Dynamic torque fill

Abstract

A system for controlling torque in a vehicle includes first and second propulsion systems, the first propulsion system including an internal combustion engine configured to drive a primary shaft, the second propulsion system including an electric motor configured to drive a secondary shaft, where the first propulsion system and the primary shaft are mechanically independent of the second propulsion system and the secondary shaft. The controller is configured to execute a method including: estimating a first amount of torque applied to the spindle in response to a spindle torque request; determining a difference between a first amount of torque applied to the spindle and the spindle torque request; and based on the difference exceeding a selected threshold, calculating a dynamic fill torque and applying a second amount of torque to the countershaft by the electric motor according to the calculated dynamic fill torque.

Description

Technical Field

[0001] The present invention relates to vehicles, and more particularly, to systems, devices, and methods for controlling vehicle propulsion. Background Art

[0002] Vehicles, including gasoline and diesel-powered vehicles, fuel cell vehicles, and electric and hybrid electric vehicles, have a variety of propulsion systems. Different propulsion systems have different response times (i.e., the delay in converting a driver's torque request into actual acceleration or deceleration). For example, an internal combustion engine (ICE) system has a delayed response due to various factors such as ignition timing, throttle parameters, etc. There is a desire to provide systems that can compensate for such delayed responses in order to increase driving performance, improve responsiveness, and enhance the overall driver experience. Summary of the Invention

[0003] In one exemplary embodiment, a system for controlling torque in a vehicle includes a controller coupled to a first propulsion system and a second propulsion system of the vehicle. The first propulsion system includes an internal combustion engine configured to drive a main shaft, and the second propulsion system includes an electric motor configured to drive a secondary shaft, wherein the first propulsion system and the main shaft are mechanically independent of the second propulsion system and the secondary shaft. The controller is configured to perform a method including: estimating a first torque amount applied to the main shaft in response to a main shaft torque request; determining a difference between the first torque amount applied to the main shaft and the main shaft torque request; and based on the difference exceeding a selected threshold, calculating a dynamic fill torque and applying a second torque amount to the secondary shaft through the electric motor according to the calculated dynamic fill torque.

[0004] In addition to one or more features described herein, the main shaft torque request is a shaped torque request determined based on a vehicle operation mode.

[0005] In addition to one or more features described herein, the dynamic fill torque is configured to fill a dynamic fill torque curve, and the dynamic fill torque curve is calculated by limiting the shaped torque request based on the difference.

[0006] In addition to one or more features described herein, the main shaft torque request is selected from a torque request provided by a control system and an expected torque request, and the expected torque request is based on a driver input applied to an accelerator pedal, and the driver input includes at least one of a position of the accelerator pedal and a movement of the accelerator pedal.

[0007] In addition to one or more features described herein, the difference exists between the estimated first torque amount and the expected torque request.

[0008] In addition to one or more features described herein, the controller is configured to initiate a method based on at least one activation criterion, the activation criterion including a minimum displacement of a pedal, a minimum magnitude of a first torque amount applied to the main shaft, and a minimum rate of change of the first torque amount.

[0009] In addition to one or more features described herein, the controller is configured to limit the magnitude and / or rate of a second torque amount.

[0010] In addition to one or more features described herein, the method includes limiting the second torque amount based on at least one of: a charge state of a battery assembly connected to an electric motor, a lateral acceleration, a vehicle operation mode, and a capacity of a countershaft.

[0011] In addition to one or more features described herein, the vehicle includes a battery assembly connected to an electric motor, and the controller is configured to stop applying the second torque amount based on the charge state of the battery assembly being below a charge state threshold.

[0012] In addition to one or more features described herein, the method includes calculating a total torque amount by summing a dynamic fill torque and the first torque amount, and eliminating the application of the second torque amount based on a main shaft torque request exceeding the total torque amount during a selected time period.

[0013] In another exemplary embodiment, a method of controlling torque in a vehicle includes detecting a main torque request for applying torque to a main shaft of the vehicle, the vehicle including a first propulsion system and a second propulsion system, the first propulsion system including an internal combustion engine configured to drive the main shaft, the second propulsion system including an electric motor configured to drive a countershaft, wherein the first propulsion system and the main shaft are mechanically independent of the second propulsion system and the countershaft. The method further includes: estimating a first torque amount applied to the main shaft in response to the main shaft torque request; determining a difference between the first torque amount applied to the main shaft and the main shaft torque request; and based on the difference exceeding a selected threshold, calculating a dynamic fill torque and applying a second torque amount to the countershaft via the electric motor based on the calculated dynamic fill torque. [[ID=!7]]

[0014] In addition to one or more features described herein, the main shaft torque request is a shaped torque request determined based on a vehicle operation mode.

