Method and system for operating an electric vehicle under off-road conditions
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- GM GLOBAL TECHNOLOGY OPERATIONS LLC
- Filing Date
- 2022-09-14
- Publication Date
- 2026-07-23
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
INTRODUCTION Commercially available vehicles suitable for off-road operation with electric vehicle (EV) powertrains are being introduced. A vehicle with an EV powertrain can operate in off-road conditions where access to charging systems may be limited. Operating an EV on unpaved roads presents new challenges in terms of electrical energy consumption and management. In an off-road environment, there may be fewer charging stations and a higher likelihood of mobile connectivity being unavailable compared to an urban or highway environment. In addition, road conditions may require powertrain operating characteristics that consume a significant amount of electrical energy, such as in an off-road mode.There is a risk that the electrical charge in the EV's battery will enter a low battery voltage state in a location far from a charging station and without communication capability. There is a need for an EV control system that can learn characteristics of an off-road path based on sensor data from other vehicles that have traveled the same path to dynamically control navigation on an off-road path for efficient energy consumption. There is a need for an EV control system that can dynamically control the operation of the EV powertrain and other in-vehicle systems in the context of the off-road section for efficient energy consumption. There is a need for an EV control system that considers factors such as off-road driving behavior and ambient weather conditions. There is a need for a system capable of suggesting online route changes along the path relative to a battery state of charge to manage energy to avoid a low battery voltage condition at a location remote from a charging station. SUMMARY The concepts described herein include a method and system for dynamically controlling a vehicle including an electric vehicle (EV) powertrain that operates on an off-road path segment in a manner that achieves efficient energy consumption and dynamically controls navigation on the off-road path for efficient electrical energy consumption. According to one embodiment, this includes an operating system for a subject vehicle including an electric vehicle (EV) powertrain and a plurality of electrically powered accessories electrically coupled to a rechargeable DC power source, a navigation system including a Global Navigation Satellite System (GNSS) sensor, and a controller. The controller includes an instruction set in the form of an encoded data file stored in a non-transitory digital data storage medium. The instruction set is executable for determining a target off-road segment via the navigation system and for characterizing the subject vehicle, the environmental conditions, and the target off-road segment to determine an estimated electrical energy consumption for the subject vehicle to operate over the target off-road segment.The EV powertrain and the majority of electrically powered accessories are controlled during operation of the subject vehicle on the off-road segment based on the estimated electrical energy consumption for the subject vehicle. This is done to minimize the likelihood of a low state of charge (SOC) event for the DC power source for the segment and to avoid a low battery voltage condition at a location remote from a charging station. One aspect of the disclosure includes that the instruction set is operable to control the electrical power consumption of the subject vehicle such that a low SOC event for the DC power source is avoided during operation of the subject vehicle on the target off-road path segment. Another aspect of the disclosure includes that the operating parameters of the EV powertrain are a transmission gear state, a limited-slip differential state, and a 2WD / 4WD transfer case state. The instruction set is executable to control the electrical power consumption associated with the transmission gear state, the limited-slip differential state, and / or the 2WD / 4WD transfer case state during operation of the subject vehicle on the off-road trail segment. Another aspect of the disclosure includes that the operating parameters of the plurality of electrically powered accessories are control parameters for an electric steering system, an HVAC system, and / or a stability control system. The instruction set is executable to control the plurality of electrically powered accessories to control the electrical power consumption of the electric steering system, the HVAC system, and / or the stability control system during operation of the subject vehicle on the target off-road segment. Another aspect of the disclosure includes that the instruction set is executable to characterize the topography, terrain, surface conditions, road grade, and accessibility for the target off-road segment. Another aspect of the disclosure includes that the instruction set is operable to characterize the topography, terrain, surface conditions, path gradient, and off-road accessibility for the target path segment based on information previously communicated by other vehicles that have traversed the path segment. Another aspect of the disclosure includes that the instruction set is executable to determine communication points near the target path segment in the terrain. Another aspect of the disclosure includes that the instruction set is executable to determine electrical recharging locations near the target path segment in the terrain. Another aspect of the disclosure includes that the instruction set is operable to determine the current ambient temperature and precipitation and other factors that may affect wheel slip on the target off-road segment. Another aspect of the disclosure includes the instruction set executable to characterize the vehicle operator and estimate the electrical energy consumption for the subject vehicle to operate over the target off-road segment, wherein the estimated electrical energy consumption is determined based on the operating parameters of the EV powertrain and the plurality of electrically powered accessories, the ambient conditions, the target off-road segment, and the characterization of