Ambient temperature estimation method and vehicle

Abstract

The invention relates to an environment temperature estimation method and a vehicle, and the environment temperature estimation method comprises the steps: under the condition that the vehicle is detected to enter a power-on state and an environment temperature sensor of the vehicle fails, detecting that the environment temperature sensor of the vehicle fails after the power-on moment; whether signals of an intake air temperature sensor and a supercharger temperature sensor of an engine of the vehicle are valid; and if respective signals of an air inlet temperature sensor and a supercharger temperature sensor of an engine of the vehicle are valid after the power-on moment, determining an environment temperature estimated value of the vehicle after the power-on moment according to respective sensor data of the air inlet temperature sensor and the supercharger temperature sensor. According to the method, the environment temperature can be estimated according to the air inlet temperature sensor and the supercharger temperature sensor on the air inlet path of the engine, and therefore environment temperature information input of the hybrid power system can still be guaranteed under the condition that the environment temperature sensor fails.

Description

Technical Field

[0001] This application relates to the field of hybrid vehicles, and in particular to methods for estimating ambient temperature and vehicles. Background Technology

[0002] Currently, to meet the demands of energy conservation and emission reduction, the automotive industry is accelerating its shift towards electrification. However, the large-scale adoption of pure electric vehicles still faces challenges due to factors such as battery costs and technological complexity. This has led to widespread attention and application of hybrid systems, especially highly integrated dual-motor hybrid systems, in the automotive field.

[0003] Figure 1 This is a schematic diagram of a dual-motor hybrid power system. Please refer to [link / reference]. Figure 1 The hybrid power system includes an engine, a battery, a ratio system for system diagnostics and control, a clutch C0, an electric motor P1, and an electric motor P2. Through the coordination of clutch C0, the hybrid system can achieve multiple operating modes, including pure electric, series, and parallel operation, to adapt to complex driving conditions. In series mode, P2 drives the wheels, clutch C0 is not engaged, and the engine charges the battery through P1. In parallel mode, clutch C0 is engaged, and the engine directly drives the wheels.

[0004] The control accuracy of the aforementioned hybrid power system is highly dependent on the input signals from various sensors, among which ambient temperature is one of the key parameters. Ambient temperature is not only used to adjust the thermal management control strategies of the engine, battery, and motor, but also directly affects the vehicle's driving safety and ride comfort.

[0005] Currently, related technologies typically rely on ambient temperature sensors to directly obtain the vehicle's ambient temperature. When the ambient temperature sensor malfunctions or its signal is distorted, the vehicle control system will lose an accurate temperature reference and be unable to make effective corrections, leading to decreased system performance, increased energy consumption, and even safety hazards. Therefore, there is currently no effective solution for ensuring the input of ambient temperature information for hybrid power system control in the event of ambient temperature sensor failure. Summary of the Invention

[0006] This embodiment provides an ambient temperature estimation method and a vehicle to solve the problem in related technologies where accurate input of ambient temperature information for hybrid power system control is impossible when the ambient temperature sensor fails.

[0007] In a first aspect, this embodiment provides an ambient temperature estimation method for hybrid vehicles, the method comprising:

[0008] If the vehicle is detected to be powered on and the vehicle's ambient temperature sensor is malfunctioning, the system checks whether the signals of the vehicle's engine intake air temperature sensor and turbocharger temperature sensor are valid after the power-on time.

[0009] If the signals from the engine intake temperature sensor and the turbocharger temperature sensor of the vehicle are both valid after the power-on time, then the estimated ambient temperature of the vehicle after the power-on time is determined based on the sensor data of the intake temperature sensor and the turbocharger temperature sensor.

[0010] In some embodiments, determining an estimated ambient temperature of the vehicle after power-on based on sensor data from the intake air temperature sensor and the turbocharger temperature sensor includes:

[0011] The minimum value between the sensor data of the intake air temperature sensor and the sensor data of the turbocharger temperature sensor at the non-power-on time will be used as the estimated value of the ambient temperature at the non-power-on time; the non-power-on time is the time when the vehicle is in operation after the power-on time.

[0012] In some embodiments, when the signal from the intake air temperature sensor is invalid after the power-on time, and / or the signal from the turbocharger temperature sensor is invalid, the method further includes:

[0013] Obtain the pre-stored historical temperature estimates;

[0014] The minimum value among the intake air temperature sensor data at the non-power-on time, the turbocharger temperature sensor data at the non-power-on time, and the estimated ambient temperature at the historical time is determined as the estimated ambient temperature at the non-power-on time.

[0015] In some embodiments, the method further includes:

[0016] When the vehicle is detected to be powered on and the ambient temperature sensor fails, the sensor data of the intake air temperature sensor at the time of power-on, the sensor data of the turbocharger temperature sensor at the time of power-on, and the pre-stored estimated values ​​of the ambient temperature at historical times are acquired.

[0017] The minimum value between the intake air temperature sensor data at the power-on moment and the turbocharger temperature sensor data at the power-on moment is used as the comparison value; the estimated ambient temperature value at the historical moment is used as the basic value.

[0018] Furthermore, a temperature rise limit is determined; the temperature rise limit represents the allowable temperature rise between the power-on time and the historical time under different downtime of the vehicle.

[0019] Determine whether the temperature difference between the value to be compared and the baseline value is less than or equal to the temperature rise limit; if so, use the temperature difference as an increment.

[0020] The sum of the basic value and the incremental value is used as the estimated ambient temperature at the time of power-on.

[0021] In some embodiments, the method further includes:

[0022] When the temperature difference is greater than the temperature rise limit, the temperature rise limit is taken as an increment.

