguration back to the engaged configuration. Specifically, responsive to the clutch 12 beingplaced in the disengaged configuration, the power controller 21 may actuate the motor 16 tocontinue applying torque to the rod 18 in the disengagement direction and thereby maintain theclutch 12 in the disengaged configuration. Thereafter, the motor 16 may cease providing suchmaintaining torque, and the bias of the clutch 12 may begin transitioning the clutch 12 back to theengaged configuration. The power controller 21 may purposefully cause the motor 16 to ceaseproviding the maintaining torque to transition the clutch 12 from the disengaged to the engaged configuration. Altematively, a power failure associated with the motor 16 may occur, such as due 17 to a malfunction of the motor 16, power controller 21, battery 20, or wiring therebetween, whichmay cause the motor 16 to unexpectedly cease providing the maintaining torque on the rod 18.[0063] ln block 106, a deterrnination may be made, such as by the switch controller 74, ofwhether a predefined condition is satisfied. The predefined condition may include one or more ofthe exemplary predefined conditions described above. For instance, the predefined condition mayinclude the rod 18 rotating in the engagement direction, as caused by the transition of the clutch12 from the disengaged to the engaged configuration. In addition or altematively, the predefinedcondition may include rotation of the rod 18 in the engagement direction satisfying a predefinedcondition, such as the rotational speed of the rod 18 being greater than a threshold rotational speed.[0064] For example, deterrnining whether the rotation of the rod 18 in the engagementdirection satisfies a predefined condition may include tracking linear movement of the tag 82 overtime using the linear position sensor 80, such as during the rotation of the rod 18 in the engagementdirection. Thereafter, a linear speed of the tag 82 may be calculated based on the tracked linearmovement over time, and a determination may be made of whether the calculated tag speed isgreater than a threshold tag speed. If so, then a deterrnination may be made that the rotation of therod 18 in the engagement direction satisfies the predefined condition (“Yes” branch of block 106).[0065] As a further example, deterrnining whether the rotation of the rod 18 in theengagement direction satisfies a predefined condition may include tracking rotational movementof the sensor ring 86 over time using the rotation sensor 84, such as during the rotation of the rod18 in the engagement direction. A rotational speed of the sensor ring 86 may then be calculatedbased on the tracked rotational movement of the sensor ring 86 over time. A determination maybe made of whether the rotational speed of the sensor ring 86 is greater than a threshold rotationalspeed. lf so, then a determination may be made that the rotation of the rod 18 in the engagementdirection satisfies the predefined condition (“Yes” branch of block 106). 66. 66. 66. id="p-66" id="p-66"

[0066] Monitoring for occurrence of the predefined condition may continue throughout thetransition of the clutch 12 to the engaged configuration. Responsive to not detecting the predefinedcondition during the transition of the clutch 12 from the disengaged to the engaged configuration(“No” branch of block 106), the process 100 may retum to block 102 in which the clutch 12 isagain transitioned to the disengaged configuration. Responsive to detecting occurrence of thepredefined condition during the transition of the clutch 12 to the engaged configuration (“Yes” branch of block 106), in block 108, the brake 62 may be applied. Specifically, the switch controller 18 74 may be conf1gured to enable the actuator 64 to apply the brake 62 to the rod 18 using the backEMF Voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction,such as by placing the switch 76 in the closed state. 67. 67. 67. id="p-67" id="p-67"

