Predictive dynamic speed control for an electrified vehicle travelling along a steep grade route

Abstract

A vehicle system includes a powertrain including a prime mover system including an electric power system including an energy storage system (ESS), power electronics operably coupled with the ESS, and an electric machine operably coupled with the power electronics; one or more ground engaging wheels operably coupled with the prime mover system; and an electronic control system in operable communication with the prime mover system, the electronic control system configured to determine a pre-downhill target vehicle speed, a pre-downhill electric power system target state, and a downhill vehicle speed target prior to reaching a downhill road segment, control the vehicle system to achieve the pre-downhill target vehicle speed and the pre-downhill electric power system target state prior to reaching the downhill road segment or upon reaching the downhill road segment, and operate the electric power system to perform electric braking during the downhill road segment to control vehicle speed according to the downhill vehicle speed target.

Description

Technical Field

[0001] This disclosure relates to vehicle control systems, and more specifically, but not exclusively, to predictive dynamic speed control for electrified vehicles traveling along steep incline routes, and related devices, processes, systems, and techniques. Background Technology

[0002] Existing methods for vehicle speed control have many drawbacks and limitations, including those related to controlling vehicles traveling along steep inclines, such as efficiency issues and premature wear, overheating, and other problems caused by excessive use of the base brakes. There remains a significant need for the unique devices, methods, and systems disclosed herein.

[0003] Disclosure of illustrative embodiments To clearly, concisely, and accurately describe the illustrative embodiments of this disclosure, their preparation and use, and to enable the practice, preparation, and use of these illustrative embodiments, reference will now be made to certain exemplary embodiments (including those illustrated in the accompanying drawings), and these embodiments will be described using specific language. However, it should be understood that this does not limit the scope of the invention, and the invention includes and protects such changes, modifications, and further applications of the exemplary embodiments that can be conceived by those skilled in the art. Summary of the Invention

[0004] One embodiment is a system including unique predictive dynamic speed control for an electrified vehicle traveling along a steep incline. Another embodiment is a method including unique predictive dynamic speed control for an electrified vehicle traveling along a steep incline. Yet another embodiment is an apparatus including unique predictive dynamic speed control for an electrified vehicle traveling along a steep incline. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and accompanying drawings. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of a vehicle that has a control system for controlling the vehicle's speed.

[0006] Figures 2A to 2D It is a schematic diagram illustrating certain aspects of vehicle operation on a vehicle route.

[0007] Figures 3A to 3C It is a schematic diagram illustrating certain aspects of vehicle operation on a vehicle route.

[0008] Figure 4 This is a flowchart illustrating an example process for controlling a vehicle.

[0009] Figure 5 It is a diagram illustrating certain aspects of the control architecture used to control various operational aspects of a vehicle.

[0010] Figure 6 It is a schematic diagram illustrating certain aspects of vehicle operation on a vehicle route.

[0011] Figure 7 It is a schematic diagram illustrating certain aspects of vehicle operation on a vehicle route.

[0012] Figures 8A to 8C It is a schematic diagram depicting certain aspects of the architecture of a battery-electric powertrain.

[0013] Figures 9A to 9C This is a schematic diagram depicting certain aspects of the series hybrid powertrain architecture.

[0014] Figures 10A to 10C It is a schematic diagram depicting certain aspects of the fuel cell powertrain architecture.

[0015] Figures 11A to 11F This is a schematic diagram depicting certain aspects of the architecture of a parallel hybrid power system.

[0016] Figures 12A to 12B This is a schematic diagram depicting certain aspects of the architecture of a series-parallel hybrid power system.

[0017] Figure 13 It is a schematic diagram depicting certain aspects of the parallel powertrain architecture that runs through the road. Detailed Implementation

[0018] refer to Figure 1 The illustration shows a schematic diagram of an example vehicle 100 including a powertrain 102 integrated within the vehicle 100. In the illustrated embodiment, the vehicle 100 and the powertrain 102 are configured and provided in an electrified manner, wherein the powertrain 102 includes a prime mover system 103 comprising an internal combustion engine 104 and an electrical system 117 comprising electric motors 151 (e.g., one or more traction motors (TM)), power electronics 153 (e.g., inverters and / or other types of power converters, buses, and regulators) operatively coupled to each other, and an energy storage system (ESS) 155. In the illustrated example, the ESS 155 includes a battery pack. In other embodiments, the ESS 155 may additionally or alternatively include one or more supercapacitors, one or more supercapacitors, one or more fuel cells, or one or more other energy storage components as would be conceived by those skilled in the art based on the benefits and teachings of this disclosure.

[0019] In the example shown, vehicle 100, powertrain 102, and prime mover system 103 are configured and arranged as a parallel hybrid system, in which internal combustion engine 104 and electric motor 151 are configured to selectively output torque to propel vehicle 100. Other embodiments consider other types of electrification architectures, including, for example, battery electric powertrain architectures, series hybrid powertrain architectures, fuel cell powertrain architectures, other types of parallel hybrid powertrain architectures, series-parallel electric powertrain architectures, road-connected parallel powertrain architectures, and other electrified powertrain architectures.

[0020] The powertrain 102 also includes a transmission 106 connected to the prime mover 104 for regulating the output torque of the prime mover system 103 and transmitting that output torque to the drivetrain 107, which includes a drive shaft 108. In the illustrated embodiment, the transmission 106 may be disengagedly connected to the engine crankshaft 105 via a clutch 109.

[0021] In other embodiments, transmission 106 may be disengagedly connected to engine crankshaft 105, and engagement and disengagement may be achieved by operating a main clutch located at the front of the transmission, by operating the transmission to shift to neutral, or by other clutches and / or gear mechanisms. Various embodiments envision transmission 106 as an automatic transmission, automatic-manual transmission, manual transmission, or any other suitable transmission with a disconnection device 111 operable to selectively engage and disengage engine 104 from drivetrain 107. It should be understood that some embodiments (such as battery electric vehicle (BEV) powertrains or fuel cell powertrains) may omit transmission 106. It should also be understood that clutches according to this disclosure may include a main clutch, a clutch within the transmission, a clutch within the electric drive axle, a clutch within the drivetrain, or clutches at other locations within the powertrain system as would be conceived by those skilled in the art based on the benefits and teachings of this disclosure.

[0022] In the rear-wheel drive configuration of the illustrated vehicle 100, the drivetrain 107 of the powertrain 102 includes a final drive 110 having a rear differential 112 connecting the drive shaft 108 to the rear axles 114a, 114b. It is contemplated that components of the powertrain 102 may be located at various locations throughout the vehicle 100. In a non-limiting example of the vehicle 100 with a front-wheel drive configuration, the transmission 106 may be a variable-speed drive axle, and the final drive 110 may be located at the front of the vehicle 100, connecting the front axles 116a and 116b to the engine 104 via the variable-speed drive axle. It is also contemplated that in some embodiments, the vehicle 100 may be in an all-wheel drive configuration.

[0023] In the illustrated embodiment, vehicle 100 includes two front wheels 122a and 122b respectively mounted to front axles 116a and 116b. Vehicle 100 also includes two rear wheels 126a and 126b respectively mounted to rear axles 114a and 114b. It is conceivable that vehicle 100 may have a... Figure 1 The vehicle 100 may have more or fewer wheels. The vehicle 100 also includes basic brakes 124a, 124b, 127a, 127b (sometimes referred to as service brakes) to automatically and mechanically decelerate one or more wheels 122a, 122b, 126a, 126b, respectively, upon application of brake pedal 128 and / or in response to one or more vehicle speed control outputs. The vehicle 100 also includes an engine braking system 129 operable to decelerate the prime mover system 103 and the vehicle 100 without friction braking, for example, by compression-release braking, exhaust braking, etc. The vehicle 100 may also include various components not shown, such as a fuel system including a fuel tank, front differential, suspension, engine intake system, and exhaust system (which may include an exhaust aftertreatment system), to name just a few.

[0024] Vehicle 100 includes an electronic or engine control unit (ECU) 130 (sometimes referred to as an electronic or engine control module (ECM), etc.) for regulating and controlling the operation of engine 104. Accelerator pedal 145 and / or other throttle control mechanisms can be connected to ECU 130 to initiate fuel supply by the operator. A transmission control unit (TCU) 140 is illustrated in vehicle 100 for regulating and controlling the operation of transmission 106. ECU 130 and TCU 140 are each operatively communicatively connected to multiple vehicle sensors (not shown) in vehicle 100 to receive and transmit operating conditions of vehicle 100, such as temperature conditions, pressure conditions, speed conditions, fuel conditions, flow conditions to and from the engine, terrain conditions, weather conditions, GPS data, and vehicle mass. It is conceivable that ECU 130 and TCU 140 may be integrated within engine 104 and transmission 106, respectively.

[0025] Vehicle 100 also includes a Vehicle Speed ​​Management (VSM) controller or control unit 150, which can be used to control the operations described herein and / or to provide intermediate control for the regulation and control of the powertrain 102 in vehicle 100. VSM control unit 150 is operatively communicative with ECU 130 and TCU 140. In some embodiments, a portion or all of VSM control unit 150 may be integrated within ECU 130 or TCU 140 or other vehicle control units. In still embodiments, at least VSM control unit 150 communicates with ECU 130 and / or TCU 140 via a data link provided by a wired or wireless connection, such that the output of VSM control unit 150, independent of ECU 130 and / or TCU 140, can be provided to ECU 130 and / or TCU 140.

[0026] The VSM control unit 150 can also operatively communicate with one or more of a plurality of vehicle sensors in the vehicle 100 to receive and transmit conditions of the vehicle 100, such as temperature and pressure conditions, route conditions, road curvature, terrain conditions, speed conditions, and weather conditions. It is conceivable that, in addition to or as an alternative to the plurality of vehicle sensors, at least a portion of the conditional and / or measurement inputs used by the VSM control unit 150 for interpreting signals may be received from the ECU 130 and / or TCU 140. Furthermore, the VSM control unit 150 may include one or more processors or controllers, such as an idle coasting management (ICM) controller, a towing controller, etc.