[0023] The sum of the basic value and the incremental value is used as the estimated ambient temperature at the time of power-on.

[0024] In some of these embodiments, determining the temperature rise limit includes:

[0025] Obtain the downtime of the vehicle;

[0026] Based on the vehicle's downtime, a temperature rise limit corresponding to the vehicle's downtime is determined from a preset mapping relationship between different downtimes and different temperature rise limits; the temperature rise limit in the mapping relationship increases as the downtime increases.

[0027] In some embodiments, detecting whether the signal from the vehicle's engine intake air temperature sensor is valid after power-on includes:

[0028] When the intake air flow rate of the engine is less than a preset low flow rate threshold, the signal of the intake air temperature sensor is determined to be invalid.

[0029] When the cumulative intake airflow of the engine within a preset time period is less than a preset cumulative threshold, the signal of the intake air temperature sensor is determined to be invalid; the cumulative threshold represents the intake airflow required to cool the intake air temperature sensor.

[0030] In some embodiments, determining whether the signal from the turbocharger temperature sensor of the vehicle's engine is valid after power-on includes:

[0031] When the vehicle speed is greater than a preset first speed threshold and less than or equal to a preset second speed threshold, and the turbocharger outlet pressure is within a preset first pressure range, the signal of the turbocharger temperature sensor is determined to be valid; the first pressure range represents the turbocharger outlet pressure range when the engine is under low load; the first speed threshold is less than the second speed threshold; the first speed threshold represents the minimum speed value for the vehicle to transition from a stationary state to a moving state; the second speed threshold represents the minimum speed value for the vehicle to enter a driving state.

[0032] When the vehicle speed is greater than the second speed threshold and the turbocharger outlet pressure is within a preset second pressure range, the signal of the turbocharger temperature sensor is determined to be valid; the value within the second pressure range is greater than the value within the first pressure range; the second pressure range characterizes the turbocharger outlet pressure range when the engine is under high load.

[0033] In some embodiments, the method further includes:

[0034] The estimated ambient temperature is filtered to obtain the target ambient temperature value after the vehicle is powered on and running.

[0035] Secondly, this embodiment provides a vehicle including a memory and a processor, the memory storing a computer program, and the processor being configured to run the computer program to perform the ambient temperature estimation method described in the first aspect above.

[0036] Compared with related technologies, this embodiment provides an ambient temperature estimation method and a vehicle. The ambient temperature estimation method first detects that the vehicle has entered a powered-on state and that the vehicle's ambient temperature sensor has failed. Then, it checks whether the signals of the engine's intake air temperature sensor and the turbocharger temperature sensor are valid after the power-on moment. If the signals of both sensors are valid after the power-on moment, the estimated ambient temperature after the power-on moment is determined based on the sensor data. This method can estimate the ambient temperature based on the intake air temperature sensor and turbocharger temperature sensor along the engine's intake path, thus ensuring the input of ambient temperature information for the hybrid power system even when the ambient temperature sensor fails.

[0037] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0039] Figure 1 This is a schematic diagram of a dual-motor hybrid power system.

[0040] Figure 2 This is a hardware structure block diagram of the terminal of the environmental temperature estimation method according to an embodiment of this application;

[0041] Figure 3 This is a flowchart of the environmental temperature estimation method according to an embodiment of this application;

[0042] Figure 4 This is a flowchart of an environmental temperature estimation method according to some embodiments of this application. Detailed Implementation

[0043] To better understand the purpose, technical solution, and advantages of this application, the application is described and explained below in conjunction with the accompanying drawings and embodiments.

[0044] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order of objects.

[0045] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. For example, it can run on a terminal. Figure 2 This is a hardware structure block diagram of the terminal for the ambient temperature estimation method in this embodiment. For example... Figure 2 As shown, a terminal may include one or more ( Figure 2 Only one is shown in the diagram. A processor 202 and a memory 204 for storing data are also included. The processor 202 may be, but is not limited to, a microprocessor (MCU) or a programmable logic device (FPGA). The terminal may also include a transmission device 206 for communication functions and an input / output device 208. Those skilled in the art will understand that… Figure 2 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 2 The more or fewer components shown, or having the same Figure 2 The different configurations shown are illustrated.

[0046] The memory 204 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the ambient temperature estimation method in this embodiment. The processor 202 executes various functional applications and data processing by running the computer programs stored in the memory 204, thereby implementing the aforementioned method. The memory 204 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 204 may further include memory remotely located relative to the processor 202, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0047] The transmission device 206 is used to receive or send data via a network. This network includes a wireless network provided by the terminal's communication provider. In one example, the transmission device 206 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 206 can be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0048] This embodiment provides an environmental temperature estimation method. Figure 3 This is a flowchart of the environmental temperature estimation method in this embodiment, as shown below. Figure 3 As shown, the process includes the following steps:

[0049] Step S310: If the vehicle is detected to be powered on and the vehicle's ambient temperature sensor is malfunctioning, check whether the signals of the vehicle's engine intake air temperature sensor and turbocharger temperature sensor are valid after the power-on moment.

[0050] The ambient temperature prediction based on the intake air temperature sensor and turbocharger temperature sensor is triggered by the vehicle's power-on process when the ambient temperature sensor has failed. Specifically, the vehicle is confirmed to be powered on when the ignition switch changes from inactive to active, or when the vehicle's electrical system is activated. The ambient temperature sensor can be located at the front of the vehicle, exposed to flowing air but protected from direct sunlight and road heat radiation; this sensor detects the ambient temperature. The intake air temperature sensor can be located in the engine's intake manifold, or integrated with other engine sensors, such as a flow meter or intake pressure sensor; this sensor detects the temperature of the air entering the engine. The turbocharger temperature sensor can be located at the intercooler outlet to measure the temperature of the compressed air after turbocharging and intercooler cooling.

