A method for estimating coolant flow rate in a vehicle

Abstract

This invention discloses a method for estimating vehicle coolant flow rate. The method includes: acquiring at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss; for each current temperature, previous temperature, and current power loss, determining the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature, and determining the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference, and the current power loss; and determining the current coolant flow rate based on each current dynamic thermal resistance. This method solves the problems of high cost and large workload in vehicle coolant flow rate measurement, provides real-time and accurate estimation of coolant flow rate, eliminates the need for flow sensor installation, is not limited by mechanical installation, has low cost, and is applicable to any situation.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method for estimating onboard coolant flow rate. Background Technology

[0002] With the rapid development and increasing sophistication of new energy vehicle technology, users' demands for the functionality and performance of electric vehicles are also gradually increasing, including vehicle safety and reliability. As one of the core components of an electric vehicle, the motor controller generates a significant amount of heat during operation. Accumulated heat can severely affect the working state and lifespan of the motor drive system, posing a significant challenge to the complex operating conditions of the entire vehicle. Therefore, a reasonable heat dissipation design for the motor drive system is particularly important. Typically, liquid cooling is used to cool the motor drive system, while the temperature and flow rate of the coolant are monitored to understand the real-time operating status of the cooling system. Coolant temperature can be measured using a thermistor placed in the cooling circuit. Coolant flow rate can be measured by installing a flow sensor in the cooling circuit. However, flow sensors are limited by mechanical installation constraints and are costly; therefore, most electric vehicles do not integrate flow monitoring instruments. Existing methods for obtaining flow rate through offline calibration are labor-intensive and have limited applicability. Summary of the Invention

[0003] This invention provides a method for estimating vehicle coolant flow rate to solve the problems of high cost and large workload in measuring vehicle coolant flow rate.

[0004] According to one aspect of the present invention, a method for estimating vehicle coolant flow rate is provided, comprising:

[0005] Obtain at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss;

[0006] For each current temperature, previous temperature, and current power loss, the current temperature difference and previous temperature difference are determined based on the current temperature and previous temperature combined with the initial steady-state temperature, and the current dynamic thermal resistance is determined based on the current temperature difference, previous temperature difference, and current power loss.

[0007] The current coolant flow rate is determined based on the current dynamic thermal resistance described above.

[0008] According to another aspect of the present invention, an on-board coolant flow estimation device is provided, comprising:

[0009] The temperature acquisition module is used to acquire at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss.

[0010] The current thermal resistance determination module is used to determine the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature for each current temperature, the previous temperature and the current power loss, and to determine the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference and the current power loss.

[0011] The current flow rate determination module is used to determine the current coolant flow rate based on the current dynamic thermal resistance.

[0012] According to another aspect of the present invention, a vehicle is provided, the vehicle comprising:

[0013] At least one processor; and

[0014] A memory communicatively connected to the at least one processor; wherein,

[0015] The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the vehicle coolant flow estimation method according to any embodiment of the present invention.

[0016] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the vehicle coolant flow estimation method according to any embodiment of the present invention.

[0017] The technical solution of this invention obtains at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss; for each current temperature, previous temperature, and current power loss, the current temperature difference and the previous temperature difference are determined based on the current temperature and the previous temperature combined with the initial steady-state temperature, and the current dynamic thermal resistance is determined based on the current temperature difference, the previous temperature difference, and the current power loss; the current coolant flow rate is determined based on each current dynamic thermal resistance. This solves the problems of high cost and large workload in vehicle coolant flow rate measurement. By comparing the temperature of the motor controller with the initial steady-state temperature to determine the temperature difference, the current dynamic thermal resistance is calculated based on the temperature difference and the power loss, and then the current coolant flow rate is estimated based on the current dynamic thermal resistance. This allows for real-time and accurate estimation of coolant flow rate, without the need for a flow sensor, without being limited by mechanical installation, with low cost, and applicable to any occasion.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a method for estimating vehicle coolant flow rate according to Embodiment 1 of the present invention;

[0021] Figure 2 This is a flowchart of a vehicle-mounted coolant flow estimation method according to Embodiment 2 of the present invention;

[0022] Figure 3 This is an example diagram of a heat network model provided in Embodiment 2 of the present invention;

[0023] Figure 4 This is a temperature response curve provided according to Embodiment 2 of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of an on-board coolant flow estimation device according to Embodiment 3 of the present invention;

[0025] Figure 6 This is a schematic diagram of the vehicle structure for implementing the vehicle-mounted coolant flow estimation method of this invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "target," "current," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] Example 1

[0029] Figure 1 This is a flowchart illustrating a method for estimating vehicle coolant flow rate according to Embodiment 1 of the present invention. This embodiment is applicable to situations requiring real-time estimation of vehicle coolant flow rate. The method can be executed by an on-board coolant flow rate estimation device, which can be implemented in hardware and / or software and can be configured in the vehicle. Figure 1 As shown, the method includes:

[0030] S101. Obtain at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss.