the vehicle operator. Another aspect of the disclosure includes the instruction set executable to determine vehicle mass, tire pressures, and the presence of a towed vehicle and other dynamic factors that affect power consumption. Another aspect of the disclosure includes the instruction set executable to control the EV powertrain and the plurality of electrically powered accessories during operation of the subject vehicle on the off-road segment of travel based on the estimated electrical energy consumption for the subject vehicle. Another aspect of the disclosure includes the instruction set executable to suggest an alternative route based on the estimated electrical energy consumption for the subject vehicle to avoid the occurrence of a low SOC event during operation of the vehicle. Another aspect of the disclosure includes the instruction set executable to identify and recommend an en-route exit to locate a charging station based on the estimated electrical energy consumption for the subject vehicle from the target off-road segment to avoid the occurrence of a low SOC event during operation of the vehicle on the target off-road segment. Another aspect of the disclosure includes the instruction set executable to recommend an alternative route based on the estimated electrical energy consumption for the subject vehicle to avoid the occurrence of a low SOC event during operation of the vehicle on the target off-road path segment. Another aspect of the disclosure includes a method for controlling operation of a subject vehicle including an electric vehicle (EV) powertrain and a plurality of electrically powered accessories electrically coupled to a rechargeable DC power source, and a navigation system including a GNSS sensor. The method includes determining a target off-road segment via the navigation system, determining operating parameters of the EV powertrain and a plurality of electrically powered accessories, characterizing environmental conditions for the target off-road segment, and characterizing the target off-road segment.An electrical energy consumption is estimated for the subject vehicle to operate over the target off-road segment, wherein an estimated electrical energy consumption is determined based on the operating parameters of the EV powertrain and the plurality of electrically powered accessories, the ambient conditions, and the target off-road segment. The EV powertrain and the plurality of electrically powered accessories are controlled during operation of the subject vehicle over the target off-road segment based on the estimated electrical energy consumption for the subject vehicle. The above summary is not intended to represent every possible embodiment or aspect of the present disclosure. Rather, the above summary is intended to illustrate, by way of example, some of the novel aspects and features disclosed herein. The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of representative embodiments and modes of implementation of the present disclosure when taken in conjunction with the accompanying drawings and the claims. Character list One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 schematically illustrates a subject vehicle having an electrified (EV) powertrain according to the disclosure; Fig. 2 schematically illustrates a process for operating an embodiment of the subject vehicle on a target off-road segment according to the disclosure; Fig. 3 schematically illustrates an off-road path characterization process that may be used to characterize an off-road path utilizing information from a topographical map and vehicle-specific information collected by one or more vehicles that have traversed the off-road segment, according to the disclosure; Fig. 4 pictorially illustrates a map of an exemplary target off-road path including a starting point, a plurality of path segments, alternative path segments, and an ending point, according to the disclosure;Figure 5 schematically illustrates a process for dynamically controlling the operation of a vehicle including an EV powertrain and a plurality of electrically powered accessories while traversing a plurality of path segments of a target off-road path, according to the disclosure; Figure 6 schematically illustrates a process for assessing and characterizing operator behavior in the context of the energy consumption of an off-road environment, according to the disclosure. The accompanying drawings are not necessarily to scale and may provide a somewhat simplified illustration of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes. Details associated with such features will be determined in part by the particular intended application and use environment. DETAILED DESCRIPTION The components of the disclosed embodiments, as described and illustrated herein, can be arranged and configured in a variety of different configurations. Thus, the following detailed description is not intended to limit the scope of the disclosure as claimed, but merely represents possible embodiments thereof. Furthermore, although numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments may be practiced without some of these details. Moreover, certain technical material understood in the related art has not been described for clarity to avoid unnecessarily obscuring the disclosure.For convenience and clarity, directional terms such as top, bottom, left, right, upward, over, above, under, below, behind, and in front may be used with reference to the drawings. These and similar directional terms are not intended to limit the scope of the disclosure. Furthermore, the disclosure as shown and described may be practiced in the presence of any element not specifically disclosed herein. As used herein, the term "system" may refer to one or more combinations of mechanical and electrical actuators, sensors, controllers, application-specific integrated circuits (ASICs), combinational logic circuits, software, firmware, and / or other components configured to provide the described functionality. Example embodiments may be described herein in terms of functional and / or logical block components and various processing steps. It will be appreciated that such block components may be implemented by any number, combination, or arrangement of mechanical and electrical hardware, software, and / or firmware components configured to perform the specified