Closed-loop control of regenerative braking

Abstract

A system, method, and vehicle for closed-loop control of regenerative braking. In one embodiment, the system includes a regenerative braking subsystem and a vehicle controller. The vehicle controller is configured to command the regenerative braking subsystem to apply a first amount of regenerative braking torque. The vehicle controller is further configured to determine a current vehicle deceleration when applying the first amount of regenerative braking torque. The vehicle controller is further configured to determine a difference between the current vehicle deceleration and a target vehicle deceleration. The vehicle controller is further configured to set a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration. The vehicle controller is further configured to command the regenerative braking subsystem to apply the second amount of regenerative braking torque.

Description

Technical Field

[0001] The present disclosure relates generally to regenerative braking in vehicles and more particularly to closed-loop control of regenerative braking in vehicles. Background Art

[0002] Friction braking systems in vehicles waste significant amounts of energy. For example, with hydraulic braking systems, all of the vehicle's kinetic energy is irreversibly lost to heat generated by friction. Regenerative braking systems allow for the recapture of some of the vehicle's kinetic energy by converting it into electrical energy that is used to power the vehicle. Summary of the Invention

[0003] Conventional regenerative braking systems apply regenerative braking in an open-loop manner. For example, some conventional regenerative braking systems apply a fixed amount of regenerative braking based on accelerator pedal position. Variables that affect vehicle deceleration behavior, such as vehicle mass, are difficult to quickly and accurately determine. Consequently, conventional regenerative braking systems often do not account for these variables in their open-loop control schemes. By not accounting for vehicle mass and other variables that affect vehicle deceleration behavior, conventional open-loop regenerative braking systems provide inconsistent regenerative braking performance, which can cause discomfort to vehicle occupants. Furthermore, conventional open-loop regenerative braking systems do not take advantage of the opportunity to recapture additional kinetic energy when the vehicle is fully loaded with cargo or people.

[0004] Therefore, the present disclosure provides a system for closed-loop control of regenerative braking in a vehicle. In one embodiment, the system includes a regenerative braking subsystem and a vehicle controller. The vehicle controller is configured to command the regenerative braking subsystem to apply a first amount of regenerative braking torque. The vehicle controller is further configured to determine a current vehicle deceleration when applying the first amount of regenerative braking torque. The vehicle controller is further configured to determine a difference between the current vehicle deceleration and a target vehicle deceleration. The vehicle controller is further configured to set a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration. The vehicle controller is further configured to command the regenerative braking subsystem to apply the second amount of regenerative braking torque.

[0005] The present disclosure also provides a method for closed-loop control of regenerative braking in a vehicle. The method includes applying a first amount of regenerative braking torque using a regenerative braking subsystem of the vehicle. The method also includes determining a current vehicle deceleration while applying the first amount of regenerative braking torque. The method also includes determining a difference between the current vehicle deceleration and a target vehicle deceleration. The method also includes setting a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration. The method also includes applying the second amount of regenerative braking torque using the regenerative braking subsystem.

[0006] The present disclosure also provides a vehicle, which, in one embodiment, includes a regenerative braking subsystem and a vehicle controller. The vehicle controller is configured to command the regenerative braking subsystem to apply a first amount of regenerative braking torque. The vehicle controller is further configured to determine a current vehicle deceleration when applying the first amount of regenerative braking torque. The vehicle controller is further configured to determine a difference between the current vehicle deceleration and a target vehicle deceleration. The vehicle controller is further configured to set a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration. The vehicle controller is further configured to command the regenerative braking subsystem to apply the second amount of regenerative braking torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, in which like reference numerals refer to like or functionally similar elements throughout the various views, together with the following detailed description, are incorporated into and constitute a part of the specification and serve to further illustrate the embodiments and to explain various principles and advantages of these embodiments.

[0008] Figure 1 is a block diagram of one example of a vehicle equipped with a system for closed-loop control of regenerative braking, according to some embodiments.

