Tire wear management for vehicles

Abstract

The invention relates to tire wear management for vehicles. Specifically, a computer system for determining a vehicle motion profile is disclosed, the computer system comprising processing circuitry configured to: obtain information relating to an upcoming vehicle path, including a range of the vehicle path; and determining a vehicle motion profile as a solution to an optimization problem that describes a total cost of the vehicle following the vehicle path, including a first cost associated with energy usage of the vehicle and a second cost associated with tire wear of the vehicle; wherein the total cost associated with the solution of the optimization problem is below a threshold; and the determined vehicle motion profile satisfies a range of vehicle paths.

Description

Technical Field

[0001] The present disclosure generally relates to vehicle control. In particular aspects, the present disclosure relates to tire wear management for vehicles. The present disclosure may be applied to heavy-duty vehicles such as trucks, buses, and construction equipment. Specifically, the present disclosure may be applicable to multi-unit vehicle combinations with distributed propulsion and energy storage devices. Although the present disclosure may be described with respect to a specific vehicle, the present disclosure is not limited to any particular vehicle. Background Art

[0002] Many vehicles today use a vehicle motion profile designed to meet specific goals without regard for tire wear. For example, predictive energy management, which controls vehicle motion by optimizing torque (or power) distribution between different power sources and brakes, taking into account upcoming road and traffic conditions, can aim to improve efficiency and range. This can include actions such as regenerative braking, which aims to improve energy efficiency.

[0003] However, some strategies for improving energy efficiency, such as regenerative braking, involve increasing the axial torque on the vehicle's wheels, thereby causing increased tire wear. In this case, the benefits of energy efficiency will be surpassed by the negative impact of tire wear at a certain point.

[0004] It would therefore be desirable to develop a solution for vehicle motion management that would address or at least alleviate some of these issues. Summary of the Invention

[0005] The present disclosure provides systems, methods, and other means for determining a vehicle motion profile such that the costs of different considerations, including tire wear, are adequately balanced. Specifically, information related to an upcoming vehicle path is obtained, including a range of the path. A solution to an optimization problem, such as a nonlinear optimal control problem (NOCP), is formulated involving the total cost of the vehicle following the vehicle path, including costs associated with the vehicle's energy usage and costs associated with tire wear of the vehicle. A solution to the optimization problem is found such that the total cost is below a threshold and the range of the path is satisfied. The solution is then implemented as a vehicle motion profile such that the vehicle follows the vehicle path, meaning that the costs of different considerations, including energy usage and tire wear, are adequately balanced when the vehicle follows the path.

[0006] According to a first aspect of the present disclosure, a computer system for determining a vehicle motion profile is provided, the computer system comprising processing circuitry configured to: obtain information related to an upcoming vehicle path, including a range of the vehicle path, and determine the vehicle motion profile as a solution to an optimization problem describing a total cost of the vehicle following the vehicle path, including a first cost associated with energy usage of the vehicle and a second cost associated with tire wear of the vehicle, wherein the total cost associated with the solution to the optimization problem is below a threshold, and the determined vehicle motion profile satisfies the range of the vehicle path.

[0007] A first aspect of the present disclosure may seek to provide a computer system that balances tire wear and a vehicle's energy usage when planning a motion profile for a trip. The costs associated with energy usage and tire wear can be conflicting, meaning that reducing one cost may result in an increase in the other, depending on the vehicle, control strategy, and road. By determining a motion profile that ensures the total cost associated with energy usage and tire wear is below a threshold, the vehicle's operation can be ensured to not exceed the cost while following the route. This means that different and potentially conflicting considerations, particularly energy usage and tire wear, are adequately balanced during the trip.

[0008] Optionally, in some examples, including at least one preferred example, the vehicle path represents the entire trip of the vehicle from the starting location to the destination location. Technical benefits may include the ability to determine a motion profile for the entire trip, meaning that energy use and tire wear can be adequately balanced beyond the transient or short-term maneuvers typically handled by vehicle motion management systems. If these considerations are not accounted for throughout the trip, the vehicle's range may be reduced.

[0009] Optionally, in some examples, including at least one preferred example, the information related to the upcoming vehicle path includes a friction profile, curvature, and / or vertical profile of the vehicle path. Technical benefits may include determining a vehicle motion profile that takes into account various parameters of the vehicle path, ensuring that both global and local factors throughout the route are considered when balancing energy use and tire wear.

[0010] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to implement the range of the vehicle path as a constraint of the optimization problem. A technical benefit can include that the range requirement of a particular mission will always be met by the determined vehicle motion profile.

[0011] Optionally, in some examples, including at least one preferred example, the optimization problem is a nonlinear optimal control problem (NOCP). Technical benefits may include improved accuracy, robustness, and flexibility when performing optimization.

[0012] Optionally, in some examples, including at least one preferred example, the first cost represents CO2 emissions and / or electrical energy usage.Technical benefits may include incorporating environmental and efficiency factors of the vehicle into the optimization so that a vehicle motion profile can be determined based on these considerations.

[0013] Optionally, in some examples, including at least one preferred example, the second cost represents particulate emissions from the tires, friction losses from the tires, and / or costs associated with tire maintenance. A technical benefit may include incorporating environmental and performance factors related to the vehicle's tires into the optimization, such that a vehicle motion profile may be determined based on these considerations.

[0014] Optionally, in some examples, including at least one preferred example, the processing circuitry is configured to determine costs associated with particle emissions and / or friction losses from the tires as a function of longitudinal slip associated with the one or more wheels. Technical benefits may include optimization for controllable parameters of the vehicle, meaning that the determined vehicle motion profile can be readily implemented in vehicle controls.