functions.For example, an embodiment may utilize various combinations of mechanical components and electrical components, integrated circuit components, memory elements, digital signal processing elements, logic elements, lookup tables, or the like, which may perform a variety of functions under the control of one or more microprocessors or other control devices. Furthermore, those skilled in the art will appreciate that example embodiments may be implemented with any number of mechanical and / or electronic systems, and that the vehicle systems described herein are merely exemplary embodiments of possible implementations. The use of ordinal numbers such as first, second and third does not necessarily imply a ranking, but rather can only distinguish between multiple instances of an action or structure. Referring to the drawings, wherein like reference numerals correspond to like or similar components throughout the several figures, Fig. 1 schematically illustrates one embodiment of a vehicle 100 including an electrified vehicle (EV) powertrain 15 configured to transmit propulsion torque to one or a plurality of wheels using electrified drive units (hereinafter "drive units") that utilize electric machines as prime movers. The EV powertrain 15 of the vehicle 100 may be capable of two-wheel drive (2WD) operation, four-wheel drive (4WD) operation, all-wheel drive (AWD) operation, and / or other powertrain operation within the concepts described herein. The vehicle 100 may include, but is not limited to, a mobile platform in the form of a commercial vehicle, an industrial vehicle, an agricultural vehicle, a passenger vehicle, an aircraft, a watercraft, a train, an off-road vehicle, a passenger moving device, a robot, and the like to fulfill the purpose of this disclosure. According to one embodiment, the EV powertrain 15 includes a first drive unit 20, a second drive unit 30, and a third drive unit 40. A controller 14 is configured to control the operation of the EV powertrain 15. Operation of this embodiment of the vehicle 100 includes controlling the EV powertrain 15 as described herein. The drive wheels shown are non-limiting examples and include a first, front axle 11 with steerable front wheels 17 and a second, rear axle 13 with fixed rear wheels 18. The front wheels 17 are mechanically coupled to a first drive unit 20, which includes a first electric machine 22 coupled to the front wheels 17 via a first drivetrain 25, which, according to one embodiment, includes a transaxle 26 and half-shafts 28. A first power converter 24 is coupled to the electric machine 22 and is electrically connected to a rechargeable high-voltage DC power source (battery) 10 via a high-voltage bus 12. The controller 14 controls the operation of the first drive unit 20 by controlling the first power converter 24. According to one embodiment, the front wheels 17 are coupled to an electric power steering system 29. According to one embodiment, the rear wheels 18 are mechanically coupled to the second drive unit 30 and to the third drive unit 40. The second drive unit 30 includes a second electric machine 32 coupled to a first of the rear wheels 18 via a second drivetrain 35, which according to one embodiment includes a differential 36 and a halfshaft 37. A second power converter 34 is coupled to the second electric machine 32 and is electrically connected to the battery 10 via the high-voltage bus 12. The controller 14 controls the operation of the second drive unit 30 by controlling the second power converter 34. The third drive unit 40 includes a third electric machine 42 coupled to a second of the rear wheels 18 via a third drivetrain 45, which according to one embodiment includes a differential 46 and a halfshaft 47.A third power converter 44 is coupled to the third electric machine 42 and is electrically connected to the battery 10 via the high-voltage bus 12. The controller 14 controls the operation of the third drive unit 40 by controlling the third power converter 44. Battery 10 is coupled to the first, second, and third drive units 20, 30, 40 via high-voltage bus 12. According to one embodiment, battery 10 is a multi-cell lithium-ion device capable of repeated charging and discharging under a range of conditions. The illustrated arrangement of the EV powertrain 15 is shown for illustrative purposes, and the arrangement of the wheels and drive units is a non-limiting embodiment. It will be appreciated that the concepts described herein may also be applied to EV powertrain configurations including one, two, three, or four electric machines and corresponding drivetrains and power converters. The concepts described herein may be applicable to various configurations and EV powertrains and EV systems having one or more electric drive units capable of operating to transfer propulsion torque to the front wheels 17 and to the rear wheels 18, utilizing electric power as the power source. The vehicle 100 includes an electrically operated steering system 29 for controlling the steerable wheels, e.g., the front wheels 17. The EV powertrain 15 may include a transmission and / or a limited-slip differential and / or a 2WD / 4WD transfer case with an electrically driven hydraulic pump. Operation of the EV powertrain 15 includes controlling a transmission gear state and / or a limited-slip differential state and / or a 2WD / 4WD transfer case state. The vehicle 100 has an air conditioning system 29 that includes an electrically operated heating, ventilation, and air conditioning (HVAC) compressor and a fan system. The vehicle 100 includes an electrically operated stability control system 23 that includes controllable suspension actuators 27 located at the corners of the vehicle 100. Vehicle parameters can be determined from sensor measurements, sensor estimates, and sensor perceptions received by a sensor system in the form of an inertial measurement unit (IMU) 51 that communicates with the stability control system 23. Non-limiting examples of vehicle parameters include longitudinal acceleration, lateral acceleration, yaw rate, steering angle, individual wheel speeds, longitudinal speed, lateral speed, tire forces (lateral, normal), vehicle mass, road surface coefficient, upcoming road curvature, and / or upcoming road obstacles.The vehicle stability control system 23 controls the suspension actuators 27 located at each of the