Available energy optimization for electric vehicles

Abstract

The invention provides available energy optimization of an electric vehicle. The available energy of electric vertical takeoff and landing (eVTOL) or other electric vehicles is optimized. The optimization may include charging a low voltage (LV) energy source to meet the energy requirements of the LV system and the load on the vehicle prior to performing a landing operation to optimize the available energy of the vehicle by enabling the landing operation to occur independently of a high voltage (HV) energy source that must concurrently power the LV system.

Description

Technical Field

[0001] The present disclosure relates to optimizing the available energy of an electric vehicle, such as but not necessarily limited to optimizing the available energy obtainable from a high voltage (HV) energy source of an electric vertical takeoff and landing (eVTOL) vehicle. Background Art

[0002] A wide range of electric vehicles may require a relatively large amount of electrical energy to power a propulsion system, and such electric vehicles typically operate in a manner where the associated current demand may fluctuate depending on the activity being performed. For example, in the case of an eVTOL vehicle, during takeoff or landing operations, the current demand may increase significantly or approach maximum levels due to the concomitant demand for the flight propulsion system to consume a proportional amount of electrical energy from the electrical energy storage system. Due to the effects of slower diffusion, diffusion congestion, and / or other effects resulting from current demand, the electrical energy storage system may be vulnerable to performance fluctuations. Performance fluctuations can be reflected by the amount by which the available energy of the electrical energy storage system deviates from its thermal dynamic energy capacity. In the case of an eVTOL vehicle or other electric vehicle, where range, speed, duration, and other performance-related parameters and capabilities may depend on having a sufficient electrical energy supply to support relatively high current demand activities, it may be beneficial to optimize the available energy so that the maximum amount of electrical energy and performance can be achieved when needed. Summary of the Invention

[0003] A non-limiting aspect of the present disclosure relates to optimizing the available energy of an electrical energy storage system. The optimization may include predicting the expected demand for relatively high current activity and attempting to improve at least a portion of the predicted demand prior to the relatively high current activity, such as by charging a low voltage (LV) energy source to meet the predicted demand for the LV system prior to the need for a high voltage (HV) energy source to support the relatively high current activity. In the case of an electric vertical takeoff and landing (eVTOL) vehicle, the optimization may include predicting the LV energy required by the LV system during a landing operation and charging the LV energy source prior to the landing operation to meet the predicted LV energy demand such that the landing operation can occur independently of the HV energy source that must concurrently power the LV system. The energy obtainable from the LV energy source can also be used to provide energy during the landing operation (or other high current activity) to assist the HV energy source, as the LV energy source can be used in this manner as a source for providing a large current over a short period of time, such as an ultra-high capacity.

[0004] One non - limiting aspect of the present disclosure relates to a method for optimizing the available energy of a high - voltage (HV) battery, the high - voltage (HV) battery being included on an electric vertical take - off and landing (eVTOL) vehicle to power a flight propulsion system. The method may include: performing a low - voltage (LV) energy prediction after the eVTOL vehicle completes a take - off operation to estimate the expected LV energy consumption that the LV system on the eVTOL vehicle is expected to consume during a landing operation; determining whether the LV energy available from the LV battery on the eVTOL vehicle meets an LV landing threshold, the LV landing threshold indicating that the LV battery has LV energy suitable for supplying all of the expected LV energy consumption; in response to the LV energy not being able to supply all of the expected LV energy consumption, implementing an assist mode before the start of the landing operation, optionally, the assist mode includes using the HV battery to facilitate charging the LV battery before the start of the landing operation; and in response to the LV energy being able to supply all of the expected LV energy consumption, implementing a non - assist mode before the start of the landing operation, optionally, the non - assist mode includes using the LV energy available from the LV battery to power the LV system independently of the HV battery, so as to thereby optimize the available energy of the HV battery by enabling the landing operation to occur independently of the HV battery that must concurrently power the LV system.

[0005] The method may include implementing the assist mode to include using the HV battery to charge the LV battery to a charge level sufficient to meet the LV landing threshold.

[0006] The method may include implementing the assist mode to include using the HV battery to power the LV system while concurrently charging the LV battery.

[0007] The method may include performing an HV energy prediction after the eVTOL vehicle completes a take - off operation, optionally, the HV energy prediction estimates the expected HV energy consumption that the flight propulsion system is expected to consume during a landing operation.

[0008] The method may include determining whether the HV energy available from the HV battery meets an HV landing threshold, the HV landing threshold indicating that the HV battery has HV energy suitable for supplying all of the expected HV energy consumption.

