Torque monitoring for multi-actuator vehicle systems

Abstract

A system for controlling torque in a vehicle includes a controller connected to a propulsion system having a plurality of independently controllable actuators configured to apply a combined torque. The controller is configured to execute a method that includes detecting a combined torque request indicative of a total requested torque to be applied to the vehicle, where the total requested torque is split and a portion of the total requested torque is assigned to each actuator. The method further includes determining a torque command for each actuator, estimating a total applied torque provided to the vehicle, and calculating an error value for each actuator based on a difference between the total applied torque and the total requested torque being greater than a first threshold, comparing each error value to a reference value, and determining a torque command for each actuator based on the difference between the total applied torque and the total requested torque being greater than the first threshold. And performing a remedial action based on the at least one error value exceeding the reference value.

Description

Technical Field

[0001] The present disclosure 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 vehicles, are characterized by various propulsion systems. Such propulsion systems can include multiple actuators. For example, a vehicle can have a combustion engine as a first actuator and one or more electric motors as additional actuators. In another example, a vehicle can have multiple electric motors driving different axles. Errors in the torque applied by each actuator can combine or stack up, resulting in the total torque exceeding a specified limit or not matching the driver's torque request. Summary of the Invention

[0003] In one exemplary embodiment, a system for controlling torque in a vehicle includes a controller connected to a propulsion system having multiple independently controllable actuators configured to apply a combined torque to propel the vehicle. The controller is configured to perform a method including monitoring the propulsion system and detecting a combined torque request indicating a total requested torque to be applied to the vehicle, where the total requested torque is divided and a portion of the total requested torque is allocated to each of the multiple actuators. The method further includes determining a torque command for each actuator, each torque command specifying the amount of torque to be allocated to the corresponding actuator, and during propulsion, estimating the total applied torque provided to the vehicle and comparing the total applied torque with the total requested torque. The method further includes: based on the difference between the total applied torque and the total requested torque being greater than a first threshold, calculating an error value for each actuator, the error value being the difference between the component amount of torque applied by the actuator and the allocated amount of torque, comparing each error value with a reference value, and performing a remedial action based on at least one error value exceeding the reference value.

[0004] In addition to one or more of the features described herein, the remedial action includes disabling at least one actuator.

[0005] In addition to one or more of the features described herein, comparing each error value includes determining a maximum error value, and performing the remedial action includes disabling the actuator associated with the maximum error value based on the maximum error value exceeding a second threshold.

[0006] In addition to one or more of the features described herein, comparing each error value with a corresponding error threshold, and performing the remedial action includes disabling the actuator having an error value exceeding the corresponding error threshold.

[0007] In addition to one or more features described herein, the method includes re - estimating the total applied torque and comparing the re - estimated total applied torque to a first threshold.

[0008] In addition to one or more features described herein, the method includes disabling at least one additional actuator based on a difference between the re - estimated total applied torque and the total requested torque being greater than a first threshold.

[0009] In addition to one or more features described herein, the method includes continuing to apply torque by one or more remaining active actuators based on the re - estimated total applied torque being less than or equal to the first threshold.

[0010] In addition to one or more features described herein, the plurality of actuators includes a first actuator configured to drive a main shaft and a second actuator configured to drive a secondary shaft.

[0011] In addition to one or more features described herein, the first actuator includes a combustion engine and the second actuator includes an electric motor.

[0012] In another exemplary embodiment, a method of controlling torque in a vehicle includes monitoring a propulsion system having a plurality of independently controllable actuators configured to apply a combined torque for propelling the vehicle, and detecting a combined torque request that indicates a total requested torque to be applied to the vehicle, where the total requested torque is divided and a portion of the total requested torque is allocated to each of the plurality of actuators. The method also includes determining a torque command for each actuator, each torque command specifying the amount of allocated torque to be applied to the corresponding actuator, and during propulsion, estimating the total applied torque provided to the vehicle and comparing the total applied torque to the total requested torque. The method also includes calculating, based on a difference between the total applied torque and the total requested torque being greater than a first threshold, an error value for each actuator, the error value being a difference between the component amount of torque applied by the actuator and the allocated amount of torque, comparing each error value to a reference value, and performing a remedial action based on at least one error value exceeding the reference value.

