Systems and methods for controlling towing of a vehicle

Various disclosed embodiments include systems, vehicles, and methods for controlling towing of a vehicle without an electrical connection between a tow vehicle and a towed vehicle. In an illustrative embodiment, a system includes a controller. The controller includes a processor and computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive sensed data indicative of at least one attribute of a tow vehicle without an electrical connection between the tow vehicle and a towed vehicle; and control an attribute of the towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle.

INTRODUCTION

The present disclosure relates to towing an electric vehicle.

When a motor vehicle is being towed behind a tow vehicle, signal lights (that is, brake lights, turn signals, and backing lights) and braking of the towed vehicle currently are synchronized with the tow vehicle via an external electrical connection between the tow vehicle and the towed vehicle and with aftermarket equipment, such as auxiliary braking systems.

When an electric vehicle driven by permanent magnet synchronous motors is towed, back electromotive force (back emf) is generated that, beyond a certain motor speed, may be higher than voltage of a high voltage high voltage (HV) direct current (DC) bus and, if uncontrolled, could cause energy to flow back into the battery in an uncontrolled manner. Further, uncontrolled back emf that is not consumed into the battery may subject inverter components or other components on the HV DC bus to voltages that may be greater than their designed voltage ranges.

Moreover, constant, uncontrolled application of regenerative braking torque in a towed electric vehicle can cause additional fuel to be consumed by the tow vehicle and can possibly add to instability of the towed electric vehicle by adding sway.

BRIEF SUMMARY

Various disclosed embodiments include systems, vehicles, and methods for controlling towing of a vehicle without an electrical connection between a tow vehicle and a towed vehicle.

In an illustrative embodiment, a system includes a controller. The controller includes a processor and computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive sensed data indicative of at least one attribute of a tow vehicle without an electrical connection between the tow vehicle and a towed vehicle; and control an attribute of the towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle.

In another illustrative embodiment, a vehicle includes rotatable wheels and at least one drive unit. The at least one drive unit includes at least one inverter, at least one electric motor electrically couplable to the at least one inverter and rotatably couplable to at least one of the rotatable wheels, and at least one inverter controller configured to control the at least one inverter. The vehicle also includes at least one sensor and a controller. The controller includes a processor and computer-readable media configured to store computer-executable instructions configured to cause the processor to: receive sensed data indicative of at least one attribute of a tow vehicle without an electrical connection between the tow vehicle and the towed vehicle; and control an attribute of a towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle.

In another illustrative embodiment, a method includes: sensing data indicative of at least one attribute of a tow vehicle without an electrical connection between the tow vehicle and the towed vehicle; and controlling an attribute of a towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle.

Like reference symbols in the various drawings generally indicate like elements.

DETAILED DESCRIPTION

Various disclosed embodiments include systems, vehicles, and methods for controlling towing of a vehicle without an electrical connection between a tow vehicle and a towed vehicle.

By way of nonlimiting overview and referring toFIGS.1and2, in various embodiments an illustrative system includes a controller64. The controller64includes a processor66and computer-readable media68configured to store computer-executable instructions configured to cause the processor66to: receive sensed data indicative of at least one attribute of a tow vehicle12without an electrical connection between the tow vehicle12and a towed vehicle10; and control an attribute of the towed vehicle10responsive to the sensed data indicative of a corresponding attribute of the tow vehicle12.

Illustrative details regarding the vehicle10(to be towed) will be explained first by way of illustration only and not of limitation. Then, illustrative details regarding controlling the towing of the vehicle10without an electrical connection between the tow vehicle12and the towed vehicle10and controlling the inverter56of the towed vehicle10will be explained by way of illustration only and not of limitation.

The present disclosure refers to “deceleration.” As used herein, deceleration is negative acceleration.

As shown inFIG.1, the vehicle10is towable behind12tow vehicle12. In various embodiments the vehicle10may be any suitable electric vehicle, such as, for example, an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, and the like. However, it will be appreciated that, as explained below, in some embodiments the vehicle10may be any type motor vehicle whatsoever regardless of source of propulsion and may also include vehicles powered by an internal combustion engine, such as a spark-ignition engine or a compression-ignition engine, a fuel cell, natural gas, propane, or the like. Regardless of propulsion source, the vehicle10may be any type of towable motor vehicle whatsoever as desired, such as, for example and without limitation, a car, a truck, a sport-utility vehicle, a van, a motorhome, a bus, or the like.

