An emergency obstacle avoidance control system for a vehicle using EMB independent braking

Abstract

The present invention discloses an emergency obstacle avoidance control system for a vehicle using EMB independent braking, comprising an L2 vehicle perception module, which is used for identifying obstacle information in front of the vehicle, determining a reasonable obstacle avoidance route when the vehicle avoids the obstacle in front, and sensing the obstacle avoidance action applied by the driver on the steering wheel; an EMB braking module, which is used for obtaining the obstacle avoidance action, and starting the corresponding EMB independent braking strategy according to the obstacle avoidance action to assist the driver in controlling the vehicle to complete the emergency obstacle avoidance operation; the present invention completes the obstacle avoidance by independently allocating the braking forces of the four wheels through the EMB control system itself, has low requirements on the driver's driving ability, is not prone to loss of control due to improper operation, and is beneficial to improving the safety performance of the vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle braking, and in particular relates to an emergency obstacle avoidance control system for a vehicle using EMB independent braking. Background Art

[0002] The automobile braking system is an important part of vehicle safety, which allows the driver to control the speed and stop of the vehicle. With the continuous advancement of automobile technology, active safety technology has gradually become an important direction of modern automobile technology development. As a key technology, the automatic emergency braking system can significantly improve the active safety of the car.

[0003] At present, the current emergency obstacle avoidance system usually uses front-wheel steering to change the vehicle's movement route to avoid obstacles. This method has limited capabilities and cannot complete obstacle avoidance at high speeds. It also requires a high level of driving skills from the driver himself, and is prone to causing the vehicle to lose control when returning to the normal route after avoiding obstacles. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an emergency obstacle avoidance control system for a vehicle using EMB independent braking, which realizes emergency obstacle avoidance of the vehicle by applying EMB independent braking control and solves the above technical problems.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An emergency obstacle avoidance control system for a vehicle using EMB independent braking, comprising:

[0007] The L2 vehicle perception module is used to identify obstacles in front of the vehicle and determine the reasonable obstacle avoidance route for the vehicle to avoid the obstacles in front. It is also used to perceive the obstacle avoidance actions applied by the driver on the steering wheel.

[0008] The EMB braking module is used to obtain obstacle avoidance actions and initiate the corresponding EMB independent braking strategy based on the obstacle avoidance actions to assist the driver in controlling the vehicle to complete emergency obstacle avoidance operations.

[0009] Furthermore, an emergency obstacle avoidance control system for a vehicle using EMB independent braking also includes:

[0010] The obstacle avoidance route recommendation module is used to recommend a route to the driver based on a reasonable obstacle avoidance route when the vehicle is avoiding obstacles ahead.

[0011] Furthermore, the L2 vehicle perception module includes:

[0012] An obstacle recognition unit, used to recognize obstacle information in front of the vehicle;

[0013] The obstacle avoidance route determination unit is used to analyze and obtain a reasonable obstacle avoidance route when the vehicle avoids obstacles ahead;

[0014] The obstacle avoidance action sensing unit is used to sense the user's steering wheel rotation operation and determine the driver's obstacle avoidance action based on the rotation operation and the obstacle information in front of the vehicle.

[0015] Further, the EMB brake module performs the following operations:

[0016] Get obstacle avoidance actions;

[0017] If the obstacle avoidance action is to turn the steering wheel to the left, the EMB system brakes the left wheel alone, generating a yaw moment to change the vehicle's route to avoid obstacles. When the vehicle reaches a state where it can avoid obstacles, it controls all wheels to brake at the same time to reduce the vehicle's speed.

[0018] During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from left steering to right steering, it brakes the right wheel alone, generates a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, completing the emergency obstacle avoidance operation;

[0019] If the obstacle avoidance action is to turn the steering wheel to the right, the EMB system brakes the right wheel alone, generating a yaw moment to change the vehicle's route to avoid obstacles. When the vehicle reaches a state where it can avoid obstacles, it controls all wheels to brake at the same time to reduce the vehicle's speed.

[0020] During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from right steering to left steering, it will brake the left wheel alone, generating a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, thus completing the emergency obstacle avoidance operation.

[0021] Furthermore, an emergency obstacle avoidance control system for a vehicle using EMB independent braking further includes a braking anti-rollover module, wherein the braking anti-rollover module performs the following operations:

[0022] S1. Real-time acquisition of the vehicle speed reduction rate at each moment during the obstacle avoidance process;

[0023] S2. Determine whether the vehicle speed reduction rate is greater than the current rate dynamic critical value alarm threshold; if greater, feed back the braking command to the EMB braking module to reduce the braking efficiency of the EMB braking module.

