Monitoring state of health of battery resistance

Abstract

A method for determining a state of health (SOH) of an electrical connection in a steering system, the method comprising using a processor configured to execute instructions: receiving an input indicative of the SOH of the electrical connection, the input comprising a resistance associated with the electrical connection, and the SOH corresponds to at least one of an accumulated health (AH) of the electrical connection and a remaining available life (RUL) of the electrical connection; calculating a first SOH value based on the received input and a usage associated with the vehicle; calculating a second SOH value based on the received input and a behavior associated with the vehicle; calculating a third SOH value based on the first SOH value and the second SOH value, the third SOH value being an indicator of the AH or the RUL of the electrical connection; and performing at least one action based on the third SOH value.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 542,451, filed on October 4, 2023. The entire disclosures of the above-referenced applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to systems and methods for monitoring the health of a connection between a power source and an electronic power steering (EPS) system. Background Art

[0004] Vehicles (such as cars, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable forms of transportation) typically include a steering system, such as an electronic power steering (EPS) system, a steer-by-wire (SbW) steering system, a hydraulic steering system, or other suitable steering system. The steering system of such a vehicle typically controls various aspects of the vehicle's steering, including providing steering assistance to the operator of the vehicle, controlling the steering wheel of the vehicle, etc. Summary of the invention

[0005] The present disclosure generally relates to determining the health of electrical connections in a steering system of a vehicle.

[0006] A method for determining a state of health (SOH) of an electrical connection in a steering system of a vehicle, comprising using a processor configured to execute instructions: receiving an input indicating the SOH of the electrical connection, the input comprising a resistance associated with the electrical connection, and the SOH corresponding to at least one of an accumulated health (AH) of the electrical connection and a remaining useful life (RUL) of the electrical connection; calculating a first SOH value based on the received input and usage associated with the vehicle; calculating a second SOH value based on the received input and behavior associated with the vehicle; calculating a third SOH value based on the first SOH value and the second SOH value, the third SOH value being an indicator of the AH or the RUL of the electrical connection; and performing at least one action based on the third SOH value.

[0007] Other aspects of the disclosed embodiments include systems configured to perform the steps and functions of the described methods.

[0008] These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, in accordance with conventional practice, the various features of the drawings are not drawn to scale. Instead, the sizes of the various features are arbitrarily enlarged or reduced for clarity.

[0010] Figure 1A A vehicle according to the principles of the present disclosure is generally illustrated.

[0011] Figure 1B A controller according to the principles of the present disclosure is generally illustrated.

[0012] Figure 2 An example electronic power steering (EPS) system according to the principles of the present disclosure is generally schematically illustrated.

[0013] Figure 3 Example degradation of an electrical connection during its useful life is generally illustrated.

[0014] Figure 4 Examples of accumulated health (AH) and remaining useful life (RUL) calculated using usage-based techniques and behavior-based techniques are generally illustrated.

[0015] FIG. 5A to FIG. 5E Various example AH calculation methods according to the principles of the present disclosure are generally illustrated.

[0016] Figure 6 is a flow chart generally illustrating the steps of an example method for calculating AH and / or RUL according to the principles of the present disclosure. DETAILED DESCRIPTION

[0017] The following discussion is directed to various embodiments of the present disclosure. Although one or more of these embodiments may be preferred, the disclosed embodiments should not be interpreted or otherwise used to limit the scope of the present disclosure (including the claims). In addition, it will be understood by those skilled in the art that the following description has a wide range of applications, and the discussion of any embodiment is only meant to illustrate the embodiment, and is not intended to imply that the scope of the present disclosure (including the claims) is limited to the embodiment.

[0018] As described, a vehicle (such as a car, truck, sport utility vehicle, crossover, minivan, boat, aircraft, all-terrain vehicle, recreational vehicle, or other suitable form of transportation) typically includes a steering system, such as an electronic power steering (EPS) system, a steer-by-wire (SbW) steering system, a hydraulic steering system, or other suitable steering system. The steering system of such a vehicle typically controls various aspects of the vehicle's steering, including providing steering assistance to the operator of the vehicle, controlling the vehicle's steering wheel, etc. Although described herein with respect to a vehicle, the principles of the present disclosure may also be implemented in other types of transportation or non-transportation devices that include a steering system.

[0019] Vehicles typically include one or more motors, such as electric motors configured to control various aspects of the vehicle's steering system. High-power electrical harnesses and connectors can supply electrical power from the vehicle's electrical system (e.g., a battery and / or an alternator) to the motor controller of one or more motors of the steering system. During the life of the vehicle, the high-power connection properties may deteriorate, resulting in an eventual lack of sufficient input power to deliver the desired electromechanical output power to provide steering assistance or steering angle functions. This degradation can be observed as an effective increase in the resistance of the power connector or harness. When attempting to deliver this electromechanical output power, the power current draw through the increased resistance of the high-power connection or harness will result in a large voltage drop between the vehicle power supply and the motor controller, which can result in the total voltage at the motor controller input being low enough to result in a "shutdown" or "fall from an operating state", which can result in a loss of functionality, such as a loss of assistance in an EPS system and / or a loss of angle control in an advanced driver assistance system (ADAS) or SbW system. In some examples, even if the motor controller input is not shut down, the reduced available power may result in lower torque assistance, hysteresis response, poor feedback, reduced angle control, and overall reduced steering performance.

[0020] In some embodiments, it is desirable to detect the degradation condition and / or limit the electromechanical output power command based on detecting the degradation condition in order to reduce the required input power and prevent loss of functionality of the steering system, such as loss of assistance in an EPS system or loss of angle control in an ADAS or SbW system. Although performance may be reduced, this may be preferable to alternatives, which may include complete loss of assistance or angle control functionality.

