WO2021064449A1

WO2021064449A1 - Clutch controller

Info

Publication number: WO2021064449A1
Application number: PCT/IB2019/058358
Authority: WO
Inventors: Jimmy ENGMAN; Eivind VIKEBØ
Original assignee: Ka Group Ag
Priority date: 2019-10-01
Filing date: 2019-10-01
Publication date: 2021-04-08
Also published as: DE112019007773T5; SE2250417A1

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

[0003] The above summary may present a simplified overview of some aspects of the invention in order to provide a basic understanding of certain aspects the invention discussed herein. The summary is not intended to provide an extensive overview of the invention, nor is it intended to identify any key or critical elements, or delineate the scope of the invention. The sole purpose of the summary is merely to present some concepts in a simplified form as an introduction to the detailed description presented below.

[0004] In one exemplary embodiment, a method for controlling a clutch of a vehicle uses a system including an electric motor, a rod coupled to and rotatable with the electric motor in a first direction when the electric motor is actuated for transitioning the clutch from an engaged configuration to a disengaged configuration, and a brake coupled to the rod. The method includes the steps of actuating the motor and rotating the rod in the first direction to transition the clutch from the engaged configuration to the disengaged configuration, initiating a transition of the clutch from the disengaged configuration to the engaged configuration, and rotating the rod in a second direction opposite the first direction responsive to initiating the transition of the clutch from the disengaged configuration to the engaged configuration. The method further includes applying the brake to the rod using back EMF voltage generated by the motor from the rotation of the rod in the second direction.

[0005] In a further exemplary embodiment, a system for controlling a clutch of a vehicle includes an electric motor, a rod coupled to and rotatable with the motor in a first direction when the 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 disengaged configuration to the engaged configuration. The system further includes an actuator coupled to the 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

[0006] Embodiments of the present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings.

[0007] FIG. 1 is a schematic diagram of an exemplary system for controlling a clutch of a vehicle that shows the clutch in an engaged configuration.

[0008] FIG. 2 is a schematic diagram of the system of FIG. 1 that shows the clutch in a disengaged configuration.

[0009] FIG. 3 is a schematic diagram of the system of FIG. 1 that shows a brake of the system being applied to control engagement of the clutch.

[0010] FIG. 4 is a schematic diagram of an exemplary system for controlling a clutch of a vehicle that includes a battery powered brake and a back EMF powered brake.

[0011] FIG. 5 is a flowchart of an exemplary method for controlling a clutch of a vehicle.

DETAIFED 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 be biased towards the engaged configuration, the motor may also function to maintain the clutch in the disengaged configuration until transition back to the engaged configuration is desired, at which time power to the motor may be terminated. However, an uncontrolled transition of the clutch from 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 in and around the vehicle in dangerous situations.

[0013] For example, if a vehicle while in motion unexpectedly stalls, a driver traveling behind the vehicle may run into a back end of the vehicle. As a further example, if a power failure occurs 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 stopped may cause the vehicle to unexpectedly jump forward, which may pose risks to objects and pedestrians 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 the vehicle 14, such as to provide a controlled movement of the clutch 12 when transitioning from the disengaged configuration to the engaged configuration. The system 10 may include an electric motor 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 the clutch 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 as a “disengagement direction”) that causes the clutch 12 to disengage.

[0015] The system 10 may further include a battery 20 coupled to and powering the motor

16, such as through a power controller 21. The power controller 21 may be configured to control operation of the motor 16, such as by regulating the voltage and current supplied to the motor 16 from 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-executable software configured, upon execution by the processor, to cause the processor to implement the functions, features, and processes of the power controller 21 described herein.

[0016] The motor 16 may include a stator 22 and a rotor 24. The rotor 24 may be coupled to the rod 18, such as via a planetary gear (not shown). The stator 22 may generate a magnetic field that passes through the rotor 24. Upon application of an electrical current to the rotor 24 from the battery 20, an interaction between the current through the rotor 24 and the magnetic field of the 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 as a “disengagement force”) on the clutch 12 that causes the clutch 12 to transition to the disengaged configuration.

[0017] More particularly, at least a portion of the rod 18 may include a ball screw 26 that rotates 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 movement may cause application of the disengagement force onto the clutch 12.

[0018] For example, the system 10 may include a plunger 30 operable to transform the linear movement of the ball nut 28 into the disengagement force onto the clutch 12. The plunger 30 may be coupled to and/or wrapped around the rod 18, and may be biased away from the ball nut 28 by a spring 32. The spring 32 may be wrapped around the rod 18 between the ball nut 28 and the plunger 30. Like the ball nut 28, the plunger 30 may be linearly moveable along the length of the rod 18.

[0019] The plunger 30 may include a spring-loaded pin 34 that corresponds to a detent 36 in the rod 18. The detent 36 may receive the pin 34 of the plunger 30 when the plunger 30 is at a particular linear position along the length of the rod 18. The pin 34 and detent 36 may releasably lock the plunger 30 at the particular linear position of the rod 18. This releasable lock may prevent linear movement of the plunger 30 until an adequate force is applied to the plunger 30, such as by the ball nut 28, to cause a transition of the clutch 12 from the engaged configuration to the disengaged configuration. The pin 34 and detent 36 may also prevent the plunger 30, and correspondingly the ball nut 28, from moving past a particular linear position along the rod 18 when 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. More particularly, 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 clutch lever 38 may include a pivot point 46 between the two ends 42, 44.