[0015] Optionally, in some examples, including at least one preferred example, the vehicle motion profile includes one or more of the vehicle's speed, the vehicle's trajectory, and the power distribution between the vehicle's drive axles, electric motors, and / or internal combustion engine. Technical benefits may include being able to control the vehicle in a variety of different ways to satisfy the determined vehicle motion profile and provide a desired balance between energy use and tire wear.

[0016] Optionally, in some examples, including at least one preferred example, the processing circuitry is further configured to provide the vehicle motion profile to a control system configured to determine one or more control inputs for the vehicle. A technical benefit may include the vehicle's control system being able to control the vehicle to provide a desired balance between energy usage and tire wear.

[0017] Optionally, in some examples, including at least one preferred example, one or more control inputs are associated with one or more driven axles of the vehicle. Technical benefits may include appropriate control of the driven axles to meet a determined vehicle motion profile where tire wear due to axial torque and / or longitudinal slip is particularly high.

[0018] According to a second aspect of the disclosure, there is provided a vehicle comprising any of the aforementioned computer systems.The second aspect of the disclosure may seek to provide a vehicle that can be operated to balance different and potentially conflicting considerations, in particular energy usage and tyre wear.

[0019] According to a third aspect of the present disclosure, a computer-implemented method for determining a vehicle motion profile is provided, the method comprising: obtaining, by processing circuitry of a computer system, information related to an upcoming vehicle path, including a range of the vehicle path; and determining, by the processing circuitry, the vehicle motion profile as a solution to an optimization problem, the optimization problem describing a total cost of the vehicle following the vehicle path, including a first cost associated with the vehicle's energy usage and a second cost associated with tire wear of the vehicle; wherein the total cost associated with the solution to the optimization problem is below a threshold; and the determined vehicle motion profile satisfies the range of the vehicle path.

[0020] A third aspect of the present disclosure may seek to provide a computer-implemented method for balancing tire wear and a vehicle's energy usage when planning a motion profile for a trip. The costs associated with energy usage and tire wear can conflict with each other, meaning that reducing one cost may result in an increase in the other, depending on the vehicle, control strategy, and road. By determining a motion profile that ensures the total cost associated with energy usage and tire wear is below a threshold, the vehicle's operation while following the route can be ensured to not exceed the cost. This means that different and potentially conflicting considerations, particularly energy usage and tire wear, are adequately balanced during the trip.

[0021] According to a fourth aspect of the present disclosure, there is provided a computer program product comprising program code for performing, when executed by processing circuitry, the computer-implemented method of the third aspect. The fourth aspect of the present disclosure may seek to facilitate configuration of new and / or legacy vehicles via software installation / update to determine a vehicle motion profile that balances different and potentially conflicting considerations, particularly energy usage and tire wear.

[0022] According to a fifth aspect of the present disclosure, there is provided a non-transitory computer-readable storage medium comprising instructions that, when executed by a processing circuit, cause the processing circuit to perform the computer-implemented method of the third aspect. The fifth aspect of the present disclosure may seek to facilitate configuration of new and / or legacy vehicles via software installation / update to determine a vehicle motion profile that balances different and potentially conflicting considerations, particularly energy usage and tire wear.

[0023] The disclosed aspects, examples (including any preferred examples) and / or the appended claims may be appropriately combined with each other, as will be apparent to anyone skilled in the art. Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be apparent to those skilled in the art or recognized by practicing the disclosure as described herein.

[0024] Also disclosed herein are computer systems, control units, code modules, computer-implemented methods, computer-readable media, and computer program products associated with the technical benefits discussed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Examples will be described in more detail below with reference to the accompanying drawings.

[0026] Figure 1 A side view of a vehicle according to an example is schematically shown.

[0027] Figure 2 is a flowchart of a computer-implemented method according to an example.

[0028] Figure 3 is a schematic diagram of a computer system for implementing the examples disclosed herein.

[0029] Like reference numerals refer to like elements throughout the specification. DETAILED DESCRIPTION

[0030] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.

[0031] Many vehicles today operate using vehicle motion profiles designed to meet specific goals without regard to tire wear. For example, predictive energy management (PEM) controls vehicle motion by optimizing torque (or power) distribution between various power sources and brakes, taking into account upcoming road conditions and traffic, typically aiming to minimize energy consumption within the upcoming road. This can include actions such as regenerative braking, which aims to improve energy efficiency. However, some strategies for improving energy efficiency, such as regenerative braking, increase axial torque on the vehicle's wheels, leading to increased tire wear. In these cases, the benefits of energy efficiency are ultimately outweighed by the negative impact of tire wear.

[0032] To address this issue, a system and method for determining a vehicle motion profile are presented. Specifically, a system and method are presented for obtaining information related to an upcoming vehicle path, including a path range. A solution is found that describes the total cost of the vehicle following the path, including costs associated with the vehicle's energy usage and costs associated with tire wear. A solution is found such that the total cost associated with the solution is below a threshold and satisfies the path range. This solution is a vehicle motion profile that can be implemented to control the vehicle and ensure that the costs of various considerations, including energy usage and tire wear, are adequately balanced.

[0033] Figure 1A side view of an example vehicle 100 of the type contemplated by the present disclosure is schematically shown. Vehicle 100 may be any suitable type of vehicle. For example, the present disclosure may be applicable to heavy-duty vehicles (such as trucks, buses, construction equipment, and multi-unit vehicle combinations), personal vehicles (such as cars, vans, or motorcycles), or any other suitable type of vehicle. Vehicle 100 includes a plurality of axles, each typically having two or more wheels 110. While three axles are shown, it should be understood that any suitable number of axles may be provided. It should also be understood that any number of the axles may be driven axles.

