Control scheme for controlling acceleration of a vehicle

Abstract

Aspects of the invention relate to a control system (100) for controlling a torque output of a torque system (240) of a vehicle (900) to control acceleration of the vehicle on a hill, the control system (100) comprising one or more processors (120) collectively configured to: receive a torque demand signal (160) indicative of a requested torque; receive a vehicle speed signal (162) indicative of a speed of the vehicle (900); determine an expected acceleration of the vehicle (900) from the torque demand signal (160) and the vehicle speed signal (162), wherein the expected acceleration is indicative of an acceleration of the vehicle (900) expected in response to the requested torque being provided to the vehicle (900) when the vehicle (900) is on flat road surface; determine an actual acceleration of the vehicle (900) from the vehicle speed; compare the expected acceleration and the actual acceleration of the vehicle (900); and output a torque control signal (170) to control the torque output (231) of the torque system (240) in dependence on the comparison. Aspects of the invention also relate to a torque system (240) incorporating the control system (100) and a powertrain (210), a vehicle (900) containing the control system (100), and a method (300) of controlling a torque system (240) of a vehicle (900).

Description

Technical Field

[0001] This disclosure relates to a control scheme for controlling the acceleration of a vehicle. Aspects of the invention relate to a control system for controlling the torque output of a vehicle's torque system to control the vehicle's acceleration on a slope, the vehicle's torque system, the vehicle, and a method for controlling the control system for controlling the torque output of the vehicle's torque system. Background Technology

[0002] Vehicles are known to include systems for providing torque to drive the vehicle. Torque demand is typically based on the driver's needs, such as determining whether the driver wishes to change the vehicle's acceleration by measuring the positions of the accelerator and brake pedals. Systems are also known to provide vehicles that introduce additional positive torque to accelerate the vehicle beyond any acceleration requested by the driver using the accelerator pedal. Such systems may include: a creep function that maintains a low vehicle speed without any pedal input from the driver; or a system for one-pedal driving that introduces positive or negative torque to control the vehicle's speed, allowing the driver to operate the vehicle using only the accelerator pedal. For example, a one-pedal driving mode could introduce torque into the system when the vehicle is traveling uphill to control deceleration when the driver removes pressure from the accelerator pedal; and could remove torque from the system when the vehicle is traveling downhill to bring the vehicle to a stop when the driver removes pressure from the accelerator pedal. Managing the addition of positive torque to the vehicle is important, and therefore, conventional systems are constrained to adding a limited amount of positive torque or operating only at low vehicle speeds.

[0003] The purpose of this invention is to address one or more of the disadvantages associated with the prior art. Summary of the Invention

[0004] The present invention provides a control scheme for controlling the acceleration of a vehicle. The present invention relates to a control system for controlling the torque output of a vehicle's torque system to control the vehicle's acceleration on a slope, as claimed in the appended claims; a vehicle's torque system; a vehicle; and a method for controlling the control system for controlling the torque output of the vehicle's torque system.

[0005] According to one aspect of the present invention, a control system is provided for controlling the torque output of a vehicle's torque system to adjust the torque output based on the vehicle's speed and torque demand, thereby compensating for the difference between the vehicle's expected acceleration and actual acceleration when the vehicle is traveling on a flat road.

[0006] According to one aspect of the invention, a control system for controlling the torque output of a vehicle's torque system to control the vehicle's acceleration on a slope is provided. The control system includes one or more processors configured to: receive a torque demand signal indicating a requested torque; receive a vehicle speed signal indicating the vehicle's speed; determine a desired acceleration of the vehicle based on the torque demand signal and the vehicle speed signal, wherein the desired acceleration indicates the vehicle's expected acceleration in response to providing the requested torque when the vehicle is on a flat road surface; determine the actual acceleration of the vehicle based on the vehicle speed; compare the desired acceleration and the actual acceleration of the vehicle; and output a torque control signal based on the comparison to control the torque output of the torque system.

[0007] When the expected vehicle acceleration in response to a requested torque applied on a flat road surface does not match the actual vehicle acceleration, the control system adjusts the torque output from the torque system. This may be due to several example scenarios, such as gradient, coast-to-stop features, or adaptive pedal aggression features on inclines. For example, the coast-to-stop feature might request a torque that causes the vehicle to accelerate beyond the expected acceleration based on the accelerator pedal position. The coast-to-stop feature can be a vehicle characteristic that controls the vehicle to exhibit specific behaviors that require adding or removing torque from the torque system's output. For example, when a one-pedal driving mode is enabled and the driver is driving uphill without using the brakes to decelerate the vehicle, the coast-to-stop feature might introduce positive torque to increase torque output, thus preventing the vehicle from rolling backwards in the downhill direction. If the coast-to-stop feature adds too much positive torque, the vehicle may accelerate unpredictably. Therefore, the control system prevents unintended acceleration by removing the positive torque. Thus, the driver is not subjected to unwanted acceleration. Furthermore, since the control system works to prevent undesirable over-acceleration, the amount of positive torque that can be introduced into the torque system by features such as coasting to a stop feature, creep feature, and adaptive pedal progressive feature can be increased or removed.

[0008] The torque output of a system can be the sum of the positive torque output by a torque generator (such as an engine or motor) and the negative torque output by a braking system. Therefore, torque output can represent the net torque applied to the vehicle to accelerate or decelerate it.

[0009] Optionally, the expected acceleration of the vehicle on a flat road surface indicates the vehicle acceleration calculated when the torque corresponding to the torque demand signal is applied to the vehicle traveling at a certain vehicle speed on the flat road surface. Therefore, the control scheme determines the expected acceleration of the vehicle in the absence of any influence from the system introducing positive torque or road surface gradient. This expected acceleration can then be compared with the vehicle's actual acceleration to determine whether the torque output of the torque system needs adjustment.

[0010] The control system includes one or more controllers, which collectively include: at least one electronic processor having an electrical input for receiving an input signal; and at least one memory device electrically coupled to the at least one electronic processor and storing instructions on the at least one memory device; wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon to perform the following operations: receiving a torque demand signal indicating a requested torque; receiving a vehicle speed signal indicating the speed of the vehicle; determining a expected acceleration of the vehicle based on the torque demand signal and the vehicle speed signal, wherein the expected acceleration indicates: the expected acceleration of the vehicle in response to providing the requested torque to the vehicle when the vehicle is on a flat road surface; determining the actual acceleration of the vehicle based on the vehicle speed; comparing the expected acceleration and the actual acceleration of the vehicle; and outputting a torque control signal based on the comparison to control the torque output of the torque system.

[0011] Optionally, a flat road surface includes a road surface with a zero percentage slope.

[0012] Optionally, the actual acceleration exceeding the expected acceleration indicates that the vehicle is on a slope.

[0013] Optionally, the torque demand signal indicates the position of one or more pedals in the vehicle.

[0014] Optionally, the pedal position indicates the driver's torque request.

[0015] Optionally, the relationship between pedal position and requested torque is determined based on the vehicle's gradient. That is, the pedal position may correspond to a specific amount of torque requested by the driver, and the amount of torque for different pedal positions can vary depending on the gradient of the road surface on which the vehicle is located. For example, the vehicle may include features such as an adaptive pedal progressive mode, in which the requested torque increases more rapidly with pedal depressing when the vehicle is on an uphill slope than when the vehicle is on a flat surface, thereby reducing the need for the driver to depress the pedal further to accelerate the vehicle uphill compared to a flat surface.

[0016] Optionally, the requested torque may include a torque component requested by the vehicle system in addition to the torque identified as the requested torque based on the accelerator pedal position. For example, the requested torque may include a torque component requested by a coasting-to-stop feature.

[0017] Optionally, one or more processors are configured to output control signals to control the torque output of the torque system, such that the actual acceleration of the vehicle is controlled to reduce the difference between the actual acceleration and the expected acceleration of the vehicle. Advantageously, the torque output is controlled to prevent unintended acceleration of the vehicle due to the introduction of positive torque characteristics.

[0018] Optionally, one or more processors are configured to output control signals to control the torque output of the torque system, such that the actual acceleration of the vehicle is controlled to be equal to the vehicle's intended acceleration. Advantageously, the vehicle's acceleration corresponds more closely to the driver's intention.

[0019] Optionally, one or more processors are configured to: determine that the actual acceleration of the vehicle exceeds the expected acceleration of the vehicle; and based on the determination, output a torque control signal to reduce torque from the torque output of the torque system.