[0009] The method may include: implementing the assist mode to include charging the LV battery to a first charge level sufficient to meet the LV landing threshold in response to the HV energy being able to supply all of the expected HV energy consumption; and implementing the assist mode to include charging the LV battery to a second charge level insufficient to meet the LV landing threshold in response to the HV energy not being able to supply all of the expected HV energy consumption.

[0010] The method may include selecting the second charge level to be proportional to the difference between the HV energy and the HV landing threshold.

[0011] The method may include implementing a preheating mode before implementing an assisted mode and a non-assisted mode. Optionally, the preheating mode uses HV energy provided from the HV battery to power the LV system, so as to optimize the available energy by heating the HV battery faster than in the non-preheated mode.

[0012] The method may include: The non-preheating mode includes using LV energy provided from the LV battery to power the LV system independently of the HV battery that must concurrently power the LV system.

[0013] The method may include restricting the implementation of the preheating mode to the start portion of the cruise operation. Optionally, the start portion corresponds to a predetermined time period that occurs after the eVTOL vehicle reaches the cruise altitude after takeoff operation.

[0014] The method may include selecting the predetermined time period based on the expected length of the flight.

[0015] The method may include selecting a predetermined time period proportional to the expected length of the flight.

[0016] The method may include: The HV battery includes a plurality of battery cells having a lithium-ion configuration, characterized in that the battery cells experience slower diffusion and slower reduction of available energy when the current demand is large.

[0017] A non-limiting aspect of the present disclosure relates to a method for optimizing the available energy of a high-voltage (HV) energy source, the high-voltage (HV) energy source being included on an electric vehicle to power a propulsion system. The method may include determining whether the LV energy obtainable from a low-voltage (LV) energy source on the electric vehicle meets an LV landing threshold, the LV landing threshold indicating that the LV energy source has LV energy suitable for supplying all expected LV energy consumption for a landing operation. The method may include implementing an assisted mode before the start of the landing operation in response to the LV energy not being able to supply all expected LV energy consumption. Optionally, the assisted mode includes using HV energy provided from the HV energy source to charge the LV energy source until the LV energy source is able to supply all expected LV energy consumption, so as to optimize the available energy of the HV energy source by enabling the landing operation to occur independently of the HV energy source that must concurrently power the LV system.

[0018] The method may include determining whether the HV energy obtainable from the HV energy source meets an HV landing threshold, the HV landing threshold indicating that the HV energy source has HV energy suitable for supplying all expected HV energy consumption for a landing operation.

[0019] The method may include suspending the assisted mode in response to the HV energy not being able to supply all expected HV energy consumption to prevent further use of the HV energy source in charging the LV energy source.

[0020] The method may include: an HV energy source including a plurality of battery cells having a lithium-ion configuration, characterized in that the battery cells undergo diffusion fluctuations proportional to the current demand thereon.

[0021] The method may include determining an expected HV energy consumption based at least in part on predicting an expected amount of diffusion occurring at the terminals of the HV energy source during a landing operation.

[0022] A non-limiting aspect of the present disclosure relates to a system for optimizing available energy of an electric vehicle. The electric vehicle may include an electric propulsion system configured to convert high voltage (HV) energy into mechanical energy suitable for propelling the electric vehicle, and an LV bus configured to distribute LV energy to one or more low voltage (LV) systems on the electric vehicle. The system may include: a rechargeable energy storage system (RESS) configured to supply HV energy to the electric propulsion system and LV energy to the LV bus, the RESS including a plurality of energy battery cells configured to store and supply electrical energy; and an available energy controller. The available energy controller may be configured to: determine whether the LV energy available from an LV energy source connected to the low voltage (LV) bus meets an LV landing threshold, the LV landing threshold indicating that the LV energy source has LV energy suitable for supplying all of the expected LV energy consumption for a landing operation; in response to the LV energy not being able to supply all of the expected LV energy consumption, implement an assist mode before the start of the landing operation, optionally, the assist mode includes charging the LV energy source using HV energy provided from the RESS until the LV energy source is able to supply all of the expected LV energy consumption; and in response to the LV energy being able to supply all of the expected LV energy consumption, implement a non-assist mode before the start of the landing operation, optionally, the non-assist mode includes relying on the LV energy source to power the LV system independently of the RESS.

[0023] The available energy controller may be configured to implement a warm-up mode before implementing the assist mode and the non-assist mode, optionally, the warm-up mode uses HV energy provided from the RESS to power the LV system, thereby optimizing the available energy by heating the HV energy source of the RESS faster than the LV system is powered independently of the HV energy source.

[0024] The HV energy source may include a plurality of battery cells having a lithium-ion configuration.