[0021] Rotation of the rod 18 in the disengagement direction may cause the ball nut 28 to move linearly along the length of the rod 18 towards the plunger 30. This movement may compress the spring 32 and increase a linear force applied to the plunger 30. As the spring 32 continues compressing from the linear movement of the ball nut 28 caused by continued rotation of the rod 18 in the disengagement direction, the linear force applied to the plunger 30 may overcome the releasable lock formed by the pin 34 and detent 36. The plunger 30 may correspondingly begin moving linearly along the length of the rod 18 in a same direction as the ball nut 28. This movement 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 of the clutch lever 38 to apply a corresponding disengagement force on the clutch 12.

[0022] The clutch 12 may include a flywheel 48, a clutch plate 50, a pressure plate 52, and a biasing element 54 such as a diaphragm spring. Absent application of the disengagement force on the clutch 12, the biasing element 54 may be configured to bias the clutch 12 towards the engaged configuration. Specifically, absent the disengagement force, the biasing element 54 may be configured to bias the pressure plate 52 towards the flywheel 48. The pressure plate 52 may correspondingly cause the clutch plate 50 to contact the flywheel 48, and a holding force, such as a frictional holding force, may form therebetween.

[0023] When the clutch 12 is in the engaged configuration, the clutch plate 50 may be rotatable with the flywheel 48 via the holding force therebetween. The flywheel 48 may be coupled to and rotatable with an engine 56 of the vehicle 14, and the clutch plate 50 may be coupled to the transmission 58 of the vehicle 14, which may be rotatable with the clutch plate 50. Hence, when the clutch 12 is in the engaged configuration, rotations of the flywheel 48 generated by the engine 56 may be translated to the transmission 58 via the holding force between the flywheel 48 and the clutch plate 50.

[0024] Referring to FIG. 2, responsive to rotation of the rod 18 in the disengagement direction, the end 44 of the clutch lever 38 may apply the disengagement force to the biasing element 54. The disengagement force may cause the biasing element 54 to release the pressure plate 52, and correspondingly the clutch plate 50, from the flywheel 48. For example, when the biasing element 54 is a diaphragm spring, the end 44 of the clutch lever 38 may apply a push force to the middle of the spring, which may cause the peripheral of the spring to flex away from the flywheel 48. The pressure plate 52, which may be sandwiched between the peripheral of the spring and the flywheel 48, and/or may be coupled to the peripheral of the spring, may correspondingly move away from the flywheel 48. Absent the holding force provided by the pressure plate 52, the clutch plate 50 may separate from flywheel 48, thereby eliminating the holding force between the flywheel 48 and the clutch plate 50. The clutch 12 may then be considered as being in the disengaged configuration, in which rotations of the flywheel 48 generated by the engine 56 may not be translated to the transmission 58 via a holding force between the flywheel 48 and the clutch plate 50. [0025] After the clutch 12 has transitioned to the disengaged configuration, the power controller 21 may continue actuating the motor 16 to maintain the clutch 12 in the disengaged configuration. Specifically, the power controller 21 may continue actuating the motor 16 to apply torque on the rod 18 in the disengagement direction that correspondingly continues the application of the disengagement force on the clutch 12. When a transition of the clutch 12 from the disengaged configuration back to the engaged configuration is desired, the power controller 21 may be configured to stop or reduce actuation of the motor 16, which may correspondingly remove or reduce the disengagement force from the clutch 12. The predisposition of the clutch 12 towards the engaged configuration may then cause the clutch 12 to return to the engaged configuration. During this transition, the clutch 12 may apply a force onto the end 44 of the clutch lever 38, which may cause the clutch lever 38 to pivot back around the pivot point 46, and correspondingly cause the 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 30 may move linearly back along the length of the rod 18 towards the ball nut 28. As the plunger 30 moves linearly towards the ball nut 28, the plunger 30 may apply a linear force against the ball nut 28, such as via the compressed spring 32, that causes the ball nut 28 to move linearly along the length of the rod 18 in a same direction as the plunger 30. The linear movement of the ball nut 28 caused by the engagement of the clutch 12 may be in a direction opposite the movement of the ball nut 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 direction caused by actuation of the motor 16 to disengage the clutch 12.

[0027] As previously described, allowing the clutch 12 to transition from the disengaged configuration to the engaged configuration too quickly may cause the vehicle 14 to stall, may cause damage to the components of the vehicle 14 such as the clutch 12, and may place those in and around the vehicle 14 in dangerous situations. To help alleviate these issues, the system 10 may include a battery powered brake that provides a torque force on the rod 18 resisting the rotation of the rod 18 in the engagement direction, and thus controls, or slows, the transition of the clutch 12 from the disengaged to the engaged configuration. For example, the battery powered brake may be implemented by the power controller 21 and motor 16. When the clutch 12 begins transitioning to the engaged configuration, the power controller 21 may be configured 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 may include an electromagnetic brake 60 (FIG. 4) coupled to the rod 18. When the clutch 12 is transitioning to the engaged configuration, the power controller 21 may be configured control the electromagnetic brake 60 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.

[0028] Such battery powered brakes for controlling transitions of the clutch 12 can be problematic. For example, each of the aforementioned battery powered brakes may rely on complex and resource intensive software, which may be installed on the power controller 21, for controlling the amount of resistive force that is applied to the rod 18, and may increase power consumption from the battery 20. Inclusion of the electromagnetic brake 60 may also significantly increase the size, weight, and cost of the system 10. Moreover, in the event of a failure of a battery powered brake, such as due to a power failure associated with the brake ( e.g ., failure of the battery 20, faulty wiring, or loose connections), the battery powered brake may fail to control the transition of the clutch 12 to the engaged configuration.

