Abstract:
A control system for a transmission includes a transmission control module having a processor configured to determine an output torque command and having a pulse width modulation (PWM) switch configured to generate a PWM signal at least partially representative of the output torque command. A network is in communication with the transmission control module and is configured to receive and transmit the PWM signal. A driver is integrated with the electromagnetic actuator and is in communication with the network. The driver is configured to receive the PWM signal and convert the PWM signal into a drive current that enables the electromagnetic actuator to fulfill the output torque command.

Description:
FIELD 
       [0001]    The present disclosure relates to a control system for a transmission having remote drivers, and more particularly to a control system having an integrated motor driver for electromechanical gear and clutch actuation in a transmission. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art. 
         [0003]    Automatic and manual transmissions in motor vehicles employ an electronic control module to control the operation of the transmission. The electronic control module receives electronic inputs from various sensors on the vehicle and processes that information to determine the vehicle&#39;s operating conditions. Depending on these operating conditions the electronic control module controls transmission upshifts and downshifts, transmission shift feel, and starting device apply and release timing. Electronic control of these transmission operating characteristics provides for consistent and precise shift points and shift quality based on the operating conditions of the vehicle. 
         [0004]    Depending on the transmission architecture, the electronic module may actuate multiple electromagnetic actuators. Accordingly, for any given transmission architecture, the electronic control module must specific to that architecture and have the appropriate motor or electromagnetic drivers to properly drive the electromagnetic actuators. While these systems have proven effective, there is room in the art for an electronic control system that decentralizes the driver control of the electromagnetic actuators which may enable the re-use of the same electronic control module across various transmission architectures. 
       SUMMARY 
       [0005]    A control system for a transmission in a motor vehicle is provided. The control system is operable to control an electromagnetic actuator in a transmission. The system includes a transmission control module having a processor configured to determine an output torque command and having a pulse width modulation (PWM) switch configured to generate a PWM signal at least partially representative of the output torque command. A network is in communication with the transmission control module and is configured to transmit the PWM signal. A driver is integrated with the electromagnetic actuator and is in communication with the network. The driver is configured to receive the PWM signal and convert the PWM signal into a drive current to the appropriate phases that enables the electromagnetic actuator to fulfill the output torque command. 
         [0006]    In one aspect, the system further includes a position sensor integrated with the electromagnetic actuator and in communication with the network, wherein the position sensor is configured to detect a magnitude of rotation of the electromagnetic actuator and to generate a signal, which may be CAN, PWM, analog or another type of signal to the transmission control module at least partially representative of the magnitude of rotation. 
         [0007]    In another aspect, the transmission control module determines the output torque command at least partially based on the PWM signal from the position sensor. 
         [0008]    In yet another aspect, the network is a controller area network bus. 
         [0009]    A transmission is also provided and includes an input shaft, an output shaft, a gearbox coupled to the input shaft and the output shaft, wherein the gearbox includes at least one torque transmitting mechanism selectively engageable to provide one or more speed ratios between the input shaft and the output shaft, and an actuator coupled to the torque transmitting mechanism, wherein the actuator is positioned to selectively engage the torque transmitting mechanism. A motor unit including an electric motor and a driver integrated into the electric motor includes a rotor coupled to the actuator, wherein an output torque applied to the rotor by the electric motor positions the actuator. The transmission also includes a transmission control module having a processor configured to determine an output torque command and having a pulse width modulation (PWM) switch configured to generate a PWM signal at least partially representative of the output torque command and a network in communication with the transmission control module and the driver of the motor unit. The motor driver is configured to receive the PWM signal and convert the PWM signal into drive currents corresponding to the different phases of the motor windings that enables the electric motor to provide the commanded output torque to the rotor to position the actuator. 
         [0010]    Further aspects, advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWING 
         [0011]    The drawing described herein is for illustration purposes only and is not intended to limit the scope of the present disclosure in any way. 
           [0012]    The drawing is a schematic view of a powertrain of a motor vehicle according to the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
         [0014]    With reference to the drawing, an exemplary powertrain for a motor vehicle is generally indicated by reference number  10 . The powertrain  10  includes an engine  12  for providing power and torque to propel the motor vehicle. The engine  12  may be a conventional internal combustion engine or an electric motor, or any other type of prime mover, without departing from the scope of the present disclosure. The engine  12  is configured to provide driving torque to a launch or starting device  14  through an engine output shaft  16 . The engine output shaft  16  may be connected to the starting device  14  through a flexplate (not shown) or other connecting device. The starting device  14  may be a hydrodynamic device, such as a fluid coupling or torque converter, an electric motor, or a friction device such as a dry or wet launch clutch or dual clutch. It should be appreciated that any type of starting device  14  may be employed without departing from the scope of the present disclosure. 
