Early life fault detection for power pack resistance

Abstract

A method for detecting an early life failure of an electrical connection of a power harness of a steering system of a vehicle, the method comprising using a processor configured to execute instructions: obtaining a resistance measurement associated with an electrical power delivery system comprising the electrical connection; obtaining historical resistance data; obtaining at least one limit based on at least one of the historical resistance data and the functional limit; detecting an early life failure of the electrical connection based on a comparison between the resistance measurement and the at least one limit; in response to detecting the early life fault, at least one action is performed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 542,442, 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 electric 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 electric 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. 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] In an example, a method for detecting an early life failure of an electrical connection of an electrical wiring harness of a steering system of a vehicle includes using a processor configured to execute instructions: obtaining a resistance measurement associated with an electrical power delivery system including the electrical connection; obtaining historical resistance data; obtaining at least one limit based on the historical resistance data and at least one of a functional limit; detecting an early life failure of the electrical connection based on a comparison between the resistance measurement and the at least one limit; and performing at least one action in response to detecting the early life failure.

[0007] A method for detecting an early life failure of an electrical connection of a power harness of a steering system of a vehicle, comprising using a processor configured to execute instructions: after the power harness is installed in the vehicle, obtaining a first resistance measurement result associated with the electrical connection; after the first resistance measurement result, obtaining a second resistance measurement result associated with the electrical connection; detecting an early life failure of the electrical connection based on at least one of a comparison between the first resistance measurement result and a first resistance threshold and a comparison between the second resistance measurement result and the second resistance threshold; and, in response to detecting the early life failure, performing at least one action.

[0008] Other aspects of the disclosed embodiments include systems configured to perform the steps and functions of the described methods.

[0009] 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

[0010] 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.

[0011] Figure 1A A vehicle in accordance with the principles of the present disclosure is generally shown.

[0012] Figure 1B A controller according to the principles of the present disclosure is generally shown.

[0013] Figure 2 An example electric power steering (EPS) system according to the principles of the present disclosure is generally shown schematically.

[0014] Figure 3 Example degradation of an electrical connection during its useful life is generally shown.

[0015] Figure 4A and Figure 4B The resistance measurements are generally shown relative to upper and lower control limits.

[0016] Figure 4C is a flow chart generally illustrating the steps of an example method for detecting early life failures according to the principles of the present disclosure.

[0017] Figure 5 is a flow chart generally illustrating the steps of another example method for detecting early life failures according to the principles of the present disclosure. DETAILED DESCRIPTION

[0018] 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 as an example of that embodiment, and is not intended to imply that the scope of the present disclosure (including the claims) is limited to that embodiment.

[0019] 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 electric 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.

[0020] Vehicles typically include one or more motors, such as electric motors configured to control various aspects of the steering system of the vehicle. A path for providing power from a vehicle power source (e.g., battery, alternator, power supply) to a motor controller or one or more motors of the steering system can be provided. The path may include one or more wiring harnesses, wires, connectors, terminals, fuses, or other (e.g., non-traditional) paths for conducting current, such as chassis grounding, busbars, through engine blocks, etc. Anything that can provide a sufficiently low impedance path (high power connection) for energy transfer can be used to provide power to or from the motor controller. High power electrical harnesses and connectors can supply electrical power from the vehicle electrical system (e.g., battery and / or 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 degrade, resulting in the eventual inability to provide enough 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 supply current draw through the increased resistance of the high power connection or wiring harness will result in a large voltage drop between the vehicle power supply and the motor controller, which can cause the total voltage at the motor controller input to be low enough to cause a "shutdown" or "drop from operating state", which can result in loss of functionality, such as loss of assist in an EPS system and / or 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 can result in lower torque assist, laggy response, poor feedback, reduced angle control, and overall reduced steering performance.

[0021] In some embodiments, it is desirable to detect the degradation condition and / or limit the electromechanical output power command based on the detection of 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 is preferable to alternatives, which may include complete loss of assistance or angle control functionality.

[0022] Some systems may implement techniques for determining degradation of an 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 quantities of the applied motor voltage and the vector quantities 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 drop or change in voltage, such as a drop or change in voltage at the bridge voltage of an inverter or the input of a control module) indicates degradation and a state of health (SOH) of the input power connection.