[0051] After the vehicle is powered on and running, the ambient temperature can be estimated periodically. Each time an ambient temperature estimate is performed, the validity of the signals from the intake air temperature sensor and the turbocharger temperature sensor is first determined. A valid intake air temperature sensor signal indicates that its data accurately reflects the ambient temperature; similarly, a valid turbocharger temperature sensor signal indicates that its data accurately reflects the ambient temperature. During vehicle operation, as vehicle operating conditions change, the temperature data collected by the intake air temperature sensor and turbocharger temperature sensor may be affected, resulting in the collected temperature data being higher than the actual ambient temperature. For example, when the engine intake air volume is too high and the engine is under high load, the turbocharger temperature rises. In this case, the ambient temperature reflected by the turbocharger temperature sensor is not accurate enough, and the ambient temperature estimate cannot be directly based on the temperature value reflected by the turbocharger temperature sensor.

[0052] Therefore, it is necessary to first determine the validity of the signals from the intake air temperature sensor and the turbocharger temperature sensor. Specifically, this can be done based on vehicle operating conditions, such as vehicle speed, turbocharger outlet pressure, and engine gas flow rate, to determine whether the signals from the intake air temperature sensor and the temperature sensor are valid at that time.

[0053] Step S320: If the signals of the engine intake temperature sensor and the turbocharger temperature sensor are both valid after the power-on time, then the estimated ambient temperature of the vehicle after the power-on time is determined based on the sensor data of the intake temperature sensor and the turbocharger temperature sensor.

[0054] Once the signals from the engine's intake air temperature sensor and turbocharger temperature sensor are confirmed to be valid after power-on, the estimated ambient temperature at that specific moment can be determined based on the sensor data collected by the intake air temperature sensor and turbocharger temperature sensor at the same time after power-on. Specifically, this can be achieved by statistically processing the temperature values ​​collected by the intake air temperature sensor and turbocharger temperature sensor at a given time t, and using the result as the estimated ambient temperature for that time t. Alternatively, the minimum value of the temperature values ​​corresponding to the intake air temperature sensor and turbocharger temperature sensor at a given time t can be used as the estimated ambient temperature for that time t.

[0055] In related technologies, ambient temperature sensors are often used to directly acquire the vehicle's ambient temperature signal as one of the input parameters for the vehicle's hybrid power system. When the ambient temperature sensor malfunctions or its signal is distorted, it will result in the inability to obtain accurate ambient temperature values, thereby affecting system performance, increasing energy consumption, and even causing safety hazards.

[0056] To address this, this embodiment, based on steps S310 to S320 above, enables ambient temperature estimation using the engine's intake air temperature sensor and turbocharger temperature sensor in the event of an ambient temperature sensor failure. Since the intake air temperature sensor and turbocharger temperature sensor collect the gas temperature along the engine's intake path, when their temperature measurements are unaffected by vehicle operating conditions, the temperatures they collect are relatively close to the actual ambient temperature; that is, they can indicate temperatures comparable to the ambient temperature. Therefore, in the ambient temperature assessment phase after vehicle power-on, this embodiment first determines whether the signals from the intake air temperature sensor and turbocharger temperature sensor are valid. If both signals are confirmed to be valid, the ambient temperature is estimated based on the individual sensor data from the intake air temperature sensor and turbocharger temperature sensor. Therefore, this embodiment can replace the value collected by the ambient temperature sensor with the value of the ambient temperature sensor by estimating the ambient temperature when the ambient temperature sensor fails. This allows the system to continue to input accurate ambient temperature data to maintain the stability of the hybrid system and thus improve the safety and reliability of the vehicle.

[0057] Through steps S310 to S320 above, when the vehicle is detected to be powered on and the vehicle's ambient temperature sensor fails, the system checks whether the signals of the engine's intake air temperature sensor and the turbocharger temperature sensor are valid after the power-on moment. If the signals of both sensors are valid after the power-on moment, the estimated ambient temperature after the power-on moment is determined based on their respective sensor data. This system can estimate the ambient temperature based on the intake air temperature sensor and turbocharger temperature sensor along the engine's intake path, thus ensuring the input of ambient temperature information for the hybrid power system even when the ambient temperature sensor fails.

[0058] In one embodiment, based on step S320 above, the estimated ambient temperature of the vehicle after power-on is determined according to the sensor data of the intake air temperature sensor and the turbocharger temperature sensor, which may specifically include:

[0059] The minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data at the non-power-on time will be used as the estimated ambient temperature at the non-power-on time; the non-power-on time is the time when the vehicle is in operation after the power-on time.

[0060] The non-power-on time can be any moment after the power-on time when the vehicle is in operation. For example, any moment in a driving state or a temporarily stopped state. During the non-power-on time, assuming the signals from both the intake air temperature sensor and the turbocharger temperature sensor are valid, the minimum value between the data from the intake air temperature sensor and the turbocharger temperature sensor can be used as the estimated ambient temperature for that non-power-on time. It is understood that after the vehicle is powered on and started, there can be several non-power-on times. The above-mentioned ambient temperature estimation can be performed for each non-power-on time, thus obtaining multiple estimated ambient temperature values ​​for each non-power-on time. For example, at the non-power-on time t1, based on the temperature value 'a' degrees Celsius (°C) collected by the intake air temperature sensor and the temperature value 'b' degrees Celsius collected by the turbocharger temperature sensor, if 'a' is less than 'b', then 'a' degrees Celsius is used as the estimated ambient temperature value for the non-power-on time t1.

