System and method for diagnosing a parking function of an in-wheel electric motor

Abstract

A method for diagnosing a parking function in a vehicle including a plurality of in-wheel motors, each in-wheel motor including first and second planetary gear sets, each of the first and second planetary gear sets including selectively engaging each of the plurality of in-wheel motors on a computing device, the method includes receiving a plurality of in-wheel motors from a first planetary gear set and a second planetary gear set to place each in-wheel motor into a parked state, engaging a respective locking mechanism of each in-wheel motor, determining whether a respective one of the plurality of in-wheel motors maintains the parked state when each of the first and second planetary gear sets is engaged and the respective locking mechanism is engaged, and locking the respective one of the plurality of in-wheel motors when the respective one of the plurality of in-wheel motors maintains the parked state. And operating the vehicle in a selected one of a plurality of operating modes, the selected operating mode being based on the determination whether a respective one of the plurality of in-wheel motors remains in the parked state.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 348,200, filed on June 2, 2022, and priority to U.S. Application No. 18 / 204,340, filed on May 31, 2023. The entire disclosures of the above applications are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to electrical devices, such as electric propulsion systems, and more particularly to a method for diagnosing a parking function of an electric propulsion system of an electric vehicle. Background Art

[0004] This section provides a general summary of background information, and the comments and examples provided in this section are not necessarily prior art to the present disclosure.

[0005] Various drivetrain systems in cars, trucks, and certain off-highway applications receive power from a central prime mover and distribute it to at least one wheel using mechanical devices such as transmissions, transaxles, propeller shafts, and drive shafts. These configurations work well when the prime movers are large or heavy, such as various internal combustion engines ("ICE") and centralized electric axles.

[0006] According to certain automotive standards, specifically FMVSS114 and ISO26262:2018, both traditional ICE and electric vehicles require a transmission PARK state. In relation to FMVSS114, during compliance testing, the National Highway Traffic Safety Administration (NHTSA) "will attempt to move the transmission out of the 'park' position at each ignition position without depressing the vehicle's brake pedal. If the transmission can be moved out of the park position without depressing the brake pedal, it will be considered a significant non-compliance finding."

[0007] Internal combustion engine (ICE) and centralized electric axle drive vehicles achieve the transmission park state through a separate park pawl mechanism that is engaged to prevent the gears / shafts within the transmission from moving. Originally, these mechanisms were cable / spring based, but more current vehicles control the transmission park function through some type of electromechanical drive system. Electromechanical drive systems often contain sensing elements to ensure that the vehicle and operator are truly aware of the state of the transmission. Summary of the invention

[0008] A method for diagnosing a parking function in a vehicle, the vehicle including a plurality of in-wheel motors, each in-wheel motor including a first and a second planetary gear set, the method comprising, on a computing device: selectively engaging the first and second planetary gear sets of each of the plurality of in-wheel motors to place the plurality of in-wheel motors in a park state, engaging a respective locking mechanism of each of the plurality of in-wheel motors, determining whether a corresponding one of the plurality of in-wheel motors maintains the park state when each of the first and second planetary gear sets are engaged and the respective locking mechanism is engaged, and operating the vehicle in a selected one of a plurality of operating modes, the selected operating mode being based on the determination whether the corresponding one of the plurality of in-wheel motors maintains the park state.

[0009] In other features, the method further includes: operating the vehicle in a first operating mode in response to determining that each of the plurality of in-wheel motors maintains the park state; operating the vehicle in a second operating mode in response to determining that at least one but not all of the plurality of in-wheel motors maintains the park state; and operating the vehicle in a third operating mode in response to determining that none of the plurality of in-wheel motors maintains the park state. Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes: de-energizing at least one solenoid, the at least one solenoid being configured to, when energized, engage the first and second planetary gear sets with a clutch assembly. Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes: de-energizing two solenoids, the two solenoids being respectively configured to, when energized, engage the first and second planetary gear sets with the clutch assembly. The first and second planetary gear sets correspond to first and second drive gears, respectively.

[0010] In other features, the vehicle includes two of the plurality of in-wheel motors. The vehicle includes more than two of the plurality of in-wheel motors. The respective locking mechanisms each include a pin configured to selectively engage a shift fork to prevent movement of the shift fork. The respective locking mechanisms include a single pin configured to selectively engage one or more shift forks to prevent movement of the one or more shift forks.

[0011] A computing device is configured to execute instructions stored in a memory that, when executed, cause the computing device to perform a plurality of steps for diagnosing a parking function in a vehicle, the vehicle including a plurality of in-wheel motors, each of the plurality of in-wheel motors including first and second planetary gear sets. The plurality of steps include selectively engaging each of the first and second planetary gear sets of each of the plurality of in-wheel motors to place each of the plurality of in-wheel motors in a park state, engaging a respective locking mechanism of each of the plurality of in-wheel motors, determining whether a corresponding one of the plurality of in-wheel motors maintains the park state when each of the first and second planetary gear sets is engaged and the respective locking mechanism is engaged; and operating the vehicle in a selected one of a plurality of operating modes, the selected operating mode being based on the determination whether the corresponding one of the plurality of in-wheel motors maintains the park state.