corners of the vehicle 100 in a manner that maintains vehicle stability on-road and during off-road excursions. The vehicle 100 includes a telematics device 48 that includes a wireless telematics communication system capable of off-vehicle communications, including communications with a communications network system having wireless and wired communication capabilities. The telematics device 48 is capable of off-vehicle communications that include short-range ad-hoc vehicle-to-vehicle (V2V) communication and / or vehicle-to-everything (V2x) communication, which may include communications with an infrastructure monitor, e.g., a traffic camera, and ad-hoc vehicle communication. Alternatively or additionally, the telematics device 48 includes a wireless telematics communication system capable of short-range wireless communication with the handheld device 49, e.g., a cellular phone, a satellite phone, or other telephony device.According to one embodiment, a software application is loaded into the handheld device 49, including a wireless protocol for communicating with the telematics device 48 to effect identification of the vehicle operator. According to one embodiment, the handheld device 49 performs the off-vehicle communication, including communicating with an external server 59 via a communications network 90 including a satellite 80, an antenna 85, and / or another communication mode. Alternatively or additionally, the telematics device 48 performs the off-vehicle communication directly by communicating with the external server 95 via the communications network 90. According to one embodiment, the external server 95 is cloud-based. The vehicle 100 includes a navigation system 55 that includes a computer-readable storage device or computer-readable storage media (memory) containing a digitized road map, a Global Navigation Satellite System (GNSS) sensor 53, and a human-machine interface (HMI) device for interacting with and operating the navigation system 55. The GNSS sensor 53 generates a set of parameters corresponding to the vehicle's speed, geospatial position, and vehicle heading. The concepts described herein may be used in various systems that may utilize information determined by an embodiment of a spatial monitoring system 41 in a manner described herein. The vehicle 100 has a first plurality of sensors 50 that include sensors configured to dynamically monitor in-vehicle operating conditions, including, for example, vehicle speed, vehicle acceleration, braking, steering angle, yaw rate, tire pressures, vehicle mass, trailer presence, battery state of charge (SOC), operator requirements, etc. The first plurality of sensors 50 includes the GNSS sensor 53 and the inertial measurement unit (IMU) 51. The IMU 51 is an electronic device that utilizes one or more of a combination of accelerometers, gyroscopes, and magnetometers configured to measure and report vehicle dynamic parameters, such as specific force, angular rate, yaw, and orientation of the vehicle 100. The vehicle 100 includes a second plurality of sensors 52 that includes sensors configured to dynamically monitor environmental conditions, including, for example, altitude, ambient pressure, ambient temperature, humidity (dew point), precipitation, time of day, solar exposure, etc. Alternatively or additionally, some of the environmental conditions may be obtained through connectivity with a remote weather station or with other vehicles using V2X communications via the telematics system 60. The vehicle 100 includes a third plurality of sensors 54 associated with the spatial monitoring system 41, which are configured to provide spatial monitoring in the vicinity of the subject vehicle 100. The spatial monitoring system 41 may be an element of an advanced driver assistance system (ADAS) 39. The fourth plurality of sensors 54 may include, for example, a camera, a radar sensor, a lidar sensor, etc. Parameters associated with spatial monitoring include the presence and location of other nearby vehicles, the presence and location of stationary objects that may serve as obstacles (e.g., rocks, trees, fences, guardrails, etc.), the presence and location of pedestrians, cyclists, animals, etc. The term "controller" and related terms such as microcontroller, controller, control unit, processor, etc. refer to one or various combinations of one or more application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), electronic circuits, central processing units, e.g., microprocessors, and associated non-transitory memory components in the form of digital data storage media, including memory and storage devices (read-only, programmable read-only, read-write, hard disk drive, etc.).The non-transitory memory component is capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, one or more combinational logic circuits, one or more input / output circuits and input / output devices, signal conditioning, buffer circuitry, and other components accessible and executable by one or more processors to provide described functionality. The one or more input / output circuits and input / output devices include analog-to-digital converters and associated devices that monitor inputs from sensors, such inputs being monitored at a preset sampling frequency or in response to a trigger event.Software, firmware, programs, instructions, control routines, code, algorithms, and similar terms mean sets of instructions executable by a controller, including calibrations and lookup tables. Each controller executes one or more control routines to provide desired functions. Routines may be executed at regular intervals, e.g., every 100 microseconds during continuous operation. Alternatively, routines may be executed in response to the occurrence of a trigger event. Communication between controllers, actuators, and / or sensors may be achieved using a direct-wired point-to-point link, a networked communication bus link, a wireless link, or another communication link. Communication includes the exchange of data signals, including, for example,electrical signals over a conductive medium; electromagnetic signals over air; optical signals over fiber optics; etc. The data signals may include discrete, analog, and / or digitized analog signals representing inputs from sensors, actuator commands, and communication between controllers. The term “signal” refers to a physically