Patent Publication Number: US-2021179070-A1

Title: Powertrain controls for an electric motor and an automated manual transmission

Description:
BACKGROUND 
     The present application relates generally to powertrain controls for an electric motor and an automated manual transmission (“AMT”) and related apparatuses, methods, systems, and techniques. Current approaches to powertrain controls in such powertrains suffer from a number of shortcomings and unmet needs. There remains a substantial need for the unique apparatuses, methods, systems, and techniques disclosed herein. 
     DISCLOSURE OF ILLUSTRATIVE EMBODIMENTS 
     For the purposes of clearly, concisely and exactly describing illustrative embodiments of the present disclosure, the manner, and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain example embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created and that the invention includes and protects such alterations, modifications, and further applications of the example embodiments as would occur to one skilled in the art. 
     SUMMARY 
     Example embodiments include unique apparatus, methods, systems and techniques for powertrain controls for powertrains including an electric motor and an AMT. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating certain aspects of an example vehicle system. 
         FIG. 2  is a schematic diagram illustrating certain aspects of an example shift event process. 
         FIG. 3  is a schematic diagram illustrating certain aspects of example supervisory control logic. 
         FIG. 4  is a schematic diagram illustrating certain aspects of an example low voltage wiring harness. 
         FIG. 5  is a graph illustrating variation in a torque command and 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , there is illustrated a schematic view of an example vehicle system  100 . In the illustrated embodiment, vehicle system  100  includes a powertrain comprising a transmission  124 , an electric motor  126 , an energy storage system (“ESS”)  127 , and power electronics  129 . Electric motor  126  is operatively coupled with transmission  124  and with power electronics  129  which are, in turn, operatively coupled with ESS  127 . Transmission  124  is operatively coupled with a differential  154  which, in turn, is operatively coupled with ground engaging members  152  (e.g., wheels) such that positive torque may be provided from motor  126  via transmission  124  to ground-contacting members  152  and negative torque may be provided from ground-contacting members  152  to motor  126  via transmission  124 . The powertrain may also include additional components that are not illustrated such as an engine, one or more clutches, torque converters, or other powertrain components. Vehicle system  100  may be provided in a number of vehicles including, for example, a semi tractor-trailer, bus, delivery truck, service truck, construction machine, or off-road vehicle to name a few examples. 
     In the illustrated embodiment, the powertrain of vehicle system  100  is in the form of an electric vehicle in which motor  126  can provide torque for vehicle propulsion, ESS  127  is in the form of a high voltage battery, and power electronics  129  are in the form of a DC link and inverter operatively coupled with motor  126  and ESS  127 . Electric motor  126  can be controlled to operate as a motor powered by energy from ESS  127  or as a generator providing power to ESS  127 . When motor  126  is controlled to operate as a motor, the inverter of power electronics  129  is operated to convert DC power from ESS  127  to AC power to drive motor  126 . When motor  126  is controlled to operate as a generator, it provides AC power to the inverter of power electronics  129  which is operated to convert the AC power to DC power to charge ESS  127 . In other operating modes, motor  126  may be passive such that it is not providing positive or negative torque. In the depicted form, motor  126  has a common rotor and a common stator and provided as an integrated single unit. In other embodiments, a completely or partially separate motor, generator, rotor, stator, or the like may be integrated with engine  122  or transmission  124 . Furthermore, it should be appreciated that in alternative embodiments some of the illustrated features may be absent and/or other optional devices and subsystems may be included (not shown). 
     In other embodiments, the powertrain of vehicle system  100  may include an internal combustion engine. In some forms, the powertrain may be configured as a fuel-cell electric vehicle system including a fuel cell system configured to supply power to ESS  127 . In some forms, the powertrain may be configured as a range-extended electric vehicle system including an engine configured to drive a generator to provide electric power to motor  126 . In some forms, the powertrain may be configured as a parallel hybrid powertrain system in which either or both of an engine and motor  126  can provide torque to a driveline for vehicle propulsion. In such embodiments, the engine may be provided as a four-stroke, compression ignition (CI) type with multiple cylinders and corresponding reciprocating pistons coupled to a crankshaft which is coupled to a flywheel that is coupled to a controllable clutch. In other embodiments, the engine may be of a different type, including different fueling, different operating cycle(s), different ignition, or the like. The engine may be provided with a number of related components which are not illustrated including an aftertreatment system, a mechanical accessory drive, an electrical accessory drive, and an air handling system, which may include one or more intake manifolds, exhaust manifolds, turbochargers, superchargers, air filters or other intake air and exhaust system components. 
     In the illustrated embodiment, ESS  127  is provided in the form of a high-voltage battery system. Other embodiments may include other types of battery systems or other power storage devices such as super-capacitors or ultra-capacitors. Furthermore, power electronics  129  are provided in a form comprising an AC/DC converter such as an inverter and a DC link which are configured to selectably convert DC power from ESS  127  to AC power to drive motor  126  and to convert AC power from motor  126  to DC power to change ESS  127 . 
