Method and system for monitoring abnormal torque of pure electric vehicle

Abstract

The invention discloses a pure electric vehicle torque abnormity monitoring method and system, and the method comprises the steps: obtaining vehicle parameters in real time, determining a vehicle driving mode, determining a required torque according to the vehicle parameters and the driving mode, and determining a redundant torque according to the vehicle parameters in a vehicle driving process; and performing torque abnormity monitoring based on the demand torque and the redundant torque, and determining a final request torque. Different cores in the controller are used for calculating the required torque and the redundant torque respectively, torque abnormity monitoring is carried out, power output can be interrupted in the fault state that the calculated torque is too large abnormally, and the risk caused by further unexpected acceleration of the vehicle is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular relates to a method and system for monitoring torque abnormality of a pure electric vehicle. Background Art

[0002] The most important function of a pure electric vehicle controller is to calculate the torque required by the motor through the driver's operation of the pedals or the channel requirements of the intelligent driving system. The correct calculation of the torque is of great significance to driving safety.

[0003] At present, torque anomaly monitoring generally involves the controller using the maximum allowable torque as the monitoring threshold for torque anomalies for anomaly monitoring. However, when the controller experiences random hardware failure or a systemic failure caused by a design error due to human factors, there is a high probability that the requested torque value calculated by the controller will deviate, resulting in monitoring failure. If the deviation results in a request for excessive torque, the vehicle may experience unexpected acceleration in some driving scenarios, which is extremely dangerous in some driving scenarios and seriously threatens driving safety. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a method and system for monitoring torque abnormality of a pure electric vehicle.

[0005] The technical solution adopted by the present invention is: a method for monitoring torque abnormality of a pure electric vehicle, during the vehicle driving process, the vehicle parameters are obtained in real time, the driving mode of the vehicle is determined, the required torque is determined according to the vehicle parameters and the driving mode, the redundant torque is determined according to the vehicle parameters, the torque abnormality is monitored based on the required torque and the redundant torque, and the final requested torque is determined.

[0006] Further, determining the required torque includes: determining a first driving torque by searching a torque map table under the driving mode based on vehicle parameters, and using the first driving torque as the required torque.

[0007] Furthermore, determining the required torque also includes: determining a first intelligent driving torque in the driving mode based on vehicle parameters, and taking a larger value between the first driving torque and the first intelligent driving torque as the required torque.

[0008] Furthermore, determining the required torque also includes: determining a correction torque according to a current vehicle speed, and the final required torque is the sum of the required torque before correction and the correction torque.

[0009] Further, determining the correction torque according to the current vehicle speed includes: searching the target acceleration map table according to the current vehicle speed to obtain the acceleration target value, and the correction torque is: correction torque = K*(acceleration target value - current acceleration), K is the torque correction coefficient.

[0010] Further, the demand torque at the current moment is limited according to the first set torque change slope and the demand torque at the previous moment to obtain the demand limit torque at the current moment, and the torque abnormality monitoring is performed based on the demand limit torque at the current moment.

[0011] Further, determining the redundant torque includes: searching a torque map table in a sport mode based on vehicle parameters to determine a second driving torque, and using the second driving torque as the redundant torque.

[0012] Furthermore, determining the redundant torque also includes: determining a second intelligent driving torque in the sport mode based on vehicle parameters, and taking a larger value between the second driving torque and the second intelligent driving torque as the redundant torque.

[0013] Further, the redundant torque at the current moment is limited according to the second set torque change slope and the redundant torque at the previous moment to obtain the redundant limited torque at the current moment, and the torque abnormality monitoring is performed based on the redundant limited torque at the current moment.

[0014] Furthermore, the abnormality monitoring of torque according to the required torque and the redundant torque and determining the final requested torque includes:

[0015] Calculate the difference between the required torque and the redundant torque. If the difference is greater than the set threshold, the required torque calculation is judged to be abnormal and the abnormal time is monitored; otherwise, the required torque is used as the final requested torque;

[0016] If the abnormal time is greater than the set time, the final requested torque is determined to be 0;

[0017] If the abnormal time is less than the set time, the redundant torque is used as the final requested torque.