In various embodiments, the tow vehicle12may be any type of motor vehicle (that is capable of towing another motor vehicle) whatsoever as desired, such as, for example and without limitation, a car, a truck, a sport-utility vehicle, a van, a motorhome, a bus, or the like. The tow vehicle12includes various signal lights14disposed about an aft end16of the tow vehicle12. The signal lights14are configured to illuminate and convey information to others regarding actions of the tow vehicle12and intentions of a driver of the tow vehicle12. For example, the signal lights14suitably include brake lights18, turn signals20, and a backing light22.

The vehicle10is suitable tethered to the tow vehicle12via a tow bar24. The tow bar24includes a shank26having a forward end28and an aft end30. The tow bar24also includes arms32that each have a forward end34and an aft end36. The arms32are attached at their forward ends34to the aft end30of the shank26.

A hitch receiver38is attached to a lower portion40of the aft end16of the tow vehicle12. A base plate (not shown for purposes of clarity) having a cross member42is attached to a lower portion44of a front end46of the vehicle10. The hitch receiver38evenly distributes towing loads to a frame (not shown for purposes of clarity) of the tow vehicle12and the base plate evenly distributes towing loads to a frame (not shown for purposes of clarity) of the vehicle10. The forward end28of the shank26is removably attached to the hitch receiver38and the aft ends36of the arms32are removably attached to the base plate. Safety cables48(such as steel cables or chains) suitably are removably attached to the hitch receiver38and the base plate to help prevent accidental and/or inadvertent disconnection of the towed vehicle10from the tow vehicle12.

As will be explained below, in various embodiments towing of the vehicle10can be controlled without an electrical connection between the tow vehicle12and the vehicle10and, in various embodiments, the inverter56of the vehicle10can likewise be controlled without an electrical connection between the tow vehicle12the vehicle10. As such, it will be appreciated that, in various embodiments, the vehicle10can be towed behind the tow vehicle12at highway speeds without an electrical connection between the tow vehicle12the vehicle10and without use of aftermarket equipment.

As shown inFIG.2A, in various embodiments and as an initial, high-level introductory example the vehicle10includes a high-voltage, direct current (DC) electrical battery50, rotatable wheels52, and at least one drive unit54. Each drive unit54suitably includes at least one inverter56electrically couplable to the battery50. Each inverter56suitably includes three-terminal power semiconductor devices (not shown inFIG.2A). Each drive unit54also suitably includes at least one electric motor58electrically couplable to the at least one inverter56and rotatably couplable to at least one of the rotatable wheels52. Each drive unit54also includes at least one inverter controller60configured to control the at least one inverter56. The vehicle10also includes at least one sensor62and a controller64(such as an electronics control unit or ECU). The controller64includes a processor66and computer-readable media68configured to store computer-executable instructions.

Now that an initial, high-level introductory example of the vehicle10has been set forth, additional details will be explained by way of non-limiting examples provided by way of illustration only and not of limitation.

As also shown inFIG.2A, in various embodiments the battery50includes a high-voltage DC electrical battery. In such embodiments, the battery50is configured to provide high-voltage DC electrical power, such as on the order of around 450 volts or so via a high voltage (HV) DC bus51. In various embodiments the battery50may include a lithium-ion battery. However, it will be appreciated that the battery50may include any suitable battery as desired and that further description of the battery is not necessary for a person of skill in the art to understand disclosed subject matter.

In various embodiments the vehicle10includes the electronics control unit (ECU)64that controls operations of various components via a peer-to-peer network bus70such as a controller area network (CAN) bus. Other peer-to-peer network buses, such as a local area network (LAN), a wide area network (WAN), or a value-added network (VAN), may also be used for enabling communication between the ECU64and the components connected to the peer-to-peer network bus70.

In various embodiments the processor66may include a computer processing unit (CPU), a general purpose processor, a digital signal processor, a field programmable gate array, or the like, and/or any combination thereof. Processors are well known and further description of their construction and operation are not necessary for an understanding by a person of skill in the art of disclosed subject matter.