[0027] VSM control unit 150 and / or ECU 130 and TCU 140 include stored data values, constants, and functions, as well as operating instructions stored on, for example, a computer-readable medium. Any operation of the example processes described herein may be performed at least in part by VSM control unit 150. In some embodiments, VSM control unit 150 includes one or more controllers configured to functionally perform controller operations. Further details of certain example embodiments of controller operation will be discussed below. The operations shown are to be understood as exemplary only, and operations may be combined or divided, added or removed, and reordered wholly or partially, unless expressly stated to the contrary herein.

[0028] Some of the operations described herein include operations for interpreting or determining one or more parameters. As used herein, interpretation or determination includes receiving a value by any method including receiving the value from at least a data link or network communication, receiving an electronic signal indicating the value (e.g., a voltage, frequency, current, or pulse width modulation (PWM) signal), receiving a software parameter indicating the value, reading the value from a memory location on a computer-readable medium, receiving a value as a runtime parameter by any means known in the art, and / or by receiving a value that the interpreted or determined parameter can be calculated, and / or by referring to a default value that is interpreted or determined as a parameter value.

[0029] ECU 130, TCU 140, and VSM control unit 150 are example components of an integrated circuit-based electronic control system (ECS) that can be configured to control various operational aspects of vehicle 100 and powertrain 102, as described in further detail herein. The ECS according to this disclosure can be implemented in various forms and can include multiple different elements and configurations of elements. In some preferred forms, the ECS may include one or more microprocessor-based or microcontroller-based electronic control units (sometimes referred to as electronic control modules). The ECS according to this disclosure may be provided in the form of having a single processing or computing unit, or in the form of including multiple processing or computing units capable of operatively coupling; and may include digital circuitry, analog circuitry, or a hybrid combination of both. The integrated circuits and / or any of the components of the processor / controller or other parts 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 various circuits or functional parts that a person skilled in the art would conceive of for providing and performing the communication and control aspects disclosed herein.

[0030] An example embodiment of the VSM control unit 150 is configured to dynamically adjust the vehicle speed toward a target speed before the vehicle reaches a downhill section of the route. In the example embodiment, the vehicle speed can be dynamically adjusted toward a target speed before or upon reaching a downhill section of the route. The VSM control unit 150 can use look-ahead data and vehicle parameters such as vehicle mass to determine or predict the vehicle's terminal speed, transmission gear (where applicable, i.e., when a transmission is present in the vehicle), and the target state of the electrical system before the downhill (where applicable, i.e., when the electrical system is part of the vehicle's prime mover system). The terminal speed, transmission gear (where applicable), and target electric system state (where applicable) may be determined based on any one or more of the foregoing conditions: (i) the vehicle's terminal speed, transmission gear (where applicable), and target electric system state (where applicable) result in the vehicle safely traversing the downhill section based on road slope or gradient taking into account vehicle operating parameters such as vehicle mass, rear axle ratio, tire rolling radius, and / or other parameters affecting the vehicle's ability to traverse the downhill section; (ii) the terminal speed, transmission gear (where applicable), and target electric system state (where applicable) may be determined based on the condition that the powertrain reducer has sufficient deceleration power to compensate for road gradient power after taking into account all losses (including aerodynamic, rolling friction, and powertrain losses); and (iii) the determination of the terminal speed, transmission gear (where applicable), and target electric system state (where applicable) may or may not involve driver intervention or control of the vehicle. The VSM control unit 150 can determine the target speed, transmission gear (where applicable), and target power system state (where applicable) based on the following rules: (iv) the target speed is less than both the terminal speed and the speed limit; (v) the target gear is less than both the terminal gear and the highest transmission gear allowed under the speed limit (where applicable); and (vi) the target speed and gear are the highest of the possible values ​​satisfying conditions (iv), (v), and conditions (i), (ii), and (iii) used to define the terminal speed and transmission gear (where applicable). The VSM control unit 150 can also be configured to dynamically adjust the vehicle speed towards the target speed, in addition to dynamically adjusting the vehicle speed towards the target speed before the vehicle is on a downhill section of the route, while the vehicle is traveling along a downhill section of the route. The VSM control unit 150 is also configured to control the vehicle speed to not exceed the downhill vehicle speed target during the downhill section.

[0031] Another example embodiment of the VSM control unit 150 can be configured to dynamically adjust the vehicle speed to a gliding target speed on a portion of a downhill route segment. In the example embodiment, when the vehicle reaches a portion of the downhill route segment, the VSM control unit 150 can control the vehicle speed to accelerate toward the gliding target speed (if necessary, because the current vehicle speed is below the gliding target speed). For example, the VSM control unit 150 can use look-ahead data to determine the gliding target speed in response to speed limits for that portion of the downhill route segment (e.g., a first indicated speed limit) and speed limits for the route segment preceding or ahead of that portion of the downhill route segment (e.g., a second indicated speed limit).

[0032] It should be understood that a given downhill route segment according to this disclosure may be preceded by an uphill route segment leading to a local apex, a route segment that is substantially flat or has zero gradient, and / or a downhill route segment with a gradient different from the given downhill route segment. Similarly, a downhill vehicle speed target according to this disclosure may include a vehicle speed target associated with a downhill route segment that is preceded by any one or more preceding road segments of the aforementioned types. Downhill vehicle speed targets according to this disclosure may include speed targets based at least in part on: marked speed limits, temporary speed limits (e.g., construction zone speed limits or speed limits based on driver intervention), speed limits based on road conditions (e.g., road curvature, icy conditions, wet conditions, or other road conditions), terminal speeds calculated or determined for a vehicle for a given set of downhill operating conditions (e.g., environmental parameters and conditions, vehicle parameters and conditions, such as road slope or gradient given vehicle operating parameters, such as vehicle mass, rear axle ratio, tire rolling radius, and / or other parameters affecting the vehicle's ability to traverse a downhill route segment) (i.e., physically based terminal speeds), speed limits based on operator instructions or preferences or fleet manager instructions or preferences, vehicle speeds at the end of a downhill route segment or at predetermined points along the downhill route segment, and / or other standards or considerations. Similarly, downhill target vehicle speeds according to this disclosure may include target vehicle speeds associated with any one or more of the aforementioned types of road segments preceding the downhill route segment.

[0033] It is conceivable that the forward-looking data used to determine the terminal speed may include data collected using a variety of technologies, including, for example, terrain data, environmental conditions, road surface conditions, road curvature, proximity or position of other vehicles, distance or gap from one or more other vehicles, speed of one or more other vehicles, route conditions, upcoming gradient or road slope conditions, GPS data, mapping data, inputs from one or more other vehicles or forward-looking radar systems, and / or one or more models of vehicle 100, including estimated mass, aerodynamic drag, rear axle ratio, tire rolling radius, and other conditions associated with vehicle 100. Terrain data may be collected from slope sensors, such as inclinometers or computer models, configured to determine or estimate slope information based on maps or Geographic Information System (GIS) datasets, which may be mounted on the vehicle or received via transmission from a remote location or a combination of these technologies.

[0034] See Figures 2A to 2D The illustrations show diagrams 200a, 200b, 200c, and 200d depicting vehicles 100 at multiple locations along route 202, which includes a downhill section 204. Figure 2A At the indicated location, vehicle 100 travels along a section of route 202 preceding downhill route segment 204. At the indicated location (or one or more additional or alternative locations preceding the downhill route segment), the electronic control system of vehicle 100 can obtain forward-looking data including at least one of future road gradient and speed limit information for route 202. The forward-looking data can be obtained via a wireless communication link from one or more in-vehicle systems, one or more external systems, or a combination thereof. In some embodiments, for example, the electronic control system of vehicle 100 can identify the downhill route segment in response to one or more GPS signals and in-vehicle map information.

[0035] The electronic control system of vehicle 100 can use at least one of forward-looking data or future road gradient and speed limit information to determine whether vehicle 100 is approaching downhill section 204, and in response, determine the target speed before descent, the target transmission gear before descent (where applicable), the target electric system state before descent (where applicable), the target speed on the downhill slope, the target transmission gear on the downhill slope (where applicable), and the target electric system state on the downhill slope (where applicable). The target speed before descent, the target transmission gear before descent (where applicable), the target electric system state before descent (where applicable), the target speed on the downhill slope, the target transmission gear on the downhill slope (where applicable), and the target electric system state on the downhill slope (where applicable) can be determined according to an objective function optimization configured to minimize fuel consumption (or energy consumption, such as in the case of an electric vehicle, a hybrid electric vehicle, or a fuel cell vehicle) constrained by vehicle speed limits and potentially subject to one or more additional constraints (e.g., minimum vehicle speed, maximum travel time, target deceleration rate, or other constraints conceivable by those skilled in the art based on the teachings and inspirations of this disclosure). Vehicle speed limit constraints can be indicated or legal speed limits obtained from one or more onboard systems, one or more off-board systems via a wireless communication link, or a combination thereof. Vehicle speed limit constraints can be obtained from one or more cameras to detect indicated, legal speeds or construction zone speed limits.