[0020] Optionally, one or more processors are configured to: determine the difference between the actual acceleration of the vehicle and the expected acceleration of the vehicle; and, if the actual acceleration of the vehicle exceeds the expected acceleration of the vehicle, output a torque control signal to reduce torque from the torque output of the torque system, wherein the amount of torque to be removed is determined based on the determined difference.

[0021] Optionally, one or more processors are jointly configured to determine the vehicle's expected acceleration based on the acceleration torque component, wherein the processors are jointly configured to subtract one or more of the road load torque or braking torque from the requested torque of the torque demand signal to determine the acceleration torque component; the road load torque includes a certain amount of torque corresponding to the resistance to vehicle motion; and the road load torque is determined based on the vehicle speed. Advantageously, the vehicle's current state is considered when determining the expected acceleration, and the opposing force relative to the vehicle's motion is also considered when determining the expected acceleration.

[0022] Optionally, the road load torque includes a certain amount of torque required to maintain the vehicle's speed. In this implementation, the resistance to vehicle motion is based on one or more of rolling resistance, air resistance, and gravity.

[0023] Advantageously, by considering only the acceleration torque, the control system will not erroneously detect that the difference between the actual and expected acceleration is eliminated due to driver braking. That is, when the driver brakes, the actual acceleration may decrease to less than the expected acceleration, and the system may incorrectly determine that the over-torque has been resolved without considering the braking torque.

[0024] Optionally, one or more processors are configured to convert acceleration torque into the vehicle’s expected acceleration based on a predetermined tire rolling radius and a predetermined vehicle mass.

[0025] Optionally, one or more processors are configured together to determine the vehicle's expected acceleration based on the maximum expected acceleration value.

[0026] Optionally, one or more processors are configured together to determine the vehicle's expected acceleration based on the expected minimum acceleration.

[0027] Optionally, one or more processors are configured to determine the vehicle's expected acceleration based on one or more of the expected maximum and expected minimum acceleration values.

[0028] Optionally, the expected maximum acceleration is determined based on vehicle speed. Advantageously, at low speeds, the control system can allow positive torque to increase the acceleration to 0 (or slightly above 0) to prevent the vehicle from rolling backward. At higher speeds, a deceleration request is detected as a trigger for controlling torque output.

[0029] Optionally, one or more processors are configured to output a torque control signal based on the minimum torque output of the torque system; and the minimum torque output of the torque system is based on one or more of the following: creep torque associated with the vehicle's creep function; requested torque; and zero torque.

[0030] Optionally, the creep torque includes a certain amount of torque requested by the vehicle's creep function; wherein, when the requested torque is zero, the vehicle's creep function requests creep torque to maintain the vehicle's creep speed.

[0031] Optionally, the creep speed is between 0 kph and 6 kph. Advantageously, embodiments of the invention complement other vehicle functions by providing adaptive targets for torque and / or vehicle acceleration based on the functions of other vehicle characteristics.

[0032] Optionally, one or more processors are configured to generate a torque control signal based on one or more of the following: a proportional term determined by comparing the actual acceleration of the vehicle with the expected acceleration of the vehicle and a first gain factor; and an integral term determined by comparing the actual acceleration of the vehicle with the expected acceleration of the vehicle, a second gain factor, and the integrator execution rate.

[0033] Optionally, the first gain factor is implemented as a curve that depends on the current difference between the vehicle's expected acceleration and its actual acceleration. This allows the first gain factor to increase when a large difference exists, resulting in a stronger response from the control system.

[0034] Optionally, the second gain factor is a different curve than the first gain factor. However, it should be understood that the first and second gain factors share the same input, which is the current difference between the vehicle's expected acceleration and its actual acceleration. This allows the integral term to behave differently for different amounts of difference.

[0035] Optionally, the scaling term is determined by multiplying the difference between the vehicle’s actual acceleration and the vehicle’s expected acceleration by a first gain factor.

[0036] Optionally, the proportional term is saturated between 0 and the negative controller allowable value. This is to prevent the control system from adding positive torque back into the system, which could be undesirable for the vehicle's driver.

[0037] Advantageously, according to these embodiments, the integrator has a memory of the previous difference between the vehicle's actual acceleration and its expected acceleration. Therefore, the control system can correct steady-state controller errors based on the difference between the vehicle's actual and expected acceleration over time.

[0038] Optionally, the integral term is also determined based on the maximum integral term and the previous integral term, the previous integral term including the integral term used to determine the integral term in the previous execution; and the maximum integral term is determined based on the previous integral term and the integrator execution rate.

[0039] Optionally, the integral term is determined by multiplying the difference between the vehicle's actual acceleration and the vehicle's expected acceleration by a second gain factor and an execution rate, adding the result of the multiplication to the previous integral term, and limiting the result of the addition based on the maximum integral term.

[0040] Optionally, the integral term is saturated between 0 and the negative controller allowable value. This is to prevent the control system from adding positive torque back into the system, which may be undesirable for the vehicle's driver.

[0041] Optionally, one or more processors are configured to, based on the comparison output torque control signal, redistribute at least a portion of the requested torque to the vehicle's brakes. Advantageously, even when the positive torque in the torque output of the torque system is reduced, vehicle rollback (i.e., the vehicle unexpectedly rolling backward on a slope) can be prevented when the driver does not press down on the accelerator.

[0042] Optionally, one or more processors are configured to: generate a coasting-to-stop control signal based on a torque control signal; and output the coasting-to-stop control signal to a coasting-to-stop controller to control the torque demand of the coasting-to-stop controller.

[0043] Optionally, the coast-to-stop controller is configured to operate the vehicle's coast-to-stop function; wherein the vehicle's coast-to-stop function includes requesting positive torque to activate the vehicle's one-pedal driving mode.

[0044] Advantageously, the positive torque removed from the torque output of the torque system will not be reintroduced by downstream controllers or functions (such as coast to stop controllers).

[0045] According to another aspect of the invention, a torque system for a vehicle is provided, the torque system including a control system and a powertrain according to any of the foregoing statements, the powertrain being configured to generate and output torque output according to a torque control signal.

[0046] According to another aspect of the invention, a vehicle is provided that includes any of the aforementioned control systems or torque systems.

[0047] According to another aspect of the present invention, a method is provided for controlling the torque output of a torque system of a vehicle to control the acceleration of the vehicle on a slope, the method comprising: receiving a torque demand signal indicating a requested torque; receiving a vehicle speed signal indicating the speed of the vehicle; determining a desired acceleration of the vehicle based on the torque demand signal and the vehicle speed signal, wherein the desired acceleration indicates the expected acceleration of the vehicle in response to providing the requested torque to the vehicle when the vehicle is on a flat road surface; determining an actual acceleration of the vehicle based on the vehicle speed; comparing the desired acceleration and the actual acceleration of the vehicle; and outputting a torque control signal based on the comparison to control the torque output of the torque system.

[0048] According to another aspect of the invention, a computer-readable instruction is provided, which, when executed by a computer, is configured to perform the method.

[0049] Within the scope of this application, it is expressly intended that various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their various features, may be adopted independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, unless such features are incompatible. The applicant reserves the right to amend any originally filed claim or accordingly file any new claim, including the right to modify any originally filed claim to be dependent on any other claim and / or incorporated into any feature of any other claim, although not initially claimed in this manner. Attached Figure Description

[0050] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0051] Figure 1 A block diagram of the illustrated control system is shown;

[0052] Figure 2 A block diagram of the illustrated torque system is shown.

[0053] Figures 3 to 7 A flowchart illustrating the method of operating the control system is shown.

[0054] Figure 8 The simulation graphs of the method for operating the control system illustrated are shown; and

[0055] Figure 9 A vehicle according to an embodiment of the present invention is shown. Detailed Implementation Plan

[0056] This disclosure relates to control systems for torque systems and methods for controlling such control systems. The control system is configured to control the torque output of the torque system and, in particular, to determine whether to remove torque from the torque output of the torque system. It is known to provide vehicles with the characteristic of introducing positive torque exceeding the amount explicitly requested by the driver (typically through the driver's control of the accelerator pedal). These systems are designed to support the driver and improve the driving experience by modifying vehicle control based on various conditions such as road surface gradient or one-pedal driving mode. However, it is important that these systems do not introduce excessive positive torque that may be undesirable to the driver. Therefore, these systems are generally constrained in terms of the addition of positive torque to prevent unintended vehicle acceleration. The present invention relates to methods and apparatus for monitoring vehicle speed and torque requested by the vehicle's driver, and controlling the torque output of the vehicle's torque system based on a comparison of the vehicle's actual acceleration with the expected acceleration of the vehicle as if it were on a flat road surface. By determining the expected acceleration of the vehicle and comparing it with the actual acceleration, the control system can control the torque system to reduce positive torque from the torque output, thereby preventing unintended acceleration of the vehicle beyond the driver's reasonable expectations. Various examples of the present invention are described below and include methods and apparatus for: determining a desired acceleration of a vehicle, comparing the desired acceleration of the vehicle with the actual acceleration of the vehicle, and generating and transmitting one or more torque control signals to control the torque output of the vehicle's torque system.