[0009] Figure 2 According to some embodiments Figure 1 A block diagram of an example of a vehicle controller for the system.

[0010] Figure 3 is a flow chart of one example of a method for closed-loop control of regenerative braking in a vehicle, according to some embodiments.

[0011] Components of the systems and methods are represented by conventional symbols in the drawings where appropriate, with only specific details relevant to an understanding of the embodiments being shown so as not to obscure the disclosure with details that would be apparent to one of ordinary skill in the art having the benefit of this description. DETAILED DESCRIPTION

[0012] Figure 1 is a block diagram of one example of a vehicle 100 equipped with a system 102 for closed-loop control of regenerative braking. Figure 1 The vehicle 100 shown includes a left front wheel 104, a right front wheel 106, a left rear wheel 108, and a right rear wheel 110. In some embodiments, the vehicle 100 is an electric vehicle. In other embodiments, the vehicle 100 is a hybrid vehicle that also includes a gasoline engine (not shown). Figure 1 The illustrated system 102 includes a regenerative braking subsystem 112 , sensors 114 , other vehicle systems 116 , a vehicle controller 118 (eg, a vehicle control unit), an accelerator pedal 120 , and a brake pedal 122 .

[0013] The components of system 102, along with various other modules and components, are electrically coupled to one another by or through one or more control or data buses (e.g., bus 124), enabling communication therebetween. The use of control and data buses for interconnecting and communicating between various modules and components is well known to those skilled in the art in light of the invention described herein. In some embodiments, bus 124 is a Controller Area Network (CAN™) bus. In some embodiments, bus 124 is an Automotive Ethernet™, FlexRay™ communication bus, or other suitable wired bus. In alternative embodiments, some or all components of system 102 may be communicatively coupled using a suitable wireless modality (e.g., Bluetooth™ or near-field communication). In some embodiments, accelerator pedal 120 and / or brake pedal 122 communicate with other components of system 102 by transmitting analog voltage signals indicating, for example, pedal position.

[0014] For ease of description, Figure 1 The illustrated system 102 includes each of the aforementioned components. Alternative embodiments may include one or more of each component, or may exclude or combine some components. A vehicle controller 118 (described in more detail below) operates the regenerative braking subsystem 112, sensors 114, and other vehicle systems 116 to provide regenerative braking according to the methods described herein.

[0015] Figure 1 The regenerative braking subsystem 112 shown includes an electric motor 126, a battery 128, and an inverter 130. In some embodiments, the left rear wheel 108 and the right rear wheel 110 are driven by the electric motor 126, as shown in FIG. Figure 1 As shown. In other embodiments, the left rear wheel 108 and the right rear wheel 110 are driven by separate motors (not shown). In some embodiments, the left front wheel 104 and the right front wheel 106 are similarly driven by respective motors (not shown). In some embodiments, the electric motor 126 operates on AC (alternating current) power, and the battery 128 stores DC (direct current) power. The inverter 130 converts the DC power stored in the battery 128 into AC power, which is used by the electric motor 126 to drive the left rear wheel 108 and the right rear wheel 110. In other embodiments, the electric motor 126 operates on DC (direct current) power.

[0016] When vehicle 100 is coasting (e.g., when accelerator pedal 120 is disengaged), regenerative braking subsystem 112 causes electric motor 126 to act as a generator, converting the kinetic energy of vehicle 100 into AC power. Inverter 130 converts the AC power generated by electric motor 126 into DC power for storage in battery 128. The act of generating AC power generates regenerative braking torque at electric motor 126, which is transmitted to one or more of the wheels (e.g., left rear wheel 108 and right rear wheel 110) to decelerate and / or stabilize vehicle 100. Inverter 130 regulates the amount of regenerative braking torque generated by electric motor 126.