[0036] The electronic control system of vehicle 100 is also configured and operable to control vehicle speed to achieve a target speed before descent, control the vehicle transmission to a target gear before descent (where applicable), and control the electrical system to provide a target state of electrical system before descent (where applicable) before or at the start of descent section 204. The target speed before descent, the target gear before descent (where applicable), and the target state of electrical system before descent (where applicable) can be used by vehicle 100 during a portion of descent section 204 or during substantially all of descent section 204, or can be changed based on one or more target descent speeds and / or one or more target gear before descent (where applicable). The target speed before descent, the target transmission gear before descent (where applicable), and the target state of the electric system before descent (where applicable) can be selected to provide an initial vehicle speed lower than the target descent vehicle speed, a transmission gear (where applicable) predicted to allow vehicle 100 to accelerate to the target descent vehicle speed at a predetermined location along the descent segment, and the power absorption capacity of the electric system (where applicable) predicted to allow the use of regenerative braking or other electric braking (e.g., releasing power from an electric motor via a braking resistor or a mechanical braking load such as an engine equipped with an engine brake) to maintain the target descent vehicle speed. Fuel and / or energy consumption optimization can allow the vehicle to... Figure 2A The position of vehicle 100 depicted in the image and Figure 2B The vehicle coasts some or all of the distance between the locations depicted, and then accelerates along downhill section 204 until it reaches the downhill vehicle speed target. Fuel and / or energy consumption optimization can allow the vehicle to... Figure 2A The location and Figure 2D The energy storage system is supplemented between or after the locations depicted (where applicable).

[0037] exist Figure 2B At the indicated location, vehicle 100 has reached apex 201 at the beginning of downhill section 204. Upon reaching apex 201 or prior to reaching apex 201, preferably vehicle 100's speed has been controlled to achieve a target speed before the descent, preferably the transmission has been controlled to engage the target gear before the descent (where applicable), and preferably the electrical system has been controlled to provide the target electrical system state before the descent (where applicable). Vehicle 100 may begin descending along downhill section 204, at least initially at the target gear before the descent (where applicable), at the target electrical system state before the descent, or approximately at the target speed before the descent.

[0038] exist Figure 2CAt the location shown, vehicle 100 is traveling along a downhill section 204. The electronic control system of vehicle 100 is configured and operable to maintain the speed of vehicle 100 at or below the downhill vehicle speed target. As vehicle 100 travels along downhill section 204, the electronic control system of vehicle 100 can control one or more components of the powertrain to perform at least one of reducing the vehicle's speed and maintaining the vehicle's speed to conform to the downhill vehicle speed target. The electronic control system can, for example, engage and operate one or more of the powertrain reducer, transmission downshift (where applicable), and vehicle base brakes to maintain the speed of vehicle 100 at or below the downhill vehicle speed target. It should be understood that powertrain reducers according to this disclosure may include, for example, engine brakes such as compression release brakes or exhaust brakes, hydraulic powertrain reducers, powertrain / vehicle accessory and electromagnetic powertrain reducers, electric brakes based on electric motors (such as operation of electric motors, power electronics and energy storage systems in regenerative braking mode, operation of electric motors and braking resistors for dissipating power, or operation of electric motors and mechanical loads (such as engines) in engine braking mode and coupled to electric motors), or other powertrain reducers as would be conceived by those skilled in the art based on the benefits and teachings of this disclosure.

[0039] At one or more points during the downhill section, the electronic control system can control the operation of the powertrain reducer to help reduce the vehicle's speed and maintain at least one of the vehicle's speed without applying the base brakes. Regenerative braking can be prioritized as a first-order operation for maintaining or reducing the vehicle's speed along the downhill section 204.

[0040] At one or more points during the downhill section, the electronic control system can control the operation of the powertrain reducer to help reduce the vehicle speed and maintain at least one of the vehicle speed without applying the base brakes. Other electric braking operations (e.g., via a braking resistor) can be prioritized as a second-order operation for maintaining or reducing the vehicle speed along the downhill section 204. Alternatively, other electric braking operations can be prioritized as a first-order operation for maintaining or reducing the vehicle speed along the downhill section 204.

[0041] At one or more points during the downhill section, the electronic control system can control the operation of the powertrain reducer to help reduce the vehicle speed and maintain at least one of the vehicle speed without applying the base brakes. Operation of the engine brakes can be prioritized as a third-order operation for maintaining or reducing the vehicle speed along the downhill section 204. Alternatively, engine braking can be prioritized as a first-order or second-order operation for maintaining or reducing the vehicle speed along the downhill section 204.

[0042] In embodiments including a transmission, at one or more points during a downhill section, the electronic control system may downshift the transmission to a lower gear to help reduce vehicle speed and maintain vehicle speed at least one of the following:

[0043] In embodiments including a transmission, at one or more points during a downhill section, the electronic control system may operate a base brake during the downhill section and during a downshift of the transmission to help reduce vehicle speed and maintain vehicle speed at least one of the following:

[0044] In some embodiments, the priority order among operational, regenerative braking, other electric braking, engine braking, transmission shifting, and basic braking can follow various sequences or can be dynamically adjusted based on the real-world scenario.

[0045] This disclosure considers several braking techniques that can be used to reduce vehicle speed to a target vehicle speed before descending a slope and / or to reduce or maintain vehicle speed at or below the target vehicle speed on the downhill slope. Some example braking techniques involve operating a base brake to reduce vehicle speed until the vehicle is able to downshift. Some example braking techniques involve operating a base brake during a transmission shift (where applicable) to limit or prevent positive vehicle / engine acceleration or to provide negative vehicle / engine acceleration. Some example braking techniques involve operating a base brake and subsequently monitoring vehicle / engine speed to determine whether to perform additional operations on the base brake. Some example braking techniques involve modulating deceleration power in response to local changes in road gradient. Some example braking techniques involve operating a base brake to avoid or mitigate a downshift event. Some example braking operations include: before a downhill section, first controlling one or more components of the powertrain to provide at least one of reducing vehicle speed and maintaining vehicle speed without applying the base brake, and in response to determining that the first control cannot effectively achieve the target vehicle speed before the downhill section, operating the base brake to reduce vehicle speed and maintain vehicle speed.

[0046] When approaching or during the period of maximum powertrain deceleration, intermittent braking can be used. Intermittent braking can be combined with gear shifting. While continuing to apply powertrain deceleration, intermittent braking can be performed to reduce the vehicle speed below a target level. This can be used to test for temporary changes in road gradient, allowing the vehicle speed to be maintained without a full gear shift.

[0047] This disclosure considers several electric motor operations that can be used to reduce the vehicle speed to a target vehicle speed before descending a slope and / or to reduce or maintain the vehicle speed at or below the target vehicle speed on the downhill slope. Some example electric motor operations involve using the electric system of the prime mover system to drive the vehicle, either wholly or partially, thereby increasing the capacity of the electric system to absorb electricity via electric braking. Some example electric motor operations involve operating the electric system of the prime mover system to perform regenerative braking or other electric braking (e.g., releasing electricity from the electric motor through a braking resistor or a mechanical braking load, such as an engine equipped with engine brakes), thereby maintaining the target downhill vehicle speed.

[0048] exist Figure 2DAt the location shown, vehicle 100 is traveling near the end of downhill section 204. The electronic control system of vehicle 100 can use look-ahead data to determine whether vehicle 100 is approaching the end of downhill section 204, and in response to such determination, control vehicle 100 to perform hill descent control (HRO) to accelerate vehicle 100 on a portion of downhill section 204. When vehicle 100 reaches that portion of downhill section 204, the HRO operation can control the vehicle speed to accelerate towards a target descent speed. The electronic control system can be configured to determine the target descent speed of the vehicle on a portion of the downhill section, and when the vehicle reaches a predetermined position or portion of the downhill section, control the vehicle to allow acceleration towards the target descent speed in response to gravity. The electronic control system of vehicle 100 can determine the target descent speed in response to one of a first indicated speed limit for that portion of the downhill section and a second indicated speed limit for the preceding section of the downhill section.

[0049] Embodiments including prime mover systems with electric power systems can utilize various technologies to perform HRO operations. For example, parallel hybrid power systems (e.g., Figure 1 The power system 102, Figure 11A The power system 1101, Figure 11B The power system 1102, Figure 11C The power system 1103, Figure 11D The power system 1104, Figure 11E The power system 1105 or Figure 11F The powertrain 1106 can utilize regenerative braking or other electric braking in combination with engine reversing, coasting in neutral, or coasting with the engine off to replace or supplement engine braking. Series hybrid powertrains (e.g., Figure 9A The power system 901, Figure 9B The power system 902 or Figure 9C The power system 903) or series-parallel power system (e.g., Figure 12A The power system 1201 or Figure 12B The powertrain 1202 may include a clutch between the engine and the generator and is operable to perform coasting with the clutch disengaged. In some operating scenarios, such a system can perform electric braking with the clutch disengaged. Series hybrid powertrains (e.g., Figure 9A The power system 901, Figure 9B The power system 902 or Figure 9C The powertrain of the 903), the powertrain of the battery electric vehicle (BEV) (for example, Figure 8A The power system 801, Figure 8B The power system 802 or Figure 8CThe powertrain 803) and fuel cell powertrain (e.g., Figure 10A The power system 1001, Figure 10B The power system 1002 or Figure 10C The power system 1003 can control the electric motor to reduce the amount of regenerative braking or other electric braking. Series-parallel power systems (e.g., Figure 12A The power system 1201 or Figure 12B The power system 1202) and the parallel power system that runs through the road (e.g., Figure 13 The power system 1301 can utilize any of the operations described above.

[0050] Figures 2A to 2D The illustration depicts an example of Predictive Dynamic Speed ​​Control (PDSC), which can be implemented and executed by the electronic control system of vehicle 100. PDSC may include several additional and / or alternative aspects. In one aspect, PDSC may limit the speed of vehicle 100 to a marked speed limit on a substantially flat road segment. For example, if the vehicle route remains substantially flat but the marked speed limit decreases, PDSC may control the vehicle speed to gradually decrease to the new marked speed limit in a manner similar to the illustration of downhill driving. PDSC may operate in cruise control and accelerator-based driving. In cruise control operation, PDSC may reduce the vehicle speed from the nominal isochronous cruise control speed to a safe descent speed. In accelerator-based operation, PDSC may prevent the driver from accelerating back to the marked speed limit above the safe descent speed.

