Control system for vehicle powertrain

Abstract

Aspects of the present disclosure relate to a control scheme for controlling a vehicle in which the vehicle is expected to upshift and has begun preparation for upshift. Upshift preparation may be interrupted or canceled with reduced torque demand on the vehicle, thereby improving vehicle responsiveness.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to control systems for vehicle powertrains. In particular, but not exclusively, the present disclosure relates to control of a powertrain during upshifts of a vehicle. Aspects of the invention relate to control systems, vehicles and methods. BACKGROUND

[0002] It is known to provide control systems for vehicles which process driver inputs to determine what torque the power source of the vehicle should produce. Furthermore, existing systems can attempt to manage torque during upshifts by increasing engine torque in advance of an upshift occurring, to keep the torque at the wheels relatively constant. However, in the event that an upshift is cancelled after preparation for the upshift has begun, for example due to a change in driver demand, existing systems can react slowly, resulting in undesirable acceleration of the vehicle.

[0003] It is an object of the present invention to address one or more of the drawbacks associated with the prior art. SUMMARY

[0004] Aspects and embodiments of the invention provide control systems, vehicles and methods as claimed in the appended claims.

[0005] According to an aspect of the invention there is provided a control system for controlling a powertrain of a vehicle, the powertrain comprising a power source and a driveline arranged to receive torque from the power source, the driveline comprising a transmission, the control system comprising one or more processors collectively configured to: receive a first input signal, the first input signal comprising information indicative of a torque demand; filter the torque demand to provide a filtered torque demand; determine a primary torque modulation value based at least in part on the torque demand; compare the filtered torque demand to the torque demand; determine an output torque modulation value in dependence on the comparison of the filtered torque demand to the torque demand and the primary torque modulation value; and output a first output signal, the first output signal arranged to cause the power source to vary torque output in dependence on the output torque modulation value.

[0006] According to an aspect of the application there is provided a control system for controlling a powertrain of a vehicle, the powertrain comprising a power source and a driveline arranged to receive torque from the power source, the driveline comprising a transmission, the control system comprising one or more processors collectively configured to: receive a gear change input signal indicative of an anticipated upshift of the transmission; in response to receiving the gear change input signal: receive a first input signal, the first input signal comprising information indicative of a torque demand; filter the torque demand to provide a filtered torque demand; determine a master torque modulation value based at least in part on the torque demand; compare the filtered torque demand to the torque demand; determine an output torque modulation value from the comparison of the filtered torque demand to the torque demand and the master torque modulation value; and output a first output signal, the first output signal arranged to cause the power source to change torque output in accordance with the output torque modulation value.

[0007] Changing the torque output can comprise changing a torque split between a vehicle engine and an electric machine.

[0008] In this way, the control system can prepare for an upshift, for example by increasing torque from the power source, and can interrupt the preparation in the event of a change in torque demand, for example a sudden reduction in torque requirement due to a driver reducing pressure on an accelerator pedal, or a high level driver assistance system (ADAS) requiring less torque after detecting an obstacle.

[0009] According to yet another aspect of the application there is provided computer readable instructions arranged, when executed by a computer, to perform the method of yet another aspect of the application.

[0010] The processors can be collectively configured to determine an arbitration value based on the comparison of the filtered torque demand to the torque demand, and determining the output torque modulation can comprise multiplying the master torque modulation value by the arbitration value. In this way, a processing efficient torque modulation scheme is provided for managing changes in torque demand during an upshift.

[0011] The arbitration value can be between 0 and 1.

[0012] Comparing the filtered torque demand to the torque demand can comprise determining whether the torque demand is decreasing. By determining a reduction in driver torque demand, the system can prepare for a change in powertrain behaviour, for example cancelling an anticipated upshift or reducing vehicle speed. This can provide a more responsive vehicle.

[0013] Filtering the torque demand to provide a filtered torque demand can comprise applying a low pass filter. The low pass filter can filter out short term variations in the torque demand. The difference between the low pass filtered torque demand and the unfiltered torque demand therefore implies a sudden change in the torque demand. In response, the control system can change the torque modulation scheme to cope with the changing torque demand. Furthermore, to manage the traction of the vehicle and the comfort of the passengers, the vehicle typically needs to apply a low pass filter or limit the rate of change of the torque. The filtering step can therefore be dual purpose and the use of a low pass filter can therefore improve computational efficiency.