[0017] Regenerative braking subsystem 112 is part of the overall braking system for vehicle 100, which includes other braking subsystems such as, for example, an ABS (anti-lock braking system). In some embodiments, the braking system of vehicle 100 includes a friction braking subsystem that utilizes friction braking force to inhibit movement of one or more wheels of vehicle 100 in order to slow and / or stop vehicle 100 (e.g., hydraulic brakes and / or air brakes). For example, some or all wheels may be equipped with brake pads that apply friction braking force that inhibits movement of rotors connected to the wheels.

[0018] Sensors 114 determine one or more properties of vehicle 100 and communicate information about those properties to other components of system 102 using, for example, electrical signals. Vehicle properties include, for example, the position of vehicle 100 or a portion or component of vehicle 100, the motion of vehicle 100 or a portion or component of vehicle 100, forces acting on vehicle 100 or a portion or component of vehicle 100, the proximity of vehicle 100 to other vehicles or objects (stationary or moving), yaw rate, sideslip angle, steering wheel angle, overlay angle, vehicle speed, longitudinal acceleration, and lateral acceleration. Sensors 114 may include, for example, vehicle control sensors (e.g., sensors that detect the position of accelerator pedal 120, brake pedal 122, and steering wheel position), wheel speed sensors, vehicle speed sensors, yaw sensors, force sensors, odometer sensors, and vehicle proximity sensors (e.g., cameras, radar, LIDAR, and ultrasonic). In some embodiments, in addition to the sensors 114, the system 102 includes a GNSS (Global Navigation Satellite System) receiver that determines the geospatial location (i.e., latitude, longitude, altitude, and speed) of the vehicle 100 based on received satellite radio frequency signals. The vehicle controller 118 can use this information in conjunction with the information received from the sensors 114 when controlling the vehicle 100.

[0019] Other vehicle systems 116 include controllers, sensors, actuators, etc., for controlling operational aspects of vehicle 100 (e.g., steering, acceleration, braking, gear shifting, etc.). Other vehicle systems 116 are configured to send and receive data related to the operation of vehicle 100 to and from regenerative braking subsystem 112 and / or vehicle controller 118.

[0020] Figure 2 is a block diagram of one example of the vehicle controller 118 . Figure 2 The illustrated vehicle controller 118 includes an electronic processor 202 (e.g., one or more microprocessors, application-specific integrated circuits [ASICs], system-on-chips [SOCs], etc.), memory 204, and an input / output interface 206. Memory 204 may be comprised of one or more non-transitory computer-readable media and include at least a program storage area and a data storage area. The program storage area and the data storage area may include a combination of different types of memory, such as read-only memory (ROM), random access memory (RAM) (e.g., dynamic RAM [DRAM], synchronous DRAM [SDRAM], etc.), electrically erasable programmable read-only memory (EEPROM), flash memory, or other suitable memory devices. Electronic processor 202 is coupled to memory 204 and input / output interface 206. Electronic processor 202 sends and receives information (e.g., from memory 204 and / or input / output interface 206) and processes the information by executing one or more software instructions or modules that can be stored in memory 204 or another non-transitory computer-readable medium. Software may include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. Electronic processor 202 is configured to retrieve from memory 204 and execute, among other things, software for regenerative braking control and for performing the methods described herein.

[0021] The input / output interface 206 transmits and receives information from devices external to the vehicle controller 118 (e.g., via one or more wired and / or wireless connections), such as components of the system 102, via the bus 124. The input / output interface 206 receives user input, provides system output, or a combination of both. The input / output interface 206 may also include other input and output mechanisms, which are not described herein for the sake of brevity and which may be implemented in hardware, software, or a combination of both.

[0022] It should be understood that although Figure 2Only a single example of the electronic processor 202, memory 204, and input / output interface 206 is shown, but alternative embodiments of the vehicle controller 118 may include multiple processing units, memory modules, and / or input / output interfaces. In some embodiments, the vehicle controller 118 is partially or entirely implemented on a semiconductor chip (e.g., a field programmable gate array [FPGA] semiconductor). In some embodiments, the vehicle controller 118 is included in the regenerative braking subsystem 112. For example, the vehicle controller 118 may be included in the inverter 130. In other embodiments, the vehicle controller 118 is included in one of the other vehicle systems 116. For example, the vehicle controller 118 may be included in a brake control module or an ABS module.

