A Collision Detection and Protection Control Method for New Energy Vehicles

Abstract

The present invention discloses a method for collision detection and protection control of new energy vehicles, belonging to the field of safety control of new energy vehicles. The collision detection and protection method of the present invention, based on the acquisition of the longitudinal acceleration component, sets a collision trigger flag if the acceleration change threshold is exceeded, and makes a comprehensive judgment within a certain period of time by combining current vehicle state information such as ABS vehicle speed and motor speed. If an actual collision occurs, the high voltage is immediately cut off. The present invention can effectively avoid false alarms caused by sensor failure or signal interference, and can significantly improve the accuracy of collision detection and the protection effect.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle safety control, and more specifically to a collision detection and protection control method for new energy vehicles. Background Art

[0002] With the increase in the market share of new energy vehicles, the society's attention to the safety issues of new energy vehicles has also increased. Different from traditional fuel vehicles, new energy vehicles have high-voltage equipment, and after a collision, it may cause damage to high-voltage devices or wiring harnesses, resulting in high-voltage short-circuit leakage, posing a risk of electric shock or fire, and causing secondary harm to personnel. Therefore, it is necessary to accurately detect the occurrence of a collision and cut off the high voltage in a timely manner to reduce the secondary harm that may be caused after a collision.

[0003] Currently, there are many control methods for new energy vehicle collision detection or protection, but most of them have disadvantages such as low detection accuracy and poor protection effect.

[0004] For example, the Chinese invention patent with the application number 201810798228.8 discloses a collision protection control method and system for electric vehicles. By obtaining vehicle collision information and obtaining an impact force value, when the impact force value is not less than the upper limit threshold, the high voltage is cut off by the vehicle controller; when the impact force value is less than the upper limit threshold and greater than the lower limit threshold, the driving motor power is reduced by the vehicle controller according to a set ratio; when the impact force value is not greater than the lower limit threshold, the vehicle controller outputs a false alarm message. This method does not describe the method of obtaining the impact force value, and the installation of the force sensor has high requirements for the installation position and installation process, and is often limited in actual application, and only a single sensor is used to judge, which may cause false alarms.

[0005] Another example is the Chinese invention patent with the application number CN201810799510.8, which provides a control method and system for electric vehicle collision protection. It mainly includes: after detecting a vehicle collision, when the current vehicle speed value is greater than the set vehicle speed value, only the high voltage of the driving motor is cut off until the vehicle speed is less than the set speed value; when the vehicle speed is less than the set speed value, the high voltage of the whole vehicle is cut off. Although this method classifies the cutting off of high voltage after a collision according to the vehicle speed situation, there are still certain safety hazards in not cutting off the high voltage in a timely manner after a collision, and other methods should be considered to meet the operation of the steering and braking systems.

[0006] For another example, the Chinese invention patent with application number CN202111126740.6 provides a vehicle post - collision protection system and method. By installing multiple collision sensors, which are respectively arranged on the front side, rear side, left side, and right side of the vehicle. After a collision occurs, the controller identifies the collision position according to the current or voltage signals output by each sensor, gives a warning through the instrument, and combines the vehicle speed, gear signal, accelerator pedal signal, and brake pedal opening to take protection measures for the vehicle through the power system controller and the brake system controller. This method takes into account the collision position, but multiple sensors not only increase the cost but also have the possibility of false alarms relying only on sensors. Summary of the Invention

[0007] The present invention provides a collision detection and protection control method for new - energy vehicles to overcome the shortcomings of existing new - energy vehicle collision detection, such as relying only on sensors, having the possibility of false alarms, and having certain potential safety hazards.

[0008] The present invention adopts the following technical solutions:

[0009] A collision detection and protection control method for new - energy vehicles includes the following steps:

[0010] (1) Detect the longitudinal acceleration component of the vehicle;

[0011] (2) If the detected longitudinal acceleration component value is greater than the acceleration change threshold a1, then set the collision trigger flag bit to 1 from the current moment and maintain it for a certain period of time;

[0012] (3) During the period when the collision trigger flag bit is maintained, make the following judgments:

[0013] a) Whether the absolute value of the vehicle's longitudinal acceleration is greater than the set acceleration change threshold a1;

[0014] b) Whether the absolute value of the vehicle acceleration directly calculated from the motor speed is greater than the set threshold a2, where 0 < a2 < a1;

[0015] c) Whether the motor is disconnected;

[0016] d) Whether the absolute value of the change in ABS vehicle speed from the rising edge of the longitudinal collision trigger flag bit after a certain time exceeds the set vehicle speed change threshold;

[0017] e) Whether the vehicle speed is less than the set vehicle speed threshold;

[0018] (4) If all conditions in step (3) are yes, trigger collision protection and perform high - voltage disconnection processing; otherwise, as long as one condition is no, set the collision trigger flag bit to 0 after a certain time, and then repeat steps (2) and (3).