[0014] The processors can be collectively configured to receive a predicted post-shift torque demand, receive a current torque demand, and determine a primary torque modulation value based on a difference between the predicted post-shift torque demand and the current torque demand.

[0015] The predicted driver torque demand can be based on at least one of an accelerator pedal input, a drive mode, a road gradient, a vehicle speed, and a torque ratio of the driveline after the shift. By using such a predicted driver torque demand and calculating a difference between the predicted torque demand and the current torque demand, a primary torque modulation value can be determined which can be used downstream.

[0016] The processors can be collectively configured to receive or determine a shift cancel signal indicative of a cancellation of the shift, and determine the output torque modulation in dependence on the shift cancel. By taking into account the cancellation of the shift and by modifying the torque modulation accordingly, the system can respond to changes in the environment and / or changes in the driver demand, which can guarantee a faster cancellation of the shift. Furthermore, the behaviour of the power source can be modified to, for example, avoid unwanted acceleration due to excess torque in the absence of a shift.

[0017] The processors can be collectively configured to set the output torque modulation to 0 in response to the shift cancel. In this way, the torque modulation can be effectively cancelled, which means that the vehicle can proceed without unwanted speed changes in response to the cancelled shift.

[0018] The processors can be collectively configured to determine the shift cancel signal based on a comparison of the filtered torque demand and the torque demand.

[0019] The first output signal can be arranged to cause the power source to vary the torque output over time based on a limit on a rate of change of the torque over time. In this way, abrupt changes in the torque can be avoided, providing a limit on the acceleration and deceleration of the vehicle. This can improve the traction of the vehicle and the comfort of the passengers.

[0020] The processors can be collectively configured to vary the limit on the rate of change of the torque over time in dependence on:

[0021] receiving a shift up cancellation signal indicative of a cancellation of a shift up; or

[0022] The shift up cancellation is determined from the comparison of the filtered torque demand to the torque demand and the primary torque modulation value. By varying the limit on the rate of change of torque, the vehicle can react more quickly to changes in torque demand and can avoid unnecessary acceleration. Alternatively, the torque can be reduced more slowly, allowing for a more smooth driving experience.

[0023] The processors can be collectively configured to increase the limit on the rate of change of torque over time when the processors collectively receive or determine the shift up cancellation signal indicative of a cancellation of a shift up. By increasing the limit on the rate of change of torque, the vehicle can react more quickly to changes in torque demand and can avoid unnecessary acceleration.

[0024] According to a further aspect of the application, there is provided a vehicle comprising a control system of the first-mentioned aspect.

[0025] According to a still further aspect of the application, there is provided a method for controlling a powertrain of a vehicle, the powertrain comprising a power source and a driveline arranged to receive torque from the power source, the driveline comprising a transmission, the method comprising: receiving a gear change input signal indicative of a shift up of the transmission; receiving a first input signal, the first input signal comprising information indicative of a torque demand; filtering the torque demand to provide a filtered torque demand; determining a primary torque modulation value based at least in part on the torque demand; comparing the filtered torque demand to the torque demand; determining an output torque modulation based on the comparison of the filtered torque demand to the torque demand and the primary torque modulation value; and outputting a first output signal, the first output signal causing the power source to change the torque output based on the output torque modulation value.

[0026] According to a still further aspect of the application, there is provided computer readable instructions which, when executed by a computer, are arranged to perform the method according to the still further aspect.