[0051] On the other hand, when the vehicle approaches a lower indicated speed limit and the driver does not take action to reduce the vehicle speed, the PDSC can activate and apply a powertrain decelerator and / or downshift to reduce the vehicle speed to the new indicated speed limit. After the new indicated speed limit is reached, the PDSC can become inactive and return full control of the vehicle to the driver if the vehicle is not on a downhill slope. In another embodiment, the PDSC can remain active after the new indicated speed limit is reached and always force the vehicle speed to comply with the indicated speed limit.

[0052] On the other hand, when a vehicle approaches a downhill slope and the driver does not take any action but attempts to increase the vehicle speed to the indicated speed limit, PDSC can apply electric braking and / or activate and apply engine braking and / or downshift to reduce the vehicle speed and gear to the desired value, thereby achieving a safe descent. Throughout the downhill descent, PDSC can remain active to effectively maintain the vehicle speed at or below the downhill speed target.

[0053] On the other hand, the PDSC can determine when it should begin gradually downshifting / downgrading and / or preparing the electric system state to prepare the vehicle before the downhill section, and when to initiate hill descent rear-end collision (HRO) operations. The PDSC can determine one or more predicted speeds as vectors corresponding to a predetermined look-ahead horizon (e.g., a 5km look-ahead horizon). These vectors can be calculated at each time step and used to determine when to take action to meet vehicle speed requirements, such as target vehicle speed before descent, target transmission gear before descent (where applicable), target electric system state before descent (where applicable), downhill speed target, downhill target transmission gear (where applicable), downhill electric system target state (where applicable), and / or hill descent target speed, hill descent target transmission gear (where applicable), and hill descent electric system target state (where applicable).

[0054] On the other hand, during the preparation period before going downhill (e.g., when the vehicle is on a generally flat road section) and when the vehicle has reached its target speed, the PDSC can execute a pseudo cruise control mode to automatically provide fuel to the vehicle, thereby maintaining that target speed on a flat road.

[0055] On the other hand, PDSC can execute correction mechanisms during the gradual descent process before a downhill section. For example, if the vehicle's mass has been underestimated or overestimated, PDSC can observe the error during the pre-descent preparation operation and, as the vehicle approaches the apex of the downhill section, command corrections in the form of reducing or increasing fuel supply, reducing or increasing electric braking, reducing or increasing engine braking, and / or more aggressive or gentler downshifts, and / or utilizing the vehicle's base brakes. In this way, PDSC can rely on the fact that its predictions become more accurate over time as it approaches the apex of the downhill section, thus making the correction actions effective.

[0056] On the other hand, when the powertrain reducer cannot control downhill speed and cannot downshift (e.g., due to complete GPS loss), the PDSC engages the vehicle's base brake to reduce engine speed, thus enabling downshifting. Other situations where the base brake can be used include when uncertainties exist in the PDSC's input signals (such as vehicle mass estimates, gradient data). The PDSC can utilize a margin factor from the engine deceleration torque curve for robustness. If the base brake temperature rises, the margin factor can be higher to reduce the likelihood that the base brake will need to be used. A higher margin may result in downshifting the target transmission gear (where applicable) and vehicle speed during downhill driving. Different braking techniques may produce different braking temperature profiles. Therefore, calibration of the braking parameters can be obtained to allow the PDSC to achieve low braking temperatures associated with base brake operation requests. During transmission shifts, the PDSC can utilize the base brake as a torque-filling device to maintain vehicle speed during downhill driving.

[0057] On the other hand, PDSC can utilize a feedback mechanism to determine whether the vehicle is accelerating or speeding, even if the powertrain reducers are already being used at their maximum capacity, or whether they are not being used at their predicted maximum capacity. For example, if the vehicle mass has been underestimated and the actual road gradient is greater than the predicted gradient, PDSC might determine the desired gear is 12, when the actual desired gear should be 8. In this scenario, PDSC can maximize the utilization of the powertrain reducers and apply the base brakes to slow the vehicle to a speed at which the transmission can downshift, and then perform the downshift. This sequence can be repeated until the vehicle has reached a safe downshift gear (where applicable) and speed. PDSC can use a similar feedback mechanism when GPS data has been lost and the safe gear (where applicable) has been similarly incorrectly determined. In another instance, when the powertrain compares actual power with predicted power without using its predicted deceleration capacity, PDSC can execute an upshift mechanism to reach a higher gear (where applicable). A specific scenario where this mechanism can be applied is when forward-looking data is lost and the vehicle returns to a flat road, the PDSC can identify this and restore the vehicle to its normal state.

[0058] In some scenarios, the driver can further reduce the vehicle speed from the PDSC target speed, such as in a construction zone where the predicted speed limit does not reflect the actual speed limit. The PDSC can support a sequence of driver intervention mechanisms, where the driver depresses the base brake to reduce the vehicle speed. After using the base brake, the driver can depress the accelerator pedal to increase the vehicle speed, during which the PDSC limits the vehicle speed and responsiveness to the accelerator pedal request to predetermined speed limits (such as one of the limits disclosed herein) and / or acceleration limits (such as acceleration ramp limits). If the driver depresses the accelerator pedal in an attempt to exceed the PDSC target speed and / or target acceleration, the PDSC can limit the vehicle speed and / or acceleration within these limits.

[0059] In some scenarios, the driver can intervene in the manual gear selection request during PDSC operation, for example, by manually downshifting the transmission gear (where applicable) below the gear initially selected by PDSC. In such scenarios, PDSC can select the final transmission gear (where applicable) as the minimum between the PDSC gear selection request and the driver's gear selection request. Because the PDSC command speed responds to the final transmission gear (where applicable) request, the PDSC command speed can be further reduced from the initial PDSC command speed if the final gear selection request is the gear requested by the driver.

[0060] In some scenarios, the driver can intervene in PDSC operation using a basic brake request. For example, the driver might depress the basic brake pedal further to achieve a greater desired vehicle deceleration than the PDSC would normally provide. In such a scenario, the driver's basic brake can override the PDSC request. In another scenario, the final basic brake request can be a combined request for braking from both the PDSC and the driver.

[0061] On the other hand, PDSC can perform hill descent control (HRO) by utilizing the gradient at the end of the downhill section, thereby meeting the indicated speed limit requirements by reducing electric braking, increasing fuel economy and / or improving driving performance.

[0062] On the other hand, PDSC can perform hill descent control (HRO) by utilizing the slope at the end of the downhill section, thereby meeting indicated speed limits, increasing fuel economy, and / or improving driving performance by performing reverse towing, coasting in neutral, or coasting with the engine off.

[0063] PDSC can perform any type of HRO operation, depending on the context. Figures 3A to 3C The examples shown, but not limited to, are as follows: Figures 3A to 3C The topology indicates speed limits and slope. Figure 3AIn the first instance of HRO operation, a marked speed limit is added before the end of the downhill section, and the PDSC increases the downhill speed target to allow vehicle speeds to gradually increase to the increased marked speed limit while on the downhill section. The level of change in vehicle speed gradient before the increased marked speed limit can be determined by a predetermined calibration of the amount of vehicle speed above the marked speed limit on the downhill section, and / or by meeting the requirement that the difference between the vehicle speed and the marked speed on the downhill section is less than the predetermined calibration. The amount of vehicle speed allowed above the marked speed limit on the downhill section can be determined based on the marked speed limit on the downhill section and the increased marked speed limit.

[0064] exist Figure 3B In the second instance of HRO operation, at or after the end of a downhill section, the indicated speed limit is increased, and the PDSC increases the downhill speed target to allow vehicle speed to gradually increase to the increased indicated speed limit as the vehicle descends the section. At and after the end of the downhill section, the PDSC limits vehicle speed to prevent it from exceeding the allowed vehicle speed gradient level before the increased indicated speed limit, regardless of driver acceleration. The level of change in vehicle speed gradient before the increased indicated speed limit can be determined by a predetermined calibration of the amount of vehicle speed above the indicated speed limit during the downhill descent, and / or by meeting the requirement that the difference between the vehicle speed and the indicated speed during the downhill descent is less than the predetermined calibration. The amount of vehicle speed allowed above the indicated speed limit during the downhill descent can be determined based on the indicated speed limit during the downhill descent and the increased indicated speed limit.

[0065] exist Figure 3C In the third example of HRO operation, the indicated speed limit is not changed before, during, and after the descent, and the PDSC increases the vehicle speed from the target descent speed back to the indicated speed. In some operational scenarios, HRO operation may be disabled due to low-confidence predictions of the obtained vehicle speed. In some operational scenarios, if the vehicle speed is higher than the target during HRO, HRO operation can switch to powertrain deceleration operation, where the transmission is held or downshifted (where applicable) for a period of time near the end of the descent segment.

[0066] For applications with more than one reduction gear, the reduction power capability used by PDSC can be the combined power capability of all reduction gears. This combined power capability is used to determine the target speed and target gear, as well as the timing of the gradual downshift / downshift before descending a slope. If the reduction gear is a powertrain reducer, its corresponding power curve takes into account the effects of coolant and oil temperature. These temperatures can also be derived from predictive models based on prospective data. Reduction gears can include, but are not limited to, any device that provides reduction power, electric motors, compression release brakes, exhaust valves, VGTs, exhaust throttles, intake throttles, all types of powertrain reducers (hydraulic, electromagnetic, etc.), engine / vehicle accessories (compressors, fans) or any parasitic loads, aerodynamic enhancers / reduction gears (such as air deflectors and automatic chassis lowering systems), and multi-axles (to increase rolling friction and axle losses).

[0067] In such applications, the PDSC can perform reactive and proactive actions. In reactive actions, when the coolant temperature of the powertrain reducer is high, its braking capacity decreases. This power reduction performance of the powertrain reducer is taken into account and may lead to a reduction in the calculated target speed and gear. This control action occurs continuously, including before and during a downhill descent. In proactive actions, if the controller predicts that the powertrain reducer may lead to a power reduction state, the power curve used by the controller can be further reduced from its instantaneous power capacity to prevent the powertrain reducer from reducing power or to proactively reach the correct target gear and speed to address the impending power reduction issue from the powertrain reducer.