distinguishable indicator that conveys information and may be any suitable signal form (e.g., electrical, optical, magnetic, mechanical, or electromagnetic) such as DC, AC, sine wave, triangular wave, square wave, vibration, and the like that is capable of propagating through a medium. The term 'model' refers to a processor-based or processor-executable code and associated calibration that simulates a physical existence of a device or physical process. As used herein, the term 'dynamic' and related terms describe steps or processes that are executed in real time and are characterized by monitoring or otherwise determining states of parameters and regularly or periodically updating the states of the parameters during execution of a routine or between iterations of execution of the routine. The terms "calibration," "calibrated," and related terms refer to a result or process that correlates a desired parameter and one or more perceived or observed parameters for a device or system. Calibration, as described herein, may be represented by a storable parametric table, a set of executable equations, or another suitable form that can be used as part of a measurement or control routine. A parameter is defined as a measurand that represents a physical property of a device or other element that is perceivable using one or more sensors and / or a physical model. A parameter can have a discrete value, e.g., either "1" or "0," or its value can be infinitely variable. Fig. 2 schematically illustrates a process 200 for operating an embodiment of the subject vehicle 100 described with reference to Fig. 1 on a target off-road path 210. The process 200 includes dynamically controlling the EV powertrain 15 and the plurality of electrically powered accessories to minimize or optimize electrical energy consumption by the subject vehicle 100 during operation on the target off-road path 210. The target off-road path 210 may be composed of one or a plurality of path segments 212, 213, 214, etc. Non-limiting examples of the target off-road path 210 and the plurality of path segments 212, 213, 214, etc. are pictorially illustrated and described with reference to Fig. 4. The process 200 includes identifying the target off-road path 210 (step 205); characterizing the target off-road path 210 (step 220); acquiring and evaluating one or more characterizations of the target off-road path 210 to determine optimal control states for the EV powertrain 15 and for the plurality of electrically powered accessories of the subject vehicle 100 based on energy consumption (steps 230, 235); and dynamically controlling the operation of the EV powertrain 15 and the plurality of electrically powered accessories as the subject vehicle 100 traverses the plurality of path segments 212, 213, 214, etc. of the target off-road path 210 in a manner that optimizes electrical energy consumption by the subject vehicle 100 (step 240). The process 200 for operating the subject vehicle 100 to dynamically control the EV powertrain 15 and the plurality of electrically powered accessories includes identifying the target off-road path 210 (step 205) and is based on characterizations of the target off-road path 210 (step 220). The process 200 may be implemented by a computer algorithm, by machine-executable code, by a non-transitory computer-readable medium, or by software instructions programmed into one or more suitable programmable logic devices of the subject vehicle 100, such as the controller 14, the external server 95 in communication with the controller 14, a mobile device in communication with the controller 14 and / or with the external server 95, another controller in the subject vehicle 100, or a combination thereof. Although the various steps shown in the flowchart appear to occur in a chronological order, at least some of the steps may occur in a different order, and some steps may be performed concurrently or not at all. In operation, the controller 14 identifies or otherwise determines the target off-road path 210, which includes the plurality of path segments 212, 213, 214, etc. (step 205). The target off-road path 210 may be identified when the operator directs the subject vehicle 100 to the target off-road path 210, when the operator inputs the target off-road path 210 into the on-board navigation system 55, or through another mechanism. Information relating to the operation of the subject vehicle 100 on the target off-road path 210 is collected for each of the plurality of path segments 212, 213, 214, etc. (step 220). The collected information includes information relating to or influencing an estimated electrical energy consumption for the subject vehicle 100 while traveling the target off-road path 210. The information collection process (step 220) includes collecting trip data (step 222), collecting context data associated with vehicle operation on the target off-road path 210 (step 224), collecting terrain data for the plurality of path segments 212, 213, 214, etc., of the target off-road path 210 (step 226), and collecting in-vehicle sensor data for the plurality of path segments 212, 213, 214, etc., of the target off-road path 210 (step 228). The steps of the information collection process (step 220) are executed periodically, e.g., once per second, to collect data for storage, analysis, and transmission. The trip data (step 222) includes the travel distance, elapsed time, and electric power consumption (kWh) for each of the path sections 212, 213, 214, etc., of the target off-road path 210. The trip data is collected each time the subject vehicle 100 travels through the target off-road path 210 and each time another connected vehicle travels through the target off-road path 210. The context data associated with vehicle operation on the target off-road path 210 (step 224) includes ambient weather conditions, e.g., precipitation, temperature, snow depth, ice, standing water, etc., and other factors that affect vehicle traction and the vehicle energy expected to be consumed to traverse the target off-road path 210. The context data also includes vehicle information such as vehicle mass, HVAC load, the presence of a trailer, and other factors that affect the vehicle energy consumed to traverse the target off-road path 210. The context data also includes wireless connectivity for communication and the location and accessibility of nearby