[0018] A pure electric vehicle torque abnormality monitoring system, comprising:

[0019] Parameter acquisition module, used to obtain vehicle parameters in real time,

[0020] A mode determination module, for determining a driving mode of a vehicle;

[0021] Common core, used to determine the required torque based on vehicle parameters and driving mode,

[0022] The safety core is used to determine the redundant torque according to the vehicle parameters, compare the required torque with the redundant torque, monitor the torque abnormality according to the comparison result, and determine the final requested torque.

[0023] The beneficial effects of the present invention are:

[0024] The present invention calculates the required torque and the redundant torque respectively through different cores in the controller, and performs torque abnormality monitoring. In the event of a fault state in which the calculated torque is abnormally excessive, the power output can be interrupted to avoid the risk of further unexpected acceleration of the vehicle.

[0025] When the vehicle does not have an intelligent driving system, the present invention uses the driving torque operated by the driver as the required torque and the redundant torque. When the vehicle has an intelligent driving system, the driving torque and the intelligent driving torque are coordinated, and the larger value thereof is used as the required torque and the redundant torque.

[0026] The present invention limits the demand torque and redundant torque at the current moment by setting the torque change slope, thereby ensuring a smooth transition of the torque request and avoiding vehicle shaking or impact caused by torque mutation to the driver and passengers.

[0027] The present invention corrects and adjusts the required torque based on the current vehicle speed, thereby avoiding safety hazards caused by continuous request for larger torque, which causes the maximum speed of the vehicle to exceed the speed limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a flow chart of the method of the present invention.

[0029] Figure 2 It is a schematic representation of the torque map under different accelerator pedal openings and different actual motor speeds of the present invention.

[0030] Figure 3 It is a schematic diagram of limiting the required torque and redundant torque based on the torque change slope of the present invention.

[0031] Figure 4 It is a system principle diagram of the present invention. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides a method for monitoring torque abnormality of a pure electric vehicle, comprising the following steps:

[0035] Step 1: During the driving process of the vehicle, the vehicle parameters are obtained in real time to determine the driving mode of the vehicle;

[0036] Step 2, determining the required torque according to vehicle parameters and driving mode;

[0037] Step 3, determining redundant torque according to vehicle parameters;

[0038] Step 4: perform torque abnormality monitoring based on the required torque and the redundant torque, and determine the final requested torque.

[0039] The present invention calculates the required torque and the redundant torque respectively through different calculation methods, and performs torque abnormality monitoring. In the event of a fault state in which the calculated torque is abnormally excessive, the power output can be interrupted to avoid the risk of further unexpected acceleration of the vehicle.

[0040] It can be understood that the vehicle parameters in the above step 1 include the accelerator pedal opening, the current actual speed, the current vehicle speed, etc., but are not limited to these parameters. In actual situations, other parameters that are needed may also be included, such as the position information, environmental information, and vehicle information (such as transmission ratio, tire rolling radius, etc.) required for the intelligent driving system to calculate the torque. The vehicle parameters are obtained through the parameters of the vehicle itself and sensors and / or detection equipment arranged in various parts of the vehicle. After the corresponding parameters are detected, they are transmitted to the common core and safety core of the vehicle controller to calculate the required torque and redundant torque.

[0041] It should be noted that the driving mode of the vehicle in step 1 includes a normal mode and a sports mode. The vehicle is provided with a hardware switch or button for switching the driving mode, or an electronic switch for selecting the driving mode is provided on the central control screen. The driving mode is determined by the driver's operation of the corresponding switch. When the driver presses the switch button corresponding to the driving mode, different switch signals correspond to different driving modes, and the normal core calculates the required torque based on the driving mode.

[0042] It can be understood that the calculation of the required torque in step 2 is implemented by a common core in the vehicle controller, and the calculation process is:

[0043] First, determine the driving mode. The torque value required by the driver in different driving modes is different. Compared with the normal mode, the torque value required by the driver in the sports mode will be larger to achieve more abundant power output. The torque value required by the driver in the normal mode will be smaller to achieve lower power consumption and longer cruising range.