[0067] In block 110, the brake 62 may be adjusted, such as by the actuator 64, during theremainder of the transition of the clutch 12 from the disengaged configuration to the engagedconfiguration to continue controlling the transition of the clutch 12 to the engaged configuration.Specifically, the extent to which the actuator 64 applies the brake 62 to the rod 18 may beproportional to the rotational speed of the rod 18 in the engagement direction, which may beproportional to the amount or magnitude of back EMF Voltage generated by the motor 16 from therotation of the rod 18 in the engagement direction. As the brake 62 applies resistiVe force to therod 18 that slows rotation of the rod 18 in the engagement direction, which in tum slows the speedof the transition of the clutch 12 to the engaged configuration, the motor 16 may generate less backEMF Voltage. Consequently, the actuator 64 may decrease the resistiVe force applied by the brake62 to the rod 18 based on the decreased back EMF Voltage, such as to prevent the clutch 12transition from becoming excessiVely slow. As the rotational speed of the rod 18 thereafterincreases from the decreased resistiVe force applied by the brake 62, the motor 16 may generateincreased back EMF Voltage, which may cause the actuator 64 to increase the resistiVe forceapplied by the brake 62 to the rod 18. Hence, the actuator 64 may be conf1gured to perform cyclesof reducing and increasing the resistiVe force applied to the rod 18 by the brake 62 as a functionof the rotational speed of the rod 18 to maintain the rotation of rod 18 and, correspondingly, thetransition of the clutch 12, near a desired speed. 68. 68. 68. id="p-68" id="p-68"

[0068] Upon the clutch 12 being fully transitioned to the engaged configuration, the rod18 may cease to rotate in the engagement direction. Although the clutch 12 when in the engagedconfiguration may apply a force on the rod 18 in the engagement direction, this force may not beenough to oVercome the releasable lock formed between the pin 34 and detent 36 when the clutch12 transitions to the engaged configuration. Consequently, the rod 18 may cease rotating in theengagement direction, and the motor 16 may stop generating the back EMF Voltage that causes theactuator 64 to apply the brake 62 to the rod 18. Correspondingly, the brake 62 and actuator 64may retum to a position in which the brake 62 is no longer proViding a substantial resistiVe forceto the rod 18. When the actuator 64 is a solenoid actuator, for example, the spring 70 may causethe piston 68 to moVe towards the rod 18 and thereby loosen the brake 62 around the rod 18. 19 69. 69. 69. id="p-69" id="p-69"

[0069] In block 112, a deterrnination may be made, such as by the switch controller 74, ofwhether the clutch 12 has fully transitioned to the engaged configuration, or has again beguntransitioning to the disengaged configuration (block 102), which may occur before the clutch 12is fully transitioned to the engaged configuration. The switch controller 74 may be configured tomake this determination based on sensor data, such as that described above, indicating that therotation of the rod 18 has stopped or changed direction. Responsive to deterrnining that the clutch12 has fully transitioned to the engaged configuration, or is again transitioning to the disengagedconfiguration (“Yes” branch of block 112), in block 114, the back EMF braking system 61 maybe disabled. For example, the switch controller 74 may be configured to disable the back EMFbraking system 61 by placing the switch 76 back in the open position. 70. 70. 70. id="p-70" id="p-70"

[0070] For instance, the switch controller 74 may be configured to determine that theclutch 12 has fully transitioned to the engaged configuration responsive to the magnitude of theback EMF voltage generated by the rod 18 rotating in the engagement direction becoming lessthan a threshold magnitude or zero, to data from the linear position sensor 80 indicating that alinear speed of the tag 82 is less than a threshold speed or zero, and/or to data from the rotationsensor 84 indicating that the rotational speed of the sensor ring 86 is less than a threshold speed orzero. The switch controller 74 may be configured to determine that the clutch 12 has again beguntransitioning to the disengaged configuration responsive to the voltage across the motor 16changing to a polarity that differs from the expected polarity of back EMF voltage generated bythe motor 16 when the rod 18 rotates in the engagement direction, to data from the linear positionsensor 80 indicating a linear movement of the tag 82 in a direction corresponding to rotation of therod 18 in the disengagement direction, and/or data from the rotation sensor 84 indicating rotationalmovement of the sensor ring 86 in the disengagement direction. 71. 71. 71. id="p-71" id="p-71"