[0013] In addition to one or more features described herein, the remedial action includes disabling at least one actuator.

[0014] In addition to one or more features described herein, comparing each error value includes determining a maximum error value, and performing the remedial action includes disabling the actuator associated with the maximum error value based on the maximum error value exceeding a second threshold.

[0015] In addition to one or more features described herein, each error value is compared to a corresponding error threshold, and performing a remedial action includes disabling an actuator having an error value that exceeds the corresponding error threshold.

[0016] In addition to one or more features described herein, the method includes re - estimating a total applied torque and comparing the re - estimated total applied torque to a first threshold.

[0017] In addition to one or more features described herein, the method includes disabling at least one additional actuator based on a difference between the re - estimated total amount of applied torque and the total requested torque being greater than a first threshold.

[0018] In addition to one or more features described herein, the method includes continuing to apply torque by one or more remaining active actuators based on the re - estimated total amount of applied torque being less than or equal to the first threshold.

[0019] In yet another exemplary embodiment, a vehicle system includes a propulsion system and a controller. The propulsion system has a plurality of independently controllable actuators configured to apply a combined torque to propel the vehicle. The controller is configured to perform a method that includes monitoring the propulsion system and detecting a combined torque request that indicates a total requested torque to be applied to the vehicle, where the total requested torque is divided and a portion of the total requested torque is allocated to each of the plurality of actuators. The method also includes determining a torque command for each actuator, where each torque command specifies an amount of the allocated torque to be applied to the corresponding actuator, and during propulsion, estimating the total applied torque provided to the vehicle and comparing the total applied torque to the total requested torque. The method also includes calculating, based on a difference between the total applied torque and the total requested torque being greater than a first threshold, an error value for each actuator, where the error value is a difference between a component amount of torque applied by the actuator and the allocated amount of torque, comparing each error value to a reference value, and performing a remedial action based on at least one error value exceeding the reference value.

[0020] In addition to one or more features described herein, the remedial action includes disabling at least one actuator.

[0021] In addition to one or more features described herein, comparing each error value includes determining a maximum error value, and performing a remedial action includes disabling the actuator associated with the maximum error value based on the maximum error value exceeding a second threshold.

[0022] In addition to one or more features described herein, each error value is compared to a corresponding error threshold, and performing a remedial action includes disabling an actuator having an error value that exceeds the corresponding error threshold.

[0023] These and other features and advantages of the present disclosure will be apparent from the following detailed description when taken 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 2A and Figure 2B illustrates a block diagram depicting aspects of a method for controlling torque according to an exemplary embodiment;

[0027] Figure 3 depicts an example of an operating state achievable using Figure 2A and 2B of the method; and

[0028] Figure 4 depicts a computer system according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] 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 throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0030] According to an exemplary embodiment, methods, devices, and systems are provided for monitoring vehicle propulsion in a vehicle having a plurality of independently controllable actuators. An "actuator" is any device or system that can be controlled to apply torque to a vehicle, such as a combustion engine or an electric motor. For example, the vehicle can be a hybrid vehicle or an electric vehicle having an independent electric motor. In another example, the vehicle includes a primary actuator in the form of a combustion engine and a secondary actuator in the form of an electric motor for supplementary propulsion.

[0031] Embodiments of the method include monitoring a vehicle propulsion system during vehicle operation, which includes detecting a torque request (e.g., from a driver's engagement of an accelerator pedal, or from an autonomous control system). The torque request (also referred to as the "combined torque request") specifies the total amount of torque requested for propulsion. The combined torque request is divided among a plurality of independently controllable actuators, and commands are sent to each actuator to allocate a portion of the total requested torque.