     Vehicle system  100  further includes an electronic control system (ECS) comprising a plurality of control modules including gear shift control module (GSCM)  132 , transmission control module (TCM)  134 , motor control module (MCM)  136 , and supervisory control module (SCM). The ECS may also include additional control modules that are not illustrated such as an engine control module (ECM) or other control modules. It shall be appreciated that the GSCM  132 , TCM  134 , MCM  136 , and SCM  138  and other control modules of the ECS may also be referred to as control units or controllers in some applications and may be provided in self-contained housings. The GSCM  132 , TCM  134 , MCM  136 , and SCM  138  and other control modules of the ECS may be provided in the form of microprocessor-based or microcontroller-based circuitry which are configured to execute operating logic to perform the acts, methods, processes, and techniques disclosed herein as well as various control, management, and/or regulation functions. The operating logic may be provided in the form of program instructions stored in a non-transitory memory medium, dedicated hardware such as a hardwired state machine, analog calculating machines, or combinations thereof. 
     In the illustrated embodiment, GSCM  132 , TCM  134 , MCM  136 , and SCM  138  are implemented in physically separate devices or units that are in operative communication with one another. In certain embodiments, the SCM  138  and the MCM  136  may be implemented in the same physical device. It shall be appreciated that the supervisory control disclosed herein may be provided and implemented as controls internal to the MCM  136  (for example, in embodiments where the SCM  138  and the MCM  136  are provided in the same physical device or unit), or in a physically separate device (for example, in embodiments where the SCM  138  and the MCM  136  are provided as a physically separate devices or units). The control modules of the ECS may include one or more signal conditioners, modulators, demodulators, Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), limiters, oscillators, control clocks, amplifiers, signal conditioners, filters, format converters, communication ports, clamps, delay devices, memory devices, Analog to Digital (A/D) converters, Digital to Analog (D/A) converters, and/or different circuitry or electrical components. 
     The ECS of vehicle system  100  includes a vehicle controller area network (“CAN”)  194  which may be an unrestricted or public J1939-based network of the type typically provided by a vehicle OEM as a part of the vehicle system  100 . Vehicle CAN  194  provides operative communication between a plurality of controllers of vehicle system  100  including GSCM  132 , TCM  134 , and SCM  138 . It shall be appreciated that vehicle CAN  194  may also provide operative communication between additional controllers of vehicle system  100 . 
     The ECS of vehicle system  100  further includes a low voltage wiring harness  191  including a service CAN  192 , a powertrain CAN  196  and a private CAN  198  which provide plurality of communication networks of the low-voltage wiring harness  191 . Service CAN  192  provides operative communication with SCM  138  and an external service tool (not illustrated). Powertrain CAN  196  provides operative communication between TCM  134  and SCM  138 . Private CAN  198  provides operative communication between SCM  138  and MCM  136 . Service CAN  192 , a powertrain CAN  196  and a private CAN  198  may be configured to operate under the J1939 protocol as well as various other communication protocols. 
     In the illustrated embodiment, transmission  124  is provided as an automated manual transmission (“AMT”) which can operate in a drive mode and a manual mode. It shall be appreciated that AMT transmissions are distinct from automatic transmissions in that they include a gearbox and clutch more similar to a gearbox and clutch found in a manual transmission, but are also distinct from a manual transmission in that the clutch of an AMT is electronically controllable allowing automatic execution of gear shifts and eliminating the need for a clutch pedal. In the drive mode, the AMT undergoes shift events in an automated manner in response to acceleration commands from an accelerator pedal and/or cruise control system. In the manual mode, the AMT undergoes shift events in response to operator manipulation of or input to operator controls such as shift lever  142  which is operatively associated with GSCM  132 . The illustrated components permit the ECS of vehicle system  100  to successfully complete a shift event by interfacing SCM  138  with TCM  134  and MCM  136  and facilitating communication between these components using J1939 CAN messages, it being appreciated that other embodiments may facilitate communication between these components using other messaging protocols. In order to complete a shift event, SCM  138  establishes supervisory control over electric motor power (torque and speed) whilst arbitrating between driver requests, transmission controller requests, operating conditions and other power-train control requests along with the present and estimated future operating conditions of the powertrain of the vehicle system  100 . 
     The SCM  138  provides supervisory control over the operation of MCM  136  and motor  126  during a gear shift event. The supervisory control over the operation of MCM  136  may include the SCM  138  suspending a non-shifting response of the MCM  136  to an operator torque request such as a request generated in response to an accelerator pedal position or a cruise control setting. It shall be appreciated that the operator torque request and other types of torque requests described herein may include a requested motor torque and a requested motor speed. The normal or non-shifting response of the MCM  136  to an operator torque request may include the MCM  136  receiving the operator torque request and controlling the motor to operate to provide the torque indicated by the operator torque request. The normal or non-shifting response of the MCM  136  may be implemented in and provided by conventional control components residing in the MCM  136  and/or another control module that are responsive to operator torque requests received via one of the CAN networks of the vehicle system  100 . 