[0071] The process 100 illustrated in FIG. 5 is not intended to be limiting. For instance,while the process 100 illustrates determining whether a predefined condition has occurred (block106) after the clutch begins to transition to the engaged configuration (block 104), the switchcontroller 74 may be configured to begin monitoring for and detect predefined conditions uponinitiation of the system 10. For example and as described above, the monitored predefinedcondition may include conditions, such as a generation of a fault code by a battery powered brake,that anticipate issues when the rod 18 rotates in the engagement direction, notwithstanding whether the condition occurs when the rod 18 is rotating in the engagement direction. Because the actuator 64 may be conf1gured to only apply the brake 62 When the rod 18 rotates in the engagementdirection, the switch controller 74 may thus be conf1gured to detect a predef1ned condition, and toresponsively enable the actuator 64 to apply the brake 62 to the rod 18, prior to the clutch 12transitioning to the engaged configuration. 72. 72. 72. id="p-72" id="p-72"

[0072] As described above, uncontrolled transitions of an electric clutch may cause vehicledamage, and may result in dangerous situations for vehicle occupants and those around the vehicle.To thus control transitions of an electric clutch, such as from a disengaged conf1guration to anengaged conf1guration, a vehicle may include a brake operatively coupled to the clutch. The brakemay be powered by back EMF voltage generated by the transition of the clutch from thedisengaged conf1guration to the engaged conf1guration, and may be conf1gured to resist transitionof the clutch to the engaged conf1guration in proportion to the speed at which the clutch transitionsto the engaged configuration. The brake may thus provide a controlled transition of the clutch thatis resistant to battery-related power failures. 73. 73. 73. id="p-73" id="p-73"

[0073] In general, the routines executed to implement the embodiments of the invention,whether implemented as part of an operating system or a specif1c application, component,program, object, module or sequence of instructions, or even a subset thereof, may be referred toherein as "computer program code," or simply "program code." Program code typically comprisescomputer readable instructions that are resident at various times in various memory and storagedevices in a computer and that, when read and executed by one or more processors in a computer,cause that computer to perform the operations necessary to execute operations and/or elementsembodying the various aspects of the embodiments of the invention. Computer readable programinstructions for carrying out operations of the embodiments of the invention may be, for example,assembly language or either source code or object code written in any combination of one or moreprogramming languages. 74. 74. 74. id="p-74" id="p-74"

[0074] Various program code described herein may be identified based upon theapplication within that it is implemented in specif1c embodiments of the invention. However, itshould be appreciated that any particular program nomenclature that follows is used merely forconvenience, and thus the invention should not be limited to use solely in any specific applicationidentif1ed and/ or implied by such nomenclature. Furthermore, given the generally endless numberof manners in which computer programs may be organized into routines, procedures, methods, modules, objects, and the like, as well as the various manners in which program functionality may 21 be allocated among various software layers that are resident Within a typical computer (e.g.,operating systems, libraries, API's, applications, applets, etc.), it should be appreciated that theembodiments of the invention are not limited to the specific organization and allocation of pro gramfunctionality described herein. 75. 75. 75. id="p-75" id="p-75"

[0075] The program code embodied in any of the applications/modules described herein iscapable of being individually or collectively distributed as a program product in a variety ofdifferent forms. In particular, the program code may be distributed using a computer readablestorage medium having computer readable program instructions thereon for causing a processorto carry out aspects of the embodiments of the invention. 76. 76. 76. id="p-76" id="p-76"