[0031] In this embodiment, the current temperature can be specifically understood as the temperature collected at the current flow estimation time, and the previous temperature can be specifically understood as the temperature collected at the previous flow estimation time. When collecting temperatures, the number of collected temperatures is related to the motor controller. For example, if the motor controller is a three-phase motor, the number of current temperatures collected is three. The current power loss can be specifically understood as the power loss of the motor controller at the current flow estimation time, for example, the total loss of the IGBT and diode. For example, when the motor controller is a three-phase motor, each current power loss is the total power loss (total loss of the IGBT and diode) of the bridge arm where each phase NTC of the three-phase motor controller is located.

[0032] Specifically, a temperature sensor is deployed on the motor controller to collect temperature data. For example, when the motor controller is a three-phase motor controller, the temperature sensor can be a three-phase NTC temperature sensor, which collects the temperature of each phase. The current power loss can be calculated using information such as current and voltage to determine the current power loss of each phase. When estimating the coolant flow rate, it can be done cyclically by setting a period, or by setting automatic trigger conditions or receiving user triggers. This application preferably uses a cyclical method for flow estimation. The temperature is saved after each data collection, so that the previously collected temperature can be directly retrieved for the next coolant flow rate estimation. If there are multiple current temperatures, they are identified when saving to distinguish between different temperatures.

[0033] S102. For each current temperature, previous temperature, and current power loss, determine the current temperature difference and previous temperature difference based on the current temperature and previous temperature combined with the initial steady-state temperature, and determine the current dynamic thermal resistance based on the current temperature difference, previous temperature difference, and current power loss.

[0034] In this embodiment, the initial steady-state temperature can be specifically understood as the temperature value of the motor controller in the initial steady state, during which the motor controller does not generate heat; the current temperature difference can be specifically understood as the difference between the current temperature and the initial steady-state temperature; the previous temperature difference can be specifically understood as the difference between the previous temperature and the initial steady-state temperature. The current dynamic thermal resistance can be specifically understood as the thermal resistance value at the current moment of estimating the vehicle's coolant flow rate.

[0035] Specifically, for each current temperature and its corresponding previous temperature, the difference is calculated, and the current dynamic thermal resistance is also calculated. The difference between the current temperature and the initial steady-state temperature is taken as the current temperature difference, and the difference between the previous temperature and the initial steady-state temperature is taken as the previous temperature difference. A thermal network model is pre-constructed, and the relationships between the parameters in the thermal network model are analyzed. The current temperature difference, the previous temperature difference, and the corresponding current power loss are substituted into the model to obtain the current dynamic thermal resistance. For each current temperature and each previous temperature, a corresponding current dynamic thermal resistance can be determined.

[0036] S103. Determine the current coolant flow rate based on the current dynamic thermal resistance.

[0037] In this embodiment, the current coolant flow rate can be specifically understood as the flow rate of the vehicle's coolant during the current estimation cycle. A mapping relationship between dynamic thermal resistance and coolant flow rate is pre-established. This mapping relationship can be a direct correspondence between dynamic thermal resistance and coolant flow rate, or a correspondence obtained through calculation based on parameters. The coolant flow rate corresponding to the current dynamic thermal resistance is determined through this mapping relationship. The current coolant flow rate is calculated based on each coolant flow rate, for example, by taking the average value, maximum value, minimum value, or using a weighted calculation.

[0038] This application provides a method for estimating vehicle coolant flow rate. It acquires at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss. For each current temperature, previous temperature, and current power loss, it determines the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature. It then determines the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference, and the current power loss. The current coolant flow rate is then determined based on these current dynamic thermal resistances. This method solves the problems of high cost and large workload in vehicle coolant flow rate measurement. By comparing the temperature of the motor controller with the initial steady-state temperature to determine the temperature difference, and calculating the current dynamic thermal resistance based on the temperature difference and power loss, the current coolant flow rate is estimated. This provides real-time and accurate estimation of coolant flow rate without the need for a flow sensor, is not limited by mechanical installation, has low cost, and is applicable to any situation.