     The supervisory control may further include the SCM  138  arbitrating between a plurality of motor operation requests received over the one or more controller area networks (including the operator torque request) to select a winning motor operation request. Each of the plurality of motor operation requests includes at least one parameter indicating a requested operation of the motor  126 . The motor operation requests may be specified in terms of a number of operational parameters of the motor  126  including requests for motor torque, motor speed, motor power, motor current, motor voltage, or combinations thereof. In certain forms, one or more of the plurality of motor operation requests may include a requested motor torque. In certain forms, one or more of the plurality of motor operation requests may include a requested motor speed. In certain forms, one or more of the plurality of motor operation requests may include a requested motor torque and a requested motor speed. In certain forms, one or more of the plurality of motor operation requests may include a requested motor current. In certain forms, one or more of the plurality of motor operation requests may include a requested motor voltage. In certain forms, one or more of the plurality of motor operation requests may include a requested motor current and a requested motor voltage. The plurality of motor operation requests may include the operator torque request, other operator torque requests (if multiple operator torque requests are present, for example, if an accelerator pedal request is generated during cruise control operation), transmission torque requests from TCM  134 , torque limits determined in response to present operating conditions of the motor  126  and/or ESS  127 . and other power-train control requests along with the present and estimated future operating conditions of the power-train. 
     The SCM  138  may be configured to perform an arbitration by evaluating priority parameters associated with each of the plurality of torque requests according to priority logic. For example, the TCM  126  may be configured to provide a level 1 priority parameter (1-T) if the TCM  126  determines that its requested torque is necessary to avoid critical damage or failure of the transmission  124 , to provide a level 2 priority parameter (2-T) if the TCM  126  determines that its requested torque is necessary to avoid undesirable operation of the transmission  124  which is likely to result in accelerated wear or degradation over time but which is not necessary to avoid the level 1 operating condition of the transmission  126 , and to provide a level 3 priority parameter (3-T) if the TCM  126  determines that its requested torque is desirable but is not necessary to avoid the level 1 or level 2 operating conditions of the transmission  126 . The MCM  136  may be configured to provide a level 1 priority parameter=1-M if the MCM  124  determines that its requested torque is necessary to avoid critical damage or failure of the motor  126  and/or ESS  127 , to provide a level 2 priority parameter (2-M) if the MCM  136  determines that its requested torque is necessary to avoid undesirable operation of the motor  126  and/or ESS  127  which is likely to result in accelerated wear or degradation but is not necessary to avoid the level 1 operating conditions, and to provide a level 3 priority parameter (3-T) if the MCM  136  determines that its requested torque is desirable but not necessary to avoid the level 1 or level 2 operating conditions. The GSM  132  may be configured to provide a level 2 priority parameter (2-G) with its torque request. 
     The SCM  138  may be configured to perform a first selection which selects the highest level of priority parameters present and eliminates the lower level priority parameters from consideration. The SCM  138  may be further configured to perform a second selection from among multiple requests of the same priority level. For example, one of parameter 1-M or 1-T may be given first priority over all level 1 parameters 1-T and the other of parameter 1-M or 1-T may be given second priority over all other level 1 parameters. Alternatively, the SCM  138  may be configured to select an average or a weighted average of the torque request values associated with parameter 1-M and parameter 1-T or to select the lower magnitude of the two values. Similar prioritization may be performed for the other priority levels. The supervisory control may further include the SCM as  138  evaluating one or more shift inhibit conditions, and commanding the MCM  136  to control the motor to provide the winning motor operation request when none of the one or more shift inhibit conditions evaluate true. 
     The SCM may be also be configured to control the transition between the non-shifting response of MCM  136  and the suspension of the non-shifting response. For example, at the start of a shift event, SCM  138  may ramp down the torque of motor  126  to a lower value accommodating shifting from an existing operating torque. SCM  138  then arbitrates between various torque requests to select the winning motor operation request. Next, SCM  138  then controls the motor to match the torque/speed requested by the winning request. SCM  138  then ramps the motor torque back to the original operating or driver demand torque. During ramp-down, torque-speed control, and ramp-up, SCM  138  communicates the current operating mode to other controllers in the system via CAN/J1939. SCM  138  also monitors the system status to inhibit shift events. The shift event shall not occur until the supervisory control module clears the shift inhibit condition. 