[0068] If reduction gears with different braking torque / power transmission resolutions exist, the high-resolution reduction gear is used to assist the low-resolution reduction gear, enabling the powertrain to transmit high-resolution braking torque / power, thereby achieving good vehicle speed control during downhill driving. For reduction gears controlled by their own control modules, speed / torque / power requests (such as J1939 TSC1 messages) can be used by the electronic control unit (ECU) operating the PDSC.

[0069] During torque interruption, the transmission shifts gears when the prime mover's braking power is lost. Any other reduction devices (such as powertrain reducers or vehicle-based brakes) can be used as torque-filling devices to compensate for the loss or reduction in prime mover deceleration power during transmission gear shifts (where applicable). Predictive information can be used to ensure that the power of these reduction devices is reserved for use during gear shifts.

[0070] In some operational scenarios, PDSCs may face the loss of prospective data. The loss of prospective data can be sudden (e.g., due to GPS or navigation system malfunction) or gradual (e.g., due to vehicle movement, the route between two points may not have been mapped). In the case of sudden prospective data loss, the PDSC can be configured to take predictive actions solely based on current prospective data (exactly before or prior to data loss). Past prospective data and decisions (before data loss) can be excluded. This is a conservative approach, assuming that past prospective data is unreliable and cannot be depended upon. In some embodiments, the PDSC can utilize past prospective data (before data loss) to make control decisions. In the case of gradual prospective data loss, the PDSC can utilize past prospective data (before data loss) to make control decisions.

[0071] In some operating scenarios, the PDSC may encounter vehicle speed sensor malfunctions (e.g., a faulty transmission output shaft speed sensor or loss of data from it). In such scenarios, the PDSC can use engine speed and the number of transmission gears (where applicable) to determine the corresponding vehicle speed for its operation. During gear shifts, this vehicle speed can be considered constant.

[0072] In some operational scenarios, if the PDSC faces the loss of forward-looking data, other sensors (such as cameras and LiDAR) can be used to provide forward-looking slope and indicate speed limits. In one embodiment, the accuracy of forward-looking data can be improved by fusion of cloud-based forward-looking devices e-Horizon, cameras, LiDAR, and road slope sensors.

[0073] On the other hand, PDSC can perform adaptive actions to adjust its parameters, such as the margin factor of the engine braking torque curve, based on the actions performed by PDSC in response to the feedback mechanism. The engine braking torque curve can take into account the effects of altitude, at which engine braking capacity is limited by nominal conditions. A power reduction model using the engine braking torque curve with ambient air pressure can be used by PDSC in its prediction algorithm. An ESS power reduction model can be used by PDSC in its prediction algorithm. An electric motor power reduction model can be used by PDSC in its prediction algorithm. A basic brake power reduction model can be used by PDSC in its prediction algorithm. Other power reduction models for powertrain reducers can be used by PDSC in their prediction algorithms.

[0074] On the other hand, PDSC can utilize vehicle-to-everything (V2X) communication to consider the impact of traffic (including surrounding vehicles and traffic lights in addition to the indicated speed limit) to determine the effective indicated speed limit and use it as input for the feature. In one embodiment, a recommended speed can be considered as part of determining the effective indicated speed limit. Other information such as weather (rain, snow, strong winds) and road conditions can be used to determine vehicle dynamics parameters and the effective indicated speed limit, taking into account the effects of these factors. In one embodiment, icy or wet road conditions can be used to optimize the vehicle deceleration process to avoid events such as folding knives, for example, if a vehicle behind loses forward vision, the vehicle in front can provide / supplement electronic horizon information due to vehicle-to-vehicle (V2V) communication. While all the main calculations for the feature can occur within the ECU, some additional advanced and cumbersome calculations can be performed in the cloud and the information transmitted to the ECU.

[0075] On the other hand, the PDSC determines its operating mode (e.g., disabled mode, inactive mode, active mode, degraded mode, and fault mode), and the PDSC communicates its mode, speed target, and transmission gear (where applicable) request to be displayed on the vehicle's dashboard. An example of a degraded mode is when forward-looking data is unavailable and the PDSC uses only its feedback mechanism to protect the vehicle. The feedback mechanism can utilize different types of sensors or virtual sensors (such as engine speed, vehicle speed, engine torque, temperature of electrified components, temperature of the base brakes, and temperature of other powertrain reducers) to take control actions. In another instance, the configuration matching between the ECU with the PDSC and the electronic horizon can be a digital verification process to ensure the presence of forward-looking parameters. If not, the PDSC can be set to a fault or inactive mode to warn the driver. On the other hand, the PDSC can automatically activate four-way hazard lights / hazard indicators.

[0076] Machine Mass Estimator (MME) and Vehicle Parameter Determination (VPD) features can be used in the prediction algorithm within the PDSC. As used in this paper, VPD is a feature that determines all of a vehicle's dynamic losses, including rolling friction losses, aerodynamic losses, and powertrain losses. Various sensors can be used to improve these estimates, such as torque sensors, wind sensors, cameras (for detecting road surfaces to enable rolling resistance modeling), and pressure sensors in airbags to estimate the vehicle's mass sitting on a bridge. Measurements from these sensors can be fused with currently used production sensors for these features to improve the prediction algorithm in the ECU.

[0077] refer to Figure 4The illustration shows a flowchart of example method 300, which is used to dynamically adjust the speed of vehicle 100 to approach a target speed, change the gear of transmission 106, and adjust the state of power system 117 (e.g., electric motor 151, power electronics 153, and / or ESS 155) before or at the time of reaching a downhill section of the route (such as downhill section 204) while the vehicle is traveling along downhill route segment 204, in addition to dynamically adjusting the vehicle speed, transmission gear (where applicable), and power system state (where applicable).

[0078] Method 300 begins at operation 302, in which, in response to the target speed of vehicle 100, the target gear of transmission 106, and the target state of powertrain 117 (e.g., electric motor 151, power electronics 153, and / or ESS 155), control procedures are initiated to control vehicle speed, shift transmission gears (where applicable), and control the state of powertrain 117 or its components (where applicable) up to downhill section 204. As described above, the target speed can be determined based on the forward road gradient and speed limits along downhill section 204.

[0079] Operation 302 can be initiated by interpreting an activation event, loop completion, restart method 300, by initiating a vehicle operation (such as a towing condition), or by being initiated by a vehicle operator or technician. As used herein, a towing condition is an operating condition in which the prime mover system 103 does not require fuel to propel the vehicle 100, such as when the throttle is closed, the accelerator pedal 145 is raised, the accelerator pedal 145 is in a dead zone region where no fuel is required, and / or when the accelerator pedal 145 is not depressed.

[0080] Method 300 continues from operation 302 at operation 304. Operation 304 includes monitoring look-ahead conditions along route 202, such as approach road gradient, gradient length, and vehicle speed limits, to name just a few. It is conceivable that in some embodiments, look-ahead conditions may include the road gradient and speed limits for the entire route 202. In other embodiments, look-ahead conditions are for a portion of the route preceding downhill section 204, the downhill section, and a portion of the route preceding the downhill section, all of which are controlled using method 300 to control vehicle speed.

[0081] Method 300 proceeds from operation 304 to operation 306, where operation 306 determines forward road gradient and speed limit parameters. Method 300 proceeds from operation 306 to operation 308, where operation 308 includes determining forward vehicle operating parameters. Such forward vehicle operating parameters may include predicted future vehicle speed (e.g., terminal vehicle speed), predicted future transmission gear (e.g., terminal transmission gear), and predicted future power system state (e.g., terminal power system state), such as the energy storage level or capacity and / or temperature of one or more components of the power system (e.g., electric machinery, power electronics, or energy storage systems, and other components).

[0082] Method 300 proceeds from operation 308 to operation 310, whereby operation 310 includes determining forward vehicle target parameters. Such forward vehicle target parameters may include forward target speed, forward target transmission gear (where applicable), and forward target power system state, such as target energy storage level or capacity and / or target temperature of one or more components of the power system (e.g., electric machinery, power electronics, or energy storage systems, and other components). As described above, such forward vehicle target parameters may be determined in response to vehicle configuration, vehicle mass, road gradient, and other conditions. Such forward vehicle target parameters may be updated continuously during the operation of vehicle 100 or periodically in response to operating parameters being input into the ECS along the route.

[0083] Method 300 proceeds from operation 310 to condition 312, which assesses whether any pre-descent maneuver is required as the vehicle approaches the downhill section of route 202. If condition 312 is assessed as "no," method 300 continues to operation 304 to continue monitoring look-ahead conditions along route 202. If condition 312 is assessed as "yes," indicating that action is required, method 300 continues from condition 312 to operation 314.

[0084] Operation 314 determines the vehicle operation parameters before the downhill section and uses these parameters to control the vehicle's operation. The vehicle operation parameters before the downhill section may include the target vehicle speed before the downhill section, the target transmission gear (where applicable), and the target electrical system status (where applicable). The vehicle operation parameters before the downhill section can be selected before or upon arrival at the downhill section. These parameters can be selected to help maintain the desired downhill vehicle speed.

[0085] From operation 314, method 300 proceeds to operation 316, where operation 316 controls the speed of vehicle 100 while traveling along downhill section 204. During operation 316, one or more components of the vehicle's powertrain can be controlled during the downhill section to reduce or maintain the vehicle speed to meet the downhill vehicle speed target. In some cases, the powertrain reducer can be controlled to reduce or maintain the vehicle / engine speed during the downhill section without applying the base brake to meet the downhill vehicle speed target. In some cases, the transmission can be downshifted to a lower gear during the downhill section to reduce or maintain the vehicle / engine speed to meet the downhill speed target. In some cases, the base brake can be operated during the downhill section to reduce or maintain the vehicle speed to meet the downhill speed target, and the engine speed can be controlled to meet the engine speed limit.