[0057] Vehicles typically have multiple wheels, such as four. In some examples, vehicles are equipped with a traction control system that manages the wheel speeds of each wheel to optimize the driver's experience. Vehicle speed signals can be derived from the average wheel speeds or through other means such as GPS, vision sensors, or other sensors.

[0058] This article refers to the appendix Figure 1 A control system 100 according to an embodiment of the present invention is described herein, and reference is made herein to the appendix. Figure 2 A torque system 240 of a vehicle 900 according to an embodiment of the present invention is described. For example... Figure 9 As shown, the control system 100 and / or torque system 240 (with components 210, 220 further described below) can be installed in the vehicle 900.

[0059] Reference Figure 1 This illustrates a torque control system 240, for example... Figure 2 The control system 100 of the torque system 240 shown below will be described in detail.

[0060] like Figure 1The control system 100 shown includes a controller 110; however, it should be understood that this is merely exemplary. The controller 110 includes a processing device 120 and a memory device 130. The processing device 120 may be one or more electronic processing devices 120, which are operatively capable of executing computer-readable instructions. The memory device 130 may be one or more memory devices 130. The memory device 130 is electrically coupled to the processing device 120. The memory device 130 is configured to store instructions, and the processing device 120 is configured to access the memory device 130 and execute the instructions stored thereon.

[0061] Controller 110 includes an input device 140 and an output device 150. Input device 140 may include electrical inputs to controller 110. Output device 150 may include electrical outputs to controller 110. Input device 140 is arranged to receive one or more input signals. Input device 140 is arranged to receive at least a torque demand signal 160 indicating a requested torque and a vehicle speed signal 162 indicating the speed of vehicle 900. Torque demand signal 160 may indicate a requested torque. The requested torque includes a certain amount of torque and may correspond to the pedal position of the accelerator pedal and / or brake pedal. The requested torque may be provided unaffected by incline, single-pedal driving mode, adaptive pedal progressive mode, etc. (i.e., may simply represent driver input on pedals, etc.), or the requested torque may be provided including one or more torque components corresponding to one or more of these effects. When requesting a pedal position corresponding to the accelerator pedal, the requested torque may include positive torque, and when requesting a pedal position corresponding to the brake pedal, the requested torque may include negative torque. It should be understood that the requested torque can be the net torque as the sum of the positive and negative torques requested by the driver, although it is unlikely that the driver would request both positive and negative torques at the same time.

[0062] Processing device 120 is configured to determine the expected acceleration of vehicle 900 based on torque demand signal 160 and vehicle speed signal 162. Expected acceleration indicates the acceleration of vehicle 900 expected when it is on a flat road surface in response to providing the requested torque to vehicle 900. It should be understood that a flat road surface includes a road surface with a slope of zero percent or close to zero percent. In some examples, the expected acceleration is determined using one or more assumptions to reflect the scenario where vehicle 900 is on a flat road surface; however, it should be understood that in this example, control system 100 is not actually certain whether vehicle 900 is on a flat road surface. That is, processing device 120 can determine the expected acceleration as if vehicle 900 were on a flat road surface without knowing or measuring the road surface slope. In another example, control system 100 can determine or receive information indicating the slope of the road surface in the vehicle's position.

[0063] In some examples, the expected acceleration can be determined by determining the acceleration torque based on the driver's torque demand (i.e., the requested torque of the torque demand signal 160). The driver's torque demand can correspond to the position of the accelerator pedal. It should be understood that in some examples, a greater depress of the accelerator pedal by the driver corresponds to a greater demand for torque. In some examples, the driver's torque demand can be based on the position of the accelerator pedal and a scaling factor. For example, a progressive pedal mode (or adaptive progressive pedal mode) can be provided in which the driver's torque demand scales more rapidly with the pedal position. In this example, vehicle 900 can be configured such that when the accelerator pedal is depressed by the driver, the torque demand increases compared to the torque demand at the same accelerator pedal position when progressive pedal mode is off. As will be understood, progressive pedal mode can be activated in several ways. For example, progressive pedal mode can be activated or deactivated based on user settings, road surface gradient, vehicle speed, or any other suitable means. In some examples, for reduced demand, driver demand on the plane can be filtered (excluding any influence from anti-rollover features or progressive pedaling patterns). In this example, processing unit 120 ensures that unexpected acceleration during normal operation is not falsely detected because there is a delay between the torque request decreasing and the actual vehicle acceleration decreasing to the expected level.

[0064] Processing device 120 can also be configured to determine the road load torque based on the vehicle speed indicated by vehicle speed signal 162. The road load torque can indicate the torque requirement at the vehicle speed to overcome the opposing force against the motion relative to the vehicle 900. It should be understood that the opposing force against the motion relative to the vehicle 900 may differ at different vehicle speeds, for example due to varying road surface friction, air resistance, or gravitational components (e.g., on a slope). Processing device 120 can determine the acceleration torque by subtracting the road load torque from the requested torque. In some examples, processing device 120 may also subtract the braking torque corresponding to the pedal position of the brake pedal to determine the acceleration torque.

[0065] In some examples, the processing unit 120 is configured to determine the expected acceleration of the vehicle 900 by converting acceleration torque into acceleration. It should be understood how this conversion is performed. In the examples, the acceleration torque is based on... Converted into expected acceleration, where, It is the force corresponding to the accelerating torque. It is the weight of the vehicle, 900, and This is the expected acceleration. Acceleration torque is based on the conversion of tire rolling radius into force. The tire rolling radius and vehicle mass can be pre-configured for vehicle 900, or can be assumed by the control system 110.

[0066] In some examples, processing device 120 is configured to apply one or more limits to the expected acceleration. It should be understood that a “limit” can be a maximum or minimum value, and the expected acceleration is controlled to be no greater than or no less than the “limit”. For example, processing device 120 may determine, receive, or pre-configure a minimum and / or maximum value for the expected acceleration. Processing device 120 may determine the expected acceleration such that the expected acceleration is no greater than or no less than the maximum and / or minimum values, respectively. In some examples, one or more limits on the expected acceleration ensure that at low speeds (e.g., less than 15 kph)—at which anti-rollback features may be activated to prevent vehicle 900 from rolling backwards on a ramp—control system 110 may allow the expected acceleration to increase to zero. (or zero) The above (and not subsequently determined by the difference between expected and actual acceleration) will not affect the control torque output, as this corresponds to the expected vehicle behavior. That is, in some cases, the expected acceleration of the vehicle can be zero when the driver is not pressing the accelerator pedal. However, when a function such as creep is activated, creep can introduce positive torque into the torque output to prevent the vehicle from rolling backward on an uphill slope. In this example, the expected acceleration can be determined taking creep into account to prevent the torque output from decreasing due to the difference between expected and actual acceleration caused by creep, thus preventing the vehicle from rolling backward downhill in the absence of driver input on the pedal. The opposite can be applied at a maximum value to prevent the vehicle from accelerating when stopped on a downhill slope. Meanwhile, at higher vehicle speeds—at which the anti-rollover feature is not expected to activate—one or more limits can have a smaller effect, causing a deviation from the driver's deceleration request to result in a reduction in the torque output of the control torque system 240 controlled by the control system 100. Therefore, one or more limits on the expected acceleration prevent the control system 100 from interfering with the normal operation of other vehicle systems.

[0067] The processing unit 120 is also configured to determine the actual acceleration of vehicle 900 based on vehicle speed. The actual acceleration of vehicle 900 is determined based on vehicle speed signal 162. It should be understood that acceleration is the derivative of speed. In some examples, the actual acceleration of vehicle 900 is determined as the derivative of vehicle speed. That is, the actual acceleration of the vehicle can be determined based on the change of vehicle speed over time. In some examples, the processing unit 120 is configured to filter this derivative, wherein the amount of filtering can be based on the difference between unfiltered acceleration and filtered acceleration. For example, this allows for reduced filtering when a large difference exists, and allows the amount of filtering to differ for increasing acceleration and decreasing deceleration. In the example, the unfiltered acceleration is the derivative of vehicle speed, and the filtered acceleration is the unfiltered acceleration after passing through a filter (in some examples, the filter can be a low-pass filter). The time constant of the low-pass filter can be based on the filtered acceleration minus the unfiltered acceleration at a previous time step.