[0015] In addition to one or more features described herein, the dynamic fill torque is configured to a dynamic fill torque curve, and the dynamic fill torque curve is calculated by limiting the shaped torque request based on the difference.

[0016] In addition to one or more features described herein, the main shaft torque request is selected from a torque request provided by a control system and an expected torque request, the expected torque request being based on driver input applied to an accelerator pedal, the driver input including at least one of a position of the accelerator pedal and a movement of the accelerator pedal, and wherein a difference exists between the estimated first torque amount and the expected torque request.

[0017] In addition to one or more features described herein, the method is initiated based on at least one activation criterion, the activation criterion including a minimum displacement of the pedal, a minimum magnitude of a first torque amount applied to the main shaft, and a minimum rate of change of the first torque amount.

[0018] In addition to one or more features described herein, the method includes limiting a second torque amount based on at least one of: a state of charge of a battery assembly connected to an electric motor, a lateral acceleration, a vehicle operating mode, and a capacity of a secondary shaft.

[0019] In yet another exemplary embodiment, a vehicle system includes: a first propulsion system including an internal combustion engine configured to drive a vehicle main shaft; a second propulsion system including an electric motor configured to drive a secondary shaft, wherein the first propulsion system and the main shaft are mechanically independent of the second propulsion system and the secondary shaft; and a processing device for executing computer-readable instructions from a memory, the computer-readable instructions controlling the processing device to execute a method. The method includes detecting a main torque request shaft for applying torque to the main shaft; estimating a first torque amount applied to the main shaft in response to the main shaft torque request; determining a difference between the first torque amount applied to the main shaft and the main shaft torque request; and based on the difference exceeding a selected threshold, calculating a dynamic fill torque and applying a second torque amount to the secondary shaft by the electric motor according to the calculated dynamic fill torque.

[0020] In addition to one or more features described herein, the main shaft torque request is a shaped torque request determined based on a vehicle operating mode, and the dynamic fill torque is configured as a dynamic fill torque curve, the dynamic fill torque curve being calculated by limiting the shaped torque request based on the difference.

[0021] In addition to one or more features described herein, the main shaft torque request is selected from a torque request provided by a control system and an expected torque request, the expected torque request being based on driver input applied to an accelerator pedal, the driver input including at least one of a position of the accelerator pedal and a movement of the accelerator pedal, and wherein a difference exists between the estimated first torque amount and the expected torque request.

[0022] In addition to one or more features described herein, the method initiates the method based on at least one activation criterion, the activation criterion including a minimum displacement of the pedal, a minimum magnitude of a first torque amount applied to the main shaft, and a minimum rate of change of the first torque amount.

[0023] The above features and advantages of the present disclosure, as well as other features and advantages, will become apparent when the following detailed description is read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 is a top view of a motor vehicle according to an exemplary embodiment;

[0026] Figure 2 depicts a torque control system configured to control the torque applied to a vehicle according to an exemplary embodiment;

[0027] Figure 3 depicts a processing system configured to perform a dynamic torque fill method according to an exemplary embodiment, and depicts aspects of the torque fill method;

[0028] Figure 4 is a block diagram depicting Figure 3 aspects of the torque fill method; and

[0029] Figure 5 depicts a computer system according to an exemplary embodiment. DETAILED DESCRIPTION

[0030] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that in all the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0031] According to an exemplary embodiment, methods, devices, and systems for controlling vehicle propulsion are provided. In one embodiment, the vehicle includes a main shaft powered by a relatively slow-acting propulsion source (e.g., an internal combustion engine) and a secondary shaft powered by a relatively fast-acting torque source (e.g., an electric motor). The slow-acting propulsion source is separated from the fast-acting propulsion source (i.e., there is no torque coupling or mechanical coupling allowing torque to be transferred between the respective shafts driven by the propulsion sources; the only coupling is through the driving surface or road). The fast-acting propulsion source is controlled to compensate for the delayed response of the internal combustion engine and to match vehicle performance to torque requirements. This control achieves an improvement in driving performance, vehicle responsiveness, and overall performance.

[0032] Embodiments of the method include receiving a propulsion request from a driver (e.g., via pressure applied to a pedal and / or pedal movement), and determining a main shaft torque request (estimating the amount of torque requested to be applied to the main shaft). The method includes estimating the amount of torque actually applied to the main shaft ("applied torque" or "transmitted torque"), and calculating the difference between the transmitted torque and the propulsion request, or the difference between the transmitted torque and the main shaft torque request. A dynamic torque fill process is performed to eliminate the difference, thereby compensating for the delay in torque transmission.

[0033] In one embodiment, the propulsion request corresponds to an expected torque request, which is estimated based on detecting pedal position and / or movement. The expected torque request is estimated based on the detected pedal position and / or movement in order to capture the driver's actual intent. In this embodiment, the difference exists between the expected torque request and the transmitted torque.