[0012] In other features, the plurality of steps further include: operating the vehicle in a first operating mode in response to determining that each of the plurality of in-wheel motors maintains the park state; operating the vehicle in a second operating mode in response to determining that at least one but not all of the plurality of in-wheel motors maintains the park state; and operating the vehicle in a third operating mode in response to determining that none of the plurality of in-wheel motors maintains the park state. Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes: de-energizing at least one engagement mechanism, the at least one engagement mechanism being configured to, when energized, cause the first and second planetary gear sets to engage a clutch assembly. Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes: de-energizing two engagement mechanisms, the two engagement mechanisms being respectively configured to, when energized, cause the first and second planetary gear sets to engage the clutch assembly. The first and second planetary gear sets correspond to first and second drive gears, respectively.

[0013] In other features, the vehicle includes two of the plurality of in-wheel motors. The vehicle includes more than two of the plurality of in-wheel motors. The respective locking mechanisms each include a pin configured to selectively engage a shift fork to prevent movement of the shift fork. The plurality of steps also include using data from a plurality of sensors and historical vehicle operating data to update calibration data located in a memory to dynamically adjust thresholds for determining whether the first and second planetary gear sets are engaged or disengaged during a useful life of the vehicle. The plurality of steps also include using the updated calibration data for vehicle propulsion operations and for confirming an operating condition of the parked state.

[0014] Other advantages will be appreciated from the following more detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are for illustrative purposes only of selected aspects and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0016] 1A and 1B illustrate an example park function implementation using a parking pawl mechanism.

[0017] Figure 2A A simplified example of an electric vehicle with an in-wheel motor having an integrated transmission configuration is shown.

[0018] Figure 2B A block diagram of an example computing device configured to implement the functionality of the systems and methods described herein is shown.

[0019] Figure 2C An example implementation of a planetary gear set is shown.

[0020] Figure 2D Shows Figure 2C A portion of a shift fork of the planetary gear set shown in ; and

[0021] Figure 3 Several steps of an exemplary method for diagnosing a parking function of each in-wheel motor of an electric vehicle according to the present disclosure are shown. DETAILED DESCRIPTION

[0022] 1A and 1B illustrate an example parking function implementation using a parking pawl 100 located within a transmission 102 (e.g., an ICE vehicle). The parking pawl 100 moves into engagement with a dedicated parking gear 104 (as shown in FIG. 1A ) and out of engagement with a dedicated parking gear 104 (as shown in FIG. 1B ). In some examples, the electromechanical device 106 rotates clockwise or counterclockwise for such engagement and disengagement, respectively. In other examples, the electromechanical device 106 may rotate in only one direction but is configured to determine whether it is in an engaged or disengaged position. When rotating clockwise and the gear is in an engaged position as shown in FIG. 1A , the electromechanical device 106 disengages from the parking pawl 100 and allows a biasing element (e.g., a spring 108) to bias the parking pawl 100 away from the gear 104. Conversely, when rotating counterclockwise and the gear 104 is in a disengaged position as shown in FIG1B , the electromechanical device 106 biases the parking pawl 100 toward the gear 104. Compliance testing can be performed by parking the vehicle on a specified slope to ensure that the parking pawl 100 does not disengage ("pop out") when the vehicle is facing uphill or downhill.

[0023] Typically, the parking pawl 100 and the parking gear 104 are configured so that the vehicle does not have to be 100% stationary to begin the engagement process. For example, the parking pawl 100 may jump over the teeth 110 of the parking gear 104 until the vehicle slows down to such an extent that the parking pawl 100 is engaged with the parking gear 104 (i.e., disposed between adjacent teeth 110) and there is not enough force to push the engagement mechanism 112 of the parking pawl 100 out from between the teeth 110. Attempting to engage the parking pawl 100 while the vehicle is moving may result in a loud noise. In some examples, additional electronic sensing capabilities may be added to the engagement mechanism 112 for diagnostic purposes (e.g., to determine possible damage to the parking pawl 100 or the teeth 110 on the parking gear 104).

[0024] The parking function operation described above in Figures 1A and 1B may not be feasible or effective in some types of vehicles and motor-based propulsion configurations, so more attention is directed to alternative arrangements that can provide better environmental performance, eliminate mechanical drivetrain components, and result in lighter vehicles, providing more space for passengers and payload. For example, an "on wheel", "in-wheel" or "near-wheel" motor configuration (all considered in-wheel or wheel-end electric motors for the purpose of this disclosure) is an example alternative arrangement of an ICE or centralized electric axle prime mover, which distributes a prime mover function to each or some of the multiple wheels through one or more electric propulsion systems arranged on, in or near the multiple wheels. Specifically, when an electric vehicle solution is implemented using in-wheel motors (IWMs), the electric vehicle can have two such motors in a rear-wheel or front-wheel drive configuration, or four IWMs in an all-wheel drive configuration. Other configurations with different numbers of IWMs are possible, with a minimum of one IWM and no maximum limit.