[0023] As described above, open-loop control of regenerative braking torque does not account for variables that affect vehicle deceleration behavior, such as vehicle mass. Vehicle controller 118 is configured to perform closed-loop control of regenerative braking torque by actively adjusting the regenerative braking torque to maintain a target vehicle deceleration rate. Closed-loop control of regenerative braking based on vehicle deceleration, as described herein, achieves consistent vehicle deceleration behavior without directly accounting for variables such as vehicle mass. Furthermore, when vehicle 100 is heavier, closed-loop control of regenerative braking enables the capture of additional kinetic energy due to the increased regenerative braking torque.

[0024] Figure 3 is a flow chart of an example method 300 for closed-loop control of regenerative braking in vehicle 100. Although method 300 is described in conjunction with system 102 as described herein, method 300 may be used with other systems and vehicles. Furthermore, method 300 may be modified or implemented differently from the specific example provided. As an example, method 300 is described as being performed by vehicle controller 118 and regenerative braking subsystem 112. However, it should be understood that in some embodiments, portions of method 300 may be performed by other devices or subsystems of system 102.

[0025] At block 302 , the regenerative braking subsystem 112 applies a first amount of regenerative braking torque. For example, the inverter 130 sends a power signal to the electric motor 126 , which causes the electric motor 126 to generate a certain amount of electric power, resulting in the first amount of regenerative braking torque being delivered to one or more wheels. In some embodiments, the vehicle controller 118 sends a control signal to the regenerative braking subsystem 112 indicating the first amount of regenerative torque. In some embodiments, the regenerative braking subsystem 112 is configured to apply the first amount of regenerative braking torque in response to receiving a control signal indicating that the accelerator pedal 120 is released (i.e., when the vehicle 100 begins to coast). For example, the vehicle controller 118 (or the regenerative braking subsystem 112) may receive a data signal from the accelerator pedal 120 (or from one or more sensors 114 ) indicating that the pedal position is less than a threshold percentage of the maximum engagement range (e.g., less than a threshold of 10%).

[0026] At block 304 , when the first amount of regenerative braking torque is applied, the current vehicle deceleration is determined. In some embodiments, the vehicle controller 118 determines the current vehicle deceleration based on data signals from one or more sensors 114 (e.g., accelerometers) that detect the current vehicle deceleration. Alternatively or additionally, the vehicle controller 118 determines the current vehicle deceleration based on changes in vehicle speed over time, as determined from multiple vehicle speed measurements. In some embodiments, the vehicle controller 118 receives data signals indicating the current vehicle speed from one or more sensors 114 (e.g., wheel speed sensors, motor speed sensors, etc.). Alternatively or additionally, the vehicle controller 118 receives data signals indicating the current vehicle speed from one or more other vehicle systems 116. As a first example, the ABS module may determine the current vehicle speed based on data signals received from one or more wheel speed sensors. As a second example, the GNSS receiver may determine the current vehicle speed based on changes in vehicle position over time.

[0027] At block 306 , the difference between the current vehicle deceleration and the target vehicle deceleration is determined. For example, the vehicle controller 118 determines whether the current vehicle deceleration is greater than, less than, or equal to the target vehicle deceleration. Examples of determining the target vehicle deceleration are described further below. At block 308 , a second amount of regenerative braking torque is set to reduce the difference between the current vehicle deceleration and the target vehicle deceleration. For example, in some embodiments, the vehicle controller 118 is configured to set the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and to set the second amount of regenerative braking torque to be lower than the first amount of regenerative braking torque when the current vehicle deceleration is higher than the target vehicle deceleration. In some embodiments, the vehicle controller 118 is configured to set the second amount of regenerative braking torque to be equal to the first amount of regenerative braking torque when the difference between the current vehicle deceleration and the target deceleration is lower than a threshold. For example, the difference between the current vehicle deceleration and the target deceleration may be so small that adjusting the regenerative braking torque will not further reduce the difference.