[0068] The processing device 120 is also configured to compare the expected acceleration of the vehicle 900 with the actual acceleration. In some examples, the processing device 120 is configured to determine the difference between the expected acceleration of the vehicle 900 and the actual acceleration of the vehicle 900.

[0069] The processing device 120 is also configured to generate a torque control signal 170 based on the comparison to control the torque output of the torque system 240. In one example, the processing device 120 is configured to generate the torque control signal 170 to control the torque output of the torque system 240 such that the actual acceleration of the vehicle 900 is controlled to reduce the difference between the expected acceleration of the vehicle 900 and the actual acceleration of the vehicle 900. In another example, the processing device 120 is configured to generate the torque control signal 170 to control the torque output of the torque system 240 such that the actual acceleration of the vehicle 900 is controlled to be equal to the expected acceleration of the vehicle 900. In yet another example, the torque control signal 170 is configured to control the torque system 240 to reduce the positive torque in the torque output of the torque system 240.

[0070] In some examples, if the rotational speeds of multiple wheels of the vehicle vary significantly, the processing unit is configured not to generate torque control signal 170. Alternatively, if the rotational speeds of different wheels vary significantly, the processing unit may set torque control signal 170 to zero. Therefore, the torque output of the torque system is not controlled to reduce the difference between the expected acceleration of vehicle 900 and the actual acceleration of vehicle 900. For example, the rotational speeds of different wheels may differ due to different road conditions at different wheels (e.g., one or two wheels on a small patch of ice on an otherwise dry asphalt road). In some cases, the vehicle's traction control system may cause one or more wheels to be stationary or rotating in the opposite direction to the other wheels of the vehicle. Under any of these conditions, the actual acceleration of the vehicle calculated using the vehicle speed signal may be considered unmeasurable or inaccurate or of insufficient quality. The processing unit may prevent the generation of torque control signal 170 and / or set torque control signal 170 to zero. Such steps may only be taken if the estimated acceleration is within predetermined limits and / or if the estimated speed of the vehicle does not exceed a threshold. For example, if the estimated speed of the vehicle is less than 5 kph (which may occur on some difficult terrain), or less than 10 kph, or less than 15 kph (which can be adapted to some terrain of good overall quality).

[0071] In some examples, processing device 120 is configured to apply one or more limits to the torque output of torque system 240 and generate torque control signal 170 based on said one or more limits. For example, processing device 120 may determine, receive, or pre-configure a minimum and / or maximum value for the torque output of torque system 240. Processing device 120 may generate torque control signal 170 such that the torque output is not greater than or not less than the maximum torque value and / or the minimum torque value, respectively. In examples, the minimum torque output of the torque system may be based on one or more of the following: creep torque associated with the creep function of vehicle 900, the requested torque indicated in torque demand signal 160, and / or zero torque. It should be understood that the requested torque indicated in torque demand signal 160 may correspond to the driver's acceleration demand on a flat road surface and may be unaffected by other vehicle characteristics that may subsequently add or remove torque from the driver's demand. In the example, the creep torque includes a certain amount of torque requested by the creep function of vehicle 900, wherein the creep function requests creep torque to maintain the vehicle creep speed when the requested torque (i.e., the torque requested by the driver using the accelerator pedal and / or brake pedal) is zero. In one example, the creep speed is between 0 kph and 6 kph, but it should be understood that the invention is not limited thereto. Advantageously, the maximum and / or minimum torque output applied when determining the torque control signal 170 ensures compatibility of the invention with other vehicle systems by providing an adaptive target for torque (or acceleration) based on other vehicle system settings. In other words, the torque control signal 170 of the invention can be determined using one or more torque output limits to take into account target torque and / or acceleration associated with other vehicle functions. For example, the maximum and / or minimum torque output can be determined at least in part based on other functions of vehicle 900. For example, control system 100 can determine that the minimum torque output corresponds to the creep function of vehicle 900, wherein the creep function maintains a low vehicle speed without any torque requested by the driver. In this case, the torque control signal of the present invention is prevented from controlling vehicle acceleration to reduce the vehicle speed below the creep speed. It should be understood that the maximum torque output and / or minimum torque output can be determined based on other functions, or a combination of functions.

[0072] In some examples, processing device 120 is configured to generate torque control signal 170 based on one or more of a proportional term and an integral term. Processing device 120 can be configured to add a proportional term to the integral term. The proportional term can indicate the real-time difference between the expected acceleration and the actual acceleration of vehicle 900. The integral term can indicate the difference between the expected acceleration and the actual acceleration of vehicle 900 over time. By taking both the proportional and integral terms into account, control system 100 advantageously corrects the steady-state error of control system 100.

[0073] To determine the proportional term, the processing unit 120 can be configured to multiply the difference between the actual acceleration of the vehicle 900 and the expected acceleration of the vehicle 900 by a first gain factor. In some examples, the first gain factor is implemented as a curve dependent on the current difference between the expected and actual acceleration of the vehicle 900. This allows the first gain factor to increase in the presence of a large difference, resulting in a more drastic response from the control system 100. In some examples, the proportional term is limited between 0 and a negative controller allowable value. This prevents the control system 100 from adding positive torque back into the system, which may be undesirable for the driver of the vehicle 900.

[0074] To determine the integral term, the processing unit 120 can be configured to, for a first time window, multiply the difference between the actual acceleration of vehicle 900 and the expected acceleration of vehicle 900 by a second gain factor and then by the execution rate. The second gain factor may be different from or equivalent to the first gain factor. In this example, the second gain factor is a different curve than the first gain factor. However, it should be understood that the first and second gain factors share the same input: the current difference between the expected and actual acceleration of vehicle 900. This allows the integral term to behave differently for different amounts of difference.

[0075] The processing device 120 can also be configured to determine the integration term based on the integration term of a first time window and the integration term of a second time window preceding the first time window. For example, the processing device 120 can add the integration term of the first time window to the integration term of the second time window. The processing device 120 can also be configured to determine the integration term based on the maximum integration term. The maximum integration term can be determined based on previous integration terms and the integrator execution rate. In some examples, the processing device 120 can also limit the integration term with zero and / or a minimum limit.

[0076] The output device 150 is arranged to output a torque control signal 170 to the torque system 240. The torque control signal 170 is configured to control the torque output of the torque system 240 as described above.

[0077] In some examples, torque control signal 170 can be output to torque system 240 to reduce the torque output of torque system 240. In another example, torque control signal 170 can also control torque system 240 to distribute at least a portion of the requested torque to the brakes of vehicle 900 based on a comparison of the expected acceleration of vehicle 900 with the actual acceleration. Advantageously, this can prevent vehicle 900 from rolling back on a slope when torque is removed from the torque output of torque system 240.

[0078] In some examples, output device 150 and processing device 120 may also be configured to generate a coasting-to-stop control signal based on torque control signal 170. The coasting-to-stop signal is output to a coasting-to-stop controller to control the torque demand of the coasting-to-stop controller. The coasting-to-stop controller is configured to operate the coasting-to-stop function of vehicle 900. The coasting-to-stop function of vehicle 900 may include a function to request positive torque to enable a one-pedal driving mode of vehicle 900. In examples, the coasting-to-stop function may include at least two of the following functions: anti-rollback, to prevent vehicle 900 from rolling backward when vehicle 900 is on an uphill slope; and stopping vehicle 900 when the driver releases the accelerator pedal during a downhill slope. In some examples, the coasting-to-stop controller is logically located at... Figure 1 The control system 100 is upstream of the control system 100. Therefore, the control system 100 can be configured to output a coast to stop signal to correct the output of the coast to stop controller if the coast to stop controller requests excessive positive torque.

[0079] In one example, the proportional and / or integral terms may be determined by one or more of a proportional-integral (PI) controller or a proportional-integral-derivative (PID) controller; however, it should be understood that the invention is not limited thereto, and the control system 100 may include any number and type of suitable controllers. In one example, the processing device 120 includes a PI controller configured to minimize the difference between the actual acceleration of the vehicle 900 and the expected acceleration of the vehicle 900.