[0061] In this embodiment, it is further considered that even when both the intake air temperature sensor and the turbocharger temperature sensor have valid signals, occasional fluctuations due to engine operation may cause the temperature indicated by the output sensor data to be higher than the actual ambient temperature; and the temperature of the gas entering the engine will be equal to or greater than the actual ambient temperature. Therefore, this embodiment uses the minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data as the estimated ambient temperature at the time of non-power-on. This ensures that the estimated ambient temperature is as close as possible to the actual ambient temperature, thereby improving the accuracy of the ambient temperature estimation.

[0062] Furthermore, in one embodiment, when the intake air temperature sensor signal is invalid after power-on, and / or the turbocharger temperature sensor signal is invalid, the above-mentioned ambient temperature estimation method may further include:

[0063] Obtain the pre-stored ambient temperature estimates from historical moments; determine the minimum value among the intake air temperature sensor data at non-power-on moments, the turbocharger temperature sensor data at non-power-on moments, and the ambient temperature estimates from historical moments as the ambient temperature estimate at non-power-on moments.

[0064] When it is determined that the intake air temperature sensor signal, the turbocharger temperature sensor signal, or both signals are invalid at a certain non-power-on time, a previously estimated ambient temperature value needs to be introduced to help confirm the estimated ambient temperature for that non-power-on time. This historical time is a relative time, specifically the time before the current non-power-on time when the ambient temperature estimation is performed. For example, there are times t2, t3, and t4, where t2 is earlier than t3, and t3 is earlier than t4. Then, t2 can be considered the historical time of t3, and t3 can be considered the historical time of t4. For a given non-power-on time, the corresponding historical time can be the most recent time when the ambient temperature was estimated, which could be either a non-power-on time before the current non-power-on time or a power-on time before the current non-power-on time. Therefore, reading the pre-stored historical ambient temperature estimate specifically means reading the most recently stored ambient temperature estimate.

[0065] After reading the estimated ambient temperature value at a historical moment, the sensor data of the intake air temperature sensor and the turbocharger temperature sensor at the same non-power-on moment can be compared with the estimated ambient temperature value at that historical moment, and the minimum value of the three can be taken as the estimated ambient temperature value at that non-power-on moment.

[0066] In this embodiment, when the signals of the intake air temperature sensor and / or the turbocharger temperature sensor fail, the sensor data of the intake air temperature sensor and the turbocharger temperature sensor may not accurately reflect the ambient temperature. Based on the characteristic that the change range of ambient temperature is relatively small at similar times, the ambient temperature is estimated by introducing the estimated value of ambient temperature at historical times as a reference. This enables a stable estimation of ambient temperature under the influence of vehicle operating conditions, and obtains a temperature estimate that is closer to the actual ambient temperature.

[0067] In another embodiment, the above-described ambient temperature estimation method may further include:

[0068] When the vehicle is detected to be powered on and the ambient temperature sensor is malfunctioning, the system acquires the sensor data from the intake air temperature sensor and the turbocharger temperature sensor at the moment of power-on, as well as pre-stored historical ambient temperature estimates. The minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data at the moment of power-on is used as the comparison value. The historical ambient temperature estimates are used as the baseline value. Furthermore, a temperature rise limit is determined. The temperature rise limit represents the allowable temperature rise between the moment of power-on and the historical time for different vehicle downtimes. The system determines whether the temperature difference between the comparison value and the baseline value is less than or equal to the temperature rise limit. If so, this temperature difference is used as an increment. The sum of the baseline value and the increment is used as the ambient temperature estimate at the moment of power-on.

[0069] When estimating the ambient temperature at the moment the vehicle is powered on, since the vehicle is not yet running, it is impossible to obtain operating condition information reflecting driving conditions such as vehicle speed, outlet pressure, and engine gas flow. Therefore, the ambient temperature estimate at the moment of power-on can be determined by reading historical ambient temperature estimates and combining these historical estimates with sensor data from the intake air temperature sensor and turbocharger temperature sensor at the moment of power-on.

[0070] Specifically, the historical moment of power-on can be the moment when the vehicle last performed an ambient temperature estimate before its most recent shutdown. Understandably, after each calculation of the ambient temperature estimate for a given moment, that estimate can be stored in a preset memory, such as non-volatile random access memory (NVRAM). This memory can store ambient temperature estimates for multiple moments, or it can store only the most recently calculated estimate. For example, when completing an ambient temperature estimate, the previously stored estimate in memory can be updated to the most recently calculated estimate.

[0071] In this embodiment, for the ambient temperature estimation at power-on, it is necessary to introduce the ambient temperature estimate from historical time points and the temperature rise limit to ensure the stability of the ambient temperature estimation. Specifically, when the ignition switch signal is detected to be valid, the minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data at this time is read as the comparison value. Then, the difference between this comparison value and the ambient temperature estimate from historical time points, which serves as the base value, is calculated to determine whether the increase in the comparison value relative to the ambient temperature estimate from historical time points is less than or equal to the temperature rise limit. If so, it is confirmed that the current sensor data can accurately reflect the ambient temperature, and the temperature difference between this comparison value and the base value is taken as the increment. The sum of the base value and the increment is confirmed as the ambient temperature estimate at power-on (that is, at this time, the minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data is taken as the ambient temperature estimate at power-on). It can be understood that when the ignition switch is invalid, this comparison value is set to 0.