[0028] At block 310, a second amount of regenerative braking torque is applied using the regenerative braking subsystem 112. For example, the inverter 130 sends a control signal to the electric motor 126, which causes the electric motor 126 to generate an amount of electric power that results in the second amount of regenerative braking torque being delivered to one or more wheels. In some embodiments, the vehicle controller 118 sends a control signal to the regenerative braking subsystem 112 indicating the second amount of regenerative torque.

[0029] In some embodiments, the method 300 loops and returns to block 304 to determine a new (or updated) current vehicle deceleration when the second amount of regenerative braking torque is applied. For example, the vehicle controller 118 can be configured to continuously (or intermittently) adjust the amount of regenerative braking torque applied by the regenerative braking subsystem 112 to minimize the difference between the current vehicle deceleration and the target vehicle deceleration.

[0030] In some embodiments, the vehicle controller 118 sets the target vehicle deceleration based at least in part on the position of the accelerator pedal 120. For example, as the position of the accelerator pedal 120 decreases toward its resting position, the vehicle controller 118 may increase the target vehicle deceleration. In some embodiments, the vehicle controller 118 uses a lookup table stored in the memory 204 to determine the target vehicle deceleration based on the position of the accelerator pedal 120. The lookup table may include other input variables, such as vehicle speed.

[0031] Alternatively or additionally, in some embodiments, the vehicle controller 118 sets the target vehicle deceleration based at least in part on the position of the brake pedal 120. For example, as the position of the accelerator pedal 120 increases away from its resting position, the vehicle controller 118 may increase the target vehicle deceleration.

[0032] Alternatively or additionally, in some embodiments, the vehicle controller 118 sets a target vehicle deceleration to prevent the brake lights (i.e., stop lights) of the vehicle 100 from illuminating when the vehicle 100 is coasting. Many countries require that the vehicle be decelerated when it exceeds a threshold vehicle deceleration (e.g., more than -1.3 m / s 2 ), the vehicle's brake lights must be on. Therefore, in some embodiments, the vehicle controller 118 sets the target vehicle deceleration to be less than the threshold vehicle deceleration when the brake lights are on.

[0033] Alternatively or additionally, in some implementations, the vehicle controller 118 sets the target vehicle deceleration based on a braking intervention. As a first example, a trajectory control module of the vehicle 100 may determine that a braking intervention is required to address a detected external road condition. As a second example, an ABS module of the vehicle 100 may determine that a braking intervention is required to address a wheel slip condition.

[0034] Various aspects of the present disclosure may employ any one or more of the following exemplary configurations (ECs).

[0035] EC (1) A system for closed-loop control of regenerative braking in a vehicle, the system comprising: a regenerative braking subsystem; a vehicle controller configured to: command the regenerative braking subsystem to apply a first amount of regenerative braking torque, determine a current vehicle deceleration when applying the first amount of regenerative braking torque, determine a difference between the current vehicle deceleration and a target vehicle deceleration, set a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration, and command the regenerative braking subsystem to apply the second amount of regenerative braking torque.

[0036] EC(2) A system according to EC(1), wherein the vehicle controller is further configured to: set the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and set the second amount of regenerative braking torque to be lower than the first amount of regenerative braking torque when the current vehicle deceleration is higher than the target vehicle deceleration.

[0037] EC(3) The system of EC(1) or EC(2), wherein the target vehicle deceleration is less than a threshold vehicle deceleration at which a brake light of the vehicle is illuminated.

[0038] EC(4) A system according to any one of EC(1) to EC(3), wherein the vehicle controller is further configured to command the regenerative braking subsystem to apply the first amount of regenerative braking torque in response to receiving a control signal indicating that a vehicle accelerator pedal is released.