[0034] Embodiments can be incorporated into various vehicle features and operating modes. For example, embodiments can be used during a high-performance mode and incorporated into features such as 12-volt stop / start, quick start, roll neutral, dual clutch disengagement, and switching to neutral and back to drive.

[0035] The embodiments described herein present many advantages and technical effects. Compared to using slower-acting propulsion sources alone, these embodiments improve drivability and the driver experience by providing improved transient response. For example, the dynamic torque fill method meets the desired transient requirements typically reserved for electric vehicles. This enables the driver to experience the best parts of driving an electric vehicle and the best parts of driving an ICE vehicle (e.g., the smoothness and immediacy of torque response, and the feel and sound of an internal combustion engine). Additionally, utilizing a fast-response propulsion source as described herein allows for a more dynamic vehicle response, with significantly fewer rollover bumps or dull metallic sounds compared to other vehicles.

[0036] Embodiments also provide for the effective use of existing vehicle systems to improve performance and drivability. For example, the dynamic torque fill method can utilize existing tools and math-based dynamic target calibrations, using existing torque request logic as the basis for torque fill. Additionally, the dynamic response described herein can be achieved without re-calibrating or re-designing the main shaft control. Furthermore, embodiments are capable of using a significantly lower-cost and less complex hardware architecture (e.g., no electric motor between the ICE and the transmission) and providing equivalent or better dynamic response.

[0037] Embodiments are not limited to use with any particular vehicle and can be applicable to a variety of situations. For example, embodiments can be used in automobiles, trucks, construction equipment, farm equipment, automated factory equipment, and / or any other device or system having multiple propulsion systems.

[0038] Figure 1An embodiment of a motor vehicle 10 is shown, which includes a vehicle body 12 that at least partially defines an occupant compartment 14. The vehicle body 12 also supports various vehicle subsystems, including propulsion systems 16 and 18, as well as other subsystems and other vehicle components that support the functions of the propulsion systems 16 and 18, such as a braking subsystem, a suspension system, a steering subsystem, and if the vehicle is a hybrid electric vehicle, also a fuel injection subsystem, an exhaust subsystem, etc.

[0039] In one embodiment, the propulsion systems 16 and 18 form at least a part of a hybrid system that includes at least two independent torque generating devices. These devices are independent because they are independently controllable and there is no mechanical coupling within the vehicle 10 and between the devices (except for any coupling with the driving surface or road).

[0040] For example, the propulsion system 16 includes an internal combustion engine 20 and a transmission system 22. The transmission system 22 includes a gearbox 24 for transmitting torque from the engine 18 to a drive shaft 26, which is also referred to as a main shaft 26. The drive shaft 26 is connected to the front wheels 28.

[0041] The transmission system 22 is configured to operate in various selectable fixed gear operating modes and is controllable to match the transmission ratio operation of the driver's propulsion request and the engine operating point. Various differential gear sets and a hydraulic starting clutch are included to achieve torque transmission. Examples include an automatic transmission, a dual clutch transmission, a clutchless manual transmission, and a manual transmission. In response to an output torque request, the transmission 22 performs an upshift to switch to an operating mode with a lower numerical ratio (transmission ratio), and performs a downshift to switch to an operating mode with a higher numerical ratio. Alternatively, the transmission 22 can be configured as a continuously variable transmission.

[0042] The propulsion system 18 is configured as an electric drive system, including at least one electric motor 30 and at least one inverter 32. The inverter 32 (such as a traction power inverter unit or TPIM) converts direct current (DC) power from a high voltage (HV) battery pack 52 into polyphase (such as two-phase, three-phase, six-phase, etc.) alternating current (AC) power to drive the motor.

[0043] The motor 30 is connected to a driveline 34, which includes a gearbox 36 for controlling the transmission of torque from the motor 30 via a drive shaft 40 to the rear wheels 38. The drive shaft 40 can also be referred to as a countershaft 40.

[0044] One or more processing devices are included to control the operation of the propulsion system. The one or more processing devices are configured to control the torque output of the propulsion system based on a driver torque request, which can be provided by an accelerator pedal 48.

[0045] In one embodiment, an engine control unit (ECU) 42 is configured to receive a torque request and control the engine 20, and a motor control unit (MCU) 44 is configured to control the torque applied by the motor 30. As described herein, a processing device referred to as controller 46 may be provided to process the torque request and coordinate the control of the propulsion system. Note that the embodiments are not limited thereto, and any number of processing devices or combinations thereof may be used.