[0025] The system and method according to the present disclosure implements an integrated functional safety and diagnostic method for implementing a parking function / transmission parking state in a vehicle having an in-wheel motor / transmission configuration. For example, the system according to the present disclosure is configured to simultaneously confirm the health status of the parking function and provide a soft safe state (e.g., a state indicating that the electric vehicle can still operate but with limited functions) and a hard safe state (e.g., a state indicating that the vehicle should not operate) based on the health status of the multiple in-wheel motors. These functions cannot be implemented in the above-mentioned single parking pawl-based architecture.

[0026] For example, an in-wheel motor according to the present disclosure has multiple gear states (e.g., park, reverse, neutral, drive, forward 2 (D2), and forward 1 (D1)), which are set by the engagement or disengagement of a dog clutch controlled by two solenoids (S1 / S2). In another embodiment, an alternative engagement mechanism, such as a magnetic coil, is used to control engagement / disengagement. An example of such an in-wheel electric motor is disclosed in the applicant's U.S. application No. 17 / 575,677 (published as U.S. Patent No. 11,590,840 on February 28, 2023), the entire disclosure of which is incorporated herein by reference. When both solenoids (S1 / S2) (or other actuator control mechanisms) are engaged, the rotation of a planetary gear is locked, thereby preventing a single wheel from moving and establishing the parking state, advantageously without the need for additional components to establish the parking function (e.g., a parking pawl, parking gear, cable, motor, spring, etc.).

[0027] The systems and methods disclosed herein utilize built-in redundancy associated with the parallel aspects of the IWM arrangement (i.e., dual IWM, quad IWM, etc.) in an electric vehicle to determine soft and hard safety states. For example, by utilizing an IWM shutdown at vehicle startup, a healthy parking mechanism state can be determined at each wheel end, thereby enabling soft and hard safety states for the system and providing diagnostic information to the vehicle / operator. In a similar manner, based on sensor diagnostics, the health state and the need for a soft or hard safety state can be determined while the vehicle is running and before the operator stops the vehicle and executes a PARK command. The information utilized in this solution can be used for self-learning to adjust operations due to component wear during the service life of the electric vehicle. Accordingly, the systems and methods described herein can achieve safe operation, extended operation when a partial fault is detected, and implement self-learning functions to support dynamic calibration.

[0028] Several example aspects of the diagnostic methods and corresponding algorithms associated with the parking function of the IWM are described in more detail below. Each example embodiment is provided so that the present disclosure is comprehensive and fully conveys the scope, features, and advantages of the inventive concepts to those skilled in the art. To this end, a large number of specific details are set forth, such as examples of specific components, devices, mechanisms, flow charts, or process steps associated with the algorithms and methods, to provide a comprehensive understanding of each embodiment associated with the present disclosure. However, as will be appreciated by those skilled in the art, not all of the specific details described herein need to be adopted, and the example embodiments may be embodied in a variety of different forms and therefore should not be interpreted or construed as limiting the scope of the present disclosure. In addition, the methods described in more detail below are applicable to both partially and fully electric vehicles without departing from the scope of the present subject disclosure.

[0029] Figure 2AA simplified example of an electric vehicle 200 having an in-wheel motor configuration is shown. In this example, each wheel 204 of the vehicle 200 includes a respective in-wheel motor 206 (i.e., a four-wheel IWM). The motor 206 receives power from a battery system 208 (e.g., through one or more inverters 210, which are configured to convert direct current (DC) power to alternating current (AC) power to control the motor 206). A motor / transmission controller 212 controls the supply of power from the battery system 208 to the plurality of in-wheel motors 206. For example, the motor / transmission controller 212 receives torque requests and / or other inputs from a driver and other vehicle systems (e.g., a cruise control system, an autonomous vehicle system, etc.) through a vehicle controller 214, and controls motor torque accordingly. One or more of the motor / transmission controller 212, the vehicle controller 214, and / or other controllers of the vehicle 200 may be configured to implement the functionality of the systems and methods of the present disclosure, as described in more detail below.

[0030] Figure 2B A block diagram of an example computing device 220 configured to (and / or including circuitry configured to) implement the functionality of the systems and methods described herein is shown. For example, the computing device 220 may be implemented or implemented by the motor / transmission controller 212, the vehicle controller 214, and / or other controllers of the vehicle, individually or collectively. The systems described herein may implement a single computing device, multiple computing devices, etc. configured to independently and / or collectively perform the functionality associated with the systems and methods disclosed herein.

