Intelligent network connection passenger car drive system autonomous power-down control method and system

Abstract

The present disclosure provides a kind of intelligent network connection passenger car drive system autonomous power-down control method and system, the scheme includes: real-time acquisition drive system state;When drive system communication is abnormal, based on the speed of vehicle saved before abnormality one time, and combine wheel speed sensor signal or brake pedal signal, speed estimation is carried out;When the speed estimation result is lower than the preset speed, execute vehicle high voltage power-down operation.

Description

Technical Field

[0001] This disclosure belongs to the field of intelligent connected bus control technology, and in particular relates to a method and system for controlling the abnormal autonomous power-down of an intelligent connected bus drive system. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] In recent years, the development trend of intelligent connected buses has become increasingly apparent, with the drive system being a crucial component for vehicle power. However, communication anomalies in the motor controller frequently occur during vehicle operation, posing serious threats to vehicle safety and reliability. Therefore, vehicle safety control during drive system communication anomalies has become one of the key technologies in current research on intelligent connected buses. Most currently available methods for controlling vehicle power-down during drive system anomalies in intelligent connected buses directly reduce the vehicle's voltage when the motor controller experiences a communication failure with the vehicle. However, directly reducing voltage during high-speed driving can easily cause contactor adhesion, leading to power steering failure and loss of vehicle control, thus reducing overall vehicle safety. Summary of the Invention

[0004] To address the aforementioned issues, this disclosure provides a method and system for autonomously powering down an abnormal drive system in an intelligent connected bus. The solution monitors the real-time status of the drive system through the vehicle controller, and combines wheel speed sensor signals and brake pedal signals. When a communication abnormality occurs in the drive system, the vehicle speed is estimated in real time. Once the vehicle speed is low, the vehicle autonomously powers down, preventing loss of control at high speeds and improving the safety, reliability, and stability of the intelligent connected bus.

[0005] According to a first aspect of the present disclosure, a method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus is provided, comprising:

[0006] Real-time acquisition of driver system status;

[0007] When the drive system communication fails, the vehicle speed is estimated based on the vehicle speed saved at the moment before the failure, combined with wheel speed sensor signals or brake pedal signals.

[0008] When the estimated vehicle speed is lower than the preset vehicle speed, the vehicle high voltage power-off operation is performed.

[0009] Furthermore, the real-time acquisition of the drive system status specifically involves: after the vehicle completes the connection to the high voltage, periodically receiving drive system message life signals, and determining whether the drive system status is abnormal based on the drive system message life signals.

[0010] Furthermore, the method of determining whether the drive system status is abnormal based on the drive system message life signal is as follows: according to a preset period, the drive system message life signal is received periodically, and it is determined whether the current life signal is equal to the life signal at the previous moment. If they are equal, it is determined that the motor CAN signal is lost. When it is determined that the motor CAN signal is lost, a timer is started. If it is determined that the motor CAN signal is lost for a preset period of time, it is determined that the drive system communication is abnormal.

[0011] Furthermore, when the drive system communication is abnormal, the vehicle speed is estimated based on the vehicle speed saved at the moment before the abnormality and combined with the wheel speed sensor signal. Specifically, the wheel speeds of the four wheels of the vehicle are obtained based on the wheel speed sensors; the difference between the vehicle speed and the average wheel speed of the four wheels is calculated; when the difference is not greater than a preset threshold, the average wheel speed of the four wheels is used as a reference value for vehicle speed estimation; when the vehicle speed drops below the preset speed, the vehicle high voltage power-off operation is performed.

[0012] Furthermore, when the difference is greater than a preset threshold, the vehicle speed is estimated based on the vehicle speed saved at the moment before the anomaly and in combination with the brake pedal signal.

[0013] Furthermore, the vehicle speed estimation based on the vehicle speed saved at the moment before the anomaly and combined with the brake pedal signal specifically involves: determining the vehicle deceleration based on the obtained brake pedal opening signal, combined with the pre-determined relationship between the vehicle brake pedal opening and the vehicle braking deceleration, and the pre-determined vehicle coasting deceleration when the vehicle is in a coasting state; estimating the vehicle braking time required when the vehicle speed is lower than the preset vehicle speed based on the vehicle speed saved at the moment before the anomaly and the vehicle deceleration; starting from the moment of the drive system communication anomaly, timing is initiated, and when the duration satisfies the vehicle braking time plus a preset time margin, a high-voltage power-off operation is performed on the vehicle.