[0044] In the driving mode, the required torque is calculated according to the obtained vehicle parameters, specifically, the first driving drive torque is determined according to the torque map table in the corresponding driving mode, and the torque map table in the corresponding driving mode includes the torque map table in the normal driving mode and the torque map table in the sports driving mode. That is, if the current driving mode is the normal driving mode, the first driving drive torque is determined by searching the torque map table in the normal driving mode based on the current accelerator pedal opening and the actual speed; if the current driving mode is the sports driving mode, the first driving drive torque is determined by searching the torque map table in the sports driving mode based on the current accelerator pedal opening and the actual speed. The first driving drive torque is the driving torque required by the driver. An example of a torque map table under different accelerator pedal openings and different actual motor speeds is as follows: Figure 2 shown.

[0045] In applications, most vehicles are currently equipped with intelligent driving systems with functions such as assisted driving and automatic parking. Therefore, when a vehicle is equipped with an intelligent driving system, the intelligent driving system will also calculate the corresponding first intelligent driving torque (i.e., the driving torque required by the intelligent driving system) based on vehicle parameters and driving mode. At this time, when calculating the required torque, the vehicle controller will coordinate the two required torques, that is, take the larger value of the first driving torque and the first intelligent driving torque as the required torque.

[0046] The process of calculating the intelligent driving torque by the intelligent driving system generally includes the steps of setting the target driving path, calculating the current target torque, and adjusting the torque value. The target driving path is to plan a reasonable driving path based on the user's location information, the vehicle's current location and the surrounding environment information; the current target torque is to calculate the current torque value that needs to be output based on the vehicle's driving mode, current driving data (such as vehicle speed, acceleration, etc.), vehicle information (such as transmission ratio, tire rolling radius, etc.), etc.; the torque value is to adjust the calculated torque value based on real-time updates of environmental changes and driver's intentions. For example, when an obstacle is detected ahead, the system may need to reduce the torque to reduce the vehicle speed; when the driver wants to accelerate, the system needs to increase the torque to provide sufficient power.

[0047] In application, if the vehicle is not equipped with a corresponding intelligent driving system, the driving torque required by the driver (the first driving torque) is directly used as the required torque.

[0048] In some embodiments, in some special cases (such as when the current vehicle speed is greater than the set vehicle speed), the required torque needs to be corrected and adjusted, and the torque output is limited according to the current vehicle speed and the calibrated target acceleration map to avoid continuing to request a larger torque and causing the vehicle's maximum speed to exceed the speed limit. Specifically, the correction torque is determined according to the vehicle's current speed, and the final required torque is the sum of the required torque before correction and the correction torque.

[0049] Determining the correction torque according to the current vehicle speed includes: searching the target acceleration map table according to the current vehicle speed to obtain the acceleration target value, and the correction torque is: correction torque = K*(acceleration target value-current acceleration), K is the torque correction coefficient. One of the target acceleration map tables and torque correction coefficients are shown in Table 1 and Table 2, respectively. When searching the corresponding map table, if the vehicle speed is between two critical values ​​in the table, the corresponding acceleration target value and torque correction coefficient are determined by taking the value downward of the vehicle speed. For example, if the current vehicle speed is 153km / h, the acceleration target value is 1.5, which corresponds to the acceleration target value when the vehicle speed is 152km / h, and the torque correction coefficient is 5, which corresponds to the torque correction coefficient when the vehicle speed is 150km / h.

[0050] Table 1 Target acceleration map

[0051] Target acceleration Map

[0052] Vehicle speed (km / h) 148 150 152 154 156 158 160 162 164 166 168 170 172 Acceleration target value (m / s2) 2.3 1.8 1.5 0.9 0.6 0.3 0 -0.4 -0.7 -0.9 -1.1 -1.3 -1.6

[0053] Table 2 Torque correction coefficient table

[0054] Torque correction factor Map

[0055] Vehicle speed (km / h) 0 50 100 150 155 160 165 200 Torque correction factor 5 5 5 5 3 2 3 5

[0056] The acceleration target value is generally smaller than the current acceleration of the vehicle. According to the data in Table 1 and Table 2 and the above-mentioned correction torque formula, the correction torque is generally a negative value. The greater the current vehicle speed, the greater the absolute value of the correction torque, and the smaller the final required torque after correction. This torque correction method can ensure that the torque output can be appropriately reduced when driving at high speed to prevent the vehicle from losing control due to excessive power.