[0031] The computing device 220 may include control circuitry 224, which may be, for example, one or more processors or processing devices, a central processing unit processor (CPU), an integrated circuit or any suitable computing or computational device, an operating system 226, a memory 228, executable code 230, input devices or circuits 232, and output devices or circuits 234. The control circuitry 224 (or one or more controllers or processors, possibly across multiple units or devices) may be configured to implement the functions of the systems and methods described herein. According to embodiments of the present disclosure, more than one computing device 220 may be included in a system, and one or more computing devices 220 may serve as components of the system. The various components of the computing device 220 may be implemented using the same or different circuits, the same or different processors or processing devices, etc.

[0032] The operating system 226 may be or may include any code segment (e.g., a code segment similar to the executable code 230 described herein) that is designed and / or configured to perform tasks involving coordination, scheduling, arbitration, supervision, control, or otherwise managing the operation of the control circuit 224, such as scheduling the execution of software programs or tasks or enabling software programs or other hardware modules or units to communicate. The operating system 226 may be a commercial operating system. It is worth noting that the operating system 226 may be an optional component (e.g., in some embodiments, the system may include a computing device that does not require or include the operating system 226). For example, a computer system may be or may include a microcontroller, an application specific circuit (ASIC), a field programmable array (FPGA), a network controller (e.g., a CAN bus controller), an associated transceiver, a system on a chip (SOC), and / or any combination thereof that may be used without an operating system.

[0033] The memory 228 may be or may include, for example, a random access memory (RAM), a read-only memory (ROM), a dynamic RAM (DRAM), a synchronous DRAM (SD-RAM), a double data rate (DDR) memory chip, a flash memory, a volatile memory, a non-volatile memory, a cache, a buffer, a short-term memory unit, a long-term memory unit, or other suitable memory unit or storage unit. The memory 228 may be or may include a plurality of possibly different memory units. The memory 228 may be a computer or processor non-transitory readable medium, or a computer non-transitory storage medium, such as RAM.

[0034] The executable code 230 may be any executable code, such as an application, a program, a process, a task, or a script. The executable code 230 may be executed by the control circuit 224, possibly under the control of the operating system 226. Although only a single executable code 230 is shown for clarity, a system according to some embodiments of the present disclosure may include multiple executable code segments similar to the executable code 230, which may be loaded into the memory 228 and cause the control circuit 224 to perform the methods described herein. Where applicable, the terms "process" and "executable code" may be used interchangeably herein. For example, verification, validity, and / or authentication of a process may refer to verification, validity, and / or authentication of an executable code.

[0035] In some examples, the memory 228 may include a non-volatile memory having the storage capacity of a storage system. In other examples, the computing device 220 may include a storage system or communicate with a storage system. Such a storage system may include, for example, flash memory as known in the art, internal or embedded memory of a microcontroller or chip as known in the art, a hard drive, a recordable CD (CD-R) drive, a Blu-ray Disc (BD), a universal serial bus (USB) device, or other suitable removable and / or fixed storage unit. Content may be stored in the storage system and loaded from the storage system into the memory 228, where the control circuit 224 may process the content.

[0036] The input circuit 232 may be or may include any suitable input device, component or system, for example, a physical sensor such as an accelerometer, a thermometer, a microphone, an analog-to-digital converter, a detachable keyboard or keypad, a mouse, etc. The output circuit 234 may include one or more (possibly detachable) displays or monitors, motors, servo motors, speakers, high-side drivers, low-side drivers, and / or any other suitable output devices. Any applicable input / output (I / O) device may be connected to the control circuit 224. For example, a wired or wireless network interface card (NIC), a universal serial bus (USB) device, a JTAG interface, or an external hard drive may be included in the input circuit 232 and / or the output circuit 234. It can be appreciated that any suitable number of input devices and output devices may be operably connected to the control circuit 224. For example, a technician or engineer may use the input circuit 232 and the output circuit 234 to connect to the control circuit 224, update software, etc.

[0037] Embodiments may include, for example, a computer or processor non-transitory readable medium, or a computer or processor non-transitory storage medium, such as a memory, a disk drive, or a USB flash drive, which encodes, includes, or stores instructions (e.g., computer executable instructions that, when executed by a processor or controller, perform the methods disclosed herein), a storage medium, such as memory 228, computer executable instructions such as the executable code 230, and a controller such as the control circuit 224.

[0038] The storage medium may include, but is not limited to, any type of disk, including magneto-optical disks, semiconductor devices such as read-only memory (ROM), random access memory (RAM), such as dynamic RAM (DRAM), erasable programmable read-only memory (EPROM), flash memory, electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, or any type of medium suitable for storing electronic instructions, including programmable storage devices.

[0039] Embodiments of the present disclosure may include multiple components, such as, but not limited to, multiple central processing units (CPUs) or any other suitable multi-purpose or special-purpose processors or controllers (e.g., controllers similar to the control circuit 224), multiple input units, multiple output units, multiple memory units, and multiple storage units. The system may also include other suitable hardware components and / or software components. In some embodiments, the system may include or may be, for example, a personal computer, a desktop computer, a mobile computer, a laptop computer, a notebook computer, a terminal, a workstation, a server computer, a personal digital assistant (PDA) device, a tablet computer, a network device, or any other suitable computing device.