[0025] The following solutions are provided:

[0026] 1. A method for optimizing available energy of a high voltage (HV) battery, the high voltage (HV) battery being included on an electric vertical takeoff and landing (eVTOL) vehicle to power a flight propulsion system, the method including:

[0027] Perform low-voltage (LV) energy prediction after the eVTOL vehicle completes takeoff operation, where the LV energy prediction estimates the expected LV energy consumption that the LV system on the eVTOL vehicle is expected to consume during landing operation;

[0028] Determine whether the LV energy available from the LV battery on the eVTOL vehicle meets the LV landing threshold, where the LV landing threshold indicates that the LV battery has LV energy suitable for supplying all the expected LV energy consumption;

[0029] In response to the LV energy not being able to supply all the expected LV energy consumption, implement an assist mode before the start of the landing operation, where the assist mode includes using the HV battery to facilitate charging the LV battery before the start of the landing operation; and

[0030] In response to the LV energy being able to supply all the expected LV energy consumption, implement a no-assist mode before the start of the landing operation, where the no-assist mode includes using the LV energy available from the LV battery to power the LV system independently of the HV battery, thereby optimizing the available energy of the HV battery by enabling the landing operation to occur independently of the HV battery that must concurrently power the LV system.

[0031] 2. The method according to claim 1, further comprising:

[0032] Implement the assist mode to include using the HV battery to charge the LV battery to a charge level sufficient to meet the LV landing threshold.

[0033] 3. The method according to claim 2, further comprising:

[0034] Implement the assist mode to include using the HV battery to power the LV system while concurrently charging the LV battery.

[0035] 4. The method according to claim 1, further comprising:

[0036] Perform high-voltage (HV) energy prediction after the eVTOL vehicle completes takeoff operation, where the HV energy prediction estimates the expected HV energy consumption that the flight propulsion system is expected to consume during landing operation.

[0037] 5. The method according to claim 4, further comprising:

[0038] Determine whether the HV energy available from the HV battery meets the HV landing threshold, where the HV landing threshold indicates that the HV battery has HV energy suitable for supplying all the expected HV energy consumption.

[0039] 6. The method according to claim 5, further comprising:

[0040] Implement an assist mode to include charging the LV battery to a first charge level sufficient to meet the LV landing threshold in response to the HV energy being able to supply all of the expected HV energy consumption; and

[0041] Implement an assist mode to include charging the LV battery to a second charge level insufficient to meet the LV landing threshold in response to the HV energy not being able to supply all of the expected HV energy consumption.

[0042] 7. The method according to claim 6, further comprising:

[0043] Select the second charge level to be proportional to the difference between the HV energy and the HV landing threshold.

[0044] 8. The method according to claim 1, further comprising:

[0045] Implement a preheat mode before implementing the assist mode and the non - assist mode, the preheat mode using HV energy provided from the HV battery to power the LV system, thereby optimizing the available energy by heating the HV battery faster than in the non - preheat mode.

[0046] 9. The method according to claim 8, further comprising:

[0047] The non - preheat mode includes using LV energy provided from the LV battery to power the LV system independently of the HV battery that must concurrently power the LV system.

[0048] 10. The method according to claim 8, further comprising:

[0049] Limit the implementation of the preheat mode to the start portion of the cruise operation, the start portion corresponding to a predetermined time period that occurs after the eVTOL vehicle reaches the cruise altitude after a takeoff operation.

[0050] 11. The method according to claim 10, further comprising:

[0051] Select the predetermined time period based on the expected length of the flight.

[0052] 12. The method according to claim 10, further comprising:

[0053] Select a predetermined time period proportional to the expected length of the flight.

[0054] 13. The method according to claim 1, further comprising:

[0055] The HV battery includes a plurality of battery cells having a lithium - ion configuration, characterized in that the battery cells experience slower diffusion and slower reduction of available energy when the current demand is high.

[0056] 14. A method for optimizing the available energy of a high voltage (HV) energy source, the high voltage (HV) energy source being included on an electric vehicle to power a propulsion system, the method comprising:

[0057] Determining whether the LV energy available from a low voltage (LV) energy source on the electric vehicle meets an LV landing threshold, the LV landing threshold indicating that the LV energy source has LV energy suitable for supplying all expected LV energy consumption for a landing operation; and

[0058] In response to the LV energy not being able to supply all expected LV energy consumption, implementing an auxiliary mode before the start of a landing operation, the auxiliary mode including charging the LV energy source using HV energy provided from the HV energy source until the LV energy source is able to supply all expected LV energy consumption, thereby optimizing the available energy of the HV energy source by enabling the landing operation to occur independently of the HV energy source that must concurrently power the LV system.