[0080] Figure 2A schematic diagram of the components of a vehicle 900, including a torque system 240, is shown. The vehicle 900 includes a control system 100, a powertrain 210, and a basic braking system 220. The control system 100 is arranged to control the powertrain 210 and the basic braking system 220. The vehicle 900 may be a hybrid electric vehicle with an electric motor and an internal combustion engine, both arranged to drive the wheels of the vehicle 900; or it may be a battery electric vehicle powered only by an electric motor; or it may be a vehicle powered only by an internal combustion engine. In some cases, the vehicle 900 may have multiple electric motors arranged to drive the wheels. The vehicle 900 may also be a mild hybrid electric vehicle (MHEV) or a plug-in hybrid electric vehicle (PHEV).

[0081] Vehicle 900 has a control system 100, which includes multiple controllers. The controllers are collectively configured to: receive data from various sensors, systems, and input devices of vehicle 900; process the data; and output commands for controlling vehicle 900. Each controller may individually include, or may collectively include, a processing unit and a memory unit. The processing unit may be one or more electronic processing units operably executing computer-readable instructions. The memory unit may be one or more memory devices. The memory devices are electrically coupled to the processing unit. The memory devices are configured to store instructions, and the processing unit may be configured to access the memory devices and execute the instructions stored thereon. Control system 100 may be… Figure 1 The control system 100.

[0082] The control system 100 is arranged to control the powertrain 210. The powertrain includes a power source 212. The power source 212 may be an electric motor, and in some cases, the powertrain 210 may have two power sources 212, one as an electric motor and the other as an internal combustion engine. In another example, the powertrain 210 may include a single power source 212 as an internal combustion engine. The powertrain 210 also includes a drivetrain 214, which is arranged to: receive torque 215 from the power source 212; convert the torque; and provide the converted torque to the wheels. The drivetrain 214 may be a direct-drive drivetrain, or it may have a gearbox and a differential to increase the torque 215 transmitted from the power source 212, such that a higher torque can be transmitted to the wheels of the vehicle 900. The powertrain 210 can thus output positive torque.

[0083] The powertrain 210 is controlled and monitored by the control system 100. The control system 100 is arranged to output a motor torque demand signal 211 (also referred to as a desired torque signal 211) to the powertrain 210 to cause the power source 212 to generate the desired amount of torque 215. The control system 100 is also arranged to receive data 213 from the powertrain 210, such as the torque generation signal 213. The received data 213 may include the rotational speed of the power source 212 and may include the torque generated by the power source 212. The control system 100 may also receive data 213 related to the transmission system 214 and send commands 211 related to the transmission system 214. The control system 100 may send commands 213 to the powertrain 210, such as a shift command for changing the torque ratio of the transmission system 214. The control system 100 may also receive data 213, which may include the rotational speed of one or more components of the transmission system 214, or the amount of torque received by or output by the transmission system 214. The torque ratio of the transmission system can be sent from the transmission system 214 to the control system 100 as part of the data 213, or it can be stored in the control system 100 as a value, because the control system 100 can command the transmission system 214 to control the torque ratio of the transmission system 214.

[0084] Vehicle 900 also has a basic braking system 220. The basic braking system 220 includes a brake actuator 222 and a basic brake 224. The brake actuator 222, which may be a hydraulic pump or an electromechanical actuator, is used to move components of the basic brake 224, said components being arranged to frictionally engage to provide braking torque (or negative torque). Thus, the brake actuator 222 can apply a force 225 to the basic brake 224. The basic brake 224 can be any friction brake, such as a brake disc with movable calipers or a drum brake with movable brake shoes. By moving the components of the basic brake 224 into engagement, the basic braking system 220 can provide braking torque to the wheels to decelerate the vehicle.

[0085] The term "basic brake" is generally used herein to refer to any friction brake that can decelerate a vehicle by converting mechanical energy into heat through friction, as opposed to a regenerative brake, such as a regenerative brake that can be provided by an electric motor. It should be understood that, in another example, the basic braking system 220 may also include one or more regenerative braking systems.

[0086] The control system 100 is configured to output a braking command signal 221 to the base braking system 220. The braking command signal 221 includes a base brake release signal, which is configured to disengage the base brake actuator 222 from the base brake 224, thereby reducing the braking torque. The braking command signal 221 also includes a brake activation signal, which is configured to engage the brake actuator 222 with the base brake 224, thereby increasing the braking torque applied to the wheels.

[0087] The control system 100 can receive braking data 223 from the base braking system 220. The base braking data 223 may include information about the generated braking torque, which may differ from the commanded braking torque due to hysteresis in the activation of the brake actuator 222. The data 223 may include information that brake release has been achieved, such that negligible braking torque is being provided by the friction brake 224. This signal may also be referred to as a brake release signal.

[0088] The powertrain 210 and the basic braking system 220 can be considered together as the torque system 240, such as Figure 2 As indicated by the dashed lines, the torque system 240 can be configured to output torque 231 to one or more wheels 230 of the vehicle. The output torque 231 can be based on a positive torque associated with the powertrain 210 and a negative torque associated with the basic braking system 220. The output torque 231 is controlled by the control system 100 as described above. Figure 1 As explained, the commands 211 and 221 output by the control system 100 to the power system 210 and the basic braking system 220 can be considered as being determined by... Figure 1 A portion of the torque control signal 170 output by the control system 100.

[0089] Figure 1 The control system 100 can be configured to output a torque control signal 170 to control one or both of the powertrain 210 and the base braking system 220. For example, the torque control signal 170 can be configured to remove positive torque from the torque output of the powertrain 210 and / or distribute torque from the powertrain 210 to the base braking system 220.

[0090] The control system 100 is also configured to receive additional input signals. (As mentioned above...) Figure 1 As illustrated, the control system 100 is arranged to receive a vehicle speed signal 162 and a torque demand signal 160. In some examples, the control system 100 may be configured to receive one or more signals indicating the activation or deactivation of one or more of the following: a crawl function, an adaptive pedal progression function, an off-road function, a one-pedal driving mode, or a coast-to-stop feature.

[0091] The control system 100 may also receive additional inputs from other input devices (not shown). For example, a gear shift lever may provide an input signal for selecting a driving mode, reverse mode, or parking mode. The control system 100 may also receive suspension load data from suspension sensors, which may be strain sensors. The load sensors may provide information about the vehicle's pitch and / or the vehicle's mass and mass distribution. This can be used to determine the vehicle's mass and / or the gradient of the road surface on which the vehicle is located.

[0092] It will be understood that the control system 100 may consist of multiple independent controllers or processors, and signals described as being received or output by the control system may be published on a central CAN bus, or output by one part of a computer program and received by another part of the computer program. Received signals may also be retrieved from internal memory or determined by a program within the control system 100.

[0093] Figure 3 This is a flowchart illustrating a method 300 according to an embodiment of the present invention. Figure 3 Method 300 can be derived from Figure 1 The control system 100 and / or Figure 2 The torque system 240 is executed. Figure 3 Method 300 can be used to generate a torque control system 240 (e.g., Figure 2 A method for the torque output of a torque system 240) using one or more torque control signals.

[0094] Method 300 includes receiving 310 a torque demand signal 160 indicating a requested torque. The torque demand signal 160 may also indicate the position of one or more of the accelerator pedal and / or brake pedal. In some examples, the requested torque corresponds to the position of the accelerator pedal and may also depend on whether a vehicle feature such as an adaptive pedal progressive mode is activated. As explained above, an adaptive pedal progressive mode may be a vehicle function in which the torque request associated with the accelerator pedal position is scaled differently according to one or more factors, such as road surface gradient.

[0095] Method 300 includes receiving a vehicle speed signal 162 indicating the speed of the vehicle at 320. The vehicle speed may be monitored by one or more sensors, which, as will be understood, may include one or more sensors configured to monitor the vehicle's position (e.g., a GPS sensor), the rotational speed of the vehicle's wheels, an accelerometer, or any other suitable sensor.

[0096] Optionally, method 300 includes step 325 ensuring that the quality of the vehicle speed signal is sufficient for its use. If the rotational speeds of different wheels vary significantly, the calculation of the actual vehicle acceleration may be considered insufficiently accurate or unmeasurable. For example, the wheel speed from the first wheel may indicate wheel rotation in a first direction, while the wheel speed from the second wheel indicates wheel rotation in a second direction, which is opposite to the first direction. In this case, method 300 prevents the generation of a torque control signal, and no further step 325 is present in this process. Therefore, when the first direction is opposite to the second direction, the torque control signal 170 is not generated or is set to zero, so that the torque control signal does not control or change the torque output of the torque system.