[0023] In some examples, detectable degradation generally increases over time (e.g., exponentially, linearly, etc.) in some predictable manner. For example, a measurement of a representative resistance (e.g., a resistance associated with a power connector or wiring harness as described above) may generally increase over time as degradation increases. However, in other examples, one or more faults, material or installation inconsistencies, etc. may interfere with the electrical connection, resulting in an increase in the initial resistance associated with the electrical connection, which may lead to early life failures of the electrical connection. As used herein, "early life failure" refers to the failure of an electrical connection significantly (e.g., 50% or more) earlier than the expected or typical life of the electrical connection. These early life failures may be caused by manufacturing defects, contamination, process / installation defects, etc., including but not limited to: loose or untightened bolts or other connections; partially inserted contacts / terminals; corrosion or contamination on and / or between electrical connections; crimping / stripping failures; and damaged wires or wire strands.

[0024] The early life fault detection systems and methods according to the present disclosure are configured to detect early life faults (e.g., before operating the vehicle, before selling the vehicle to a user, etc., early in the life of the vehicle, such as within the first 300 hours, within the first 100 cycles, etc.), as described in more detail below.

[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 shown. 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 shown 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 open position, the hood 14 provides access to the engine compartment 20, and when the hood 14 is in a second position, or 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 generally shown.

[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 (e.g., for a hybrid vehicle) propulsion system including a combination of an internal combustion engine and one or more electric motors, 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, a propulsion controller (such as an accelerator actuator (e.g., an accelerator pedal), a brake actuator (e.g., a brake pedal), a steering wheel, and other such components) are disposed in the passenger compartment 18 of the vehicle 10. The propulsion controller may be actuated or controlled by an operator of the vehicle 10, and the propulsion controller may be directly connected to corresponding components of the propulsion system, such as a throttle, a brake, a vehicle axle, a vehicle transmission, etc., respectively. In some embodiments, the propulsion controller may transmit a signal to a vehicle computer (e.g., via a 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 shafts of the wheel 22. When the vehicle 10 includes one or more electric motors, the vehicle battery and / or fuel cell provides energy to the electric motor to rotate the wheel 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 generally shown 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 shown 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 and the wheels 22 of the vehicle 10), 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, 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 an early life fault detection system and method, as described in more detail below.

[0036] In some embodiments, vehicle 10 may include a controller, such as Figure 1B100 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 alternative 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 (e.g., controller temperature, vehicle temperature, etc.), 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 steering 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 responds 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 described herein as using a wiring harness 220, the principles of the present disclosure may be implemented for systems including other types of paths between the power source 216 and the corresponding components as described above. In some examples, the motor 208, the controller 212, and / or other circuits may be collectively referred to as a "power pack." 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 controller having different connections between the controller and the power source 216, respective motors, etc., and various health status indicators of the electrical connections of the corresponding controllers, motors, etc. may be obtained (e.g., calculated, measured, etc.) according to the principles of the present disclosure.

[0043] The controller 212 receives various measurement signals from various sensors, including but not limited to one or more sensors 224 configured to generate measurement signals associated with the steering system 204, and vehicle status information (vehicle speed, mileage, temperature, etc.) received via 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 and / or calculated. For example, the motor speed ω_m may be calculated as a change in the motor position θ measured by the position sensor over a specified time interval. For example, the motor speed ω_m may be determined as a derivative of the motor position θ according to the formula 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 shown. 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 itself may not accurately indicate health, degradation, etc. 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] Regardless of whether the performance factor P increases overall, decreases overall, or both increases and decreases during the period 300, one or more measurements may have an expected range of values ​​during the period 300. For example, the resistance associated with the electrical connection (e.g., a resistance measured using one or more methods described herein) may have an expected range of values ​​during the period 300, including the initially measured resistance. Thus, resistance measurements outside of the expected range of values ​​may indicate one or more early life failures, the presence of one or more conditions that may lead to early life failures, and the like. The early detection systems and methods of the present disclosure are configured to detect early life failures based on various resistance measurements, including but not limited to the initially measured resistance. As used herein, "measurement" may refer to direct measurement and / or calculation, estimation, and the like of resistance based on one or more other variables.