[0059] 15. The method according to claim 14, further comprising:

[0060] Determining whether the HV energy available from the HV energy source meets an HV landing threshold, the HV landing threshold indicating that the HV energy source has HV energy suitable for supplying all expected HV energy consumption for a landing operation.

[0061] 16. The method according to claim 15, further comprising:

[0062] In response to the HV energy not being able to supply all expected HV energy consumption, pausing the auxiliary mode to prevent further use of the HV energy source in charging the LV energy source.

[0063] 17. The method according to claim 16, further comprising:

[0064] The HV energy source includes a plurality of battery cells having a lithium-ion configuration, characterized in that the battery cells experience diffusion fluctuations proportional to the current demand thereon.

[0065] 18. The method according to claim 17, further comprising:

[0066] Determining the expected HV energy consumption based at least in part on the expected amount of diffusion predicted to occur at the terminals of the HV energy source during a landing operation.

[0067] 19. A system for optimizing the available energy of an electric vehicle, the electric vehicle including an electric propulsion system configured to convert high voltage (HV) energy into mechanical energy suitable for propelling the electric vehicle, and an LV bus configured to distribute LV energy to one or more low voltage (LV) systems on the electric vehicle, the system comprising:

[0068] A rechargeable energy storage system (RESS) configured to supply HV energy to an electric propulsion system and LV energy to an LV bus, the RESS including a plurality of energy battery units configured to store and supply electrical energy; and

[0069] An available energy controller configured to:

[0070] Determine whether the LV energy available from an LV energy source connected to a low voltage (LV) bus meets an LV landing threshold, the LV landing threshold indicating that the LV energy source has LV energy suitable for supplying all expected LV energy consumption for a landing operation;

[0071] In response to the LV energy not being able to supply all expected LV energy consumption, implement an assist mode before the start of a landing operation, the assist mode including charging the LV energy source using HV energy provided from the RESS until the LV energy source is able to supply all expected LV energy consumption; and

[0072] In response to the LV energy being able to supply all expected LV energy consumption, implement a non - assist mode before the start of a landing operation, the non - assist mode including relying on the LV energy source to power the LV system independently of the RESS.

[0073] 20. The system according to claim 19, wherein:

[0074] The available energy controller is configured to implement a pre - heat mode before implementing the assist mode and the non - assist mode, the pre - heat mode using HV energy provided from the RESS to power the LV system, thereby optimizing available energy by heating the HV energy source of the RESS faster than the LV system is powered independently of the HV energy source; and

[0075] The HV energy source includes a plurality of battery cells having a lithium - ion configuration.

[0076] These features and advantages of the present teachings, as well as other features and advantages, will be readily apparent from the following detailed description of the modes of practicing the teachings when taken in conjunction with the drawings. It should be understood that although the following drawings and embodiments may be described separately, their individual features may be combined into additional embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The drawings, which can be incorporated into the specification and form a part thereof, illustrate implementations of the present disclosure and, together with the description, are used to explain the principles of the present disclosure.

[0078] Figure 1 A schematic view of a vehicle configured to optimize available energy in accordance with a non - limiting aspect of the present disclosure is shown.

[0079] Figure 2A flowchart of a method for optimizing available energy according to a non - limiting aspect of the present disclosure is shown. Detailed implementation

[0080] As needed, detailed embodiments of the present disclosure may be disclosed herein; however, it is understood that the disclosed embodiments may merely be examples of the present disclosure, and the present disclosure may be embodied in various and alternative forms. The drawings may not necessarily be to scale; some features may be enlarged or minimized to show details of particular components. Thus, the specific structural and functional details disclosed herein need not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to employ the present disclosure in different ways.

[0081] Figure 1 A schematic view of a vehicle 12 configured to optimize available energy according to a non - limiting aspect of the present disclosure is shown. The vehicle 12 is described primarily with respect to a type of electric vertical take - off and landing (eVTOL) vehicle 12 configured to be capable of flight. The vehicle 12 may include a propulsion system 14 configured to convert electrical energy into mechanical energy, which is operable for the purpose of generating thrust, lift, or other forces sufficient to perform vertical take - off and landing operations. Although not shown separately, the propulsion system 14 may include an electric motor operable with a drive system or other mechanical system that is operable to generate thrust sufficient to lift the vehicle 12 off the ground as part of a take - off operation, propel the vehicle 12 in the air as part of a cruise operation, and thereafter land the vehicle 12 on the ground as part of a landing operation. The vehicle 12, and in particular the propulsion system 14, may be configured to facilitate flight typically associated with drones, helicopters, airplanes, and / or other machines capable of flight in the air. For exemplary purposes, the vehicle 12 is presented as representative of a broad class of electric vehicles, where during certain activities, such as take - off or landing operations, the current demand of the propulsion system 14 may increase significantly or approach maximum levels due to the concomitant need for the propulsion system 14 to consume a proportional amount of electrical energy accordingly. This is done for non - limiting purposes, as the present disclosure fully contemplates its use and application with other types of vehicles that may benefit from optimizing available energy in the manner described herein, including electric trucks or equipment that may utilize the propulsion system 14 for ground or non - aerial movement or work.