In various embodiments the computer-readable media68may include any suitable computer memory configured to store computer-executable instructions configured to cause the processor66to perform functions described herein. Given by way of non-limiting examples, the computer-readable media68may include any suitable volatile memory elements, such as without limitation random access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), static-dynamic RAM (SDRAM), and the like, nonvolatile memory elements such as without limitation read-only-memory (ROM), hard drive, tape, compact-disc ROM (CDROM), and the like, and combinations thereof. Moreover, the computer-readable media18may incorporate electronic, magnetic, optical, and/or other types of storage media as desired.

In various embodiments the ECU64communicates via the peer-to-peer network bus70with a human-machine interface (HMI)72. In various embodiments and given by way of example only and not of limitation, the HMI72may include mechanical buttons or switches or may include selectable graphical user interface features presented on a vehicle display device(s).

In various embodiments the ECU64communicates via the peer-to-peer network bus70with a battery management unit (BUM)74. In various embodiments and given by way of example only and not of limitation, the BMU74communicates with the battery50to generate battery status information, which is sent to the ECU64via the peer-to-peer network bus70. The BMU74receives battery information from the battery50and/or from any sensors (not shown for purposes of clarity) associated with or included in the battery50. The battery information may include state of charge (SOC), temperature, voltage of battery cells, input/output current, coolant flow, or other values related to battery operations. The BMU74uses the battery information to control battery recharging and battery thermal management and to communicate with other components of the vehicle10via the peer-to-peer network bus70or with external components or other systems or devices as desired.

In various embodiments, the ECU64communicates with a brake system76directly or via the peer-to-peer network bus70. In various embodiments the brake system76may include a foot pedal (not shown for purposes of clarity), a brake solenoid or pressure sensor (not shown for purposes of clarity), a handbrake (not shown for purposes of clarity), a steering wheel-mounted brake paddle (not shown for purposes of clarity), or comparable brake components (not shown for purposes of clarity), and friction brakes (not shown for purposes of clarity). In various embodiments, if desired, the brake system76may be a brake-by-wire system or any type of brake system as desired.

In various embodiments, a DC/DC converter78is electrically coupled to the battery50to provide DC electrical power at an appropriate DC voltage level (such as, for example and without limitation, around 12 VDC or so) to various auxiliary loads that are to be energized while the vehicle10is being towed, such as various control units, external lighting systems, coolant pumps for cooling the drive units54and their components, and the like.

In various embodiments the drive unit54may include one or more inverters56, one or more position sensors80such as a resolver, and one or more electric motors58, such as without limitation brushless direct current (BLDC) motors, alternating current induction motors (ACIM), permanent magnet (PM) synchronous motors (PMSM), interior PM motors (IPMM), PM switch reluctance motors (PMSRM), or any suitable electric motors whatsoever as desired. A back emf sensor94is configured to sense and measure back emf of an associated electric motor58when the electric motor58is functioning as a generator.

The drive unit54also includes at least one inverter controller60electrically coupled to the inverter(s)56and the position sensor(s)80. The inverter controller60includes a processor61and computer-readable media63configured to store computer-executable instructions configured to cause the processor61to perform functions described herein. In various embodiments, the ECU64communicates with the inverter controller60via the peer-to-peer network bus70to cause the inverter controller60to perform various functions described herein. A drive member82, such as an axle or the like, is rotatably coupled to the electric motor58. At least one propulsion wheel52is rotatably couplable to the drive member82.

It will be appreciated that, if desired, one or more of the wheels52suitably may be rotatably disconnectable as desired from an associated electric motor58, thereby preventing the associated motor58from rotating while the vehicle10is being towed. However, in various embodiments at least one electric motor58is rotatable by its associated wheel52while the vehicle10is towed, thereby providing for application of regenerative braking and charging of the battery50as desired and as further explained below.

Referring additionally toFIG.2B, in various embodiments the signal lights14of the vehicle10may also include, without limitation, at least one of the brake lights18, at least one of the turn signals20(FIG.1), and the backing light22. In various embodiments, the ECU64communicates with the signal lights14via the peer-to-peer network bus70to perform various functions described herein.