[0072] It should also be noted that this temperature rise limit is used to indicate a reasonable temperature difference before and after the vehicle stops for different shutdown durations. The temperature rise limit corresponding to different shutdown durations can be obtained based on actual measurement calibration; or, those skilled in the art can determine the temperature rise limit for different shutdown durations by taking empirical values ​​based on the performance of the hybrid vehicle itself.

[0073] In this embodiment, when estimating the ambient temperature during vehicle startup, sensor temperature rise compensation based on the constraint of a temperature rise limit is implemented. Specifically, considering the possibility of excessively high temperatures from the intake air temperature sensor and the turbocharger temperature sensor during vehicle startup, this embodiment chooses not to directly use the sensor data from the intake air temperature sensor and the turbocharger temperature sensor when estimating the ambient temperature at power-on. Instead, it uses the temperature rise limit corresponding to the vehicle's downtime. Only when the minimum value between the temperatures indicated by the intake air temperature sensor and the turbocharger temperature sensor is less than or equal to the temperature rise limit compared to the last ambient temperature estimate before shutdown, is this minimum value determined as the ambient temperature estimate at power-on. This achieves reasonable constraint on the fluctuation of the ambient temperature estimate and improves the accuracy of the ambient temperature estimate at power-on.

[0074] In another embodiment, the above-described ambient temperature estimation method may further include:

[0075] When the temperature difference exceeds the temperature rise limit, the temperature rise limit is used as the increment; the sum of the base value and the increment is used as the estimated ambient temperature at the time of power-on.

[0076] When the aforementioned temperature difference exceeds the temperature rise limit, it indicates that the temperature difference between the current temperature estimated by the sensors and the estimated ambient temperature before shutdown exceeds the reasonable range for the corresponding shutdown duration. This reflects a significant discrepancy between the temperature values ​​determined by the intake air temperature sensor and the turbocharger temperature sensor and the actual ambient temperature. Therefore, the sum of the historical ambient temperature estimate and the temperature rise limit corresponding to the current power-on moment is used as the ambient temperature estimate at the power-on moment, thereby improving the accuracy of the ambient temperature estimation.

[0077] In one embodiment, determining the aforementioned temperature rise limit may specifically include: obtaining the vehicle's downtime; determining the temperature rise limit corresponding to the vehicle's downtime from a preset mapping relationship between different downtimes and different temperature rise limits based on the vehicle's downtime; the temperature rise limit in the mapping relationship increases with the increase of the downtime.

[0078] The downtime can be specifically the difference between the current power-on time and the calculation time of the latest estimated ambient temperature recorded in the memory. For example, this mapping relationship can have the form shown in Table 1:

[0079] Table 1

[0080]

[0081] The unit for downtime can be seconds; the unit for temperature rise limit can be °C. It is understood that the data shown in Table 1 is merely an example illustrating the mapping relationship between downtime and temperature rise limit, and does not constitute a specific limitation on this mapping relationship. Those skilled in the art can adapt this mapping relationship according to the needs of actual application scenarios.

[0082] In this mapping relationship, the longer the downtime, the higher the corresponding temperature rise limit. That is, when the downtime is short, the allowable rise in the estimated value is small, while when the downtime is long, the allowable rise in the estimated value is large. Therefore, this embodiment can achieve a temperature rise limit setting that conforms to the actual characteristics of ambient temperature changes, thereby achieving a reasonable limitation on the estimated ambient temperature and avoiding high ambient temperature estimation errors.

[0083] Additionally, in some embodiments, based on the above step S310, detecting whether the signal from the vehicle's engine intake air temperature sensor is valid after power-on may specifically include:

[0084] When the engine's intake air flow rate is less than a preset low flow rate threshold, the signal of the intake air temperature sensor is determined to be invalid; when the cumulative value of the engine's intake air flow rate within a preset time period is less than a preset cumulative value threshold, the signal of the intake air temperature sensor is determined to be invalid; the cumulative value threshold represents the intake air flow rate required to cool the intake air temperature sensor.

[0085] When the engine's intake airflow is too low, the temperature signal detected by the intake air temperature sensor cannot accurately reflect the ambient temperature. Furthermore, after the vehicle starts, the intake air temperature sensor needs time to recover to ambient temperature; therefore, a certain amount of air is required to cool it. If, within a preset time period, the accumulated engine intake airflow is less than the amount of gas required to cool the intake air temperature sensor, the sensor may not have recovered to ambient temperature, resulting in a significant difference between the output temperature value and the actual ambient temperature. Therefore, when the engine's intake airflow is less than a preset low flow threshold, or when the accumulated intake airflow within a preset time period is less than a preset accumulated value threshold, the intake air temperature sensor signal is determined to be invalid. Both the flow threshold and the accumulated value threshold can be obtained through actual measurement calibration or empirical values; this embodiment does not impose specific limitations on these.

[0086] This embodiment can assess whether the intake air temperature sensor can accurately reflect the ambient temperature based on the engine's intake air flow, thereby improving the accuracy and stability of ambient temperature estimation.

[0087] In one embodiment, based on the above step S310, determining whether the signal from the turbocharger temperature sensor of the vehicle's engine is valid after power-on may include:

[0088] The signal from the turbocharger temperature sensor is determined to be valid when the vehicle speed is greater than a preset first speed threshold and less than or equal to a preset second speed threshold, and the turbocharger outlet pressure is within a preset first pressure range. The first pressure range represents the turbocharger outlet pressure range when the engine is under low load. The first speed threshold is less than the second speed threshold. The first speed threshold represents the minimum speed at which the vehicle transitions from a stationary state to a moving state. The second speed threshold represents the minimum speed at which the vehicle enters a driving state. The signal from the turbocharger temperature sensor is determined to be valid when the vehicle speed is greater than the second speed threshold and the turbocharger outlet pressure is within a preset second pressure range. The value within the second pressure range is greater than the value within the first pressure range. The second pressure range represents the turbocharger outlet pressure range when the engine is under high load.