[0029] Thus, in addition or alternatively to a battery powered brake, the system 10 may include a back electromotive force (“EMF”) braking system 61. As described above, the transition of the clutch 12 from the disengaged configuration to the engaged configuration may cause a rotation of the rod 18 in the engagement direction. The rotation of the rod 18 in the engagement direction may cause a corresponding rotation of the rotor 24 of the motor 16. Rotation the rotor 24 caused by an object external to the motor 16, such as the rod 18, may cause the motor 16 to function as a generator that generates a voltage (referred to herein as “back EMF voltage”). The system 10 may be configured to supply this back EMF voltage to the actuator 64, which may cause the 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 powered by and operate under control of the back EMF voltage generated by rotation of the rod 18 in the engagement direction.

[0030] Referring to FIG. 3, the actuator 64 may be configured to receive the back EMF voltage 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 may correspondingly place a resistance on the rod 18 that slows the rotation of the rod 18 in the engagement direction. As a result, the transition of the clutch 12 from the disengaged configuration to the engaged configuration, the speed of which may be proportional to the rotational speed of the rod 18 in the engagement direction, may also be slowed.

[0031] The actuator 64 may control the speed at which the clutch 12 transitions to the engaged configuration by controlling the amount of resistance applied to the rod 18 by the brake 62. The amount of resistance applied by the brake 62 via the actuator 64 may be proportional to the speed at which the clutch 12 is transitioning to the engaged configuration. In other words, the back EMF braking system 61 may be configured to use the speed of the engaging transition of the clutch 12 as a feedback loop to set the amount of resistance placed on the rod 18 by the brake 62 to control the speed of the engagement. In particular, the amount of back EMF voltage generated by the motor 16 responsive to the clutch 12 transitioning to the engaged configuration may be proportional to the speed of rotation of the rod 18 in the engagement direction, which correspondingly may be proportional to the speed of the engagement of the clutch 12. The amount of back EMF voltage generated by the motor 16 may thus be proportional to the speed of the engaging transition of the clutch 12. The actuator 64 may be powered by and configured to operate the brake 62 under control of the back EMF voltage, and may therefore be configured to apply a resistance 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 12 may cause an increase in the generated back EMF voltage, which correspondingly may cause the actuator 64 to increase resistance applied the rod 18 by the brake 62. Similarly, a decrease in the speed of an engagement transition of the clutch 12 may cause a decrease in the generated back EMF voltage, which correspondingly may cause the actuator 64 to decrease the resistance applied to the rod 18 by the brake 62. Unlike the battery powered brakes discussed above, the actuator 64 and brake 62 may be operated and controlled using the back EMF voltage generated by the motor 16 responsive to the clutch 12 transitioning to the engaged configuration. The actuator 64 and brake 62 may thus not be adversely affected by battery-related power failures, and may not rely on complex, resource intensive software. [0033] The actuator 64 may be a solenoid actuator. The back EMF voltage may cause the solenoid actuator to apply a force on the brake 62 that in turn causes the brake 62 to apply a resistance onto the rod 18. The amount of force applied by solenoid actuator on the brake 62 may be based on the amount of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction and received by the solenoid actuator.

[0034] Specifically, the solenoid actuator may include a solenoid coil 66, a piston 68, and a spring 70. Referring to FIG. 1, the spring 70 may bias the piston 68 to a position in which little or no force is applied on the brake 62 by the piston 68. Referring to FIG. 3, responsive to receiving back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction, the solenoid coil 66 may generate a magnetic field that causes the piston 68 to move in a direction opposite the bias of the spring 70. The displacement of the piston 68 caused by the magnetic field may apply a corresponding force, such as a corresponding pull force, onto the brake 62 that causes the brake 62 to apply resistance to the rod 18. The amount of displacement of the piston 68, and correspondingly the amount of resistance placed on the rod 18 by the brake 62, may be proportional to the amount of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction. Consequently, the faster the speed of the transition of the clutch 12 from the disengaged configuration to the engaged configuration, the greater displacement of the piston 68, and the greater amount of resistance that may be applied to the rod 18 via the brake 62.

[0035] The brake 62 may be configured to amplify the force applied from the actuator 64 into the resistive force applied to the rod 18. In other words, the brake 62 may be configured to generate a resistive force on the rod 18 that is greater than the force applied to the brake 62 by the actuator 64. Consequently, a small amount of back EMF voltage may cause a relatively large resistance on the rod 18 to control the engaging transition of the clutch 12. When the actuator 64 is a solenoid actuator, for example, a small displacement of the piston 68 may cause a relatively large resistance on the rod 18. This configuration enables a reduction in the power needs of the system 10 to adequately control engagement of the clutch 12, allowing the back EMF voltage to be a suitable power source.

[0036] The brake 62 may be configured to amplify the force applied by the actuator 64 based the Capstan principle. Specifically, the brake 62 may include a length of flexible and/or elastic material, such as that of a spring, forming 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 piston 68 opposite the end coupled to the spring 70. The other end of the length of material may be coupled to a fixed support object 72, such as the frame of the vehicle 14, that remains substantially stationary relative to the displacement of the actuator 64 to apply the brake 62 to the rod 18. In other words, the fixed support object 72 may hold its coupled end of the brake 62, such as in a substantially fixed position, when the actuator 64 applies a force onto the other end of the brake 62, which may prevent the brake 62 from unwrapping from the rod 18 responsive to the applied force.

[0037] Responsive to the actuator 64 applying a force on the end of the brake 62 coupled to the actuator 64, a corresponding force may be applied onto the other end of the brake 62 coupled to the fixed support object 72 that is opposite the force applied by the actuator 64. By the capstan principle, given a force F_Puu applied by the actuator 64, the force F_Hoid exerted on the other end of the brake 62 by the fixed support object 72 may be given by the following equation:

[0038] F_Hold = F_Pulle^^N

[0039] where m 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_Hoid exerted on the end of the brake 62 opposite the end receiving the force F_Puu from the actuator 64 may thus be exponentially greater than the force F_Puu applied by the actuator 64. Correspondingly, the resistive torque applied on the rod 18 by the brake 62 may be greater, such as exponentially greater, than the force F_Puu applied by the actuator 64.