[0014] Furthermore, the drive system status includes normal communication between the drive system and the vehicle controller, and abnormal communication between the drive system and the vehicle controller.

[0015] According to a second aspect of the present disclosure, an intelligent connected bus drive system abnormal autonomous power-down control system is provided, comprising:

[0016] A status acquisition unit, which is used to acquire the status of the drive system in real time;

[0017] The vehicle speed estimation unit is used to estimate the vehicle speed based on the vehicle speed saved at the moment before the abnormality when the drive system communication is abnormal, and in combination with the wheel speed sensor signal or brake pedal signal.

[0018] The operating unit is used to perform a high-voltage power-off operation on the vehicle when the estimated vehicle speed is lower than the preset vehicle speed.

[0019] According to a third aspect of the present invention, a computer-readable storage medium is provided having a program stored thereon, which, when executed by a processor, implements the above-described method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus.

[0020] According to a fourth aspect of the present invention, an electronic device is provided, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement an abnormal autonomous power-down control method for a smart connected bus drive system as described above.

[0021] Compared with the prior art, the beneficial effects of this disclosure are:

[0022] (1) The present disclosure proposes a method and system for autonomous power-off control of abnormal drive system of intelligent connected bus. The scheme monitors the real-time status of drive system through vehicle controller, and combines wheel speed sensor signal and brake pedal signal. When the vehicle has abnormal drive system communication, the vehicle speed is estimated in real time. When the vehicle speed is low, the vehicle autonomously lowers the high voltage to avoid loss of control of the vehicle under high speed conditions and improve the safety, reliability and stability of intelligent connected bus.

[0023] (2) The proposed solution effectively solves the problem of autonomously controlling the vehicle to safely operate under high voltage when the intelligent connected bus drive system communication is abnormal, effectively avoiding vehicle loss of control due to abnormal motor communication, and improving the safety and reliability of the vehicle.

[0024] Advantages of this disclosure in additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0025] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure.

[0026] Figure 1 This is a flowchart of an abnormal autonomous power-down control method for a drive system of an intelligent connected bus, as described in an embodiment of this disclosure. Detailed Implementation

[0027] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Where there is no conflict, the embodiments and features described herein can be combined with each other.

[0031] Example 1:

[0032] The purpose of this embodiment is to provide a method for controlling the abnormal autonomous power-down of the drive system of an intelligent connected bus.

[0033] A method for controlling the autonomous power-down of an abnormal drive system in an intelligent connected bus includes:

[0034] Real-time acquisition of driver system status;

[0035] When the drive system communication fails, the vehicle speed is estimated based on the vehicle speed saved at the moment before the failure, combined with wheel speed sensor signals or brake pedal signals.

[0036] When the estimated vehicle speed is lower than the preset vehicle speed, the vehicle high voltage power-off operation is performed.

[0037] In specific implementation, the real-time acquisition of the drive system status specifically involves: after the vehicle completes the connection to the high voltage, periodically receiving drive system message life signals, and determining whether the drive system status is abnormal based on the drive system message life signals.

[0038] In specific implementation, the method of judging whether the state of the drive system is abnormal based on the life signal of the drive system message is as follows: according to a preset period, the life signal of the drive system message is received periodically, and it is judged whether the current life signal is equal to the life signal at the previous moment. If they are equal, it is determined that the motor CAN signal is lost. When it is determined that the motor CAN signal is lost, a timer is started. If it is determined that the motor CAN signal is lost for a preset period of time, it is determined that the drive system communication is abnormal.

[0039] In specific implementation, when the drive system communication is abnormal, the vehicle speed is estimated based on the vehicle speed saved at the moment before the abnormality and combined with the wheel speed sensor signal. Specifically, the wheel speeds of the four wheels of the vehicle are obtained based on the wheel speed sensors; the difference between the vehicle speed and the average wheel speed of the four wheels is calculated; when the difference is not greater than a preset threshold, the average wheel speed of the four wheels of the vehicle is used as a reference value for vehicle speed estimation; when the vehicle speed drops below the preset vehicle speed, the vehicle high voltage power-off operation is performed.

[0040] In practice, when the difference is greater than a preset threshold, the vehicle speed is estimated based on the vehicle speed saved at the moment before the anomaly and in combination with the brake pedal signal.