[0034] Vehicle 100 may include one or more propulsion sources. For example, vehicle 100 may include one or more electric motors 120, such as electric motors and / or generators. Vehicle 100 may include one or more batteries (not shown) configured to provide power to electric motors 120. In some examples, vehicle 100 may also include another propulsion source, such as an internal combustion engine (ICE). Vehicle 100 also includes a drivetrain (not shown) to deliver mechanical power from the propulsion source (electric motors 120 or ICE) to wheels 110.

[0035] The electric motor 120 is configured to drive one or more axles or individual wheels 110 of the vehicle 100, for example, to provide torque and / or steering thereto. The electric motor 120 can supply positive force (propulsion) or negative force (braking). Using the electric motor 120 to supply negative force is referred to as regenerative braking; in this case, the electric motor 120 can operate as a generator to recover energy during braking.

[0036] Furthermore, vehicle 100 may include one or more service brakes 130. Service brakes 130 can provide negative force (braking force). Service brakes 130 can be, for example, friction brakes, such as pneumatic brakes. Pneumatic brakes use a compressor to inflate the brakes, which can be powered by a battery. In some examples, the brakes can be electromechanical brakes. Energy recovered from regenerative braking by motor 120 can be stored in the battery, and therefore regenerative braking can generally be preferred to using the service brakes.

[0037] In some examples, vehicle 100 may be a vehicle combination comprising multiple units, including a tractor unit and at least one trailer unit. The tractor unit is typically the front-most unit in the vehicle combination and may include a driver's cab (including steering controls, instrument panel display, etc.). Generally, the tractor unit is used to provide propulsion for the vehicle combination 100. The trailer unit is typically used to store the cargo being transported by the vehicle combination 100. The trailer unit may be a truck, trailer, dolly, etc. The trailer unit may also provide propulsion for the vehicle combination 100. In such an example, each unit may include its own motor 120, battery, service brake 130, etc. In this way, all units can provide propulsion for the vehicle combination 100.

[0038] As the vehicle 100 moves, the wheels (or indeed tires) 110 of the vehicle 100 experience slip. Slip can manifest as body slip of the vehicle 100 as a whole, or can manifest as slip of a given wheel 110, which can be categorized as longitudinal slip and lateral slip. These parameters are known in the art and will not be discussed in detail here. However, it is noted that longitudinal slip on a wheel 110 is and lateral slip It can be given by: in is the tire radius, is the wheel speed, and is the hub velocity component in the local wheel coordinate system, for the wheel index, and The unit index in case of a multi-unit vehicle combination.

[0039] return Figure 1 , the vehicle 100 includes a controller 140 that includes a processing circuit 150. The controller 140 is configured to control components of the vehicle, such as the motor 120. Figure 1 A common controller 140 is shown for all motors 120 of vehicle 100, however, it should be understood that each motor 120 may have its own corresponding controller 140. In many cases, controller 140 may be implemented within the structure of motor 120 itself. Controller 140 may be a microcontroller. In examples where vehicle 100 is a vehicle assembly, vehicle 100 may include a global controller and multiple unit controllers, such as controllers for each unit. Thus, vehicle motion management may be enabled at the unit level to receive requests from a manual or virtual driver to coordinate propulsion, braking, and steering.

[0040] Controller 140 may receive control signals from a computer system 160, which includes processing circuitry 170. Computer system 160 may be a vehicle control unit configured to perform various vehicle (unit) control functions, such as vehicle motion management. Computer system 160 may be located locally on vehicle 100 or may be a remote system implemented at a location remote from vehicle 100. Computer system 160 may be communicatively coupled to controller 140 in any suitable manner, such as via circuitry or any other wired, wireless, or network connection known in the art. Furthermore, the communicative coupling may be implemented as a direct connection between controller 140 and computer system 160, or may be implemented as a connection via one or more intermediate entities.

[0041] One function of controller 140 and computer system 160 is to provide control inputs, such as torque, force, or slip requests, to vehicle 100. These control inputs should enable the requested maneuvers of vehicle 100, such as straightening, turning, braking, etc., while ensuring safe and efficient movement of vehicle 100. In many cases, these control inputs are determined to meet a specific objective, such as energy efficiency, safety, range, etc. However, tire wear is not always taken into account.

[0042] As a vehicle operates, the interaction between the tires and the surface they drive on causes them to break down into small particles. This is particularly true during acceleration, braking, and cornering maneuvers. This has several negative effects. One effect is that the broken-down particles are released into the environment, polluting the air, water, and soil. Typical tires are made from a mixture of natural rubber, synthetic rubber, plastic polymers, metals, and other chemical compounds. Particle emissions from these substances can be harmful to the environment. Another effect is that as tire wear increases, the friction provided by the tires decreases. This is because as tires wear, the tread depth of the tires decreases. Therefore, as tire wear increases, the tires are unable to perform to their full capacity. Another effect is that when tire wear exceeds their useful performance, they must be maintained and / or replaced. This further increases the environmental impact of tire wear because more tires must be produced and transported, and vehicles must travel to maintenance locations.

[0043] These negative effects are typically not considered when determining the vehicle motion profile for vehicle 100. The vehicle motion profile includes the instructions and parameters for vehicle 100 to complete a given trip, based on information about the trip, such as the starting location, destination location, total distance, friction profile, curvature, and / or vertical profile of the path to be traveled. The vehicle motion profile may include the speed of vehicle 100, the trajectory of vehicle 100, and the power distribution between the propulsion and braking systems and subsystems of vehicle 100. The motion of vehicle 100 and the use of related components (e.g., motor 120, battery, service brakes 130, etc.) can be planned to meet a certain goal.