[0082] Vehicle 12 may include a rechargeable energy storage system (RESS) 16 configured to store and supply electrical energy. RESS 16 may include various components configured to store and supply electrical energy, which in the exemplary illustration may include a first energy source 20 and a second energy source 22. The first energy source may be considered an operable high voltage (HV) energy source for storing and supplying HV energy, and the second energy source may be considered a separate low voltage (LV) energy source operable for storing and supplying LV energy. The HV and LV energy sources 20, 22 may each include one or more battery cells (not shown), optionally arranged in one or more modules (not shown). The HV energy source 20 may include more and / or higher battery cells and / or modules than the LV energy source 22, and optionally, its battery cells / modules are connected in a specific manner such that the HV energy source 20 can store and supply electrical energy at a relatively higher level than the LV energy source 22. The battery cells may be composed of a wide variety of components operable for storing and supplying electrical power. For example, the battery cells may include lithium-ion materials or other material chemistries suitable for storing and supplying electrical power, and optionally, some battery cells have a mixed or different chemistry from some other battery cells. However, the use of battery cells is presented for non-limiting purposes, as the present disclosure fully contemplates that the battery cells are other types of energy battery cells capable of storing and / or supplying electrical power, such as but not necessarily limited to energy battery cells partially or wholly composed of capacitors, supercapacitors, fuel cell units, and / or other types of energy components.

[0083] RESS16 may optionally include a converter 26 connected between the HV and LV energy sources 20, 22, e.g., via an HV or main bus 28 connected to the HV energy source 20 and the propulsion system 14 and an LV or auxiliary bus 30 connected to the LV energy source 22 and one or more LV systems 32. The LV system 32 may include a plurality of different systems and is shown for non-limiting purposes as including an auxiliary power unit 34, which may be operable to power accessories, heating, ventilation, and air conditioning (HVAC), and / or other auxiliary systems 36. The converter 26 may be configured to convert electrical energy for distribution between the HV and / or LV buses 28, 30. For example, the converter 26 may be a direct current (DC) to DC (DC-DC) converter 26 or other suitable converter 26, which may be operable to convert HV energy obtainable from the HV energy source 20 for use on the LV bus 30 and / or convert LV energy obtainable from the LV energy source 22 for use on the HV bus 28. For non-limiting purposes, the converter 26 is presented as representative of various systems that may be used to facilitate managing the distribution of electrical energy between multiple energy sources on the vehicle 12. The vehicle 12 may include a controller 40 to facilitate monitoring, controlling, measuring, and otherwise directing operations, performance, etc. on the vehicle 12, which may include performing measurements, taking readings, or otherwise collecting data to facilitate operations. The controller 40 may include additional controllers (not shown) that may optionally perform associated operations in accordance with corresponding non-transitory instructions executed by one or more processors stored in one or more computer-readable storage media.

[0084] Due to the effects of slower diffusion, diffusion congestion, and / or other effects resulting from the current demands on the HV and LV energy sources 20, 22 during operation of the vehicle 12, the RESS16 may be vulnerable to performance fluctuations. For example, diffusion may involve a reduction in the surface density of the terminals (e.g., the anode lithium surface) of the HV energy source 20, such that the maximum possible terminal voltage there is correspondingly reduced, thereby limiting the available power. Due to the relatively greater current demand of the propulsion system 14 compared to the LV system 32, the resulting performance fluctuations may be relatively more pronounced for the HV energy source 20 than the LV energy source 22. For the sake of simplicity of presentation, the present disclosure is described primarily with respect to optimizing the available energy of the HV energy source 20 in order to maximize its performance and / or limit performance fluctuations, which may be particularly beneficial in improving the performance, flight range, lifespan, efficiency, etc. of the propulsion system 14. Performance fluctuations may be reflected in the amount by which the available energy of the HV energy source 20 at a given point in time deviates from its thermal dynamic energy capacity. The thermal dynamic energy capacity may be a representation of the maximum or theoretical amount of electrical energy obtainable from the HV energy source 20 under ideal or design conditions. In contrast, the available energy may be a representation of the operational amount of electrical energy actually obtainable from the HV energy source 20 given the current operating conditions, environment, etc.