     With reference to  FIG. 5 , there is illustrated a graph  500  depicting a plurality of curves  510 ,  520  and  530 . Curve  510  illustrates the variation in magnitude of an electric motor torque command from SCM  138  as a function of time. Curve  520  illustrates the variation in the speed of electric motor  126  in response to variation in the electric motor torque command from SCM  138  as a function of time. Curve  530  indicates illustrates variation in the transmission output speed in response to variation in the speed of electric motor  126 . Curves  510 ,  520  and  530  illustrate a plurality of shift events including shift events  515  and  517  as well as other shift events that are not labeled in the interest of preserving clarity. At the beginning of each shift event, the electric motor torque command from SCM  138  illustrated by curve  510  is ramped down rapidly to a negative or braking torque. In response, the speed of motor  126  ramped down to a value corresponding to a winning motor operation request as indicated by the triangular valleys of curve  520 . At the end of each shift event, the electric motor torque command from SCM  138  illustrated by curve  510  is ramped up to a positive torque value which is effective to restore the pre-shift operation of motor  126  as indicated by curve  520 . In the illustrated embodiment, the electric motor torque command from SCM  138  includes a speed command overshoot indicated by the maximum magnitude of curve  510  during a shift event followed by a restoration of the pre-shift command magnitude. 
     With reference to  FIG. 2 , there is illustrated a schematic diagram depicting certain aspects of an example shift event process  200  which may be initiated by an operator command to a shift lever associated with a transmission. Shift event process  200  may be initiated when GSCM  132  generates a message  221  indicating a gear shift request (e.g., a requested transmission gear). The message  221  may be generated in response to an operator input to shift lever  142  or other vehicle controls. The message  221  is then transmitted to TCM  134  and SCM  138  over vehicle CAN  194 . 
     Shift event process  200  next proceeds to conditional  204 . At conditional  204 , SCM  138  evaluates whether a supervisory transmission mode change inhibit condition (STXI) is true. The STXI may be, for example, a gear shift inhibit request which is generated based upon an evaluation performed by SCM  138 . This evaluation may be based upon multiple criteria. For example, a mode change event may be inhibited if one or more of the following conditions is true: battery state of charge (SOC) is too low (e.g., below a threshold), battery contactors are open, the key switch is off, one or more system faults are active, the service brakes are not active and driver issues command to move out of park, the operator requests direction changes (e.g., forward gear to reverse or vice-versa) when vehicle is not stationary, or look-ahead information indicates that a gear shift should be inhibited. 
     If SCM  138  evaluates that a transmission shift inhibit request is true, it generates a message  228  indicating that mode changes are inhibited and transmits the message  228  to TCM  134  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . It shall be appreciated that the system can be provided with communications controls that are calibratible to provide communication of the message over any or all of the CAN networks with which SCM  138  is in operative communication. This calibratible flexibility may be provided for all of the CAN-based communications described herein. In response to message  226 , TCM  134  inhibits gear shifting and generates and transmits a message  229  to GSCM  132  via vehicle CAN  194  indicating that an operator perceptible indication that the gear shift is inhibited should be provided. In response to this message, the GSCM  132  provides an operator perceptible indication that the gear shift is inhibited, for example, providing an output on a display. 
     If SCM  138  evaluates that a transmission gear shift inhibit request is not true, it generates a message  226  indicating that gear shifts are not inhibited and transmits the message to TCM  134  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . In response to message  226 , at conditional  206 , TCM  134  may also evaluate whether an internal transmission mode change inhibit condition (ITXI). The ITXI may be, for example, a gear shift inhibit request which is generated based upon an evaluation performed by TCM  134  of its own operating conditions indicating the state of the transmission with which it is operatively coupled. This evaluation may be based upon multiple criteria. For example, TCM  134  may inhibit shifting when it has already received or is already executing another a conflicting operation, or when it is experiencing an error condition. 
     If conditional  206  evaluates that the ITXI is true, TCM  134  generates a message  227  and transmits the message  227  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . Message  227  indicates to SCM  138  that TCM  134  is self-inhibited from and SCM may respond to message  227  by returning to and repeating the evaluation of conditional  204  or by terminating the process  200  and awaiting receipt of a new message such as message  221 . 
     If conditional  206  evaluates that the ITXI is false, TCM  134  generates messages  231 ,  231 ,  233  and  234 , and transmits the messages  231 ,  231 ,  233  and  234  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . In the illustrated embodiment, message  231  indicates a requested torque (or a requested torque and a requested and speed) of the motor for execution of the shift event, message  232  indicates whether a shift event is in progress, message  233  indicates a selected gear for the shift event (e.g., a gear to which the transmission intends to shift) , and message  234  indicates the current gear of the transmission. In the illustrated embodiment, messages  231 ,  232 ,  233 , and  234  are separate messages. In other embodiments, the information contained in any two or more, up to and including all of the messages  231 ,  232 ,  233 , and  234  may be combined into a single message. In response, at conditional  208 , SCM  138  evaluates whether the requested torque (or the requested torque and speed) of the motor for execution of the shift event can be provided. This evaluation may be performed by SCM  138  sending a message including a motor torque and speed request to MCM  136  and receiving from the MCM  136  a message indicating the motor torque and speed that can be provided in response to the request. In response to this message from the MCM  136 , the SCM may evaluate with conditional  208  whether the motor torque and speed that can be provided are sufficiently close to the requested motor torque and speed (e.g., within a predetermined margin) to successfully execute a shift event. 