[0048] In one example, early detection systems and methods according to the present disclosure are configured to implement process monitoring techniques to identify features that may lead to incorrect or non-optimal operation. For example, one or more control limits may be obtained based on observations and measurements of various characteristics of a given type or configuration of electrical connections. Early life failures may be detected based on the control limits and one or more measurements of the electrical connections (e.g., based on deviations between the one or more measurements and corresponding control limits).

[0049] Figure 4A An individual value and moving range (I-MR) graph of example sample observations / measurements of resistance values ​​400 (e.g., in milliohms) measured for various electrical connections (e.g., electrical connections corresponding to a power harness of a steering system as described above) is shown. In this example, the measurements may correspond to resistance measurements obtained prior to installing the power harness within a vehicle (e.g., in a manufacturing facility or environment).

[0050] In this example, for thirty observations (e.g., corresponding to thirty unique and different wiring harnesses / electrical connection systems), the average resistance is 2.587 milliohms, the example upper control limit (UCL) is 3.845 milliohms, and the example lower control limit (LCL) is 1.328 milliohms. The UCL and LCL can be calculated based on the resistance value 400. For example, the UCL and LCL can be calculated based on the standard deviation of the resistance value 400. In various examples, the UCL and LCL can be offset by one, two, three standard deviations, etc. relative to the average resistance. Variations in the UCL and LCL can also be adjusted for items that affect the consistency of resistance measurements, such as run to run, temperature, humidity, and / or any other factors that can affect resistance consistency. The UCL and LCL are shown relative to the maximum allowable resistance (e.g., upper specification limit or USL) of 5 milliohms (as shown by dashed line 404). Therefore, as shown in FIG. Figure 4A As shown, for the maximum allowed resistance of the example, each of the measured harnesses is within the tolerance range of the initial resistance defined between the UCL and the LCL.

[0051] Figure 4B Shown as Figure 4A 4 shows an I-MR graph of the same example sample observations / measurements for resistance value 400 shown in FIG, wherein an additional data point 408 (i.e., corresponding to the 31st measurement / line bundle) is outside the range defined by the UCL and LCL and is above the USL shown at 404. In other words, based on the data point 408 and the I-MR graph for the resistance value 400 shown in FIG. Figure 4B , the wiring harness corresponding to the measured resistance value at data point 408 may be identified as faulty (e.g., likely to cause an early life failure) by comparison between the control limits calculated for the data set shown in . In some examples, if data point 408 is greater than USL 404, then additional data point 408 may be considered faulty. The USL may be set so that resistances greater than the USL will immediately affect system performance, at a level that indicates common manufacturing defects for detection (e.g., a partially tightened bolt or a partially inserted connector), or at a level lower than would directly affect system performance, with foresight on how the system will age to ensure that under normal aging conditions, the resistance remains below a level that would functionally alter system performance.

[0052] Process stability, including process stability of measured resistance, can be highly temperature dependent. Thus, UCL and LCL can vary based on ambient temperature. Thus, in some examples, systems and methods according to the present disclosure can be configured to adjust measured resistance value 400 based on temperature. In other words, resistance value 400 can be temperature compensated.

[0053] Figure 4C 4 is a flow chart generally illustrating the steps of an example method 420 for detecting early life failures in electrical connections according to the principles of the present disclosure. The method 420 may be performed by one or more components of the systems 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 the method 420.

[0054] At 424, one or more resistance measurements associated with the wiring harness and / or corresponding electrical connections are obtained. For example, a resistance query can be provided to a power group (e.g., a motor, a controller / control circuit, etc.) or a similar system (e.g., one or more components of the system 200) coupled to the wiring harness. For example, the query is generated and communicated by a processor or controller of the diagnostic device. The system obtains one or more resistance measurements (e.g., as described herein, by supplying current to the motor and measuring the response of the motor) and provides the resistance measurements to the diagnostic device.

[0055] At 428, historical resistance data is obtained. For example, the historical resistance data may include resistance measurements obtained for the same type of wiring harness / electrical connection in the same manufacturing facility. The historical resistance data may be stored in a memory in a diagnostic device, in a remote device or server, in a cloud computing system, and the like. In addition, the USL may be derived from the maximum allowable resistance that provides the required power delivery capability (e.g., functional limit) for the system. For early life settings, the USL may be reduced from the functional limit to account for possible aging of conductive components (which results in increased resistance). Therefore, the USL for early life may be set lower to verify that the system is acceptable at the time of initial build, so that as the system ages and the resistance increases after a typical aging routine, the resistance remains below the functional limit throughout the life of the product and no performance degradation of the steering system is observed.