[0085] In the case of an eVTOL vehicle or other electric vehicle, where range, speed, duration, and other performance-related parameters and capabilities can depend on having sufficient electrical energy supply to support activities with relatively high current demands, it can be beneficial to optimize the available energy of the HV energy source 20 such that the maximum amount of electrical energy and performance can be achieved when needed. A non-limiting aspect of the present disclosure relates to the controller 40 being or including an available energy controller 40 operable to optimize the available energy of the HV energy source 20. Related optimizations can include predicting the expected demand for relatively high current activities and attempting to improve at least a portion of the predicted demand prior to the relatively high current activity, such as by charging the LV energy source 22 to meet the predicted demand of the LV system 32 before the HV energy source 20 is required to support a relatively high current activity. For example, in the case of an electric vertical takeoff and landing (eVTOL) vehicle 12, the optimization can include predicting the LV energy required by the LV system 32 during a landing operation and charging the LV energy source 22 prior to the landing operation to meet the predicted LV energy demand such that the landing operation can occur independently of the HV energy source 20 that must concurrently power the LV system 32.

[0086] Figure 2 A flowchart 44 of a method for optimizing available energy in accordance with a non-limiting aspect of the present disclosure is shown. The method is described primarily with respect to optimizing the available energy of the HV energy source 20 within the vehicle 12; however, as will be understood by those skilled in the art, the envisioned optimizations can be beneficial to other types of energy sources, including but not necessarily limited to non-HV energy sources and / or energy sources included within other types of vehicles. The method can be implemented in accordance with various systems, processes, controls, etc., and for non-limiting purposes is described with respect to the controller 40 being or including an available energy controller 40 that can operate in accordance with a corresponding plurality of non-transitory instructions stored on one or more computer-readable storage media by one or more processors associated therewith.

[0087] Box 50 involves the controller 40 implementing a warm-up mode after the vehicle 12 has completed a takeoff operation or otherwise engaged in a suitable operational activity. The warm-up mode may begin after the propulsion system 14 has consumed electrical energy from the HV energy source 20 to lift the vehicle 12 off the ground to begin cruise operation, at which time it may be desirable for the vehicle 12 to perform a flight from one location to another, hover at a particular location, or otherwise engage in aerial operations. The warm-up mode may include using HV energy provided from the HV energy source 20 (i.e., via the converter 26) to power the LV system 32 to optimize the available energy by heating the HV energy source 20 faster than the LV system 32 is powered independently of the HV energy source 20. The warm-up mode may be contrasted with a non-warm-up or standard mode in which the LV system 32 may be powered independently of the HV energy source 20 using LV energy provided from the LV energy source 22, i.e., without the need for the converter 26 to convert HV energy for use on the LV bus. The warm-up mode may optionally be limited to the beginning portion of the cruise operation, which corresponds to a predetermined time period that occurs after the vehicle 12 has reached a cruise altitude or other suitable state after a takeoff operation. The predetermined time period may be based on and / or proportional to the expected length of the flight such that the predetermined time period may be longer when the expected length of the flight is longer and shorter when the expected length of the flight is shorter.

[0088] Box 52 involves the controller 40 performing an LV energy prediction as part of an LV prediction process. For non-limiting purposes, the LV prediction process is shown to occur after the warm-up mode since the warm-up mode may be completely omitted, skipped in the case of a too-short flight, or the warm-up process may occur concurrently with the LV prediction process. A non-limiting aspect of the present disclosure contemplates that the LV prediction process is an iterative or ongoing process in which the controller 40 may repeat the predictions contemplated herein throughout the flight in order to optimize the available energy of the HV energy source 20 prior to the start of a landing operation. The LV prediction process may include estimating the expected LV energy consumption that the LV system 32 may be expected to consume while a landing operation is in progress.

[0089] Box 54 relates to the LV assessment process, where the controller 40 can determine whether the LV energy currently available from the LV energy source 22 is sufficient to meet the LV landing threshold, which indicates that the LV energy source 22 has LV energy suitable for supplying all the expected LV energy consumption. If the LV energy source 22 is operable to meet the demand without using the converter 26 to convert the HV energy provided from the HV energy source 20, the LV energy source 22 can be considered to include sufficient LV energy. The LV landing threshold can be a variable that changes throughout the flight and / or a variable that changes from one type of vehicle 12 to another type of vehicle 12. Thus, the LV landing threshold can increase or decrease during the flight, optionally in response to changes in wind conditions, altitude, humidity, etc. and / or depending on the capabilities of the vehicle 12 and / or the propulsion system 14. The LV landing threshold can optionally relate to operating with less than the minimum amount of LV energy required for each system LV system 32, e.g., the minimum subset required to land the vehicle 12 appropriately or desirably. The LV landing threshold can thus correspond to the minimum amount of LV energy required if the vehicle 12 were to immediately or concurrently start a landing operation at a given point or time during the flight.