[0044] One approach to determining a vehicle's motion profile is predictive energy management, which involves controlling vehicle motion by optimally distributing torque (or power) between different power sources and brakes, taking into account the upcoming road and traffic, to minimize energy consumption over the upcoming road. This can include actions such as regenerative braking, which aims to improve energy efficiency. For example, this can be achieved using a BEV's brake blending strategy, where the entire braking request can be satisfied by different driven axles, increasing the BEV's range and reducing energy consumption. However, certain strategies for improving energy efficiency, such as regenerative braking, involve increasing axial torque on the wheels 110 of the vehicle 100, leading to increased tire wear. In such cases, the benefits of energy efficiency are, at some point, outweighed by the negative effects of tire wear.

[0045] To address this issue, a system and method for determining a vehicle motion profile that considers both energy usage and tire wear is presented. Specifically, a solution is found to an optimization problem that describes the total cost of a vehicle following an upcoming vehicle path, including costs associated with the vehicle's energy usage and costs associated with tire wear. The optimization problem can be an optimal control problem (OCP). The OCP can be a nonlinear optimal control problem (NOCP), although a linear OCP that provides a sufficiently accurate solution can also be formulated.

[0046] A solution is found such that the total cost associated with the solution is below a threshold and satisfies the scope of the path. The solution is a vehicle motion profile that can be implemented to control the vehicle 100 and ensure that the costs of different considerations, including energy use and tire wear, are adequately balanced. According to some examples, the vehicle motion profile includes target tire force trajectories and / or target wheel slip trajectories for at least two wheels to be followed along the upcoming vehicle path. The vehicle motion profile may include a target vehicle unit acceleration and / or a target vehicle speed to be followed along the upcoming vehicle path. Both the target force trajectory and the acceleration profile can be generated under slip constraints, meaning that the vehicle can be controlled to operate according to the target force trajectory and / or acceleration profile without experiencing wheel slip that exceeds a configured slip limit. The vehicle motion profile may include power distribution between the vehicle's drive axles, electric motors, and / or internal combustion engine. The solution minimizes the total cost of energy use and tire wear for the vehicle 100 along the path.

[0047] To this end, a first cost in the optimization problem is associated with energy usage of vehicle 100, while a second cost in the optimization problem is associated with tire wear of vehicle 100. The first cost can be formulated to represent CO2 emissions and / or electrical energy usage. The second cost can be formulated to represent particulate emissions from the tires, reduction in tire tread depth, and / or costs associated with tire maintenance. The first and second costs can be formulated in any suitable manner, such as based on modeling, historical data, or experimentation.

[0048] In some examples, a first cost associated with energy use may be determined based on CO2 emissions. In some examples, this may be expressed as a fuel equivalent cost based on the value of converting the fuel energy into CO2. This value can be a constant , expressing the cost of the fuel in terms of its CO2 content per unit of energy content. For example, for a CO2 content of 2.68 kg / l per litre of fuel and an energy content of 38.6e6 MJ / l, then The value of will be 6.9x10 -8 kg / J. It will be appreciated that the costs associated with CO2 emissions may be determined in any suitable manner.

[0049] In some examples, a first cost associated with energy usage can be determined based on electrical energy usage. In some examples, this can be expressed as the friction braking force and / or dissipative forces in the electric drive train Based on values ​​expressing the cost per unit of electrical energy It will be appreciated that the costs associated with electrical energy usage may be determined in any suitable manner.

[0050] In some examples, a second cost associated with tire wear can be determined based on modeled particulate emissions and / or tire tread depth reduction. It is worth noting that many different factors can affect tire wear, such as axle load, temperature, tire pressure, lateral slip, longitudinal slip, longitudinal slip ratio, slip distance, tire material, tire tread shape, tire size, road type, and vehicle speed. However, many of these factors are uncontrollable during vehicle operation. Therefore, for the purposes of this disclosure, controllable parameters are considered. In particular, the controllable parameters can be axial torque (positive or negative) and / or longitudinal slip associated with one or more wheels 110 of vehicle 100.

[0051] Particle emissions from tires Expressed in kilograms, it can be determined as follows: in is the tire width, is the fitting factor, and is the distance increment (e.g. the distance step of the road where the data is recorded). It may be determined in any suitable manner, for example using equation (1), in the manner described in PCT patent application no. WO 2022 / 106004 in the name of Volvo Truck Corporation, based on a nonlinear tire model, or linearly in accordance with “An Empirical Tire-Wear Model for Heavy-Goods Vehicles” in Tire Science & Technology, 50(3), June 2021.

[0052] Alternatively, the particle emissions from the axle expressed in kilograms It can be determined based on the linear tire model as follows: in is the longitudinal force on the tire, is the number of tires on the axle, and is characterized by: in is the vertical force on the tire.

[0053] Corresponding reduction in tire tread depth It can be determined as follows: in is the tire material density.

[0054] Based on these values, the costs associated with tire wear can be formulated accordingly. For example, the cost of tire wear can be calculated based on the reduction in tire tread depth. The cost of tire wear is calculated based on the tire tread depth at the beginning of the tire life. Based on the tire wear cost and the distance traveled, the axle Tire wear cost rate Furthermore, the tire wear cost term is a convex function of tire torque, longitudinal force, or longitudinal slip, and thus does not impose additional computational burden on existing predictive energy management strategies.

