Cruise control algorithm for improved fuel efficiency

Abstract

A cruise control algorithm includes receiving a set speed and a minimum speed; generating a first control signal indicative of a first engine torque request; in response to the first engine torque request, controlling the vehicle to maintain a set speed; detecting the pitching degree of the vehicle; detecting a vehicle speed and generating a second control signal indicative of a first engine torque request in response to the vehicle pitch being greater than zero and the vehicle speed being greater than a minimum speed; in response to the first engine torque request, controlling the vehicle to maintain the first engine torque; in response to the vehicle pitch being greater than zero and the vehicle speed being less than the minimum speed, generating a third control signal indicative of a second engine torque request; and in response to the third engine torque request, controlling the vehicle to maintain the minimum speed.

Description

Technical Field

[0001] The present disclosure relates generally to vehicles and, more particularly, to methods, systems and apparatus for reducing vehicle fuel consumption during cruise control operation, and even more particularly to methods and apparatus for maintaining a vehicle torque request during an uphill climb until a minimum speed is reached or a reduction in road grade is achieved. Background Art

[0002] Cruise control is a system that automatically controls the speed of a car. The system is a servo mechanism that takes over the car's throttle to maintain a steady speed set by the driver. Cruise control is usually activated via user input. Once activated, the driver can set the desired speed by pressing the plus or minus button. The system will maintain this speed even if the road surface is uneven or the car is going uphill or downhill. Cruise control is a good way to reduce driver fatigue on long trips. It can also help improve fuel efficiency because the car will be able to maintain a steady speed without having to accelerate or brake frequently. However, there are situations where cruise control should not be used, such as in stop-and-go traffic, on slippery roads, or in areas where speed limits change frequently. In addition, because cruise control is set to a specific speed, a typical cruise control system may experience poor fuel economy on hilly terrain because the system will use more fuel going uphill and braking downhill to maintain a specific speed.

[0003] Cruise control allows a vehicle to automatically adjust its speed based on a user input to maintain a specific speed. However, for currently available conventional cruise control systems, in the absence of other neighboring vehicles, the ACC controller is programmed to maintain the set cruise control speed regardless of the current road grade or other environmental conditions. For example, when driving uphill, the vehicle experiences an increase in backward force due to gravity, which causes the vehicle to slow down, so the cruise control system will need to apply more throttle to maintain the set speed. In some cases, this increase in throttle may be accompanied by a transmission downshift, resulting in a higher engine speed. Using cruise control on a hill or winding road can cause the system to force multiple transmission shifts, which can cause transmission fluid overheating and premature component wear. This changed engine speed and / or transmission shifting can be annoying to the driver and can cause the vehicle's fuel efficiency to be significantly reduced. Therefore, it is necessary to solve these problems to provide a fuel-efficient cruise control system. In addition, in conjunction with the accompanying drawings and the aforementioned technical field and background technology, other desired features and characteristics of the present disclosure will become apparent from the subsequent detailed description and the appended claims. Summary of the invention

[0004] The present disclosure is for providing driver assistance vehicle control methods and systems and related electrical systems for configuring such systems, methods for manufacturing such systems and methods for operating such systems, as well as motor vehicles and other equipment, such as aircraft, ships, wind turbines and other electric vehicles equipped with onboard propulsion systems. By way of example and not limitation, various embodiments of systems for executing cruise control algorithms, systems for detecting positive vehicle pitch, systems for maintaining previous engine torque, systems for detecting vehicle speed less than a minimum speed, and systems for generating subsequent engine torque in response to vehicle speed less than a minimum speed and vehicle pitch greater than zero degrees are proposed.

[0005] In at least one exemplary embodiment, a method for controlling vehicle speed includes: receiving a set speed and a minimum speed from a user interface; generating a first control signal indicating a first engine torque request; in response to the first engine torque request, controlling the vehicle to maintain the set speed; detecting a vehicle pitch; detecting a vehicle speed; in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than a minimum speed, generating a second control signal indicating the first engine torque request; in response to the first engine torque request, controlling the vehicle to maintain a first engine torque; in response to the vehicle pitch being greater than zero degrees and the vehicle speed being less than the minimum speed, generating a third control signal indicating a second engine torque request; and in response to the third engine torque request, controlling the vehicle to maintain the minimum speed.

[0006] According to another aspect of the present disclosure, the set speed is received from a user interface in response to a user input.

[0007] According to another aspect of the present disclosure, the set speed is determined in response to a vehicle speed during activation of the cruise control system.

[0008] According to another aspect of the present disclosure, vehicle speed is controlled by a vehicle controller in response to a first engine torque request and a second engine torque request.