[0076] Computer readable storage media, Which is inherently non-transitory, may includevolatile and non-volatile, and removable and non-removable tangible media implemented in anymethod or technology for storage of information, such as computer-readable instructions, datastructures, program modules, or other data. Computer readable storage media may further includeRAM, ROM, erasable programmable read-only memory (EPROM), electrically erasableprogrammable read-only memory (EEPROM), flash memory or other solid state memorytechnology, portable compact disc read-only memory (CD-ROM), or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to store the desired information and Which can be read by acomputer. A computer readable storage medium should not be construed as transitory signals perse (e.g., radio Waves or other propagating electromagnetic Waves, electromagnetic Wavespropagating through a transmission media such as a Waveguide, or electrical signals transmittedthrough a Wire). Computer readable program instructions may be doWnloaded to a computer,another type of programmable data processing apparatus, or another device from a computerreadable storage medium or to an extemal computer or extemal storage device via a network.[0077] Computer readable program instructions stored in a computer readable mediummay be used to direct a computer, other types of programmable data processing apparatus, or otherdevices to function in a particular manner, such that the instructions stored in the computerreadable medium produce an article of manufacture including instructions that implement thefunctions, acts, and/or operations specified in the floWcharts, sequence diagrams, and/or blockdiagrams. The computer program instructions may be provided to one or more processors of a general purpose computer, a special purpose computer, or other programmable data processing 22 apparatus to produce a machine, such that the instructions, Which execute via the one or moreprocessors, cause a series of computations to be performed to implement the functions, acts, and/oroperations specified in the floWcharts, sequence diagrams, and/or block diagrams. 78. 78. 78. id="p-78" id="p-78"

[0078] In certain altemative embodiments, the functions, acts, and/or operations specifiedin the floWcharts, sequence diagrams, and/or block diagrams may be re-ordered, processed serially,and/or processed concurrently consistent With embodiments of the invention. Moreover, any ofthe floWcharts, sequence diagrams, and/or block diagrams may include more or fewer blocks thanthose illustrated consistent With embodiments of the invention. 79. 79. 79. id="p-79" id="p-79"

[0079] The terrninology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the embodiments of the invention. As usedherein, the singular forms "a", "an" and "the" are intended to include the plural forms as Well,unless the context clearly indicates otherwise. It Will be further understood that the terms"comprises" and/or "comprising," When used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations, elements, components, and/orgroups thereof. Furthermore, to the extent that the terms “includes”, “having”, “has”, “Wit ”,“comprised of ,, or variants thereof are used in either the detailed description or the claims, suchterms are intended to be inclusive in a manner similar to the term "comprising". 80. 80. 80. id="p-80" id="p-80"

[0080] While all of the invention has been illustrated by a description of variousembodiments and While these embodiments have been described in considerable detail, it is notthe intention of the Applicant to restrict or in any Way limit the scope of the appended claims tosuch detail. Additional advantages and modif1cations Will readily appear to those skilled in theart. The invention in its broader aspects is therefore not limited to the specific details,representative apparatus and method, and illustrative examples shoWn and described.Accordingly, departures may be made from such details Without departing from the spirit or scope of the Applicant”s general inventive concept. 23

Claims (28)

1. A method for controlling a clutch of a Vehicle using a systern cornprising an electricmotor, a rod coupled to and rotatable With the electric rnotor in a first direction When the electricrnotor is actuated for transitioning the clutch frorn an engaged configuration to a disengagedconfiguration, and a brake coupled to the rod, the rnethod cornprising the steps of: actuating the rnotor and rotating the rod in the first direction to transition the clutch frornthe engaged configuration to the disengaged configuration; initiating a transition of the clutch frorn the disengaged configuration to the engagedconfiguration; rotating the rod in a second direction opposite the first direction responsiVe to initiating thetransition of the clutch frorn the disengaged configuration to the engaged configuration; and applying the brake to the rod using back EMF Voltage generated by the rnotor frorn the rotation of the rod in the second direction.

2. The rnethod of clairn 1, further cornprising:rnonitoring for a predefined condition; and enabling application of the brake to the rod responsiVe to the predefined condition.

3. The rnethod of clairns 1 or 2, further cornprising:deterrnining Whether the rod is rotating in the second direction; andapplying the brake to the rod responsiVe to deterrnining that the rod is rotating in the second direction.