charging stations relative to the target off-road path 210. The terrain data for the plurality of path sections 212, 213, 214, etc. of the target off-road path 210 (step 226) includes data relating to topography, terrain, surface conditions, path gradient, and other factors that may affect an estimated electrical energy consumption for the subject vehicle 100 while traversing the target off-road path 210. The sensor data for the plurality of path segments 212, 213, 214, etc. of the target path 210 in the terrain (step 228) includes data collected by the third plurality of sensors 54 that detect the presence and location of other nearby vehicles, the presence and location of stationary objects that may serve as obstacles (e.g., rocks, trees, fences, guardrails, etc.), the presence and location of pedestrians, cyclists, animals, etc. The information including the trip data, the context data, the terrain data, and the sensor data for the target path 210 in the terrain, which are collected during each trip by the information collection process (step 220), is transmitted via the communication network 90 to a database 232, which may be located at the external server 95 (step 225). As described with reference to Fig. 3, the information including the trip data, the context data, the terrain data, and the sensor data for the target path 210 in the terrain is used to characterize the target path 210 in the terrain. Fig. 3 schematically illustrates a terrain path characterization process 300 that may be used to characterize a terrain path using information from a topographical map and vehicle-specific information collected by one or more vehicles that have traversed the terrain path. The terrain path characterization process 300 is described with reference to an embodiment of the subject vehicle 100 described with reference to Fig. 1 and the target terrain path 210 described with reference to Figs. 2 and 4.The information including the trip data, the context data, the terrain data, and the sensor data for the target off-road path 210 is obtained via the first plurality of sensors 50 configured to dynamically monitor in-vehicle operating conditions, the second plurality of sensors 52 configured to dynamically monitor environmental conditions, and the third plurality of sensors 54 configured to provide spatial monitoring in the vicinity of the subject vehicle 100. The terrain path characterization process 300 performs end-to-end training to characterize the terrain section to train the complete system end-to-end using consecutive frames of all available data. Each sensor frame from all available censors passes through a convolutional neural network (CNN) 305 as a feature extraction backbone (e.g., ResNet), and the model 330 uses a recurrent neural network (RNN) to account for temporal information. The inputs to the terrain path characterization process 300 include inputs from each of the first plurality of sensors 50 and each of the third plurality of sensors 54 and corresponding locations from the GNSS sensor 53. The inputs also include a topographic map 301, vehicle dynamics information from the IMU 51, and ambient weather conditions derived from the second plurality of sensors 52. The inputs from each of the first plurality of sensors 50 and each of the third plurality of sensors 54 are individually passed for each time step as a feature extraction backbone (e.g., Resnet) via a convolutional neural network (CNN) 305. The aforementioned inputs are subjected to an integration process 320 to determine an integral 325. The integral 325 is subjected to a recurrent neural network (RNN) (step 330) to account for temporal information, thus resulting in a characterization score 335 for the target off-road path 210. The characterization score 335 for the target off-road path 210 represents the energy consumption for each data point on the target off-road path 210. This information can be used to determine a powertrain configuration that minimizes energy consumption based on the section characterization. This can be achieved using regression techniques (continuous variable prediction techniques), e.g., a decision tree regression, linear regression, a random forest regression, a neural network, etc.The input data contains details of the powertrain configuration, as described, for example, in Fig. 1. The output is energy consumption. The values (weights) in the model are the parameters that should be assigned to the powertrain elements. Referring again to Fig. 2, the characterization score 335 for the target off-road path 210 is input into an optimization routine 234, which determines an optimal powertrain configuration (step 235) for each path segment to achieve efficient energy consumption. The optimal powertrain configuration determined by step 235 for each path segment is transmitted to the respective vehicle 100. The subject vehicle 100 utilizes the optimal powertrain configuration (step 235) to achieve efficient energy consumption for each path segment to determine optimal control states for the EV powertrain 15 and the plurality of electrically powered accessories of the subject vehicle 100. The optimal powertrain configuration (step 235) is communicated to the subject vehicle 100, which dynamically controls the operation of the EV powertrain 15 and the plurality of electrically powered accessories in a manner that optimizes electrical energy consumption while traversing the plurality of path segments 212, 213, 214, etc., of the target path 210 off-road (step 240). Elements of this operation are described in additional detail with reference to Fig. 5. Fig. 4 pictorially shows a map of an exemplary destination path 210 in the terrain, including a starting point 211, a plurality of path segments 212, 213, 214, 215, and 216, alternative path segments 213A and 215A, and an end point 219. Also indicated is an exit point 217, which includes an exit path segment 218 leading to a charging station 218A. The destination path 210 in the terrain may be included in the topographic map 301 described with reference to Fig. 3. Alternate path segments 213A and 215A are alternative paths available along off-road path 210 that offer lower or more efficient energy consumption when needed. Based on the battery SOC and predicted power consumption, during off-road driving, vehicle controller 14 may suggest operation on alternate