[0041] In specific implementation, the vehicle speed estimation based on the vehicle speed saved at the moment before the anomaly and combined with the brake pedal signal specifically involves: determining the vehicle deceleration based on the obtained brake pedal opening signal, combined with the pre-determined relationship between the vehicle brake pedal opening and the vehicle braking deceleration, and the pre-determined vehicle coasting deceleration when the vehicle is in a coasting state; estimating the vehicle braking time required when the vehicle speed is lower than the preset vehicle speed based on the vehicle speed saved at the moment before the anomaly and the vehicle deceleration; starting from the moment of the communication anomaly in the drive system, timing is initiated, and when the duration satisfies the vehicle braking time plus a preset time margin, the vehicle high-voltage power-off operation is performed.

[0042] In practice, the drive system status includes normal communication between the drive system and the vehicle controller and abnormal communication between the drive system and the vehicle controller.

[0043] For ease of understanding, the following detailed description of the solution in this embodiment is provided in conjunction with the accompanying drawings:

[0044] like Figure 1 As shown, the vehicle controller monitors the real-time status of the drive system, and combines this with wheel speed sensors and brake pedal signals. When a communication anomaly occurs in the drive system, the controller estimates the vehicle speed in real time, and autonomously lowers the high voltage when the vehicle speed is low. The specific steps are as follows:

[0045] (1) Determining communication anomalies in the drive system

[0046] After the vehicle completes the high-voltage connection, the vehicle controller receives drive system messages via the CAN bus and uses the life signal to determine whether the drive system status is abnormal.

[0047] The vehicle controller receives drive system message life signals every 10 milliseconds. It checks if the current life signal (life) is equal to the previous life signal (life_last). If they are equal (life = life_last), the motor CAN signal is considered lost, and mcu_lost_flag = 1. If the life signal (life) is not equal to the previous life signal (life_last), the motor CAN signal is normal, and mcu_lost_flag = 0. When mcu_lost_flag = 1, the vehicle controller starts timing. If mcu_lost_flag remains 1 for 2 seconds, the drive system communication is considered abnormal, and the vehicle state is set to A. If a life signal change occurs once within 2 seconds, the communication system is considered normal, the vehicle state is set to B, and the timer is reset.

[0048] (2) Calculation of normal driving speed

[0049] If the vehicle controller determines the current vehicle status to be B, meaning the vehicle and drive system are communicating normally, the vehicle controller receives the motor speed value n0 via the CAN signal and simultaneously filters the motor speed value n0. The calculation formula is as follows:

[0050] n = 0.5 * n0 + 0.5 * n_last,

[0051] Where n_last is the filtered rotational speed value from the previous moment, and then the vehicle speed v is calculated by combining the speed ratio and tire radius, using the following formula:

[0052]

[0053] Where i is the speed ratio of the reducer and r is the tire radius.

[0054] (3) Estimation of abnormal vehicle speed in drive system

[0055] If the vehicle controller determines the current vehicle state to be A, indicating a communication error between the vehicle and the drive system, the vehicle controller saves the current vehicle speed as v. Simultaneously, the vehicle controller receives signals from the four wheel speed sensors (left front, left rear, right front, and right rear) via CAN signals to obtain the current wheel speed values ​​v1, v2, v3, and v4 respectively. Then, it calculates the average value v5 of the four wheel speed signals using the following formula:

[0056] If the absolute value of the difference between the average value of the four wheel speeds v5 and the vehicle speed v saved just before the drive system communication failure is within 5 km / h, i.e. |v-v5|≤5km / h, then the road adhesion coefficient of the vehicle is considered to be high and the wheel speed sensor signal is reliable. At this time, the vehicle controller uses the average value of the four wheel speed signals as a reference value to estimate the vehicle speed, i.e. v=v5. If v5 drops to below 3 km / h, i.e. v<3km / h, the vehicle controller determines that the vehicle is currently in a low-speed driving stage and performs a vehicle power-off operation.