[0097] Method 300 includes determining the expected acceleration of vehicle 330. The expected acceleration of the vehicle is determined based on the assumption that the vehicle is on a flat road surface. That is, the expected acceleration of the vehicle is determined as if the vehicle were driven on a flat road surface (i.e., there is no gradient factor), and is based on the vehicle speed and the requested torque. In some examples, the expected acceleration of the vehicle is determined by subtracting the road load torque and / or braking torque from the requested torque to determine the acceleration torque. The acceleration torque can then be converted into acceleration based on the vehicle mass and the vehicle tire rolling radius, as shown in the figure. Figure 4 A more detailed explanation follows.

[0098] Method 300 includes determining the actual acceleration of vehicle 340. The actual acceleration of the vehicle is determined based on the vehicle speed indicated by vehicle speed signal 162. The actual acceleration of the vehicle is determined based on the derivative of the vehicle speed. It should be understood that various filters can be applied to the vehicle speed, such as those already applied to… Figure 1 and Figure 2 For example, vehicle speed can be filtered to detect the decrease in vehicle speed corresponding to the driver engaging the vehicle brakes.

[0099] Method 300 includes comparing the expected acceleration of the vehicle determined in 350 with the actual acceleration of the vehicle. In some examples, method 300 includes determining the difference between the expected acceleration and the actual acceleration of the vehicle.

[0100] Method 300 includes generating a torque control signal 170 based on the comparison. For example, the torque control signal 170 may be generated based on a determination that the actual acceleration of the vehicle exceeds the expected acceleration of the vehicle on a flat road surface. The torque control signal 170 is a control signal for controlling the torque output of the torque system, as already described. In some examples, the torque control signal 170 may be generated to control the torque system 240 to reduce the positive torque output by the torque system 240. For example, the torque control signal 170 may be generated to control the torque output of the torque system 240 such that the actual acceleration of the vehicle is reduced to decrease the difference between the actual acceleration of the vehicle and the expected acceleration of the vehicle on a flat road surface.

[0101] It should be understood that it can be omitted. Figure 3 Method 300 may include one or more steps, or may include additional steps not shown. For example, method 300 may be implemented such that the difference between the expected acceleration and the actual acceleration of the vehicle is received, while the determination of the difference, the determination of the expected acceleration, and the determination of the actual acceleration are performed elsewhere and can therefore be omitted. In another example, the actual acceleration of the vehicle may be received directly from the accelerometer, and the step of determining the actual acceleration of vehicle 340 may be omitted. Furthermore, it should be understood that although Figure 3 The method steps are shown in a specific order, but the invention is not limited thereto. For example, the determination of the vehicle's expected acceleration and the vehicle's actual acceleration can be performed in different orders, or they can be performed simultaneously.

[0102] Figure 4 This is a flowchart illustrating a method 400 for determining the expected acceleration of a vehicle on a flat road surface according to an embodiment of the present invention. Figure 4 Method 400 can be derived from Figure 1 The control system 100 and / or Figure 2 The torque system 240 is executed. Figure 4 Method 400 may be used to perform according to embodiments of the present invention. Figure 3 The method 300 is a method for determining the expected acceleration of a vehicle on a flat road surface in step 330.

[0103] Figure 4 Method 400 includes determining 410 a road load torque based on vehicle speed (e.g., the vehicle speed of vehicle speed signal 162). The road load torque is the torque corresponding to the force that impedes the movement of the vehicle at the current vehicle speed. For example, the movement of the vehicle may be impeded by forces including friction and air resistance. The sum of these impeding forces can correspond to the road load torque, which is the torque required to overcome the impeding forces and maintain the vehicle speed. It should be understood that such impeding forces can vary depending on the vehicle speed.

[0104] Method 400 also includes receiving braking torque information at 420. The braking torque information can be received from torque system 240 (e.g., from basic braking system 220) and can indicate a driver's request for braking or negative torque. The driver's request for braking torque can be associated with the position of the brake pedal.

[0105] Method 400 also includes determining the acceleration torque 430. The acceleration torque can be determined by subtracting the road load torque and / or braking torque from the requested torque of the torque demand signal 160. The acceleration torque should be understood as the net torque corresponding to any negative torques in the system after deducting, including but not limited to, road load torque and braking torque. The acceleration torque can also be understood as a certain amount of torque that causes the vehicle 900 to accelerate when output by the torque system 240.

[0106] Method 400 also includes converting the acceleration torque 440 into the vehicle's expected acceleration on a flat road surface. As already explained, this is based on the formula... The process converts acceleration torque into expected acceleration. It should be understood that the conversion of acceleration torque into expected acceleration can be based on vehicle speed, vehicle mass, and tire rolling radius. Vehicle mass and tire rolling radius can be predetermined, received from another vehicle system, or estimated by control system 100.

[0107] Method 400 may also include applying one or more of a maximum or minimum value of 450 to the vehicle's expected acceleration. The maximum and / or minimum values ​​may also be referred to as limiting. In some examples, the maximum or minimum value of the vehicle's expected acceleration may be determined based on the vehicle's speed. In one example, at low speeds, method 400 may allow positive torque to increase the vehicle's acceleration to zero or slightly above zero to prevent the vehicle from rolling backwards on a slope. In this example, at higher speeds, the maximum or minimum value of the vehicle's expected acceleration may be determined to have a reducing effect, such that a deceleration request from the driver is detected as a trigger for removing torque from the torque output of the torque system 240.

[0108] It should be understood that it can be omitted. Figure 4 The method 400 may include one or more steps, or the method 400 may include additional steps besides those shown. Furthermore, Figure 4 Some steps of method 400 may be performed in a different order than that shown.

[0109] Figure 5 This is a flowchart illustrating a method 500 according to an embodiment of the present invention. Figure 5 Method 500 can be derived from Figure 1 The control system 100 and / or Figure 2The torque system 240 is executed. Figure 5 Method 500 can be used to perform according to embodiments of the present invention. Figure 3 The method of generating torque control signal 170 in method 300 is the method of step 360.

[0110] Figure 5 Method 500 includes comparing 510 the actual acceleration of a vehicle with the expected acceleration of the vehicle on a flat road surface. Method step 510 may include determining the difference between the actual acceleration and the expected acceleration of the vehicle on a flat road surface.

[0111] Figure 5 Method 500 further includes determining one or more of a proportional term and an integral term. The proportional term can be determined based on the difference between the vehicle's actual acceleration and its expected acceleration, as well as a first gain factor. Regarding... Figure 6 The determination of the proportional term is explained in more detail. The integral term can be determined based on the difference between the vehicle's actual acceleration and its expected acceleration, the second gain factor, and the actuation rate. The integral term can indicate the difference between the vehicle's actual acceleration and its expected acceleration over time. Regarding... Figure 7 The determination of the integral term will be explained in more detail.

[0112] Figure 5 Method 500 also includes generating a torque control signal 170. The torque control signal 170 can be determined by summing proportional and integral terms. It should be understood that one or more weights can be applied to either or both of the proportional and integral terms before summing. The torque control signal 170 indicates the amount of torque to be removed from the torque output of the torque system 240 based on the difference between the vehicle's actual acceleration and its expected acceleration on a flat road surface, as explained above.

[0113] Figure 5Method 500 may further include outputting a torque control signal 540 to torque system 240 to control the torque output of torque system 240. Method 500 may also include outputting a torque control signal to one or more downstream torque control systems. One or more downstream torque control systems may include any system configured to add torque to or remove torque from the torque output of torque system 240. For example, including but not limited to a coast-to-stop controller. The coast-to-stop controller may be a controller that introduces torque to or removes torque from the torque output of torque system 240 to support a one-pedal driving mode, thereby stopping the vehicle or reaching a predetermined vehicle speed (e.g., on a downhill slope), or preventing the vehicle from rolling backward (e.g., on an uphill slope). Torque control signal 170 may be output to the coast-to-stop controller to prevent the reintroduction of torque removed from the torque output of torque system 240 by the downstream control systems.

[0114] In another example, method 500 may further include an output torque control signal 170 configured to redistribute torque from the torque output of torque system 240 to one or more braking systems, for example... Figure 2 The basic braking system 220. In this example, the redistributed torque can be applied to the vehicle's brakes to prevent the vehicle from rolling down a slope due to the removal of torque from the torque output of the torque system 240.