[0089] In this embodiment, the presence of airflow within the engine is determined based on the outlet pressure of the engine's turbocharger. When the outlet pressure is too low, it indicates that no airflow enters the engine, and the vehicle may be in a coasting state. Therefore, in this case, the turbocharger temperature sensor cannot accurately indicate the ambient temperature. To address this, a lower limit value (p_MinBoostPres) of a first pressure range can be set based on measured or empirical values. This lower limit value is the minimum boost pressure required for airflow to enter the engine. For example, this lower limit value can be set to 0.5 kPa.

[0090] This embodiment also considers that when the engine load is too high, specifically when the airflow into the engine is large, the boost temperature sensor cannot accurately reflect the ambient temperature. Therefore, based on measured or empirical values, an upper limit value (p_MaxBoostPres) is set for the first pressure range. This upper limit value is the critical value of the outlet pressure indicating when the engine is under high load. For example, this upper limit value can be 100 kPa. Thus, one possible form of the first pressure range is [0.5 kPa, 100 kPa].

[0091] Additionally, when the vehicle is traveling at a high speed, the engine is under high load, resulting in a higher turbocharger outlet pressure. If the vehicle speed does not decrease to a preset threshold, the intercooler will continue cooling the air even with the high outlet pressure. Therefore, if the pressure exceeds the aforementioned upper limit (e.g., 100 kPa) when the vehicle speed exceeds the second speed threshold, the turbocharger temperature sensor signal is also considered valid. For example, this second speed threshold can be set to 2 kilometers per hour (km / h).

[0092] Furthermore, when the vehicle speed is less than or equal to a preset first speed threshold, it is considered that the speed is too low. An excessively low speed may result in poor cooling of the air by the intercooler, leading to a boosted air temperature higher than the actual ambient temperature. Consequently, the temperature reflected by the booster temperature sensor will differ significantly from the actual ambient temperature. In this case, the signal from the booster temperature sensor is considered invalid. This first speed threshold can be the speed at which the vehicle changes from a stationary state to a moving state, for example, 1 km / h.

[0093] In summary, the turbocharger temperature sensor is considered effective when the vehicle speed is between the first speed threshold and the second speed threshold, that is, greater than the first speed threshold and less than or equal to the second speed threshold, and the outlet pressure is within the first pressure range; the turbocharger temperature sensor is considered effective when the vehicle speed is greater than the second speed threshold and the outlet pressure is within the second pressure range.

[0094] In this regard, this embodiment can combine the turbocharger outlet pressure and vehicle speed to accurately identify the signal validity of the turbocharger temperature sensor, thereby avoiding the impact of changes in vehicle driving conditions on the accuracy of ambient temperature estimation and improving the stability of ambient temperature estimation.

[0095] In another embodiment, the above-described ambient temperature estimation method may further include:

[0096] The estimated ambient temperature is filtered to obtain the target ambient temperature value after the vehicle is powered on. This embodiment's ambient temperature estimation method can estimate the ambient temperature at different times, obtaining corresponding estimated values ​​for each time period. The probability of a sudden change in actual ambient temperature within a short period is low. Therefore, if the estimated ambient temperature changes rapidly within a short time, it indicates that the estimated ambient temperature at certain times is inaccurate. Therefore, a filtering coefficient can be introduced to filter the estimated ambient temperature at each time period. Specifically, when the temperature change exceeds a given threshold within a certain time period, the filtering coefficient can be reduced to prevent large differences in the estimated ambient temperature at similar times, thus avoiding large changes in the reflected ambient temperature within a short period.

[0097] To detect the signal validity of the aforementioned turbocharger temperature sensor, it is necessary to monitor the turbocharger's outlet pressure. In some embodiments, a boost monitoring module can be constructed to monitor the turbocharger's pressure. Specifically, monitoring is achieved by comparing the deviation between the actual outlet pressure of the turbocharger and the set target pressure, while simultaneously determining whether the engine is malfunctioning and implementing torque-limiting protection for the engine when the boost pressure is too high.

[0098] Specifically, this system monitors the turbocharger for over-boost and under-boost faults under steady-state conditions, where the engine is not undergoing rapid acceleration or deceleration but rather in a relatively stable and constant operating state (e.g., during cruise control). Monitoring for over-boost and under-boost is achieved by combining the actual boost pressure with the desired target pressure. Different fault codes can be set for over-boost and under-boost. Monitoring the turbocharger under these steady-state conditions may include the acquisition and processing of monitoring signals, activation of monitoring conditions, determination of test values ​​based on the actual boost pressure and the given target pressure, and generation and storage of fault information corresponding to over-boost and under-boost, respectively.

[0099] When acquiring the signals to be monitored, the outlet pressure of the turbocharger is selected as the boost pressure. The difference between the boost pressure and atmospheric pressure is taken as the relative boost pressure. To avoid control deviations caused by insufficient driving force preventing the compressor from reaching the target operating point, a desired boost ratio is determined based on engine torque and speed. This desired boost ratio (the ratio of the limited target boost pressure to atmospheric pressure) is used when the compressor is limited by insufficient driving force. Then, low boost pressure monitoring is achieved by comparing the actual boost pressure ratio (the ratio of the actual boost pressure to atmospheric pressure) with this target boost pressure ratio. Additionally, the difference between the desired target pressure and the actual boost pressure is used as an unrestricted boost pressure control deviation to achieve high boost pressure monitoring.