[0046] As Figure 1 shown, the propulsion systems 16 and 18 are configured such that the engine 20 drives the front wheels 28, and the electric motor 30 can be used to provide compensatory torque to the rear wheels 38. However, the embodiments are not limited thereto, as any number of propulsion systems and / or motors may be at different locations (e.g., one motor drives one wheel, dual motors per axle, etc.). For example, the engine 20 may be configured to apply torque to the drive shaft 40, while the motor 30 may be configured to apply torque to the drive shaft 26 (the drive shaft 40 would be the main shaft and the drive shaft 26 would be the auxiliary shaft).

[0047] The motor 30, as well as other vehicle components, are electrically connected to the battery system 50. The battery system 50 may be configured as a rechargeable energy storage system (RESS).

[0048] In one embodiment, the battery system 50 includes a battery assembly, such as a battery pack 52. The battery pack 52 includes a plurality of battery modules 54, where each battery module 54 includes a plurality of cells (not shown). The battery system 50 may also include a monitoring unit 56 (e.g., a RESS controller) configured to receive measurements from various sensors. Sensors may be provided for measuring various battery and environmental parameters, such as temperature, current, and voltage.

[0049] The vehicle 10 also includes a computer system 60 that includes one or more processing devices 62 and a user interface 64. The computer system 60 may communicate with the controller 46 and / or other processors, for example, to provide commands (e.g., torque commands) thereto in response to user input. The various processing devices, modules, and units may communicate with each other via a communication device or system (e.g., a controller area network (CAN) or a transmission control protocol (TCP) bus).

[0050] Generally, the response time of an electric machine such as the motor 30 is many times faster than that of an internal combustion engine such as the engine 20. As a result, there is a delay in applying the desired torque to the vehicle 10 within the required time frame. Additionally, the delay can result in impaired driving performance.

[0051] For example, due to waiting times associated with intake manifold fill times, transmission gear changes, and other factors, engine 18 may take 100 to 500 ms to respond to a request to affect a change in engine torque output. The response time of motor 30 is significantly faster (e.g., 10 - 20 ms).

[0052] To address and compensate for this delay, a processing device (e.g., controller 46) is configured to perform a dynamic torque fill method that includes monitoring torque on vehicle 10 and a torque request provided by a driver (or autonomous control system). Upon detecting a torque request, an actual expected torque on a main shaft (e.g., drive shaft 26) is calculated based on the torque request, and a difference between the torque request and the actual expected torque is calculated. If a difference exists, the method includes controlling a fast torque device, such as an electric motor connected to a countershaft (e.g., controlling motor 30 connected to drive shaft 40), to automatically and in real time apply a compensating torque to the countershaft.

[0053] In one embodiment, the torque request is a variable torque request (i.e., having a non - constant torque profile over a selected time period) that is derived based on driver input (pedal movement) and other variables. The variable torque request is also referred to as a shaped torque request (STR) and is configured to prescribe a torque curve with smoothly varying torque and acceleration. In this embodiment, the processing device uses the STR as an input and provides dynamic torque fill by analyzing the STR relative to the measured torque. In another embodiment, the processing device analyzes pedal position and / or movement to determine the driver's actual intent and provides dynamic torque fill based on an estimate of the driver's expected torque request.

[0054] Figure 2 An example of a control system 80 is depicted that is configured to perform various aspects of the torque control and dynamic torque fill described herein. Note that control system 80 is not limited to any particular configuration.

[0055] Control system 80 includes a driver - shaft torque module 82 that determines a main - shaft torque request as described herein. Driver - shaft torque module 82 includes a pedal - request module 84. Pedal - request module 84 determines a pedal torque request (PTR). The pedal torque request can be in terms of the propulsion torque domain (i.e., the torque of the crankshaft or other input to the driveline).

[0056] The PTR is determined based on the position of the pedal 48 (accelerator pedal position (APP) 86), vehicle speed information 88, and other suitable parameters. The PTR is fed to a conversion module 90 that converts the PTR into the axle torque domain (i.e., the torque at the wheels or axles). After being converted into the axle torque domain, the PTR may be referred to as the driver torque request. The conversion module 90 converts the PTR based on, for example, driveline losses, the selected gear ratio within the transmission, one or more torque ratios, and / or other suitable parameters.

[0057] The torque request arbitration module 92 receives the driver torque request and other torque requests 94 and arbitrates between the received requests. For example, the arbitration module 92 may arbitrate between torque requests related to longitudinal propulsion, such as the driver torque request and the cruise torque request. The arbitration module 92 outputs the winner of such arbitration. The winner may be output to the transient acceleration request module (TARM) 96 and the torque shaping module 98, which are discussed further herein.

[0058] In some cases, arbitration between the longitudinal propulsion torque request and other torque requests that are not primarily for longitudinal propulsion purposes (e.g., from chassis control interventions such as stability control) may result in bypassing the TARM 96 and the torque shaping module 98. For example, if arbitration between the longitudinal propulsion torque request and other torque requests 94 (i.e., requests that are not primarily for longitudinal propulsion) results in another torque request 94 winning, then that another torque request 94 may be provided directly to the torque transfer module 100 and / or provided to other modules (not shown).

