COORDINATED CONTROL OF VEHICLE AND TRAILER ELECTRIC MACHINES

A controller commands an electric machine of a vehicle to produce propulsive torque with energy from a traction battery of the vehicle and, at a same time, commands an electric machine of a trailer coupled with the vehicle to produce regenerative torque such that a speed of the vehicle does not change.

TECHNICAL FIELD

The present disclosure relates to a system and method for operating a trailer electric vehicle.

BACKGROUND

Electric vehicles are propelled by electric energy stored in a vehicle battery having limited storage capability. When towing a trailer, the driving range of the electric vehicle may decrease due to the extra weight. In addition, the weight of the trailer may create challenges for the thermal management of the powertrain.

SUMMARY

A vehicle includes an electric machine, a traction battery, and a controller that commands the electric machine to produce propulsive torque with energy from the traction battery and, at a same time, commands an electric machine of a trailer coupled with the vehicle to produce regenerative torque such that a speed of the vehicle does not change.

A vehicle, mechanically coupled to a trailer having a trailer computer and a trailer battery, includes a vehicle motor, a vehicle battery that supplies and receives electric charge from the vehicle motor, and a controller. The controller is in communication with the trailer computer and commands a transfer of electric charge between the trailer battery and the vehicle battery based on data about a route to be travelled by the vehicle.

A method includes, responsive to a state of charge of a traction battery of a vehicle being less than a state of charge of a battery of a trailer coupled to the vehicle, commanding an electric machine of the trailer to provide propulsive torque with energy from the battery and commanding an electric machine of the vehicle to provide regenerative torque such that a speed of the vehicle remains same.

DETAILED DESCRIPTION

FIG.1depicts an electrified vehicle112that may be referred to as a plug-in hybrid-electric vehicle (PHEV), a battery electric vehicle (BEV), a mild hybrid-electric vehicle (MHEV), and/or full hybrid electric vehicle (FHEV). The plug-in hybrid-electric vehicle112may include one or more electric machines114mechanically coupled to a hybrid transmission116. The electric machines114may be capable of operating as a motor or a generator. In addition, the hybrid transmission116is mechanically coupled to an engine118. The hybrid transmission116is also mechanically coupled to a drive shaft120that is mechanically coupled to the wheels122. The electric machines114can provide propulsion and braking capability when the engine118is turned on or off. The electric machines114may also act as generators and can provide fuel economy benefits by recovering energy that would normally be lost as heat in a friction braking system. The electric machines114may also reduce vehicle emissions by allowing the engine118to operate at more efficient speeds and allowing the hybrid-electric vehicle112to be operated in electric mode with the engine118off under certain conditions.

A traction battery or battery pack124may store energy that can be used by the electric machines114. The vehicle battery pack124may provide a high voltage direct current (DC) output. The traction battery124may be electrically coupled to one or more power electronics modules126(such as a traction inverter). One or more contactors125may isolate the traction battery124from other components via a high-voltage bus127when opened and connect the traction battery124to other components when closed. The power electronics module126is also electrically coupled to the electric machines114and provides the ability to bi-directionally transfer energy between the traction battery124and the electric machines114. For example, a traction battery124may provide a DC voltage while the electric machines114may operate with a three-phase alternating current (AC) to function. The power electronics module126may convert the DC voltage to a three-phase AC current to operate the electric machines114. In a regenerative mode, the power electronics module126may convert the three-phase AC current from the electric machines114acting as generators to the DC voltage compatible with the traction battery124.

The vehicle112may include a variable-voltage converter (VVC) (not shown) electrically coupled between the traction battery124and the power electronics module126. The VVC may be a DC/DC boost converter configured to increase or boost the voltage provided by the traction battery124. By increasing the voltage, current requirements may be decreased leading to a reduction in wiring size for the power electronics module126and the electric machines114. Further, the electric machines114may be operated with better efficiency and lower losses.