path segments, e.g., alternate path segments 213A and 215A, that may be suboptimal in terms of connectivity and visibility, but that modify the powertrain configuration to reduce energy consumption such that the available battery power is sufficient to traverse off-road path 210 from starting point 211 to ending point 219. Fig. 5 schematically illustrates a process 500 for dynamically controlling the operation of the EV powertrain 15 and the plurality of electrically powered accessories as the subject vehicle 100 traverses the plurality of path sections 212, 213, 214, etc. of the target path 210 in the off-road environment. During operation of the subject vehicle 100 on the target off-road path 210 (502), on-road monitoring is performed (504) to determine the actual energy consumption by the subject vehicle 100. The actual energy consumption by the subject vehicle 100 is compared to an expected energy consumption by the subject vehicle 100 for the path sections 212, 213, 214, etc., of the target off-road path 210. The actual energy consumption by the subject vehicle 100 for one or more of the path sections 212, 213, 214, etc., of the target off-road path 210 may differ from the expected energy consumption by the subject vehicle 100 due to changes in ambient weather conditions, operator behavior, and other factors. A low energy risk assessment is updated based on the actual energy consumption by the vehicle 100 in question for the respective path section and the expected energy consumption by the vehicle 100 in question due to changes in ambient weather conditions, operator behavior, and other factors (506) and compared with an initial low energy risk assessment determined prior to the actual operation of the vehicle 100 in question on the target path 210 in the field (508) If the updated low-energy risk assessment is greater than the initial low-energy risk assessment (510), this indicates an increased likelihood that the subject vehicle 100 will experience a low-energy event en route in the form of a low SOC event for the battery 10, which poses an increased risk to the vehicle operator. In this case, recommendations may be made to the vehicle operator, including recommending changes to the operator's driving behavior (less aggressive), recommending alternative route paths, e.g., alternative route sections 213A and 215A described with reference to FIG. 4, and / or recommending changing exit points, e.g., recommending exit point 217, which includes an exit route section 218 leading to a charging station 218A described with reference to FIG.4, to reduce the risk of a low energy event along the route. In this way, alternative paths along the route can be suggested as needed based on the battery SOC and predicted energy consumption for more efficient energy consumption. The off-road routing may be suboptimal in terms of connectivity and view, but based on the changes in powertrain configuration, it reduces energy consumption and ensures that there is sufficient energy to operate the vehicle 100 throughout the entire route. If there is higher than expected energy consumption, increasing the risk of a low SOC event for the battery 10, the system can suggest exit points along the route to charge the vehicle.If the vehicle is near these exit points, the operator can drive to a charging point, which should be within a reasonable distance, and then choose whether to return to the route. The risk of a low SOC event for the battery 10 due to energy consumption in the off-road area can be exacerbated by factors such as the absence of nearby charging stations, poor connectivity (i.e., no one can be called to indicate that towing services are necessary), a muddy surface due to weather, etc. In some cases, an acceptable low battery voltage limit state can be determined by the user and limited by absolute levels for the low energy limit state associated with causing irreversible damage to the battery 10. If the updated low energy risk assessment is less than the initial low energy risk assessment (512), this indicates an increased probability that the subject vehicle 100 will experience a low SOC event for the battery 10 en route. This information may be provided as feedback to the vehicle operator. Fig. 6 schematically illustrates a process 600 for assessing and characterizing operator behavior in the context of energy consumption in an off-road environment. The process 600 includes capturing operator behavior for an identified operator while operating on multiple trips under off-road conditions in the subject vehicle 100 (602). The captured operator behavior includes off-road driving techniques related to handling various conditions such as uphill / downhill gradients, hill climbing, snow, sand, mud, rivers / streams, etc., when the monitored operator behavior includes inputs to the accelerator pedal, brake pedal, gear selection, powertrain selection, steering commands, etc. (604). The characterization process generates a driving score (606) that reflects how much the operator behavior contributes to energy consumption.As non-limiting examples, a positive rating may reflect operator behavior that reduces energy consumption compared to expected energy for a typical off-road path, with an increase in the magnitude of the positive rating reflecting a greater reduction in energy consumption due to operator behavior. Similarly, a negative rating may reflect operator behavior that increases energy consumption compared to expected energy consumption for a typical off-road path, with an increase in the magnitude of the negative rating reflecting a greater increase in energy consumption due to operator behavior. Providing a rating for off-road ride quality in terms of energy consumption may be achieved using regression techniques.This feature ranking of the model inputs and the understanding of which elements of off-road driving technique contribute more to energy consumption are used to provide feedback and tips to the driver on how to improve energy consumption. The driving score generated by step 606 may be used during subsequent operation by the operator when operating on an off-road trail to adjust the estimated trail energy consumption (610). Additionally, the driving score generated by step 606 can be used to generate and provide recommendations to the operator (608) regarding driving techniques that can be