[0086] From operation 316, method 300 proceeds to operation 318 to continue monitoring look-ahead conditions along route 202. From operation 318, method 300 proceeds to operation 320 to determine target coasting parameters. Target coasting parameters may include target coasting speed, target coasting gearbox gear (where applicable), and target coasting electrical system status (where applicable). The target coasting speed may be determined in response to a first indicated speed limit for that section of the downhill route segment and a second indicated speed limit for the route segment preceding or ahead of that section of the downhill route segment.

[0087] From operation 320, method 300 proceeds to condition 322 to determine whether the vehicle is approaching the end of the downhill section of route 202 and whether a steep slope gliding maneuver is required. If condition 322 is "No", method 300 continues to operation 318 to continue monitoring look-ahead conditions along route 202. If condition 322 is "Yes", indicating that the end of the downhill section of route 202 is approaching and a steep slope gliding maneuver can be performed, method 300 continues to operation 324.

[0088] Method 300 executes operation 324, where, when the vehicle reaches a portion of the downhill section of route 202, it controls the vehicle to accelerate toward the target gliding speed (if necessary, since the current vehicle speed is lower than the target gliding speed). From operation 324, method 300 proceeds to condition 326 to determine if the end of the downhill section has been reached. If condition 326 is "No," method 300 proceeds to operation 324 to continue accelerating along route 202 to the target gliding speed. If condition 326 is "Yes," indicating that the end of the downhill section of route 202 has been reached, method 300 proceeds to operation 328. The process executes operation 328 to switch the PDSC to an inactive mode. Method 300 then completes and ends at operation 330, where method 300 can restart as discussed above regarding operation 302.

[0089] This disclosure provides an advanced look-ahead control feature that electronically controls the vehicle when traversing a steep incline by selecting optimal powertrain decisions specifically for the engine, transmission, electrical system, base brakes, and other reducers, thereby ensuring a safe and controlled descent.

[0090] Various aspects of this disclosure are envisioned. According to one aspect, a vehicle system is provided, the vehicle system comprising: a powertrain including a prime mover and a transmission coupled to the prime mover; one or more powertrain reducers; one or more ground engagement wheels coupled to the transmission and capable of being driven by the prime mover through the transmission; an electrical system; base brakes actuated to decelerate the one or more ground engagement wheels; and an electronic control system operatively communicating with the prime mover, transmission, electrical system, and base brakes.

[0091] See Figure 5 The illustration depicts certain aspects of an example control 400, which may be implemented and provided in the VSM control unit 150 and / or one or more other control units or other components of the ECS associated with the vehicle 100 and powertrain 102. The controller 400 is configured and operable to perform the PDSC, HRO, and other powertrain and vehicle control operations of this disclosure.

[0092] The controller 400 includes a route parameter manager 410, which is configured and operable to receive GPS information 407 and vehicle-to-everything (V2X) information 409, and in response to one or both of these inputs to determine and provide forward road gradient information 413 and forward speed limit information 415 as outputs.

[0093] Control 400 includes a model-based predictor 426 configured and operable to receive input 402. In the example shown, the model-based predictor 426 receives forward road gradient information 413 and forward speed limit information 415. The model-based predictor 426 also receives current vehicle operating parameters 403, a base brake temperature estimate 404, an electrical system limit 405, and a base brake limit 406. In response to the received input, the model-based predictor 426 determines predicted vehicle operating parameters 430, which may include multiple parameters such as vehicle speed, engine speed, state of charge (SOC), state of health (SOH), gear position, and the status and / or temperature of electrified components (ESS, electric motors, power electronics, etc.).

[0094] Current vehicle operating parameters 403 may include, for example, vehicle speed, road gradient, vehicle mass, the state of the vehicle's aerodynamic characteristics, engine speed, engine torque and / or engine power, current transmission gear position, information regarding the state of one or more powertrain reducers, and / or other information regarding the vehicle's current operating parameters. Information regarding the state of one or more powertrain reducers may include, for example, engine braking status, hydraulic drivetrain reducer status, electromagnetic drivetrain reducer status, powertrain / vehicle accessory status, temperature of electrical system components (e.g., electric motor temperature, power electronic device temperature, and / or ESS temperature), ESS state of charge parameters, ESS health status parameters, electric motor operating mode parameters, exhaust valve position parameters, VGT position parameters, exhaust throttle position parameters, intake throttle position parameters, and other information regarding the state of one or more powertrain reducers as would be conceived by a person skilled in the art based on the benefits and teachings of this disclosure.

[0095] The base brake temperature estimation 404 may include estimating the current temperature of one or more service brake components once or multiple times. The electrical system limitation 405 may include one or more limitations on temperature, speed, power, current, voltage, or other limitations associated with one or more components of the electrical system. The base brake limitation 406 may include one or more limitations on the base brake temperature.

[0096] The predicted vehicle operating parameters 430 can be provided as input to the control state determination logic 429 and the control action determination logic 424. The control state determination logic 429 determines whether an action from the control 400 is required to provide the desired and / or safe descent. If an action is required, the control action determination logic 424 determines and outputs one or more requests or commands 480 for preparatory or responsive actions of the vehicle approaching or descending the slope.

[0097] Requests or commands 480 for preparatory or responsive operation may include engine braking request 482, machine torque / speed / power request 484 (e.g., regenerative or other electric braking), transmission gear selection request 486, base brake request 488, and other torque / speed / power requests 492 (e.g., torque / speed / power requests for one or more other reducers and engine or other drivetrain components). Requests or commands 480 for preparatory or responsive operation may also include electrical system preconditioning request 494 and other preconditioning requests 494, which may precondition one or more components of the electrical system to provide state of charge (SOC), temperature, vehicle speed, and transmission gear selection to achieve desired power absorption capacity.

[0098] Requests or commands 480 for preparatory or responsive operations may be provided to one or more control units of the electronic control system (such as those described herein), processed by one or more control units of the electronic control system, and / or executed by one or more control units of the electronic control system. Driver intervention input 411 is also provided to the model-based predictor 426 and control action determination logic 424, and may modify or interrupt the generation of requests or commands 480 for preparatory or responsive operations.

[0099] The control action determination logic 424 can utilize arbitration to determine which components have a higher priority for performing vehicle braking. These components include the battery, engine, electric motor, accessories, other reducers, and service brakes. The battery or other ESSs can be assigned the highest priority. The base brake may be assigned the lowest priority due to its impact on the service brake's lifespan. The power / torque curves of these components, and other optimized metrics such as component lifespan, thermal conditions, and emissions are taken into account when making the decision. In one embodiment, the priority order is: battery, accessories, other reducers, engine reducer, and last-used service brake.

[0100] The control action determination logic 424 can be configured and operable to command, increase, and maximize the operation of the thermal management system to cool the battery or other ESS, electric machinery, power electronic devices and / or other electrified components more, resulting in a higher ability to absorb regenerative power and increased energy consumption due to thermal management.

[0101] The control action determination logic 424 can be configured and operable to determine the required regenerative power using a physics-based approach. DDBC will select the regenerative power based on downhill conditions (for protection against speeding) and environmental conditions (for protection against wheel slippage, drivability, etc.), particularly for the series powertrain in a 6×4 configuration. This applies to all types of powertrains considered. The 6×4 configuration powertrain has additional control levers due to its power distribution capability between the two axles. The powertrain in a 6×4 configuration can distribute power between the axles before and after the downhill descent to optimize fuel and energy economy and maintain vehicle speed at or below the downhill speed target while protecting the vehicle from wheel slippage or drivability issues. In one embodiment, one axle operates at prime mover power between continuous and peak power, and the other axle operates at prime mover power between peak and continuous power to obtain total power, but the prime mover operates at peak power for no longer than a duration limit. In another embodiment, one axle is unpowered, and the other axle operates at prime mover power between peak and continuous power. Alternatively, the two bridges can operate at different power distribution levels and at different power levels, ranging from the minimum power to the peak power of the prime mover.

[0102] The target vehicle speed for downhill driving can be calculated based on the total reduction gear capacity of the system, which includes various powertrain components such as a traction motor, engine reducer, and accessories. For example, in a parallel hybrid system, when both the engine reducer and the electric system are available to participate in decelerating the vehicle, the total braking power is at its maximum and a specific target speed will be allowed. When the electric system is unavailable, a different target speed can be selected. For a series hybrid system, a specific target speed can be selected when the battery has sufficient capacity to absorb regenerative energy. When the battery's state of charge (SOC) cannot absorb regenerative energy (SOC at maximum, too cold, etc.), the engine reducer or braking resistor via the generator set can be used, but the same level of vehicle braking force may not be allowed, thus a different target speed can be selected.

[0103] See Figure 6The diagram illustrates a set of graphs 600 depicting example operation of a vehicle 100 traveling along a route approaching and subsequently descending to a downhill section. During the section between points 602 and 604, the state of charge (SOC) of the energy storage system (ESS) is reduced to pre-regulate the battery for regenerative braking during the downhill section of the route. Additionally, at point 604, the vehicle speed is reduced to pre-regulate the vehicle so that it begins the downhill section at a slower speed. Furthermore, one or more electrification components are pre-cooled to lower their temperature, thereby pre-regulating the electrification components to absorb more electricity on the downhill section between points 604 and 608. During the downhill section between points 604 and 606, the vehicle speed is kept constant by electric braking performed by the electrification components and other powertrain decelerators, such as engine brakes, and the temperature of the electrification components fluctuates. Between points 606 and 608, the vehicle speed is allowed to increase during coasting operations.