[0057] It can be understood that the calculation of redundant torque is realized by the safety core in the vehicle controller, and the process is:

[0058] In order to ensure that the driving torque of the safety core is greater than or equal to the driving torque of the normal core when the vehicle is driving, the calculation of the redundant torque does not take into account the current driving mode, but is directly determined according to the vehicle parameters and the torque map table in the sports driving mode, that is, the second driving torque is determined by searching the torque map table in the sports driving mode based on the current accelerator pedal opening and the actual speed. The second driving torque is the driving torque required by the driver. That is, under normal circumstances (no vehicle controller software or hardware failure), if the current driving mode is the normal mode, the second driving torque is greater than the first driving torque; if the current driving mode is the sports mode, the second driving torque is equal to the first driving torque.

[0059] When calculating redundant torque, when the vehicle is equipped with an intelligent driving system, the driving torque required by the intelligent driving system must also be considered. That is, for vehicles with intelligent driving systems, the intelligent driving system will calculate the second intelligent driving torque in the sports mode based on the vehicle parameters, and then take the larger value of the second driving torque and the second intelligent driving torque as the redundant torque. When the vehicle is not equipped with a corresponding intelligent driving system, the driving torque required by the driver (the second driving torque) is directly used as the redundant torque.

[0060] The solution of coordinating the driving torque required by the driver and the driving torque required by the intelligent driving system when calculating the required torque and the redundant torque has the following advantages:

[0061] 1. Ensure that power requirements are met: By selecting a larger torque value, the vehicle can be guaranteed to have enough power to cope with various driving scenarios. Whether the driver wants to accelerate quickly or the intelligent driving system determines that more torque is needed to ensure safety or efficiency, this strategy can ensure sufficient power output.

[0062] 2. Improve driving safety: Intelligent driving systems often have more comprehensive road condition perception and prediction capabilities than drivers. In some emergency situations, intelligent driving systems may need greater torque to avoid collisions or maintain stability. In this case, choosing a larger torque value will help improve the safety performance of the vehicle.

[0063] 3. Optimize driving experience: The driver has a direct feeling of the vehicle's power response. If the intelligent driving system can provide more torque when needed, the driver will feel a smoother and more sensitive acceleration experience during driving. This helps to improve the driver's trust and satisfaction with the intelligent driving system.

[0064] It should be noted that the torque abnormality monitoring is performed according to the final required torque and the redundant torque determined above, and the final requested torque is determined, including the following steps:

[0065] Step 1: Calculate the difference between the required torque and the redundant torque, that is, the required torque minus the redundant torque. If the difference is greater than the set threshold, it is determined that the required torque calculation is abnormal, monitor the abnormal time, and proceed to step 2 or step 3; if the difference is less than or equal to the set threshold, it means that there is no abnormality in the required torque calculation, and then proceed to step 4. Since the required torque is generally less than or equal to the redundant torque, or slightly greater than the redundant torque, the difference between the required torque and the redundant torque is generally a negative value or 0 or a small positive value. Therefore, the set threshold is preferably 0Nm or 10Nm, 20Nm, 30Nm, 40Nm. When the difference is greater than the set threshold, it means that the required torque calculation is abnormal.

[0066] Step 2: If the abnormal time is greater than the set time, that is, the calculated demand torque is greater than the redundant torque for the continuous set time, it means that the calculation of the common core torque fails. At this time, the output is directly interrupted, that is, the final requested torque is determined to be 0 to avoid safety hazards. While interrupting the output, a prompt instruction to light up the fault is sent to the instrument to inform the driver that the vehicle has a fault and thus interrupted the power output. The set time is generally an integer multiple of the torque calculation cycle (the time interval for the vehicle controller to calculate the demand torque and the redundant torque), and in this embodiment, it is preferably 0.5s or 1s.