[0024] Furthermore, an emergency obstacle avoidance control system for a vehicle using EMB independent braking also includes:

[0025] Collect the time series value of the vehicle speed reduction rate at each moment V; where, is the speed decrease rate between time point 1 and time point 2;

[0026] Based on the exponentially weighted moving average algorithm, the current rate dynamic critical value alarm threshold is dynamically adjusted and updated according to the time series value V of the vehicle speed reduction rate; wherein, the calculation formula is:

[0027]

[0028] in, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, λ is the smoothing constant, 1≥λ≥0, λ min and λ max is the maximum and minimum value of the preset smoothing constant, and λ min and λ max Satisfy the value range of λ, is the absolute value of the speed reduction rate between time point m and time point m+1, min() is the minimum value return function, is the maximum speed change before the rollover occurs between time point m and time point m+1, is the speed reduction rate between time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m-1 and time point m, m is an integer greater than 0 and less than n. for hour, The value is an initial critical value alarm threshold value preset according to the height of the center of gravity in the initial state of the vehicle.

[0029] Furthermore, an emergency obstacle avoidance control system for a vehicle using EMB independent braking also includes:

[0030] Real-time collection of the crosswind intensity obtained by the vehicle-mounted sensor at every moment;

[0031] Determine the road condition of the current road the vehicle is traveling on through the on-board map;

[0032] The current rate dynamic critical value alarm threshold is adjusted and updated in real time according to the crosswind intensity and road conditions; the calculation formula is:

[0033]

[0034] in, is the new rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, C m+1 is the crosswind intensity of the vehicle at time point m+1, L m+1 is the road surface condition of the current vehicle driving at time point m+1, C' m+1 is the critical value alarm threshold impact value corresponding to the crosswind intensity of the vehicle at time point m+1, L' m+1 is the critical value alarm threshold impact value corresponding to the road surface state of the current vehicle driving road at time point m+1.

[0035] The beneficial effects of the present invention are:

[0036] 1. The yaw moment is generated by the braking force of the two wheels on the same side, and its limit capacity is much higher than that of ordinary steering that relies on the lateral adhesion of the front wheels;

[0037] 2. The control system can independently adjust the braking force of the four wheels to avoid obstacles, which requires low driving ability of the driver and is not prone to loss of control due to improper operation;

[0038] 3. Relying on the vehicle's original L2 perception system, it can accurately judge the safety of the driving route and adopt the optimal route allocation that meets the obstacle avoidance requirements. The braking system minimizes the generation of braking force according to boundary requirements to smooth the obstacle avoidance process while ensuring driving safety.

[0039] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or they may be taught from the practice of the present invention. The purposes and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0040] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 The figure is a schematic diagram of system modules of an emergency obstacle avoidance control system for a vehicle using EMB independent braking in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0044] See also Figure 1 The present invention proposes an emergency obstacle avoidance control system for a vehicle using EMB independent braking, comprising:

[0045] The L2 vehicle perception module is used to identify obstacles in front of the vehicle and determine the reasonable obstacle avoidance route for the vehicle to avoid the obstacles in front. It is also used to perceive the obstacle avoidance actions applied by the driver on the steering wheel.

[0046] The L2 vehicle perception module includes:

[0047] An obstacle recognition unit, used to recognize obstacle information in front of the vehicle;

[0048] The obstacle avoidance route determination unit is used to analyze and obtain a reasonable obstacle avoidance route when the vehicle avoids obstacles ahead;

[0049] The obstacle avoidance action sensing unit is used to sense the user's steering wheel rotation operation and determine the driver's obstacle avoidance action based on the rotation operation and the obstacle information in front of the vehicle;

[0050] The EMB braking module is used to obtain obstacle avoidance actions and initiate the corresponding EMB independent braking strategy according to the obstacle avoidance actions to assist the driver in controlling the vehicle to complete emergency obstacle avoidance operations;

[0051] The EMB brake module performs the following operations:

[0052] Get obstacle avoidance actions;

[0053] If the obstacle avoidance action is to turn the steering wheel to the left, the EMB system brakes the left wheel alone, generating a yaw moment to change the vehicle's route to avoid the obstacle, until the vehicle reaches a state where it can avoid the obstacle. This determines whether there is a risk of collision between the vehicle and the obstacle. If not, the vehicle is determined to have reached a state where it can avoid the obstacle, and controls all wheels to brake at the same time to reduce the vehicle's speed.

[0054] During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from left steering to right steering, it brakes the right wheel alone, generates a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, completing the emergency obstacle avoidance operation;

[0055] If the obstacle avoidance action is to turn the steering wheel to the right, the EMB system brakes the right wheel alone, generating a yaw moment to change the vehicle's route to avoid obstacles. When the vehicle reaches a state where it can avoid obstacles, it controls all wheels to brake at the same time to reduce the vehicle's speed.