[0039] Example 2

[0040] Figure 2 This is a flowchart of a vehicle-mounted coolant flow estimation method provided in Embodiment 2 of the present invention. This embodiment is a refinement based on the above embodiments. Figure 2 As shown, the method includes:

[0041] S201. Obtain at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss.

[0042] S202. For each current temperature, previous temperature, and current power loss, determine the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature.

[0043] As an optional embodiment of this example, this optional embodiment further optimizes the step of determining the initial steady-state temperature, including the following steps:

[0044] A1. Obtain the total power of the motor controller.

[0045] The total power of the motor controller can be calculated using voltage and current values, and the total power of the motor controller can be monitored in real time. When the motor controller is for a three-phase motor, the total power of the motor controller is the sum of the power of each phase.

[0046] A2. When the total power meets the steady-state condition, determine that the motor controller is in the initial steady state, obtain the temperature of the motor controller, and determine the temperature as the initial steady-state temperature.

[0047] In this embodiment, the steady-state condition can be specifically understood as the condition used to determine whether the motor controller is in an initial stable state. It is determined whether the total power meets the steady-state condition. If it does, the motor controller does not heat up, and the motor controller is determined to be in an initial stable state. The temperature of the motor controller at this moment is obtained and determined as the initial steady-state temperature.

[0048] Furthermore, the steady-state condition is that the total power is lower than a preset power threshold within a preset time range.

[0049] In this embodiment, the preset time range can be set according to actual conditions. Since the electrical response is relatively fast, a shorter duration is selected for the preset time range in this application, such as 2ms or 10ms. The preset power threshold can be determined based on the power value of the motor controller when it is not heating up. The preset power threshold can be determined through multiple experimental measurements.

[0050] When determining whether the total power meets the steady-state condition, this application checks whether the total power is less than a preset power threshold after each acquisition. If it is less than the preset power threshold, it is recorded. If the total power acquired within a consecutive preset time range is less than the preset power threshold, the steady-state condition is determined to be met, and the initial steady-state temperature is recorded. This application continuously acquires the total power of the motor controller and updates the initial steady-state temperature in real time.

[0051] S203. Substitute the current temperature difference, the previous temperature difference, and the current power loss into the predetermined dynamic thermal resistance expression to determine the current dynamic thermal resistance.

[0052] In this embodiment, the dynamic thermal resistance expression can be specifically understood as the relationship expression between the dynamic thermal resistance and various parameters determined by the thermal network model. The dynamic thermal resistance expression also includes other parameters, which are used as known parameters in the calculation when estimating the coolant flow rate. The current temperature difference, the previous temperature difference, and the current power loss are substituted into the dynamic thermal resistance expression for calculation to obtain the current dynamic thermal resistance.

[0053] The expression for dynamic thermal resistance is:

[0054]

[0055] Where R is the current dynamic thermal resistance, C is the heat capacity, and P is the current power loss. For the flow estimation period, Given the current temperature difference, This is the previous temperature difference.

[0056] In this embodiment, C and The flow estimation period can be determined before calculation; it is the same as the period for estimating the vehicle's coolant flow rate. This application takes the periodic cyclic estimation of vehicle coolant flow rate as an example. If the vehicle coolant flow rate estimation does not use a periodic cyclic estimation method, The time interval between two estimations can be used, that is, the time interval between the current estimation time and the previous estimation time. The heat capacity C in this application is determined according to the motor controller, and different motor controllers correspond to different heat capacities C.

[0057] This application provides a method for determining the dynamic thermal resistance expression by constructing a thermal network model. Figure 3 An example diagram of a thermal network model is provided, such as... Figure 3 As shown, thermal resistance R is analogous to resistor, thermal capacity C is analogous to capacitor, power loss P (heat flow) is analogous to current, and temperature T is analogous to voltage. Figure 4 A temperature response curve is provided, showing the temperature response curve after applying a heat flux, as shown below. Figure 4 As shown, Figure 4 The horizontal axis represents time t (in seconds), and the vertical axis represents temperature T (in degrees Celsius).