[0067] Step three, if the abnormal time is less than or equal to the set time, that is, before the required torque calculation is abnormal and the duration does not reach the set time, in order to ensure driving safety, a smaller torque value is output, that is, the redundant torque calculated by the safety core is sent to the motor as the final requested torque.

[0068] Step 4: When there is no abnormality in the calculation of the required torque, the required torque is directly used as the final requested torque.

[0069] In some embodiments, in order to prevent the vehicle from shaking or impacting due to sudden torque changes, which may cause a bad experience for the driver and passengers, it is necessary to limit the torque to ensure the smoothness of the driver's driving when increasing or decreasing the torque of the vehicle. Specifically, the torque is limited by calibrating the torque change slope.

[0070] For the required torque, the first set torque change slope k1 is calibrated, and the required torque T at the previous moment is calculated based on the first set torque change slope k1 and the required torque T at the previous moment. 1a The torque required at the current moment is T 2a Limit the torque T required at the current moment a , based on the demand limit torque at the current moment to monitor the torque abnormality.

[0071] It can be understood that limiting the required torque at the current moment to obtain the required limited torque at the current moment includes:

[0072] If the current demand torque is positive, and the demand torque T calculated at the current moment 2a Greater than the required torque T at the previous moment 1a , and T 2a -T 1a >k1 / T, k1>0, then T a =T 1a +k1 / T, T is the calculation period of torque.

[0073] If the current demand torque is positive, and the demand torque T calculated at the current moment 2a Less than the required torque T at the previous moment 1a , and T 1a -T 2a>k1 / T, k1>0, then T a =T 1a -k1 / T.

[0074] If the current demand torque is positive, and the demand torque T calculated at the current moment 2a The required torque T at the previous moment 1a Satisfy|T 2a -T 1a |≤k1 / T, k1>0, then T a =T 2a .

[0075] If the current demand torque is negative, and the demand torque T calculated at the current moment 2a The absolute value is greater than the required torque T at the previous moment 1a Absolute value, and T 2a -T 1a <k1 / T, k1<0, then T a =T 1a +k1 / T.

[0076] If the current demand torque is negative, and the demand torque T calculated at the current moment 2a The absolute value is less than the required torque T at the previous moment 1a Absolute value, T 1a -T 2a <k1 / T, k1<0, then T a =T 1a -k1 / T.

[0077] If the current demand torque is negative, and the demand torque T calculated at the current moment 2a The required torque T at the previous moment 1a Satisfy|T 2a -T 1a |≤|k1 / T|, k1<0, then T a =T 2a .

[0078] For example, if the current required torque is positive, and the required torque T calculated at the current moment is 2a T than the required torque T at the previous moment 1a If the load is 50Nm, and k1 / T is 20Nm, then T a =T 1a +20Nm.

[0079] It should be noted that the first set torque change slope k1 is a calibrated value, and the k1 values ​​corresponding to different torques are different. The k1 value is determined by looking up a calibrated required torque-torque change slope map table.

[0080] For the redundant torque, the second set torque change slope k2 is calibrated, and the second set torque change slope k2 and the redundant torque T at the previous moment are calculated. 1b The redundant torque T at the current moment 2b Limit the redundant limit torque T at the current moment b , torque abnormality monitoring is performed based on the redundant limit torque at the current moment.

[0081] If the current redundant torque is positive, and the redundant torque T calculated at the current moment 2b Greater than the redundant torque T at the previous moment 1b , and T 2b -T 1b >k2 / T, k2>0, then T b =T 1b +k2 / T.

[0082] If the current redundant torque is positive, and the redundant torque T calculated at the current moment 2b Less than the redundant torque T at the previous moment 1b , and T 1b -T 2b >k2 / T, k2>0, then T b =T 1b -k2 / T.