[0057] If the absolute value of the difference between the calculated average of the four wheel speeds v5 and the vehicle speed v saved just before the drive system communication failure is greater than 5 km / h (i.e., |v-v5|>5 km / h), then it is considered that the road adhesion coefficient of the vehicle is low or the wheel speed sensor signal is abnormal. In this case, the vehicle controller determines that the current wheel speed value is invalid and the vehicle speed cannot be estimated using the wheel speed. In this scenario, the brake pedal opening P needs to be used. brake Estimating vehicle speed based on the overall vehicle weight;

[0058] If the brake pedal opening is P brake Greater than 80%, i.e., P brake If the braking deceleration is greater than 80%, then the vehicle braking deceleration is set to a = -3.5 m / s².2 ;

[0059] If the brake pedal opening is P brake Greater than 50% and less than 80%, i.e., 50% <P brake If the braking deceleration is ≤80%, then the vehicle braking deceleration is set to a = -2.5 m / s². 2 ;

[0060] If the brake pedal opening is P brake Greater than 30% and less than 50%, i.e., 30%. <P brake If the braking deceleration is ≤50%, then the vehicle braking deceleration is set to a = -1.5 m / s². 2 ;

[0061] If the brake pedal opening is P brake Greater than 5% and less than 30%, i.e., 5% <P brake If the braking deceleration is ≤30%, then the vehicle braking deceleration is set to a = -1 m / s². 2 ;

[0062] If the brake pedal opening is P brake Less than 5%, i.e., P brake ≤5% At this point, the vehicle is in a coasting state with no braking force for deceleration. The vehicle's deceleration is mainly due to wind resistance and frictional resistance. The formula for calculating the coasting resistance at this moment is:

[0063] F = 0.5 * p * Cd * A * v 2 +Crr*M*g,

[0064] Where p is the air density, Cd is the vehicle's drag coefficient, A is the vehicle's effective cross-sectional area, Crr is the tire rolling resistance coefficient, M is the vehicle's mass, and g is the acceleration due to gravity; then the vehicle's deceleration is:

[0065] In summary, the specific formula for vehicle deceleration is as follows:

[0066]

[0067] The vehicle controller estimates the vehicle braking time based on the vehicle speed v saved just moments before the drive system communication failure and the calculated vehicle deceleration a. To avoid underestimating the braking time and causing the vehicle speed to not fully drop below 3 km / h, thus triggering a power-off operation, a 10-second time margin is added to the estimated braking time as the actual braking time t, i.e., t = t0 + 10. The vehicle controller determines that the drive is abnormal and the wheel speed signal is unreliable and starts timing. After t seconds, it determines that the current vehicle speed v < 3 km / h and simultaneously performs a vehicle power-off operation.

[0068] (4) Abnormal autonomous high-voltage control of the drive system

[0069] Once the vehicle controller determines the current vehicle status as A and the estimated vehicle speed drops to 3 km / h, the vehicle enters the autonomous power-down process. First, a clear enable operation is performed, where the vehicle controller clears the control enable of all high-voltage accessories to 0. After 0.5 seconds, it sends a high-voltage reduction command to the battery management system. After the battery management system completes the high-voltage reduction operation, the vehicle controller clears the stored vehicle speed signal to zero and simultaneously sends a "Please check the drive system" command to the instrument panel, reminding the driver to stop and perform a check.

[0070] The solution described in this embodiment provides an intelligent connected bus drive system abnormal autonomous power-off control system and method, which effectively solves the problem of autonomously controlling the vehicle to safely reduce high voltage when the intelligent connected bus drive system has communication abnormalities. It effectively avoids vehicle loss of control due to motor communication abnormalities and improves the safety and reliability of the vehicle.

[0071] Example 2:

[0072] The purpose of this embodiment is to provide an intelligent connected bus drive system autonomous power-off control system in case of abnormality.

[0073] An intelligent connected bus drive system abnormal autonomous power-down control system includes:

[0074] A status acquisition unit, which is used to acquire the status of the drive system in real time;

[0075] The vehicle speed estimation unit is used to estimate the vehicle speed based on the vehicle speed saved at the moment before the abnormality when the drive system communication is abnormal, and in combination with the wheel speed sensor signal or brake pedal signal.

[0076] The operating unit is used to perform a high-voltage power-off operation on the vehicle when the estimated vehicle speed is lower than the preset vehicle speed.

[0077] Furthermore, the system described in this embodiment corresponds to the method described in Embodiment 1, and its technical details have been described in detail in Embodiment 1, so they will not be repeated here.

[0078] In further embodiments, the following is also provided:

[0079] An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When executed by the processor, the computer instructions perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0080] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0081] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0082] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0083] The method in Embodiment 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, a detailed description is not provided here.