[0027] Within the scope of the present application, it is expressly intended that each aspect, embodiment, example and alternative form set forth in the preceding paragraphs, in the claims, and / or in the following description and drawings can be employed independently or in any combination thereof, and particularly that the respective features of any embodiment or example can be employed in any combination unless specifically excluded herein. That is, all possible combinations of features and / or aspects described and / or illustrated herein are intended to be within the scope of the present application. It is also expressly intended that any originally claimed or described aspect, feature, or combination of aspects and / or features can be modified by any of the features, aspects, examples, and / or alternatives described herein, unless otherwise expressly excluded. Furthermore, where a particular feature, aspect and / or combination of particular features and / or aspects is disclosed with respect to a particular aspect, feature and / or combination of features, it is submitted that it is within the purview of applicants to disclose that particular feature, aspect and / or combination of features with respect to any other aspect, feature and / or combination of features except permeated with the features will not be granted. Moreover, it is intended that any methodology, combination of aspects, features, examples, and / or alternatives described or referenced herein can be employed with any other aspect, feature, and / or combination of aspects and / or features unless otherwise indicated. BRIEF DESCRIPTION OF DRAWINGS

[0028] One or more embodiments of the present application will now be described, by way of example only, with reference to the accompanying drawings:

[0029] Figure 1 A vehicle according to an embodiment of the application is shown.

[0030] Figure 2 A schematic diagram of a control system and powertrain of a vehicle according to an embodiment of the application is shown;

[0031] Figure 3 A flowchart illustrating a method according to an embodiment of the application is shown;

[0032] Figure 4 A flowchart illustrating a method according to an embodiment of the application is shown;

[0033] Figure 5 A flowchart illustrating a method according to an embodiment of the application is shown;

[0034] Figure 6a A graph illustrating filtered and unfiltered torque demand is shown; and

[0035] Figure 6b A graph illustrating engine torque modulation is shown. DETAILED DESCRIPTION

[0036] Embodiments of the present application relate to a control system for determining a torque required during an upshift of a vehicle. An upshift is a situation in which a gearbox is actuated to change the gear ratio driven by a power source of a vehicle, such that a "higher" gear is selected, so that the drive train of the vehicle obtains a lower gear ratio. Typically, if the torque does not change at the time of the upshift, the torque on the wheels of the vehicle will decrease. In the case where the vehicle is accelerating, this will be felt by the driver as a decrease in the acceleration of the vehicle.

[0037] Figure 1 A vehicle according to an embodiment of the application is shown to provide context for the present application.

[0038] The vehicle 10 comprises a control system 100 and a powertrain 111. The control system 100 is arranged to control the powertrain 111. The vehicle 10 can be a hybrid electric vehicle having an electric machine and an internal combustion engine, both arranged to drive wheels of the vehicle. The vehicle 10 can be a Mild Hybrid Electric Vehicle (MHEV). A MHEV can be characterized by having no capability to charge the battery using mains electricity, and the battery can only be charged by means of the internal combustion engine and regenerative braking. Considered in another way, the only primary energy source of a MHEV can be fossil fuels, such as gasoline and diesel, and a MHEV can have no electrical connection for charging the battery from an external source. The capacity of the battery of a MHEV can be less than 2 kWh. The battery voltage of a MHEV can be approximately 48 volts or less.

[0039] Alternatively, the vehicle 10 can be a Plug-in Hybrid Electric Vehicle (PHEV). A PHEV can be characterized by being arranged to receive electrical energy from an external source, e.g. via a connection to the mains electricity. Hence, a PHEV can comprise an external electrical connection for charging the battery.

[0040] Figure 2 A schematic view of the control system 100 and the powertrain 111 of the vehicle 10 is shown.

[0041] The 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 driveline coupled to the one or more power sources. The powertrain 111 comprises an internal combustion engine 110, an electric machine 120 and a battery 130 arranged to supply and receive electrical energy 137 to and from the electric machine 120. The internal combustion engine 110 and the electric machine 120 can collectively be referred to as a single power source or two power sources. Both the internal combustion engine 110 and the electric machine 120 transmit torque 117, 127 to a driveline 140 of the powertrain 111. The driveline 140 comprises a gearbox, and can also comprise further components, such as a torque splitter, torque converter, differential and wheels of the vehicle 10.

[0042] It should be appreciated that this merely represents one possible vehicle architecture according to embodiments of the application, and that other vehicle architectures, e.g. architectures having separate electric motors and generators, are also within the scope of the application.

[0043] As Figure 2The illustrated control system 100 includes a controller, although it should be understood that this is merely illustrative. The controller includes a processing device and a memory device. The processing device can be one or more electronic processing devices operable to execute computer-readable instructions. The memory device can be one or more memory devices. The memory device is electrically coupled to the processing device. The memory device is configured to store instructions, and the processing device is configured to access the memory device and execute the instructions stored on the memory device.