[0059] The output of the arbitration module 92 to the TARM 96 is the winner of the arbitration and represents the original axle torque request (e.g., in Newton - meters) and may be referred to as the driver torque target (DTT). The original axle torque request is in terms of the axle torque domain (i.e., the torque at the wheels or axles). As further described herein, the transient acceleration request module (TARM) 96 may operate on the DTT.

[0060] The TARM 96 may receive the original axle torque request or the DTT from the arbitration module 92. The TARM 96 may employ one or more calibration tables or maps relating the axle torque request to a torque rate limit for shaping the original axle torque request into a shaped torque request (STR), as described in further detail herein. Thus, the STR may have different shapes for different operating modes (drive modes) and different arbitration winners.

[0061] For example, a calibration table can correlate a desired change in axle torque with a desired rate of change in axle torque (torque profile) to achieve a vehicle acceleration response based on a desired acceleration response. For example, TARM96 shapes the raw axle torque request to ensure smooth acceleration, deceleration, and torque changes, resulting in a pleasant experience for the driver. In this way, abrupt or sudden changes in torque are prevented to reduce or prevent the "jerking" or "snapping" sensations that may be experienced when the driver exhibits an active or jittery accelerator pedal, without being subject to perception constraints.

[0062] It should be understood that the calibration and discussion here are in the torque domain, more specifically in the axle torque domain; however, vehicle performance / drivability development may initially occur in the acceleration domain and later be translated to the axle torque domain for control applications. The calibration table used here can include calibration elements, calibration arrays, calibration tables, or combinations and libraries thereof. The described calibration table can be applicable to different driving styles or conditions (driving modes), such as touring, sport, snow, closed track, four-wheel drive low or high speed, etc. Similarly, a multi-dimensional library of such calibration tables can be defined and accessed by the driving mode dimension.

[0063] TARM96 can provide a shaped torque request (STR) to the shaping module 98 for additional torque shaping. For example, in a powertrain capable of distributing the total axle torque between different axles or to individual vehicle corners, the shaping module 98 can further adapt the shaped torque request (STR) for such distribution. The shaped torque request STR is in terms of the axle torque domain (i.e., the torque at the wheels or axles).

[0064] The shaped torque request STR is passed to the torque transfer module 100 and represents the currently transferred or controlled axle torque. The torque transfer module 100 receives the shaped torque request STR and determines the spindle torque request. The torque transfer module 100 can include an axle torque arbitration module 102 for arbitrating with other axle torque requests. The axle torque arbitration module 102 arbitrates between the shaped torque request STR from the shaping module 98 and other axle torque requests such as the axle torque intervention 104. The axle torque intervention 104 can come from the driveline dynamic management (DDM), which is mainly used for so-called dull metal noise region or clearance region management to mitigate undesired driveline gear meshing disturbances (i.e., operator-discernible noise and jolts) during torque reversals or applications from a stationary state (dynamic dull metal noise control or DCC).

[0065] Other axle torque interventions 104 can also include a torque reduction requested by a traction control system when positive wheel slip is detected. Positive wheel slip can occur when the axle torque (i.e., the torque to the wheel) overcomes the friction between the wheel and the road surface, and the wheel slips relative to the road surface in the forward direction. Other axle torque interventions 104 can also include a torque increase request to counteract negative wheel slip, where the vehicle's tire slips or drags relative to the road surface in the opposite direction because the axle torque is negative. Other axle torque interventions can also include various brake management requests and other axle torque impact controls of the powertrain that relate to, for example, vehicle stability and tracking management, collision avoidance, early collision mitigation and preparation, etc. The torque transfer module 100 can generally set the master vehicle request (e.g., Nm) to be equal to the shaped torque request STR, unless other axle torque requests or interventions of higher priority are required.

[0066] The main shaft torque request is passed to the actuation module 106, which determines how the final main shaft request will be achieved. The actuation module 106 can be powertrain-specific. For example, for a spark ignition engine and a compression ignition engine, the actuation module 106 can be implemented differently or use different control schemes. For example, in a spark ignition engine, the actuation module 106 can change the throttle opening as a slow actuator that allows a wide range of torque control. The actuation module 106 can use a cylinder actuator module to disable cylinders, which also provides a wide range of torque control but can also be slow and may involve driveability and emissions issues.