[0040] The voltage across the motor 16 during the rotation of the rod 18 in the engagement direction may have an opposite polarity than the voltage across the motor 16 when the power controller 21 is actuating the motor 16 to rotate the rod 18 in the disengagement direction. The actuator 64 may thus be configured to apply the brake 62 to the rod 18 responsive to the voltage across the motor 16 having a polarity corresponding to an expected polarity of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction, and to not apply or cease application of the brake 62 to the rod 18 responsive to the voltage across the motor 16 having a polarity not corresponding the expected polarity of the back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction.

[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 the engagement direction, the piston 68 of the solenoid actuator may displace in a direction that causes the brake 62 to apply a resistive force on the rod 18. Referring to the illustrated embodiment, the piston 68 may move to compress the spring 70. Alternatively, when the voltage across the motor 16 has a polarity that does not match the expected polarity of the back EMF voltage generated by the motor 16 from rotation of the rod 18 in the engagement direction, the piston 68 may locate to a position in which the brake 62 does not apply a substantial resistive force to the rod 18. Referring to 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 the actuator 64 while the vehicle 14 is being operated, such that the actuator 64 is continuously enabled to manipulate the brake 62 during operation of the vehicle 14. Alternatively, to prevent unnecessary and potentially damaging movements of the actuator 64, such as when the clutch 12 is transitioning to the disengaged configuration, the system 10 may be configured to enable the actuator 64 to manipulate the brake 62 responsive to occurrence of a predefined condition. For instance, the system 10 may be configured to enable the brake 62 and actuator 64 responsive the rod 18 rotating in the engagement direction. As a further instance, the system 10 may be configured to enable the brake 62 and actuator 64 responsive to a rotation of the rod 18 in the engagement direction satisfying a predefined condition, such as a condition that indicates a malfunction. For example, if a power failure occurs while the power controller 21 is actuating the motor 16 to maintain the clutch 12 in the disengaged configuration, such as while the vehicle 14 is stopped, or if a power failure occurs preventing a battery powered brake from controlling a transition of the clutch 12 to the engaged configuration, the system 10 may be configured to enable the brake 62 and actuator 64 to control the transition of the clutch 12 from the disengaged configuration 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 to unexpectedly jump forward and/or stall.

[0043] To this end, the system 10 may include a switch controller 74. The switch controller

74 may include a switch 76 coupled to the motor 16 and the actuator 64. The switch 76 may be implemented by a pair of transistors. The switch controller 74 may be configured to monitor for the 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 the switch 76 is in the open state, the actuator 64 may be blocked from receiving an electrical current corresponding to the back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction. The actuator 64 may thus not be powered to apply the brake 62, which may correspondingly be considered as non-active during this time.

[0044] Conversely, responsive to determining that the predefined condition is satisfied, the switch controller 74 may be configured to enable the actuator 64 by closing the switch 76, as illustrated in FIGS. 3 and 4. When the switch 76 is in the closed state, the actuator 64 may receive an electrical current corresponding to the back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction, which may enable and control the actuator 64 to apply the brake 62 as described above.

[0045] The switch controller 74 may be implemented in hardware, software, or both. For example, the switch controller 74 include a microcontroller or ECU including a processor, memory, and non-volatile storage including computer-executable software configured, upon execution by the processor, to cause the processor to implement the functions, features, and processes of the switch controller 74 described herein. The switch controller 74 may also be a circuit configured to open and close the switch 76 based on whether signals received by the circuit indicate the predefined condition. The switch controller 74 may be coupled to and powered by the battery 20. Alternatively, such as to maintain operation of the switch controller 74 upon a failure of the battery 20 to deliver power, the switch controller 74 may include and/or be powered by a power source separate from the battery 20, such as the back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction and/or a separate battery ( e.g ., a rechargeable internal battery charged using the back EMF voltage and/or the battery 20, a sensor battery).

[0046] The system 10 may further include a sensor that indicates whether the predefined condition is satisfied. The switch controller 74 may be coupled to or include the sensor, and may monitor for satisfaction of the predefined condition based on sensor data generated by the sensor. Responsive to determining that the predefined condition is satisfied based on the sensor data, the switch controller 74 may be configured to enable the actuator 64 to manipulate the brake 62 using the back EMF voltage, such as by closing the switch 76.

[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 the predefined condition is satisfied may thus be a sensor for indicating whether the rod 18 is rotating in the engagement direction, and the switch controller 74 may be configured to determine that the predefined condition is satisfied responsive to determining that the rod 18 is rotating in the engagement direction based on the sensor.

[0048] The switch controller 74 may be configured to determine whether the rod 18 is rotating 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 the motor 16 may change to correspond to the expected polarity of back EMF voltage generated from rotation of the rod 18 in the engagement direction. The sensor for indicating whether the rod 18 is rotating in the engagement direction may thus be a voltage sensor coupled to the motor 16, or more particularly the rotor 24. The sensor may be part of and/or implemented by the switch controller 74. Responsive to the polarity of the voltage across the motor 16 corresponding to the expected polarity of back EMF voltage generated by the motor 16 from rotation of the rod 18 in the engagement direction, as indicated by the voltage sensor, 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.