[0055] When determining the technical costs discussed herein, they can be normalized so that they can be compared in a relevant manner. This can be achieved by any suitable means. In one example, the technical costs can be normalized based on monetary units to express them in financial terms. For example, the weighting factors in the costs can be set so that energy efficiency and tire wear have the same units, namely, cost rates (time or distance, Euro / s or Euro / m). In this case, the tire wear cost is a function of vehicle type, axle load, tire type and size, tire price, service and maintenance, and a physics-based validation model that links vehicle usage to tire wear on a specific axle through tire longitudinal slip.

[0056] It will be appreciated that the costs discussed above are merely examples, and that an operator may formulate appropriate costs to describe the effects of axial torque and longitudinal slip in any suitable manner.

[0057] set up is a vehicle path variable (e.g., distance traveled along the path). The NOCP can then be defined to determine one or more of the following as a function of the distance traveled along the path: , the wheel force provided by the kth motor 120 , friction provided by the service brake , ICE integer gear , the integer gear of motor 120 For example, NOCP can be defined as follows: turn up To minimize: Withstand: Fuel equivalence constraint: Vehicle longitudinal dynamics in the spatial domain (road grade positive downhill slope), including the effect of road curvature: Battery State of Charge (SOC) dynamics: Time dynamics: Initial state: motor The consumption uses two quintic fitting functions for positive and negative torques: Dissipative equivalents of electric drive trains: ICE torque limit: Motor torque upper and lower limits : Arrival Time: Battery SOC limit: Battery power limit: Speed ​​Limit: ICE torque or force lower limit: Friction brake lower limit:

[0058] The symbols in the following table apply to the above equations:

[0059] #timg# Front area of ​​the vehicle #timg# Battery resistance #timg# Coefficients of the fitted surface #timg# The total gear ratio of the transmission and differential associated with the ICE #timg# Fitting curve coefficient of maximum ICE torque #timg# Total gear ratio of the transmission and differential related to EM #timg# Fitting curve coefficients of maximum and minimum EM torque #timg# Wheel effective radius #timg# Drag coefficient #timg# Driving distance #timg# Maximum battery energy capacity #timg# Final distance (end of trip) #timg# Equivalent force of vehicle auxiliary equipment #timg# Battery charge status #timg# Friction braking force #timg# Initial distance #timg# Dissipative forces in electric drive trains #timg# time #timg# Engine power #timg# Reference travel time #timg# Fuel Equivalence #timg# Decision variables or input vectors for the optimal control problem #timg# Input equivalent power to the kth EM (the power consumed by the generated EM) #timg# Battery voltage #timg# Wheel force from kth EM #timg# Longitudinal speed #timg# Rolling resistance coefficient #timg# State vector #timg# Wheel longitudinal force of the i-th unit and the j-th axle #timg# The road slope is positive downhill #timg# The lateral force of the wheel of the i-th unit and the j-th axle #timg# ICE gear number #timg# The vertical force of the axle of the i-th unit and the j-th axle #timg# EM gear number #timg# Gravity #timg# ICE transmission efficiency #timg# Fitting function coefficients of positive EM power consumption #timg# Efficiency of EM transmission #timg# Fitting function coefficients of negative EM power consumption #timg# Road friction coefficient #timg# Nonlinear cost function #timg# Air density #timg# Total combined mass #timg# Maximum battery power #timg# Minimum battery power

[0060] Equation (7) is the cost function, where is the number of driven axles. Equations (7) to (27) represent the NOCP, whose input Same with decision variables and states: in is the longitudinal velocity at the tractor's center of gravity, is the charging state, and It is time. This problem can be solved in real time using sequential programming.

[0061] If the vehicle is a BEV and the distance to the destination is less than the calculated nominal range, the mission is not range-critical. Therefore, the nonlinear optimal control problem with predictive cost management (NOCP PCM) with tire wear included in the cost function can be directly used as the preferred controller. Furthermore, if the mission is range-critical, the predictive cost management (PCM) can still be used because it includes constraints on the feasible requested range that satisfies the mission (Equations 20 and 21). For hybrid vehicles, the NOCP PCM is the preferred controller.

[0062] It will be appreciated that these constraints may be formulated mathematically in different ways and have similar technical effects.It will also be appreciated that the NOCP type described above may then be solved by computer-based solution methods known in the art.

[0063] Figure 2 is a flow chart of a computer-implemented method 200 according to an example. The method 200 is used to determine a vehicle motion profile for a vehicle (such as the vehicle 100) to complete a trip. The method 200 can appropriately balance costs associated with tire wear and other factors (including energy usage). The method 200 can be executed by processing circuitry of a computer system (e.g., a computer system that is associated with a vehicle). Figure 1 The processing circuit 150 of the controller 140 described above, or the processing circuit 170 of the computer system 160) is implemented.

[0064] At 202, information related to an upcoming vehicle path is obtained, including the extent of the vehicle path. The vehicle path may represent the entire journey of the vehicle 100 from a starting location to a destination location. The information related to the upcoming vehicle path may include path topography, such as a friction profile, curvature, and / or a vertical profile of the vehicle path.

[0065] At 204, a vehicle motion profile is determined as a solution to an optimization problem that describes the total cost of vehicle 100 following a vehicle path. The optimization problem includes a first cost associated with energy usage by vehicle 100 and a second cost associated with tire wear on vehicle 100. The first cost represents one or more of CO2 emissions and / or electrical energy usage. The second cost represents particulate emissions from the tires, tire tread depth reduction, and / or costs associated with tire maintenance. The range of the vehicle path can be implemented as a constraint in the optimization problem.