[0104] See Figure 7 The diagram illustrates a set of graphs 700 depicting example operation of vehicle 100 traveling along a route between multiple points 702, 704, 706, and 708, including a downhill section. Between points 704 and 706, the state of charge (SOC) of the energy storage system (ESS) increases due to regenerative braking performed on the downhill section, while the vehicle speed remains constant. Regenerative braking can be alternated between the front series electric drive axle and the rear series electric drive axle by switching between continuous power curves and peak power curves to maximize and maintain total braking power / performance while protecting components from power reduction and providing the necessary peak regenerative power when there are short / intermediate requests, such as short-duration downhill sections or when the vehicle speed needs to be reduced for further downshifting.

[0105] This feature can be used as part of overall look-ahead control to predict the duration for which a component can remain at peak power. For example, based on look-ahead, this feature can determine to perform pre-cooling / maximize cooling of components (e.g., battery, motor) before descent to enable them to reach peak power during descent. Pre-cooling components before descent also helps release SOC, which allows for more regenerative energy during vehicle descent. Switching power between the continuous power curve and the peak power curve helps maximize and maintain total braking power / performance while protecting components from power reduction and providing the necessary peak regenerative power when there are short / intermediate requests such as short-duration descents or when the vehicle speed needs to be reduced for further downshifting.

[0106] In an electrified powertrain (e.g., a series hybrid or series-parallel hybrid) with an engine mechanically connected to an electric motor via power electronics, one or more of the following—DC bus voltage, traction motor operation, and engine braking—can be used to dissipate electric braking energy by operating in a towing mode or engine braking mode, in addition to other regenerative components (such as batteries, accessories, supercapacitors, and other reducers). In some such embodiments, if the battery and electrification components can absorb all the regenerative energy during downhill driving, the vehicle can be controlled to perform engine-off coasting and neutral coasting to reduce frictional losses during downhill driving.

[0107] In electrified powertrains such as parallel hybrid and series-parallel hybrid systems, if the battery and electrification components can absorb all the electric braking energy on a given downhill route, the vehicle can be controlled to perform engine-off coasting and neutral coasting to reduce friction losses when going downhill.

[0108] In an electrified powertrain (such as a parallel or series-parallel powertrain) with an engine mechanically connected to a traction device, electric motors, vehicles or powertrain accessories, supercapacitors, other reduction gears, and engine reduction gears can be used for braking. Electric motors connected to a battery can be used for regenerative braking, and the engine can operate in reverse or engine braking modes as needed, for example, when the battery's state of charge (SOC) is high and it cannot absorb electric braking energy.

[0109] For some parallel hybrid architectures (e.g., Powertrain 1104 or Powertrain 1105), electric motors can be used as torque-filling devices to provide traction on downhill sections during gear shifts.

[0110] For parallel hybrid architecture, during downhill operation, when engine braking is required in addition to regenerative braking, the electric motor can be used to enhance vehicle speed control performance due to the high resolution of torque transmission from the electric motor.

[0111] For an architecture with an electric drive axle having multiple gears, the same strategy described for a transmission can be applied to the electric drive axle gears.

[0112] As shown in this detailed description, this disclosure contemplates several embodiments, including the following example embodiments.

[0113] Example embodiment 1 is a vehicle system comprising: a powertrain including a prime mover system, the prime mover system including an electric system, the electric system including an energy storage system (ESS), power electronic devices operatively connected to the ESS, and electric motors operatively connected to the power electronic devices; one or more ground engagement wheels operatively connected to the prime mover system; and an electronic control system operatively communicating with the prime mover system, the electronic control system being configured to: determine a target vehicle speed before reaching a downhill section, a target state of the electric system before reaching a downhill section, and a target downhill vehicle speed before reaching a downhill section; control the vehicle system to achieve the target vehicle speed before reaching the downhill section or upon reaching the downhill section; and operate the electric system to perform electric braking during the downhill section to control the vehicle speed according to the target downhill vehicle speed.

[0114] Example embodiment 2 includes the features of example embodiment 1, wherein the ESS includes a battery system, the target state of the power system before the downhill includes a target battery state of charge, and the electronic control system is configured to control the ESS to provide the target battery state of charge before the downhill section.

[0115] Example embodiment 3 includes the features of example embodiment 2, wherein the target battery state of charge is achieved by discharging the battery before the downhill section to increase the available battery energy storage capacity.

[0116] Example embodiment 4 includes the features of example embodiment 1, wherein the power system includes a thermal management system, the target state of the power system before the downhill section includes at least one target power system temperature, and the electronic control system is configured to control the thermal management system to provide the at least one target power system temperature before the downhill section.

[0117] Example embodiment 5 includes the features of example embodiment 4, wherein the target power system temperature is achieved by cooling one or more of the ESS, the power electronic devices, and the electric motors before the downhill section to increase the energy storage capacity of the power system.

[0118] Example embodiment 6 includes the features of example embodiment 1, wherein the prime mover system includes an engine operatively coupled to the one or more ground engagement wheels via a clutch, and the electronic control system is configured to operate the electrical system to perform electric braking concurrently with a coasting operation during the downhill section, in which the clutch is disengaged to disengage the engine from the ground engagement wheels.

[0119] Example embodiment 7 includes the features of example embodiment 1, wherein the electronic control system is configured to operate the electric system to perform electric braking during the downhill section to control vehicle speed according to the downhill vehicle speed target, including switching the operation of the electric machine between peak power operation and continuous power operation.

[0120] Example embodiment 8 includes the features of example embodiment 1, wherein the prime mover system includes one of a series hybrid system and a series-parallel hybrid system, the prime mover system includes an engine operatively connected to the electric motor, and the electronic control system is configured not to charge the ESS and to operate the engine to apply a load to the electric motor to control the vehicle speed according to the downhill vehicle speed target.

[0121] Example embodiment 9 includes the features of example embodiment 1, wherein the prime mover system includes one of a parallel hybrid system, a road-connected parallel hybrid system, and a series-parallel hybrid system, and the electronic control system is configured not to charge the ESS from the power electronics and to operate the engine to apply loads to the one or more ground engagement wheels to control the vehicle speed according to the downhill vehicle speed target.

[0122] Example embodiment 10 includes the features of example embodiment 1, wherein the electronic control system is configured to: determine a target coasting speed of the vehicle system on a portion of the downhill route; and when the vehicle system reaches the portion of the downhill route, control the vehicle system to accelerate toward the target coasting speed by one of the following operations: performing one of engine towing, neutral coasting, and engine-off coasting, and operating the electric motor to reduce the amount of electric braking.

[0123] Example embodiment 11 includes the features of example embodiment 1, wherein the prime mover system includes an engine, and the electronic control system is configured to operate the electrical system to perform electric braking concurrently with one of engine dragging operation and engine braking operation during the downhill section.

[0124] Example embodiment 12 includes the features of example embodiment 1, wherein the electronic control system is configured to perform one or more of the following operations: (a) operating the electric motor to provide torque during transmission shifts, thereby mitigating power interruption during shift events; (b) downshifting one of the transmission gears and the electric drive axle gears before reaching a downhill section; and (c) upshifting one of the transmission gears and the electric drive axle gears during the downhill section.

[0125] Example embodiment 13 includes the features of example embodiment 1, wherein the electronic control system is configured to drive the prime mover system in response to a driver's acceleration request to accelerate the vehicle system during downhill operation.

[0126] Example embodiment 14 is a process for controlling the operation of a vehicle system, the vehicle system comprising: a powertrain including a prime mover system, the prime mover system including an electric system including an energy storage system (ESS), power electronic devices operatively connected to the ESS, and electric motors operatively connected to the power electronic devices; one or more ground engagement wheels operatively connected to the prime mover system; and an electronic control system operatively communicating with the prime mover system, the method comprising operating the electronic control system to perform the following actions: determining a target vehicle speed before reaching a downhill section, a target state of the electric system before reaching the downhill section, and a target downhill vehicle speed before reaching the downhill section; controlling the vehicle system to achieve the target vehicle speed before reaching the downhill section or upon reaching the downhill section; and operating the electric system to perform electric braking during the downhill section to control the vehicle speed according to the target downhill vehicle speed.

[0127] Example embodiment 15 includes the features of example embodiment 14, wherein the ESS includes a battery, and the target state of the power system before the downhill section includes a target battery state of charge, and the method includes operating the electronic control system to control the ESS to provide the target battery state of charge before the downhill section.

[0128] Example embodiment 16 includes the features of example embodiment 15, including discharging the battery before the downhill section to achieve the target battery state of charge and increase the available battery system energy storage capacity.

[0129] Example embodiment 17 includes the features of example embodiment 14, wherein the power system includes a thermal management system, and the target state of the power system before the downhill section includes a target power system temperature, and the method includes operating the electronic control system to control the thermal management system to provide the target power system temperature before the downhill section.

[0130] Example embodiment 18 includes the features of example embodiment 17, wherein one or more of the ESS, the power electronic devices, and the electric motor are cooled before the downhill section to achieve the target power system temperature, thereby increasing the energy storage capacity of the power system.

[0131] Example embodiment 19 includes the features of example embodiment 14, wherein the prime mover system includes an engine operatively coupled to the one or more ground engagement wheels via a clutch, and the method includes: operating the electronic control system configured to operate the electrical system to perform electric braking concurrently with a coasting operation during the downhill section, in which the clutch is disengaged to disengage the engine from the ground engagement wheels.

[0132] Example embodiment 20 includes the features of example embodiment 14, including: during electric braking during the downhill section, switching the operation of the electric motor back and forth between peak power operation and continuous power operation to control the vehicle speed according to the downhill vehicle speed target.

[0133] Example embodiment 21 includes features of example embodiment 14, including: operating the electronic control system to not charge the ESS from the power electronics, and operating the engine to apply a load to the electric motor to control the vehicle speed according to the downhill vehicle speed target.