[0049] As another example, the sensor for indicating whether the rod 18 is rotating in the engagement direction may be a linear position sensor 80 proximate the rod 18. The linear position sensor 80 may be configured to indicate a linear position of a tag 82 proximate the linear position sensor 80 along the rotational axis of the rod 18. The tag 82 may be linearly moveable along the length of the rod 18 with the rotation of the rod 18 in the engagement direction. For example, the tag 82 may be coupled to and move with the plunger 30. The linear position sensor 80 may indicate a rotational direction of the rod 18 by indicating a direction of linear movement of the tag 82 on the rotational axis of the rod 18 over time. One movement direction of the tag 82 may correspond to the rod 18 rotating in the engagement direction, and an opposite movement direction of the tag 82 may correspond to the rod 18 rotating in the disengagement direction. In the illustrated example, when the rod 18 rotates in the engagement direction, the linear position sensor 80 may indicate 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. [0050] The linear position sensor 80 may include one or more hall-effect sensors for tracking a magnetic field generated by the tag 82. Alternatively, the linear position sensor 80 may include one or more optical sensors for tracking movement of a unique visual feature of the tag 82, one or more depth sensors for tracking movement of a particular depth of the tag 82 relative to the linear position sensor 80, or one or more capacitive sensors.

[0051] The sensor for indicating whether the rod 18 is rotating in the engagement direction may also be a rotation sensor 84. The rotation sensor 84 may be positioned proximate a sensor ring 86 coupled to and rotatable with the rod 18 when the rod 18 rotates in the engagement direction. The rotation sensor 84 may be configured to indicate a rotational direction of the rod 18 by indicating a rotational direction of the sensor ring 86 during the rotation of the rod 18.

[0052] In particular, the sensor ring 86 may include a plurality of tags 88. As rotation of the rod 18 causes rotation of the sensor ring 86, the rotation sensor 84 may detect rotational movement 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 determining a rotation direction of the sensor ring 86. The sub-sensors may be disposed relative to the sensor ring 86 so that as the sensor ring 86 rotates, a given tag 88 is detected by each sub-sensor before another tag 88 is detected by one of the sub-sensors. Specifically, the detection zones of the sub-sensors may be separated by an arc length that is less than half the arc length between the tags 88 on the sensor ring 86. Under this arrangement, the switch controller 74 may be configured to determine the rotation direction of the sensor ring 86, and correspondingly the rotation direction of the rod 18, based on which of the sub-sensors initially detects each tag 88 as the sensor ring 86 rotates. Similar to 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.

[0053] As described above, the predefined condition monitored by the switch controller 74 may also include whether rotation of the rod 18 in the engagement direction satisfies a predefined condition. For example, the predefined condition may include when the rotational speed of the rod 18 in the engagement direction is greater than a threshold rotational speed. In other words, the switch controller 74 may be configured to determine that the predefined condition is satisfied responsive to a speed of rotation of the rod 18 in the engagement direction being greater than the threshold rotational speed. Because the speed at which the rod 18 rotates in the engagement direction may be proportional to the speed at which the clutch 12 transitions from the disengaged to engaged configuration, this engagement-related condition may indicate that the clutch 12 is engaging too quickly. As previously described, this situation may occur responsive to a power failure of a battery powered brake or of the motor 16 when being actuated to maintain the clutch 12 in the disengaged configuration. The switch controller 74 may thus be configured to infer a malfunction, such as a power failure, responsive to a rotation of the rod 18 in the engagement direction being greater than a threshold rotational speed.

[0054] The amount of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction may be proportional to the speed of rotation of the rod 18 in the engagement direction. The switch controller 74 may thus be configured to determine whether the rotation of the rod 18 in the engagement direction is greater than a threshold rotational speed by determining whether a magnitude of back EMF voltage generated by the motor 16, such as indicated by a voltage sensor described above, is greater than a threshold magnitude. Responsive to determining that the magnitude of the back EMF voltage is greater than a threshold magnitude voltage, the switch controller 74 may be configured to determine that the rotation of the rod 18 in the engagement direction satisfies a predefined condition.

[0055] The switch controller 74 may also be configured to determine whether a speed of the rotation of the rod 18 in the engagement direction is greater than a threshold rotational speed based on the linear position sensor 80 proximate the rod 18. As previously described, the linear position sensor 80 may be configured to monitor and indicate a linear position of a tag 82 proximate the linear position sensor 80 along the rotational axis of the rod 18. The tag 82 may be linearly moveable along the length of the rod 18 with the rotation of the rod 18 in the engagement direction. The linear position sensor 80 may indicate a linear speed of the tag 82 during the rotation of the rod 18 in the engagement direction by indicating a linear position of the tag 82 on the rotational axis of the rod 18 over time. Because the linear speed of the tag 82 when the rod 18 rotates in the engagement direction may be proportional to the speed at which the rod 18 rotates in the engagement direction, the switch controller 74 may be configured to determine whether the rotation of the rod 18 in the engagement direction is greater than a threshold rotational speed by determining whether the linear speed of the tag 82, as indicated by the linear position sensor 80, is greater 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 18 in the engagement direction satisfies a predefined condition.

[0056] The switch controller 74 may further be configured to determine whether a speed of the rotation of the rod 18 in the engagement direction is greater than a threshold rotational speed based on the rotation sensor 84. As previously described, the rotation sensor 84 may be positioned proximate a sensor ring 86 coupled to and rotatable with the rod 18 when the rod 18 rotates in the engagement direction, and may be configured to indicate a rotational speed of the sensor ring 86 during the rotation of the rod 18 in the engagement direction.