[0100] Both overpressure and underpressure monitoring can be enabled under specific conditions. Specifically, overpressure monitoring can be enabled under the following conditions: relative boost pressure exceeding a given limit; the difference between the target boost pressure and the actual boost pressure exceeding a given difference limit; engine coolant temperature exceeding a given coolant temperature limit; engine speed exceeding a certain speed limit; and throttle module flow deviation within a given deviation range. Enabling overpressure monitoring only when the relative boost pressure exceeds a given limit ensures that monitoring only begins after the turbocharger has generated boost pressure, preventing false monitoring when the turbocharger lacks sufficient energy to drive the turbine to build boost pressure. Furthermore, monitoring only occurs when the actual boost pressure is close to the target boost pressure to prevent monitoring during the pressure build-up phase from affecting accuracy. Monitoring when the engine coolant temperature exceeds a given coolant temperature limit prevents monitoring under cold engine conditions, where exhaust gas energy is primarily used for heating rather than driving the turbine. Additionally, overpressure monitoring can be stopped even with exhaust gas completely shut off if the engine speed is insufficient to generate excessive pressure from the turbocharger. Furthermore, when a significant throttle flow deviation occurs, monitoring for excessive pressure will cease once this deviation exceeds a certain range. This is because a large throttle flow deviation can cause a pressure spike before the throttle valve, which may lead to false alarms about excessive boost pressure.

[0101] Enabling conditions for low-pressure monitoring can include: engine coolant temperature exceeding a given limit, a low-boost steady-state condition, and a closed compressor bypass valve. The engine coolant temperature limit is to prevent low-pressure monitoring under cold engine conditions, where exhaust gas energy is primarily used for heating rather than driving the turbine. The low-boost steady-state condition can include engine speed exceeding a given speed limit and the difference between the target pressure and the current ambient pressure exceeding a given pressure limit; that is, the desired target pressure is sufficiently high. Furthermore, monitoring is disabled when the compressor bypass valve is open.

[0102] When the overpressure monitoring condition is met, the system determines whether overpressure exists based on the actual boost pressure and the given target boost pressure. When the underpressure monitoring condition is met, the system determines whether underpressure exists based on the actual boost pressure and the given target boost pressure. This can be achieved by averaging the deviation. Afterwards, the monitoring results and report status are sent to the designated monitoring core, and the monitoring results are categorized, with a trigger set for Integral Performance Ratio (IUPR) calculation. When overpressure or underpressure is determined, the results are calculated in a categorized manner. Depending on the categorization, if overpressure or underpressure would damage the engine, a reconfiguration is activated to reduce the available boost energy by limiting torque, thereby reducing boost pressure. For example, monitoring for failures where the relative boost pressure exceeds a certain boost limit, which represents the maximum pressure the intake system can handle, can be set to, for example, 199 kPa. If the boost pressure exceeds this boost pressure limit for a certain period of time, such as 80 milliseconds (ms) to 120 ms, measures will be taken to reduce the boost pressure to below this boost pressure limit.

[0103] Figure 4 This is a flowchart of one of the embodiments of the environmental temperature estimation method, such as Figure 4 As shown, the environmental temperature estimation method includes the following steps:

[0104] Step S401: When the vehicle is detected to be powered on and the ambient temperature sensor of the vehicle is malfunctioning, the sensor data of the intake air temperature sensor at the moment of power-on, the sensor data of the turbocharger temperature sensor at the moment of power-on, and the pre-stored estimated values ​​of the ambient temperature at historical moments are acquired.

[0105] Step S402: Based on the data obtained in step S401, calculate the estimated ambient temperature at the time of power-on. The minimum value between the intake air temperature sensor data and the turbocharger temperature sensor data at the time of power-on is used as the comparison value at the time of power-on. Obtain the vehicle's downtime. Based on the vehicle's downtime, determine the temperature rise limit corresponding to the vehicle's downtime from a preset mapping relationship between different downtimes and different temperature rise limits. Determine whether the temperature difference between the comparison value and the estimated ambient temperature (basic value) at a historical time is less than or equal to the temperature rise limit. If so, use the temperature difference as an increment, and the sum of the basic value and the increment as the estimated ambient temperature at the time of power-on; otherwise, use the temperature rise limit as an increment, and the sum of the basic value and the increment as the estimated ambient temperature at the time of power-on.

[0106] Step S403: When the power is off, monitor the vehicle speed, boost pressure, and engine intake airflow to obtain the monitoring results.

[0107] Step S404: Based on the monitoring results of step S403, determine whether the signals of the turbocharger temperature sensor and the intake air temperature sensor are both valid; if yes, proceed to step S405; otherwise, proceed to step S406.

[0108] Step S405: Take the minimum value between the turbocharger temperature sensor data and the intake air temperature sensor data at the non-power-on time as the estimated ambient temperature value at the non-power-on time. Proceed to step S407.

[0109] Step S406: Take the minimum value among the turbocharger temperature sensor data at the non-power-on time, the intake air temperature sensor data at the non-power-on time, and the estimated ambient temperature at historical times, as the estimated ambient temperature at the non-power-on time. Execute step S407.

[0110] Step S407: Perform temperature filtering on the estimated ambient temperature values ​​at different times to obtain the target ambient temperature value.

[0111] The steps S401 to S407 described above can estimate the ambient temperature based on the intake air temperature sensor and the turbocharger temperature sensor on the engine intake path, thereby ensuring the input of ambient temperature information for the hybrid power system even if the ambient temperature sensor fails.