[0066] The optimization problem may be an open-loop control program (OCP). The OCP may be a non-linear OCP, although a linear OCP that provides a sufficiently accurate solution can also be formulated. A solution to the optimization problem is found such that the total cost (including the cost associated with energy use and the cost associated with tire wear) is below a threshold, e.g., minimized. Thus, the cost function is the combined cost of energy use and tire wear, and in a non-linear control program (PCM), the optimal decision is found to minimize both energy consumption and tire wear while optimally distributing the requested power between the electric motors of the different axles and the service brakes of the different axles, while maintaining a maximum cruising range.

[0067] The vehicle motion profile includes target tire force trajectories and / or target wheel slip trajectories for at least two wheels to be followed along the upcoming vehicle path. The vehicle motion profile may include a target vehicle unit acceleration and / or a target vehicle speed to be followed along the upcoming vehicle path. Both the target force trajectory and the acceleration profile may be generated under slip constraints, meaning that the vehicle may be controlled to operate according to the target force trajectory and / or acceleration profile without experiencing wheel slip exceeding a configured slip limit. The vehicle motion profile may include power distribution between the vehicle's driven axles, electric motors, and / or internal combustion engine.

[0068] It is important to note that energy efficiency does not mean cost efficiency. There may be situations where an energy efficient power profile increases with the cost of tire wear. In this case, including wear in the cost function helps to reduce the total operating cost. However, reducing cost rather than energy may reduce the range. Therefore, cost optimization can be performed in a predictable manner according to a set requested range, reducing the total cost by including tire wear in the cost function without conflicting the range requirement. Method 200 prioritizes the motors and driven axles not only by energy efficiency but also by total operating cost, especially when there is more than one driven axle in the vehicle. Considering the entire trip means that the requested range is appropriately met, which may not be the case when similar considerations are taken into account in the immediate or short term.

[0069] At 206, the vehicle motion profile may be provided to a control system configured to determine one or more control inputs for the vehicle 100. The control inputs may include a force request, a torque request, and / or a longitudinal slip request for the vehicle 100. In particular, the control inputs may be applied to one or more drive axles of the vehicle 100. Tire wear caused by axial torque and / or longitudinal slip is particularly higher on the drive axles of the vehicle compared to other axles. The reason is that the drive axle tires are under greater pressure during acceleration and deceleration or deceleration than on other axles. For the same reasons, and also due to the fact that the response time of the electric drivetrain is faster than that of a diesel vehicle, tire wear is higher on the drive axles of a battery electric vehicle (BEV).

[0070] Figure 3is a schematic diagram of a computer system 300 for implementing the examples disclosed herein. The computer system 300 is adapted to execute instructions from a computer-readable medium to perform these and / or any of the functions or processes described herein. The computer system 300 can be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. Although only a single device is shown, the computer system 300 may include any collection of devices that individually or jointly execute an instruction set (or multiple instruction sets) to perform any one or more of the methods discussed herein. Therefore, any reference in the present disclosure and / or claims to a computer system, a computing system, a computer device, a computing device, a control system, a control unit, an electronic control unit (ECU), a processor device, a processing circuit, etc. includes a reference to one or more such devices to individually or jointly execute an instruction set (or multiple instruction sets) to perform any one or more of the methods discussed herein. For example, the control system may include a single control unit or multiple control units that are connected to each other or otherwise communicatively coupled so that any executed function can be distributed among the control units as needed. Furthermore, such devices may communicate with each other and other devices through various system architectures, such as directly or via a Controller Area Network (CAN) bus, or the like.

[0071] Computer system 300 may include at least one computing device or electronic device capable of including firmware, hardware, and / or executing software instructions to implement the functionality described herein. Computer system 300 may include processing circuitry 302 (e.g., processing circuitry including one or more processor devices or control units), memory 304, and a system bus 306. Computer system 300 may include at least one computing device having processing circuitry 302. System bus 306 provides an interface for system components including, but not limited to, memory 304 and processing circuitry 302. Processing circuitry 302 may include any number of hardware components for performing data or signal processing or for executing computer code stored in memory 304. Processing circuitry 302 may include, for example, a general-purpose processor, a special-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit containing processing components, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functionality described herein. Processing circuitry 302 may also include computer-executable code that controls the operation of the programmable device.

[0072] The system bus 306 can be any of several types of bus structures, which can be further interconnected to a memory bus (with or without a memory controller), a peripheral bus, and / or a local bus using any of a variety of bus architectures. Memory data 304 can be one or more devices for storing and / or computer code to complete or facilitate the methods described herein. Memory 304 can include database components, object code components, script components, or other types of information structures for supporting various activities herein. Any distributed or local memory device can be utilized with the systems and methods of this specification. Memory 304 can be communicatively connected to processing circuit 302 (e.g., via circuitry or any other wired, wireless, or network connection) and can include computer code for executing one or more processes described herein. Memory 304 may include nonvolatile memory 308 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.) and volatile memory 310 (e.g., random access memory (RAM)), or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a computer or other machine having processing circuitry 302. A basic input / output system (BIOS) 312 may be stored in nonvolatile memory 308 and may include the basic routines that help to transfer information between elements within computer system 300.

[0073] Computer system 300 may further include or be coupled to non-transitory computer-readable storage media such as storage device 314, which may include, for example, an internal or external hard disk drive (HDD) (e.g., Enhanced Integrated Drive Electronics (EIDE) or Serial Advanced Technology Attachment (SATA)), a HDD for storage (e.g., EIDE or SATA), flash memory, etc. Storage device 314 and other drives associated with computer-readable and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, etc.