[0039] EC(5) A system according to any one of EC(1) to EC(4), wherein the vehicle controller is further configured to determine the target vehicle deceleration based at least in part on a position of an accelerator pedal of the vehicle or a position of a brake pedal of the vehicle.

[0040] EC (6) A system according to any one of EC (1) to EC (5), wherein the vehicle controller is further configured to determine a current vehicle deceleration based on a plurality of vehicle speed measurements.

[0041] EC(7) The system of any EC(6), further comprising one or more sensors positioned on the vehicle and configured to sense a plurality of vehicle speed measurements, wherein the one or more sensors include at least one selected from the group consisting of: a wheel speed sensor, a motor speed sensor, and an engine speed sensor.

[0042] EC (8) A method for closed-loop control of regenerative braking in a vehicle, the method comprising: applying a first amount of regenerative braking torque using a regenerative braking subsystem of the vehicle; determining a current vehicle deceleration when the first amount of regenerative braking torque is applied; determining a difference between the current vehicle deceleration and a target vehicle deceleration; setting a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration; and applying the second amount of regenerative braking torque using the regenerative braking subsystem.

[0043] EC (9) The method according to EC (8) further includes: setting the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and setting the second amount of regenerative braking torque to be lower than the first amount of regenerative braking torque when the current vehicle deceleration is higher than the target vehicle deceleration.

[0044] EC (10) The method of one of EC (8) or EC (9), wherein the target vehicle deceleration is less than a threshold vehicle deceleration at which a brake light of the vehicle is illuminated.

[0045] EC (11) The method of any one of EC (8) to EC (10), further comprising applying a first amount of regenerative braking torque using the regenerative braking subsystem in response to receiving a control signal indicating that an accelerator pedal of the vehicle is released.

[0046] EC (12) The method according to any one of EC (8) to EC (11), further comprising determining a target vehicle deceleration based on a vehicle speed measurement and a position of a vehicle accelerator pedal.

[0047] EC (13) The method according to any one of EC (8) to EC (12), further comprising determining a current vehicle deceleration based on a plurality of vehicle speed measurements.

[0048] EC (14) A vehicle comprising: a regenerative braking subsystem; and a vehicle controller configured to: command the regenerative braking subsystem to apply a first amount of regenerative braking torque, determine a current vehicle deceleration when applying the first amount of regenerative braking torque, determine a difference between the current vehicle deceleration and a target vehicle deceleration, set a second amount of regenerative braking torque to reduce the difference between the current vehicle deceleration and the target vehicle deceleration, and command the regenerative braking subsystem to apply the second amount of regenerative braking torque.

[0049] EC(15) A vehicle according to EC(14), wherein the vehicle controller is further configured to: set the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and set the second amount of regenerative braking torque to be lower than the first amount of regenerative braking torque when the current vehicle deceleration is higher than the target vehicle deceleration.

[0050] EC (16) The vehicle according to EC (14) or EC (15), wherein the target vehicle deceleration is less than a threshold vehicle deceleration at which a brake light of the vehicle is illuminated.

[0051] EC(17) A vehicle according to any one of EC(14) to EC(16), wherein the vehicle controller is further configured to command the regenerative braking subsystem to apply the first amount of regenerative braking torque in response to receiving a control signal indicating that the vehicle accelerator pedal is released.

[0052] EC(18) A vehicle according to any one of EC(14) to EC(17), wherein the vehicle controller is further configured to determine the target vehicle deceleration based at least in part on a position of an accelerator pedal of the vehicle or a position of a brake pedal of the vehicle.

[0053] EC(19) A vehicle according to any one of EC(14) to EC(18), wherein the vehicle controller is further configured to determine a current vehicle deceleration based on a plurality of vehicle speed measurements.

[0054] EC(20) The vehicle of EC(19), further comprising one or more sensors positioned on the vehicle and configured to sense a plurality of vehicle speed measurements, wherein the one or more sensors include at least one selected from the group consisting of: a wheel speed sensor, a motor speed sensor, and an engine speed sensor.