[0021] Some systems may implement techniques for determining degradation of the input power connection (or harness) using available signals within existing control modules and software. An example system for determining power connection degradation is described in more detail in U.S. Patent Application No. 17 / 733,434, filed on April 29, 2022, the entire contents of which are incorporated herein by reference. In this example, electric power is applied to the motor phase and the response is measured. The applied power is V*I, where V and I are the vector of the applied motor voltage and the vector of the motor current, respectively. In some examples, the applied electric power is selected to produce zero motor torque. For example, for an EPS system, a sinusoidal, non-torque-producing current is applied to the motor phase. For ADAS and SbW systems, a sinusoidal, non-torque-producing or torque-producing current may be applied. The measurement of the response (e.g., a voltage measured at the control module input, such as a bridge voltage) indicates degradation and SOH of the input power connection.

[0022] In some examples, determining the SOH of a connection may include determining the cumulative health (AH), the remaining usable life (RUL) of the connection, or other SOH predictors. For example, the AH may correspond to a percentage, such as a percentage of remaining life or usage, and the RUL may correspond to a time period, such as a remaining life time period. The determination of the AH and RUL may be performed based on usage (e.g., based on a usage-based model configured to calculate the AH and / or RUL based on usage) or behavior (e.g., based on one or more measurements of driver behavior, such as sensor and / or derived signal measurements, vehicle behavior and / or characteristics, etc.). For example, usage may be calculated based on miles driven, hours of operation, current detected, current used, vibration, time at temperature, etc. As used herein, "SOH" may be collectively referred to as AH, RUL, and / or other SOH indicators.

[0023] Determining AH and RUL based solely on usage or behavior may not provide an accurate SOH for a connection. For example, the closer to the end of the life of a connection, the more critical it may be to provide accurate AH and RUL. However, for usage-based calculations, near the end of the life, unmeasurable or unpredictable factors (such as unmeasurable environmental factors) may lead to significantly different results under the same usage conditions. In contrast, behavior-based calculations that use measurement data to estimate health status may be less accurate early in the life of a connection and more accurate near the end of the life of the connection. For example, the measurements used in behavior-based calculations may have a non-linear relationship with connection degradation and therefore only provide accurate results near the end of the life of the connection.

[0024] Therefore, the SOH monitoring system and method according to the present disclosure are configured to calculate AH and RUL using a combination of usage-based techniques and behavior-based techniques. Two separate time periods are used to demonstrate the difference between the results of usage-based techniques and behavior-based techniques. In one example, during a first (e.g., "early life") period of the life of a connection, a usage-based technique may be applied to calculate AH and / or RUL. Conversely, during a second (e.g., "late life") period of the life of a connection, a behavior-based technique may be applied to calculate AH / RUL. In other words, usage-based techniques are used to calculate AH / RUL in the first period when the behavior-based technique cannot yet detect connection degradation, and behavior-based techniques are used to calculate AH / RUL in the second period when the usage-based technique is less accurate. Various techniques for combining usage-based techniques and behavior-based calculation techniques for AH and RUL are described herein. Although described with respect to two time periods / life periods of a connection, in some examples, more than two time periods may be used under different mechanisms, weightings, etc., depending on different failure modes associated with different factors during the life period of the connection.

[0025] Furthermore, although described with respect to steering systems, the principles of the present disclosure may be implemented in other types of vehicular or non-vehicular systems that include motors and actuators (eg, windshield wiper systems, propulsion systems, window controls, etc.).

[0026] Figure 1A A vehicle 10 in accordance with the principles of the present disclosure is generally illustrated. The vehicle 10 may include any suitable vehicle, such as a car, a truck, a sport utility vehicle, a minivan, a crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. Although the vehicle 10 is illustrated as a passenger vehicle having wheels and for use on roads, the principles of the present disclosure may be applied to other vehicles, such as airplanes, boats, trains, drones, or other suitable vehicles.

[0027] The vehicle 10 includes a vehicle body 12 and a hood 14. A passenger compartment 18 is at least partially defined by the vehicle body 12. Another portion of the vehicle body 12 defines an engine compartment 20. The hood 14 may be movably attached to a portion of the vehicle body 12 such that when the hood 14 is in a first position or an open position, the hood 14 provides access to the engine compartment 20, and when the hood 14 is in a second position or a closed position, the hood 14 covers the engine compartment 20. In some embodiments, the engine compartment 20 may be disposed at the rear of the vehicle 10, rather than as is typically illustrated.

[0028] The passenger compartment 18 may be disposed rearward of the engine compartment 20, but in embodiments where the engine compartment 20 is disposed at the rear of the vehicle 10, the passenger compartment 18 may be disposed forward of the engine compartment 20. The vehicle 10 may include any suitable propulsion system including an internal combustion engine, one or more electric motors (e.g., for an electric vehicle), one or more fuel cells, a hybrid propulsion system including a combination of an internal combustion engine and one or more electric motors (e.g., for a hybrid vehicle), and / or any other suitable propulsion system.

[0029] In some embodiments, the vehicle 10 may include a petrol or gasoline fuel engine, such as a spark ignition engine. In some embodiments, the vehicle 10 may include a diesel fuel engine, such as a compression ignition engine. The engine compartment 20 accommodates and / or encloses at least some components of the propulsion system of the vehicle 10. Additionally or alternatively, propulsion controls (such as accelerator actuators (e.g., accelerator pedals), brake actuators (e.g., brake pedals), steering wheels, and other such components) are disposed in the passenger compartment 18 of the vehicle 10. The propulsion controls may be actuated or controlled by an operator of the vehicle 10, and the propulsion controls may be directly connected to corresponding components of the propulsion system, such as throttles, brakes, vehicle axles, vehicle transmissions, etc., respectively. In some embodiments, the propulsion controls may transmit signals to a vehicle computer (e.g., drive-by-wire), which in turn may control corresponding propulsion components of the propulsion system. Therefore, in some embodiments, the vehicle 10 may be an autonomous vehicle.