[0040] In some embodiments, the system may include or may be, for example, a plurality of components including respective central processing units, for example, a plurality of CPUs as described above, a plurality of CPUs embedded in an onboard system or network, a plurality of chips, FPGAs or SOCs, microprocessors, transceivers, microcontrollers, a plurality of computers or network devices, any other suitable computing device and / or any combination thereof. For example, the system described herein may include one or more devices such as the control circuit 224.

[0041] Figure 2C An example implementation of a planetary gear set 240 (e.g., of one of the plurality of in-wheel motors 206) is schematically shown. The gear set 240 includes two planetary gear assemblies 242 and 244 configured to transmit rotational power / motion to an output shaft 246 (e.g., an output shaft coupled to the wheel 204). A clutch assembly 248 is configured to selectively mechanically engage one or both of the gear assemblies 242 and 244 with the output shaft 246 (e.g., in response to commands from the motor / transmission controller 212 and / or the vehicle controller 214). In one embodiment, a first solenoid 252 is energized to mechanically engage the clutch assembly 248 (e.g., a first clutch of the clutch assembly 248) with the gear assembly 242, which may correspond to a first drive gear (e.g., LOW). A second solenoid 254 is energized to mechanically engage the clutch assembly 248 (e.g., a second clutch of the clutch assembly 248) with the gear assembly 244, which may correspond to a second drive gear (e.g., HIGH). When both solenoids 252 and 254 are not energized, neither of the gear assemblies 242 and 244 is engaged with the clutch assembly 248, which may correspond to a neutral gear. Although described herein as solenoids 252 and 254, other electrical, mechanical, or motor engagement mechanisms may also be implemented.

[0042] However, when both the solenoids 252 and 254 are energized, both the gear assemblies 242 and 244 engage the clutch assembly 248, which corresponds to a park state. For example, as described in more detail in incorporated U.S. Patent No. 11,590,840, engaging both the gear assemblies 242 and 244 simultaneously with the respective clutches of the clutch assembly 248 locks the planetary gear set 240 in place and prevents the corresponding wheel 204 from moving. In other words, the systems and methods according to the present disclosure operate in accordance with a gear set 240 configured to achieve a park state without the need for additional gears or parking gears or parking pawls. In addition, since each wheel 204 and corresponding motor 206 each have the configuration described, any motor 206 can be independently controlled to achieve a park state. Therefore, for the vehicle 200, if at least one IWM 206 is fully functional, the same level of parking functionality as in the system using a parking pawl described above in FIGS. 1A and 1B can be achieved. However, when more than one IWM 206 is fully functional, the park function of the vehicle 200 may achieve a level of redundancy not found in the above-described systems using the park pawl configuration. Finally, when the vehicle 206 includes more than one IWM 206 and at least one IWM 206 is fully functional but at least one IWM 206 is not fully functional, then the park function may be considered operational but operating in a SOFT safety state mode.

[0043] In some examples, the clutches of the clutch assembly 248 may be actuated by energizing the solenoids 252 / 254 , thereby causing translational movement of a shift mechanism such as a piston, shift fork, etc. Figure 2D 2 shows a portion of a shift fork 260. When the corresponding solenoid is energized, the shift fork 260 moves in a first direction (e.g., as indicated by arrow 262) to engage the corresponding clutch with a gear assembly. Conversely, when the solenoid is not engaged, the shift fork 260 moves in a second direction (e.g., as indicated by arrow 264) to disengage the clutch. For example, a spring or other mechanical biasing element is used to bias the shift fork 260, a corresponding piston, etc. in the second direction. Therefore, when the solenoid is not energized, a default position of the shift fork 260 corresponds to disengaging the clutch assembly from the corresponding gear assembly.

[0044] According to the present disclosure, the shift fork 260, the solenoids 252, 254 and / or another mechanical element can be placed in a locked state to prevent disengagement. As an example, the shift fork 260 may include a slot 268. A pin 270 can be selectively actuated (e.g., in response to the motor / transmission controller 212, the vehicle controller 214, etc.), thereby causing the pin 270 to be inserted into the slot 268. The pin 270 prevents the shift fork 260 from further moving in the second direction 264. Therefore, in order to place the vehicle 200 in the park state, the pin 270 can be actuated while the solenoids 252, 254 are energized as described above. When the solenoids 252, 254 are de-energized and the pin 270 is inserted into the slot 268, the movement of the shift fork 260 in the second direction 264 is prevented, thereby maintaining the vehicle 200 in the gear state. When this locking mechanism is engaged on the planetary gear set 240 (eg, both 242 and 244 are engaged), the IWM 206 enters the park state. Although the above description uses the pin 270 to lock the shift fork 260 in place, the principles of the present disclosure may also be implemented with other locking mechanisms.