[0134] Example embodiment 22 includes features of example embodiment 14, including: operating the electronic control system to not charge the ESS from the power electronics, and operating the engine to apply loads to one or more ground engagement wheels to control vehicle speed according to the downhill vehicle speed target.

[0135] Example embodiment 23 includes features of example embodiment 14, including operating the electronic control system to: determine a target coasting speed of the vehicle system on a portion of the downhill route; and when the vehicle system reaches the portion of the downhill route, control the vehicle system to accelerate toward the target coasting speed by one of the following operations: performing one of engine towing, neutral coasting, and engine-off coasting, and operating the electric motor to reduce the amount of electric braking.

[0136] Example embodiment 24 includes the features of example embodiment 14, wherein the prime mover system includes an engine, and the method includes: operating the electronic control system to operate the electrical system, thereby performing electric braking concurrently with one of engine towing operation and engine braking operation during the downhill section.

[0137] Example embodiment 25 includes features of example embodiment 14, including one or more of the following: (a) operating the electric motor to provide torque during transmission shifting, thereby mitigating power interruption during shifting events; (b) downshifting either the transmission gear or the electric drive axle gear before reaching a downhill section; and (c) upshifting either the transmission gear or the electric drive axle gear during the downhill section.

[0138] Example embodiment 26 includes the features of example embodiment 14, wherein the prime mover system includes a series hybrid system including an engine operatively coupled to the electric motor, and the method includes operating the electronic control system in response to a driver acceleration request to drive the prime mover system to accelerate the vehicle system during downhill operation.

[0139] While illustrative embodiments of the present disclosure have been shown and described in detail in the accompanying drawings and the foregoing description, their nature should be considered illustrative rather than restrictive. It should be understood that only certain exemplary embodiments have been shown and described, and protection is intended for all variations and modifications falling within the spirit of the claimed invention. It should be understood that while the use of terms such as “preferred,” “ideally,” “preferred,” or “more preferred” in the foregoing description indicates that a feature so described may be more desirable, it may not be necessary, and embodiments lacking these features may be considered within the scope of the invention, as defined by the appended claims. When reading the claims, it is intended that the use of terms such as “a,” “an,” “at least one,” or “at least a portion” does not limit the claims to a single item unless expressly stated otherwise in the claims. When using the language “at least a portion” and / or “a portion,” an item may include a portion and / or the entire item, unless expressly stated otherwise.

Claims

1. A vehicle system comprising: The power system includes a prime mover system, the prime mover system includes an electric system, the electric system includes an energy storage system (ESS), power electronic devices operatively connected to the ESS, and electric motors operatively connected to the power electronic devices. One or more ground engagement wheels, the one or more ground engagement wheels being operatively connected to the prime mover system; as well as An electronic control system capable of operatively communicating with the prime mover system, the electronic control system being configured to: Before reaching the downhill section, determine the target vehicle speed, the target state of the power system, and the target vehicle speed for the downhill section. The vehicle system is controlled to achieve the target vehicle speed and target electrical system state before or upon reaching the downhill section. The electrical system is operated to perform electric braking during the downhill section to control vehicle speed according to the downhill vehicle speed target.

2. The vehicle system of claim 1, wherein the ESS includes a battery system, the target state of the electrical system before the downhill section includes a target battery state of charge, and the electronic control system is configured to control the ESS to provide the target battery state of charge before the downhill section.

3. The vehicle system of claim 2, wherein the target battery state of charge is achieved by discharging the battery system before the downhill section to increase the available battery energy storage capacity.

4. The vehicle system of claim 1, wherein the electrical system includes a thermal management system, the target state of the electrical system before the downhill section includes at least one target electrical system temperature, and the electronic control system is configured to control the thermal management system to provide the at least one target electrical system temperature before the downhill section.

5. The vehicle system of claim 4, wherein the target electrical system temperature is achieved by cooling one or more of the ESS, the power electronics and the electric motor before the downhill section to increase the energy storage capacity of the electrical system.

6. The vehicle system of claim 1, wherein the prime mover system includes an engine operatively coupled to the one or more ground engagement wheels via a clutch, and the electronic control system is configured to operate the electrical system to perform electric braking concurrently with a coasting operation during the downhill section, wherein the clutch is disengaged to disengage the engine from the ground engagement wheels.

7. The vehicle system of claim 1, wherein the electronic control system is configured to operate the electrical system to perform electric braking during the downhill section to control the vehicle speed according to the downhill vehicle speed target, including switching the operation of the electric motor between peak power operation and continuous power operation.

8. The vehicle system of claim 1, wherein the prime mover system comprises one of a series hybrid system and a series-parallel hybrid system, the prime mover system comprising an engine operatively connected to the electric motor, and the electronic control system is configured not to charge the ESS and to operate the engine to apply a load to the electric motor to control the vehicle speed according to the downhill vehicle speed target.

9. The vehicle system of claim 1, wherein the prime mover system comprises one of a parallel hybrid system, a road-connected parallel hybrid system, and a series-parallel hybrid system, the prime mover system comprising an engine, and the electronic control system being configured not to charge the ESS from the power electronics and to operate the engine to apply loads on the one or more ground engagement wheels to control the vehicle speed according to the downhill vehicle speed target.

10. The vehicle system of claim 1, wherein the electronic control system is configured to: Determine the target gliding speed of the vehicle system on a portion of the downhill section; and When the vehicle system reaches the portion of the downhill section, it accelerates toward the gliding target by one of the following operations: Perform one of the following operations: engine reversing, coasting in neutral, or coasting with the engine off. Operate the electric motor to reduce the amount of electric braking.

11. The vehicle system of claim 1, wherein the prime mover system comprises an engine, and the electronic control system is configured to operate the electrical system to perform electric braking concurrently with one of engine towing operation and engine braking operation during the downhill section.

12. The vehicle system of claim 1, wherein the electronic control system is configured to perform one or more of the following operations: (a) operating the electric motor to provide torque during transmission shifting, thereby mitigating power interruption during a shifting event; (b) downshifting either the transmission gear or the electric drive axle gear before reaching a downhill section; and (c) upshifting either the transmission gear or the electric drive axle gear during a downhill section.

13. The vehicle system of claim 1, wherein the electronic control system is configured to drive the prime mover system in response to a driver's acceleration request to accelerate the vehicle system during downhill operation.

14. A method for controlling the operation of a vehicle system, the vehicle system comprising: The power system includes a prime mover system, which includes an electric system, which includes an energy storage system (ESS), power electronic devices operatively connected to the ESS, and electric motors operatively connected to the power electronic devices. One or more ground engagement wheels, said one or more ground engagement wheels being operatively connected to said prime mover system; and an electronic control system, said electronic control system being operatively communicable to said prime mover system, said method comprising operating said electronic control system to perform the following actions: Before reaching the downhill section, determine the target vehicle speed, the target state of the power system, and the target vehicle speed for the downhill section. The vehicle system is controlled to achieve the target vehicle speed and target electrical system state before or upon reaching the downhill section. The electrical system is operated to perform electric braking during the downhill section to control vehicle speed according to the downhill vehicle speed target.

15. The method of claim 14, wherein the ESS comprises a battery, and the target state of the power system before the downhill section comprises a target state of charge of the battery, and the method comprises operating the electronic control system to control the ESS to provide the target state of charge of the battery before the downhill section.

16. The method of claim 15, further comprising discharging the battery before the downhill section to achieve the target battery state of charge and increase the available battery system energy storage capacity.

17. The method of claim 14, wherein the power system includes a thermal management system, and the target state of the power system before the downhill section includes a target power system temperature, the method comprising operating the electronic control system to control the thermal management system to provide the target power system temperature before the downhill section.

18. The method of claim 17, wherein one or more of the ESS, the power electronic devices, and the electric machinery are cooled before the downhill section to achieve the target power system temperature, thereby increasing the energy storage capacity of the power system.

19. The method of claim 14, wherein the prime mover system comprises an engine operatively coupled to the one or more ground engagement wheels via a clutch, and the method comprises: The electronic control system is configured to operate the electrical system to perform electric braking concurrently with coasting operations during the downhill section, in which the clutch is disengaged to disengage the engine from the ground engagement wheel.

20. The method of claim 14, comprising: During electric braking on the downhill section, the operation of the electric motor is switched back and forth between peak power operation and continuous power operation to control the vehicle speed according to the downhill vehicle speed target.

21. The method of claim 14, comprising: The electronic control system is operated to prevent charging of the ESS from the power electronics, and the engine is operated to apply a load to the electric motor to control the vehicle speed according to the downhill vehicle speed target.

22. The method of claim 14, comprising: The electronic control system is operated to prevent charging of the ESS from the power electronics, and the engine is operated to apply loads to one or more ground engagement wheels to control the vehicle speed according to the downhill vehicle speed target.

23. The method of claim 14, further comprising operating the electronic control system to: Determine the target gliding speed of the vehicle system on a portion of the downhill section; and When the vehicle system reaches the portion of the downhill section, it accelerates toward the gliding target by one of the following operations: Perform one of the following operations: engine reversing, coasting in neutral, or coasting with the engine off. Operate the electric motor to reduce the amount of electric braking.

24. The method of claim 14, wherein the prime mover system comprises an engine, and the method comprises: The electronic control system is operated to operate the electrical system, thereby performing electric braking concurrently with either engine-assisted reversing or engine braking during the downhill section.

25. The method of claim 14, comprising one or more of the following: (a) operating the electric motor to provide torque during a gear shift, thereby mitigating power interruption during a shift event; (b) downshifting either the gearbox gear or the electric drive axle gear before reaching a downhill section; and (c) upshifting either the gearbox gear or the electric drive axle gear during a downhill section.

26. The method of claim 14, wherein the prime mover system comprises a series hybrid power system including an engine operatively coupled to the electric motor, and the method comprises operating the electronic control system in response to a driver acceleration request to drive the prime mover system to accelerate the vehicle system during downhill operation.

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