[0090] Box 56 relates to implementing an unassisted mode prior to the start of a landing operation in response to the LV energy being able to supply all the expected LV energy consumption. The unassisted mode can include powering the LV system 32 independently of the HV battery using LV energy available from the LV battery. The limitation of using LV energy from the LV energy source 22 during the unassisted mode can correspondingly optimize the available energy of the HV battery by enabling the landing operation to occur independently of the HV battery that must concurrently power the LV system 32. The ability to prevent concurrent use of the HV energy source 20 to power the LV system 32 during the landing operation can reduce the current demand on the HV energy system, such that the amount of dissipation occurring at the terminals of the HV energy source 20 during the landing operation can be reduced compared to a scenario where the HV energy system might be required to concurrently power the LV system 32 during landing. The feasibility of the unassisted mode can be continuously re-evaluated throughout the flight to continuously determine whether a sufficient amount of LV energy is available from the LV energy source 22 to meet the expected LV energy consumption when the vehicle 12 subsequently starts a landing operation.

[0091] Block 58 involves the controller 40 performing HV energy prediction as part of the HV prediction process. For non-limiting purposes, the prediction process is shown to occur after the LV prediction process, as the HV prediction process can be an ongoing process that can occur concurrently with the LV prediction. A non-limiting aspect of the present disclosure contemplates that the HV prediction process is an iterative or ongoing process, where the controller 40 can repeat the predictions contemplated herein throughout the flight to optimize the available energy of the HV energy source 20 prior to the start of the landing operation. The HV prediction process can include estimating the expected HV energy consumption that the HV system may be expected to consume during the execution of the landing operation, i.e., the HV energy that the propulsion system 14 or other HV-related systems may require to facilitate the landing of the vehicle 12. The HV prediction process can include determining whether the HV energy currently available from the HV energy source 20 is sufficient to meet the HV landing threshold, which indicates that the HV energy source 20 has HV energy suitable for supplying all of the expected HV energy consumption. The HV landing threshold can optionally be at least partially based on the expected amount of dissipation predicted to occur at the terminals of the HV energy source 20 during the landing operation. Like the LV threshold, the HV landing threshold can be a variable that varies throughout the flight and / or varies from one type of vehicle 12 to another type of vehicle 12. The HV landing threshold can thus correspond to the minimum amount of HV energy required if the vehicle 12 were to immediately or concurrently start the landing operation at a given point or time during the flight.

[0092] Block 60 involves implementing an auxiliary mode prior to the start of the landing operation in response to the LV energy not being able to supply all of the expected LV energy consumption. The auxiliary mode can include using the HV battery to facilitate charging of the LV battery prior to the start of the landing operation, which can include charging the LV battery to a first charge level sufficient to meet the LV landing threshold in response to the HV energy being able to supply all of the expected HV energy consumption, and charging the LV battery to a second charge level insufficient to meet the LV landing threshold in response to the HV energy not being able to supply all of the expected HV energy consumption. The second charge level can be selected to be proportional to the difference between the HV energy and the HV landing threshold, i.e., the second charge level can be larger when the difference is small and the second charge level can be smaller when the difference is large. In other words, the second charge level can correspond to the maximum amount of the ability of the HV energy source 20 to be able to charge the LV energy source 22 while still maintaining the vehicle 12 within the desired acceptable landing parameters or requirements. The auxiliary mode can optionally include reducing the flight duration or otherwise taking corrective action such that the HV energy source 20 can be used to charge the LV battery as fully as reasonably possible to meet the expected LV energy consumption of the landing operation.

[0093] Block 62 relates to the maintenance process, in which the charging of the LV energy source 22 using the HV energy source 20 can be ongoing throughout the flight, i.e., it can be an ongoing process in which the HV energy source 20 is used to periodically charge the LV energy source 22 during flight. The charging can be iteratively implemented by repeatedly using the HV energy source 20 to charge the LV energy source 22 each time the LV energy source 22 drops below the LV landing threshold, while the HV energy source 20 has sufficient reserve to meet the HV landing threshold. This charging of the LV energy source 22 can optionally be supplemented by a regeneration system (not shown) included on the vehicle 12, which concurrently generates electrical energy sufficient to provide additional energy to power and charge the LV and / or HV energy sources 20, 22. The charging can continue until the LV energy source 22 is fully charged to meet the LV landing threshold, or the HV energy source 20 can no longer maintain charging of the LV energy source 22 while maintaining an acceptable energy reserve for powering the propulsion system 14 required for landing operations, which for illustrative purposes is shown in the block to include a return to the unassisted mode. This ability to charge the LV energy source 22 before the onset of high current demand on the LV energy source 22 can reduce dissipation and thus optimize the available energy, which is attributed to potentially reducing the current demand on the HV energy source 20 during landing and other high current activities by enabling landing and other high current activities to occur independently of the HV energy source 20 that must concurrently power the LV system 32.