[0032] The controller detects the amount of torque (“component torque”) applied by each actuator and combines the component torques to calculate the total applied torque. The total applied torque is compared with the total requested torque to calculate the difference therebetween. If the difference exceeds a first threshold difference, the actuators are individually evaluated to determine the difference (“error” or “error value”) between the actual torque amount applied by the actuator and the commanded or allocated torque. If, for example, the maximum error value exceeds a second threshold, or if the error value associated with an actuator exceeds a corresponding threshold (e.g., a threshold specific to that actuator), a remedial action is performed. The remedial action may include disabling one or more actuators to keep the total applied torque within the total requested torque. In one embodiment, the remedial action includes disabling one or more actuators and allowing at least one actuator to remain active to allow the vehicle to move off the road or to a desired location.

[0033] The embodiments described herein present numerous advantages and technical effects. The embodiments provide improvements in diagnostics, thereby allowing for a more refined identification of errors in a propulsion system. Additionally, the embodiments provide various remedial actions not allowed in current multi-actuator propulsion systems. For example, existing diagnostic systems for multi-actuator vehicles can evaluate errors in propulsion, but cannot evaluate the individual actuator error contributions. The embodiments address this challenge by providing individual actuator evaluations and also allow for maintaining a level of propulsion by operating a subset of the actuators.

[0034] The embodiments are not limited to use with any particular vehicle and can be applicable in a variety of environments. For example, the embodiments can be used with automobiles, trucks, construction equipment, farm equipment, automated factory equipment, and / or any other device or system having multiple propulsion systems.

[0035] Figure 1 An embodiment of a motor vehicle 10 is shown, the motor vehicle 10 including a body 12 that at least partially defines an occupant compartment 14. The body 12 also supports various vehicle subsystems, including a propulsion system 16, and other subsystems for supporting the functions of the propulsion system 16 and other vehicle components, such as a braking subsystem, a suspension system, a steering subsystem, and, if the vehicle is a hybrid electric vehicle, a fuel injection subsystem, an exhaust subsystem, etc.

[0036] In one embodiment, the propulsion system 16 forms at least a part of a multi-actuator powertrain system that includes at least two independent torque generating devices (referred to herein as “actuators”). The actuators are independently controllable such that each actuator can apply a selected amount of torque to an axle based on a combined torque request.

[0037] For example, propulsion system 16 includes a first actuator 18 in the form of a combustion engine 18 for applying torque, and other components for supporting engine operation, such as a cooling system 20. Engine 18 is connected to a driveline 22, which is used to control the transfer of torque from engine 18 to a rear drive shaft 24, which is also referred to as a main shaft 24. Main shaft 24 is connected to rear wheels 26. Engine 18 may be coupled to rear drive shaft 24 as shown, or alternatively coupled to a front drive shaft 34 (in which case, front drive shaft 34 may be considered the main shaft).

[0038] Propulsion system 16 also includes an electric drive system that is configured to supply additional torque (e.g., in a high-performance mode), and may also be configured to propel vehicle 10 alone (e.g., if combustion engine 18 fails). For example, vehicle 10 includes at least one electric motor 28 and at least one inverter 30. Inverter 30 (e.g., a traction power inverter unit or TPIM) converts direct current (DC) power from a high-voltage (HV) battery pack 52 into polyphase (e.g., two-phase, three-phase, six-phase, etc.) alternating current (AC) power to drive motor 28. Motor 28 is connected to a gearbox 32 for controlling the transfer of torque from motor 28 to drive shaft 34 (also referred to as a secondary shaft 34) and front wheels 36.

[0039] Propulsion system 16 is not limited to Figure 1 the configuration, number, or type of actuators shown. Any number of actuators may be connected to each shaft 24, 34. For example, vehicle 10 may be configured as a hybrid vehicle that includes a front combustion engine and an electric motor positioned toward the front of vehicle 10. In another example, vehicle 10 is an all-electric vehicle having one electric motor or multiple electric motors (e.g., an electric motor for each shaft, multiple electric motors on a shaft, or an electric motor for each wheel).