4. The method of any one of clairns 1-3, further cornprising: deterrnining Whether the rotation of the rod in the second direction satisfies a predefinedcondition; and enabling application of the brake to the rod responsiVe to deterrnining that the rotation of the rod in the second direction satisfies the predefined condition.

5. The method of claim 4, wherein the system further includes a battery poweredbrake, and deterrnining whether the rotation of the rod in the second direction satisfies a predefinedcondition comprises determining whether a power failure of the battery powered brake has occurred.

6. The method of claims 4 or 5, wherein deterrnining whether the rotation of the rodin the second direction satisfies a predefined condition comprises determining whether the rotation of the rod in the second direction is at a speed greater than a threshold rotational speed.

7. The method of any one of claims 4-6, wherein deterrnining whether the rotation ofthe rod in the second direction satisfies a predefined condition comprises deterrnining whether amagnitude of the back EMF Voltage generated by the motor from the rotation of the rod in the second direction is greater than a threshold magnitude.

8. The method of any one of claims 4-7, wherein the system further comprises a tagoperatiVely coupled to and linearly moVeable along a rotational axis of the rod with the rotation ofthe rod in the second direction and a linear position sensor proximate the rod that indicates a linearposition of the tag on the rotational axis of the rod during the rotation of the rod in the seconddirection, and deterrnining whether the rotation of the rod in the second direction satisfies apredefined condition comprises: tracking linear moVement of the tag oVer time using the linear position sensor during therotation of the rod in the second direction; calculating a tag speed based on the tracked linear moVement of the tag oVer time; and deterrnining whether the calculated tag speed is greater than a threshold tag speed.

9. The method of any one of claims 4-8, wherein the system further comprises a sensorring coupled to and rotatable with the rotation of the rod in the second direction and a rotationsensor proximate the sensor ring that indicates rotational moVement of the sensor ring, anddeterrnining whether the rotation of the rod in the second direction satisfies a predefined condition comprises: tracking the rotational movement of the sensor ring over time using the rotation sensorduring the rotation of the rod in the second direction; calculating a rotational speed of the sensor ring based on the tracked rotational movementof the sensor ring over time; and determining Whether the rotational speed of the sensor ring is greater than a threshold rotational speed.

10. The method of any one of claims 1-9, Wherein the system further comprises anactuator coupled to the brake, and applying the brake to the rod using the back EMF Voltagegenerated by the motor from the rotation of the rod in the second direction comprises: moving the actuator using the back EMF voltage generated by the motor from the rotationof the rod in the second direction; and applying a first force on the brake by the movement of the actuator.

11. The method of claim 10, Wherein applying the brake to the rod using the back EMFvoltage generated by the motor from the rotation of the rod in the second direction comprisesapplying a second force on the rod by the brake that is greater than the first force and resists rotationof the rod in the second direction responsive to applying the first force on the brake by the movement of the actuator.

12. The method of any one of claims 1-11, Wherein the brake comprises a flexiblematerial forrning a plurality Wraps around the rod, and applying the brake to the rod comprises tightening the Wraps around the rod.

13. The method of any one of claims 1-12, Wherein applying the brake to the rod usingthe back EMF voltage generated by the motor from the rotation of the rod in the second directioncomprises: applying a first force on the rod by the brake based on the back EMF voltage that resistsrotation of the rod in the second direction; and applying a second force on the rod by the brake that resists the rotation of the rod in the second direction and is less than the first force responsive to a decrease in the back EMF voltage.

14. A system for controlling a clutch of a Vehicle, the system comprising: an electric motor; a rod coupled to and rotatable With the motor in a first direction When the motor is actuatedfor transitioning the clutch from an engaged configuration to a disengaged configuration; a brake coupled to the rod for controlling a rotation of the rod in a second direction oppositethe first direction caused by a transition of the clutch from the disengaged configuration to theengaged configuration; and an actuator coupled to the brake and the motor that applies the brake to the rod using back EMF Voltage generated by the motor from the rotation of the rod in the second direction.