[0057] Specifically, as rotation of the rod 18 causes rotation of the sensor ring 86, the rotation sensor 84 may detect rotational movement of the sensor ring 86 by detecting each occurrence of a tag 88 passing by the rotation sensor 84. The rotation sensor 84 may thus indicate a rotational speed of the sensor ring 86 by indicating the number of detected rotational movements of the sensor ring 86 over time, or more particularly, by indicating the number of tags 88 detected to move past the rotation sensor 84 over time. Because the rotational speed of the sensor ring 86 may be proportional to the rotational speed of the rod 18 during the rotation of the rod 18 in the engagement direction, the switch controller 74 may be configured to determine whether the rotation of the rod 18 in the engagement direction is greater than a threshold rotational speed by determining whether the rotational speed of the sensor ring 86 is greater than a threshold rotational speed. Responsive to determining that the rotational speed of the sensor ring 86 indicated by the rotation sensor 84 is greater than a threshold rotational speed, the switch controller 74 may be configured to determine that rotation of the rod 18 in the engagement direction satisfies a predefined condition.

[0058] When determining whether a rotation of the rod 18 in the engagement direction satisfies a predefined condition, the switch controller 74 may or may not be configured to explicitly determine whether the rod 18 is rotating in the engagement direction, as described above. For instance, the system 10 may be configured such that rotation of the rod 18 in the engagement direction can be inferred from the existence of the satisfied predefined condition. For example, the rod 18 may primarily rotate at a speed greater than a threshold speed responsive to a rotation of the rod 18 in the engagement direction during a malfunction, such as a power failure of a battery powered brake. [0059] The predefined condition monitored for by the switch controller 74 may also include 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 the engagement direction. As discussed above, the actuator 64 may be configured to only apply the brake 62 to the rod 18 when the polarity of the voltage across the motor 16 matches the expected polarity of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction. The predefined condition may thus be irrespective of the rotation of the rod 18. As an example, responsive to a battery powered brake of the system 10 malfunctioning, such as due to a power failure, the battery powered brake may generate and communicate a fault code to the switch controller 74. For instance, the fault code may be generated by the power controller 21, motor 16, or electromagnetic brake 60. The predefined condition may thus include a fault code notification from a battery powered brake. Responsive to such a fault code, the switch controller 74 may be configured do determine that the predefined condition is satisfied, and transition the switch 76 to a closed state.

[0060] FIG. 5 illustrates a process 100 for controlling a clutch of a vehicle. The process

100 may be performed by the system 10, such as by the power controller 21 and the switch controller 74, to control the clutch 12 of the vehicle 14.

[0061] In block 102, the clutch 12 may be transitioned to the disengaged configuration. In particular, the power controller 21 may actuate the motor 16 to rotate the rod 18 in the disengagement direction. Rotating the rod 18 in the disengagement direction may cause the clutch 12 to transition from the engaged configuration to the disengaged configuration, as described above.

[0062] In block 104, the clutch 12 may begin transitioning from the disengaged configuration back to the engaged configuration. Specifically, responsive to the clutch 12 being placed in the disengaged configuration, the power controller 21 may actuate the motor 16 to continue applying torque to the rod 18 in the disengagement direction and thereby maintain the clutch 12 in the disengaged configuration. Thereafter, the motor 16 may cease providing such maintaining torque, and the bias of the clutch 12 may begin transitioning the clutch 12 back to the engaged configuration. The power controller 21 may purposefully cause the motor 16 to cease providing the maintaining torque to transition the clutch 12 from the disengaged to the engaged configuration. Alternatively, a power failure associated with the motor 16 may occur, such as due to a malfunction of the motor 16, power controller 21, battery 20, or wiring therebetween, which may cause the motor 16 to unexpectedly cease providing the maintaining torque on the rod 18. [0063] In block 106, a determination may be made, such as by the switch controller 74, of whether a predefined condition is satisfied. The predefined condition may include one or more of the exemplary predefined conditions described above. For instance, the predefined condition may include the rod 18 rotating in the engagement direction, as caused by the transition of the clutch 12 from the disengaged to the engaged configuration. In addition or alternatively, the predefined condition may include rotation of the rod 18 in the engagement direction satisfying a predefined condition, such as the rotational speed of the rod 18 being greater than a threshold rotational speed. [0064] For example, determining whether the rotation of the rod 18 in the engagement direction satisfies a predefined condition may include tracking linear movement of the tag 82 over time using the linear position sensor 80, such as during the rotation of the rod 18 in the engagement direction. Thereafter, a linear speed of the tag 82 may be calculated based on the tracked linear movement over time, and a determination may be made of whether the calculated tag speed is greater than a threshold tag speed. If so, then a determination may be made that the rotation of the rod 18 in the engagement direction satisfies the predefined condition (“Yes” branch of block 106). [0065] As a further example, determining whether the rotation of the rod 18 in the engagement direction satisfies a predefined condition may include tracking rotational movement of the sensor ring 86 over time using the rotation sensor 84, such as during the rotation of the rod 18 in the engagement direction. A rotational speed of the sensor ring 86 may then be calculated based on the tracked rotational movement of the sensor ring 86 over time. A determination may be made of whether the rotational speed of the sensor ring 86 is greater than a threshold rotational speed. If so, then a determination may be made that the rotation of the rod 18 in the engagement direction satisfies the predefined condition (“Yes” branch of block 106).

[0066] Monitoring for occurrence of the predefined condition may continue throughout the transition of the clutch 12 to the engaged configuration. Responsive to not detecting the predefined condition during the transition of the clutch 12 from the disengaged to the engaged configuration (“No” branch of block 106), the process 100 may return to block 102 in which the clutch 12 is again transitioned to the disengaged configuration. Responsive to detecting occurrence of the predefined 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 74 may be configured to enable the actuator 64 to apply the brake 62 to the rod 18 using the back EMF 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.