[0058] Based on the above model, the equation for the first-order RCL filter circuit is:

[0059]

[0060] Where X(k) is the input, Y(k) is the output, and a is the transfer function of the low-pass filter. If Y(0) = 0, then the above equation can be rewritten as:

[0061]

[0062] In the heat network model, let , , Let T be the temperature, P be the power loss, and R be the dynamic thermal resistance. Substituting these values ​​into the above formula, we can obtain the expression for the dynamic thermal resistance as follows:

[0063]

[0064] Where R is the current dynamic thermal resistance, C is the heat capacity, and P is the current power loss. For the flow estimation period, Given the current temperature difference, This is the previous temperature difference.

[0065] S204. Locate the predetermined flow rate and thermal resistance change curve to determine the coolant flow rate corresponding to each current dynamic thermal resistance.

[0066] The flow rate versus thermal resistance curve is predetermined, describing the relationship between dynamic thermal resistance and onboard coolant flow rate. This curve can be expressed as a function, establishing a one-to-one mapping between dynamic thermal resistance and onboard coolant flow rate. Different dynamic thermal resistances and coolant flow rates are pre-determined, generating and storing the flow rate versus thermal resistance curves. After determining the current dynamic thermal resistance, the flow rate versus thermal resistance curve is retrieved to determine the corresponding coolant flow rate. For example, the current dynamic thermal resistance is substituted into the expression of the curve to calculate the coolant flow rate for each current dynamic thermal resistance.

[0067] S205. Determine the current coolant flow rate based on the flow rates of each coolant.

[0068] The calculations are performed based on the various coolant flow rates, such as calculating the average, maximum, and minimum values, and weighted summation, to obtain the current coolant flow rate and ensure the accuracy of the estimation.

[0069] It should be noted that when calculating the current coolant flow rate, this application can also perform calculations based on the current dynamic thermal resistances, such as calculating the average value, maximum value, minimum value, weighted summation, etc., to obtain a dynamic thermal resistance. This dynamic thermal resistance is combined with the flow rate and thermal resistance change curve to determine the coolant flow rate, and this coolant flow rate is used as the current coolant flow rate.

[0070] As an optional embodiment of this example, this optional embodiment further optimizes the steps for forming the flow rate versus thermal resistance curve, including the following steps:

[0071] B1. Determine the target coolant flow rate for the preset quantity.

[0072] In this embodiment, the preset quantity can be set according to actual conditions. The larger the preset quantity, the higher the accuracy of the determined flow rate versus thermal resistance curve. The target coolant flow rate can be specifically understood as a pre-determined coolant flow rate. The cooling system is controlled by the target coolant flow rate to cool the motor drive system. The target coolant flow rate can be set by the user or automatically generated according to actual engineering needs, and the preset quantity can be set by the user. A set of target coolant flow rates can be pre-formed and stored, with elements in the set greater than or equal to the preset quantity. When determining the flow rate versus thermal resistance curve, the preset quantity of target coolant flow rates is selected from the set, or the target coolant flow rate input by the user can be directly received.

[0073] B2. Control the coolant flow rate according to each target coolant flow rate, and determine the target dynamic thermal resistance corresponding to each target coolant flow rate.

[0074] In this embodiment, the target dynamic thermal resistance can be specifically understood as the dynamic thermal resistance value corresponding to cooling under target coolant flow rate. The cooling system is controlled to operate according to the target coolant flow rate, ensuring the coolant is discharged at the target flow rate, and the target dynamic thermal resistance of the motor controller is determined at this point. The target dynamic thermal resistance can be obtained directly or indirectly through electronic devices.

[0075] The target coolant flow rate in this application can be selected from the target coolant flow rate under different operating conditions, and the target dynamic thermal resistance under different operating conditions can be collected.

[0076] B3. Perform curve fitting on the target coolant flow rate and target dynamic thermal resistance to obtain the curves of flow rate and thermal resistance change.

[0077] After determining the target dynamic thermal resistance corresponding to each target coolant flow rate, curve fitting is performed. The fitting method can be an analytical expression approximation of discrete data, the least squares method, etc. The curve of flow rate versus thermal resistance is obtained through curve fitting.

[0078] With a fixed power loss, the larger the cooling water flow rate, the smaller the thermal resistance. When the water flow rate is extremely high, the thermal resistance is almost zero. Conversely, the smaller the cooling water flow rate, the larger the thermal resistance. When the water flow rate is extremely low, the thermal resistance is extremely high.