[0067] In one embodiment, the main shaft torque request is provided to a main shaft driven by an internal combustion engine, such as main shaft 26 ( Figure 1 ). In such an embodiment, during the operation of the actuation module 106 and the application of torque to the main shaft, the main shaft torque request is passed to the dynamic torque fill module 108. Generally, the dynamic torque fill module 108 estimates the amount of torque applied to the main shaft (e.g., via torque and / or speed sensors) and compares the estimated torque with the torque request.

[0068] The torque request can be the main shaft torque request provided to the actuation module 100. Additionally or alternatively, the dynamic torque fill module 108 determines the driver's "expected torque request", which is based on monitoring or detecting the driver's input through an accelerator pedal (e.g., Figure 1 pedal 48). For example, position sensors, acceleration sensors, motion sensors, and / or other suitable sensors are used to detect the nature and extent of the driver's engagement with pedal 48. The pedal movement and / or position are used to determine the driver's actual intent (i.e., the amount of torque the driver wants to request).

[0069] The torque fill module 108 obtains sensor information or data from another monitoring system, estimates the actual torque amount (also referred to as "main torque" or "actual main torque"), and determines the difference between the spindle torque request (or desired torque request) and the actual main torque. If there is a difference that exceeds a threshold (and optionally, if the difference exceeds the threshold within a certain minimum time), the torque fill module 106 calculates a torque amount (also referred to as "secondary torque") based on the difference and applies the secondary torque to the secondary shaft. The secondary torque can be calculated based on other factors and limited as described herein.

[0070] Figure 3 and 4 FIGS. and

[0070] illustrate embodiments of a dynamic fill torque system 110 and related methods for controlling torque in a vehicle system. Aspects of the related methods may be executed by one or more processors disposed in the vehicle, such as controller 46 or a combination of processors. For example, the method may be executed by ECU 42 in cooperation with MCU 44.

[0071] The dynamic fill torque system 110 includes an activation module 112 that determines conditions for initiating or activating the dynamic torque fill method. The activation module 112 compares various conditions with activation criteria 114 and deactivation criteria 116 and also maintains an activation timer 118.

[0072] The activation criteria 114 specify that the method is activated if it is detected that the driver has engaged the accelerator pedal, or if the system 110 detects a torque request from another vehicle system. For example, the method is activated if the pedal is depressed or moved a certain amount and / or if the rate of change of the pedal position exceeds a threshold rate. Based on the separation between the raw pedal measurement and the filtered measurement, the method can be activated if boolean operators and nested latches are used to increase pedal movement.

[0073] The deactivation criteria 116 are provided to ensure that dynamic torque fill can be provided without compromising other systems or functions of the vehicle. For example, a minimum state of charge (SOC) value of the battery pack 52 is defined, and if the SOC reaches or falls below this value, the method is turned off or stopped to conserve energy for chassis control and other systems.

[0074] The activation timer 118 can be used to set a time period. In one embodiment, the time period has a length (minimum time period) that is at least long enough to overcome any initial mismatches or torque conflicts. The time period can correspond to a timer set by another vehicle system (e.g., the "basic driver reset" timer used by the TARM algorithm).

[0075] The time period can be subject to a maximum time (i.e., the maximum amount of time for which dynamic torque fill is effective). In one embodiment, the maximum time period is set based on when the STR approaches the original axle torque request.

[0076] Upon activation and during a time period defined by an activation timer 118 (subject to minimum and maximum time limits), the dynamic fill torque calculation module 120 calculates a "dynamic fill torque", which is the amount of torque to be applied to the secondary shaft. The dynamic fill torque is based on a calculation of the difference between the actual main torque and the shaping torque request (STR).

[0077] In one embodiment, the module 120 detects any other appropriate torque strategies (e.g., for stability control) and takes these strategies into account when calculating the dynamic fill torque. This avoids interfering with such other strategies.

[0078] The module 120 calculates a "dynamic fill reference torque" 122 based on the main shaft torque request. In one embodiment, the dynamic fill reference torque 122 is a limited version of the main shaft torque request. For example, the module 120 uses the shaping torque request STR from the TARM 96 and reduces the magnitude of the shaping torque based on various factors. The dynamic fill reference torque can be proportional to the main shaft torque request curve.

[0079] The module 120 also calculates the actual torque or transmitted torque 124, which is an estimate of the torque transmitted to the main shaft. The actual torque 124 is estimated by measuring the torque applied to the main shaft. The actual torque 124 is added to the torque value corresponding to any secondary shaft torque request to calculate the total requested torque. The difference between the dynamic fill reference torque 122 and the actual torque 124 is equal to the dynamic fill torque. The dynamic fill torque can be a torque curve determined by limiting the dynamic fill reference torque 122 according to the difference (i.e., subtracting the actual torque 124 from the dynamic fill reference torque 122).