     At conditional  208 , if SCM  138  evaluates that the requested torque and speed of the motor for execution of the shift event cannot be provided, it inhibits gear shifting and generates and transmits message  226  indicating that gear shifts are not inhibited and transmits the message to TCM  134  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . In response to message  226 , TCM  134  inhibits gear shifting and generates and transmits a message  229  to GSCM  132  via vehicle CAN  194  indicating that an operator perceptible indication that the gear shift is inhibited should be provided. In response to this message, the GSCM  132  provides an operator perceptible indication that the gear shift is inhibited, for example, providing an output on a display. 
     At conditional  208 , if SCM  138  evaluates that the requested torque and speed of the motor for execution of the shift event can be provided, it generates and sends a message to MCM  136  to provide the commanded motor torque and speed. SCM  138  also generates a message  222  indicating a commanded motor speed and a message  224  indicating a commanded motor torque and transmits the message  222  and the message  224  to TCM  134  over a CAN network such as vehicle CAN  194  or powertrain CAN  196 . In response to the message  222  and the message  224 , TCM  134 , at operation  210 , executes a gear shift, updates the current gear, and generates and transmits a message  211  to GSCM  132  via vehicle CAN  194  indicating the updated current gear. In response to this message, the GSCM  132  provides an operator perceptible indication of the updated current gear. 
     It shall be appreciated that the operations illustrated and described in connection with  FIG. 2  may provide a number of benefits for control over a vehicle system such as vehicle system  100 . In certain forms, a direction of vehicle operation is determined by the foregoing acts of coordination among the supervisory control module, transmission control module, and gear shift control module. In certain forms, the powertrain (including the automated manual transmission) does not have a physical reverse gear and reverse operation of the vehicle system is provided by reverse rotation of the electric motor. In certain forms, the one or more acts of coordination include the supervisory control module comparing its internal vehicle direction state with an internal vehicle direction state of one or both of the one or both of the transmission control module and the gear shift control module and inhibiting vehicle operation if the compared vehicle direction states differ from one another. In certain forms, the supervisory control module and the transmission control module assume the same internal vehicle direction state once the vehicle system direction request from the driver has been accepted as a result of the operations illustrated and described in connection with  FIG. 2 . In certain forms, the supervisory control module is configured to spin the motor in the reverse direction once the vehicle system direction request has been accepted and a selected reverse gear has been engaged it being appreciated that the selected reverse gear may be a forward gear which is driven in reverse by the motor. In certain forms, the supervisory control module prevents erroneous vehicle operation in the direction not requested by a vehicle operator. In certain forms, the supervisory control module prevents erroneous vehicle operation by comparing its internal vehicle direction state with an internal vehicle direction state of the transmission control module. In certain forms, the supervisory control module prevents erroneous vehicle operation by comparing its internal vehicle direction state with an internal vehicle direction state of the gear shift control module. In certain forms, the supervisory control module is configured to transmit signals with the appropriate sign convention for forward, reverse, and neutral states. In certain forms the sign convention is applied to signals include for torque, speed and/or other rotational parameters. In certain forms, the supervisory control module is configured to move into the neutral state after a key on/off event. In certain forms, the supervisory control module is configured to maintain zero vehicle speed for a configurable period of time by providing torque commands to the motor while the vehicle system is positioned on a grade greater than a predetermined magnitude, for example, a grade of 2% or greater, a grade of 3% or greater, a grade of 4% or greater or another predetermined grade. 
     With reference to  FIG. 3 , there is illustrated a schematic diagram illustrating certain aspects of example supervisory control logic  300  which may be implemented in and executed by the SCM  138 . Supervisory control logic includes  300  includes EV AMT supervisor block  302  which receives a plurality of inputs via vehicle CAN  194  or a CAN network of the low voltage wiring harness  191  including, operator commands or driver request, power limits, look-ahead information, and motor information such as motor current, motor speed, motor power and motor temperature, and battery information such as battery current, battery power, battery state of charge, and battery state of health. EV AMT supervisor block  302  utilizes the received inputs to determine a plurality of outputs and transmits these outputs via vehicle CAN  194  or low voltage wiring harness  191  including system power limits or operating limits, a shift inhibit request, requested gear based on look-ahead information and the currently selected gear, and rate limits for torque interrupts. 