[0009] According to another aspect of the present disclosure, the minimum speed is received from a user interface in response to a user input.

[0010] According to another aspect of the present disclosure, the minimum speed is a percentage of the set speed and is determined in response to user input received prior to activation of the cruise control algorithm.

[0011] According to another aspect of the present disclosure, wherein the minimum speed is determined in response to a maximum allowable speed reduction, the maximum allowable speed reduction being determined in response to user input received prior to activation of the cruise control algorithm.

[0012] According to another aspect of the present disclosure, the minimum speed is a default value stored in memory during factory initialization of the vehicle.

[0013] According to another aspect of the present disclosure, further comprising deactivating the air conditioner compressor in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than a minimum speed and less than a set speed.

[0014] According to another aspect of the present disclosure, a cruise control system includes a user interface for receiving a set speed and a minimum speed, a pitch sensor for detecting a vehicle pitch, a speed sensor for detecting a vehicle speed, a processor for generating an engine torque request, and a vehicle controller for controlling the vehicle speed in response to the engine torque request.

[0015] According to another aspect of the present disclosure, the set speed is received from a user interface in response to a user input.

[0016] According to another aspect of the present disclosure, the set speed is determined in response to a vehicle speed during activation of the cruise control system.

[0017] According to another aspect of the present disclosure, vehicle speed is controlled by a vehicle controller in response to a first engine torque request and a second engine torque request.

[0018] According to another aspect of the present disclosure, the minimum speed is received from a user interface in response to a user input.

[0019] According to another aspect of the present disclosure, the minimum speed is a percentage of the set speed and is determined in response to user input received prior to activation of the cruise control algorithm.

[0020] According to another aspect of the present disclosure, wherein the minimum speed is determined in response to a maximum allowable speed reduction, the maximum allowable speed reduction being determined in response to user input received prior to activation of the cruise control algorithm.

[0021] According to another aspect of the present disclosure, the minimum speed is a default value stored in memory during factory initialization of the vehicle.

[0022] According to another aspect of the present disclosure, further comprising deactivating the air conditioner compressor in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than a minimum speed and less than a set speed.

[0023] According to another aspect of the present disclosure, a vehicle control system includes: a processor identifying a target vehicle operating in a host vehicle environment and quantifying a set of target vehicle parameters about the target vehicle derived from sensed inputs; a processor modeling state estimates of the host vehicle and the target vehicle by generating a set of speed and torque calculations about each vehicle; a processor generating a set of results from at least one reward function based on one or more modeled state estimates of the host vehicle and the target vehicle; and a processor associating the set of results with driver behavior data, the driver behavior data being adapted by RL to one or more control actions for the driver behavior data.

[0024] According to another aspect of the present disclosure, the minimum speed is received from a user interface in response to a user input, and wherein the minimum speed is at least one of: a user defined speed, a percentage of a set speed, and the set speed minus a maximum speed loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Exemplary embodiments will be described below with reference to the following drawings, wherein like reference numerals denote like elements, and in the drawings:

[0026] Figure 1 is a functional block diagram illustrating an autonomous or semi-autonomous vehicle having a control system that controls vehicle motion in response to a cruise control algorithm and vehicle pitch in a vehicle control system according to an exemplary embodiment;

[0027] Figure 2 shows an exemplary environment for use of an enhanced cruise control system according to various embodiments;

[0028] Figure 3 is a diagram showing the various embodiments according to Figure 1-Figure 2 A schematic diagram of components of a system implemented using a cruise control fuel efficiency algorithm of various embodiments shown; and

[0029] Figure 4 is a diagram showing the various embodiments according to Figure 1-Figure 3 A flow chart of an exemplary method for use of a system implemented using a cruise control fuel efficiency algorithm is shown for various embodiments. DETAILED DESCRIPTION

[0030] The following detailed description is merely exemplary in nature and is not intended to limit application and use. In addition, it is not intended to be bound by any express or implied theory presented in the aforementioned technical field, background technology, summary of the invention or the following detailed description. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic and / or processor device alone or in any combination, including but not limited to: application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), electronic circuits, processors (shared, dedicated or groups) and memories that execute one or more software or firmware programs, combinational logic circuits and / or other suitable components that provide the described functions.

[0031] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by any number of hardware, software, and / or firmware components configured to perform specified functions. For example, embodiments of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any number of systems, and the systems described herein are merely exemplary embodiments of the present disclosure.

[0032] For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, machine learning, image analysis, and other functional aspects of the system (and the various operating components of the system) may not be described in detail herein. In addition, the connecting lines shown in the various figures included herein are intended to represent example functional relationships and / or physical connections between various elements. It should be noted that there may be many alternative or additional functional relationships or physical connections in the embodiments of the present disclosure.