[0056] At 432, one or more limits (e.g., UCL, LCL, USL, etc.) are obtained or set (e.g., based on historical resistance data). At 436, method 420 (e.g., diagnostic device) selectively detects or predicts early life failure of the wiring harness based on a comparison between the one or more resistance measurements and the calculated control limits. For example, method 420 determines whether one or more resistance measurements are outside of a range defined by the obtained UCL, LCL, USL, or a combination thereof. One or more of the resistance measurements may indicate an early life failure of the wiring harness.

[0057] At 440, method 420 updates the stored data with the results of the early life fault detection. For example, stored historical data and / or data stored within the power pack or associated EPS system may be updated with the obtained resistance value and comparison results (e.g., by setting an indicator or flag in memory indicating that the wiring harness passed or failed the early life fault detection).

[0058] At 444, method 420 optionally generates and outputs a notification that the wiring harness failed early life fault detection. For example, the notification can be provided to a display of a diagnostic device. The notification can indicate one or more resistance measurements that caused the early life fault to be detected, prompt a user to repeat the early life fault detection of the wiring harness, recommend a repair or other remedial action, etc. In addition, based on the resistance level, the count of previous historical faults caused to the specific area based on similar readings, the notification can guide the operator to possible rework activities to effectively resolve the problem (e.g., using basic machine learning algorithms).

[0059] In other examples, a system (e.g., EPS system 200) can be configured to perform early life fault detection in accordance with the principles of the present disclosure after the power harness is installed in the vehicle (e.g., initially when the power harness is installed, during an early period of operation of the vehicle, etc.). In an example, resistance measurements are obtained each time the vehicle is cycled (e.g., each time the vehicle is turned on, off, etc.). In addition to the above, FIG. 4A to FIG. 4C In addition to or as an alternative to the process monitoring techniques described in , early life fault detection techniques implemented after installation in the vehicle and during operation of the vehicle may be performed. FIG. 4A to FIG. 4C The principles of the present disclosure described in the can be implemented in various levels of manufacturing (power pack, power pack and wiring harness, power pack and wiring harness and battery, etc.) and / or in vehicles at various levels of construction. The allowable resistance level can be defined differently at different manufacturing levels.

[0060] For example, a power pack of a steering system (or other device / subsystem coupled to an electrical harness) may have one or more design constraints, such as a maximum allowable incoming resistance from a power source. The power pack is designed to provide a desired torque output in a system defined by the same design constraints. Thus, the early life fault detection systems and methods of the present disclosure detect whether a system including the power pack exceeds a maximum allowable incoming resistance (e.g., one or more resistance thresholds based on the maximum allowable incoming resistance).

[0061] In one example, an early life fault detection system (e.g., as implemented by system 200) monitors the resistance of a wiring harness (e.g., by periodically obtaining resistance measurements of electrical connections as described herein) and compares the resistance to a control limit (e.g., a maximum allowable resistance). In some examples, the maximum allowable resistance is significantly greater than a typical USL (e.g., for a USL of 5 milliohms, the maximum allowable resistance is 30 milliohms). Because the measured resistance and other measurements can vary during a stabilization period as described above, the system can store a first flag or other indicator in response to one or more initial resistance measurements exceeding a resistance threshold corresponding to the maximum allowable resistance. In other words, an initial resistance measurement that exceeds a resistance threshold may not necessarily indicate an early life fault because the measured resistance may increase and / or decrease during a stabilization period.

[0062] Thus, the system can be configured to store a second flag or indicator in response to one or more resistance measurements obtained after a predetermined period of time (e.g., after a predetermined period of time setting, after a predetermined number of sample measurements, etc.) exceeding a resistance threshold. As an example, the system can be configured to compare a single resistance measurement obtained after a predetermined period of time with the resistance threshold. As another example, the system can be configured to compare an average of two or more resistance measurements obtained after a predetermined period of time with the resistance threshold.