[0030] In some embodiments, the vehicle 10 includes a transmission that is connected to the crankshaft via a flywheel or a clutch or a fluid coupling. In some embodiments, the transmission includes a manual transmission. In some embodiments, the transmission includes an automatic transmission. In the case of an internal combustion engine or a hybrid vehicle, the vehicle 10 may include one or more pistons that operate in conjunction with the crankshaft to generate a force that is transmitted through the transmission to rotate one or more axles of the wheels 22. When the vehicle 10 includes one or more electric motors, the vehicle battery and / or fuel cell provides energy to the electric motors to rotate the wheels 22.

[0031] The vehicle 10 may include an automatic vehicle propulsion system, such as cruise control, adaptive cruise control, automatic braking control, other automatic vehicle propulsion systems, or combinations thereof. The vehicle 10 may be an autonomous or semi-autonomous vehicle, or other suitable type of vehicle. The vehicle 10 may include more or fewer features than those generally illustrated and / or disclosed herein.

[0032] In some embodiments, the vehicle 10 may include an Ethernet component 24, a controller area network (CAN) bus 26, a media oriented system transport component (MOST) 28, a FlexRay component 30 (e.g., a wire control brake system, etc.), and a local interconnect network component (LIN) 32. The vehicle 10 may use the CAN bus 26, the MOST 28, the FlexRay component 30, the LIN 32, other suitable networks or communication systems, or a combination thereof to transmit various information from sensors, such as those inside or outside the vehicle, to various processors or controllers, such as those inside or outside the vehicle. The vehicle 10 may include more or fewer features than those generally illustrated and / or disclosed herein.

[0033] In some embodiments, although not shown, the vehicle 10 may include a steering system, such as an EPS system, a steer-by-wire steering system (e.g., which may include or communicate with one or more controllers that control components of the steering system without using a mechanical connection between a steering wheel of the vehicle 10 and the wheel 22), a hydraulic steering system (e.g., which may include a magnetic actuator incorporated into a valve assembly of the hydraulic steering system), or other suitable steering systems.

[0034] The steering system may include an open-loop feedback control system or mechanism, a closed-loop feedback control system or mechanism, or a combination thereof. The steering system may be configured to receive various inputs, including, but not limited to, steering wheel position, input torque, one or more road wheel positions (road wheels), vehicle speed, temperature, other suitable inputs or information (such as any signal available on a vehicle communication bus), or a combination thereof.

[0035] Additionally or alternatively, the input may include steering wheel torque, steering wheel angle, motor speed, vehicle speed, estimated motor torque command, other suitable inputs, or combinations thereof. The steering system may be configured to provide steering functionality and / or control to the vehicle 10. For example, the steering system may generate an assist torque based on various inputs. The steering system may be configured to use the assist torque to selectively control the motor of the steering system to provide steering assistance to the operator of the vehicle 10. The steering system of the present disclosure is configured to implement a SOH monitoring system and method, as described in more detail below.

[0036] In some embodiments, vehicle 10 may include a controller, such as Figure 1B 100 is generally shown in FIG. 100. The controller 100 may include any suitable controller, such as an electronic control unit or other suitable controller. The controller 100 may be configured to control various functions of, for example, a steering system and / or various functions of the vehicle 10. The controller 100 may include a processor 102 and a memory 104. The processor 102 may include any suitable processor, such as the processor described herein. Additionally or alternatively, the controller 100 may include any suitable number of processors as a supplement or replacement to the processor 102. The memory 104 may include a single disk or multiple disks (e.g., a hard disk drive), and include a storage management module that manages one or more partitions within the memory 104. In some embodiments, the memory 104 may include a flash memory, a semiconductor (solid-state) memory, etc. The memory 104 may include a random access memory (RAM), a read-only memory (ROM), or a combination thereof. The memory 104 may include instructions that, when executed by the processor 102, cause the processor 102 to control at least various aspects of the vehicle 10. Additionally or alternatively, the memory 104 may include instructions that, when executed by the processor 102, cause the processor 102 to perform functions associated with the systems and methods described herein.

[0037] The controller 100 may receive one or more signals indicating sensed or measured characteristics of the vehicle 10 from various measurement devices or sensors 106. The sensors 106 may include any suitable sensors, measurement devices, and / or other suitable mechanisms. For example, the sensors 106 may include one or more torque sensors or devices, one or more steering wheel position sensors or devices, one or more motor position sensors or devices, one or more position sensors or devices, other suitable sensors or devices, or combinations thereof. The one or more signals may indicate steering wheel torque, steering wheel angle, motor speed, vehicle speed, other suitable information, or combinations thereof.

[0038] As used herein, a "controller" may refer to a hardware module or component including one or more processors or microcontrollers, memory, sensors, one or more actuators, communication interfaces, etc., any portion of which may be collectively referred to as a "circuit". As described herein, the corresponding functions and steps performed by a given controller, control circuit, etc. may be performed by multiple controllers, processors, etc. in common. For example, a processor, processing device, controller, control circuit, etc. "configured to perform" may refer to a single processor, processing device, controller, etc. configured to perform both A and B, or may refer to a first processor, processing device, controller, etc. configured to perform A and a second processor, processing device, controller, etc. configured to perform B. For simplicity, a "control circuit configured to perform A and B" may refer to a single or multiple processors, processing devices, controllers, etc. that are collectively configured to perform A and B. In some examples, one or more functions may be performed remotely (e.g., relative to a vehicle), such as at a controller, processor, circuit, etc. of a remote server, cloud computing system, and / or other remote processing system.

[0039] In some embodiments, the controller 100 may perform the methods described herein. However, the fact that the methods described herein are performed by the controller 100 is not meant to be limiting, and any type of software executed on a controller or processor may perform the methods described herein without departing from the scope of the present disclosure. For example, a controller (such as a processor executing software within a computing device) may perform the methods described herein.