[0045] Figure 3 Steps of an example method 300 for diagnosing a parking function state of a vehicle and the parking function state of each in-wheel motor of an electric vehicle according to the present disclosure are depicted. For example, the method 300 is performed by the motor / transmission controller 212, the vehicle controller 214 and / or other control circuits, for example, individually or collectively. According to an example aspect of the method 300 and corresponding algorithm, after ignition of a stationary electric vehicle, the algorithm diagnoses the health state of the parking function at the vehicle level and at each corner. The results from each corner (i.e., in-wheel motor) are ultimately merged to determine whether normal operation can continue or whether the electric vehicle should be placed in a HARD or SOFT safety state. When an error is detected in the system that interferes with the parking function (e.g., preventing all corners from maintaining a parking state), a HARD safety state will be entered. The HARD safety state can generally only be cleared by a certified repair organization. When an error is detected that can be mitigated to the point where the vehicle can operate at least partially functionally (e.g., at least one IWM has an operable parking function), a SOFT safety state is entered. This may mean that the vehicle is operating at a reduced performance level, as such a condition indicates that at least one IWM 206 has only partial transmission functionality. The vehicle may require repair to resolve this issue. Although described above with respect to a vehicle having four (i.e., one at each corner / wheel) in-wheel motors configured to enter a parked state, Figure 3 The principle can be applied to vehicles with fewer (eg, only two) in-wheel motors.

[0046] The method 300 may include first checking whether the previous ignition cycle detected a condition where the HARD safety state of an IWM had not been cleared. The operating state of each IWM during the previous drive cycle, including but not limited to, the operator executing a park command, may be used to access the ability of each IWM to implement the park function and thereby implement the necessity of the HARD safety state. Assuming a HARD safety state does not exist, the supervisory level software may query each corner (i.e., IWM) to understand its ability to lock the corner in the park state.

[0047] Upon receiving the request, each in-wheel motor confirms that its respective locking mechanism is functioning properly. Thus, the method confirms that the parking function and locking mechanism of each IWM are functioning properly. It should be noted that in this embodiment, as previously explained, when a vehicle is placed in the park state, both S1 and S2 are energized simultaneously, resulting in the engagement of the LOW and HIGH gears, which lock the planetary gear set to create the park state. Although the present subject embodiment is discussed in relation to multiple locking mechanisms, the method may also be implemented with a single locking mechanism that locks multiple solenoids without departing from the scope of the present subject disclosure. Since the vehicle cannot remain powered, a solenoid "locking" mechanism may be activated to hold the gears in place without maintaining a powered state. Depending on the implementation, there may be a "lock" for each solenoid, or a common lock may be shared. In order to confirm that the parking function is effective in the non-powered state, not only must the solenoid lock be engaged, but the position sensor must confirm that the LOW and HIGH gears are in an engaged state. If the solenoid locking mechanism is engaged and both the LOW and HIGH gears are also in the engaged state, then the parking function is considered to be operational. If any of these elements are not true, it can be assumed that the corner has exited the parking state without power.

[0048] In an example embodiment, at 304, the method 300 first confirms that all corners (i.e., multiple in-wheel motors) are in a parked state before performing diagnostics. At 312, the method 300 confirms whether a selected corner maintains the parked state when not powered (i.e., when the solenoid is not powered, such as when the vehicle is not powered). For example, when the solenoid is de-energized and the locking mechanism (e.g., the pin 270) is actuated, the method 300 can monitor various sensor measurements and / or perform various functions. As an example, the method 300 receives measurement signals from a position sensor, a pressure sensor, etc. to verify whether the LOW and HIGH gears are engaged. For example, a position sensor associated with the respective gears can output a signal greater than or equal to a threshold when the gear is engaged, and output a signal less than the threshold when the gear is not engaged.

[0049] At 316, the method 300 confirms whether the selected corner maintains the park state when powered (i.e., when the solenoid is energized). The method 300 can confirm that the corner is in the park state based on the measurement signals as described above. In one embodiment, the solenoid locking mechanism does not need to be disengaged to test whether the solenoid control (252 / 254 and 248 combined) of the planetary gear set 240 supports the park function when the solenoid is powered. In one example, the method 300 can perform a motor rocking ("ROCKMOTOR") function to determine whether the corner is likely to move when in the park state. The ROCKMOTOR function can correspond to a command to move the gear set forward and backward using a predefined force. For a planetary gear set, when the park function is operable, a known, localized small movement is expected given the tolerances of the gear set. Sensors (e.g., wheel and motor position sensors) are used to detect gear movement. If the LOW and HIGH gears are engaged, the gear movement will be minimal (e.g., below a threshold) and fall within an expected range of movement. If the gear movement is within the expected range, the parking function is considered to be operational. If the gear movement is not within the expected range, it can be assumed that the solenoid locking mechanism is faulty.