     EV AMT supervisor block  302  may determine the system power limits or operating limits based upon one or more motor limits such as a motor current limit, a motor speed limit, a motor power limit, and/or a motor temperature limit. EV AMT supervisor block  302  may determine the system power limits or operating limits based upon one or more battery limits such as a battery current limit, a battery power limit, a battery state of charge limit, and a battery state of health limit. EV AMT supervisor block  302  may determine the shift inhibit request based upon an evaluation of a supervisory transmission mode change inhibit condition (STXI) as described above in connection with process  200 . EV AMT supervisor block  302  may determine the requested gear based on look-ahead information and the currently selected gear by evaluating a predicted vehicle load based in part upon a future road grade, determining a desired gear based upon the predicted vehicle load and the current engine speed and current engine load, and determining a requested gear shift based upon the desired gear and the current gear. EV AMT supervisor block  302  may determine the rate limits for torque interrupts based upon operational limits of the motor and/or the battery which may include predetermined limits and which may be based upon the present operational state of the motor and/or the battery. 
     The supervisory control logic includes  300  includes torque and acceleration request block  306  which receives one or more motor torque, speed (N) or acceleration (NDOT) requests and associated priorities from TCM  134  via vehicle CAN  194  or low voltage wiring harness  191 . Torque and acceleration request block  306  outputs a set of one or more acceleration (NDOT) requests  308  and a set of corresponding torque requests  310  based on the inputs that it receives and provides these outputs to arbitration block  312  which selects winning torque and NDOT request from the inputs that it receives. Arbitration block  312  may select winning torque and NDOT requests in accordance with the techniques described hereinabove in connection with SCM  138 . Arbitration block  312  provides the selected winning request to NDOT inner loop controller  314  which determines motor torque and speed or acceleration values based on the inputs that it receives. These motor torque and speed or acceleration values are provided to limiter block  316  which imposes limits on the motor torque and speed or acceleration values. The limited motor torque and speed or acceleration values are provided to power split and system limits block  318  which uses power split logic, system limits logic, and operating modes logic to determine torque and speed commands  320  for motor  126  which are provided to MCM  136  via low voltage wiring harness  191 . 
     With reference to  FIG. 4 , there is illustrated a schematic diagram depicting certain aspects of low voltage wiring harness  191 . In  FIG. 4  lines  411  indicate analog bus inputs/outputs, lines  413  indicate digital bus inputs/outputs, lines  411  indicate CAN busses with inline terminations, lines  414  indicate protective circuits or fuses, and lines  415  indicate grounded power connections.  FIG. 4  further illustrates a low voltage battery  427  which is connected to one of lines  415  in addition to the power provided by ESS  127 . 
     A first example embodiment is a vehicle system comprising: a powertrain including an electric motor operatively coupled with an automated manual transmission; and an electronic control system including a gear shift control module, a transmission control module, and a motor control module operative communication with one another over one or more controller area networks; wherein the electronic control system includes supervisory controls configured to: arbitrate between a plurality of motor operation requests received over the one or more controller area networks to select a winning motor operation request, the plurality of motor operation requests including an operator torque request, evaluate one or more shift inhibit conditions, and command the electric motor to provide the winning motor operation request when none of the one or more shift inhibit conditions evaluate as true. 
     In a second form of the first example embodiment, the supervisory controls are configured to command the electric motor to provide the winning motor operation request by ramping up or down from current motor torque, speed, and power values to new motor torque, speed and torque values corresponding to the winning motor operation request. 
     In a third form of the first example embodiment, the supervisory controls are configured to (a) in response to a gear shift request, suspend a non-shifting response of the motor control module to an operator torque request, and (b) terminate the suspension of the non-shifting response of the motor control module in response to the completion of a gear shift. 
     In a fourth form of the first example embodiment, the one or more inhibit conditions comprise one or more of: a battery state of charge (SOC) being below an SOC limit, a battery contactor being open, a key switch being off, one or more system power limits being below a system power limit, a battery charging system being connected, one or more system faults being active, service brakes being inactive and an operator command to drive being true, an operator requested vehicle direction changes while the vehicle system is not stationary, and look-ahead information indicating that a gear shift should be inhibited. 
     In a fifth form of the first example embodiment, at least one of the one or more controller area networks is provided by a low voltage wiring harness. 
     In a sixth form of the first example embodiment, the one or more controller area networks include a vehicle controller area network, a powertrain controller area network, a service controller area network, and a private controller area network. 
     In a seventh form of the first example embodiment, at least one of the one or more controller area networks is provided by a low voltage wiring harness. 
     In an eighth form of the first example embodiment, the supervisory controls are implemented in the motor control module. 
     In a ninth form of the first example embodiment, one of (a) the powertrain includes one of an engine and a fuel cell, (b) the powertrain is configured as a range-extended electric drive system including an engine configured to drive a generator to provide electrical power to the motor, and (c) the powertrain is configured as a parallel hybrid drive system wherein either or both of an engine and the electric motor are operable to provide torque to propel the vehicle system. 