[0033] refer to Figure 1 According to various embodiments, the control system 100 is associated with a vehicle 10 (also referred to herein as a "host vehicle"). Generally, the control system (or simply "system") 100 provides control of various actions of the vehicle 10 (e.g., torque control) established by reinforcement learning (RL), which is stored or can be stored in a DNN-type model that controls operations in response to data from vehicle inputs, such as the following in combination Figure 2-Figure 4 Described in more detail.

[0034] In various exemplary embodiments, the system 100 provides a process using an algorithm that controls torque and speed in the embedded controller software of the host vehicle 10 of the system 100, thereby allowing DNN to be used for ACC behavior prediction models. The system 100 enables learning of driver preferences for following distances of different target vehicles (such as one target vehicle) and classifies the driver's preferences based on driving scenarios, such as traffic signs, stop-and-go traffic, city driving, etc. The system 100 using the Q matrix can build a knowledge base of target vehicles that follow performance preferences by utilizing online and historical driver and environment information.

[0035] like Figure 1 As shown, the vehicle 10 generally includes a chassis 12, a body 14, front wheels 16, and rear wheels 18. The body 14 is disposed on the chassis 12 and substantially surrounds the components of the vehicle 10. The body 14 and the chassis 12 may together form a frame. The wheels 16-18 are each rotatably coupled to the chassis 12 near a respective corner of the body 14. In various embodiments, the wheels 16, 18 comprise a wheel assembly that also includes tires that are respectively associated.

[0036] In various embodiments, the vehicle 10 is autonomous or semi-autonomous, and the control system 100 and / or its components are incorporated into the vehicle 10. The vehicle 10 is, for example, a vehicle that is automatically controlled to transport passengers from one location to another. The vehicle 10 is depicted as a passenger car in the illustrated embodiment, but it should be understood that any other means of transportation may also be used, including motorcycles, trucks, sport utility vehicles (SUVs), recreational vehicles (RVs), marine vessels, airplanes, etc.

[0037] As shown, the vehicle 10 generally includes a propulsion system 20, a transmission system 22, a steering system 24, a braking system 26, a canister purge system 31, one or more user input devices 27, a sensor system 28, an actuator system 30, at least one data storage device 32, at least one controller 34, and a communication system 36. In various embodiments, the propulsion system 20 may include an internal combustion engine, an electric machine such as a traction motor, and / or a fuel cell propulsion system. The transmission system 22 is configured to transmit power from the propulsion system 20 to the wheels 16 and 18 according to a selectable speed ratio. According to various embodiments, the transmission system 22 may include a step-ratio automatic transmission, a continuously-variable transmission, or other suitable transmission.

[0038] Braking system 26 is configured to provide braking torque to wheels 16 and 18. In various embodiments, braking system 26 may include friction brakes, brake-by-wire brakes, a regenerative braking system such as an electric motor, and / or other suitable braking systems.

[0039] Steering system 24 affects the position of wheels 16 and / or wheels 18. Although depicted as including a steering wheel for illustrative purposes, in some embodiments contemplated within the scope of the present disclosure, steering system 24 may not include a steering wheel.

[0040] The controller 34 includes at least one processor 44 (and neural network 33) and a computer-readable storage device or medium 46. As described above, in various embodiments, the controller 34 (e.g., its processor 44) provides data about the expected future path of the vehicle 10 to the steering control system 84 in advance, including expected future steering instructions for controlling steering for a limited period of time in the event that communication with the steering control system 84 becomes unavailable. In addition, in various embodiments, the controller 34 provides the steering control system 84 with data about the expected future path of the vehicle 10 via the communication system 36 described further below, such as via a communication bus and / or a transmitter ( Figure 1 ), providing communication to the steering control system 84.

[0041] In various embodiments, the controller 34 includes at least one processor 44 and a computer readable storage device or medium 46. The processor 44 can be any custom or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), a secondary processor in a number of processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), any combination thereof, or any device generally used to execute instructions. For example, the computer readable storage device or medium 46 can include volatile and non-volatile storage in read-only memory (ROM), random access memory (RAM), and key memory (KAM). KAM is a persistent or non-volatile memory that can be used to store multiple neural networks and various operating variables when the processor 44 loses power. The computer readable storage device or medium 46 can be implemented using any of a number of known memory devices, such as PROM (programmable read-only memory), EPROM (electrical PROM), EEPROM (electrically erasable PROM), flash memory, or any other electrical memory device, magnetic memory device, optical memory device, or combination memory device capable of storing data, some of which represents executable instructions used by the controller 34 to control the vehicle 10.