[0080] Control the fast response propulsion device (e.g., motor 30) according to the dynamic fill torque to provide a corresponding amount of secondary torque to the secondary shaft (e.g., secondary shaft 40). Ramp logic can be used to provide a smooth transition and maintain the continuity of the applied secondary torque. The secondary torque can be applied until the activation timer expires or until another condition requiring deactivation occurs.

[0081] Before and / or during the application of the secondary torque, the dynamic fill torque can be supplied to the dynamic torque fill limit module 126, which is configured to define maximum and / or minimum torque limits based on various parameters 128. These limits are used to constrain the dynamic fill torque. Examples of the parameters 128 for determining the limits include the state of charge of the battery pack, the estimated lateral acceleration, the calibration limits based on the driving mode, chassis control, and the capacity of the secondary shaft.

[0082] For example, the dynamic fill torque is limited by the maximum and minimum available countershaft torques. The available countershaft torque can be determined by detecting other torques applied to (or to be applied to) the countershaft and subtracting such torques from the available torque. Another torque can include strategic torque and can increase with charging and decrease with regeneration. Torque limits can also be applied based on the torque capabilities of the quick advance source to ensure filling only when needed and possible. The dynamic fill torque can be limited by multiplexing existing CAN signals to manage the yaw effect of the secondary torque during lateral loading.

[0083] The limited dynamic fill torque is then provided to the preemption module 130, which stops or blocks the dynamic torque fill so that the existing torque safety monitoring is not affected. The preemption module 130 dynamically calculates the limit to avoid a constant limit.

[0084] Figure 4 An embodiment of a preemption method 140 performed by the preemption module 130 is shown. The preemption method 140 includes various steps or stages represented by blocks 141 - 146.

[0085] The preemption method 140 is used to monitor the original driver request (e.g., the original axle torque request output from the arbitration module 92) and analyze the original driver request to ensure that the applied secondary torque does not exceed the original driver request within a calibration time period (e.g., 750 ms).

[0086] At block 141, the original driver request is monitored and the amount of time that the original driver request is non - zero ("original driver request time") is determined. Additionally, the amount of time that torque is applied to the main shaft ("main torque time") and the amount of time that secondary torque is applied ("secondary torque time") are determined. The main torque time is added to the secondary torque time to obtain a total time, which is compared with the original driver request time. Then it is determined whether the original driver request time exceeds the total time.

[0087] At block 142, if the original driver request time is less than or equal to the total time, the method 140 continues to monitor and determine the time amounts at block 141.

[0088] At block 143, if the original driver request time exceeds the total time, a timer corresponding to the calibration time period is started. At block 144, the timer is monitored. It is determined whether the timer has expired.

[0089] At block 145, the timer is continuously monitored until the timer expires.

[0090] At block 146, when the timer expires, the secondary torque is removed from the countershaft. The secondary torque can be removed gradually to avoid tripping any safety monitoring systems.

[0091] Refer again toFigure 3 , in one embodiment, a limited dynamic fill torque is provided to the dynamic fill rate limiting module 132, which is configured to define maximum and / or minimum torque rate limits (i.e., the rate of increase or decrease) based on various parameters 134. These limits are used to constrain the rate at which torque is applied to the secondary shaft. Examples of parameters used to determine the rate limits include an estimate of lateral acceleration, calibration limits based on driving mode, chassis control, and the rate of torque increase or decrease specified by the primary shaft torque request (e.g., a shaping torque request).

[0092] Note that the system 110 and method are not limited to the above description, as the system 110 can include any number of modules and method steps. For example, the modules 126, 130, and / or 132 may not be used or a subset of these modules may be used to calculate the dynamic fill torque.

[0093] Figure 5 Aspects of an embodiment of a computer system 240 that can execute various aspects of the embodiments described herein are shown. The computer system 240 includes at least one processing device 242, which generally includes one or more processors for executing various aspects of the image acquisition and analysis methods described herein.

[0094] The components of the computer system 240 include a processing device 242 (such as one or more processors or processing units), a memory 244, and a bus 246 that couples various system components, including the system memory 244, to the processing device 242. The system memory 244 can be a non-transitory computer-readable medium and can include various computer system-readable media. Such media can be any available media accessible by the processing device 242 and includes volatile and non-volatile media as well as removable and non-removable media.

[0095] For example, the system memory 244 includes non-volatile memory 248 such as a hard disk drive and can also include volatile memory 250 such as random access memory (RAM) and / or cache memory. The computer system 240 can also include other removable / non-removable, volatile / non-volatile computer system storage media.

[0096] The system memory 244 may include at least one program product having a set (i.e., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, the system memory 244 stores various program modules that typically perform the functions and / or methods described herein. Module 252 may be included for performing functions related to acquiring signals and data, and module 254 may be included for performing functions related to torque control as described herein. The system 240 is not limited thereto, as other modules may be included. As used herein, the term "module" refers to a processing circuit that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) executing one or more software or firmware programs, and memory, combinational logic circuitry, and / or other suitable components that provide the described functionality.