In addition to providing energy for propulsion, the traction battery124may provide energy for other vehicle electrical systems. The vehicle112may include a DC/DC converter module128that converts the high voltage DC output of the traction battery124to a low voltage DC supply that is compatible with low-voltage vehicle loads. An output of the DC/DC converter module128may be electrically coupled to an auxiliary battery130(e.g., 12 V battery) for charging the auxiliary battery130. The low-voltage systems having one or more low-voltage loads131may be electrically coupled to the auxiliary battery130. One or more electrical loads132may be coupled to the high-voltage bus127. The electrical loads132may have an associated controller that operates and controls the electrical loads146when appropriate. Examples of electrical loads132may be a fan, an electric heating element, and/or an air-conditioning compressor.

The electrified vehicle112may be configured to recharge the traction battery124from an external power source134. The external power source134may be a connection to an electrical outlet. The external power source134may be electrically coupled to a charger or electric vehicle supply equipment (EVSE)136. The external power source134may be an electrical power distribution network or grid as provided by an electric utility company. The EVSE136may provide circuitry and controls to regulate and manage the transfer of energy between the power source134and the vehicle112. The external power source134may provide DC or AC electric power to the EVSE136. The EVSE136may have a charge connector138for plugging into a charge port140of the vehicle112. The charge port140may be any type of port configured to transfer power from the EVSE136to the vehicle112. The charge port140may be electrically coupled to a charger or on-board power conversion module142. The power conversion module142may condition the power supplied from the EVSE136to provide the proper voltage and current levels to the traction battery124. The power conversion module142may interface with the EVSE136to coordinate the delivery of power to the vehicle112. The EVSE connector138may have pins that mate with corresponding recesses of the charge port140. Alternatively, various components described as being electrically coupled or connected may transfer power using a wireless inductive coupling.

The vehicle112may be further provided with a computing platform150configured to control and coordinative various operations of the vehicle112(to be described in detail below).

The vehicle112may be physically coupled to a trailer160via a trailer coupler162(e.g. a trailer hitch). The trailer160may be provided with energy storage and self-propelling capabilities via various components associated with the trailer160. For instance, the trailer160may be provided with one or more electric machines164mechanically coupled to the trailer wheels168via one or more drive shafts166. In some examples, a trailer transmission (not shown) may be provided between the electric machines164and the drive shaft166and configured to facilitate the drive transmissions therebetween. The electric machines164may be capable of operating as a motor or a generator. The electric machines164may provide propulsion and braking capability when the trailer is in operation. The electric machines164may also act as generators and when the trailer is braking. The trailer160may be further provided with a trailer traction battery170configured to store energy that can be used by the electric machines164. The trailer battery170may provide a high voltage direct current (DC) output. The trailer battery170may be electrically coupled to one or more power electronics module172(such as an inverter). The power electronics module172is also electrically coupled to the electric machines164and provides the ability to bi-directionally transfer energy between the trailer battery170and the electric machines164. For example, a traction battery170may provide a DC voltage while the electric machines164may operate with a three-phase alternating current (AC) to function. The power electronics module172may convert the DC voltage to a three-phase AC current to operate the electric machines164. In a regenerative mode, the power electronics module172may convert the three-phase AC current from the electric machines164acting as generators to the DC voltage compatible with the trailer battery170.