         [0015]    The starting device  14  transfers drive torque to an automatic transmission  20 . The transmission  20  may be a front wheel drive transmission or a rear wheel drive transmission. Generally speaking, the transmission  20  includes a transmission input shaft  22  and a transmission output shaft  24 . The transmission input shaft  22  is functionally interconnected with the engine  12  via the starting device  14  and receives input torque or power from the engine  12 . Accordingly, the transmission input shaft  22  may be a turbine shaft in the case where the starting device  14  is a hydrodynamic device, dual input shafts where the starting device  14  is dual clutch, or a drive shaft where the starting device  14  is an electric motor. Disposed between the transmission input shaft  22  and the transmission output shaft  24  is a gear and clutch arrangement  25 . The gear and clutch arrangement  25  may include a plurality of gear sets, a plurality of clutches and/or brakes, a plurality of synchronizers, and/or a plurality of shafts. The plurality of gear sets may include individual intermeshing gears, such as planetary gear sets or co-planar gear sets, that are connected to or selectively connectable to the plurality of shafts through the selective actuation of the plurality of clutches/brakes or synchronizers. The plurality of shafts may include layshafts or countershafts, sleeve and center shafts, reverse or idle shafts, or combinations thereof. The clutches/brakes and synchronizers are selectively engageable to initiate at least one of a plurality of gear or speed ratios by selectively coupling individual gears within the plurality of gear sets to the plurality of shafts. It should be appreciated that the specific arrangement and number of the gear sets, clutches/brakes, and shafts within the transmission  20  may vary without departing from the scope of the present disclosure. For purposes of example, the transmission  20  is illustrated as a layshaft transmission having three synchronizer assemblies  26 A,  26 B, and  26 C and a single launch clutch  14 . However, as discussed above, the transmission  20  may take various forms without departing from the scope of the present invention. 
         [0016]    The transmission output shaft  22  is preferably connected with a final drive unit  27 . The final drive unit  26  may include, for example, propshafts, differential assemblies, drive axles and wheels. 
         [0017]    The transmission  20  also includes a transmission control module  28 . The transmission control module  28  is preferably an electronic control device having a preprogrammed digital computer or processor, control logic, memory used to store data, and at least one I/O peripheral such as a pulse width modulation switch. The control logic includes a plurality of logic routines for monitoring, manipulating, and generating data. The transmission control module  28  is in electronic communication with a first motor unit  30  and a second motor unit  32 . It should be appreciated that the transmission control module  28  may be in electronic communication with any number of motor units without departing from the scope of the present invention. 
         [0018]    The first motor unit  30  includes an electric motor  34  with an integrated electronics package  36 . The electric motor  34  is preferably a brushless DC motor. However, the electric motor  34  may also be any electromagnetic machine such as, for example, a brushed motor or a stepper motor. The integrated electronics package  36  includes a motor driver circuit  36 A that provides an interface between signal processing circuitry, i.e. the controller  28 , and the electric motor  34  and is used to drive the electric motor  34  based on command signals from the controller  28 . These command signals are represented by the solid line  38  shown in the drawing and are preferably pulse-width modulated signals communicated via a computer aided network. The integrated electronics package  36  also includes a position sensor  36 B for sensing a position of a rotor  40  of the electric motor  30 . The position sensor  36 B communicates position feedback to the controller  28  via a controller area network (CAN) bus, represented by the dashed line  42  shown in the drawing. Alternatively, the position sensor  36 B may be a separate electronics package from the electronics package  36 . The rotor  40  of the first motor unit  30  is coupled to an actuator  44  for engaging the starting device  14 . 
         [0019]    The second motor unit  32  includes an electric motor  50  with an integrated electronics package  52 . The electric motor  50  is preferably a brushless DC motor. However, the electric motor  50  may also be any electromagnetic machine such as, for example, a brushed motor or a stepper motor. The integrated electronics package  52  includes a motor driver circuit  52 A that provides an interface between signal processing circuitry, i.e. the controller  28 , and the electric motor  50  and is used to drive the electric motor  50  based on command signals from the controller  28 . These command signals are represented by the solid line  54  shown in the drawing and are preferably pulse-width modulated signals communicated via controller area network (CAN) or other electrical wiring. The integrated electronics package  52  also includes a position sensor  52 B for sensing a position of a rotor  56  of the electric motor  50 . The position sensor  52 B communicates position feedback to the controller  28  via a computer aided network, represented by the dashed line  58  shown in the drawing. Alternatively, the position sensor  52 B may be a separate electronics package from the electronics package  52 . The rotor  56  of the second motor unit  32  is coupled to a gear  60  that drives a barrel cam  62 . The barrel cam  62  is configured to engage the plurality of synchronizers  26 A-C. 
         [0020]    During operation of the powertrain  10 , the position sensor  36 B sends real-time position data of the rotor  40  to the controller  28 . The controller  28  receives the real-time position data and performs closed-loop control calculations to determine a required torque command to the first motor unit  30 . The torque command is converted by the controller  28  into a pulse width modulated (PWM) signal and communicated to the motor driver  36 A. The motor driver  36 A receives the PWM signal and based on the PWM signal commands an appropriate current to the electric motor  34  in order to produce the required torque. The second motor unit  32  operates in a substantially similar manner as the first motor unit  30 . 
         [0021]    The integration of the entire motor driver inside a single motor unit generally provides the highest level of functionality at the lowest cost and physical size. This further allows using existing transmission control modules to control multiple types of transmissions, including dual clutch transmissions, manual transmissions, or planetary gear transmissions. 
         [0022]    The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.