[0112] This embodiment also provides a vehicle including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0113] Optionally, the vehicle may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0114] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0115] S1, when the vehicle is detected to be powered on and the vehicle's ambient temperature sensor is malfunctioning, detect whether the signals of the vehicle's engine intake air temperature sensor and turbocharger temperature sensor are valid after the power-on moment.

[0116] S2, if the signals of the engine intake temperature sensor and the turbocharger temperature sensor are both valid after the power-on time, then the estimated value of the ambient temperature of the vehicle after the power-on time is determined based on the sensor data of the intake temperature sensor and the turbocharger temperature sensor.

[0117] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0118] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0119] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0120] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0121] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0122] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for estimating ambient temperature, characterized in that, For hybrid vehicles, the method includes: If the vehicle is detected to be powered on and the ambient temperature sensor of the vehicle is malfunctioning, the system checks whether the signals of the engine intake air temperature sensor and the turbocharger temperature sensor of the vehicle are valid after the power-on time. If the signals from the engine intake temperature sensor and the turbocharger temperature sensor of the vehicle are both valid after the power-on time, then the estimated ambient temperature of the vehicle after the power-on time is determined based on the sensor data of the intake temperature sensor and the turbocharger temperature sensor.

2. The environmental temperature estimation method according to claim 1, characterized in that, Based on the sensor data from the intake air temperature sensor and the turbocharger temperature sensor, determine the estimated ambient temperature of the vehicle after power-on, including: The minimum value between the sensor data of the intake air temperature sensor and the sensor data of the turbocharger temperature sensor at the non-power-on time will be used as the estimated value of the ambient temperature at the non-power-on time; the non-power-on time is the time when the vehicle is in operation after the power-on time.

3. The environmental temperature estimation method according to claim 1, characterized in that, After the power-on time, if the signal of the intake air temperature sensor is invalid, and / or if the signal of the turbocharger temperature sensor is invalid, the method further includes: Obtain the pre-stored historical temperature estimates; The minimum value among the intake air temperature sensor data at the non-power-on time, the turbocharger temperature sensor data at the non-power-on time, and the estimated ambient temperature at the historical time is determined as the estimated ambient temperature at the non-power-on time.

4. The environmental temperature estimation method according to claim 1, characterized in that, The method further includes: When the vehicle is detected to be powered on and the ambient temperature sensor fails, the sensor data of the intake air temperature sensor at the time of power-on, the sensor data of the turbocharger temperature sensor at the time of power-on, and the pre-stored estimated values ​​of the ambient temperature at historical times are acquired. The minimum value between the intake air temperature sensor data at the power-on moment and the turbocharger temperature sensor data at the power-on moment is used as the comparison value; the estimated ambient temperature value at the historical moment is used as the basic value. Furthermore, a temperature rise limit is determined; the temperature rise limit represents the allowable temperature rise between the power-on time and the historical time under different downtime of the vehicle. Determine whether the temperature difference between the value to be compared and the baseline value is less than or equal to the temperature rise limit; if so, use the temperature difference as an increment. The sum of the basic value and the incremental value is used as the estimated ambient temperature at the time of power-on.

5. The environmental temperature estimation method according to claim 4, characterized in that, The method further includes: When the temperature difference is greater than the temperature rise limit, the temperature rise limit is taken as an increment. The sum of the basic value and the incremental value is used as the estimated ambient temperature at the time of power-on.

6. The environmental temperature estimation method according to claim 4, characterized in that, Determine the temperature rise limit, including: Obtain the downtime of the vehicle; Based on the vehicle's downtime, a temperature rise limit corresponding to the vehicle's downtime is determined from a preset mapping relationship between different downtimes and different temperature rise limits; the temperature rise limit in the mapping relationship increases as the downtime increases.

7. The environmental temperature estimation method according to claim 1, characterized in that, Detecting whether the signal from the engine intake air temperature sensor of the vehicle is valid after power-on includes: When the intake air flow rate of the engine is less than a preset low flow rate threshold, the signal of the intake air temperature sensor is determined to be invalid. When the cumulative intake airflow of the engine within a preset time period is less than a preset cumulative threshold, the signal of the intake air temperature sensor is determined to be invalid; the cumulative threshold represents the intake airflow required to cool the intake air temperature sensor.

8. The environmental temperature estimation method according to claim 1, characterized in that, Determining whether the signal from the turbocharger temperature sensor of the vehicle's engine is valid after power-on includes: When the vehicle speed is greater than a preset first speed threshold and less than or equal to a preset second speed threshold, and the turbocharger outlet pressure is within a preset first pressure range, the signal of the turbocharger temperature sensor is determined to be valid; the first pressure range represents the turbocharger outlet pressure range when the engine is under low load; the first speed threshold is less than the second speed threshold; the first speed threshold represents the minimum speed value for the vehicle to transition from a stationary state to a moving state; the second speed threshold represents the minimum speed value for the vehicle to enter a driving state. When the vehicle speed is greater than the second speed threshold and the turbocharger outlet pressure is within a preset second pressure range, the signal of the turbocharger temperature sensor is determined to be valid; the value within the second pressure range is greater than the value within the first pressure range; the second pressure range characterizes the turbocharger outlet pressure range when the engine is under high load.

9. The method for estimating ambient temperature according to any one of claims 1 to 8, characterized in that, The method further includes: The estimated ambient temperature is filtered to obtain the target ambient temperature value after the vehicle is powered on and running.

10. A vehicle, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the ambient temperature estimation method according to any one of claims 1 to 9.

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