[0040] including one or more processing devices to control the operation of propulsion system 16. The one or more processing devices are configured to control the torque output of propulsion system 16 based on a driver torque request, which may be provided via an accelerator pedal or throttle pedal 38.

[0041] In one embodiment, an engine control unit (ECU) 40 is configured to receive the torque request and control engine 20, and a motor control unit (MCU) 42 is configured to control the torque applied by motor 30. A processing device referred to as a controller 44 may be provided to process the torque request and coordinate the control of the engine and motor as described herein. For example, controller 46 is configured to provide an electric all-wheel drive (AWD) capability, which allows torque to be selectively distributed between the axles. Note that the embodiments are not limited to this, and any number of processing devices or combinations thereof may be used.

[0042] The motor 28 and 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).

[0043] In one embodiment, the battery system 50 includes a battery assembly such as the battery pack 52. The battery pack 52 includes a plurality of battery modules 54, where each battery module 54 includes a plurality of individual battery 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.

[0044] The vehicle 10 also includes a computer system 60, which includes one or more processing devices 62 and a user interface 64. The computer system 60 may communicate with the controller 44 and / or other processors, e.g., to provide commands thereto in response to user input (e.g., a torque command). The various processing devices, modules, and units may communicate with each other via a communication device or system such as a controller area network (CAN) or a transmission control protocol (TCP) bus. The various processing devices, modules, and units may communicate with each other via other forms of communication such as Ethernet and wireless communication.

[0045] Figure 2A and 2B An embodiment of a method 80 for controlling propulsion in a vehicle is shown. Aspects of the method 80 may be performed by one or more processors disposed in the vehicle 10. For illustrative purposes, the method 80 is described as being performed by the controller 44 (optionally in coordination with the ECU 40 and the MCU 42).

[0046] Note that the method 80 is not limited thereto and may be performed by any suitable processing device or system or combination of processing devices. Additionally, the method 80 is not limited to use with the vehicle 10, as the method 80 may be performed in conjunction with any suitable vehicle or machine having a propulsion system with independently controllable actuators.

[0047] The method 80 includes a plurality of steps or stages represented by blocks 81 - 95. The method 80 is not limited to the number or order of the steps therein, as some of the steps represented by blocks 81 - 95 may be performed in an order different from the order described below, or fewer than all of the steps may be performed.

[0048] At block 81, the method 80 begins by initiating monitoring of a multi - actuator propulsion system such as the propulsion system 16. Such monitoring is also referred to as multi - axis monitoring or multi - actuator monitoring.

[0049] At block 82, a torque request is detected, referred to as a combined torque request. The combined torque request can be determined by controller 44 or an existing control system (e.g., an AWD control system). For example, a user (driver) engages pedal 38, and the pedal position and / or movement is converted into a longitudinal torque value, referred to as the total requested torque. The longitudinal torque value can be determined via the pedal position and other parameters (e.g., vehicle speed, driveline losses, transmission state, etc.). The longitudinal torque value can take into account other factors, such as other torque requests not primarily for longitudinal propulsion purposes (e.g., from chassis control interventions such as stability control).

[0050] At block 83, when determining the total requested torque, controller 44 or the AWD control system determines how the torque should be distributed among n actuators (n = 2 or more). In one embodiment, the total requested torque is divided into sub-torque requests (“torque commands”) sent to the n actuators.

[0051] For example, an engine torque command indicates that engine 18 supplies a portion of the total requested torque to main shaft 24, and a motor torque command instructs electric motor 28 to provide the remaining torque to secondary shaft 34.

[0052] At block 84, controller 44 receives the individual torque commands and sums the torque commands to determine the total amount of requested torque (referred to as the “superimposed requested torque value”). The superimposed requested torque value is compared to the total requested torque, and the difference between them is calculated. Controller 44 determines whether the difference is less than or equal to a selected threshold difference.

[0053] At block 85, if the difference exceeds the selected threshold difference, controller 44 determines that the torque distribution is unsafe.