[0083] If the current redundant torque is positive, and the redundant torque T calculated at the current moment 2b The redundant torque T at the previous moment 1b Satisfy|T 2b -T 1b |≤k2 / T, k2>0, then T b =T 2b .

[0084] If the current redundant torque is negative, and the redundant torque T calculated at the current moment 2b The absolute value is greater than the redundant torque T at the previous moment 1b Absolute value, and T 2b -T 1b <k2 / T, k2<0, then T b =T 1b +k2 / T.

[0085] If the current redundant torque is negative, and the redundant torque T calculated at the current moment 2b The absolute value is less than the redundant torque T at the previous moment 1b Absolute value, and T 1b -T 2b <k2 / T, k2<0, then T b =T 1b -k2 / T.

[0086] If the current redundant torque is negative, and the redundant torque T calculated at the current moment 2b The redundant torque T at the previous moment 1b Satisfy|T 2b -T 1b |≤|k2 / T|, k2<0, then T b =T 2b .

[0087] It should be noted that the second set torque change slope k2 is a calibrated value, and the k2 values ​​corresponding to different torques are different. The k2 value is determined by looking up a calibrated redundant torque-torque change slope map table.

[0088] In some embodiments, the torque change slope is the speed at which the torque rises or falls. The increase and decrease of the required torque in the ordinary core is limited by a certain slope to ensure that its change is not large, thereby avoiding complaints from passengers; if the redundant torque in the safety core changes too slowly or too quickly, it will cause the torque monitoring abnormality to be falsely detected.

[0089] Therefore, under normal circumstances, to ensure that the redundant torque calculated by the safety core is greater than or equal to the demand calculated by the ordinary core (regardless of positive or negative torque), it is necessary to limit the rising and falling slopes of the torque (demand torque and redundant torque) respectively to ensure that the redundant torque of the safety core completely covers the demand torque in the ordinary core, such as Figure 3 As shown, in order to achieve this purpose, it is necessary to limit the magnitudes of the first set torque change slope k1 and the second set torque change slope k2, specifically:

[0090] The torque rising process of positive torque, that is, the demand torque and redundant torque at the current moment are both greater than the demand torque and redundant torque at the previous moment, k2=k1*1.2, k1>0, k2>0;

[0091] The decreasing process of positive torque, that is, the demand torque and redundant torque at the current moment are both less than the demand torque and redundant torque at the previous moment, k2=k1*0.8, k1>0, k2>0;

[0092] The absolute value increase process of the negative torque (i.e., the negative torque decrease process in FIG3 ), that is, the absolute values ​​of the demand torque and the redundant torque at the current moment are greater than the absolute values ​​of the demand torque and the redundant torque at the previous moment, k2=k1*1.2, k1<0, k2<0;

[0093] The absolute value of the negative torque decreases (i.e. Figure 3 The negative torque rising process in the process), that is, the absolute values ​​of the demand torque and the redundant torque at the current moment are both smaller than the absolute values ​​of the demand torque and the redundant torque at the previous moment, k2=k1*0.8, k1<0, k2<0.

[0094] In some embodiments, performing torque abnormality monitoring according to the determined demand limit torque and redundant limit torque and determining the final request torque includes the following steps:

[0095] Step 1: Calculate the difference between the demand limit torque and the redundant limit torque, that is, the demand limit torque minus the redundant limit torque. If the difference is greater than the set threshold, it is determined that the demand limit torque calculation is abnormal, monitor the abnormal time, and proceed to step 2 or step 3; if the difference is less than or equal to the set threshold, it means that there is no abnormality in the demand limit torque calculation, and proceed to step 4.

[0096] Step 2: If the abnormal time is greater than the set time, that is, the calculated demand limit torque is greater than the redundant limit torque within the set time, it means that the calculation of the common core torque fails. At this time, the output is directly interrupted, that is, the final request torque is determined to be 0 to avoid safety hazards. At the same time as the output is interrupted, a fault prompt instruction is sent to the instrument to inform the driver that the vehicle has a fault and the power output is interrupted.