Referring additionally toFIG.2C, in various embodiments the sensors62may include any sensor desired for a particular application. For example and by way of non-limiting example, in various examples the sensors62may include, without limitation, a forward-facing camera84, an accelerometer86(that senses fore/aft acceleration and/or lateral acceleration), a vehicle speed sensor88, a wheel speed sensor90, and a motor speed sensor92. Also, in various embodiments the sensors62may include, without limitation, a radio detection and ranging (RADAR) sensor96, a light detection and ranging (LIDAR) sensor98, a sound detection and ranging (SODAR) sensor100, an ultrasound sensor102, and the like. In various embodiments, the ECU64communicates with the sensors62via the peer-to-peer network bus70to perform various functions described herein.

Now that the vehicle10has been described, controlling towing of the vehicle10without an electrical connection between the tow vehicle12and the vehicle10will be explained by way of non-limiting examples given by way of illustration only and not of limitation.

In various embodiments the computer-executable instructions are configured to cause the processor66to receive from the at least one sensor62sensed data indicative of at least one attribute of the tow vehicle12without an electrical connection between the tow vehicle12and the vehicle10and to cause the processor66to control an attribute of the vehicle10responsive to the sensed data indicative of a corresponding attribute of the tow vehicle12.

In some such embodiments, the signal lights14of the tow vehicle12and the signal lights14of the vehicle10can be synchronized. It will be appreciated that in such embodiments the vehicle10may be any type motor vehicle whatsoever regardless of source of propulsion and may also include vehicles powered by an internal combustion engine, such as a spark-ignition engine or a compression-ignition engine, a fuel cell, natural gas, propane, or the like (in addition to the electric vehicles described above).

In such embodiments, the tow vehicle attribute includes visual signaling, the sensor62includes a forward-facing camera84, and the data indicative of the tow vehicle attribute includes at least one datum such as visually detected illumination of at least one brake light18of the tow vehicle12, visually detected illumination of a turn signal20of the tow vehicle12, and visually detected illumination of a backing light of the tow vehicle12. It will be appreciated that, in various embodiments, data from the camera84may include image data and/or video data.

In such embodiments, the instructions are further configured to cause the processor66to cause illumination of a signal light of the vehicle10, such as at least one brake light18, a turn signal20, and a backing light22responsive to data indicative of a corresponding attribute (that is, illumination of a corresponding signal light14) of the two vehicle12.

In some other embodiments, braking of the tow vehicle12and braking of the vehicle10can be synchronized. It will be appreciated that in some such embodiments (discussed below) the vehicle10may be any type motor vehicle whatsoever regardless of source of propulsion and may also include vehicles powered by an internal combustion engine, such as a spark-ignition engine or a compression-ignition engine, a fuel cell, natural gas, propane, or the like (in addition to the electric vehicles described above).

In some such embodiments, the tow vehicle attribute includes deceleration and the at least one sensor62may include any one or more of the accelerometer86, the vehicle speed sensor88, the wheel speed sensor90, the motor speed sensor92, the back emf sensor94, and/or the forward-facing camera84.

In such embodiments, the data indicative of the tow vehicle attribute includes at least one datum such as sensed deceleration of the vehicle10from the accelerometer86, sensed vehicle speed of the vehicle10from the vehicle speed sensor88, sensed wheel speed of the vehicle10from the wheel speed sensor90, sensed motor speed of the vehicle10from motor speed sensor92, sensed back emf of one or more of the electric motors58of the vehicle10from the back emf sensor94, and visually detected illumination of at least one brake light18of the tow vehicle12from the forward-facing camera84.

In various such embodiments the instructions are further configured to cause the processor66to cause at least one action such as applying proportional braking via at least one braking process like application of friction brakes, application of regenerative braking, and illuminating at least one brake light responsive to data indicative of tow vehicle deceleration.

Illustrative details regarding synchronization of the brake light18of the tow vehicle12and the brake light of the vehicle10have been discussed above and are not repeated for sake of brevity.

In some such embodiments, responsive to data indicative of tow vehicle deceleration the processor66causes the brake system76to apply proportional braking via application of friction brakes. In such embodiments, the friction brakes may be part of a brake-by-wire system or part of any other type of brake system as desired.