[0054] At block 86, controller 44 instructs the AWD control system to re-distribute the total requested torque, e.g., by reducing the degrees of freedom of the split (e.g., reducing the allowable torque to secondary shaft 34). The number of actuators available for applying torque can also be reduced.

[0055] At block 87, if the difference between the superimposed torque request and the total requested torque is less than or equal to the selected threshold difference, torque commands are sent to each actuator. For example, a first torque command is sent to ECU 40 to apply a first amount of torque to main shaft 24, and a second torque command is sent to MCU 42 to apply a second amount of torque to secondary shaft 34.

[0056] At block 88, the actuators (e.g., engine 18 and electric motor 28) and the propulsion system (e.g., propulsion system 16) are monitored, and the component amounts of torque applied by each actuator are measured or estimated. The total amount of torque applied by all actuators ("superimposed torque") is compared with the total requested torque. The difference between the superimposed torque and the total requested torque is calculated (referred to as "superimposed error").

[0057] At block 89, the superimposed error is compared with a selected threshold or metric ("first threshold"). If the superimposed error is less than or equal to the first threshold, method 80 loops back to block 81.

[0058] If the superimposed error exceeds the first threshold, method 80 continues to individually evaluate each actuator and perform a remedial action (see Figure 2B ). The remedial action may include disabling one or more actuators. The remedial action may be performed to remove one or more actuators to make the total applied torque consistent with the total requested torque.

[0059] In some cases, the remedial action may include disabling at least one actuator while keeping at least one other actuator active to allow the vehicle to be removed from the road and / or driven to another location at reduced power.

[0060] For example, when the controller 44 detects that the superimposed error associated with the engine 18 and the motor 28 exceeds the metric, but no single actuator will exceed the metric, the remedial action may be that only one of the actuators (e.g., the motor 28) is active. The active actuator is controlled to provide sufficient propulsion force (which may be limited). This remedial action is called single-axle limp-home (SALH), which allows the vehicle 10 to maintain propulsion while still eliminating the error superposition that may cause system-level hazards.

[0061] Refer to Figure 2B , at block 90a, the first amount of applied torque from the first actuator (e.g., engine 18) is measured or estimated and compared with the corresponding torque command. The difference between the applied torque and the commanded torque is calculated ("actuator error").

[0062] At block 91a, the actuator error is compared with a metric in the form of a selected threshold ("reference value"), and it is determined whether the actuator error exceeds the reference value. Note that for each actuator, the selected threshold or reference value may be the same or different.

[0063] At block 92a, if the actuator error exceeds the reference value, the first actuator is disabled.

[0064] At block 90b, the amount of second applied torque from a second actuator (e.g., motor 28) is measured or estimated and compared to a corresponding torque command. The difference between the applied torque and the commanded torque (i.e., the actuator error) is calculated.

[0065] At block 91b, the actuator error is compared to a reference value (a selected threshold or other metric), and it is determined whether the actuator error exceeds the reference value.

[0066] At block 92b, if the actuator error exceeds the reference value, the second actuator is disabled.

[0067] For each additional actuator, a similar process is performed, represented by blocks 90n, 91n, and 92n.

[0068] At block 93, if no actuator error exceeds its respective reference value or metric, the actuator error with the largest magnitude is determined, and the corresponding actuator is identified.

[0069] At block 94, the actuator error with the largest magnitude is compared to a metric in the form of a second threshold. If the actuator error is greater than the second threshold, the identified actuator is disabled.

[0070] For example, if motor 28 has an actuator error greater than that of other actuators (including engine 18 and any other existing actuators, such as additional electric motors), motor 28 is disabled. Similarly, if the actuator error of engine 18 is the largest, engine 18 is disabled (if sufficient power is available, vehicle 10 can use electric motor 28 to limp home).

[0071] At block 95, one or more additional actuators may be disabled to maintain an effective configuration. For example, if the identified actuator and another actuator are mechanically coupled to the same shaft, both actuators may be disabled. "Disable" may refer to turning off the actuator, cutting power to the actuator, and / or mechanically decoupling the actuator from the shaft.