[0040] Figure 2 An example EPS system 200 in accordance with the principles of the present disclosure is generally schematically illustrated. Although described with respect to an EPS system, the principles of the present disclosure may be implemented with other types of steering systems (such as SbW and ADAS systems) as well as non-steering systems.

[0041] EPS system 200 includes a steering system 204. For simplicity, details of steering system 204 are omitted. For example, steering system 204 can include a rack-and-pinion type steering mechanism that responds to operator input (e.g., a steering wheel, a hand wheel, etc.). In some examples, steering assistance can be provided via an electric machine such as motor 208 (e.g., a permanent magnet synchronous motor).

[0042] The motor 208 is responsive to a controller or control circuit 212, which receives power from a power source 216 (which may include a battery, an alternator, etc.) via a wiring harness 220 to control the motor 208. Although shown as a single connection between the power source 216 and the controller 212 for simplicity, the wiring harness 220 may include multiple wired connections to various components of the EPS system 200, such as one or more direct connections to the motor 208. The wiring harness 220 may include one or more conductors, such as wire segments, busbars, etc. In some examples, the wiring harness 220 includes one or more connectors, such as spade connectors, sockets, plugs, lugs, terminals, etc. In addition, although described with respect to a single controller 212, the EPS system 200 may include multiple controllers, each having different connections between the controller and the power source 216, a corresponding motor, etc., and the SOH, AH, and RUL of the electrical connections of the corresponding controllers, motors, etc. may be calculated according to the principles of the present disclosure.

[0043] The controller 212 receives various measurement signals from corresponding sensors, including but not limited to one or more sensors 224 configured to generate measurement signals associated with the steering system 204, and vehicle state information (vehicle speed, mileage, temperature, etc.) received through the vehicle communication bus. The measurement signals may include a steering angle (e.g., measured by a position sensor) and a motor speed. The motor speed, represented as ω_m, may be measured, calculated, or a combination thereof. For example, the motor speed ω_m may be calculated as a change in the motor position as measured by the position sensor within a specified time interval. For example, the motor speed ω_m may be determined as a derivative of the motor position θ by the following equation: ω_m=Δθ / Δt, where Δt is the sampling time and Δθ is the change in position during the sampling interval. Alternatively, the motor speed may be derived from the motor position as a time rate of change of the position.

[0044] The controller 212 controls the motor 208 based on various inputs, measurement signals, etc. to provide torque assistance to the steering system 204. For example, the controller 212 is configured to supply a corresponding voltage to the motor 208 via an inverter (not shown) so that the motor 208 generates a desired torque and / or position, and the inverter may optionally be incorporated into the controller 212.

[0045] The wiring harness 220 has an associated resistance (e.g., harness resistance) that represents the resistance of electrical components in the current flow path between the power source 216 and the input of the controller 212 (including the path to and from the controller 212). For example, the harness resistance has a harness resistance value R 线束, which is the sum of the resistances of the wiring harness 220, the vehicle ground, and one or more connectors or connections. Over time, these connections may corrode and / or degrade and cause the total path resistance between the power source 216 and the controller 212 to increase. Therefore, the degradation of the connection can be determined based on the harness resistance.

[0046] Figure 3 An example degradation of a performance factor P (e.g., for a limiting performance factor P(L)) over the life of an electrical connection t(L) is illustrated. After the formation period shown at 300, the performance is relatively stable (i.e., relatively flat) for period 304 before experiencing accelerated aging and performance degradation in period 308. Thus, while resistance may generally indicate degradation, resistance alone may not accurately indicate AH and RUL. Although shown as generally increasing over period 300, the performance factor P may vary (e.g., increase, decrease, etc.) over period 300. For example, period 300 may correspond to a "settling" period where various components, materials, connections, etc. stabilize after installation.

[0047] Figure 4 Examples of AH calculated using a usage-based technique, AH calculated using a behavior-based technique, RUL calculated using a usage-based technique, RUL calculated using a behavior-based technique, and measured resistance (exponential resistance) are illustrated. For reference, an exemplary critical resistance is shown at 400. As used herein, critical resistance 400 is selected as a resistance value indicating that significant degradation of the electrical connection has occurred (e.g., degradation sufficient to produce performance degradation that can be noticed by the driver). In addition, when critical resistance 400 is reached, the measured resistance may begin to increase exponentially as shown at 404, thereby indicating accelerated aging.

[0048] In different examples, the critical resistance can be set based on different metrics, including but not limited to: based on when the resistance begins to increase exponentially; based on when the resistance reaches a calibrable predetermined resistance (e.g., 20 milliohms) that is known to cause significant performance degradation; based on when the resistance is a multiple (e.g., 1.5 times, 2 times, etc.) of the lowest known resistance value (i.e., historical), at which point significant degradation has occurred from a stable baseline condition; and based on when the resistance is within a predetermined or variable range of a critical value requiring maintenance.

[0049] Thus, the SOH technique can calculate AH and RUL to attempt to predict when the measured resistance will reach or exceed a selected critical resistance. As described herein, the measured resistance can be obtained using various techniques, such as by applying a sinusoidal current, measuring the response (e.g., a voltage response) at one or more inputs, and calculating the resistance based on the current and the measured response, as described in U.S. Patent Application No. 17 / 733,434, which is incorporated herein by reference.

[0050] As shown at 408 and 412, respectively, the behavior-based technique inaccurately indicates AH and RUL during a first early-life period (e.g., before 30 months). However, as shown at 416 and 420, respectively, the behavior-based technique begins to more accurately indicate AH and RUL in a second late-life period (e.g., after 30 months). In other words, because the resistance and other behavior-based measurements, calculations, or estimates may be relatively "flat" or constant during the early-life period, the behavior-based technique inaccurately indicates AH and RUL in the early-life period.