[0063] The system can store multiple marks or indicators based on corresponding calculations and measurements. For example, a first indicator can be stored in response to one or more resistance measurements exceeding a resistance threshold, a second indicator can be stored in response to one or more resistance measurements obtained after a predetermined period exceeding a resistance threshold, etc. Various indicators can be stored in response to a specific resistance measurement sample exceeding a resistance threshold (e.g., the 50th resistance measurement, the 100th resistance measurement, etc.), an average resistance measurement for a predetermined time period (e.g., the average of the 1st to 50th resistance measurements, the average of the 51st to 100th resistance measurements, etc.). The resistance thresholds for various indicators can be the same or different. For example, the resistance threshold can increase with time / number of samples. In some examples, the initial resistance test in a vehicle (e.g., a vehicle in use) can be performed for various time limits, but the rate of change compared to the expected rate of change of stability in the connection system can also be considered. A large deviation from the expected stability can indicate aging or stability in an unplanned and potentially unpredictable manner, and a mark can be set to indicate an early life failure problem. Thus, the deviation can be compared to a known common stable curve and if the deviation exceeds a threshold, a flag can be set.

[0064] Figure 5 1 is a flow chart generally illustrating the steps of an example method 500 for detecting early life faults in electrical connections after installation and operation in a vehicle according to the principles of the present disclosure. The method 500 may be performed by one or more components of the systems 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 the method 500.

[0065] At 504, one or more resistance measurements associated with the wiring harness and / or corresponding electrical connections are obtained. For example, a resistance query may be provided to a power group (e.g., a motor, a controller / control circuit, etc.) or a similar system (e.g., one or more components of system 200) connected to the wiring harness. For example, the query is generated and transmitted by a processor or controller (e.g., controller 212) of the power group. In response to the resistance query, one or more resistance measurements are obtained (e.g., as described herein, by supplying current to the motor and measuring the response of the motor). In some examples, the resistance query is automatically generated (e.g., periodically, conditionally, when the vehicle is turned on or off, etc.). Each resistance measurement result can be stored as historical resistance data (e.g., stored in a memory of the controller 212 or another component of the vehicle, stored in a remote server or cloud computing system, etc.). In an example, the one or more resistance measurements obtained at 504 include a first (1st) resistance measurement result obtained after the power harness is installed in the vehicle.

[0066] At 508, the method 500 (e.g., the controller 212) determines whether the one or more resistance measurements exceed a first resistance threshold. The first resistance threshold corresponds to a calibratable variable (e.g., between 5 milliohms and 500 milliohms). At 512, based on determining whether the one or more resistance measurements exceed the first resistance threshold, a first indicator is stored. For example, in response to determining that one or more of the resistance measurements exceed the first resistance threshold, the first indicator includes data including, but not limited to, a timestamp of the one or more resistance measurements, a value of the one or more resistance measurements, and an indication that the first resistance threshold is exceeded.

[0067] At 516 , method 500 continues to obtain resistance measurements while operating the vehicle (eg, periodically, at each on / off cycle of the vehicle, etc.).

[0068] At 520, method 500 calculates a first average resistance of the first range of resistance measurements. For example, the first average resistance corresponds to resistance measurement samples 1 to m (where m is an integer greater than 1). In the example, m=50. Although described with respect to a particular number of samples, in other examples, the first range of resistance measurements may correspond to measurements taken within a predetermined time period (e.g., one month, two months, etc.).

[0069] At 524, method 500 selectively stores a second indicator based on determining whether the first average resistance exceeds a second resistance threshold. The second resistance threshold may be the same as or different from the first resistance threshold. For example, method 500 determines whether the first average resistance exceeds the second resistance threshold. Based on determining whether the first average resistance exceeds the second resistance threshold, the second indicator is stored. For example, in response to determining that the first average resistance exceeds the second resistance threshold, the second indicator includes data including, but not limited to, a timestamp of the first average resistance, a value of the first average resistance, and an indication that the second resistance threshold is exceeded.

[0070] At 528, method 500 calculates a second average resistance of the second range of resistance measurements. For example, the second average resistance corresponds to resistance measurement samples m to n (where n is an integer greater than m). In the example, n=100. Although described with respect to a particular number of samples, in other examples, the second range of resistance measurements may correspond to measurements taken within a predetermined time period (e.g., one month, two months, etc.).