[0072] If removing one of the actuators brings the superposition error back below the metric, a remedial action may be selected to allow the vehicle to enter a single-axle limp home. If the errors of all actuators are large enough to independently violate the metric, the remedy may include a full propulsion shutdown.

[0073] In one embodiment, method 80 loops back to block 81, where blocks 82 - 85 are repeated without disabling any actuators. For example, the requested torque is determined again (or it is assumed that the requested torque remains the same), and the various calculations are repeated using a new configuration in which the disabled actuator(s) are excluded from the calculations and subsequent actuator control.

[0074] It should be understood that the discussion herein is in the torque domain and, more specifically, in the driveline torque domain. However, vehicle monitoring can initially occur in the acceleration domain and later be converted to the driveline torque domain.

[0075] Figure 3 is a table depicting examples of operating states that can be achieved using the embodiments described herein as compared to existing torque control systems. In this example, the vehicle includes two independent actuators, referred to as actuator “A1” and actuator “A2”. For example, actuator A1 is the combustion engine 18 and actuator A2 is the electric motor 28.

[0076] The table shows various error conditions and operating states for actuators A1 and A2. The error condition can be an “under metric” condition (denoted as “U”), where the actuator error is less than or equal to the error threshold or otherwise meets one or more selected metrics. An “above metric” condition (denoted as “A”) is a condition where the actuator error is greater than the error threshold or otherwise violates one or more selected metrics.

[0077] The operating states include a shutdown state (“SD”), where all actuators are disabled, and a single driveline limp-home state (“SALH”). The column labeled “E” represents the operating state of the vehicle when controlled using the existing system, and the column labeled “MAC” represents the operating state when multi-actuator control is performed in accordance with the embodiments described herein.

[0078] Each row indicates the error conditions and operating states for different scenarios (S1 - S5). In scenario S1, no error is detected. In scenario S2, no individual actuator is above metric, but the combination of errors (“sum”) is above the threshold or violates one or more metrics. In scenarios S3 and S4, one actuator is above metric. In scenario S5, both actuators are above metric.

[0079] As shown, if no error is detected, then all actuator errors and the sum of the actuator errors (superimposed error) are below the selected metric and the vehicle operates normally. If no individual actuator error is above metric, but the superimposed error is above metric, then the existing torque system requires a full shutdown. However, the method described herein allows one of the actuators to apply a certain amount of torque (single driveline limp-home or SALH).

[0080] If the superimposed error is above metric, but one of the actuators is below metric, then the method described herein allows SALH. In contrast, the existing system requires a full shutdown.

[0081] Figure 4Aspects of an embodiment of a computer system 140 are shown that can perform aspects of the embodiments described herein. The computer system 140 includes at least one processing device 142, which generally includes one or more processors for performing aspects of the image acquisition and analysis methods described herein.

[0082] Components of the computer system 140 include a processing device 142 (such as one or more processors or processing units), a memory 144, and a bus 146 that couples various system components including the system memory 144 to the processing device 142. The system memory 144 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 142 and includes volatile and non-volatile media as well as removable and non-removable media.

[0083] For example, the system memory 144 includes a non-volatile memory 148 such as a hard disk drive, and can also include a volatile memory 150 such as random access memory (RAM) and / or cache memory. The computer system 140 can also include other removable / non-removable, volatile / non-volatile computer system storage media.

[0084] The system memory 144 can 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 144 stores various program modules that generally perform the functions and / or methods of the embodiments described herein. Modules 152 can be included for performing functions related to acquiring signals and data, and modules 154 can be included for performing functions related to torque control as discussed herein. The system 140 is not limited thereto as other modules can be included. As used herein, the term "module" refers to a processing circuit that can include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or grouped) that executes one or more software or firmware programs, memory, combinational logic circuitry, and / or other suitable components that provide the described functionality.

[0085] The processing device 142 can also communicate with one or more external devices 156, such as a keyboard, pointing device, and / or any device that enables the processing device 142 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Communication with the various devices can occur via input / output (I / O) interfaces 164 and 165.