[0074] The computer code of hard coding or soft coding can be provided in the form of one or more modules. The module can be implemented as software and / or hard coded in the circuit to implement the functionality described herein in whole or in part. These modules can be stored in a storage device 314 and / or volatile memory 310 that may include an operating system 316 and / or one or more program modules 318. All or part of the examples disclosed herein can be implemented as a computer program 320 stored on a temporary or non-temporary computer-usable or computer-readable storage medium (e.g., a single medium or multiple media) such as a storage device 314, the computer program including complex programming instructions (e.g., complex computer-readable program code) that cause the processing circuit 302 to perform the actions described herein. Therefore, the computer-readable program code of the computer program 320 may include software instructions for implementing the functionality of the examples described herein when executed by the processing circuit 302. In some examples, storage device 314 may be a computer program product (e.g., a readable storage medium) having computer program 320 stored thereon, wherein at least a portion of computer program 320 may be loadable (e.g., loaded into a processor) for implementing the functionality of the examples described herein when executed by processing circuitry 302. Processing circuitry 302 may serve as a controller or control system for computer system 300 for implementing the functionality described herein.

[0075] The computer system 300 may include an input device interface 322 configured to receive input and selections to be transmitted to the computer system 300 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices can be connected to the processing circuit 302 through the input device interface 322 coupled to the system bus 306, but can be connected through other interfaces (such as a parallel port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 serial port, a universal serial bus (USB) port, an IR interface, etc.). The computer system 300 may include an output device interface 324 configured to forward output to a display, such as a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 300 may include a communication interface 326 suitable for communicating with a network as appropriate or as needed.

[0076] The operational actions described in any exemplary aspects of this document are described to provide examples and discussion. These actions may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform these actions, or may be performed by a combination of hardware and software. Although a specific order of method actions may be shown or described, the order of the actions may be different. In addition, two or more actions may be performed simultaneously or partially simultaneously.

[0077] According to certain examples, also disclosed are:

[0078] Example 1: A computer system (140, 160, 300) for determining a vehicle motion profile, the computer system (140, 160, 300) comprising processing circuitry (150, 170, 302) configured to: obtain information related to an upcoming vehicle path, including a range of the vehicle path; and determine the vehicle motion profile as a solution to an optimization problem describing a total cost for a vehicle (100) to follow the vehicle path, including a first cost associated with energy usage of the vehicle (100) and a second cost associated with tire wear of the vehicle (100); wherein the total cost associated with the solution to the optimization problem is below a threshold; and the determined vehicle motion profile satisfies the range of the vehicle path.

[0079] Example 2: The computer system (140, 160, 300) of Example 1, wherein the vehicle path represents an entire trip of the vehicle (100) from a starting location to a destination location.

[0080] EXAMPLE 3 The computer system (140, 160, 300) of example 1 or 2, wherein the information related to the upcoming vehicle path includes a friction profile, a curvature, and / or a vertical profile of the vehicle path.

[0081] Example 4: The computer system (140, 160, 300) of any preceding example, wherein the processing circuit (150, 170, 302) is configured to implement the range of the vehicle path as a constraint of the optimization problem.

[0082] Example 5: The computer system (140, 160, 300) of any preceding example, wherein the optimization problem is a nonlinear optimal control problem (NOCP).

[0083] Example 6: The computer system (140, 160, 300) of any preceding example, wherein the first cost represents CO2 emissions and / or electrical energy usage.

[0084] Example 7: The computer system (140, 160, 300) of any preceding example, wherein the second cost represents particle emissions from the tire, friction losses from the tire, and / or costs associated with tire maintenance.

[0085] Example 8: The computer system (140, 160, 300) of Example 7, wherein the processing circuit (150, 170, 302) is configured to determine costs associated with particle emissions and / or friction losses from the tire as a function of longitudinal slip associated with the one or more wheels (100).

[0086] Example 9: A computer system (140, 160, 300) according to any of the preceding examples, wherein the vehicle motion profile includes one or more of the speed of the vehicle (100), the trajectory of the vehicle (100), and the power distribution between the drive axles, electric motors, and / or internal combustion engines of the vehicle (100).

[0087] Example 10: A computer system (140, 160, 300) according to any of the preceding examples, wherein the processing circuit (150, 170, 302) is further configured to provide the vehicle motion profile to a control system (150, 170), the control system being configured to determine one or more control inputs for the vehicle (100).

[0088] Example 11: The computer system (140, 160, 300) of Example 10, wherein the one or more control inputs are associated with one or more drive axles of the vehicle (100).

[0089] Example 12: A vehicle (100) comprising a computer system (140, 160, 300) according to any of the preceding examples.

[0090] Example 13: A computer-implemented method (200) for determining a vehicle motion profile, the method (200) comprising: obtaining (202), by processing circuitry (150, 170, 302) of a computer system (140, 160, 300), information related to an upcoming vehicle path, including a range of the vehicle path; and determining (204), by the processing circuitry (150, 170, 302), the vehicle motion profile as a solution to an optimization problem describing a total cost for a vehicle (100) to follow the vehicle path, including a first cost associated with energy usage of the vehicle (100) and a second cost associated with tire wear of the vehicle (100); wherein the total cost associated with the solution to the optimization problem is below a threshold; and the determined vehicle motion profile satisfies the range of the vehicle path.

[0091] Example 14: The computer-implemented method (200) of Example 13, wherein the vehicle path represents an entire trip of the vehicle (100) from a starting location to a destination location.

[0092] Example 15: The computer-implemented method (200) of Example 13 or 14, wherein the information related to the upcoming vehicle path includes a friction profile, a curvature, and / or a vertical profile of the vehicle path.

[0093] Example 16: The computer-implemented method (200) of any one of Examples 13 to 15, comprising implementing, by the processing circuit (150, 170, 302), the range of the vehicle path as a constraint of the optimization problem.

[0094] Example 17: The computer-implemented method (200) of any one of Examples 13 to 16, wherein the optimization problem is a nonlinear optimal control problem (NOCP).