[0055] In the foregoing description, specific embodiments have been described. However, those skilled in the art will appreciate that various modifications and variations may be made without departing from the scope of the claims set forth below. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of this disclosure.

[0056] It should be understood that the phraseology and terminology used herein are for descriptive purposes and should not be construed as limiting. The terms "mounted," "connected," and "coupled" are used broadly and encompass both direct and indirect mountings, connections, and couplings. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings and may include electrical connections or couplings, whether direct or indirect. Furthermore, electronic communication and notification may be performed using any known means, including wired connections, wireless connections, and the like.

[0057] It should also be noted that the present disclosure can be implemented using a variety of hardware- and software-based devices and a variety of different structural components. It should also be noted that a variety of hardware- and software-based devices and a variety of different structural components can be used to implement the present disclosure. Furthermore, it should be understood that embodiments of the present disclosure may include hardware, software, and electronic components or modules, and for discussion purposes, these components may be illustrated and described as if most components are implemented solely in hardware. However, those skilled in the art, upon reading this detailed description, will recognize that, in at least one embodiment, the electronic-based aspects of the present disclosure can be implemented in software (e.g., stored on a non-transitory computer-readable medium) that can be executed by one or more processors. Therefore, it should be noted that the present disclosure can be implemented using a variety of hardware- and software-based devices and a variety of different structural components. For example, the "control unit" and "controller" described in this specification may include one or more processors, one or more memory modules including non-transitory computer-readable media, one or more input / output interfaces, and various connections connecting components (e.g., a system bus).

[0058] For ease of description, some or all of the example systems presented herein are described with a single sample of each of their components. Some examples may not depict or illustrate all components of the system. Other example embodiments may include more or fewer of each of the illustrated components, may combine some components, or may include additional or alternative components.

[0059] In this document, relative terms such as first and second, top and bottom, etc., may be used solely to distinguish one entity or action from another and do not necessarily require or imply any actual relationship or order between such entities or actions. The terms "comprises," "comprising," "has," "having," "includes," "including," "contains," "containing," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises, has, contains, or includes a list of elements includes not only those elements but also may include additional elements not expressly listed or inherent to such process, method, article, or apparatus. An element beginning with "comprises...an," "has...an," "includes...an," or "containing...an" does not, without more limitations, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises, has, contains, or includes the element. The terms "a" and "an" are defined as one or more unless expressly stated otherwise herein. The terms "substantially," "essentially," "approximately," "about," or any other versions thereof, are defined as approximating to what one of ordinary skill in the art understands, and in one non-limiting embodiment, are defined as within 10%, in another embodiment within 5%, and in another embodiment within 1%, and in another embodiment within 0.5%. The term "coupled," as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. A device or structure that is "configured" in a particular way is configured in at least that way, but may also be configured in ways not listed.

[0060] Thus, the present disclosure provides, among other things, systems, methods, and vehicles for closed-loop control of regenerative braking. Various features and advantages are set forth in the following claims.

Claims

1. A system for closed-loop control of regenerative braking in a vehicle, the system comprising: regenerative braking subsystem; as well as A vehicle controller configured to: commanding the regenerative braking subsystem to apply a first amount of regenerative braking torque, determining a current vehicle deceleration when the first amount of regenerative braking torque is applied, determining a difference between the current vehicle deceleration and a target vehicle deceleration, setting a second amount of regenerative braking torque to reduce a difference between the current vehicle deceleration and the target vehicle deceleration, and commanding the regenerative braking subsystem to apply the second amount of regenerative braking torque, The target vehicle deceleration is less than a threshold vehicle deceleration, at which the brake lights of the vehicle are turned on.

2. The system according to claim 1, wherein: The vehicle controller is further configured to: setting the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and When the current vehicle deceleration is higher than the target vehicle deceleration, the second amount of regenerative braking torque is set to be lower than the first amount of regenerative braking torque.