[0094] While various embodiments have been described, the description is intended to be exemplary, not restrictive, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments. Any feature of any embodiment can be used in combination with or substituted for any other feature or element in any other embodiment, unless specifically restricted. Thus, the embodiments are not limited except as defined by the appended claims and their equivalents. Additionally, various modifications and variations are possible within the scope of the appended claims. Although several modes for carrying out many aspects of the present teachings have been described in detail, those skilled in the art familiar with the fields involved in these teachings will recognize various alternative aspects for practicing the present teachings within the scope of the appended claims. It is intended that all content included in the above description or shown in the drawings be interpreted as illustrative and exemplary of the entire range of alternative embodiments, which alternative embodiments will be recognized by those of ordinary skill in the art as being implied by, structurally and / or functionally equivalent to, or otherwise made apparent based on, the content included, and not limited to those explicitly depicted and / or described embodiments.

Claims

1. A method for optimizing the available energy of a high voltage (HV) battery, the high voltage (HV) battery being included on an electric vertical takeoff and landing (eVTOL) vehicle to power a flight propulsion system, the method comprising: Performing a low voltage (LV) energy prediction after the eVTOL vehicle completes a takeoff operation, the LV energy prediction estimating an expected LV energy consumption that the LV system on the eVTOL vehicle is expected to consume during a landing operation; Determining whether the LV energy available from the LV battery on the eVTOL vehicle meets an LV landing threshold, the LV landing threshold indicating that the LV battery has LV energy suitable for supplying all of the expected LV energy consumption; In response to the LV energy not being able to supply all of the expected LV energy consumption, implementing an assist mode before the landing operation begins, the assist mode including using the HV battery to facilitate charging the LV battery before the landing operation begins; And In response to the LV energy being able to supply all of the expected LV energy consumption, implementing a non-assist mode before the landing operation begins, the non-assist mode including using the LV energy available from the LV battery to power the LV system independently of the HV battery, thereby optimizing the available energy of the HV battery by enabling the landing operation to occur independently of the HV battery that must concurrently power the LV system.

2. The method according to claim 1, further comprising: Implementing the assist mode to include charging the LV battery to a charge level sufficient to meet the LV landing threshold using the HV battery.

3. The method according to claim 2, further comprising: Implementing the assist mode to include using the HV battery to power the LV system while concurrently charging the LV battery.

4. The method according to claim 1, further comprising: Performing an HV energy prediction after the eVTOL vehicle completes a takeoff operation, the HV energy prediction estimating an expected HV energy consumption that the flight propulsion system is expected to consume during a landing operation.

5. The method according to claim 4, further comprising: Determining whether the HV energy available from the HV battery meets an HV landing threshold, the HV landing threshold indicating that the HV battery has HV energy suitable for supplying all of the expected HV energy consumption.

6. The method according to claim 5, further comprising: Implementing the assist mode to include charging the LV battery to a first charge level sufficient to meet the LV landing threshold in response to the HV energy being able to supply all of the expected HV energy consumption; And Implementing the assist mode to include charging the LV battery to a second charge level insufficient to meet the LV landing threshold in response to the HV energy not being able to supply all of the expected HV energy consumption.

7. The method according to claim 6, further comprising: Selecting the second charge level to be proportional to the difference between the HV energy and the HV landing threshold.

8. The method according to claim 1, further comprising: Implementing a preheat mode before implementing the assist mode and the non-assist mode, the preheat mode using HV energy provided from the HV battery to power the LV system, thereby optimizing the available energy by heating the HV battery faster than in a non-preheat mode.

9. The method according to claim 8, further comprising: The non-preheating mode includes powering the LV system using LV energy provided from the LV battery independently of the HV battery that must concurrently power the LV system.

10. The method according to claim 8, further comprising: Restricting the implementation of the preheating mode to a start portion of a cruise operation, the start portion corresponding to a predetermined time period that occurs after the eVTOL vehicle reaches a cruise altitude after a takeoff operation.

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