[0115] It should be understood that it can be omitted. Figure 5 Method 500 may include one or more steps, or may include additional steps besides those shown. For example, method 500 may also include outputting torque control signal 170 to one or more other systems or controllers besides those mentioned above. In some examples, method 500 may also include applying one or more minimum or maximum values ​​corresponding to minimum or maximum torque output to torque control signal 170. In one example, minimum torque output may be determined based on one or more of creep torque associated with creep function, driver-requested torque, and zero torque. (See also: Regarding...) Figure 1As explained, the driver-requested torque can correspond to the driver's needs on a flat road surface, without the influence of any other vehicle functions that might add or remove torque. The creep torque can be the torque associated with a creep function, and the creep function can be a vehicle function that requests torque from the torque system 240 to maintain the vehicle's creep speed. The vehicle creep speed can be a low speed maintained by the creep function (e.g., between 0 kph and 5 kph) without driver input on the accelerator pedal. It should be understood that other maximum or minimum values ​​of the torque output of the torque system 240 can be configured. In one example, the minimum torque output described in the example above can be implemented during the determination of one or more of the proportional or integral terms, as will be explained below.

[0116] Figure 6 This is a flowchart illustrating a method 600 according to an embodiment of the present invention. Figure 6 Method 600 can be derived from Figure 1 The control system 100 and / or Figure 2 The torque system 240 is executed. Figure 6 Method 600 is a method for determining a proportional term, and can be considered as a method for performing according to an embodiment of the present invention. Figure 5 Method 500 is part of step 520 of the method.

[0117] Figure 6 Method 600 includes comparing the expected acceleration of vehicle 610 with the actual acceleration of vehicle 610. Figure 6 Step 610 can be combined with Figure 5 Step 510 is the same. Comparing the vehicle's expected acceleration with its actual acceleration may include determining the difference between the vehicle's expected acceleration and its actual acceleration.

[0118] Method 600 includes determining 620 or receiving a minimum torque authority from control system 100. The minimum torque authority indicates the minimum torque output of torque system 240 according to an embodiment of the invention. As explained above, in one example, the minimum torque authority may correspond to creep torque, driver-requested torque (in some examples, driver-requested torque corresponds to the driver's needs on a flat road surface, and does not originate from sources such as those mentioned above and regarding...). Figure 1 This refers to one or more of the following: (any input to the adaptive characteristics of the adaptive pedal progressive mode or coast to stop function discussed) or zero torque. In one example, the minimum torque limit could be the lowest of these exemplified minimum torques. In another example, the minimum torque limit could be the highest of these exemplified minimum torques. It should be understood that other minimum torque values ​​may be included in addition to those exemplified above.

[0119] Method 600 also includes determining a proportional term 630. The proportional term is determined by multiplying the difference between the vehicle's expected acceleration and its actual acceleration by a first gain factor. In some examples, the first gain factor is implemented as a curve dependent on the current difference between the vehicle's expected and actual acceleration. This allows the first gain factor to increase in the presence of a large difference, resulting in a more drastic response from the control system 100. In some examples, the proportional term is limited between 0 and a negative controller allowable value. This prevents the control system 100 from adding positive torque back into the system, which may be undesirable for the vehicle's driver.

[0120] In some examples, determining the proportional term 630 includes applying one or more of a minimum or maximum limit to the proportional term. In one example, the minimum limit is the minimum torque limit described above. In another example, the maximum limit is predetermined. In yet another example, the maximum limit is 0 Nm so that the proportional term is not allowed to add positive torque to the torque output of the torque system 240.

[0121] Method 600 also includes an output 640 proportional term. It should be understood that the proportional term can be “output” from one part of the control system 100 to another part, or it can be stored in the temporary or permanent memory of the control system 100.

[0122] It should be understood that it can be omitted. Figure 6 The method 600 may include one or more steps, or the method 600 may include additional steps besides those shown.

[0123] Figure 7 This is a flowchart illustrating a method 700 according to an embodiment of the present invention. Figure 7 Method 700 can be derived from Figure 1 The control system 100 and / or Figure 2 The torque system 240 is executed. Figure 7 Method 700 is a method for determining an integral term, and can be considered as a method for performing an integral term according to an embodiment of the present invention. Figure 5 This is part of step 520 of method 500. It should be understood that... Figure 7 Method 700 can be used with Figure 6 Method 600 can be executed sequentially or simultaneously. In another example, the torque control signal 170 can be determined based on either the proportional or integral term alone.

[0124] Figure 7 Method 700 includes comparing 710 the vehicle’s expected acceleration with the vehicle’s actual acceleration. Figure 7 Step 710 can be combined with Figure 5 Step 510 and / or Figure 6The same applies to step 610. It should be understood that the comparison can be performed only once, rather than as... Figure 5 , Figure 6 and Figure 7 Each method is executed as a part, but for completeness, comparisons will be described as part of each method. Comparing the expected acceleration of vehicle 710 with the actual acceleration of vehicle 710 may include determining the difference between the expected acceleration and the actual acceleration of vehicle 710.

[0125] Method 700 includes receiving 720 or determining 720 a minimum torque limit of control system 100. The minimum torque limit can be related to... Figure 6 The minimum torque authority is received or determined in the same manner as described in method 600. The minimum torque authority indicates the minimum torque output of the torque system 240 according to an embodiment of the invention. As explained above, in one example, the minimum torque authority may correspond to one or more of creep torque, driver-requested torque, or zero torque. In one example, the minimum torque authority may be the lowest of these exemplary minimum torques. In another example, the minimum torque authority may be the highest of these exemplary minimum torques. It should be understood that other minimum torque values ​​may be included in addition to those illustrated above.

[0126] In the example, method 700 may also include receiving data based on... Figure 6 The proportional term is determined by method 600. As will be explained, the integral term for a specific time period can be determined by multiplying the difference between the vehicle's expected acceleration and its actual acceleration by a second gain factor and then by the integrator's execution rate. In one example, the second gain factor and the first gain factor are the same, and the integral term can be determined by multiplying the proportional term by the integrator's execution rate. In this example, the second gain factor is a different curve than the first gain factor. However, it should be understood that the first and second gain factors share the same input of the current difference between the vehicle's expected and actual accelerations. This allows the integral term to behave differently for different amounts of difference.

[0127] Method 700 includes determining an integral term for a specific time period 730. The integral term can be determined for a specific time period. The time period can be defined by a multiple of the integrator execution rate. In one example, the integrator execution rate could be 10 ms, but it should be understood that this disclosure is not limited thereto. For a specific time period, the integral term is determined by multiplying the difference between the vehicle's expected acceleration and the vehicle's actual acceleration by a second gain factor and the integrator execution rate.

[0128] In some examples, the integral term is subsequently restricted by one or more of a minimum or maximum value. The minimum and / or maximum value of the integral term can be similar to those described above. Figure 6 The minimum and / or maximum values ​​of the proportional terms are used to determine the value. For example, the minimum value of the integral term may be based at least in part on the minimum torque limit of the control system 100.

[0129] In one example, one or more of the minimum and / or maximum values ​​of the integral term can be determined based on one or more other factors. In another example, the maximum value of the integral term is determined based on one or more control signals indicating a particular vehicle condition. For example, a vehicle condition may include driver input on the brake pedal or a vehicle speed of zero. These vehicle conditions can be considered to prevent the integral term from increasing under certain circumstances.

[0130] In another example, the minimum and / or maximum values ​​of the integral term can be determined based on the integral term for the current time period. For example, the integral term for the first time period can be limited to prevent the integral term for the first time period from increasing beyond the integral term for the second time period preceding the first time period.

[0131] Method 700 also includes adding the integral term for the determined specific time period to the integral term for the previous time period at 740. Advantageously, the integral term can be considered as having a memory of the difference between the expected acceleration of the vehicle and the actual acceleration of the vehicle across time periods. Therefore, the integral term is able to prevent steady-state controller errors. In some examples, the summed integral term may then be limited by one or more additional minimum or maximum values. For example, the summed integral term may be limited by a controller minimum limit (e.g., minimum torque authority) or a zero value. It should be understood that, in this specification, the sum of the integral term for the specific time period and the integral term for the previous time period is referred to as the "integral term".

[0132] Method 700 may also include an output integral term. It should be understood that the integral term may be “output” from one part of the control system 100 to another part, or it may be stored in the temporary or permanent memory of the control system 100.