[0097] The processing device 242 may also communicate with one or more external devices 256, such as a keyboard, a pointing device, and / or any device that enables the processing device 242 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Communication with the various devices may be through input / output (I / O) interfaces 264 and 265.

[0098] The processing device 242 may also communicate with one or more networks 266 via a network adapter 268, such as a local area network (LAN), a general wide area network (WAN), a bus network, and / or a public network (e.g., the Internet). It should be understood that although not shown, other hardware and / or software components may be used in conjunction with the computer system 40. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc.

[0099] The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The term "or" means "and / or" unless the context clearly dictates otherwise. References throughout the specification to "one aspect" mean that a particular element (e.g., a feature, a structure, a step, or a property) described in connection with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. Additionally, it should be understood that the described elements may be combined in any suitable manner in the various aspects.

[0100] When an element such as a layer, a film, a region, or a substrate is referred to as being "on" another element, it may be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, no intervening elements are present.

[0101] Unless stated to the contrary herein, all test standards are the latest valid standards as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0102] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0103] Although the foregoing disclosure has been described with reference to exemplary embodiments, those of ordinary skill in the art will understand that various changes may be made and equivalents may be substituted for its elements without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Accordingly, it is intended that the disclosure not be limited to the particular embodiments disclosed, but that it will include all embodiments falling within its scope.

Claims

1. A system for controlling torque in a vehicle, comprising: A controller connected to a first propulsion system and a second propulsion system of the vehicle, the first propulsion system including an internal combustion engine configured to drive a main shaft, the second propulsion system including an electric motor configured to drive a secondary shaft, wherein the first propulsion system and the main shaft are mechanically independent of the second propulsion system and the secondary shaft, the controller being configured to execute a method including the following: Estimate a first torque amount applied to the main shaft in response to a main shaft torque request; Determine a difference between the first torque amount applied to the main shaft and the main shaft torque request; And Based on the difference exceeding a selected threshold, calculate a dynamic fill torque and apply a second torque amount to the secondary shaft through the electric motor according to the calculated dynamic fill torque.

2. The system according to claim 1, wherein The main shaft torque request is a shaped torque request determined based on a vehicle operation mode, and the dynamic fill torque is configured as a dynamic fill torque curve, and the dynamic fill torque curve is calculated by limiting the shaped torque request based on the difference.

3. The system according to claim 1, wherein The main shaft torque request is selected from a torque request provided by a control system and an expected torque request, the expected torque request being based on a driver input applied to an accelerator pedal, the driver input including at least one of a position of the accelerator pedal and a movement of the accelerator pedal, and the difference exists between the estimated first torque amount and the expected torque request.

4. The system according to claim 1, wherein, The controller is configured to start the method based on at least one activation criterion, the activation criterion including a minimum displacement of the pedal, a minimum magnitude of the first torque amount applied to the main shaft, and a minimum change rate of the first torque amount.

5. The system according to claim 1, wherein The controller is configured to limit the magnitude or rate of the second torque amount.

6. The system according to claim 5, wherein, The method includes limiting the second torque amount based on at least one of the following: a charge state of a battery assembly connected to the electric motor, a lateral acceleration, a vehicle operation mode, and a capacity of the secondary shaft.

7. The system according to claim 1, wherein The vehicle includes a battery assembly connected to the electric motor, and the controller is configured to stop applying the second torque amount based on the charge state of the battery assembly being lower than a charge state threshold.

8. The system according to claim 1, wherein The method includes calculating a total torque amount by summing the dynamic fill torque and the first torque amount, and eliminating the application of the second torque amount based on the main shaft torque request exceeding the total torque amount within a selected time period.

9. A method for controlling torque in a vehicle, comprising: Detect a main torque request for applying torque to a main shaft of the vehicle, the vehicle including a first propulsion system and a second propulsion system, the first propulsion system including an internal combustion engine configured to drive the main shaft, the second propulsion system including an electric motor configured to drive a secondary shaft, wherein the first propulsion system and the main shaft are mechanically independent of the second propulsion system and the secondary shaft; Estimate a first torque amount applied to the main shaft in response to the main shaft torque request; Determine a difference between the first torque amount applied to the main shaft and the main shaft torque request; And Based on the difference exceeding a selected threshold, calculate a dynamic fill torque and apply a second torque amount to the secondary shaft through the electric motor according to the calculated dynamic fill torque.

10. The method according to claim 9, wherein, The method is initiated based on at least one activation criterion, the activation criterion including a minimum displacement of the pedal, a minimum magnitude of a first torque amount applied to the spindle, and a minimum rate of change of the first torque amount.

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