[0042] The instructions may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing logical functions. The instructions, when executed by the processor 44, receive and process signals from the sensor system 28, perform logic, calculations, methods and / or algorithms for automatically controlling components of the vehicle 10, and generate control signals that are sent to the actuator system 30 to automatically control components of the vehicle 10 based on the logic, calculations, methods and / or algorithms. Although Figure 1Only one controller 34 is shown, but embodiments of the vehicle 10 may include any number of controllers 34 that communicate via any suitable communication medium or combination of communication media and collaborate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals for automatically controlling features of the vehicle 10.

[0043] like Figure 1 As depicted, in addition to the above-described steering system 24 and controller 34, the vehicle 10 generally includes a chassis 12, a body 14, front wheels 16, and rear wheels 18. The body 14 is disposed on the chassis 12 and substantially surrounds the components of the vehicle 10. The body 14 and the chassis 12 may together form a frame. The wheels 16-18 are each rotatably coupled to the chassis 12 near a respective corner of the body 14. In various embodiments, the wheels 16, 18 comprise a wheel assembly that also includes a respectively associated tire.

[0044] In various embodiments, the vehicle 10 is an autonomous vehicle, and the control system 100 and / or its components are incorporated into the vehicle 10. The vehicle 10 is, for example, a vehicle that is automatically controlled to transport passengers from one location to another. The vehicle 10 is depicted as a passenger car in the illustrated embodiment, but it should be understood that any other means of transportation may also be used, including motorcycles, trucks, sport utility vehicles (SUVs), recreational vehicles (RVs), marine vessels, airplanes, etc.

[0045] As shown, the vehicle 10 also generally includes a propulsion system 20, a transmission system 22, a braking system 26, one or more user input devices 27, a sensor system 28, an actuator system 30, at least one data storage device 32, and a communication system 36. In various embodiments, the propulsion system 20 may include an internal combustion engine, an electric machine such as a traction motor, and / or a fuel cell propulsion system. The transmission system 22 is configured to transmit power from the propulsion system 20 to the wheels 16 and 18 according to a selectable speed ratio. According to various embodiments, the transmission system 22 may include a stepped automatic transmission, a continuously variable transmission, or other suitable transmission.

[0046] Braking system 26 is configured to provide braking torque to wheels 16 and 18. In various embodiments, braking system 26 may include friction brakes, brake-by-wire brakes, a regenerative braking system such as an electric motor, and / or other suitable braking systems.

[0047] Steering system 24 affects the position of wheels 16 and / or wheels 18. Although depicted as including a steering wheel for illustrative purposes, in some embodiments contemplated within the scope of the present disclosure, steering system 24 may not include a steering wheel.

[0048] Controller 34 includes a vehicle controller that will be directly affected based on the output of the neural network 33 model. In an exemplary embodiment, a feed-forward operation can be applied to the adjustment factor that is a continuous output of the neural network 33 model to generate a control action for the desired torque or other similar action (e.g., in the case of a continuous neural network 33 model, the continuous APC / SPARK prediction value is the output).

[0049] In various embodiments, the one or more user input devices 27 receive input from one or more passengers of the vehicle 10 (and the driver 11). In various embodiments, the input includes a desired travel destination for the vehicle 10. In some embodiments, the one or more input devices 27 include an interactive touch screen in the vehicle 10. In some embodiments, the one or more input devices 27 include a speaker for receiving audio information from the passenger. In some other embodiments, the one or more input devices 27 may include one or more other types of devices and / or user devices (e.g., smartphones and / or other electronic devices) that can be coupled to the passenger.

[0050] The sensor system 28 includes one or more sensors 40a-40n that sense observable conditions of the external environment and / or the internal environment of the vehicle 10. The sensors 40a-40n include, but are not limited to, radar, lidar, global positioning system, optical camera, thermal imaging camera, ultrasonic sensor, inertial measurement unit, and / or other sensors.

[0051] The actuator system 30 includes one or more actuators 42a-42n that control one or more vehicle features such as, but not limited to, the canister purge system 31, the intake system 38, the propulsion system 20, the transmission system 22, the steering system 24, and the braking system 26. In various embodiments, the vehicle 10 may also include Figure 1 Interior and / or exterior vehicle features not shown may include various doors, trunk, and cabin features such as air, music, lighting, touch screen display components (such as those used in conjunction with a navigation system), etc.