[0133] It should be understood that it can be omitted. Figure 7 The method 700 may include one or more steps, or the method 700 may include additional steps besides those shown.

[0134] Figure 8 This is a line graph showing a simulation of the torque system 240 according to an embodiment of the present invention. Figure 8 The diagram shows lines representing the following: vehicle output torque 810, vehicle speed 820, actual vehicle acceleration 830, expected vehicle acceleration 840, the difference between actual and expected acceleration 850, and the acceleration determined by a control system, for example... Figure 1The proportional term 860 output by the control system 100, the integral term 870 output by the control system 100, and the sum of the proportional term 860 and the integral term 870, 880. Figure 8 The example illustrates a situation where a positive torque exceeding the torque requested by a driver input (e.g., by pressing the accelerator pedal) is injected into the torque output 810. An example of such a situation is when a vehicle function, such as a coasting-to-stop function, injects positive torque into the output torque 810. Figure 8 In the example, the requested torque (corresponding to the driver's input on the pedal) is constant, indicated by the flat line in the top section.

[0135] If it is possible Figure 8 As seen in the diagram, a significant positive torque was initially introduced into the output torque 810, as evidenced by the sharp increase in the output torque 810. Figure 8 The simulation shows the introduction of positive torque into the output torque 810, but in reality, this might correspond to the vehicle system incorrectly introducing too much torque. Figure 8 In the diagram, we can see that the vehicle speed initially decreases from 820 until it reaches the point where positive torque is introduced into the output torque 810. (This can be seen in...) Figure 8 As seen in the diagram, the vehicle speed 820 increases in response to the increase in output torque 810. This also results in a significant increase in the vehicle's actual acceleration 830, as the vehicle accelerates in response to the introduced torque. The actual acceleration 830 subsequently exceeds the vehicle's expected acceleration 840, resulting in a negative difference 850 between the actual acceleration 830 and the expected acceleration 840. It should be understood that there may be a time delay between the introduction of positive torque into the torque output 810 and the changes in vehicle speed 820 and acceleration 830, and this time delay may vary between different vehicles and at different speeds. Since the torque introduced into the output torque 810 is not requested by the driver, the expected acceleration remains unchanged.

[0136] Figure 8 The proportional term 860 responds quickly to the difference 850 between the actual acceleration 830 and the expected acceleration 840. The vehicle's actual acceleration 830 begins to decrease, and the difference 850 between the actual acceleration 830 and the expected acceleration 840 also decreases. The integral term 870 takes longer than the proportional term 860 to respond to the difference 850 between the actual acceleration 830 and the expected acceleration 840, but it continues to function even after the difference 850 has decreased. Figure 8It should be understood that the present invention provides a robust and efficient method for managing the torque output of a torque system 240, particularly in the following situation: the torque system 240 outputs positive torque in response to a control signal from a vehicle function, the control signal adding a positive torque exceeding the torque explicitly requested by the vehicle driver. In such a case, the present invention outputs a torque control signal 170 to reduce the difference 850 between the actual acceleration 830 and the expected acceleration 840.

[0137] Figure 9 A vehicle 900 according to an embodiment of the present invention is shown. The vehicle 900 may include... Figure 1 The control system 100 and Figure 2 The torque system 240. As shown, vehicle 900 may also include... Figure 2 The powertrain 210 and basic braking system 220. As already stated, the vehicle 900 may be an internal combustion engine vehicle, a mild hybrid electric vehicle, a plug-in hybrid electric vehicle, or a battery electric vehicle.

[0138] It will be understood that various changes and modifications can be made to the invention without departing from the scope of this application.

Claims

1. A control system for controlling the torque output of a vehicle's torque system to control the vehicle's acceleration on a slope, the control system comprising one or more processors configured to: Receive torque demand signals indicating the requested torque; Receive a vehicle speed signal indicating the speed of the vehicle; The expected acceleration of the vehicle is determined based on the torque demand signal and the vehicle speed signal, wherein, The expected acceleration indication is the expected acceleration of the vehicle in response to providing the requested torque to the vehicle when the vehicle is on a flat road surface. The actual acceleration of the vehicle is determined based on the vehicle speed; Compare the vehicle's expected acceleration with its actual acceleration; as well as The torque output of the torque system is controlled based on the comparison output torque control signal.

2. The control system according to claim 1, wherein, The one or more processors are collectively configured to output the torque control signal to control the torque output of the torque system, such that the actual acceleration of the vehicle is controlled to reduce the difference between the expected acceleration of the vehicle and the actual acceleration of the vehicle.

3. The control system according to any of the preceding claims, wherein, The one or more processors are configured together to: It is determined that the actual acceleration of the vehicle exceeds the expected acceleration of the vehicle; as well as Based on this determination, the torque control signal is output to reduce the torque from the torque output of the torque system.

4. The control system according to any of the preceding claims, wherein, The one or more processors are configured together to: Determine the difference between the actual acceleration of the vehicle and the expected acceleration of the vehicle; as well as Based on the fact that the actual acceleration of the vehicle exceeds the expected acceleration of the vehicle, the torque control signal is output to reduce the torque from the torque output of the torque system, wherein the amount of torque to be removed is determined based on the determined difference.

5. The control system according to any of the preceding claims, wherein, The one or more processors are collectively configured to: determine the expected acceleration of the vehicle based on the acceleration torque component, wherein the one or more processors are collectively configured to: The acceleration torque component is determined by subtracting one or more of the road load torque or braking torque from the requested torque of the torque demand signal. Wherein, the road load torque includes a certain amount of torque corresponding to the resistance to the movement of the vehicle; and The road load torque is determined based on the vehicle speed.

6. The control system according to any of the preceding claims, wherein, The vehicle speed signal includes multiple wheel rotation speeds from the respective plurality of vehicle wheels, and the one or more processors are collectively configured to: Determine the rotational speed of the first vehicle wheel along the first direction; Determine the rotational speed of the second vehicle wheel along the second direction; as well as When the first direction is opposite to the second direction, the torque control signal is set to not control the torque output of the torque system.

7. The control system according to any of the preceding claims, wherein, The one or more processors are configured to determine the expected acceleration of the vehicle based on one or more of the expected maximum acceleration and the expected minimum acceleration.

8. The control system according to any of the preceding claims, wherein, The one or more processors are collectively configured to output the torque control signal based on the minimum torque output of the torque system; The minimum torque output of the torque system is based on one or more of the following: The creep torque associated with the creep function of the vehicle; The requested torque; and Zero torque.

9. The control system according to any of the preceding claims, wherein, The one or more processors are collectively configured to generate the torque control signal according to one or more of the following: Based on the comparison between the vehicle's actual acceleration and the vehicle's expected acceleration, and a proportional term determined by a first gain factor; and The integral term is determined based on the comparison between the vehicle's actual acceleration and the vehicle's expected acceleration, the second gain factor, and the integrator execution rate.

10. The control system according to claim 9, wherein, The integral term is also determined based on the maximum integral term and the previous integral term, the previous integral term including the integral term used to perform the integral term determination first; and The maximum integral term is determined based on the previous integral term and the integrator execution rate.

11. The control system according to any of the preceding claims, wherein, The one or more processors are collectively configured to output the torque control signal based on the comparison, so as to redistribute at least a portion of the requested torque to the vehicle's brakes.

12. The control system according to any of the preceding claims, wherein, The one or more processors are configured together to: Generate a coasting-to-stop control signal based on the torque control signal; and The coasting to stop control signal is output to the coasting to stop controller to control the torque demand of the coasting to stop controller.

13. A torque system for a vehicle, the torque system comprising a control system and a powertrain according to any of the preceding claims, the powertrain being configured to generate and output a torque output of the powertrain according to the torque control signal.

14. A vehicle comprising a control system according to any one of claims 1 to 12 or a torque system according to claim 13.

15. A method for controlling the torque output of a vehicle's torque system to control the vehicle's acceleration on a slope, the method comprising: Receive torque demand signals indicating the requested torque; Receive a vehicle speed signal indicating the speed of the vehicle; The expected acceleration of the vehicle is determined based on the torque demand signal and the vehicle speed signal, wherein the expected acceleration indicates the expected acceleration of the vehicle in response to providing the requested torque to the vehicle when the vehicle is on a flat road surface. The actual acceleration of the vehicle is determined based on the vehicle speed; Compare the expected acceleration and the actual acceleration of the vehicle; and The torque output of the torque system is controlled based on the comparison output torque control signal.

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