The trailer160may be configured to recharge the trailer battery170from the external power source134via the EVSE136through a charge port174. The charge port174may be electrically coupled to a charger or on-board power conversion module176configured to condition the power supplied from the EVSE136to provide the proper voltage and current levels to the trailer battery170. Operations of the trailer160may be controlled and coordinated via a trailer controlling system180. (To be discussed in detail below.) A high-voltage bus181of the trailer160may be further electrically connected to the high-voltage bus127of the vehicle112via a cable178. The cable178may be integrated with one of the vehicle112and/or the trailer160and disconnect/connect to the other to facilitate the power transaction between the traction battery124and the trailer battery170. In case that the trailer battery170and the traction battery124have different voltages, a DC/DC converter182may be provided to facilitate the voltage conversion. It is noted that although the DC/DC converter is illustrated on the trailer side with reference toFIG.1, the present invention is not limited thereto and the DC/DC converter may be provided on the vehicle side in other examples. The cable178may be further provided with data communication capabilities which enables the computing platform150of the vehicle112to communicate with the trailer controller system180via a wired connection. Additionally or alternatively, the computing platform150and the trailer controlling system180may be further configured to communicate with each other via a wireless connection184to enable various operations.

Referring toFIG.2, an example block topology of a vehicle system200of one embodiment of the present disclosure is illustrated. As illustrated inFIG.2, the computing platform150may include one or more processors206configured to perform instructions, commands, and other routines in support of the processes described herein. For instance, the computing platform150may be configured to execute instructions of vehicle applications208to provide features such as navigation, battery controls, and wireless communications. Such instructions and other data may be maintained in a non-volatile manner using a variety of types of computer-readable storage medium210. The computer-readable medium210(also referred to as a processor-readable medium or storage) includes any non-transitory medium (e.g., tangible medium) that participates in providing instructions or other data that may be read by the processor206of the computing platform150. Computer-executable instructions may be compiled or interpreted from computer programs created using a variety of programming languages and/or technologies, including, without limitation, and either alone or in combination, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, and SQL.

The computing platform150may be provided with various features allowing the vehicle occupants/users to interface with the computing platform150. For example, the computing platform150may receive input from HMI controls212configured to provide for occupant interaction with the vehicle112. As an example, the computing platform150may interface with one or more buttons, switches, knobs, or other HMI controls configured to invoke functions on the computing platform150(e.g., steering wheel audio buttons, a push-to-talk button, instrument panel controls, etc.).

The computing platform150may also drive or otherwise communicate with one or more displays214configured to provide visual output to vehicle occupants by way of a video controller216. In some cases, the display214may be a touch screen further configured to receive user touch input via the video controller216, while in other cases the display214may be a display only, without touch input capabilities. The computing platform150may also drive or otherwise communicate with one or more speakers218configured to provide audio output and input to vehicle occupants by way of an audio controller220.

The computing platform150may also be provided with navigation and route planning features through a navigation controller222configured to calculate navigation routes responsive to user input via, for example, the HMI controls212, and output planned routes and instructions via the speaker218and the display214. Location data that is needed for navigation may be collected from a global navigation satellite system (GNSS) controller224configured to communicate with multiple satellites and calculate the location of the vehicle112. The GNSS controller224may be configured to support various current and/or future global or regional location systems such as global positioning system (GPS), Galileo, Beidou, Global Navigation Satellite System (GLONASS) and the like. Map data used for route planning may be stored in the storage210as a part of the vehicle data226. Navigation software may be stored in the storage210as one the vehicle applications208.

As discussed above, the computing platform150may be configured to wirelessly communicate with the trailer controlling system180via the wireless connection184and/or a wired connection162. A wireless transceiver232may be in communication with a Wi-Fi controller234, a Bluetooth controller236, a radio-frequency identification (RFID) controller238, a near-field communication (NFC) controller240, and other controllers such as a Zigbee transceiver, an IrDA transceiver, an ultra-wide band (UWB) controller (not shown), and be configured to communicate with a compatible wireless transceiver242of the trailer controlling system180.

The trailer controlling system180may be provided with a processor244configured to perform instructions, commands, and other routines in support of the processes such as wireless communication, and trailer powertrain control or the like. For instance, the trailer controlling system180may be provided with a GNSS controller248. The trailer controlling system180may be provided with the wireless transceiver242in communication with a Wi-Fi controller250, a Bluetooth controller252, a RFID controller254, an NFC controller256, and other controllers (not shown), configured to communicate with the wireless transceiver232of the computing platform150. The trailer controlling system180may be further provided with a non-volatile storage258to store various trailer application260.