It will be appreciated that, in embodiments that synchronize the brake light18of the tow vehicle12and the brake light of the vehicle10and that synchronize proportional braking via application of friction brakes, the vehicle10may be any type motor vehicle whatsoever regardless of source of propulsion and may also include vehicles powered by an internal combustion engine, such as a spark-ignition engine or a compression-ignition engine, a fuel cell, natural gas, propane, or the like (in addition to the electric vehicles described above).

In some other such embodiments, responsive to data indicative of tow vehicle deceleration the processor66causes the brake system76to apply proportional braking via application of regenerative braking. In such embodiments the ECU64communicates with the inverter controller60via the peer-to-peer network bus70to cause the processor61to control the inverter56to apply proportional regenerative braking. It will be appreciated that application of regenerative braking can help contribute to reducing wear of friction brakes of the vehicle10, thereby helping contribute to increasing life of friction brakes of the vehicle10. Details regarding regenerative braking will be discussed further below by way of illustration only and not of limitation.

In some other embodiments the vehicle10may be brought to a safe stop if the physical tow connection between the tow vehicle12and the vehicle10is broken. That is, the vehicle10may be brought to a safe stop if, when the vehicle10is being towed behind the tow vehicle12, the tow bar24breaks, or if the shank26of the tow bar24becomes disconnected from the hitch receiver38of the tow vehicle12, or if one or more of the arms32of the tow bar24become disconnected from the cross member42.

In such embodiments the tow vehicle attribute includes distance from the tow vehicle12to the vehicle10and the at least one sensor62includes at least one distance sensor such as the radar sensor96, the LIDAR sensor98, the SODAR sensor100, and the ultrasound sensor102. It will be appreciated that such sensors may be included in an Advanced Driver Assistance Systems (ADAS) suite of sensors. It will also be appreciated that some such sensors may also be referred to as front parking sensors and/or adaptive cruise control sensors. In such embodiments the data indicative of the tow vehicle attribute includes at least one datum such as sensed distance from the tow vehicle.

In such embodiments the instructions are further configured to cause the processor66to cause braking to be applied via at least one braking process such as application of friction brakes and/or application of regenerative braking responsive to sensed distance from the tow vehicle12differing from a predetermined distance, and the braking is sufficient to bring the vehicle10to a stop.

For example, in some such embodiments the predetermined distance may be the distance between the tow vehicle12and the vehicle10when the vehicle10is tethered to the tow vehicle with the tow bar24. If, when the vehicle10is being towed behind the tow vehicle12, the tow bar24breaks, or if the shank26of the tow bar24becomes disconnected from the hitch receiver38of the tow vehicle12, or if one or more of the arms32of the tow bar24become disconnected from the cross member42, then the distance between the tow vehicle12and the vehicle10will change.

For example, in some instances the towed vehicle12and the vehicle10will get farther away from each other as the vehicle10coasts and slows but the tow vehicle12continues to be driven. As another example, in some other instances the towed vehicle12and the vehicle10will get closer each other as the vehicle10coasts and slows (decelerates) but the tow vehicle12brakes or otherwise slows (decelerates) faster than the rate of slowing (or deceleration) of the vehicle10. Regardless, in either case, the processor66causes braking to be applied via at least one braking process such as application of friction brakes and application of regenerative braking responsive to sensed distance from the tow vehicle12differing from the predetermined distance, and the braking is sufficient to bring the vehicle10to a stop—thereby helping to secure a “runaway” vehicle10.

Referring additionally toFIG.3A, in various embodiments a method300is provided for controlling towing of a towed vehicle without an electrical connection between a tow vehicle and the towed vehicle. The method300starts at a block302. At a block304data indicative of at least one attribute of a tow vehicle is sensed without an electrical connection between the tow vehicle and the towed vehicle. At a block306an attribute of a towed vehicle is controlled responsive to the sensed data indicative of a corresponding attribute of the tow vehicle. The method300stops at a block308.

Referring additionally toFIG.3B, in various embodiments the tow vehicle attribute includes visual signaling and the sensed data indicative of the tow vehicle attribute includes at least one datum such as visually detected illumination of at least one brake light, visually detected illumination of a turn signal, and/or visually detected illumination of a backing light. In such embodiments, controlling an attribute of a towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle at the block306includes causing illumination of a signal light such as at least one brake light, a turn signal, and/or a backing light responsive to sensed data indicative of a corresponding tow vehicle attribute at a block310.

Referring additionally toFIG.3C, in various embodiments the tow vehicle attribute includes deceleration and the sensed data indicative of the tow vehicle attribute includes at least one datum such as sensed deceleration of the towed vehicle, sensed vehicle speed of the towed vehicle, sensed wheel speed of the towed vehicle, sensed motor speed of the towed vehicle, sensed back emf of an electric motor of the towed vehicle, and/or visually detected illumination of at least one brake light of the tow vehicle. In such embodiments, controlling an attribute of a towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle at the block306includes causing at least one action such as applying proportional braking via at least one braking process such as application of friction brakes and/or application of regenerative braking and/or illuminating at least one brake light responsive to data indicative of tow vehicle deceleration at a block312.

Referring additionally toFIG.3D, in various embodiments the tow vehicle attribute includes distance between the tow vehicle and the towed vehicle and the sensed data indicative of the tow vehicle attribute includes at least one datum chosen from sensed distance from the tow vehicle. In such embodiments, controlling an attribute of a towed vehicle responsive to the sensed data indicative of a corresponding attribute of the tow vehicle at the block306includes causing braking to be applied via at least one braking process such as application of friction brakes and/or application of regenerative braking responsive to sensed distance from the tow vehicle differing from a predetermined distance, the braking being sufficient to bring the towed vehicle to a stop at a block314.

Now that various embodiments of controlling towing of the vehicle10without an electrical connection between the tow vehicle12and the vehicle10have been explained by way of illustration only and not of limitation, various embodiments of controlling the inverter56of the vehicle10will be set forth below by way of illustration only and not of limitation.

In various embodiments the computer-executable instructions are configured to cause the processor66to receive sensed data indicative of detected deceleration of the tow vehicle12and, during detected deceleration, control the inverter56of the vehicle10responsive to the detected deceleration—such as to apply regenerative braking during the detected deceleration and/or to charge the battery50during the detected deceleration.

In some such embodiments, the at least one sensor62includes at least one sensor such as the accelerometer86, the vehicle speed sensor88, the wheel speed sensor90, the motor speed sensor92, the back emf sensor94, and the camera84. In such embodiments, the sensed data indicative of detected deceleration of the tow vehicle can include data such as sensed deceleration of the vehicle10from the accelerometer86, sensed vehicle speed of the vehicle10from the vehicle speed sensor88, sensed wheel speed of the vehicle10from the wheel speed sensor90, sensed motor speed of the vehicle10from motor speed sensor92, sensed back emf of one or more of the electric motors58of the vehicle10from the back emf sensor94, and visually detected illumination of at least one brake light18of the tow vehicle12from the forward-facing camera84.

Referring additionally toFIG.4, in various embodiments the inverter56includes switches400. In various embodiments the switches400may include any suitable inverter switch as desired, such as without limitation metal-oxide-semiconductor (MOS) field-effect transistors (FETs) (MOSFETs) and/or insulated-gate bipolar transistors (IGBTs), or the like, as desired for a particular application. The switches400are shown for purposes of illustration only and are not intended to represent any particular switching condition or configuration. It will be appreciated that the switches400may be switched via drive signals provided to gate terminals (not shown for purposes of clarity) of the switches400from a gate drive circuit (not shown for purposes of clarity) within or driven by the inverter controller60. In various embodiments, the gate terminals of the switches400may be driven via any modulation scheme as desired, such as, without limitation, pulse width modulation or the like.

Given by way of illustration only and not of limitation, during towing of the towed vehicle10when deceleration is not detected, the switches400are activated by the inverter controller60to generate zero torque and to minimize back emf with respect to speed, thereby helping allow the vehicle10to be towed at higher speeds (such as at highway speeds). In various embodiments, a small amount of electrical energy is put into the electric motor58to cancel losses generated by the electric motor58being rotated in order to effect zero mechanical output from the electric motor58. As such, in such embodiments the battery50is electrically connected to the HV DC bus51while the vehicle10is being towed, thereby helping prevent components of the inverter56and components of the HV DC bus51from being subjected to voltages that may be greater than their designed voltage ranges.