[0050] At 320, the method 300 generates a parking diagnostic for the selected corner. For example, the parking diagnostic may include data indicating whether the corner maintains the park state when powered and not powered, as described in steps 312 and 316 above. For example, the data may include two or more data bits. In one example, the data includes two bits having any one of states 00, 01, 10, and 11, where 0 indicates that the park state is not maintained and 1 indicates that the park state is maintained (e.g., 00 indicates that the park state is not maintained when powered or not powered, 01 indicates that the park state is maintained when powered, but not when not powered, etc.).

[0051] At 324, the method 300 determines if all corners have been tested / diagnosed. If true, the method 300 continues to 328. If false, the method 300 continues to 312 to continue diagnosing other corners. In one embodiment, if after repeated attempts to perform 324, it has not been confirmed that all corners have been tested, the method 300 may force a HARD or a SOFT safety state based only on the information provided by the wheel end that has reported its functional status.

[0052] At 328, the method 300 determines if all corners are confirmed to maintain the park state both when powered and unpowered. If true, the method 300 continues to 332. If false, the method 300 continues to 336. At 332, the method 300 enables normal operation. In other words, since all corners of the vehicle maintain the park state both when powered and unpowered, the method 300 determines that there is no parking fault and therefore does not limit the operation of the vehicle.

[0053] At 336, the method 300 determines whether at least one corner of the vehicle is confirmed to remain in the park state when powered and unpowered. If true, the method 300 continues to 340. If false, the method 300 continues to 344. At 340, the method 300 enables a SOFT safety state operation. For example, in the SOFT safety state, at least one in-wheel motor maintains the park function, and therefore the vehicle can be operated with limited functionality. Limited functionality is defined as, but not limited to, being able to enter the park gear state and having at least one IWM capable of providing propulsion in at least one drive gear state.

[0054] At 344, the method 300 enters the HARD safety state operation as described above. In other words, vehicle operation may be prevented because none of the in-wheel motors are able to perform the parking function as described above. In one embodiment, the HARD safety state may drive other operations (e.g., operator warning notification, OEM warning notification, activation of hazard lights, etc.).

[0055] As highlighted by the differences in soft safety / hard safety states described above, the in-wheel motor electric vehicle (EV) architecture can be designed with redundant functionality to maintain operation for the operator even when there may be multiple faults in the vehicle parking function. This functionality can be applied to any drive configuration as long as the configuration includes at least two IWMs with implicit planetary gear sets and related control mechanisms. In addition, since the function is implemented through the mechanical structure of the transmission, no additional mechanical elements are required to meet FMVSS114 requirements (e.g., parking pawls, parking gears, etc.), which can save costs and have quality advantages compared to traditional solutions. In addition, the given method can be utilized to support automatic calibration adjustments throughout the life cycle of the application. Finally, this same method can be used for further functional safety aspects as it can identify potential problems with the transmission before the driver initiates the drive function.

[0056] The above description is illustrative only and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent after studying the drawings, the specification and the appended claims. It should be understood that one or more steps in the method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more of these features described for any embodiment of the present disclosure can be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if such a combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the arrangement of one or more embodiments to each other is still within the scope of the present disclosure.

[0057] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless explicitly described as "directly," when the relationship between a first and a second element is described in the above disclosure, the relationship can be a direct relationship, in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship, in which there are one or more intervening elements (either spatially or functionally) between the first and second elements. As used herein, the phrases "at least one of A, B, and C" and "at least one of A, B, or C" should be interpreted to mean a logical (A or B or C) using a non-exclusive logical "or", and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0058] The terms "a", "an", "the", and "said" herein, in connection with any type of processing component configured to perform various functions, may refer to one processing component configured to perform each function, or to multiple processing components that are collectively configured to perform each of the various functions. By way of example, "a processor" configured to perform actions A, B, and C may refer to one or more processors configured to perform actions A, B, and C. In addition, "a processor" configured to perform actions A, B, and C may also refer to a first processor configured to perform actions A and B, and a second processor configured to perform action C. In addition, "a processor" configured to perform actions A, B, and C may also refer to a first processor configured to perform action A, a second processor configured to perform action B, and a third processor configured to perform action C.

[0059] In addition, in the methods described herein, one or more steps depend on whether one or more conditions are satisfied, and it should be understood that the method can be repeated multiple times so that during the repetition process, all conditions on which the method steps depend are satisfied in different repetitions of the method. For example, if the method requires the first step to be performed when the condition is satisfied and the second step to be performed when the condition is not satisfied, then the ordinary technician will understand that the required steps will be repeated until the conditions are both satisfied and not satisfied, in no particular order. Therefore, one or more steps in the method depend on whether one or more conditions are satisfied, and can be rewritten as a method that is repeated until each condition described in the method is satisfied. However, this is not required by the system or computer-readable medium claim, wherein the system or computer-readable medium contains instructions for performing possible operations based on the satisfaction of the corresponding one or more conditions, so that it can be determined whether the contingency has been satisfied without explicitly repeating the steps of the method until all conditions on which the method steps depend are satisfied. It should also be understood by ordinary technicians in the art that, similar to the method with contingency steps, the system or computer-readable storage medium can repeat the method steps as many times as needed to ensure that all possible steps have been executed.