15. l5. The system of claim l4, further comprising: a sensor indicating a predefined condition; and a controller coupled to the sensor, actuator, and motor, the controller conf1gured to enablethe actuator to apply the brake using the back EMF Voltage responsiVe to the predefined condition based on the sensor.

16. l6. The system of claims l4 or l5, further comprising: a sensor indicating Whether the rod is rotating in the second direction; and a controller coupled to the sensor, actuator, and motor, the controller conf1gured to enablethe actuator to apply the brake using the back EMF Voltage responsiVe to deterrnining that the rod is rotating in the second direction based on the sensor.

17. l7. The system of any one of claims l4-l6, fiJrther comprising: a sensor indicating Whether the rotation of the rod in the second direction satisf1es apredefined condition; and a controller coupled to the sensor, actuator, and motor, the controller conf1gured to enablethe actuator to apply the brake using the back EMF Voltage responsiVe to deterrnining that the rotation of the rod in the second direction satisf1es the predefined condition based on the sensor.

18. The system of c1aim 17, further comprising a battery powered brake coup1ed to therod, wherein the predefined condition satisfied by the rotation of the ro_d in the second direction comprises a power failure of the battery powered brake.

19. The system of c1aims 17 or 18, wherein the predefined condition satisfied by therotation of the rod in the second direction comprises a speed of the rotation of the rod in the second direction being greater than a thresho1d rotationa1 speed.

20. The system of any one of c1aims 17-19, wherein the predefined condition satisfiedby the rotation of the rod in the second direction comprises a magnitude of the back EMF Voltagegenerated by the motor from the rotation of the rod in the second direction being greater than a thresho1d magnitude.

21. The system of any one of c1aims 17-20, fiJrther comprising: a tag operatiVe1y coup1ed to and 1inear1y moVeab1e a1ong a rotationa1 axis of the rod withthe rotation of the rod in the second direction; and a 1inear position sensor proximate the rod that indicates a 1inear speed of the tag during therotation of the rod in the second direction, wherein the predefined condition satisfied by the rotation of the rod in the second directioncomprises the 1inear speed of the tag indicated by the 1inear position sensor being greater than a thresho1d 1inear speed.

22. The system of any one of c1aims 17-21, fiJrther comprising: a sensor ring coup1ed to and rotatab1e with the rotation of the rod in the second direction;and a rotation sensor proximate the sensor ring that indicates a rotationa1 speed of the sensorring during the rotation of the rod in the second direction, wherein the predefined condition satisfied by the rotation of the rod in the second directioncomprises the rotationa1 speed of the sensor ring indicated by the rotation sensor being greater than a thresho1d rotationa1 speed.

23. The system of any one of claims 14-22, Wherein the actuator comprises a solenoidactuator that applies a force on the brake using the back EMF Voltage generated by the motor from the rotation of the rod in the second direction.

24. The system of claim 23, Wherein the force is a pull force.

25. The system of any one of claims 14-24, Wherein the actuator applies a first force onthe brake responsiVe to receiVing the back EMF Voltage from the motor, and the brake amplif1esthe first force to produce a second force on the rod that resists the rotation of the rod in the second direction responsiVe to receiVing the first force from the actuator.

26. The system of any one of claims 14-25, Wherein the brake comprises a length offlexible material forming a plurality of Wraps around the rod, and the actuator applies the brake to the rod by tightening the Wraps around the rod.

27. The method of any one of claims 1-13, further comprising applying the brake to therod by an actuator to an extent that is proportional to a magnitude of the Back EMF Voltage generated by the motor from the rotation of the rod in the second direction.

28. The system of any one of claims 14-26, Wherein the extent to Which the actuatorapplies the brake to the rod is proportional to a magnitude of the Back EMF Voltage generated by the motor from the rotation of the rod in the second direction.