[0044] As Figure 2 illustrated, the control system 100 can provide signals 115, 125, e.g., signals 115, 125, to the internal combustion engine 110 and the electric machine 120 to deliver an amount of torque, or in the case of the internal combustion engine 110, advance or retard the ignition timing or increase or decrease the fuel / air mixture flow into the engine 110. The signals can include signals that change the torque distribution between the internal combustion engine 110 and the electric machine 120. The signals can be output by publishing on an on-board network (e.g., a CAN or FlexRay bus), and the signals are received or input by reading the published information. These signals can be described as first output signals.

[0045] The battery 130 can supply electrical energy 137 to the electric machine 120 to generate torque, and can also supply electrical energy 139 to electric vehicle components, such as heaters and fans. The battery can also supply information to the control system 100 about the electrical power 139 supplied to other electrical devices 150.

[0046] The control system 100 can also receive information 135 from the battery 130, such as an indication of the state of charge of the battery, the temperature of the battery, and / or the health of the battery. In general, the information 135 received from the battery can indicate the battery discharge capability, which is the rate at which the battery can supply energy to the electric machine 120 and other electrical devices 150 of the vehicle 10. Alternatively, the battery 130 can output the battery discharge capability directly to the control system 100. The battery 130 can also output information 135 to the control system 100 indicating the electrical power supplied to the electrical devices 150.

[0047] The control system 100 includes input devices and output devices. The input devices can include electrical inputs to the controller 100. The output devices can include electrical outputs from the controller 100. The inputs are arranged to receive signals, and the outputs are arranged to output: signals 115 for controlling the engine 110, including by increasing or decreasing the torque output by the engine; and signals 125 for controlling the electric machine 120, including by increasing or decreasing the torque output by the electric machine.

[0048] The control system 100 is arranged to receive torque demand data 102 from a torque demand input device 101, such as an accelerator pedal, and to determine a required torque to be generated by the engine 110 and the electric machine 120 based at least in part on the received torque demand data 102. The torque demand data 102 can alternatively be received from an advanced driver assistance system (ADAS). The control system 110 can then output control signals 115, 125 to control the engine 110 and the electric machine 120 in order to generate the required torque. The torque demand data 102 can be referred to as a torque demand, or in embodiments where the driver is in manual control of the vehicle, as a driver torque demand. The torque demand data can be a current torque demand.

[0049] An advanced driver assistance system (ADAS) is a system that provides an assisted or automated driving mode, such as a speed limiter, cruise control, adaptive cruise control. The ADAS can provide a torque demand that is not related to driver pedal input.

[0050] The control system 100 is also arranged to receive a driving mode signal 104 from a driving mode selector 103, which can take the form of a driving mode selector switch, or can be taken from a touchscreen or other such input to a human-machine interface of the vehicle. The driving mode can be selected by the driver according to the desired behaviour of the vehicle. For example, a "sport" mode can be selected when it is desired that the vehicle reacts quickly to driver input and achieves high acceleration, whereas a "comfort" mode can be selected when a less sensitive driving mode is desired. The control system 100 can determine the required torque based at least in part on the driving mode signal 104.

[0051] The control system 100 is also arranged to receive a vehicle condition signal 106 from a vehicle condition sensor 105. The vehicle condition sensor can determine properties such as road slope and vehicle speed, and the vehicle condition signal 106 can contain this information. The control system 100 can receive the vehicle condition signal 106, and can determine the required torque based at least in part on information in the vehicle condition signal, such as road slope and / or vehicle speed.

[0052] The control system is also configured to receive driveline data 108 from a driveline management system 107. The driveline management system 107 can also be referred to as a transmission control system or a transmission management system. The driveline control system 107 can provide the driveline data 108, and the driveline data 108 can include information such as a target gear after a shift up, a gear change signal indicating that a shift up is imminent, a torque converter slip value indicating a slip level of a torque converter from the driveline 140, and a predicted gearbox input shaft speed after a shift up.