[0019] In a preferred embodiment, when the judgment result of any one of the conditions a), b), and c) in the above step (3) is yes, the collision trigger flag bit is maintained as 1 under the current condition until the collision trigger flag bit is cleared when it becomes 0.

[0020] In a preferred embodiment, before the above step (1), the following steps are further included: The vehicle controller detects that the collision sensor message is online and the signal value is within the valid range.

[0021] In a preferred embodiment, the motor speed of condition b) in the above step (3) needs to be filtered.

[0022] The collision detection and protection control method for a new energy vehicle of the present invention further includes the following steps:

[0023] (5), Detect the vehicle's lateral acceleration component;

[0024] (6), If the detected lateral acceleration component value is greater than the acceleration change threshold a1, set the collision trigger flag bit to 1 from the current moment and maintain it for a certain period of time;

[0025] (7), During the period when the collision trigger marking bit is maintained, the following judgments are made:

[0026] f) Whether the absolute value of the vehicle's lateral acceleration is greater than the set acceleration change threshold a1;

[0027] g) And after a certain time at the rising edge of the lateral collision trigger flag bit, whether the absolute value of the change in the ABS vehicle speed compared to the trigger rising edge exceeds the set vehicle speed change threshold;

[0028] h) And whether the vehicle speed is less than the set vehicle speed threshold;

[0029] (8), If all conditions in step (7) are yes, trigger collision protection and perform the high-voltage cut-off process; otherwise, as long as one condition is no, set the collision trigger flag bit to 0, and then repeat steps (6) and (7).

[0030] Further, when the judgment result of f) in the above step (7) is yes, the collision trigger flag bit is maintained as 1 under the current condition until the collision trigger flag bit is cleared when it becomes 0.

[0031] Further, the high-voltage cut-off processes in the above steps (4) and (8) are controlled and maintained by the VCU until the low-voltage power is cut off by turning off the key or the main switch.

[0032] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following advantages:

[0033] The collision detection and protection method of the present invention, on the basis of collecting acceleration components, sets a collision trigger flag bit if the acceleration change threshold is exceeded, and comprehensively judges in a certain period of time by combining current vehicle state information such as ABS vehicle speed and motor speed. If an actual collision occurs, the high voltage is immediately cut off. Therefore, the present invention can effectively avoid false alarms caused by sensor failure or signal interference, and can significantly improve the collision detection accuracy and protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flowchart of Embodiment 1 of the present invention.

[0035] Figure 2 It is a flowchart of Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] The following describes the specific implementation manners of the present invention with reference to the accompanying drawings. To fully understand the present invention, many details are described below. However, for those skilled in the art, the present invention can be implemented without these details. For well-known components, methods, and processes, no further detailed description will be given below.

[0037] Embodiment 1

[0038] A collision detection and protection control method for a new energy vehicle, referring to Figure 1 , includes the following steps:

[0039] S01. The vehicle control unit VCU detects whether the collision sensor message is online and the signal value is within the effective range. If so, it proceeds to S02.

[0040] S02. Detect the longitudinal acceleration component of the vehicle and judge whether the longitudinal acceleration component value is greater than the acceleration change threshold a1. If so, it proceeds to S03.

[0041] S03. Set the collision trigger flag bit to 1 from the current moment and maintain it for a certain period of time t.

[0042] S04. Make the following judgments during the period when the collision trigger flag bit is maintained:

[0043] a) Whether the absolute value of the vehicle's longitudinal acceleration is greater than the set acceleration change threshold a1;

[0044] b) Whether the absolute value of the vehicle acceleration directly calculated from the motor speed is greater than the set threshold a2, where 0 < a2 < a1;

[0045] c) Whether the motor is offline;

[0046] d) Whether the absolute value of the change in the ABS vehicle speed compared to the trigger rising edge exceeds the set vehicle speed change threshold after a certain time t from the rising edge of the longitudinal collision trigger flag bit;

[0047] e) And whether the vehicle speed is less than the set vehicle speed threshold;

[0048] If all the above conditions are met, enter SO5; otherwise, enter S06.

[0049] S05. The function takes effect, triggering collision protection, the VCU performs high-voltage processing, and maintains it until the next key or the main switch cuts off the low-voltage power.

[0050] S06. After a certain time t, set the collision trigger flag bit to 0, and repeat S02, S03, and S04.

[0051] When the judgment result of any one of the conditions a), b), and c) in the above step S04 is yes, maintain the collision trigger flag bit as 1 under the current condition until the collision trigger flag bit is cleared to 0.

[0052] The motor speed in condition b) of the above step S04 needs to be filtered.

[0053] Embodiment 2

[0054] Refer to Figure 2 , based on the steps of Embodiment 1, this embodiment further includes the following steps:

[0055] S07. Detect the vehicle's lateral acceleration component; and judge whether the value of the lateral acceleration component is greater than the acceleration change threshold a1. If so, enter S08.