     In a tenth form of the first example embodiment, the supervisory controls are provided in a supervisory control module, the supervisory control module and the motor control module being physically separate devices. 
     In an eleventh form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the powertrain does not have a physical reverse gear, and reverse operation of the vehicle system is provided by reverse rotation of the electric motor. 
     In a twelfth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, a direction of vehicle operation is determined by one or more acts of coordination among the supervisory controls, the transmission control module, and the gear shift control module. In a refinement, the one or more acts of coordination include the supervisory controls comparing a first vehicle direction state internal to the supervisory controls with a second internal vehicle direction state of one of the transmission control module and the gear shift control module. 
     In a thirteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls and the transmission control module assume the same internal vehicle direction state once the vehicle system direction request from the driver has been accepted by the system. 
     In a fourteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls are configured to spin the motor in a reverse direction once the vehicle system direction request has been accepted and the selected reverse gear has been engaged. 
     In a fifteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls prevent erroneous vehicle operation in the direction not requested by a vehicle operator. 
     In a sixteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls prevent erroneous vehicle operation by comparing a first internal vehicle direction state with a second internal vehicle direction state of the transmission control module. 
     In a seventeenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls are configured to transmit signals for at least one of torque, speed, and other rotational engine parameters with a sign convention indicating one of a forward state, a reverse state, and a neutral state. 
     In an eighteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls are configured to at least one of initialize into a neutral state after a key-on event, and move into a neutral state after a key-off event and prior to completing a system power down. 
     In a nineteenth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the supervisory controls are configured to maintain zero vehicle speed for a configurable period of time by providing torque commands to the motor while the vehicle system is positioned on a grade greater than a predetermined magnitude. 
     In a twentieth form of any of the first example embodiment or the second through tenth forms of the first example embodiment, the gear shift control module is configured to generate a message indicating a requested transmission mode in response to an operator command and to transmit the message to the transmission control module and the supervisory controls via the one or more controller area networks. 
     In a refinement of the twentieth form, the supervisory controls evaluate whether a transmission mode change inhibit request is true and, if the transmission shift inhibit request is true, generate a message indicating that transmission mode changes are inhibited and transmit the message to the transmission control module via the one or more controller area networks. 
     In a refinement of the twentieth form, the supervisory controls evaluate whether a transmission mode change inhibit request is true and, if the transmission mode change inhibit request is not true, the supervisory controls generate a message indicating that gear shifts are not inhibited and transmits the message to the transmission control module over via the one or more controller area networks and, in response to the message the transmission control module evaluates whether an internal shift inhibit condition is true. In another refinement, the supervisor control module receives via the or more controller area networks one or more signals indicating the current gear of the transmission, the selected gear for the shift event, an indication whether a shift event is in progress, and a requested torque and speed of the motor for execution of the shift event and, in response, the supervisory controls evaluate whether the requested torque and speed of the motor for execution of the shift event can be provided. In another refinement, one of (a) if the supervisory controls evaluate that the requested torque and speed of the motor for execution of the shift event cannot be provided, the supervisory controls inhibit gear shifting and generates and transmit a message to the gear shift control module via the one or more controller area networks indicating that an operator perceptible indication that the gear shift is inhibited should be provided, and (b) if the supervisory controls evaluate that the requested torque and speed of the motor for execution of the shift event can be provided, the supervisory controls generate and send a message to the motor control module to provide the commanded motor torque and speed, and generate and send a message to the transmission control module indicating the commanded motor torque and speed. 
     A second example embodiment is a method of controlling the operation of a vehicle powertrain, the method comprising: operating an electronic control system to control an electric motor of the vehicle system powertrain to provide torque to an automated manual transmission, the electronic control system including a gear shift control module, a transmission control module, and a motor control module in operative communication with one or more controller area networks, the electronic control system including supervisory controls implemented in one or both of the motor control module and a supervisory control module in operative communication with the one or more controller area networks; operating the supervisory controls to arbitrate between a plurality of motor operation requests received over the one or more controller area networks to select a winning motor operation request, the plurality of motor operation requests including an operator torque request, operating the supervisory controls to evaluate one or more shift inhibit conditions, and operating the supervisory controls to command the electric motor to provide the winning motor operation request when none of the one or more shift inhibit conditions evaluate as true. 
     A second form of the second example embodiment comprises: operating the supervisory controls to command the electric motor to provide the winning motor operation request by ramping up or down from current motor torque, speed, and power values to new motor torque, speed and torque values corresponding to the winning motor operation request. 
     A third form of the second example embodiment comprises: operating the supervisory controls to (a) suspend a non-shifting response of the motor control module to an operator torque request in response to a gear shift request, and (b) terminate the suspension of the non-shifting response of the motor control module in response to the completion of a gear shift. 