[0053] The control system 100 can also have internally stored values such as the gear ratios of the different gears, the maximum capability of the powertrain torque, the blend rate used to change the torque output of the powertrain 140, and a loss value indicative of the loss of torque in the powertrain.

[0054] The control system 100 can determine the predicted driver torque for the target gear based on any or all of the above data, and thus can more effectively determine the predicted torque required for the target gear. Furthermore, the data included in the separate signals 102, 104, 106, 108 can be combined by a signal management system and received by the control system 100 as a single signal.

[0055] The term control system can be used to describe a particular control module, or to describe a system of sensors and modules. For example, the powertrain control module 107, the torque demand input device 101, the drive mode selection device 103, and the vehicle condition sensors 105 can be considered to be within the same control system as the control system 100. Where a control system is described as being arranged to receive a signal, it will also be understood that one part or program of the control system can receive the signal from another part or program of the control system, and that it is not essential for the signal to be sent from a device external to the control system to a physically separate control system.

[0056] Figure 3 A flowchart illustrating a method 200 for controlling a powertrain during a change in the mind of a driver is shown, a change in the torque demand from an ADAS or a change in the torque demand from an autonomous driving program can be detected during an upshift and can affect the torque demand. In particular, the illustrated method relates to a reduction in the torque demand.

[0057] At step 210, a gear change signal is received by the control system 100 indicating an anticipated upshift. In response, the control system 100 enters an upshift management mode for determining the required torque from the power source during the upshift.

[0058] At step 220, a first input signal is received including information indicative of a torque demand signal. The torque demand signal can be received from a torque input device such as a driver pedal, an ADAS, or an autonomous driving program. The torque demand can also be pre-processed to some extent, for example by taking into account the driver mode or the vehicle speed. Reference is made below to Figure 4 Further description of possible processing of the torque demand.

[0059] At step 220, the received torque demand is filtered to provide a filtered torque demand. Filtering can also be referred to as "driveability shaping" and can include passing the torque demand through a low pass filter or limiting the rate of change of torque over time. Filtering can improve the traction of the vehicle by reducing high frequency changes in torque and can also provide a more comfortable experience for passengers. Figure 6 shows how the torque demand can be filtered.

[0060] At step 230, the filtered torque demand is compared to the unfiltered torque demand. A significant difference indicates that the torque demand is changing rapidly and there can be a change in the driver's mind or a change in the intent of the ADAS or autonomous driving program. In particular, if the unfiltered torque demand is significantly less than the filtered torque demand, there is an implication that the acceleration of the vehicle should stop or decrease.

[0061] In response to the determination as to whether the acceleration of the vehicle should decrease, the system can determine a torque modulation arbitration value at step 230. In the case that the acceleration should decrease, or generally the torque demand is decreasing, the determined torque modulation arbitration value can be less than 1. In the case that a shift up should not occur due to a significant decrease in torque demand, a torque modulation arbitration value of 0 can be selected. In the case that the torque demand matches the filtered torque demand, which means that a shift up should occur as expected, a torque modulation arbitration value of 1 can be selected. The torque modulation arbitration value can be considered to be a ratio of how much of the torque modulation value should be passed to the downstream control logic.

[0062] Furthermore, in the case that it is determined that the torque demand has decreased such that a shift up should not occur, a shift up cancel signal can be output by the control system 100 to indicate to the transmission control system that the transmission should not be actuated to shift up. Alternatively, the shift up cancel signal can be output by the transmission control system, which can determine the decrease in torque demand. Thus, the control system 100 can receive the shift up cancel signal either by way of a publication on a CAN bus or by receiving a signal from the transmission control system.

[0063] Generally, the control system can limit the rate of change of torque to improve the driveability of the vehicle. In response to receiving a shift up cancel signal or otherwise determining that a shift up can be cancelled, the control system 100 can change the maximum torque decrease rate. This can include increasing the maximum torque decrease rate. In this way, the power source can have a higher rate of torque decrease than in the case where no shift up cancel signal is received or determined. In this case, the torque can decrease more quickly to match the determined torque modulation.