[0052] The data storage device 32 stores data for automatically controlling the vehicle 10, including data of a DNN established by RL for predicting driver behavior for vehicle control. In various embodiments, the data storage device 32 stores machine learning models of DNNs and other data models established by RL. The model established by RL can be used as a DNN behavior prediction model or a model established by RL. In an exemplary embodiment, the DNN does not require separate training, but a set of learning functions is used to implement the DNN behavior prediction model (i.e., DNN prediction model). In various embodiments, the neural network 33 (i.e., DNN behavior prediction model) can be established by RL, or trained by a remote system through a supervised learning method, and transmitted or provided in the vehicle 10 (wirelessly and / or by wire), and stored in the data storage device 32. The DNN behavior prediction model can also be trained via supervised or unsupervised learning based on input vehicle data of the main vehicle operation and / or sensory data about the main vehicle operating environment.

[0053] The data storage device 32 is not limited to control data, as other data may also be stored in the data storage device 32. For example, route information may also be stored in the data storage device 32, i.e., a set of road segments (geographically associated with one or more defined maps) that together define a route that a user may take from a starting location (e.g., the user's current location) to a target location. As will be appreciated, the data storage device 32 may be part of the controller 34, separate from the controller 34, or part of the controller 34 and part of a separate system.

[0054] The controller 34 implements the logic model established by RL or for the DNN based on the DNN behavior model that has been trained with a set of values, and the controller 34 includes at least one processor 44 and a computer-readable storage device or medium 46. The processor 44 can be any customized or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor in several processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), any combination thereof, or any device generally used to execute instructions. For example, the computer-readable storage device or medium 46 may include volatile and non-volatile storage in a read-only memory (ROM), a random access memory (RAM), and a never-fail memory (KAM). KAM is a persistent or non-volatile memory that can be used to store various operating variables when the processor 44 loses power. The computer readable storage device or medium 46 may be implemented using any of a number of known memory devices, such as a PROM (programmable read-only memory), an EPROM (electrical PROM), an EEPROM (electrically erasable PROM), flash memory, or any other electrical, magnetic, optical, or combination memory device capable of storing data, some of which represents executable instructions used by the controller 34 to control the vehicle 10.

[0055] The instructions may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing logical functions. The instructions, when executed by the processor 44, receive and process signals from the sensor system 28, execute logic, calculations, methods and / or algorithms for automatically controlling components of the vehicle 10, and generate control signals that are sent to the actuator system 30 to automatically control components of the vehicle 10 based on the logic, calculations, methods and / or algorithms. Although Figure 1 Only one controller 34 is shown, but embodiments of the vehicle 10 may include any number of controllers 34 that communicate via any suitable communication medium or combination of communication media and cooperate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals to automatically control features of the vehicle 10.

[0056] The communication system 36 is configured to wirelessly transmit information to and from other entities 48, such as, but not limited to, other vehicles ("V2V" communications), infrastructure ("V2I" communications), telematic systems, and / or user devices (regarding Figure 2In an exemplary embodiment, the communication system 36 is a wireless communication system that is configured to communicate via a wireless local area network (WLAN) using the IEEE 802.11 standard or by using cellular data communications. However, additional or alternative communication methods, such as dedicated short-range communication (DSRC) channels, are also considered within the scope of the present disclosure. A DSRC channel refers to a one-way or two-way short-range to medium-range wireless communication channel designed specifically for automotive use and a set of corresponding protocols and standards.

[0057] In various embodiments, the communication system 36 is used for communication between the controllers 34, including data related to the expected future path of the vehicle 10, including expected future steering instructions. In addition, in various embodiments, the communication system 36 can facilitate communication between the steering control system 84 and / or more other systems and / or devices.

[0058] In certain embodiments, the communication system 36 is also configured for communication between the sensor system 28, the input device 27, the actuator system 30, one or more controllers (e.g., the controller 34), and / or a plurality of other systems and / or devices. For example, the communication system 36 may include any combination of a controller area network (CAN) bus and / or direct wiring between the sensor system 28, the actuator system 30, the one or more controllers 34, and / or one or more other systems and / or devices. In various embodiments, the communication system 36 may include one or more transceivers for communicating with one or more devices and / or systems of the vehicle 10, devices of passengers (e.g., Figure 2 Communicates with user equipment 54) and / or one or more remote information sources (e.g., GPS data, traffic information, weather information, etc.).