used to reduce energy consumption and improve operating efficiency. This includes developing an understanding of which elements of off-road driving technique contribute more to energy consumption. This serves to provide feedback and tips to the driver on how to improve energy consumption. The flowchart and block diagrams in the flowcharts illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, section, or portion of code comprising one or more executable instructions for implementing the one or more specified logical functions. It is also noted that each block of the block diagrams and / or flowchart representations and combinations of blocks in the block diagrams and / or flowchart representations may be implemented by hardware-based systems having dedicated functions that perform the specified functions or acts, or by combinations of hardware having dedicated functions and computer instructions.These computer program instructions may also be stored in a computer-readable medium that can instruct a computer or other programmable data processing apparatus to function in a particular manner such that the instructions stored in the computer-readable medium produce an article of manufacture that includes an instruction set that implements the function / act specified in the flowchart and / or in the one or more block diagram blocks. The detailed description and the drawings or figures are provided to support and describe the present teachings, but the scope of the present teachings is defined solely by the claims. While some of the best modes and other embodiments of the present teachings have been described in detail, various alternative designs and embodiments exist for practicing the present teachings as defined in the claims.
Claims
An operating system for a subject vehicle, the operating system comprising: an electric vehicle (EV) powertrain and a plurality of electrically powered accessories electrically coupled to a rechargeable DC power source; a navigation system including a Global Navigation Satellite System (GNSS) sensor; and a controller including an instruction set stored as an encoded data file in a non-transitory digital data storage medium, the instruction set executable to: determine, via the navigation system, a target off-road segment; determine operating parameters of the EV powertrain and the plurality of electrically powered accessories; characterize environmental conditions for the target off-road segment; characterize the target off-road segment;Estimating an electrical energy consumption for the subject vehicle for operation over the target off-road segment, wherein an estimated electrical energy consumption is determined based on the operating parameters of the EV powertrain and the plurality of electrically powered accessories, the ambient conditions, and the target off-road segment; and controlling the EV powertrain and the plurality of electrically powered accessories during operation of the subject vehicle over the target off-road segment based on the estimated electrical energy consumption for the subject vehicle. The operating system of claim 1, wherein the set of instructions executable to control the EV powertrain comprises the set of instructions executable to control the electric power consumption of the subject vehicle such that a low state of charge (SOC) event for the DC power source is avoided during operation of the subject vehicle on the target off-road path segment. The operating system of claim 1, wherein the operating parameters of the EV powertrain include a transmission gear state, a limited-slip differential state, and a 2WD / 4WD transfer case state; and wherein the set of instructions executable to control the EV powertrain comprises the set of instructions executable to control the consumption of electrical power associated with at least one of the transmission gear state, the limited-slip differential state, and the 2WD / 4WD transfer case state during operation of the subject vehicle on the target off-road segment. The operating system of claim 1, wherein the operating parameters of the plurality of electrically powered accessories comprise control parameters for at least one of an electric steering system, an HVAC system, and a stability control system; and wherein the command set is executable to control the electrical power consumption of at least one of the electric steering system, the HVAC system, and the stability control system during operation of the subject vehicle on the target off-road segment. The operating system of claim 1, wherein the set of instructions executable to characterize the target off-road segment comprises the set of instructions executable to characterize the topography, terrain, surface conditions, road gradient, and accessibility for the target off-road segment. The operating system of claim 5, wherein the set of instructions executable to characterize the target off-road segment further comprises the set of instructions executable to characterize the topography, terrain, surface conditions, path gradient, and accessibility for the target off-road segment based on information previously communicated by other vehicles that have traversed the target off-road segment. The operating system of claim 1, wherein the instruction set executable to characterize the target path segment in the terrain comprises the instruction set executable to determine communication points in the vicinity of the target path segment in the terrain. The operating system of claim 1, wherein the set of instructions executable to characterize the target path segment in the terrain comprises the set of instructions executable to determine electrical recharging locations in the vicinity of the target path segment in the terrain. The operating system of claim 1, wherein the set of instructions executable to characterize the environmental conditions comprises the set of instructions executable to determine the current ambient temperature and the current precipitation associated with the target path segment in the terrain. The operating system of claim 1, further comprising the instruction set executable to recommend an alternative route based on the estimated electrical energy consumption for the subject vehicle to avoid the occurrence of a low SOC event for the DC power source during operation of the subject vehicle on the target off-road segment.