[0064] At step 240, a torque modulation value is determined by the control system 100. The torque modulation value can be determined using different torque modulation schemes based on the source of the torque demand. In the case where the torque demand is from a driver torque input device, such as an accelerator pedal, a predicted post-shift torque demand can be determined as set out below in connection with Figure 4 The current torque demand can be subtracted from the predicted post-shift torque demand to give the torque modulation value. Alternatively, in the case where the ADAS is the source of the torque demand, the torque modulation value can be determined based on the current torque demand, the current torque ratio of the gearbox and the post-shift torque ratio of the gearbox. The torque modulation value can be determined such that the torque output from the gearbox does not change during the shift.

[0065] As shown in Figure 3 Step 220 and step 230 can be performed in parallel with step 240. Alternatively, step 240 can be performed before or after step 220 and step 230. This can be advantageous in cases where a determined value such as the filtered torque demand can be used in both processes.

[0066] The torque modulation value and the torque arbitration value can be combined at step 250, for example by multiplication, to output a final torque modulation value.

[0067] At step 260, the torque modulation value can be output to the power source to change the torque generated by the power source. Alternatively, the torque modulation can be added to the current torque demand to determine an absolute torque demand. The absolute torque demand can then be output to the power source to cause the power source to generate a torque equal to the absolute torque demand.

[0068] Figure 4 A further flowchart is shown which illustrates how data received by the control system can be processed for determining a predicted driver torque after a shift. A first processing step 310 can receive inputs from various sources. In particular, the process 310 can receive an accelerator pedal input 301, a previous driver or terrain mode 302, a current driver or terrain mode 303, a road slope 304, a vehicle speed 305, a high or low range requirement 306, a target gear ratio excluding torque converter slip 307, a drive or sport selection 308, and a predicted gearbox input shaft speed for the target gear 309. Based on the inputs 301 to 309, the process 310 generates a normalised torque demand 315. A second process 320 calculates a predicted torque demand for the target gear based on the normalised torque demand 315. The second process 320 calculates the predicted torque demand 330 for the target gear based on losses known within the powertrain 321, the gear ratio of the target gear 322 and the maximum torque capability of the powertrain 323.

[0069] By following process 300, a more accurate predicted torque demand 330 for the target gear can be determined.

[0070] Figure 5 A further flowchart illustrating a method 400 for determining a torque modulation value 445 is shown. The control system receives a torque demand 401. At step 410, the torque demand is filtered to provide a filtered torque demand 415. Step 420 receives the original, unfiltered torque demand 401 and the filtered torque demand 415 to determine whether the torque demand is decreasing. This comparison can be performed as described below with reference to FIG6. Based on this comparison, a torque modulation arbitration value 425 is determined.

[0071] At step 430, the torque modulation value 435 is determined. Figure 5 In the illustrated method, the torque modulation value 435 is determined based on the predicted upshift torque demand 403 and the current torque demand 405. The predicted upshift torque demand 403 can be referred to above. Figure 4 The torque demand 401 can be determined as described. The original, unfiltered torque demand 401 can be the same as the current torque demand 405. The torque modulation 435 can be determined based on the difference between the predicted upshift torque demand 403 and the current torque demand 405.

[0072] At step 440, a final torque modulation value 445 is determined based on the torque modulation value 435 and the torque modulation arbitration value 425. The final torque modulation value 445 can be determined by multiplying the torque modulation value 435 by the torque modulation arbitration value 425.

[0073] Figure 6 shows a graph 500 of the original torque demand 510 and the filtered torque demand 520. It can be seen that the original torque demand 510 may change abruptly. This could be due to the driver lifting their foot off the accelerator pedal, or due to the ADAS detecting an obstacle in the vehicle's path and instructing deceleration. To improve traction and passenger comfort, the original torque demand 510 can be filtered. Filtering may include removing high-frequency components of the original torque demand and / or limiting the rate of change of the torque demand. In this way, the filtered torque demand 520 is determined.

[0074] As from Figure 6a As can be seen, due to the high rate of change of the original torque demand 510, the filtered torque demand 520 deviates significantly from the original torque demand 510. By comparing the contemporary values ​​of the filtered torque demand 520 and the original torque demand 510, it can be determined whether the original torque demand 510 includes the high rate of change of torque. Furthermore, if the filtered torque demand 520 is greater than the original torque demand 510, it can be determined that the original torque demand 510 is decreasing. Figure 6bThe logic is shown to include detection of whether the shift is ongoing 531 or has been interrupted 530, which will result in different optional reduction rates 541 and 540 for the filtered upshift torque modulation, respectively.