[0067] In block 110, the brake 62 may be adjusted, such as by the actuator 64, during the remainder of the transition of the clutch 12 from the disengaged configuration to the engaged configuration 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 be proportional to the rotational speed of the rod 18 in the engagement direction, which may be proportional to the amount or magnitude of back EMF voltage generated by the motor 16 from the rotation of the rod 18 in the engagement direction. As the brake 62 applies resistive force to the rod 18 that slows rotation of the rod 18 in the engagement direction, which in turn slows the speed of the transition of the clutch 12 to the engaged configuration, the motor 16 may generate less back EMF voltage. Consequently, the actuator 64 may decrease the resistive force applied by the brake 62 to the rod 18 based on the decreased back EMF voltage, such as to prevent the clutch 12 transition from becoming excessively slow. As the rotational speed of the rod 18 thereafter increases from the decreased resistive force applied by the brake 62, the motor 16 may generate increased back EMF voltage, which may cause the actuator 64 to increase the resistive force applied by the brake 62 to the rod 18. Hence, the actuator 64 may be configured to perform cycles of reducing and increasing the resistive force applied to the rod 18 by the brake 62 as a function of the rotational speed of the rod 18 to maintain the rotation of rod 18 and, correspondingly, the transition of the clutch 12, near a desired speed.

[0068] Upon the clutch 12 being fully transitioned to the engaged configuration, the rod

18 may cease to rotate in the engagement direction. Although the clutch 12 when in the engaged configuration may apply a force on the rod 18 in the engagement direction, this force may not be enough to overcome the releasable lock formed between the pin 34 and detent 36 when the clutch 12 transitions to the engaged configuration. Consequently, the rod 18 may cease rotating in the engagement direction, and the motor 16 may stop generating the back EMF voltage that causes the actuator 64 to apply the brake 62 to the rod 18. Correspondingly, the brake 62 and actuator 64 may return to a position in which the brake 62 is no longer providing a substantial resistive force to the rod 18. When the actuator 64 is a solenoid actuator, for example, the spring 70 may cause the piston 68 to move towards the rod 18 and thereby loosen the brake 62 around the rod 18. [0069] In block 112, a determination may be made, such as by the switch controller 74, of whether the clutch 12 has fully transitioned to the engaged configuration, or has again begun transitioning to the disengaged configuration (block 102), which may occur before the clutch 12 is fully transitioned to the engaged configuration. The switch controller 74 may be configured to make this determination based on sensor data, such as that described above, indicating that the rotation of the rod 18 has stopped or changed direction. Responsive to determining that the clutch 12 has fully transitioned to the engaged configuration, or is again transitioning to the disengaged configuration (“Yes” branch of block 112), in block 114, the back EMF braking system 61 may be disabled. For example, the switch controller 74 may be configured to disable the back EMF braking system 61 by placing the switch 76 back in the open position.

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

[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 (block 106) after the clutch begins to transition to the engaged configuration (block 104), the switch controller 74 may be configured to begin monitoring for and detect predefined conditions upon initiation of the system 10. For example and as described above, the monitored predefined condition 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 configured to only apply the brake 62 when the rod 18 rotates in the engagement direction, the switch controller 74 may thus be configured to detect a predefined condition, and to responsively enable the actuator 64 to apply the brake 62 to the rod 18, prior to the clutch 12 transitioning to the engaged configuration.

[0072] As described above, uncontrolled transitions of an electric clutch may cause vehicle damage, 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 configuration to an engaged configuration, a vehicle may include a brake operatively coupled to the clutch. The brake may be powered by back EMF voltage generated by the transition of the clutch from the disengaged configuration to the engaged configuration, and may be configured to resist transition of the clutch to the engaged configuration in proportion to the speed at which the clutch transitions to the engaged configuration. The brake may thus provide a controlled transition of the clutch that is resistant to battery-related power failures.

[0073] In general, the routines executed to implement the embodiments of the invention, whether implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions, or even a subset thereof, may be referred to herein as "computer program code," or simply "program code." Program code typically comprises computer readable instructions that are resident at various times in various memory and storage devices 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 elements embodying the various aspects of the embodiments of the invention. Computer readable program instructions 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 more programming languages.

[0074] Various program code described herein may be identified based upon the application within that it is implemented in specific embodiments of the invention. However, it should be appreciated that any particular program nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature. Furthermore, given the generally endless number of 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 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 the embodiments of the invention are not limited to the specific organization and allocation of program functionality described herein.

[0075] The program code embodied in any of the applications/modules described herein is capable of being individually or collectively distributed as a program product in a variety of different forms. In particular, the program code may be distributed using a computer readable storage medium having computer readable program instructions thereon for causing a processor to carry out aspects of the embodiments of the invention.

[0076] Computer readable storage media, which is inherently non-transitory, may include volatile and non-volatile, and removable and non-removable tangible media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Computer readable storage media may further include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid state memory technology, 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 any other medium that can be used to store the desired information and which can be read by a computer. A computer readable storage medium should not be construed as transitory signals per se (e.g., radio waves or other propagating electromagnetic waves, electromagnetic waves propagating through a transmission media such as a waveguide, or electrical signals transmitted through a wire). Computer readable program instructions may be downloaded to a computer, another type of programmable data processing apparatus, or another device from a computer readable storage medium or to an external computer or external storage device via a network. [0077] Computer readable program instructions stored in a computer readable medium may be used to direct a computer, other types of programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions that implement the functions, acts, and/or operations specified in the flowcharts, sequence diagrams, and/or block diagrams. 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 apparatus to produce a machine, such that the instructions, which execute via the one or more processors, cause a series of computations to be performed to implement the functions, acts, and/or operations specified in the flowcharts, sequence diagrams, and/or block diagrams.