[0097] Step three, if the abnormal time is less than or equal to the set time, that is, before the demand limit torque calculation is abnormal and the duration does not reach the set time, in order to ensure driving safety, a smaller torque value is output, that is, the redundant limit torque calculated by the safety core is sent to the motor as the final request torque.

[0098] Step 4: When there is no abnormality in the calculation of the demand limit torque, the demand limit torque is directly used as the final requested torque.

[0099] Example 2

[0100] The vehicle controller receives a series of parameters of the driver's vehicle operation and converts them into the torque required by the driver; then coordinates the torque required by the driver and the torque required by the intelligent driving system; and adjusts the torque within a limited range based on the vehicle status. Finally, it outputs a suitable and stable torque request and sends it to the drive motor through the CAN bus to request the execution of this torque.

[0101] The complex torque calculation process in the vehicle controller may cause deviations in the final calculated torque request value if any link fails or is executed incorrectly. When the torque request is greater than the normal value and exceeds a certain threshold due to the deviation, the motor may execute unexpected excessive torque, causing the vehicle to accelerate unexpectedly, which is extremely dangerous in some driving scenarios and seriously threatens driving safety.

[0102] In order to reduce the risk of unexpected vehicle acceleration caused by excessive torque calculated by the vehicle controller, the present invention selects a multi-core vehicle controller for torque control. The multi-core controller is divided into a common core and a safety core. For this purpose, this embodiment provides a pure electric vehicle torque abnormality monitoring system, such as Figure 4Shown, including

[0103] Parameter acquisition module, used to obtain vehicle parameters,

[0104] A mode determination module, for determining a driving mode of a vehicle;

[0105] Common core, used to determine the required torque based on vehicle parameters and driving mode,

[0106] The safety core is used to determine the redundant torque according to the vehicle parameters and driving mode, compare the required torque with the redundant torque, monitor the torque abnormality according to the comparison result, and determine the final requested torque.

[0107] Among them, the common core and the safety core are both integrated in the vehicle controller. The common core has a large space and is used for fine logic calculations, while the safety core has a small space and is used for partial safety logic calculations and monitoring. The torque is accurately calculated in the common core of the controller, and the torque calculation process is redundantly calculated and abnormally monitored in the safety core to confirm that the calculated torque of the common core is a safe value. When the safety core detects that the demand torque calculated in the common core is greater than the redundant torque calculated in the safety core by a certain threshold and maintains for a certain period of time, it is determined that the demand torque calculation is abnormal. The vehicle controller will send the torque request output to the motor as 0, cut off the output of the driving force, and send a fault prompt instruction to the instrument to inform the driver that the vehicle has a fault and thus interrupted the power output. Compared with the common core, the safety core adopts functional safety design in hardware and underlying software, with higher safety and reliability. The common core calculates the demand torque, the safety core calculates the redundant torque, and then compares the two to monitor the abnormality of the demand torque calculation, which can effectively avoid the situation where the final request torque is too large and the vehicle accelerates unexpectedly, thereby ensuring driving safety.

[0108] It can be understood that the above-mentioned vehicle parameters include the accelerator pedal opening, the current actual speed, the current vehicle speed, etc., but are not limited to these parameters. In actual situations, other parameters that are needed may also be included, such as the position information, environmental information, vehicle information (such as transmission ratio, tire rolling radius, etc.) required for the intelligent driving system to calculate the torque. The vehicle parameters are obtained through the parameters of the vehicle itself and sensors and / or detection equipment arranged in various parts of the vehicle. After the corresponding parameters are detected, they are transmitted to the ordinary core and safety core of the vehicle controller to calculate the required torque and redundant torque.

[0109] It should be noted that the vehicle's driving modes include normal mode and sports mode. The vehicle is equipped with a hardware switch or button for switching the driving mode, or an electronic switch for selecting the driving mode is set on the central control screen. The driving mode is determined by the driver's operation of the corresponding switch. When the driver presses the switch button corresponding to the driving mode, the switch signal of the corresponding driving mode will be transmitted to the common core of the vehicle controller. Different switch signals correspond to different driving modes. The common core calculates the required torque based on the driving mode.