Claims

1. A method for diagnosing a parking function in a vehicle, the vehicle comprising a plurality of in-wheel motors, each in-wheel motor comprising first and second planetary gear sets, wherein the method comprises, on a computing device: selectively engaging each of the first and second planetary gear sets of each of the plurality of in-wheel motors to place each of the plurality of in-wheel motors in a park condition; engaging a respective locking mechanism of each of the plurality of in-wheel motors; determining whether a corresponding one of the plurality of in-wheel motors maintains the park state when each of the first and second planetary gear sets is engaged and the respective locking mechanism is engaged; as well as The vehicle is operated in a selected one of a plurality of operating modes, the selected operating mode being based on the determination whether a corresponding one of the plurality of in-wheel motors maintains the parked state.

2. The method according to claim 1, characterized in that: The method further comprises: operating the vehicle in a first operating mode in response to determining that each of the plurality of in-wheel motors maintains the park state; operating the vehicle in a second operating mode in response to determining that at least one, but not all, of the plurality of in-wheel motors maintains the park state; as well as The vehicle is operated in a third operating mode in response to determining that none of the plurality of in-wheel motors is maintaining the park state.

3. The method according to claim 1, characterized in that: Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes de-energizing at least one solenoid configured to, when energized, engage the first and second planetary gear sets with a clutch assembly.

4. The method according to claim 3, characterized in that: Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes de-energizing two solenoids that are respectively configured to, when energized, engage the first and second planetary gear sets with the clutch assembly.

5. The method according to claim 4, characterized in that: The first and second planetary gear sets correspond to first and second driving gears, respectively.

6. The method according to claim 1, characterized in that: The vehicle includes two of the plurality of in-wheel motors.

7. The method according to claim 1, characterized in that: The vehicle includes two or more of the plurality of in-wheel motors.

8. The method according to claim 1, characterized in that: The respective locking mechanisms each include a pin configured to selectively engage a shift fork to prevent movement of the shift fork.

9. The method according to claim 1, characterized in that: The respective ones include a single pin configured to selectively engage one or more shift forks to prevent movement of the one or more shift forks.

10. A computing device, characterized in that: The computing device is configured to execute instructions stored in the memory that, when executed, cause the computing device to perform a plurality of steps for diagnosing a parking function in a vehicle, the vehicle comprising a plurality of in-wheel motors, each of the plurality of in-wheel motors comprising first and second planetary gear sets, the plurality of steps comprising: selectively engaging each of the first and second planetary gear sets of each of the plurality of in-wheel motors to place each of the plurality of in-wheel motors in a park condition; engaging a respective locking mechanism of each of the plurality of in-wheel motors; determining whether a corresponding one of the plurality of in-wheel motors maintains the park state when each of the first and second planetary gear sets is engaged and the respective locking mechanism is engaged; and The vehicle is operated in a selected one of a plurality of operating modes, the selected operating mode being based on the determination whether a corresponding one of the plurality of in-wheel motors maintains the parked state.

11. The computing device of claim 10, wherein: The multiple steps also include: operating the vehicle in a first operating mode in response to determining that each of the plurality of in-wheel motors maintains the park state; operating the vehicle in a second operating mode in response to determining that at least one, but not all, of the plurality of in-wheel motors maintains the park state; as well as The vehicle is operated in a third operating mode in response to determining that none of the plurality of in-wheel motors is maintaining the park state.

12. The computing device of claim 10, wherein: Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes de-energizing at least one engagement mechanism configured to, when energized, cause the first and second planetary gear sets to engage a clutch assembly.

13. The computing device of claim 12, wherein: Determining whether the corresponding one of the plurality of in-wheel motors maintains the park state includes de-energizing two engagement mechanisms that are respectively configured to, when energized, cause the first and second planetary gear sets to engage the clutch assembly.

14. The computing device of claim 13, wherein: The first and second planetary gear sets correspond to first and second driving gears, respectively.

15. The computing device of claim 10, wherein: The vehicle includes two of the plurality of in-wheel motors.

16. The computing device of claim 10, wherein: The vehicle includes two or more of the plurality of in-wheel motors.

17. The computing device of claim 10, wherein: The respective locking mechanisms each include a pin configured to selectively engage a shift fork to prevent movement of the shift fork.

18. The computing device of claim 10, wherein: The steps also include updating calibration data located in memory using data from a plurality of sensors and historical vehicle operating data to dynamically adjust thresholds used to determine whether the first and second planetary gear sets are engaged or disengaged during a useful life of the vehicle.

19. The computing device of claim 18, wherein: The steps further include using the updated calibration data for vehicle propulsion operation and for confirming an operating condition of the parking state.

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