[0059] Now go to Figure 2 , shows an exemplary environment 200 for using an enhanced cruise control system according to various embodiments. The exemplary environment 200 shows a vehicle 210 equipped with cruise control and a slope of of road surface 220. In some exemplary embodiments, vehicle 210 may have transitioned from a flat grade while executing a cruise control algorithm at a set speed defined by the driver. In order to maintain the set speed, the cruise control controller will generate a corresponding engine torque request to couple to a throttle body controller or an engine control unit (ECU) to maintain the set speed. When vehicle 210 transitions uphill, the cruise control controller traditionally must increase the engine torque request to maintain the set speed. Likewise, when the vehicle reaches the top of a hill, the cruise control controller will need to apply reduced engine torque and / or apply brakes to arrest the vehicle momentum downhill to maintain the set speed, further reducing fuel economy.

[0060] Cruise control is an electronic system that allows drivers to set a specific speed for their car and then take their foot off the accelerator pedal. The system uses a servo mechanism to take over the throttle and maintain a steady speed. Cruise control can be activated by controls on the steering wheel or user interface. Cruise control is useful for driving at a constant speed, especially on highways and fast roads with few curves or grade changes. Cruise control can reduce driver fatigue and stress, and can also prevent speeding and improve fuel efficiency. However, cruise control may not operate safely and effectively at night or in bad weather. Also, cruise control may result in lower fuel economy when used on roads with frequent grade changes, such as in hilly areas.

[0061] The engine torque command is a signal sent from the driver's throttle to the ECU. It tells the ECU how much torque the driver wants the engine to produce. The ECU then uses this signal to control fuel injection and ignition timing to achieve the desired torque output. The engine torque command is usually measured in Newton meters (Nm). For example, a torque command of 100Nm means that the driver wants the engine to produce 100Nm of torque. The engine torque command is a key factor in determining the performance of the engine. If the torque command is too low, the engine will not be able to produce enough power. If the torque command is too high, the engine may overheat or even damage itself. The engine torque command is also used to control the transmission. The transmission uses the torque command to determine how many gears to shift to. For example, if the driver wants to accelerate quickly, the ECU will send a high torque command to the transmission, which will cause the transmission to shift to a lower gear. The engine torque command is a complex signal that is affected by several factors, including the driver's throttle position, engine speed, and engine load. The ECU uses various sensors to measure these factors and then adjusts the torque command accordingly. Factors that affect the engine torque command include the driver's throttle position, engine speed, engine load, and engine temperature. The engine torque command is a key signal used to control engine performance.

[0062] The cruise control system is set to maintain a constant speed set by the user. This may cause the cruise control controller to increase the engine torque request to maintain that speed when going uphill and to brake when going downhill. In order to improve fuel economy going uphill, it is advantageous to allow the cruise control system to deviate from the cruise control set speed and hold the torque request constant up to a certain user-defined speed limit. The system may first detect the grade of the road in response to the current vehicle pitch to determine whether the vehicle is going uphill, flat, or downhill. Reducing the speed when going uphill will enable the cruise control system to reduce the vehicle speed to the set speed when going uphill, thereby potentially avoiding braking when going downhill. In defining a new setting for the minimum speed, a new user input and an accompanying set of user controls may be added. The cruise control algorithm may also include an updated torque control strategy used during cruise control operation.

[0063] In some exemplary embodiments, the cruise control algorithm will receive a user-defined low speed input indicating the minimum speed that the user will allow the vehicle to reach before requesting an increase in torque. For example, the user may define the minimum speed as 15 miles per hour below the set cruise control speed. Alternatively, the user may define the minimum speed as a percentage of the set cruise control speed, such as 85% of the set cruise control speed. The cruise control algorithm is then configured to monitor the vehicle pitch via a vehicle pitch sensor, etc. If the pitch sensor is positive, the algorithm will determine that the torque request remains unchanged until the user-entered minimum speed is reached. If the pitch sensor is positive and the minimum speed is reached, the minimum speed can be maintained until the pitch sensor reports a horizontal value. If the pitch sensor is horizontal, normal cruise control operation can be resumed based on the expected acceleration. The reduced torque request during climbing promotes an increase in mileage due to lower gasoline / electricity consumption.

[0064] Now Figure 3 , showing the various embodiments according to Figure 1-Figure 2 A schematic diagram of components of a system 300 is shown in which various embodiments are implemented using a cruise control fuel efficiency algorithm. The exemplary system 300 may include a user input 310, a processor 330, a vehicle controller 350, a pitch sensor 340, and a memory 260.

[0065] An exemplary user input 310 may be a touch pad mounted on a steering wheel, a center console touch pad, or other user interface for receiving user input 310 indicating cruise control activation, set speed, and minimum speed. Typically, the driver may activate the cruise control system and algorithm by starting the cruise control system while driving at a desired set speed. The cruise control system will then use the current speed of the vehicle at the time of activation as the set speed. Alternatively, the driver may press a resume button, etc., and the cruise control system will use a previously stored set speed as the current set speed. This may mean that the controller 330 may generate an engine torque request so that the vehicle increases or decreases speed to transition from the current speed to the requested set speed.