[0051] In contrast, as shown at 424 and 428, respectively, the usage-based technique results in a substantially linear calculation of AH and RUL. In other words, because the usage-based technique may be based at least in part on the time of use, the AH and RUL calculated according to the usage-based technique will generally decrease as use increases. However, because degradation is not linear and tends to accelerate near the end of life, the substantially linear results of the usage-based technique are less accurate near the end of life. For example, as shown at 432, the AH and RUL values ​​indicated by the usage-based results exceed the corresponding AH and RUL values ​​for the behavior-based results, and exceed the AH and RUL values ​​at the point where the measured resistance reaches or exceeds the selected critical resistance.

[0052] FIG. 5A to FIG. 5E Various example AH calculation methods configured to implement a combination of usage-based and behavior-based techniques in accordance with the principles of the present disclosure are illustrated. Although described with respect to AH calculation, FIG. 5A to FIG. 5E The principles described in can also be implemented for RUL calculations. As described herein, the combination of usage-based techniques and behavior-based techniques in accordance with the principles of the present invention may be referred to as blended techniques, hybrid techniques, combined techniques, and the like.

[0053] In the examples described below, both usage-based and behavior-based techniques are calculated and merged / combined. However, simply combining usage-based and behavior-based techniques may result in ambiguous or inconsistent results (e.g., AH values ​​and / or RUL values ​​become fixed over long periods of time, increase or decrease dramatically, etc.). Various examples of using a combination of usage-based and behavior-based techniques to obtain consistent and accurate AH values ​​and / or RUL values ​​over the life of an electrical connection are provided in the examples below.

[0054] Figure 5A A first example of a combination of a usage-based technique and a behavior-based technique (e.g., a first "hybrid-based" technique) is illustrated. In this example, the usage-based technique is used for a first time period. Thus, for the first time period, the results of the first hybrid-based technique, as shown at 500, correspond to the substantially linear usage-based results, as shown at 424. Conversely, the behavior-based technique is used for a second time period. Thus, for the second time period, the results of the first hybrid-based technique, as shown at 502, correspond to the behavior-based results, as shown at 416. In this way, the results of the first hybrid-based technique provide the accuracy of the usage-based technique in an early life period of the electrical connection and the accuracy of the behavior-based technique in a late life period of the electrical connection.

[0055] Various techniques may be used to transition between the usage-based technique and the behavior-based technique. For example, if the results of the first hybrid-based technique simply transitioned directly to the behavior-based technique at the end of the selected first time period, the results of the first hybrid-based technique would simply spike upward as shown at 504. To avoid such a result, the results of the first hybrid-based technique may be maintained at a value corresponding to the transition from the first time period to the second time period, as shown at 506. For example, the results of the first hybrid-based technique may be maintained at value 506 until the results of the behavior-based technique "catch up" with the usage-based technique (i.e., decrease to the same value as the usage-based technique). In this example, the results of the first hybrid-based technique are maintained at 50% until the results of the behavior-based technique also reach 50%, and then begin to follow the results of the behavior-based technique for the remainder of the life of the electrical connection, which may cause the AH value and / or RUL value to become fixed or unchanged over a long period of time.

[0056] The transition between the first time period and the second time period (i.e., between using the usage-based technique and using the behavior-based technique) can be time-based, measurement-based, or a combination thereof. For example, as shown, the transition can be performed based on the AH value obtained for the usage-based technique. In this example, the result of the first hybrid-based technique is maintained / remained at a threshold AH (here, 50%) until the result of the behavior-based technique also reaches 50%. In other examples, other thresholds can be used.

[0057] Figure 5B A second example of a combination of a usage-based technique and a behavior-based technique is illustrated (e.g., a second "hybrid-based" technique, which may be referred to as a "hybrid-weighted" technique). The result of the second hybrid-based technique is shown at 508. In this example, a blending or combination technique is used to calculate a combination of the results of the usage-based technique and the behavior-based technique. For example, the result of the second hybrid-based technique may correspond to an average or weighted average of the usage-based technique and the behavior-based technique.

[0058] In one example, the second hybrid-based technology may be configured so that the results of the second hybrid-based technology are increasingly weighted toward the results of the behavior-based technology as usage and / or time increases. For example, during a period corresponding to the substantially "flat" results of the behavior-based technology shown at 408, the results of the use-based technology may be weighted with a weight greater than 50% in the calculation of the results of the second hybrid-based technology. Conversely, during a period corresponding to the reduced results of the behavior-based technology shown at 416, the results in the results of the use-based technology may be weighted with a weight less than 50%, while the results of the behavior-based technology may be weighted with a weight greater than 50%. In one example, for the weighted average calculation, an initial maximum weight (e.g., 100%, 90%, etc.) is assigned to the results of the use-based technology, which decreases (linearly or nonlinearly, stepwise, etc.) as the number of months of use increases, as the AH decreases, etc. Conversely, an initial minimum weight (e.g., 0%, 10%, etc.) is assigned to the results of the use-based technology, which decreases (linearly or nonlinearly, stepwise, etc.) as the number of months of use increases.

[0059] Figure 5C A third example of a combination of a usage-based technique and a behavior-based technique (e.g., a third "hybrid-based" technique, which may be referred to as a "hybrid-weighted" technique) is illustrated. The results of the third hybrid-based technique are shown at 512. In this example, the same method as described above with respect to Figure 5BThe hybrid weighted technique described herein is similar to a blending or combining technique to calculate a combination of the results of the usage-based technique and the behavior-based technique. For example, the result of the third hybrid-based technique may correspond to an average or weighted average of the usage-based technique and the behavior-based technique. However, in this example, the result of the third hybrid-based technique is configured to completely transition to the result of the behavior-based technique in response to determining that the result of the behavior-based technique is less than the result of the usage-based technique, as shown at 514. In other words, the result of the third hybrid-based technique corresponds to an average or weighted average of the usage-based technique and the behavior-based technique until the result of the behavior-based technique is less than the result of the usage-based technique. In some examples, the transition to the result of using the behavior-based technique may be based on other values ​​and comparisons, such as transitioning in response to determining that the result of the behavior-based technique is within a threshold of the result of the usage-based technique (e.g., within 10% of the result).