[0110] It can be understood that the process of calculating the required torque in the ordinary core is the same as the calculation method of the required torque in the above-mentioned embodiment 1, and the process of calculating the redundant torque in the safety core is the same as the calculation method of the redundant torque in the above-mentioned embodiment 1, and will not be described in detail here.

[0111] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0112] In order to make the description of the present disclosure more detailed and complete, the above description is provided for the implementation and specific embodiments of the present invention; however, this is not the only form of implementing or using the specific embodiments of the present invention. The implementation covers the features of multiple specific embodiments and the method steps and sequences used to construct and operate these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and step sequences.

[0113] Those skilled in the art may also understand that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention may be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly demonstrate the interchangeability of hardware and software, the various illustrative components, units, and steps described above have generally described their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present invention.

[0114] The various illustrative logic blocks or units described in the embodiments of the present invention can be implemented or operated by a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination of the above. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0115] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field.

Claims

1. A method for monitoring abnormal torque of a pure electric vehicle, characterized in that: During vehicle driving, vehicle parameters are acquired in real time to determine the vehicle's driving mode. The required torque is determined based on the vehicle parameters and the driving mode. The redundant torque is determined based on the vehicle parameters. Torque abnormalities are monitored based on the required torque and the redundant torque, and the final requested torque is determined.

2. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: Determining the required torque includes: determining a first driving torque by looking up a torque map table in the driving mode based on vehicle parameters, and using the first driving torque as the required torque.

3. The method for monitoring abnormal torque of a pure electric vehicle according to claim 2, characterized in that: Determining the required torque also includes: determining a first intelligent driving torque in the driving mode based on vehicle parameters, and taking a larger value between the first driving torque and the first intelligent driving torque as the required torque.

4. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: Determining the required torque also includes: determining a correction torque according to the current vehicle speed, and the final required torque is the sum of the required torque before correction and the correction torque.

5. The method for monitoring abnormal torque of a pure electric vehicle according to claim 4, characterized in that: Determining the correction torque according to the current vehicle speed includes: searching the target acceleration map table according to the current vehicle speed to obtain the acceleration target value, and the correction torque is: correction torque = K*(acceleration target value - current acceleration), K is the torque correction coefficient.

6. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: The demand torque at the current moment is limited according to the first set torque change slope and the demand torque at the previous moment to obtain the demand limit torque at the current moment, and the torque abnormality monitoring is performed based on the demand limit torque at the current moment.

7. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: Determining the redundant torque includes: searching a torque map table in a sport mode based on vehicle parameters to determine a second driving torque, and using the second driving torque as the redundant torque.

8. The method for monitoring abnormal torque of a pure electric vehicle according to claim 7, characterized in that: Determining the redundant torque also includes: determining a second intelligent driving torque in the sport mode based on vehicle parameters, and taking a larger value between the second driving torque and the second intelligent driving torque as the redundant torque.

9. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: The redundant torque at the current moment is limited according to the second set torque change slope and the redundant torque at the previous moment to obtain the redundant limited torque at the current moment, and the torque abnormality monitoring is performed based on the redundant limited torque at the current moment.

10. The method for monitoring abnormal torque of a pure electric vehicle according to claim 1, characterized in that: The abnormality monitoring of torque according to the required torque and the redundant torque and determining the final requested torque includes: Calculate the difference between the required torque and the redundant torque. If the difference is greater than the set threshold, the required torque calculation is judged to be abnormal and the abnormal time is monitored; otherwise, the required torque is used as the final requested torque; If the abnormal time is greater than the set time, the final requested torque is determined to be 0; If the abnormal time is less than the set time, the redundant torque is used as the final requested torque.

11. A pure electric vehicle torque abnormality monitoring system, characterized in that: include Parameter acquisition module, used to obtain vehicle parameters in real time, A mode determination module, for determining a driving mode of a vehicle; Common core, used to determine the required torque based on vehicle parameters and driving mode, The safety core is used to determine the redundant torque according to the vehicle parameters, compare the required torque with the redundant torque, monitor the torque abnormality according to the comparison result, and determine the final requested torque.

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