[0095] Example 18: The computer-implemented method (200) of any one of Examples 13 to 17, wherein the first cost represents CO2 emissions and / or electrical energy usage.

[0096] Example 19: The computer-implemented method (200) of any one of Examples 13 to 18, wherein the second cost represents particle emissions from the tire, friction losses from the tire, and / or costs associated with tire maintenance.

[0097] Example 20: The computer-implemented method (200) of Example 19, comprising determining, by the processing circuit (150, 170, 302), costs associated with particle emissions and / or friction losses from the tire as a function of longitudinal slip associated with the one or more wheels (100).

[0098] Example 21: A computer-implemented method (200) according to any one of Examples 13 to 20, wherein the vehicle motion profile includes one or more of the speed of the vehicle (100), the trajectory of the vehicle (100), and the power distribution between the drive axles, electric machines and / or internal combustion engines of the vehicle (100).

[0099] Example 22: A computer-implemented method (200) according to any one of Examples 13 to 21, further comprising providing, by the processing circuit (150, 170, 302), the vehicle motion profile to a control system (150, 170), the control system being configured to determine one or more control inputs for the vehicle (100).

[0100] Example 23: The computer-implemented method (200) of Example 22, wherein the one or more control inputs are associated with one or more drive axles of the vehicle (100).

[0101] Example 24: A computer program product comprising program code for performing the computer-implemented method (200) according to any one of Examples 13 to 23 when executed by a processing circuit (150, 170, 302).

[0102] Example 25: A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing circuit (150, 170, 302), cause the processing circuit to perform the computer-implemented method (200) of any one of Examples 13 to 23.

[0103] The terms used herein are merely for the purpose of describing particular aspects and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include the plural forms. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms "include" and / or "comprising" when used herein indicate the presence of stated features, integers, actions, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, parts and / or their groups.

[0104] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of this disclosure.

[0105] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another, as shown in the figures. It should be understood that these terms and those discussed above are intended to encompass different device orientations in addition to the orientations depicted in the figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0106] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should also be understood that, unless otherwise explicitly defined herein, the terms used herein should be interpreted as having the same meaning as in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0107] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for purposes of limitation, the scope of the disclosure being set forth in the appended claims.

Claims

1. A computer system (140, 160, 300) for determining a vehicle motion profile, the computer system (140, 160, 300) comprising a processing circuit (150, 170, 302) configured to: obtaining information related to an upcoming vehicle path, including an extent of the vehicle path; and determining a vehicle motion profile as a solution to an optimization problem describing a total cost for a vehicle (100) to follow the vehicle path, including a first cost associated with energy usage of the vehicle (100) and a second cost associated with tire wear of the vehicle (100); wherein the total cost associated with the solution to the optimization problem is below a threshold; and The determined vehicle motion profile satisfies the range of the vehicle path.

2. The computer system (140, 160, 300) of claim 1, wherein the vehicle path represents an entire trip of the vehicle (100) from a starting location to a destination location.

3. The computer system (140, 160, 300) of claim 1 or 2, wherein the information related to the upcoming vehicle path includes a friction profile, a curvature and / or a vertical profile of the vehicle path.

4. The computer system (140, 160, 300) of any preceding claim, wherein the processing circuit (150, 170, 302) is configured to implement the range of the vehicle path as a constraint of the optimization problem.

5. The computer system (140, 160, 300) of any preceding claim, wherein the optimization problem is a nonlinear optimal control problem (NOCP).

6. The computer system (140, 160, 300) of any preceding claim, wherein the first cost represents CO2 emissions and / or electrical energy usage.

7. The computer system (140, 160, 300) of any preceding claim, wherein the second cost represents particle emissions from the tire, friction losses from the tire, and / or costs associated with tire maintenance.

8. The computer system (140, 160, 300) of claim 7, wherein the processing circuit (150, 170, 302) is configured to determine costs associated with particle emissions and / or friction losses from the tire as a function of longitudinal slip associated with the one or more wheels (100).

9. A computer system (140, 160, 300) according to any preceding claim, wherein the vehicle motion profile includes one or more of the speed of the vehicle (100), the trajectory of the vehicle (100), and the power distribution between the drive axles, electric machines and / or internal combustion engines of the vehicle (100).

10. The computer system (140, 160, 300) of any preceding claim, wherein the processing circuit (150, 170, 302) is further configured to provide the vehicle motion profile to a control system (150, 170), the control system configured to determine one or more control inputs for the vehicle (100).

11. The computer system (140, 160, 300) of claim 10, wherein the one or more control inputs are associated with one or more driven axles of the vehicle (100).

12. A vehicle (100) comprising a computer system (140, 160, 300) according to any preceding claim.

13. A computer-implemented method (200) for determining a vehicle motion profile, the method (200) comprising: obtaining (202) information related to an upcoming vehicle path, including an extent of the vehicle path, by processing circuitry (150, 170, 302) of a computer system (140, 160, 300); and determining (204) by the processing circuit (150, 170, 302) a vehicle motion profile as a solution to an optimization problem describing a total cost for a vehicle (100) to follow the vehicle path, including a first cost associated with energy usage of the vehicle (100) and a second cost associated with tire wear of the vehicle (100); wherein the total cost associated with the solution to the optimization problem is below a threshold; and The determined vehicle motion profile satisfies the range of the vehicle path.

14. A computer program product comprising program code for performing the computer-implemented method (200) according to claim 13 when executed by a processing circuit (150, 170, 302).

15. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing circuit (150, 170, 302), cause the processing circuit to perform the computer-implemented method (200) of claim 13.

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