[0060] For example, Figure 5C As shown, the results of the behavior-based technique begin to decrease earlier (i.e., months earlier) than in the previous example (e.g., because the measured resistance 404 and / or other indicators of degradation increase faster than in the previous example). Therefore, continuing to use the average or weighted average of the usage-based technique and the behavior-based technique after the point indicated at 514 will cause the results of the third hybrid-based technique to inaccurately indicate a larger AH (or RUL). The third hybrid-based technique corrects for this inaccuracy.

[0061] Figure 5D Another example of the results of the third hybrid-based technology is illustrated. The results of the third hybrid-based technology in this example are shown at 520. In this example, the results of the behavior-based technology begin to decrease much later (i.e., months later) than in the previous example (e.g., because the measured resistance 404 and / or other indicators of degradation increase more slowly than in the previous example). Therefore, using the average or weighted average of the use-based technology and the behavior-based technology during the entire period of the relatively long "flat" area of ​​the results of the behavior-based technology as shown at 408 causes the results to curve upward (a "curve rise" event) as shown at 522. The upward curve 522 is caused by the following: as time passes and the flat area 408 becomes longer, the results of the use-based technology decrease relatively quickly, while increasing the weight applied to the results of the behavior-based technology. For example, as the results of the use-based technology decrease, the weighted average moves away from the results of the use-based technology and toward the results of the behavior-based technology, resulting in an upward curve 522.

[0062] Figure 5EA fourth example of a combination of a usage-based technique and a behavior-based technique (e.g., a fourth "hybrid-based" technique, which may be referred to as a "hybrid-weighted" technique) is illustrated that is configured to minimize or eliminate the upward curve 522. The results of the fourth hybrid-based technique are shown at 530. The fourth hybrid-based technique modifies the third hybrid-based technique by extending the results of the usage-based model to exceed the typical estimated lifespan of the electrical connection. For example, in the previous example, the usage-based model may be configured to generate results based in part on the typical estimated lifespan of the electrical connection (such as 70 to 80 months or longer). The typical estimated lifespan may be significantly longer than 80 months, and these values ​​are selected for illustration purposes only. The configuration is shown at 530. FIG. 5A to FIG. 5D The results based on the techniques used are indicated in each of the Figures at 424.

[0063] On the contrary, Figure 5E As shown, the usage-based technique is configured to generate results based on an estimated life that is much longer than the typical estimated life (e.g., a modified estimated life). In some examples, the modified estimated life is 1.5 times, 2 times, 2.5 times, etc., the typical estimated life. As shown, using the modified estimated life causes the results of the usage-based technique to extend beyond 120 months. Thus, the fourth hybrid-based technique compensates for the potential for Figure 5D The conditions of the upward curve 522 are shown.

[0064] For example, since the shift in the weighted average is determined based on the results of the usage-based techniques, maintaining the results of the usage-based techniques at a higher value for a longer period of time prevents the upward curve 522. In an example, the transition to assigning a higher weight to the results of the behavior-based techniques than to the results of the usage-based techniques may occur in response to the AH of the results of the usage-based techniques decreasing below 50%. Since this decrease to below 50% is relative to Figure 5D The example shown occurs later, so the results of the fourth hybrid-based technique continue to be weighted more heavily toward the results of the usage-based technique (eg, until the point indicated at 532 ).

[0065] Figure 6 600 is a flowchart generally illustrating the steps of an example method 600 for calculating AH and / or RUL according to the principles of the present disclosure. The method may be performed by one or more components of the system described herein, such as one or more controllers (e.g., controller 100), one or more processors or processing devices (e.g., processor 102), and / or other circuits. In an example, one or more processors are configured to execute instructions stored in a memory to perform method 600.

[0066] At 604, the values ​​of one or more indicators of the SOH of the electrical connection, such as the AH value and / or the RUL value, are initialized. For example, the AH value and the RUL value are initialized to corresponding values ​​when the electrical connection is installed or formed. As an example, the initialization value of AH is a maximum value (e.g., 100%), and the initialization value of RUL is a predetermined baseline RUL value, such as 60 months, 70 months, etc. In some examples (e.g., as described above with respect to Figure 5E The initialization value of RUL is significantly greater than the typical expected life of the electrical connection, such as 1.5 times the typical expected life, 2 times the typical expected life, 2.5 times the typical expected life, etc. At 608, the vehicle is operated after the electrical connection is installed and the AH value and the RUL value are initialized. For example, a user or driver operates the vehicle.

[0067] At 612, one or more measurements indicative of AH and / or RUL are generated and received. The measurements may include, but are not limited to, one or more resistances associated with an electrical connection as described herein. In an example, electrical power is applied as a sinusoidal current to a motor associated with an EPS system, a response corresponding to the applied power is measured, and the resistance of the electrical connection is calculated based on the current and the response. Other measurements may include measurements associated with use of the vehicle (i.e., usage-based measurements, such as length of time since the electrical connection was installed, actual use / driving time of the vehicle, etc.) and / or measurements associated with driver / vehicle behavior (i.e., behavior-based measurements, such as current applied to the motor, current from a power source, operating characteristics associated with vibration, environmental factors and conditions, etc.).

[0068] At 616, AH, RUL, or both AH and RUL are calculated using usage-based techniques and behavior-based techniques. In other words, AH is calculated using usage-based techniques and AH is calculated separately using behavior-based techniques, and / or RUL is calculated using usage-based techniques and RUL is calculated separately using behavior-based techniques. Thus, in some examples, two separate values ​​are calculated for AH, and / or two separate values ​​are calculated for RUL. AH values ​​and RUL values ​​are calculated using corresponding AH models or algorithms and RUL models or algorithms that are configured to receive one or more inputs indicating AH / RUL (e.g., a calculated resistance associated with a connection and / or other measurements described herein) and calculate AH / RUL based on the received inputs. In some examples, the AH model and the RUL model are machine learning models.