The computing platform150may be further configured to communicate with various components of the vehicle112via one or more in-vehicle networks266. The in-vehicle network266may include, but is not limited to, one or more of a controller area network (CAN), an Ethernet network, and a media-oriented system transport (MOST), as some examples. Furthermore, the in-vehicle network266, or portions of the in-vehicle network266, may be a wireless network accomplished via Bluetooth low-energy (BLE), Wi-Fi, UWB, or the like.

The computing platform150may be configured to communicate with various electronic control units (ECUs)268of the vehicle112configured to perform various operations via the in-vehicle network266. The computing platform150may be configured to communicate with a TCU270configured to control telecommunication between vehicle112and a wireless network272through a wireless connection274using a modem276. The wireless connection274may be in the form of various communication networks, for example, a cellular network. Through the wireless network272, the vehicle may access one or more servers278to access various content for various purposes. It is noted that the terms wireless network and server are used as general terms in the present disclosure and may include any computing network involving carriers, router, computers, controllers, circuitry or the like configured to store data and perform data processing functions and facilitate communication between various entities. The ECUs268may include a powertrain control module (PCM)280configured to monitor and operate the power train of the vehicle112. In the present example, the PCM280may be further configured to control and coordinate the powertrain operations of both the vehicle112and the trailer160individually or in combination with the computing platform150. The ECUs268may further include an autonomous driving controller (ADC)282configured to control an autonomous driving feature of the vehicle112. Driving instructions may be received remotely from the server278. The ADC282may be configured to perform the autonomous driving features using the driving instructions combined with navigation instructions from the navigation controller222. The ADC282may be configured to adjust the driving instructions adapted for various driving conditions. For instance, the ADC282may adjust the driving instructions depending on whether the trailer160is connected to the vehicle112. If the trailer160is connected, the ADC282may avoid instructions involving heavy acceleration/brake or tight turn or the like. The ECUs268may be provided with or connected to one or more sensors284providing signals related to the operation of the specific ECU268. For instance, the sensors284may include an ambient temperature sensor configured to measure the ambient temperature of the vehicle112. The sensors284may further include one or more engine/coolant temperature sensors configured to measure the temperature of the engine/coolant and provide such data to the PCM280. The sensors284may further include one or more battery temperature sensors configured to measure the temperature of one or more cells of the traction battery124. The sensors284may further include one or more weight sensors to measure the weight/load of the vehicle112. In addition, the trailer160may be provided with various trailer sensors286configured to provide sensor data to the trailer controller system180as well as to the computing platform150. For instance, the trailer sensors286may include a temperature sensor (not shown) to measure the temperature of one or more cells of the trailer battery170. The trailer temperature may be sent to the computing platform150and/or the PCM280to facilitate the powertrain control and coordination between the vehicle112and the trailer160. The trailer sensors286may further include one or more weight sensors configured to measure the weight/load of the trailer160.

Referring toFIG.3, an example flow diagram of a process300for balancing charges between the traction battery124and the trailer battery170is illustrated. One of the purposes of the battery balancing is to prevent battery and/or motor overheating caused by excessive use of a single battery and motor. With continuing reference toFIGS.1and2, the process300may be implemented via one or more components of the vehicle112and the trailer160. For instance, the process300may be individually or collectively implemented via the computing platform150, the PCM280, and/or the trailer controlling system180. For simplicity purposes, the following description will be made with reference to the computing platform150. At operation302, responsive to detecting the vehicle112has been connected to the trailer160, the computing platform150measures the SOC of both the traction battery124and the trailer battery170to determine a total amount of charge in the batteries combined. The capacity for the traction battery124and for the trailer battery170may be different and the SOC as measured from both batteries may be used as a reference to determine how much charge each battery currently has specifically. At operation304, the computing platform150measures the weight of the vehicle112and trailer via one or more respective weight sensors284,286. At operation306, the computing platform150plans a navigation route via the navigation controller222. The route destination may be manually input to the computing platform150by a vehicle user via the HMI controls212. Alternatively, the destination may be automatically generated by the computing platform150using vehicle data226such as a user calendar or the like. Alternatively, the destination may be received from the server278via the TCU270.