[0066] The driver can use user input 310 to enter the minimum speed. The minimum speed is the lowest speed reached when climbing a hill with a constant engine torque request. For example, the driver can enter a precise speed (such as fifty-five miles per hour), a maximum speed reduction (such as ten miles per hour), or a maximum speed reduction percentage (such as fifteen percent). The minimum speed can be entered by the driver during the cruise control configuration before the vehicle moves. Alternatively, the driver can start the cruise control algorithm, for example, activate the algorithm when driving at a set speed, and then receive a prompt to select the minimum speed from user input 310. The driver can then select the minimum speed by pressing the arrow keys on the steering wheel, can turn the job wheel, press the level, etc., until the minimum speed is indicated. The driver can then confirm the minimum speed by a separate key, etc. The minimum speed can then be stored in the memory 360 for use by the cruise control fuel efficiency algorithm. In some exemplary embodiments, the cruise control fuel efficiency algorithm can be executed as part of the fuel economy mode of the vehicle and automatically uses the user-defined minimum speed or the default minimum speed stored in the memory 360.

[0067] The processor 330 may be a component of a cruise control controller, an ECU, a vehicle control system, etc. The processor 330 is configured to execute a cruise control fuel efficiency algorithm in response to the driver activating the cruise control system via the user input 310 and the set speed. The processor 330 may retrieve the minimum speed from the memory 360. The processor 330 is configured to generate an engine torque request or similar control signal to couple to the vehicle controller 350. The vehicle controller 350 controls the vehicle throttle body controller, etc., so that the vehicle maintains the set speed. In some exemplary embodiments, the vehicle controller 350 may then send the current vehicle speed back to the processor 330 for use by the cruise control algorithm. The processor 330 then operates to receive a vehicle pitch value from the pitch sensor 340. If the vehicle pitch value indicates that the vehicle is climbing a hill, the processor 330 may continue to couple the previous engine torque request to the vehicle controller 350. The processor 350 then receives the current vehicle speed from the vehicle controller 350 and compares the current vehicle speed with the minimum speed. If the current vehicle speed is less than the minimum speed, the processor 330 may then couple an updated engine torque request to the vehicle controller 350 so that the vehicle maintains the minimum speed. Alternatively, if the current vehicle speed is less than the minimum speed, the processor 330 may couple an updated engine torque request so that the set speed is restored and the vehicle accelerates from the minimum speed to the set speed when climbing a hill.

[0068] In some exemplary embodiments, in response to the vehicle pitch value indicating that the vehicle is climbing a hill, the processor 330 may continue to couple the previous engine torque request to the vehicle controller 350, and the processor 330 may also be configured to disconnect one or more heating and air conditioning components, such as an air conditioning compressor. Disconnecting the air conditioning compressor may advantageously reduce the engine torque required to maintain a set speed, or may result in a rate of vehicle speed loss when the vehicle is climbing a hill at the previous engine torque request. Disconnecting one or more heating and air conditioning components in response to the pitch value indicating that the vehicle is climbing a hill may result in an engine torque provided to the driveline that is greater than the torque applied during a level grade using the one or more heating and air conditioning components.

[0069] Pitch sensor 340 is configured to detect the current vehicle pitch and send data indicating the current vehicle pitch to processor 330 and / or vehicle controller 350. Pitch sensor 340 may be part of a system such as a six-axis inertial navigation system or inertial measurement unit (IMU), which detects position, orientation, and velocity information with the aid of accelerometers and gyroscope sensors, which may be used by the gyroscope sensor to make predictions about the next position, orientation, and velocity using various algorithms.

[0070] Figure 4 An exemplary flow chart is shown, which illustrates the Figure 1-Figure 3 Various embodiments are shown in a method 400 for use of a system implemented using a cruise control fuel efficiency algorithm. In some exemplary embodiments, the exemplary method is first operable to receive 405 a user input indicating a minimum speed. The minimum speed may be a percentage of a cruise control set speed or a reduction in maximum speed, such as fifteen miles per hour. A user, such as a vehicle driver, may enter or select the minimum speed using a user interface, such as an infotainment display, a dashboard display, or other user input.

[0071] The method may then be operable to activate 410 a cruise control algorithm. The cruise control algorithm may be activated in response to a second user input on a user interface, such as a button on a steering wheel. The cruise control algorithm then receives 412 a set speed. In some exemplary embodiments, the set speed of the cruise control algorithm may be the current speed of the vehicle when the cruise control system is activated. Alternatively or additionally, the user may input the set speed or increase or decrease the set speed using the user interface.