     In a fourth form of the second example embodiment, the one or more inhibit conditions comprise one or more of: a battery state of charge (SOC) being below an SOC limit, a battery contactor being open, a key switch being off, one or more system power limits being below a system power limit, a battery charging system being connected, one or more system faults being active, service brakes being inactive and an operator command to drive being true, an operator requested vehicle direction changes while the vehicle system is not stationary, and look-ahead information indicating that a gear shift should be inhibited. 
     In a fifth form of the second example embodiment, at least one of the one or more controller area networks is provided by a low voltage wiring harness. 
     In a sixth form of the second example embodiment, the one or more controller area networks include a vehicle controller area network, a powertrain controller area network, a service controller area network, and a private controller area network. 
     In a seventh form of the second example embodiment, at least one of the one or more controller area networks is provided by a low voltage wiring harness. 
     In an eighth form of the second example embodiment, the supervisory controls are implemented in the motor control module. 
     In a ninth form of the second example embodiment, one of (a) the powertrain includes one of an engine and a fuel cell, (b) the powertrain is configured as a range-extended electric drive system wherein an engine is configured to drive a generator to provide electrical power to the motor, and (c) the powertrain is configured as a parallel hybrid drive system wherein either or both of an engine and the electric motor are operable to provide torque to propel the vehicle system. 
     In a tenth form of the second example embodiment, the motor control module and the supervisory control module are provided in physically separate devices and the supervisory controls are implemented in the supervisory control module. 
     In an eleventh form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the powertrain does not have a physical reverse gear, and reverse operation of the vehicle system is provided by reverse rotation of the electric motor. 
     In a twelfth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, a direction of vehicle operation is determined by one or more acts of coordination among the supervisory controls, transmission control module, and gear shift control module coordinate. In a refinement, the one or more acts of coordination include the supervisory controls comparing a first vehicle direction state internal to the supervisory controls with a second vehicle direction state internal to one or both of the transmission control module and the gear shift control module. 
     In a thirteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls and the transmission control module assume the same internal vehicle direction state once the vehicle system direction request from the driver has been accepted by the system. 
     In a fourteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls spin the motor in the reverse direction once the vehicle system direction request has been accepted and the selected reverse gear has been engaged. 
     In a fifteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls prevent erroneous vehicle operation in the direction not requested by a vehicle operator. 
     In a sixteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls prevent erroneous vehicle operation by comparing its internal vehicle direction state with an internal vehicle direction state of the transmission control module. 
     In a seventeenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls transmit signals for one or more of torque and speed with a sign convention indicating one of a forward state, a reverse state, and a neutral state. 
     In a eighteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls at least one of initialize into a neutral state after a key-on event, and move into a neutral state after a key-off event and prior to completing a system power down. 
     In a nineteenth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the supervisory controls maintain zero vehicle speed for a configurable period of time by providing torque commands to the motor while the vehicle system is positioned on a grade greater than a predetermined magnitude. 
     In a twentieth form of the second example embodiment or any of the second through tenth forms of the second example embodiment, the gear shift control generates a message indicating a requested transmission mode in response to an operator command and to transmits the message to the transmission control module and the supervisory controls via the one or more controller area networks. 
     In a refinement of the twentieth form, the supervisory controls evaluate whether a transmission shift inhibit request is true and one of (a) if the shift inhibit request is true, generate a message indicating that shifting is inhibited and transmit the message to the transmission control module via the one or more controller area networks, and (b) if shift inhibit request is not true, generate a message indicating that gear shifts are not inhibited and transmit the message to the transmission control module via the one or more controller area networks, wherein, in response to the message, the transmission control module evaluates whether an internal shift inhibit condition is true. In another, the supervisor control module receives via the or more controller area networks one or more signals indicating the current gear of the transmission, the selected gear for the shift event, an indication whether a shift event is in progress, and a requested torque and speed of the motor for execution of the shift event and, in response, the supervisory controls evaluate whether the requested torque and speed of the motor for execution of the shift event can be provided. In another refinement, if the supervisory controls evaluate that the requested torque and speed of the motor for execution of the shift event cannot be provided, the supervisory controls inhibits gear shifting and generates and transmits a message to the gear shift control module via the one or more controller area networks indicating that an operator perceptible indication that the gear shift is inhibited should be provided. In another refinement, if the supervisory controls evaluate that the requested torque and speed of the motor for execution of the shift event can be provided, supervisory controls generate and sends a message to the motor control module to provide the commanded motor torque and speed, and generates and sends a message to the transmission control module indicating the commanded motor torque and speed. 
     While illustrative embodiments of the disclosure have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain example embodiments have been shown and described and that all changes and modifications that come within the spirit of the claimed inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicates that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.