At operation308, the computing platform150determines a desired charge distribution between the traction battery124and the trailer battery170based on the total charge, the weight and the planned route. In general, it may be preferrable to distribute the charges between the traction battery124and the trailer battery170to allow a relatively even motor propulsion such that the heat generated by the respective motors and batteries are balanced. The desired charge distribution may vary depending on one or more of the above factors. For instance, responsive to a heavily loaded trailer, it may be desired to distribute more charge to the trailer battery170to use the trailer motor164more often for propulsion. At operation310, the computing platform150verifies if one of the batteries currently has less than the respective desired charge. In general, having more than the desired charge is acceptable. What is undesired is one of the batteries having insufficient charge to propel the respective motor as planned. If the answer for operation310is yes indicative of both batteries having the sufficient charge, the process proceeds to operation312and there may be no need to balance the charge between the traction battery124and the trailer battery170. Otherwise, if the answer is no indicative of a charge transfer being needed, the process proceeds to operation314and the computing platform150identifies the one of the batteries to be charged as a recipient and the other one of the batteries to donate the charge as a donor. The computing platform150further determines the amount of charge to be transferred from the donor to the recipient such that the recipient battery reaches the desired charge distribution. At operation316, the computing platform150further verifies if the traction battery124and the trailer battery170are connected via the power cable178. If the answer is yes, the process proceeds to operation318and the computing platform150coordinates the charge transfer via the cable178by transferring the calculated amount of the charge from the donor to the recipient. Otherwise, if the traction battery124and the trailer battery170are not electrically connected, the process proceeds to operation320and the computing platform150coordinates the charge transfer by instructing the vehicle112and the trailer160to propel primarily using the electric power from the donor, and to primarily generate the regenerative braking power to charge the recipient as the vehicle drives to balance the electric charge.

Referring toFIG.4, an example flow diagram of a process400for charging the trailer160is illustrated. With continuing reference toFIGS.1-3, responsive to detecting a compatible charging station / EVSE136for the trailer160at operation402, the computing platform150determines an amount of charge to be transferred from the trailer battery170to the traction battery124. In general, since the trailer may be charged at the EVSE136, it may be desired to leave as little charge as possible at the trailer160when the vehicle112and the trailer160arrives at the EVSE136. Therefore, at operation404, the computing platform150may determine a desired charge distribution using the EVSE136as the destination similar to the operations306and308discussed with reference toFIG.3, and calculate the amount of charge that may be transferred from the trailer battery170to the traction battery124before arriving at the destination. Alternatively, there may be situations when the current charge of the trailer160is insufficient to reach the destination. In these cases, the computing platform150may determine the amount of charge to be transferred from the vehicle112to the trailer160. At operation406, the computing platform150transfers the charge from the trailer battery170to the traction battery124while the vehicle is driving to the destination. At operation408, once arrived at the EVSE136, the vehicle112may be disconnected from the trailer leaving the trailer connected to the EVSE136alone. Since the extra charge has been transferred to the traction battery124, at operation410, the vehicle112may have more flexibility to drive elsewhere while waiting for the trailer160to be charged. At operation412, once the vehicle112returns to the EVSE136, the vehicle112may be reconnected to the trailer412. In one example, the trailer160may send a message to the vehicle112via the wireless network272to inform the vehicle112that the charging process is complete (or about to complete). At operation414, the computing platform150performs the charge balance process as illustrated with reference toFIG.3before reaching the next destination.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure.