Control system for vehicle powertrain

Abstract

Aspects of the present disclosure relate to a control scheme for controlling a vehicle in which an upshift of the vehicle is expected and preparation for the upshift has started. A power source of the vehicle is arranged to generate torque as a function of a predicted driver torque demand, as a function of a normalized torque demand and an indicated torque ratio of the transmission after an expected upshift of the transmission.

Description

Technical Field

[0001] This disclosure relates to control systems for vehicle powertrains. Specifically, but not exclusively, this disclosure relates to the control of the powertrain during upshifts in a vehicle. Aspects of the invention relate to control systems, vehicles, and methods. Background Technology

[0002] It is well known that control systems are provided for vehicles, which process driver input to determine what torque the vehicle's power source should produce. However, existing systems may fail to accurately predict future driver demands—resulting in slower vehicle responses and a less than satisfactory driving experience. In particular, poor torque management during transmission upshifts can lead to slower vehicle responses to changing driver demands or reduced vehicle acceleration.

[0003] Furthermore, existing systems may attempt to manage torque during upshifts by increasing engine torque before the upshift occurs, in order to maintain a relatively constant level of torque at the wheels. However, in cases where, for example, upshift preparation has begun but is subsequently cancelled due to changes in driver demand, existing systems may react slowly, resulting in unintended acceleration of the vehicle.

[0004] The upshifting process can also be highly dependent on how the vehicle is controlled. For example, when the vehicle is controlled by the driver with minimal driver assistance, it may be desirable to upshift to maintain acceleration, or more generally, to allow the vehicle to respond quickly to inputs from the driver. However, when using advanced driver assistance systems (ADAS) such as adaptive cruise control, it may be desirable to minimize the impact of upshifts so that the vehicle's behavior is not significantly affected by upshifts, thus reducing the smoothness of the vehicle's movement.

[0005] The purpose of this invention is to address one or more disadvantages associated with the prior art. Summary of the Invention

[0006] The aspects and embodiments of the present invention provide control systems, vehicles, and methods as claimed in the appended claims.

[0007] According to one aspect of the invention, a control system for controlling a powertrain of a vehicle is provided, the powertrain including a power source and a transmission arranged to receive torque from the power source, the transmission including a gearbox and a torque converter, the control system including one or more processors, said one or more processors being collectively configured to: receive a shift signal indicating a anticipated upshift of the gearbox, the shift signal including an indication of the torque ratio of the gearbox after the anticipated upshift; receive a driver torque demand signal including a driver torque demand; receive a torque converter slip signal including a torque converter slip value; receive a predicted input shaft speed signal including a predicted input shaft speed of the gearbox after the anticipated upshift; determine a normalized torque demand based on the torque demand, the torque converter slip value, and the predicted input shaft speed; determine a predicted torque demand based on the normalized torque demand and the torque ratio of the gearbox after the upshift; and output a first output signal requesting the power source to generate torque according to the predicted torque demand.

[0008] In this way, the torque demand after upshifting can be predicted more accurately. This allows for smoother upshifts by predicting the necessary torque, thus maintaining a consistent rate of acceleration or constant torque at the wheels, as required by driving conditions.

[0009] Torque demand can be the driver's torque demand, such as the input of the accelerator pedal, and predicted torque demand can be the predicted driver's torque demand.

[0010] The processors can be configured to receive a road gradient signal indicating the road's slope and determine the normalized torque demand based on that slope. By taking into account variations in road gradient, torque demand can be predicted more accurately, resulting in a smoother driving experience in a wider range of environments.

[0011] The processors can be configured to receive a vehicle speed signal indicating the vehicle's speed and determine a normalized torque demand based on that speed. By taking vehicle speed into account, the prediction of the driver's torque demand can be further improved and made more accurate. For example, vehicle speed may affect air resistance and rolling resistance, thus altering the vehicle's behavior.

[0012] The processors can be configured to receive a maximum torque capability signal indicating the maximum torque capacity of the power source, and to determine a predicted torque demand based on this maximum torque capability. The maximum torque of the power source can be used in the calculation of the predicted torque demand to ensure that the power system is driven with torque within its capability range, thereby preventing power system damage. Furthermore, since power system torque may vary based on operating conditions, providing a variable value rather than a hard-coded value can further reduce the likelihood of power system damage.

[0013] The power source may include an internal combustion engine and an electric motor, and the processor may be configured to output a first output signal to the internal combustion engine to generate torque based on a predicted driver torque demand before the expected upshift of the transmission occurs. In this way, torque can be increased before the upshift, thereby reducing acceleration lag caused by the potential decrease in torque at the wheels during the upshift.

[0014] The processors can be configured to output a second signal before the expected upshift of the transmission occurs, causing the electric motor to generate motor torque based on the predicted driver torque, the motor torque being the opposite of the torque generated by the internal combustion engine. This allows the internal combustion engine to increase torque without causing unwanted acceleration before the upshift. During the upshift, the motor torque can be reduced quickly and reliably, allowing the torque at the wheels to remain essentially constant.

[0015] According to another aspect of the invention, a vehicle is provided that includes the control system described above.

[0016] According to another aspect of the invention, a method for controlling a powertrain of a vehicle is provided, the powertrain including a power source and a transmission system arranged to receive torque from the power source, the transmission system including a gearbox and a torque converter, the method comprising: receiving a shift input signal instructing an upshift in the gearbox, the shift input signal including an indication of the torque ratio of the gearbox after the upshift; receiving a first input signal including a torque demand; receiving a second input signal including a torque converter slip value; receiving a third input signal including a predicted input shaft speed of the gearbox after the upshift; determining a normalized torque demand based at least in part on the torque demand, the torque converter slip value, and the predicted input shaft speed; determining a predicted torque demand based at least in part on the normalized torque demand and the predicted torque ratio of the gearbox after the upshift; and outputting a first output signal instructing the predicted torque demand, the first output signal being arranged to cause the power source to generate torque.

[0017] According to another aspect of the invention, a computer-readable instruction is provided, which, when executed by a computer, is arranged to perform a method of yet another aspect of the invention.

[0018] According to another aspect of the invention, a control system for controlling a powertrain of a vehicle is provided, the powertrain including a power source and a transmission arranged to receive torque from the power source, the transmission including a gearbox, the control system including one or more processors, said one or more processors being collectively configured to: receive a shift signal indicating an expected upshift in the gearbox; receive a predicted torque demand signal, the predicted torque demand signal including information indicating the predicted torque demand after the upshift; receive a current torque demand signal, the current torque demand signal including information indicating the current torque demand; compare the predicted torque demand after the upshift with the current torque demand; and output a first output signal, the first output signal being arranged to cause the torque generated by the power source to vary according to the comparison.

[0019] In this way, the control system can output a torque modulation value based on the desired torque change relative to the current torque. By outputting a difference rather than an absolute torque value, the downstream process can more easily manipulate the output.

[0020] The predicted torque demand signal can be the first output signal of the first aspect mentioned in the invention. Therefore, the predicted upshift torque demand can be determined using a method according to another aspect of the invention. Other alternative aspects of the first aspect mentioned in the invention can also be incorporated into other aspects of the invention.

[0021] The processors can be configured to apply a modulation factor to the determined difference to calculate a modulated determined difference, and to output a first output signal based on the modulated determined difference. In this way, the determined difference can be changed based on factors such as the source of torque demand or driving mode, allowing torque changes during gear shifts to be modified as needed.

[0022] The processors can be configured to: receive a torque demand signal indicating torque demand; determine a filtered torque demand based on the torque demand signal; and determine a modulation factor based on a comparison between the torque demand signal and the filtered torque demand. Optionally, the torque demand can be a driver torque demand, such as from the accelerator pedal. The filtered torque can be determined based on a low-pass filter. In this case, the deviation between the torque demand (i.e., the original, unfiltered torque demand) and the filtered torque demand can indicate a change in system or driver behavior. Such a change in behavior may require a reduction in deceleration or acceleration. In this case, the torque modulation can be changed accordingly so that the vehicle can quickly meet the driver's demand during upshifts. While the determination of the high-frequency components of the demand can be achieved using a high-pass filter without requiring a comparison step, a low-pass filtering step can be used to provide input to the power source to determine the drive to be generated by the engine, and therefore the introduction of a comparison step can reduce the overall computational requirements.

[0023] The modulation factor can be between 0 and 1. Within this range, the modulation factor can, for example, cancel the torque increase for upshifting when it might be canceled due to a lack of torque demand, or it can maintain the torque increase when the torque demand is similar to the predicted torque demand.

[0024] Applying the modulation factor to the determined difference can include multiplying the determined difference by the modulation factor. This provides an efficient means of applying the modulation factor with low computational requirements.

[0025] The torque demand signal may include information indicating at least one of the following: accelerator pedal input; road gradient; vehicle speed; and driving mode, and one or more processors may be collectively configured to determine the predicted upshift torque demand based on any one of: accelerator pedal input; road gradient; vehicle speed; and / or driving mode. By taking into account factors such as accelerator pedal input, road gradient, vehicle speed, and driving mode, the control system can modify the torque generated by the power source to suit specific driving conditions and driver needs. Therefore, the driving experience can be smoother for the vehicle's occupants.

[0026] According to another aspect of the present invention, a vehicle is provided that includes the control system described above.

[0027] According to another aspect of the present invention, a method for controlling a powertrain of a vehicle is provided, the powertrain including a power source and a transmission system arranged to receive torque from the power source, the transmission system including a gearbox, the method comprising: receiving a shift signal instructing the gearbox to upshift; receiving a predicted torque demand signal, the predicted torque demand signal including information instructing a predicted torque demand after upshift; receiving a current torque demand signal, the current torque demand signal including information instructing a current torque demand; determining a difference between the predicted torque demand after upshift and the current torque demand based on the predicted torque demand and the current torque demand; and outputting a first output signal based on the determined difference and the shift signal, the first output signal being arranged to cause a change in torque generated by the power source.

[0028] According to another aspect of the invention, a computer-readable instruction is provided, which, when executed by a computer, is arranged to perform the method according to the above aspect.

[0029] According to an additional aspect of the invention, a control system for controlling a power source of a vehicle is provided, the control system comprising one or more processors configured to: receive a torque demand signal, the torque demand signal including a torque demand; receive a torque demand source signal, the torque demand source signal (or torque demand signal) including an indication of the source of the torque demand; select a torque modulation scheme based on the source of the torque demand for modulating the torque from the power source during upshifting, so as to modulate the torque from the power source during upshifting; and output a first output signal arranged to cause the power source to change its torque output according to the selected torque modulation scheme.

[0030] In this way, torque modulation can be adjusted based on the source of the torque demand. For example, if the torque demand is received from an advanced driver assistance system (ADAS) such as cruise control, it may be necessary to maintain a substantially constant torque at the output of the drivetrain to make the vehicle move more smoothly. However, if the source of the torque demand is driver input, such as from the accelerator pedal, it may be necessary to make the vehicle more responsive, for example, by adapting to changes in road gradient.

[0031] The processors can be configured to receive a shift signal indicating an expected upshift from the transmission, and to select a torque modulation scheme in response to receiving the shift signal. The torque modulation scheme can be used to manage the torque from the power source during upshifts in the transmission.

[0032] The processors can be configured to determine torque modulation based on torque demand using a selected torque modulation scheme, and the first output signal can be arranged to cause the power source to change its torque output according to the determined torque modulation.

[0033] The processors can be configured to select a first torque modulation scheme when the torque demand originates from an Advanced Driver Assistance System (ADAS) or an autonomous driving system, to maintain a constant torque output from the powertrain during upshifts. In this way, the driver's perception of upshifts can be reduced when using ADAS. Therefore, the driver can enjoy an improved driving experience.

[0034] The shift signal may include an indication of the transmission torque ratio after upshifting, and the first torque modulation scheme may include determining the product of the torque demand before upshifting and the transmission torque ratio, and determining the required torque based on dividing the determined torque demand and torque ratio product by the transmission torque ratio after upshifting. In this way, the torque at the vehicle's wheels can be kept substantially constant while maintaining low computational requirements.

[0035] The processors can be collectively configured to select a second torque modulation scheme to predict the driver's torque demand after upshifting when the source of the torque demand is driver input. The second torque modulation scheme may include the method described in conjunction with the first aspect of the invention for predicting the driver's torque demand. Because the input from the driver may vary compared to an advanced driver assistance system, the system's response may differ. For example, when the driver provides a torque demand input, the torque may be determined based on the driving mode or road gradient, allowing the vehicle to respond to the driver's demand.

[0036] The torque demand signal may include information indicating at least one of the following: accelerator pedal input; road gradient; vehicle speed; and driving mode, and the processor may be configured to predict the driver's torque demand after upshifting based on the first input signal. By taking into account factors such as accelerator pedal input, road gradient, vehicle speed, and driving mode, the control system can modify the torque generated by the power source to adapt to specific driving conditions and driver demands. Therefore, the driving experience can be smoother for the vehicle's occupants.

[0037] According to another aspect of the invention, a vehicle is provided that includes a control system of the additional aspect.

[0038] According to another aspect of the invention, a method for controlling a power source of a vehicle is provided, the method comprising: receiving a shift signal instructing a transmission to upshift; receiving a torque demand signal (or a first input signal) including a torque demand; receiving a torque demand source signal (or a second input signal) including an indication of the source of the torque demand; in response to receiving the shift signal, selecting a torque modulation scheme based on the source of the torque demand to modulate torque from the power source during upshift; and outputting a first output signal causing the power source to change its torque output according to the selected torque modulation scheme.

[0039] According to another aspect of the invention, a computer-readable instruction is provided, which, when executed by a computer, is arranged to perform the method according to yet another additional aspect described above.

[0040] The aforementioned control system may include one or more controllers, which collectively include: at least one electronic processor having an electrical input terminal for receiving input signals; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon to perform a defined method.

[0041] It should be understood that a separately described method can be executed by a common control system, and a separately described control system can actually be a combined common control system. Furthermore, when a signal is described as being received by a control system, the signal can be generated within the control system, for example, through an internal process, and can be received by a part of the control system, such as a downstream process.

[0042] Within the scope of this application, it is expressly intended that various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, claims, and / or 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 subordinate to any other claim and / or incorporated into any other claim, although not initially claimed in this manner. Attached Figure Description

[0043] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0044] Figure 1 A vehicle according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic diagram of the control system and powertrain of a vehicle according to an embodiment of the present invention is shown;

[0046] Figure 3 A flowchart of a method according to an embodiment of the present invention is shown;

[0047] Figure 4 A flowchart of a method according to an embodiment of the present invention is shown;

[0048] Figure 5a , Figure 5b and Figure 5c A graph showing the changes in the powertrain during upshifts;

[0049] Figure 6 A flowchart of a method according to an embodiment of the present invention is shown;

[0050] Figure 7 A flowchart of a method according to an embodiment of the present invention is shown; and

[0051] Figure 8 A flowchart of a method according to an embodiment of the present invention is shown. Detailed Implementation

[0052] Embodiments of the present invention relate to a control system for determining the required torque during a vehicle upshift. Upshifting refers to engaging the transmission to change the gear driven by the vehicle's power source, selecting a "higher" gear and resulting in a lower gear ratio in the vehicle's drivetrain. Typically, if the torque does not change during an upshift, the torque at the vehicle's wheels will decrease. During vehicle acceleration, the driver may feel a decrease in vehicle acceleration.

[0053] Figure 1 Vehicles according to all embodiments of the present invention are shown to provide background for the invention.

[0054] Vehicle 10 includes a control system 100 and a powertrain 111. The control system 100 is arranged to control the powertrain 111. Vehicle 10 can be a hybrid electric vehicle with an electric motor and an internal combustion engine. Vehicle 10 can be a mild hybrid electric vehicle (MHEV). An MHEV may be characterized by not having the ability to charge its battery using mains power and can only charge the battery via the internal combustion engine and regenerative braking. Alternatively, the sole primary energy source for an MHEV may be a liquid fuel, such as gasoline or diesel, and the MHEV may not have an electrical connection for charging the battery from an external source. The battery capacity of an MHEV may be less than 2 kWh. The battery voltage of an MHEV may be approximately 48 volts or lower.

[0055] Alternatively, vehicle 10 may be a plug-in hybrid electric vehicle (PHEV). A PHEV is characterized by being arranged to receive electrical energy from an external source, such as via a connection to mains power. Therefore, a PHEV may include an external electrical connection for charging the battery.

[0056] Figure 2 A schematic diagram of the control system 100 and power system 111 of vehicle 10 is shown.

[0057] Control system 100 is arranged to control the powertrain 111 of the vehicle. The term "powertrain" is intended to encompass a system comprising one or more power sources and a transmission coupled to one or more power sources. Powertrain 111 includes an internal combustion engine 110, an electric motor 120, and a battery 130. In this example, battery 130 is arranged to supply electrical energy 137 to and receive electrical energy 137 from electric motor 120. Internal combustion engine 110 and electric motor 120 may be collectively referred to as a single power source or two power sources. Both internal combustion engine 110 and electric motor 120 transmit torques 117, 127 to transmission 140 of powertrain 111. Transmission 140 includes a gearbox and may include other components such as a torque distributor, torque converter, differential, and wheels of vehicle 10. Other components may be part of transmission 140 other than the gearbox, or the gearbox may be separate from transmission 140.

[0058] It will be understood that this represents only one possible vehicle architecture according to an embodiment of the invention, and other vehicle architectures are also within the scope of the invention, such as architectures with separate electric motors and generators.

[0059] like Figure 2 The control system 100 shown includes a controller, but it should be understood that this is merely illustrative and any number of controllers may be included. The control system 100 includes one or more processors configured collectively to control the powertrain of a vehicle, as described below. The controller includes a processing unit and a memory unit. The processing unit may be one or more electronic processing devices operably executing computer-readable instructions. The memory unit may be one or more storage devices. The memory unit is electrically coupled to the processing unit. The memory unit is configured to store instructions, and the processing unit is configured to access the memory unit and execute the instructions stored thereon.

[0060] like Figure 2 As shown, the control system 100 can provide signals 115, 125 to the internal combustion engine 110 and / or the electric motor 120 to transmit a certain amount of torque. For example, the control system 100 can output signals to the powertrain control module (PCM). In the case of the internal combustion engine 110, signal 115 can be sent to the PCM to advance or delay ignition timing, or to increase or decrease the flow rate of the fuel / air mixture entering the engine 110. Signals can be output by posting on an onboard network (e.g., CAN or FlexRay bus) and received or input by reading the posted information.

[0061] The battery 130 can supply electrical energy 137 to the motor 120 to generate torque, and can also supply electrical energy 139 to electric vehicle components such as heaters, fans, displays, etc. The battery can provide the control system 100 with information about the power 139 supplied to other electrical devices 150.

[0062] The control system 100 may receive information 135 from the battery 130. Examples include one or more of the following: battery charge status; battery temperature; and indications of battery health status. Generally, the information 135 received from the battery may indicate to the control system 100 the battery discharge capacity, which is the rate at which the battery can supply energy to the motor 120 and other electrical devices 150 of the vehicle 10. In some examples, the battery 130 or its battery controller may directly output the battery discharge capacity to the control system 100. The battery 130 or its battery controller may output information 135 to the control system 100 indicating the amount of power supplied to the electrical devices 150.

[0063] The control system 100 includes input devices and output devices. The input devices may include electrical input terminals of the control system 100 adapted to read signals from an on-board network. The output devices may include electrical output terminals of the controller 100 adapted to publish signals on the on-board network. The output devices may be arranged to output a signal 115 for controlling the engine 110, for example, by increasing or decreasing the torque output of the engine. The output devices may be arranged to output a signal 125 for controlling the motor 120, for example, by increasing or decreasing the torque output of the motor.

[0064] The control system 100 is arranged to receive torque demand data 102 from a torque demand input device 101 (e.g., an accelerator pedal). The control system 100 can then determine, at least in part, the required torque to be generated by the engine 110 and the electric motor 120 based on the received torque demand data 102. The control system 110 can then output control signals 115, 125 to control the engine 110 and the electric motor 120 to generate the required torque. The torque demand data 102 may be referred to as the torque demand, or, in an embodiment where the vehicle is manually controlled by the driver, as the driver torque demand. The torque demand data may be the current torque demand. A first input signal may include the torque demand data 102. The current torque demand signal may contain information indicating the current torque demand.

[0065] The control system 100 is arranged to receive a driving mode signal 104 from a driving mode selector 103, which may be in the form of a driving mode selector switch or may be obtained from a touchscreen or other such input from the vehicle's human-machine interface. The driver can select a driving mode based on the desired behavior of the vehicle. For example, a "Sport" mode can be selected when a quick response and high acceleration to the driver's input is desired, while a "Comfort" mode can be selected when a less responsive driving mode is needed. The control system 100 can determine the required torque based at least in part on the driving mode signal 104.

[0066] The control system 100 is arranged to receive a vehicle condition signal 106 from a vehicle condition sensor 105. The vehicle condition sensor 105 may determine attributes such as road gradient and / or vehicle speed, and the vehicle condition signal 106 may include this information. The control system 100 may receive the vehicle condition signal 106 and may determine the required torque based at least in part on the information in the vehicle condition signal (e.g., road gradient and / or vehicle speed). Those skilled in the art will understand that the vehicle condition information signal may include any parameters that directly or indirectly affect the torque requirements of the engine.

[0067] The control system is configured to receive transmission data 108 from a transmission management system 107. The transmission management system 107 may be referred to as a transmission control system or transmission management system. The transmission control system 107 can provide the transmission data 108, and the transmission data 108 may include information such as the target gear after upshifting, a shift signal indicating an impending upshift, a torque converter slip value indicating the degree of slip from the torque converter of the transmission 140, and a predicted transmission input shaft speed after upshifting. A first input signal may include the driver's torque demand. The torque converter slip value signal may include the torque converter slip value. The predicted input shaft speed signal may include the predicted transmission input shaft speed after the expected upshift in the transmission. In some examples, these values ​​may be normalized values.

[0068] The control system 100 may have one or more internally stored values, such as the gear ratios of different gears, the maximum torque capacity of the powertrain, the mixing ratio for changing the torque output of the transmission system 140, and a loss value indicating torque loss in the powertrain. The maximum torque capacity of the powertrain may be referred to as the maximum torque capacity of the power source and may be in the form of a maximum torque capacity signal of the power source.

[0069] The control system 100 can determine the driver torque in the predicted target gear based on any or all of the aforementioned data, and thus can more effectively determine the desired torque in the predicted target gear. Furthermore, the data included in the individual signals 102, 104, 106, and 108 can be combined by the signal management system and received by the control system 100 as a single signal.

[0070] The term "control system" can be used to describe a specific control module or a system of sensors and modules. For example, the drivetrain control module 107, torque demand input device 101, driving mode selection device 103, and vehicle condition sensor 105 can be considered to be within the same control system as control system 100. When a control system is described as being arranged to receive signals, it will be understood that one part or program of control system 100 can receive signals from another part or program of the control system, and the signals do not necessarily have to be sent from external devices to a physically separate control system.

[0071] Figure 3 This is a flowchart illustrating a method 200 for determining the required torque during upshifting.

[0072] In method 200, at step 210, the control system receives a shift signal, for example, from a transmission control module. The shift signal may include an indication of the torque ratio of the current gear and / or the torque ratio of the target gear to which the system is changing (referred to as the upshift torque ratio). The shift signal may indicate the transmission's intended upshift.

[0073] At step 220, the required torque in the target gear is determined, also known as the upshift torque demand. The upshift torque demand can be determined based on any signal received by the control system, as referenced above. Figure 2 Specifically, at step 220, a normalized torque demand can be determined based on the driver's torque demand, the torque converter slip value, and the predicted input shaft speed. The upshift torque demand can be included in a signal such as a predicted torque demand signal. The predicted torque demand signal can contain information indicating the predicted upshift torque demand.

[0074] At step 230, the normalized torque demand can be processed using the transmission torque ratio after upshifting to the target gear (also known as the upshift torque ratio). Therefore, at step 230, the predicted upshift torque demand can be determined. The determination of the upshift torque demand will refer to the following... Figure 4 To elaborate further, the driver's torque demand can be predicted based on the normalized torque demand and the shift signal.

[0075] At step 240, the control system may output a first output signal to cause the power source to generate torque based on the predicted torque demand of the driver.

[0076] In this way, the torque generated by the engine and / or electric motor can be better adapted to the driver's needs, thereby improving the driving experience.

[0077] Figure 4 Another flowchart illustrates how data received by the control system can be processed to determine the predicted driver torque after upshifting. A first processing step 310 may receive inputs from various sources. Specifically, process 310 may receive one or more of the following: accelerator pedal input 301, previous driver or terrain mode 302, current driver or terrain mode 303, road gradient 304, vehicle speed 305, high or low range requirement 307, target gear ratio (excluding torque converter slip) 308, and transmission input shaft speed in the predicted target gear 309. Inputs 301 to 309 may take the form of signals such as road gradient signals, vehicle speed signals, or high or low range requirement signals. Based on inputs 301 to 309, process 310 generates a normalized torque demand 315. Process 310 may include an algorithm for calculating the normalized torque demand 315 based on inputs 301 to 309, the algorithm being selected based on the vehicle's desired characteristics. A second process 320 calculates the predicted torque demand in the target gear based on the normalized torque demand 315. The second process calculates the predicted torque demand 330 in the target gear based on the known losses 321 in the powertrain, the gear ratio 322 in the target gear, and the maximum torque capacity 323 of the powertrain.

[0078] By following process 300, the torque demand in the target gear can be determined more accurately.

[0079] Figure 5a The diagram shows the torque ratio 350 of the transmission versus time during an upshift. The control system receives a shift signal indicating a possible upshift at the first time point T1. At this point, the vehicle's total torque remains constant, and the gear ratio 350 remains unchanged. However, the control system then enters the preparation phase PP.

[0080] like Figure 5b As shown, during the preparation phase, the engine torque increases by 360. This increase helps to address the upcoming gear ratio change during the subsequent ratio phase RP. Furthermore, as... Figure 5c As shown, the motor torque 370 can be reduced during the preparation phase. This reduction in motor torque 370 can be equal to the increase in engine torque 360, ensuring that the total torque remains unaffected.

[0081] Once the engine torque of 360 is increased sufficiently... The control system can then leave the preparation stage (PP) and enter the ratio stage (RP). Torque The increase can be called torque modulation because it is a change in torque, which can be applied to the base torque demand to alter the base torque demand. value. The value is designed to match the increase in torque required during upshifts due to the decrease in torque ratio during the subsequent ratio phase RP.

[0082] During the ratio phase RP, the transmission's torque ratio 350 changes from the first gear torque ratio to the second gear torque ratio. As the clutch disengages from first gear, the torque ratio can gradually change over time as the clutch can be applied to second gear. Therefore, during the ratio phase RP, the transmission can have an effective torque ratio between the first gear torque ratio and the second gear torque ratio.

[0083] During the ratio phase RP, the engine torque 360 ​​can remain constant, while the motor torque 370 can increase. The increase in motor torque 370 and the decrease in torque ratio 350 can be managed so that the product of motor torque 370 and torque ratio 350 remains essentially constant. At the end of the ratio phase, motor torque 370 can be restored to the same value as before the preparation phase PP.

[0084] The total torque, calculated as the sum of engine torque 360 ​​and motor torque 370, can be managed so that the product of the total torque and torque ratio 350 before the preparation phase PP is the same as the product of the total torque and torque ratio 350 after the ratio phase RP.

[0085] Figure 6 A flowchart 400 for determining torque modulation is shown. At step 410, the control system receives a shift input signal from the transmission management system, indicating that a shift is imminent. However, it will be understood that the control system can determine that a shift is to occur and can command the transmission management system 107 to perform the shift. In this case, the shift signal can be an internal signal, such as a signal published on the CAN bus, and can be received in this manner.

[0086] At step 420, the predicted torque demand after upshifting is determined. This can be done by combining the above... Figure 2 The method described in Figure 5 can be used to determine the torque, or alternatively, the required torque can be determined by multiplying the current torque by the torque ratio of the target gear and dividing that value by the torque ratio of the current gear.

[0087] At step 430, the difference between the current torque demand and the predicted torque demand after upshifting is determined. This value can be referred to as torque modulation.

[0088] In step 440, it is determined whether an upshift is likely to continue. If the upshift may be cancelled, a first torque modulation arbitration value can be output, and if the shift is likely to proceed as expected, a second torque modulation arbitration value can be output. If the shift is likely to be completely cancelled and the vehicle should travel in the initial gear, the first torque modulation arbitration value can be 0. If the shift proceeds completely as expected, a torque modulation arbitration value of 1 can be output. Based on any intermediate determinations, a value between 0 and 1 can be output. The torque modulation arbitration value can be considered as the proportion of the torque modulation value that should be passed to the downstream control logic.

[0089] The decision to cancel an upshift can be made by the control system or the drivetrain management system, with signals sent from the decision-making part of the system to other parts. The control system can predict the drivetrain management system's decision to cancel an upshift by comparing filtered torque demand with unfiltered torque demand.

[0090] The determination of whether an upshift will be cancelled can be based on a comparison between the unfiltered torque demand and the filtered torque demand, or a comparison between the predicted torque demand and the actual torque demand. A difference between the actual torque demand or the unfiltered torque demand and the predicted torque demand or the filtered torque demand exceeding a threshold can indicate that acceleration will stop, and optionally, the shift may be cancelled. In the case that acceleration will stop, a torque modulation arbitration value of 0 can be output.

[0091] At step 450, the final torque modulation value can be determined based on the torque modulation value determined at step 430 and the torque modulation arbitration value determined at step 440. The determination of the final torque modulation value at step 450 can be performed by multiplying the torque modulation value by the torque modulation arbitration value.

[0092] At step 460, the final torque value can be determined and output. In some embodiments, the final torque value is output as a first output signal. The final torque value can be a final torque modulation value, which can be arranged to change the torque generated by the power source, or the final torque modulation value can be added to the current torque value to provide the torque requirement. At step 460, the first output signal can be output, which can be arranged to cause the torque generated by the power source to vary based on the difference between the determined predicted upshift torque requirement and the current torque requirement, as well as the shift signal.

[0093] It should be understood that processing steps 450 and 440 can vary, and the torque modulation value can be arbitrated by any method, but processing step 450 can be simplified by providing the torque modulation value.

[0094] Figure 7A flowchart of a method 500 for selecting a torque modulation scheme is shown. At step 510, a shift signal is received, indicating that an upshift of the vehicle's transmission may occur.

[0095] At step 520, the source of the vehicle's torque demand is determined. The torque demand may originate from the driver, for example via the accelerator pedal, or via an advanced driver assistance system (ADAS), such as cruise control or adaptive cruise control. Alternatively, the source of the torque demand may originate from a fully automated driving program or system. This determination may be based on a signal received from the torque demand input device 101 (torque source signal), or it may be determined within the control system, as the control system may continuously communicate with or include an advanced driver assistance system or autonomous driving program. The determined source of the vehicle's torque demand may be output as the torque source signal.

[0096] At step 530, a torque modulation scheme can be selected based on the source of the torque demand. If the source of the torque demand is driver input, the method can move to step 540, and the predicted torque demand in the target gear can be determined using a first torque modulation scheme. The first torque modulation scheme may include a combination of... Figure 3 and Figure 4 The method described is for predicting the driver's torque demand after upshifting.

[0097] If it is determined at step 530 that the source of the torque demand is an advanced driver assistance system, a second torque modulation scheme can be used at step 550. The second torque modulation scheme can be arranged to maintain a substantially constant torque at the vehicle's wheels during upshifts by changing the total vehicle torque so that the product of the torque generated by the power source and the transmission ratio remains substantially constant throughout the shift process. Specifically, torque modulation scheme 550 can determine the torque from the power source such that the product of the power source torque and torque ratio before upshifting is the same as the product of the power source torque and torque ratio after upshifting.

[0098] At step 560, torque modulation can be further processed, for example, using a combination Figure 6 The described torque modulation arbitration scheme may allow the torque modulation output to the power source to generate the necessary torque. The torque modulation can be output as a first output signal. This first output signal can be configured to cause the power source to change its torque output according to the selected torque modulation scheme.

[0099] Figure 8Another flowchart of method 600 is shown, by which a torque modulation value can be determined. Signal 601 is a torque demand source signal indicating the source of the torque demand. At step 610, a torque modulation scheme is determined based on the source of the torque demand. If the torque demand is a driver torque demand input using a driver torque input device (e.g., accelerator pedal), a first torque modulation scheme 620 will be used.

[0100] For use in the first torque modulation scheme 620, the driver's demand in the predicted target gear can be determined, which can also be referred to as the predicted upshift torque demand. The predicted upshift torque demand 621 can be referred to as previously... Figure 3 and Figure 4 The current driver demand 623 can be used in the torque modulation calculation, which may include subtracting the predicted upshift torque demand from the current torque demand to produce a torque modulation value 625.

[0101] Alternatively, if the advanced driver assistance system (ADAS) is the source of the torque demand, a second torque modulation scheme 630 can be used. The second torque modulation scheme 630 may have inputs from the ADAS's primary torque request 631 and the upshift gear ratio 633. To maintain a substantially constant torque at the wheels throughout the upshift, the torque modulation can be calculated by multiplying the primary torque request 631 by the current gear ratio 633, dividing that value by the upshift gear ratio, and then subtracting the primary torque request 631. This produces a second torque modulation value 625.

[0102] The torque modulation value 625 can be received by the torque modulation arbitration process 650 and arbitrated using the torque modulation arbitration value 645.

[0103] The torque modulation arbitration value 645 can be determined at process 640 based on the predicted torque demand 641 and the current torque demand 643. Alternatively, the filtered torque demand 641 and the original, unfiltered torque demand 643 can be used for torque modulation arbitration calculation 640. For example, if the filtered torque demand 641 (which can be based on the original torque demand and processed using a low-pass filter) differs significantly from the original, unfiltered torque demand 643, this can indicate a need to reduce acceleration, a need to cancel upshifting, and therefore the torque modulation arbitration value 645 can be set to 0.

[0104] Therefore, the torque modulation value 655 can be output as the output of the torque modulation process 600.

[0105] It should be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

Claims

1. A control system for controlling a powertrain of a vehicle, the powertrain including a power source and a transmission arranged to receive torque from the power source, the transmission including a gearbox and a torque converter, the control system including one or more processors, the one or more processors being collectively configured to: Receive a shift signal indicating a anticipated upshift of the transmission, the shift signal including an indication of the torque ratio of the transmission after the anticipated upshift; Receive a driver torque demand signal, wherein the driver torque demand signal includes the driver torque demand; Receive torque converter slip value signal, wherein the torque converter slip value signal includes torque converter slip value; Receive a predicted input shaft speed signal, the predicted input shaft speed signal including the predicted input shaft speed of the transmission after the expected upshift of the transmission; The normalized torque demand is determined based on the driver's torque demand, the torque converter slip value, and the predicted input shaft speed. The predicted driver torque demand is determined based on the normalized torque demand and the torque ratio of the transmission after the upshift; and A first output signal is output, which requests the power source to generate torque based on the predicted driver torque demand.

2. The control system according to claim 1, wherein, The processors are collectively configured to: Receive road slope signal indicating road gradient; and The normalized torque requirement is determined based on the road gradient.

3. The control system according to claim 1 or 2, wherein, The processors are collectively configured to: Receive vehicle speed signals indicating vehicle speed; and The normalized torque requirement is determined based on the vehicle speed.

4. The control system according to any of the preceding claims, wherein, The processors are collectively configured to: Receives a signal indicating the maximum torque capability of the power source; and The predicted torque requirement is determined based on the maximum torque capability of the power source.

5. The control system according to any of the preceding claims, wherein, The power source includes an internal combustion engine and an electric motor, and The processors are collectively configured to output the first output signal before the expected upshift of the transmission occurs, so that the internal combustion engine generates the torque based on the predicted driver torque demand.

6. The control system according to claim 5, wherein, The processors are collectively configured to output a second signal prior to the expected upshift of the transmission, causing the motor to generate motor torque based on the predicted driver torque, the motor torque being opposite to the torque generated by the internal combustion engine.

7. A vehicle comprising the control system described in any of the preceding claims.

8. A method for controlling a vehicle's drive system, the method comprising: Receive a shift input signal instructing the transmission to upshift, the shift input signal including an indication of the torque ratio of the transmission after the expected upshift; Receive a driver torque demand signal, wherein the driver torque demand signal includes the driver torque demand; Receive torque converter slip value signal, wherein the torque converter slip value signal includes torque converter slip value; Receive a predicted input shaft speed signal, the predicted input shaft speed signal including the predicted input shaft speed of the transmission after the expected upshift of the transmission; The normalized torque demand is determined based on the driver's torque demand, the torque converter slip value, and the predicted input shaft speed. The predicted driver torque demand is determined based on the normalized torque demand and the indicated torque ratio of the transmission after the expected upshift of the transmission. as well as A first output signal is output, which is configured to cause the vehicle's power source to generate torque based on the predicted driver torque demand.

9. A computer-readable instruction, which, when executed by a computer, is arranged to perform the method according to claim 8.

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