[0075] The rate of change of torque for the filtered torque demand 620 can be optional, such that filtering can be performed to provide vehicle stability and avoid sudden changes in vehicle behavior.

[0076] Based on a determination that the original torque demand 510 is decreasing at a high rate, the torque modulation arbitration value 425 can be selected accordingly, providing an appropriate final torque modulation value 445. In this way, in the event that the required torque is changing significantly during an upshift, the torque generated by the power source can be effectively managed during the upshift.

[0077] It will be understood that various changes and modifications can be made to the application without departing from the scope thereof.

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, the control system including one or more processors, the one or more processors being collectively configured to: Receive a gear change input signal indicating a desired upshift in the transmission; In response to receiving the gear change input signal, the system enters upshift management mode, and in the upshift management mode: Receive a first input signal, the first input signal including information indicating torque demand; The torque demand is filtered to provide a filtered torque demand; The main torque modulation value is determined at least in part based on the torque requirement; The filtered torque requirement is compared with the torque requirement; The output torque modulation value is determined based on the comparison between the filtered torque demand and the torque demand, and the main torque modulation value. as well as A first output signal is output, which is configured to cause the power source to change its torque output according to the output torque modulation value.

2. The control system according to claim 1, wherein, The processors are collectively configured to determine an arbitration value based on a comparison between the filtered torque demand and the torque requirement, wherein determining the output torque modulation includes multiplying the main torque modulation value by the arbitration value.

3. The control system according to claim 2, wherein, The arbitration value is between 0 and 1.

4. The control system according to claim 1, 2 or 3, wherein, Comparing the filtered torque demand with the torque demand includes determining whether the torque demand is decreasing.

5. The control system according to any of the preceding claims, wherein, Filtering the torque demand to provide a filtered torque demand includes applying a low-pass filter.

6. The control system according to any of the preceding claims, wherein, The processors are collectively configured to: Receive the predicted torque demand after upshifting. Receive the current torque demand, and The main torque modulation value is determined based on the difference between the predicted torque demand after the upshift and the current torque demand.

7. The control system according to any of the preceding claims, wherein, The processors are collectively configured to: Receive or confirm an upshift cancellation signal indicating cancellation of the upshift, and The output torque modulation is determined based on the upshift cancellation.

8. The control system according to claim 7, wherein, The processors are collectively configured to set the output torque modulation to 0 in response to upshift cancellation.

9. The control system according to claim 7 or 8, wherein, The processors are collectively configured to determine the upshift cancellation signal based on a comparison between the filtered torque demand and the torque requirement.

10. The control system according to any of the preceding claims, wherein, The first output signal is configured to cause the power source to change its torque output over time based on a limitation on the rate of change of torque over time.

11. The control system according to claim 10, wherein, The processors are collectively configured to change the limit on the rate of change of torque over time according to the following: Receive an upshift cancellation signal indicating that the upshift is to be cancelled; or The upshift cancellation is determined based on the comparison between the filtered torque demand and the torque demand, and the main torque modulation value.

12. The control system according to claim 11, wherein, The processors are collectively configured to improve the limitation on the rate of change of torque over time.

13. A vehicle comprising a control system according to any of the preceding claims.

14. A method for controlling a powertrain of a vehicle, 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: Receive a gear change input signal instructing the transmission to shift up; In response to receiving the gear change input signal, the system enters upshift management mode, and in the upshift management mode: Receive a first input signal, the first input signal including information indicating torque demand; The torque demand is filtered to provide a filtered torque demand; The main torque modulation value is determined at least in part based on the torque requirement; The filtered torque requirement is compared with the torque requirement; The output torque modulation is determined based on the comparison between the filtered torque demand and the main torque modulation value. as well as A first output signal is output, which causes the power source to change its torque output based on the output torque modulation value.

15. A computer-readable instruction, which, when executed by a computer, is arranged to perform the method according to claim 14.

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