[0069] At 620, AH, RUL, or both AH and RUL are calculated using a hybrid-based technique (e.g., a hybrid weighted-based technique) as described herein. For example, AH and RUL are each calculated using a hybrid-based technique by combining the corresponding usage-based and behavior-based values ​​calculated at 616. In one example, AH and RUL are calculated using a weighted average of the usage-based and behavior-based values ​​(e.g., by a model, algorithm, etc.). Various weights and other parameters used for the calculations may be stored in a memory (such as memory 104) and retrieved by method 600 (e.g., by processor 102) to perform the calculations.

[0070] In some examples, the weights may be retrieved from a lookup table that relates a plurality of different weights (to be applied to each of the usage-based value and the behavior-based value) to different variable conditions (such as the time elapsed since the electrical connection was installed, the calculated behavior-based value and / or the usage-based value, etc.) In other examples, the weights may be calculated to simply decrease (e.g., for the usage-based value) and / or increase (e.g., for the behavior-based value) over time as the usage-based value and / or the behavior-based value decreases, etc.

[0071] At 624, one or more actions are performed based on the results of the hybrid-based technique (i.e., the calculated AH and / or RUL). For example, the calculated values ​​of AH and / or RUL may be provided to a driver or user, a manufacturer, a dealer, a service organization, etc. As an example, the calculated values ​​are provided to the driver or user via an in-vehicle display or interface (e.g., a display of an infotainment system or other dashboard indicator), a mobile device, etc. In this way, the user of the vehicle is provided with an accurate indicator of the SOH, RUL, etc. of one or more components of the vehicle. The data may be sent to a remote server or cloud computing system for remote analysis, to a local diagnostic tool attached to the vehicle (e.g., an OBDII reader or other diagnostic device), and the like.

[0072] In another example, the vehicle (and / or another entity receiving the calculation results) is configured to perform one or more remedial actions based on the calculated values. For example, the systems and methods of the present disclosure (e.g., using controller 100) may be configured to compare the calculated AH value and / or RUL value with corresponding thresholds to determine whether to perform the one or more remedial actions. In other words, the one or more remedial actions may be performed in response to the AH value and / or RUL value decreasing below the corresponding threshold. In one example, in response to the AH value and / or RUL value decreasing below the corresponding threshold, a notification or warning may be generated and provided to the driver or user, manufacturer, dealer, service agency, etc. The notification (e.g., a check engine light or other indicator) may indicate that the vehicle needs maintenance, recommend that the driver or user arrange maintenance to replace the electrical connection, and so on.

[0073] In another example, in response to the AH value and / or the RUL value decreasing below a corresponding threshold, control of one or more vehicle operating parameters (e.g., current provided to a motor, controller, etc.) may be adjusted under various conditions (e.g., when a measured temperature of the vehicle or a vehicle system is above a threshold). For example, as the AH value and / or the RUL value decreases, various parameters (e.g., current provided to a motor) may be controlled to minimize additional wear on the electrical connections and avoid failures.

[0074] The above discussion is intended to illustrate the principles and various embodiments of the present invention. Once the above disclosure is fully understood, many changes and modifications will become apparent to those skilled in the art. The appended claims are intended to be interpreted as covering all such changes and modifications.

[0075] The word "example" is used herein to mean used as an example, instance or illustration. Any aspect or design described as an "example" herein is not necessarily to be interpreted as being preferred or advantageous over other aspects or designs. On the contrary, the use of the word "example" is intended to present the concept in a concrete way. As used in this application, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X includes A or B" is intended to represent any one of the natural inclusive arrangements. That is, if X includes A; X includes B; or X includes both A and B, "X includes A or B" is satisfied under any of the aforementioned examples. In addition, the article "one" as used in this application and the appended claims should generally be interpreted as meaning "one or more", unless otherwise specified or clear from the context to refer to the singular form. In addition, the use of the term "a specific implementation" or "a specific implementation" throughout the text is not intended to represent the same embodiment or specific implementation, unless so described.

[0076] The specific implementation of the systems, algorithms, methods, instructions, etc. described herein can be implemented in hardware, software, or any combination thereof. The hardware may include, for example, a computer, an intellectual property (IP) core, an application specific integrated circuit (ASIC), a programmable logic array, an optical processor, a programmable logic controller, microcode, a microcontroller, a server, a microprocessor, a digital signal processor, or any other suitable circuit. In the claims, the term "processor" should be understood to include any of the foregoing hardware, either alone or in combination. The terms "signal" and "data" are used interchangeably.

[0077] As used herein, the term module may include: a packaged functional hardware unit designed for use with other components, an instruction set that can be executed by a controller (e.g., a processor that executes software or firmware), a processing circuit configured to perform a specific function, and an independent hardware or software component that interfaces with a larger system. For example, a module may include an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a circuit, a digital logic circuit, an analog circuit, a combination of discrete circuits, gates, and other types of hardware, or a combination thereof. In other embodiments, a module may include a memory that stores instructions that can be executed by a controller to implement the features of the module.

[0078] Furthermore, in one aspect, for example, a general purpose computer or general purpose processor with a computer program can be used to implement the system described herein, which when executed implements any of the corresponding methods, algorithms and / or instructions described herein. Additionally or alternatively, for example, a special purpose computer / processor can be utilized, which may include other hardware for implementing any of the methods, algorithms or instructions described herein.