[0071] At 532, method 500 selectively stores a third indicator based on determining whether the second average resistance exceeds a third resistance threshold. The third resistance threshold may be the same as or different from the first resistance threshold and the second resistance threshold. For example, method 500 determines whether the second average resistance exceeds the third resistance threshold. Based on determining whether the second average resistance exceeds the third resistance threshold, the third indicator is stored. For example, in response to determining that the second average resistance exceeds the third resistance threshold, the third indicator includes data including, but not limited to, a timestamp of the second average resistance, a value of the second average resistance, and an indication that the third resistance threshold is exceeded.

[0072] At 536 , an nth resistance measurement is obtained. The nth resistance measurement may correspond to a particular number of samples (e.g., 100), a particular predetermined period of time, etc. For example, n may be a value selected to be after a stabilization period of the vehicle and / or electrical connection.

[0073] At 540, the method 500 selectively stores a fourth indicator based on determining whether the nth resistance measurement exceeds a fourth resistance threshold. The fourth resistance threshold may be the same as or different from the first resistance threshold, the second resistance threshold, and the third resistance threshold. For example, the method 500 determines whether the nth resistance measurement exceeds the fourth resistance threshold. Based on determining whether the nth resistance measurement exceeds the fourth resistance threshold, the fourth indicator is stored. For example, in response to determining that the nth resistance measurement exceeds the fourth resistance threshold, the fourth indicator includes data including, but not limited to, a timestamp of the nth resistance measurement, a value of the nth resistance measurement, and an indication that the fourth resistance threshold is exceeded.

[0074] At 544, method 500 optionally generates and outputs a notification of the detection of an early life fault based on one or more of the first indicator, the second indicator, the third indicator, and the second indicator. The notification may indicate one or more resistance measurements that led to the detection of the early life fault, a recommended repair or other remedial action, etc. The notification may be provided to a driver or user, a manufacturer, a dealer, a maintenance facility, etc. As an example, the notification is provided to a 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. For example, the notification (e.g., a check engine light or other indicator) may indicate that the vehicle requires maintenance, recommending that the driver or user schedule maintenance to check and repair electrical connections, replace electrical connections, etc.

[0075] The corresponding data may be sent to a remote server or cloud computing system for remote analysis, to a local diagnostic tool (eg, an OBDII reader or other diagnostic device) attached to the vehicle, and the like.

[0076] In another example, 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, in response to detecting an early life failure, various parameters (e.g., current provided to the motor) may be controlled to minimize additional wear on the electrical connections and avoid failure.

[0077] In one example, the method 500 may generate a notification in response to only two or more of the indicators being stored, in response to a predetermined combination of indicators being stored, etc. For example, if the first indicator is stored but the second indicator, the third indicator, and the fourth indicator are not stored, then no notification may be generated. In other words, only the first indicator being stored may indicate that the initial resistance measurement exceeds the first resistance threshold, but the resistance measurement no longer exceeds the corresponding resistance threshold after a stable period. Conversely, if the first indicator and the second indicator are not stored, but the third indicator and the fourth indicator are stored, then a notification may be generated. In other words, the third indicator and the fourth indicator being stored may indicate that the measured resistance increases significantly for samples m to n, which may indicate an early life failure.

[0078] 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.

[0079] 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 specific 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 articles "one" and "a" 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 embodiment" throughout the text is not intended to represent the same embodiment or specific implementation, unless so described.

[0080] The specific implementation of the systems, algorithms, methods, instructions, etc. described herein may 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.

[0081] As used herein, the term module may include: a packaged functional hardware unit designed for use with other components; a set of instructions executable by a controller (e.g., a processor executing 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); an electrical circuit; a digital logic circuit; an analog circuit; a combination of discrete circuits; a gate; and other types of hardware; or a combination thereof. In other embodiments, a module may include a memory that stores instructions that are executable by a controller to implement the features of the module.

[0082] 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.

[0083] 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.

[0084] 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 detecting early life failures of electrical connections of a power harness of a steering system of a vehicle, the method comprising using a processor configured to execute instructions: obtaining a resistance measurement associated with an electrical power delivery system including the electrical connection; Get historical resistance data; obtaining at least one limit, wherein the at least one limit is obtained based on at least one of the historical resistance data and a functional limit; detecting an early life failure of the electrical connection based on a comparison of the resistance measurement to the at least one limit; as well as In response to detecting the early life failure, at least one action is performed.

2. The method according to claim 1, wherein: Obtaining the resistance measurement includes obtaining the resistance measurement prior to installing the power harness in the vehicle.