[0084] Those skilled in the art will recognize that the units, i.e., algorithm steps, of the various examples described in connection with this embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0085] The above embodiments provide a method and system for controlling the abnormal autonomous power-down of a drive system for intelligent connected buses, which has broad application prospects.

[0086] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for autonomous power-down control of an intelligent networked passenger vehicle drive system, characterized in that, include: Real-time acquisition of driver system status; When the drive system communication fails, the vehicle speed is estimated based on the vehicle speed saved at the moment before the failure, combined with wheel speed sensor signals or brake pedal signals. Specifically: The vehicle speed is obtained based on the wheel speed sensor; the difference between the vehicle speed and the average wheel speed of the four wheels is calculated; when the difference is not greater than a preset threshold, the average wheel speed of the four wheels is used as a reference value for vehicle speed estimation. When the difference is greater than a preset threshold, the vehicle speed is estimated based on the vehicle speed saved at the moment before the anomaly and in combination with the brake pedal signal; When the estimated vehicle speed is lower than the preset vehicle speed, the vehicle's high-voltage power-off operation is executed; After the battery management system completes the high-voltage operation, the vehicle controller will clear the stored vehicle speed signal and send a command to the instrument panel to check the drive system, reminding the driver to stop and check.

2. The method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus as described in claim 1, characterized in that, The real-time acquisition of the drive system status specifically involves: after the vehicle completes the connection to the high voltage, periodically receiving drive system message life signals, and determining whether the drive system status is abnormal based on the drive system message life signals.

3. The method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus as described in claim 2, characterized in that, The method of determining whether the drive system status is abnormal based on the drive system message life signal specifically involves: periodically receiving drive system message life signals according to a preset period, determining whether the current life signal is equal to the life signal at the previous moment, and if they are equal, then determining whether the motor is abnormal. Signal loss; when the motor is detected When the signal is lost, a timer starts; if the timer continues for a preset period, the motor is considered to be faulty. If the signal is lost, the drive system communication is determined to be abnormal.

4. The method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus as described in claim 1, characterized in that, The vehicle speed estimation based on the vehicle speed saved at the moment before the anomaly and combined with the brake pedal signal specifically involves: determining the vehicle deceleration based on the obtained brake pedal opening signal, combined with the pre-determined relationship between the vehicle brake pedal opening and the vehicle braking deceleration, and the pre-determined vehicle coasting deceleration when the vehicle is in a coasting state; estimating the vehicle braking time required when the vehicle speed is lower than the preset vehicle speed based on the vehicle speed saved at the moment before the anomaly and the vehicle deceleration; starting from the moment of the drive system communication anomaly, timing is initiated, and when the duration meets the vehicle braking time plus a preset time margin, a high-voltage power-off operation is performed on the vehicle.

5. The method for controlling the abnormal autonomous power-down of a drive system for an intelligent connected bus as described in claim 1, characterized in that, The drive system status includes normal communication between the drive system and the vehicle controller, and abnormal communication between the drive system and the vehicle controller.

6. A smart connected bus drive system abnormal autonomous power-off control system, characterized in that, include: A status acquisition unit, which is used to acquire the status of the drive system in real time; The vehicle speed estimation unit is used to estimate the vehicle speed based on the vehicle speed saved at the moment before the abnormality when the drive system communication is abnormal, and in combination with the wheel speed sensor signal or brake pedal signal. Specifically: The vehicle speed is obtained based on the wheel speed sensor; the difference between the vehicle speed and the average wheel speed of the four wheels is calculated; when the difference is not greater than a preset threshold, the average wheel speed of the four wheels is used as a reference value for vehicle speed estimation. When the difference is greater than a preset threshold, the vehicle speed is estimated based on the vehicle speed saved at the moment before the anomaly and in combination with the brake pedal signal; The operating unit is used to perform a high-voltage power-off operation on the vehicle when the estimated vehicle speed is lower than the preset vehicle speed. After the battery management system completes the high-voltage operation, the vehicle controller will clear the stored vehicle speed signal and send a command to the instrument panel to check the drive system, reminding the driver to stop and check.

7. A computer-readable storage medium having a program stored thereon, characterized in that, When executed by the processor, the program implements the intelligent connected bus drive system abnormal autonomous power-down control method as described in any one of claims 1-5.

8. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the intelligent connected bus drive system abnormal autonomous power-down control method as described in any one of claims 1-5.

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