[0079] In addition, all or part of the specific implementation of the present disclosure may take the form of a computer program product accessible from, for example, a computer usable medium or a computer readable medium. A computer usable medium or a computer readable medium may be any device capable of, for example, tangibly containing, storing, transmitting or transporting a program for use by or in conjunction with any processor. The medium may be, for example, an electronic, magnetic, optical, electromagnetic or semiconductor device. Other suitable media are also available.

[0080] The above embodiments, specific implementations and aspects have been described to allow easy understanding of the present invention and do not limit the present invention. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, and its scope should be given the broadest interpretation to cover all such modifications and equivalent structures permitted under the law.

Claims

1. A method for determining a health state of an electrical connection in a steering system of a vehicle, the method comprising using a processor configured to execute instructions: receiving an input indicative of the state of health of the electrical connection, wherein the input comprises a resistance associated with the electrical connection, and wherein the state of health corresponds to at least one of a cumulative health of the electrical connection and a remaining useful life of the electrical connection; calculating a first health status value based on the received input and usage associated with the vehicle; calculating a second health status value based on the received input and the behavior associated with the vehicle; calculating a third state-of-health value based on the first state-of-health value and the second state-of-health value, wherein the third state-of-health value is an indicator of the cumulative health or the remaining useful life of the electrical connection; and At least one action is performed based on the third health status value. 2 . The method of claim 1 , wherein the method further comprises obtaining the resistance by supplying a sinusoidal current to a motor of the steering system, measuring a response of the motor, and calculating the resistance based on the sinusoidal current and the measured response. The method according to claim 2 , wherein the sinusoidal current is a current that does not generate torque. 4 . The method of claim 1 , wherein the steering system is an electronic power steering system, and the electrical connection is an electrical connection between a power source and a motor of the electronic power steering system. 5 . The method of claim 1 , wherein the method further comprises calculating the third health status value as a weighted average of the first health status value and the second health status value.

6. The method of claim 5, wherein the method further comprises assigning weights to the first state of health value and the second state of health value based on at least one of (i) a time elapsed since the electrical connection was installed and (ii) the first state of health value.

7. The method according to claim 5, wherein the method further comprises: decreasing a first weight assigned to the first state-of-health value as at least one of (i) a time elapsed since the electrical connection was installed increases and (ii) the first state-of-health value decreases; as well as A second weight assigned to the second health status value increases as the first weight decreases.

8. The method of claim 1, wherein the method further comprises initializing the first state-of-health value and the second state-of-health value, wherein initializing the first state-of-health value comprises setting the first state-of-health value to a value greater than an expected remaining useful life of the electrical connection.

9. The method according to claim 1, wherein the method further comprises: comparing the first health status value with a threshold; In response to determining that the first health status value is greater than or equal to the threshold, setting the third health status value to the first health status value; as well as In response to determining that the first state-of-health value is less than the threshold, the third state-of-health value is set to the second state-of-health value.

10. The method of claim 1, wherein the first health status value is a first cumulative health value, the second health status value is a second cumulative health value, and the third health status value is a third cumulative health value, the method further comprising: calculating a first remaining useful life value based on the received input and usage associated with the vehicle; calculating a second remaining useful life value based on the received input and the behavior associated with the vehicle; as well as A third remaining useful life value is calculated based on the first remaining useful life value and the second remaining useful life value.

11. The method of claim 1 , wherein performing the at least one action comprises at least one of: generating and displaying an indicator of the third health status value; and At least one operating parameter of the vehicle is controlled based on the third state-of-health value.

12. A system for determining the health of an electrical connection in a steering system of a vehicle, the system comprising: at least one sensor configured to generate an output indicative of the state of health of the electrical connection, wherein the output is indicative of a resistance associated with the electrical connection, and wherein the state of health corresponds to at least one of a cumulative health of the electrical connection and a remaining useful life of the electrical connection; controller, the controller being configured to receiving as input said output generated by said at least one sensor; calculating a first health status value based on the received input and usage associated with the vehicle, calculating a second health status value based on the received input and the behavior associated with the vehicle, calculating a third state-of-health value based on the first state-of-health value and the second state-of-health value, wherein the third state-of-health value is an indicator of the cumulative health or the remaining useful life of the electrical connection, and At least one action is performed based on the third health status value.

13. The system of claim 12, wherein the controller is configured to obtain the resistance by supplying a sinusoidal current to a motor of the steering system, measuring a response of the motor sensed by the at least one sensor, and calculating the resistance based on the sinusoidal current and the measured response.

14. The system of claim 13, wherein the sinusoidal current is a current that does not produce torque.

15. The system of claim 12, wherein the steering system is an electronic power steering system and the electrical connection is an electrical connection between a power source and a motor of the electronic power steering system. 16 . The system of claim 12 , wherein the controller is configured to calculate the third health state value as a weighted average of the first health state value and the second health state value.

17. The system of claim 16, wherein the controller is configured to assign weights to the first state-of-health value and the second state-of-health value based on at least one of (i) a time elapsed since the electrical connection was installed and (ii) the first state-of-health value.

18. The system of claim 16, wherein the controller is configured to: decreasing a first weight assigned to the first state-of-health value as at least one of (i) a time elapsed since the electrical connection was installed increases and (ii) the first state-of-health value decreases; and A second weight assigned to the second health status value increases as the first weight decreases.

19. The system of claim 12, wherein the controller is configured to initialize the first state-of-health value and the second state-of-health value, wherein initializing the first state-of-health value comprises setting the first state-of-health value to a value greater than an expected remaining useful life of the electrical connection.

20. The system of claim 12, wherein the first health status value is a first cumulative health value, the second health status value is a second cumulative health value, and the third health status value is a third cumulative health value, and wherein the controller is configured to: calculating a first remaining useful life value based on the received input and usage associated with the vehicle; calculating a second remaining useful life value based on the received input and the behavior associated with the vehicle; and A third remaining useful life value is calculated based on the first remaining useful life value and the second remaining useful life value.

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