[0086] The processing device 142 can also communicate with one or more networks 166, 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), via a network adapter 168. 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.

[0087] 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. Unless the context clearly dictates otherwise, the term "or" means "and / or". References to "aspect" throughout the specification mean that a particular element (e.g., a feature, a structure, a step, or a characteristic) 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.

[0088] When an element such as a layer, a film, a region, or a substrate is referred to as being "on" another element, it can 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.

[0089] Unless otherwise stated herein, all test standards are the latest standards in effect 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 standards appear.

[0090] Unless otherwise defined, the 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.

[0091] Although the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can be substituted for its elements without departing from its scope. Additionally, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from its basic scope. Accordingly, it is intended that the disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A system for controlling torque in a vehicle, comprising: A controller connected to a propulsion system having a plurality of independently controllable actuators configured to apply a combined torque for propelling the vehicle, the controller being configured to perform a method comprising: Monitoring the propulsion system and detecting a combined torque request indicative of a total requested torque to be applied to the vehicle, wherein the total requested torque is divided and a portion of the total requested torque is allocated to each of the plurality of actuators; Determining a torque command for each actuator, each torque command specifying the amount of torque of the allocated amount to be applied to the corresponding actuator; During propulsion, estimating the total applied torque provided to the vehicle and comparing the total applied torque with the total requested torque; Based on the difference between the total applied torque and the total requested torque being greater than a first threshold, calculating an error value for each actuator, the error value being the difference between the component amount of torque applied by the actuator and the allocated amount of torque; and Comparing each error value with a reference value and performing a remedial action based on at least one error value exceeding the reference value.

2. The system according to claim 1, wherein the remedial action includes disabling at least one actuator, comparing each error value includes determining a maximum error value, and performing the remedial action includes disabling the actuator associated with the maximum error value based on the maximum error value exceeding a second threshold.

3. The system according to claim 1, wherein the remedial action includes disabling at least one actuator, comparing each error value with a corresponding error threshold, and performing the remedial action includes disabling the actuator having an error value exceeding the corresponding error threshold.

4. The system according to claim 2, wherein the remedial action includes disabling at least one actuator, and the method includes re - estimating the total applied torque and comparing the re - estimated total applied torque with the first threshold.

5. The system according to claim 4, wherein the method includes disabling at least one additional actuator based on the difference between the total amount of the re - estimated applied torque and the total requested torque being greater than the first threshold.

6. The system according to claim 4, wherein the method includes continuing to apply torque by one or more remaining active actuators based on the total amount of the re - estimated applied torque being less than or equal to the first threshold.

7. The system according to claim 1, wherein the plurality of actuators includes a first actuator configured to drive a main shaft and a second actuator configured to drive a secondary shaft.

8. The system according to claim 7, wherein the first actuator includes a combustion engine and the second actuator includes an electric motor.

9. A method of controlling torque in a vehicle, comprising: Monitoring a propulsion system having a plurality of independently controllable actuators configured to apply a combined torque for propelling the vehicle; Detecting a combined torque request indicative of a total requested torque to be applied to the vehicle, wherein the total requested torque is divided and a portion of the total requested torque is allocated to each of the plurality of actuators; Determine a torque command for each actuator, each torque command specifying an allocated amount of torque to be applied to a corresponding actuator; During propulsion, estimate a total applied torque provided to the vehicle and compare the total applied torque with a total requested torque; Based on the difference between the total applied torque and the total requested torque being greater than a first threshold, calculate an error value for each actuator, the error value being a difference between a component amount of torque applied by the actuator and the allocated amount of torque; And Compare each error value with a reference value and perform a remedial action based on at least one error value exceeding the reference value.

10. The method according to claim 9, wherein the remedial action includes disabling at least one actuator, and the method includes at least one of the following: Determine a maximum error value and disable the actuator associated with the maximum error value based on the maximum error value exceeding a second threshold; and Compare each error value with a corresponding error threshold and disable the actuator having an error value exceeding the corresponding error threshold.

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