[0072] In response to activation of the cruise control system and receiving a set speed, the method may then be operable to generate 414 an engine torque request corresponding to the set speed. The engine torque request indicates the engine torque required to cause the vehicle to travel at the set speed. The method then detects 415 the vehicle pitch. If the vehicle pitch is zero degrees or less, an engine torque request is generated 417 so that the vehicle maintains the set speed.

[0073] If the vehicle pitch is greater than zero degrees 420, indicating that the vehicle is traveling uphill or on a slope, the method then maintains the previous engine torque request. In response to sending the previous engine torque request, the method next receives 435 the current vehicle speed. The current vehicle speed may be received from a vehicle controller or other vehicle sensor or controller. The method next compares 440 the current vehicle speed to a minimum speed. If the current vehicle speed is not less than the minimum speed, the vehicle returns to detecting 415 the vehicle pitch.

[0074] If the current vehicle speed is less than the minimum speed, the method may then operate to increase 450 the engine torque request and send the increased engine torque request to the vehicle controller. In some exemplary embodiments, the increased engine torque request may cause the vehicle controller to maintain the minimum speed while the vehicle is climbing a hill and the pitch remains greater than zero. Alternatively, the increased engine torque request may indicate the engine torque required to restore the set speed. After the increased torque request is sent to the vehicle controller, the method returns to detecting 415 the vehicle pitch.

[0075] It should be understood that Figure 1-Figure 4 The process may include any number of additional or alternative tasks, Figure 1-Figure 4 The tasks shown in the figure do not need to be performed in the order shown, and Figure 1-Figure 3 The processes may be incorporated into more comprehensive programs or processes having additional functionality not described in detail herein. Furthermore, as long as the intended overall functionality remains the same, Figure 1-Figure 3 One or more of the tasks shown may be Figure 1-Figure 4 The process is omitted in the embodiment shown.

[0076] The foregoing detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and use of these embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as exemplary is not necessarily to be construed as preferred or more advantageous than other implementations. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing technical field, background, or detailed description.

[0077] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that there are numerous variations. It should also be understood that the exemplary embodiment or multiple exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Instead, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiment or multiple exemplary embodiments.

[0078] It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof

Claims

1. A method for controlling vehicle speed, comprising: receiving a set speed and a minimum speed from a user interface; generating a first control signal indicative of a first engine torque request; In response to the first engine torque request, controlling a vehicle to maintain the set speed; Detect vehicle pitch; detecting the vehicle speed; generating a second control signal indicative of the first engine torque request in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than the minimum speed; In response to the first engine torque request, controlling the vehicle to maintain a first engine torque; generating a third control signal indicative of a second engine torque request in response to the vehicle pitch being greater than zero degrees and the vehicle speed being less than the minimum speed; as well as In response to the second engine torque request, the vehicle is controlled to maintain the minimum speed.

2. The method according to claim 1, wherein: The set speed is received from the user interface in response to user input.

3. The method according to claim 1, wherein: The set speed is determined in response to the vehicle speed during activation of the cruise control system.

4. The method according to claim 1, wherein: The vehicle speed is controlled by a vehicle controller in response to the first engine torque request and the second engine torque request.

5. The method according to claim 1, wherein: The minimum speed is received from the user interface in response to user input.

6. The method according to claim 1, wherein: The minimum speed is a percentage of the set speed and is determined in response to user input received prior to activating the cruise control algorithm.

7. The method according to claim 1, wherein: The minimum speed is determined in response to a maximum allowable speed reduction determined in response to user input received prior to activating the cruise control algorithm.

8. The method according to claim 1, wherein: The minimum speed is a default value stored in memory during vehicle factory initialization. 9 . The method of claim 1 , further comprising deactivating an air conditioner compressor in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than the minimum speed and less than the set speed.

10. A cruise control system comprising: A user interface for receiving a set speed and a minimum speed; A pitch sensor, used to detect the pitch of the vehicle; Speed ​​sensor, used to detect vehicle speed; a processor for generating a first control signal indicative of a first engine torque request in response to the set speed, generating a second control signal indicative of the first engine torque request in response to the vehicle pitch being greater than zero degrees and the vehicle speed being greater than the minimum speed, and generating a third control signal indicative of a second engine torque request in response to the vehicle pitch being greater than zero degrees and the vehicle speed being less than the minimum speed; as well as A vehicle controller is configured to control the vehicle speed in response to the first engine torque request and the second engine torque request.

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