[0079] This application provides a method for estimating vehicle coolant flow rate. It determines the dynamic thermal resistance expression by constructing a thermal network model, calculates the current dynamic thermal resistance by combining the current temperature difference, the previous temperature difference, and the corresponding current power loss with the dynamic thermal resistance expression, and determines the coolant flow rate corresponding to each current dynamic thermal resistance through the flow rate versus thermal resistance change curve. Then, it determines the current coolant flow rate based on each coolant flow rate. This method solves the problems of high cost and large workload in vehicle coolant flow rate measurement, providing real-time and accurate estimation of coolant flow rate, ensuring the accuracy of coolant flow rate estimation. Furthermore, the method is simple to implement, requires no flow sensor installation, is not limited by mechanical installation constraints, has low cost, and can be applied to any situation.

[0080] Example 3

[0081] Figure 5 This is a schematic diagram of a vehicle-mounted coolant flow estimation device provided in Embodiment 3 of the present invention. Figure 5 As shown, the device includes: a temperature acquisition module 31, a current thermal resistance determination module 32, and a current flow rate determination module 33.

[0082] The temperature acquisition module 31 is used to acquire at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss.

[0083] The current thermal resistance determination module 32 is used to determine the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature for each current temperature, the previous temperature and the current power loss, and to determine the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference and the current power loss.

[0084] The current flow rate determination module 33 is used to determine the current coolant flow rate based on the current dynamic thermal resistance.

[0085] This application provides an on-board coolant flow estimation device that solves the problems of high cost and large workload in on-board coolant flow measurement. It compares the temperature of the motor controller with the initial steady-state temperature to determine the temperature difference. Based on the temperature difference and power loss, it calculates the current dynamic thermal resistance and then estimates the current coolant flow based on the current dynamic thermal resistance. This allows for real-time and accurate estimation of coolant flow. It does not require the installation of a flow sensor, is not limited by the installation of mechanical structures, has a low cost, and can be applied to any occasion.

[0086] Optionally, the device may also include:

[0087] A power acquisition module is used to acquire the total power of the motor controller;

[0088] The steady-state temperature determination module is used to determine that the motor controller is in an initial steady state when the total power meets the steady-state conditions, obtain the temperature of the motor controller, and determine the temperature as the initial steady-state temperature.

[0089] Optionally, the steady-state condition is that the total power is lower than a preset power threshold within a preset time range.

[0090] Optionally, the current thermal resistance determination module 32 is specifically used to: input the current temperature difference, the previous temperature difference, and the current power loss into the pre-determined dynamic thermal resistance expression to determine the current dynamic thermal resistance.

[0091] Optionally, the expression for the dynamic thermal resistance is:

[0092] ;

[0093] Where R is the current dynamic thermal resistance, C is the heat capacity, and P is the current power loss. For the flow estimation period, Given the current temperature difference, This is the previous temperature difference.

[0094] Optionally, the current traffic determination module 33 includes:

[0095] The curve lookup unit is used to find a predetermined curve of change between flow rate and thermal resistance, and to determine the coolant flow rate corresponding to each current dynamic thermal resistance.

[0096] A flow rate determination unit is used to determine the current coolant flow rate based on the flow rates of each coolant.

[0097] Optionally, the device may also include:

[0098] The target flow rate determination module is used to determine a preset target coolant flow rate;

[0099] The target thermal resistance determination module is used to control the coolant flow rate according to the target coolant flow rate and determine the target dynamic thermal resistance corresponding to the target coolant flow rate.

[0100] The curve generation module is used to perform curve fitting on the target coolant flow rate and target dynamic thermal resistance to obtain the change curve of flow rate and thermal resistance.

[0101] The vehicle coolant flow estimation device provided in this embodiment of the invention can execute the vehicle coolant flow estimation method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0102] Example 4