[0056] S08. If the detected value of the lateral acceleration component is greater than the acceleration change threshold a1, set the collision trigger flag bit to 1 from the current moment and maintain it for a certain duration t;

[0057] S09. Make the following judgments during the period when the collision trigger annotation bit is maintained:

[0058] f) Whether the absolute value of the vehicle's lateral acceleration is greater than the set acceleration change threshold a1;

[0059] g) And after a certain time t at the rising edge of the lateral collision trigger flag bit, whether the absolute value of the change in the ABS vehicle speed compared to the time of the trigger rising edge exceeds the set vehicle speed change threshold;

[0060] h) And whether the vehicle speed is less than the set vehicle speed threshold;

[0061] If all the above conditions are met, enter S10; otherwise, enter S11.

[0062] S10. The function takes effect, triggering collision protection, the VCU performs high-voltage processing, and maintains it until the next key or the main switch cuts off the low-voltage power.

[0063] S11. After a certain time t, set the collision trigger flag bit to 0, and repeat S07, S08, and S09.

[0064] When the judgment result in f) of the above step S09 is yes, maintain the collision trigger flag bit as 1 under the current conditions until the collision trigger flag bit is cleared to 0.

[0065] This embodiment adds the detection of the lateral acceleration component, and comprehensively judges by combining the current vehicle state information such as the ABS vehicle speed and the motor speed within a certain period of time, which can further improve the accuracy of collision detection and the protection effect.

[0066] The above is only the specific implementation manner of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantive modification made to the present invention using this concept shall fall within the scope of infringement of the protection scope of the present invention.

Claims

1. A method for collision detection and protection control of a new energy vehicle, characterized in that, it includes the following steps: (1), Detect the longitudinal acceleration component of the vehicle; (2), If the detected longitudinal acceleration component value is greater than the acceleration change threshold a1, set the collision trigger flag bit to 1 from the current moment and maintain it for a certain duration; (3), Make the following judgments during the period when the collision trigger annotation bit is maintained: a) Whether the absolute value of the vehicle's longitudinal acceleration is greater than the set acceleration change threshold a1; b) Whether the absolute value of the vehicle acceleration directly calculated from the motor speed is greater than the set threshold a2, where 0 < a2 < a1; c) Whether the motor is offline; d) Whether the absolute value of the change in the ABS vehicle speed compared to the trigger rising edge exceeds the set vehicle speed change threshold after a certain time after the rising edge of the longitudinal collision trigger flag bit; e) Whether the vehicle speed is less than the set vehicle speed threshold; (4), If all conditions in step (3) are yes, trigger collision protection and perform low-voltage disconnection; otherwise, as long as one condition is no, set the collision trigger flag bit to 0 after a certain time, and then repeat steps (2) and (3).

2. A method for collision detection and protection control of a new energy vehicle as described in claim 1, characterized in that: When the judgment result of any one of a), b), and c) in step (3) is yes, maintain the collision trigger flag bit as 1 under the current condition until the collision trigger flag bit is cleared to 0.

3. A method for collision detection and protection control of a new energy vehicle as described in claim 1, characterized in that: Before step (1), it further includes the following steps: The vehicle controller detects that the collision sensor message is online and the signal value is within the effective range.

4. A method for collision detection and protection control of a new energy vehicle as described in claim 1, characterized in that: The motor speed in condition b) of step (3) needs to be filtered.

5. A method for collision detection and protection control of a new energy vehicle as described in claim 1, characterized in that, it further includes the following steps: (5), Detect the lateral acceleration component of the vehicle; (6), If the detected lateral acceleration component value is greater than the acceleration change threshold a1, set the collision trigger flag bit to 1 from the current moment and maintain it for a certain duration; (7), Make the following judgments during the period when the collision trigger annotation bit is maintained: f) Whether the absolute value of the vehicle's lateral acceleration is greater than the set acceleration change threshold a1; g) Whether the absolute value of the change in the ABS vehicle speed compared to the trigger rising edge exceeds the set vehicle speed change threshold after a certain time after the rising edge of the lateral collision trigger flag bit; h) Whether the vehicle speed is less than the set vehicle speed threshold; (8), If all conditions in step (7) are yes, trigger collision protection and perform low-voltage disconnection; otherwise, as long as one condition is no, set the collision trigger flag bit to 0, and then repeat steps (6) and (7).

6. A method for collision detection and protection control of a new energy vehicle as described in claim 5, characterized in that: When the judgment result of f) in step (7) is yes, maintain the collision trigger flag bit as 1 under the current condition until the collision trigger flag bit is cleared to 0.

7. A new energy vehicle collision detection and protection control method according to claim 5, characterized in that: the high-voltage disconnection processing in steps (4) and (8) is controlled and maintained by the VCU until the low-voltage power is cut off by turning off the key or the main switch.

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