3. The method according to claim 1, wherein: The at least one limit is an upper limit.

4. The method according to claim 1, further comprising: The resistance measurement is obtained 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.

5. The method according to claim 4, wherein: The sinusoidal current is a current that does not generate torque.

6. The method according to claim 1, wherein: The steering system is an electric power steering system, and the electrical connection is an electrical connection between a motor of the electric power steering system and a power source.

7. The method according to claim 1, wherein: Performing the at least one action includes at least one of the following: responsive to detecting the early life fault, generating and displaying an indicator; as well as In response to detecting the early life fault, at least one operating parameter of the vehicle is controlled.

8. A method for detecting early life failures of electrical connections of a power harness of a steering system of a vehicle, the method comprising using a processor configured to execute instructions: after installing the power harness in the vehicle, obtaining a first resistance measurement associated with the electrical connection; subsequent to the first resistance measurement, obtaining a second resistance measurement associated with the electrical connection; detecting an early life failure of the electrical connection based on at least one of (i) a comparison between the first resistance measurement and a first resistance threshold and (ii) a comparison between the second resistance measurement and a second resistance threshold; and In response to detecting the early life failure, at least one action is performed.

9. The method according to claim 8, wherein: Obtaining the second resistance measurement result includes obtaining the second resistance measurement result within a predetermined period of time or a predetermined number of measurement samples after obtaining the first resistance measurement result.

10. The method according to claim 9, wherein: Obtaining the second resistance measurement result includes: obtaining a first average value of a plurality of first resistance measurement results within a first time period after obtaining the first resistance measurement result.

11. The method according to claim 10, further comprising: obtaining a third resistance measurement associated with the electrical connection after the second resistance measurement, wherein obtaining the third resistance measurement comprises obtaining a second average of a plurality of second resistance measurements during a second time period after the first time period; and The early life failure of the electrical connection is detected further based on a comparison between the third resistance measurement and a third resistance threshold.

12. The method according to claim 11, wherein: The second time period includes the first time period and / or overlaps with the first time period.

13. The method according to claim 11, wherein: The second time period does not overlap with the first time period.

14. The method according to claim 11, further comprising: obtaining, after the third resistance measurement, a fourth resistance measurement associated with the electrical connection, wherein the fourth resistance measurement corresponds to a predetermined number of measurement samples after the first resistance measurement; and The early life failure of the electrical connection is detected further based on a comparison between the fourth resistance measurement and a fourth resistance threshold.

15. A system for detecting early life failures of electrical connections of a power harness of a steering system of a vehicle, the system comprising: at least one sensor configured to make a resistance measurement associated with the electrical connection; and The controller is configured as: after installing the power harness in the vehicle, obtaining a first resistance measurement associated with the electrical connection; subsequent to the first resistance measurement, obtaining a second resistance measurement associated with the electrical connection; detecting an early life failure of the electrical connection based on at least one of (i) a comparison between the first resistance measurement and a first resistance threshold and (ii) a comparison between the second resistance measurement and a second resistance threshold; and In response to detecting the early life failure, at least one action is performed.

16. The system of claim 15, wherein: Obtaining the second resistance measurement result includes obtaining the second resistance measurement result within a predetermined period of time or a predetermined number of measurement samples after obtaining the first resistance measurement result.

17. The system of claim 16, wherein: Obtaining the second resistance measurement result includes: obtaining a first average value of a plurality of first resistance measurement results within a first time period after obtaining the first resistance measurement result.

18. The system of claim 17, wherein: The controller is also configured to: obtaining a third resistance measurement associated with the electrical connection after the second resistance measurement, wherein obtaining the third resistance measurement comprises obtaining a second average of a plurality of second resistance measurements during a second time period after the first time period; and The early life failure of the electrical connection is detected further based on a comparison between the third resistance measurement and a third resistance threshold.

19. The system of claim 18, wherein: The second time period includes the first time period and / or overlaps with the first time period.

20. The system of claim 18, wherein: The controller is also configured to: obtaining, after the third resistance measurement, a fourth resistance measurement associated with the electrical connection, wherein the fourth resistance measurement corresponds to a predetermined number of measurement samples after the first resistance measurement; and The early life failure of the electrical connection is detected further based on a comparison between the fourth resistance measurement and a fourth resistance threshold.

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