[0103] Figure 6 A schematic diagram of a vehicle structure that can be used to implement embodiments of the present invention is shown. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0104] like Figure 6 As shown, the vehicle includes a temperature sensor 40, at least one processor 41, and a memory, such as a read-only memory (ROM) 42 or a random access memory (RAM) 43, communicatively connected to the at least one processor 41. The temperature sensor can be multiple, or it can be a single sensor capable of simultaneously acquiring multiple temperatures. The memory stores a computer program executable by the at least one processor. The processor 41 can perform various appropriate actions and processes based on the computer program stored in the ROM 42 or loaded from storage unit 48 into the RAM 43. The RAM 43 can also store various programs and data required for vehicle operation. The processor 41, ROM 42, and RAM 43 are interconnected via a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0105] Multiple components in the vehicle are connected to the I / O interface 45, including: input units 46, such as a keyboard, mouse, etc.; output units 47, such as various types of displays, speakers, etc.; storage units 48, such as disks, optical discs, etc.; and communication units 49, such as network cards, modems, wireless transceivers, etc. The communication unit 49 allows the vehicle to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0106] Processor 41 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 41 performs the various methods and processes described above, such as the vehicle coolant flow estimation method.

[0107] In some embodiments, the vehicle coolant flow estimation method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 48. In some embodiments, part or all of the computer program may be loaded into and / or installed in the vehicle via ROM 42 and / or communication unit 49. When the computer program is loaded into RAM 43 and executed by processor 41, one or more steps of the vehicle coolant flow estimation method described above may be performed. Alternatively, in other embodiments, processor 41 may be configured to perform the vehicle coolant flow estimation method by any other suitable means (e.g., by means of firmware).

[0108] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0109] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0110] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0111] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0112] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0113] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0114] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0115] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for estimating vehicle-mounted coolant flow rate, characterized in that, include: Obtain at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss; For each current temperature, previous temperature, and current power loss, the current temperature difference and previous temperature difference are determined based on the current temperature and previous temperature combined with the initial steady-state temperature, and the current dynamic thermal resistance is determined based on the current temperature difference, previous temperature difference, and current power loss. The current coolant flow rate is determined based on the current dynamic thermal resistance described above. The step of determining the initial steady-state temperature includes: Obtain the total power of the motor controller; When the total power meets the steady-state condition, the motor controller is determined to be in an initial steady state. The temperature of the motor controller is obtained and determined as the initial steady-state temperature. The steady-state condition is that the total power is lower than a preset power threshold within a preset time range.

2. The method according to claim 1, characterized in that, The step of determining the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference, and the current power loss includes: The current temperature difference, the previous temperature difference, and the current power loss are substituted into the predetermined dynamic thermal resistance expression to determine the current dynamic thermal resistance.

3. The method according to claim 2, characterized in that, The expression for the dynamic thermal resistance is: Where R is the current dynamic thermal resistance, C is the heat capacity, and P is the current power loss. For the flow estimation period, Given the current temperature difference, This is the previous temperature difference.

4. The method according to claim 1, characterized in that, The step of determining the current coolant flow rate based on the current dynamic thermal resistance includes: Find the predetermined flow rate and thermal resistance change curve, and determine the coolant flow rate corresponding to each current dynamic thermal resistance; The current coolant flow rate is determined based on the coolant flow rate described above.

5. The method according to claim 4, characterized in that, The steps for forming the flow rate versus thermal resistance curve include: Determine the target coolant flow rate for the preset quantity; Coolant flow control is performed based on the target coolant flow rate, and the target dynamic thermal resistance corresponding to each target coolant flow rate is determined. Curve fitting was performed on the target coolant flow rate and target dynamic thermal resistance to obtain the curves of flow rate versus thermal resistance.

6. A vehicle-mounted coolant flow estimation device, characterized in that, include: The temperature acquisition module is used to acquire at least one current temperature corresponding to the motor controller, the previous temperature corresponding to each current temperature, and the current power loss. The current thermal resistance determination module is used to determine the current temperature difference and the previous temperature difference based on the current temperature and the previous temperature combined with the initial steady-state temperature for each current temperature, the previous temperature and the current power loss, and to determine the current dynamic thermal resistance based on the current temperature difference, the previous temperature difference and the current power loss. The current flow rate determination module is used to determine the current coolant flow rate based on the current dynamic thermal resistance. The device further includes: A power acquisition module is used to acquire the total power of the motor controller; The steady-state temperature determination module is used to determine that the motor controller is in an initial steady state when the total power meets the steady-state conditions, obtain the temperature of the motor controller, and determine the temperature as the initial steady-state temperature. The steady-state condition is that the total power is lower than a preset power threshold within a preset time range.

7. A vehicle, characterized in that, The vehicles include: A temperature sensor is used to collect the current temperature; At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the vehicle coolant flow estimation method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the vehicle coolant flow estimation method according to any one of claims 1-5.

Images