[0078] In certain alternative embodiments, the functions, acts, and/or operations specified in 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 of the flowcharts, sequence diagrams, and/or block diagrams may include more or fewer blocks than those illustrated consistent with embodiments of the invention.

[0079] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the invention. As used herein, 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 stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Furthermore, to the extent that the terms “includes”, “having”, “has”, “with”, “comprised of’, or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0080] While all of the invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. 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.

Claims

What is claimed is:

1. A method for controlling a clutch of a vehicle using a system comprising an electric motor, a rod coupled to and rotatable with the electric motor in a first direction when the electric motor is actuated for transitioning the clutch from an engaged configuration to a disengaged configuration, and a brake coupled to the rod, the method comprising the steps of: actuating the motor and rotating the rod in the first direction to transition the clutch from the engaged configuration to the disengaged configuration; initiating a transition of the clutch from the disengaged configuration to the engaged configuration; rotating the rod in a second direction opposite the first direction responsive to initiating the transition of the clutch from the disengaged configuration to the engaged configuration; and applying the brake to the rod using back EMF voltage generated by the motor from the rotation of the rod in the second direction.

2. The method of claim 1, further comprising: monitoring for a predefined condition; and enabling application of the brake to the rod responsive to the predefined condition.

3. The method of claims 1 or 2, further comprising: determining whether the rod is rotating in the second direction; and applying the brake to the rod responsive to determining that the rod is rotating in the second direction.

4. The method of any one of claims 1-3, further comprising: determining whether the rotation of the rod in the second direction satisfies a predefined condition; and enabling application of the brake to the rod responsive to determining 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 powered brake, and determining whether the rotation of the rod in the second direction satisfies a predefined condition comprises determining whether a power failure of the battery powered brake has occurred.

6. The method of claims 4 or 5, wherein determining whether the rotation of the rod in 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 determining whether the rotation of the rod in the second direction satisfies a predefined condition comprises determining whether a magnitude 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 tag operatively coupled to and linearly moveable along a rotational axis of the rod with the rotation of the rod in the second direction and a linear position sensor proximate the rod that indicates a linear position of the tag on the rotational axis of the rod during the rotation of the rod in the second direction, and determining whether the rotation of the rod in the second direction satisfies a predefined condition comprises: tracking linear movement of the tag over time using the linear position sensor during the rotation of the rod in the second direction; calculating a tag speed based on the tracked linear movement of the tag over time; and determining 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 sensor ring coupled to and rotatable with the rotation of the rod in the second direction and a rotation sensor proximate the sensor ring that indicates rotational movement of the sensor ring, and determining 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 sensor during the rotation of the rod in the second direction; calculating a rotational speed of the sensor ring based on the tracked rotational movement of 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 an actuator coupled to the brake, and applying the brake to the rod using the back EMF voltage generated 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 rotation of 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 EMF voltage generated by the motor from the rotation of the rod in the second direction comprises applying a second force on the rod by the brake that is greater than the first force and resists rotation of 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 flexible material forming 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 using the back EMF voltage generated by the motor from the rotation of the rod in the second direction comprises: applying a first force on the rod by the brake based on the back EMF voltage that resists rotation 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 actuated for 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 opposite the first direction caused by a transition of the clutch from the disengaged configuration to the engaged 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. The system of claim 14, further comprising: a sensor indicating a predefined condition; and a controller coupled to the sensor, actuator, and motor, the controller configured to enable the actuator to apply the brake using the back EMF voltage responsive to the predefined condition based on the sensor.

16. The system of claims 14 or 15, 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 configured to enable the actuator to apply the brake using the back EMF voltage responsive to determining that the rod is rotating in the second direction based on the sensor.

17. The system of any one of claims 14-16, further comprising: a sensor indicating whether the rotation of the rod in the second direction satisfies a predefined condition; and a controller coupled to the sensor, actuator, and motor, the controller configured to enable the actuator to apply the brake using the back EMF voltage responsive to determining that the rotation of the rod in the second direction satisfies the predefined condition based on the sensor.

18. The system of claim 17, further comprising a battery powered brake coupled to the rod, wherein the predefined condition satisfied by the rotation of the in the second direction comprises a power failure of the battery powered brake.

19. The system of claims 17 or 18, wherein the predefined condition satisfied by the rotation of the rod in the second direction comprises a speed of the rotation of the rod in the second direction being greater than a threshold rotational speed.

20. The system of any one of claims 17-19, wherein the predefined condition satisfied by the rotation of the rod in the second direction comprises a magnitude of the back EMF voltage generated by the motor from the rotation of the rod in the second direction being greater than a threshold magnitude.

21. The system of any one of claims 17-20, further comprising: a tag operatively coupled to and linearly moveable along a rotational axis of the rod with the rotation of the rod in the second direction; and a linear position sensor proximate the rod that indicates a linear speed of the tag during the rotation of the rod in the second direction, wherein the predefined condition satisfied by the rotation of the rod in the second direction comprises the linear speed of the tag indicated by the linear position sensor being greater than a threshold linear speed.

22. The system of any one of claims 17-21, further comprising: a sensor ring coupled to and rotatable with the rotation of the rod in the second direction; and a rotation sensor proximate the sensor ring that indicates a rotational speed of the sensor ring during the rotation of the rod in the second direction, wherein the predefined condition satisfied by the rotation of the rod in the second direction comprises the rotational speed of the sensor ring indicated by the rotation sensor being greater than a threshold rotational speed.

23. The system of any one of claims 14-22, wherein the actuator comprises a solenoid actuator 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 on the brake responsive to receiving the back EMF voltage from the motor, and the brake amplifies the 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 of flexible 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.