Also given by way of illustration only and not of limitation, in various embodiments, during deceleration, deceleration is detected as described above. In response to the detected deceleration, the ECU64issues a negative torque request (proportional to the amount of detected deceleration) to the inverter controller60. Energy is produced by the electric motor58when subjected to the negative torque request. This imparts negative torque at the drive member82(that is, regenerative braking), which produces electrical energy that is returned to the battery50, thereby charging the battery50.

In view of the illustrative examples set forth above, in various embodiments the computer-executable instructions are configured to cause the processor66to, during detected deceleration, control the inverter56of the vehicle10responsive to the detected deceleration—such as to apply regenerative braking during the detected deceleration and/or to charge the battery50during the detected deceleration. Thus, in various embodiments the battery50is not charged when deceleration is not detected and regenerative braking is not applied when deceleration is not detected.

In various embodiments the instructions are further configured to cause the processor66to, responsive to the detected deceleration and during the detected deceleration, cause the inverter controller60to control activation of the switches400, during the detected deceleration, in inverters56for electric motors58that are rotatable during towing. In some such embodiments, the instructions are further configured to cause the processor66to, responsive to the detected deceleration, apply regenerative braking during the detected deceleration. As described above, in various embodiments an amount of regenerative braking is proportional to an amount of the detected deceleration. In various embodiments, the processor66causes the inverter controller60to control the inverter56to generate an amount of regenerative braking that is proportional to an amount of the detected deceleration.

In various embodiments the instructions are further configured to cause the processor66to, responsive to the detected deceleration, during the detected deceleration charge the electrical battery50with electrical power generated by electric motors58that are rotatable during towing.

In such embodiments, an amount of electrical power supplied to charge the electrical battery is limited to a threshold amount of electrical power—such as an amount of electrical power used by various low voltage electrical loads energizable during towing, such as, for example, various control units, external lighting systems, coolant pumps for cooling the drive units54and their components, and the like. For example, in various embodiments the BMU74communicates SOC to the ECU64. When SOC of the battery50has been replenished (such as by the threshold amount of electrical power) to a desired SOC, the processor66causes charging of the battery50to stop. Thus, various embodiments can help allow avoiding depletion of the battery50and still have functionality of the various low voltage electrical loads.

In various embodiments the processor66causes the inverter controller60to control the inverter56to generate zero torque (that is, effect zero mechanical output from the electric motor58) when deceleration is no longer detected as described above.

Referring additionally toFIG.5A, in various embodiments a method500is provided for controlling an inverter of a towed vehicle. The method500starts at a block502. At a block504data indicative of detected deceleration of a tow vehicle is sensed. At a block506during detected deceleration, an inverter of a towed vehicle is controlled responsive to the detected deceleration. The method500stops at a block508.

Referring additionally toFIG.5B, in various embodiments at a block510the sensed data indicative of detected deceleration of the tow vehicle is received by a controller.

Referring additionally toFIG.5C, in various embodiments detecting deceleration of the tow vehicle at the block510includes at least one sensing action such as sensing deceleration of the towed vehicle, sensing vehicle speed of the towed vehicle, sensing wheel speed of the towed vehicle, sensing motor speed of the towed vehicle, sensing back emf of an electric motor of the towed vehicle, and/or visually detecting illumination of at least one brake light of the tow vehicle at a block512.

Referring additionally toFIG.5D, in various embodiments controlling an inverter of a towed vehicle responsive to the detected deceleration at the block506includes activating switches in inverters for electric motors that are rotating at a block514.

Referring additionally toFIG.5E, in various embodiments at a block516regenerative braking is applied to the towed vehicle. In various embodiments an amount of regenerative braking is proportional to an amount of the detected deceleration.

Referring additionally toFIG.5F, in various embodiments at a block518an electrical battery of the towed vehicle is charged with electrical power generated by electric motors that are rotating. In various embodiments an amount of electrical power supplied to charge the electrical battery is limited to a threshold amount of electrical power, such as an amount of electrical power used by electrical loads energized during towing.

While the disclosed subject matter has been described in terms of illustrative embodiments, it will be understood by those skilled in the art that various modifications can be made thereto without departing from the scope of the claimed subject matter as set forth in the claims.