3. The system according to claim 1, wherein: The vehicle controller is further configured to command the regenerative braking subsystem to apply the first amount of regenerative braking torque in response to receiving a control signal indicative of a release of an accelerator pedal of the vehicle.

4. The system according to claim 1, wherein: The vehicle controller is further configured to determine a target vehicle deceleration based at least in part on an accelerator pedal position of the vehicle or a brake pedal position of the vehicle.

5. The system according to claim 1, wherein The vehicle controller is further configured to determine the current vehicle deceleration based on a plurality of vehicle speed measurements.

6. The system of claim 5, further comprising one or more sensors positioned on the vehicle and configured to sense the plurality of vehicle speed measurements, wherein The one or more sensors include at least one selected from the group consisting of: a wheel speed sensor, a motor speed sensor, and an engine speed sensor.

7. A method for closed-loop control of regenerative braking in a vehicle, the method comprising: applying a first amount of regenerative braking torque with a regenerative braking subsystem of the vehicle; determining a current vehicle deceleration when the first amount of regenerative braking torque is applied; determining a difference between the current vehicle deceleration and a target vehicle deceleration; setting a second amount of regenerative braking torque to reduce a difference between the current vehicle deceleration and the target vehicle deceleration; as well as applying the second amount of regenerative braking torque using the regenerative braking subsystem, The target vehicle deceleration is less than a threshold vehicle deceleration, at which the brake lights of the vehicle are turned on.

8. The method according to claim 7, further comprising: setting the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and When the current vehicle deceleration is higher than the target vehicle deceleration, the second amount of regenerative braking torque is set to be lower than the first amount of regenerative braking torque. 9 . The method of claim 7 , further comprising applying a first amount of regenerative braking torque using the regenerative braking subsystem in response to receiving a control signal indicative of an accelerator pedal release of the vehicle. 10 . The method of claim 7 , further comprising determining the target vehicle deceleration based on a vehicle speed measurement and a position of a vehicle accelerator pedal.

11. The method of claim 7, further comprising determining the current vehicle deceleration based on a plurality of vehicle speed measurements.

12. A vehicle comprising: regenerative braking subsystem; as well as A vehicle controller configured to: commanding the regenerative braking subsystem to apply a first amount of regenerative braking torque, determining a current vehicle deceleration when the first amount of regenerative braking torque is applied, determining a difference between the current vehicle deceleration and a target vehicle deceleration, setting a second amount of regenerative braking torque to reduce a difference between the current vehicle deceleration and the target vehicle deceleration, and commanding the regenerative braking subsystem to apply a second amount of regenerative braking torque, The target vehicle deceleration is less than a threshold vehicle deceleration, at which the brake lights of the vehicle are turned on.

13. The vehicle according to claim 12, wherein: The vehicle controller is further configured to: setting the second amount of regenerative braking torque to be higher than the first amount of regenerative braking torque when the current vehicle deceleration is lower than the target vehicle deceleration, and When the current vehicle deceleration is higher than the target vehicle deceleration, the second amount of regenerative braking torque is set to be lower than the first amount of regenerative braking torque.

14. The vehicle according to claim 12, wherein: The vehicle controller is further configured to command the regenerative braking subsystem to apply the first amount of regenerative braking torque in response to receiving a control signal indicative of an accelerator pedal release of the vehicle.

15. The vehicle of claim 12, wherein: The vehicle controller is further configured to determine the target vehicle deceleration based at least in part on an accelerator pedal position of the vehicle or a brake pedal position of the vehicle.

16. The vehicle of claim 12, wherein: The vehicle controller is further configured to determine the current vehicle deceleration based on a plurality of vehicle speed measurements.

17. The vehicle of claim 16, further comprising one or more sensors positioned on the vehicle and configured to sense a plurality of vehicle speed measurements, wherein The one or more sensors include at least one selected from the group consisting of: a wheel speed sensor, a motor speed sensor, and an engine speed sensor.

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