[0056] During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from right steering to left steering, it brakes the left wheel alone, generates a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, completing the emergency obstacle avoidance operation;

[0057] The beneficial effects of the above technical solution are as follows: in the prior art, the usual emergency obstacle avoidance method is to use front-wheel steering, relying on the lateral adhesion of the front wheels (similar to friction) to act on the vehicle body to change the direction of the vehicle. However, in the case of emergency and large-scale obstacle avoidance at a high speed, the front wheels have limited ability to provide lateral adhesion and cannot meet the obstacle avoidance route requirements. At the same time, the driver is required to operate the car to return to the normal driving route after the obstacle avoidance is completed. The extreme control of the car before and after the obstacle avoidance can easily cause the vehicle to become unstable and enter an out-of-control state, causing other losses. In addition, in the case of obstacle avoidance, the driver often performs both steering and braking actions at the same time when operating the car. On the one hand, the lateral adhesion of the front wheels is further reduced, and on the other hand, it is easy to cause the vehicle to lose stability and enter an out-of-control state. The control of the vehicle's anti-lock braking system applies unstable braking force to the braking system, reducing the vehicle's control limit. In view of the problems existing in the prior art, the above-mentioned technical scheme is adopted to rely on the braking force of the two wheels on the same side to generate a yaw torque, and its limit capacity is much higher than that of ordinary steering relying on the lateral adhesion of the front wheels. At the same time, the control system itself independently adjusts the braking force of the four wheels to complete obstacle avoidance, which has low requirements on the driver's driving ability and is not easy to cause loss of control due to improper operation. In addition, relying on the vehicle's original L2 level perception system, it can accurately judge the safety of the driving route and adopt the optimal route allocation that meets the obstacle avoidance requirements. The braking system reduces the generation of braking force as much as possible according to the boundary requirements to smooth the obstacle avoidance process while ensuring driving safety.

[0058] In one embodiment, an emergency obstacle avoidance control system for a vehicle using EMB independent braking further includes:

[0059] The obstacle avoidance route recommendation module is used to recommend a route to the driver based on the reasonable obstacle avoidance route when the vehicle avoids the obstacle ahead;

[0060] The working principle and beneficial effects of the above technical solution are: the above solution provides the driver with obstacle avoidance prompts in advance. Since it is an emergency obstacle avoidance, it is recommended that the obstacle avoidance statement be as concise as possible, such as directly stating the direction of turn, "turn left" or "turn right"; this is beneficial to improving the rationality of the obstacle avoidance action applied to the steering wheel in subsequent emergency braking.

[0061] In one embodiment, an emergency obstacle avoidance control system for a vehicle using EMB independent braking further includes a braking anti-rollover module, wherein the braking anti-rollover module performs the following operations:

[0062] S1. Real-time acquisition of the vehicle speed reduction rate at each moment during the obstacle avoidance process;

[0063] S2, determining whether the vehicle speed reduction rate is greater than the current rate dynamic critical value alarm threshold; if greater, feeding back a braking command to the EMB braking module to reduce the braking efficiency of the EMB braking module;

[0064] The working principle and beneficial effects of the above technical solution are as follows: during emergency braking, the degree to which the driver presses down the brake pedal determines the speed at which the vehicle speed decreases. However, it is well known that when the vehicle speed changes too much in a short period of time during turning, there is a risk of the vehicle rolling over, endangering driving safety. In order to reduce the risk of vehicle rollover during emergency braking, this solution also designs a braking anti-rollover module, which is used to monitor the vehicle speed changes in real time during emergency braking, and use a dynamic threshold to compare with the real-time rate. When the vehicle speed changes too fast, the braking command is fed back to the independent EMB braking module to reduce the feedback transmission rate of the brake pedal and the brake positive feedback, thereby reducing the amplitude of the vehicle speed change and preventing the vehicle from rolling over.

[0065] In one embodiment, an emergency obstacle avoidance control system for a vehicle using EMB independent braking further includes:

[0066] Collect the time series value of the vehicle speed reduction rate at each moment V; where, is the speed decrease rate between time point 1 and time point 2;

[0067] Based on the exponentially weighted moving average algorithm, the current rate dynamic critical value alarm threshold is dynamically adjusted and updated according to the time series value V of the vehicle speed reduction rate; wherein, the calculation formula is:

[0068]

[0069] in, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, λ is the smoothing constant, 1≥λ≥0, λ min and λ max is the maximum and minimum value of the preset smoothing constant, and λ min and λ max Satisfy the value range of λ, is the absolute value of the speed reduction rate between time point m and time point m+1, min() is the minimum value return function, is the maximum speed change before the rollover occurs between time point m and time point m+1, is the speed reduction rate between time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m-1 and time point m, m is an integer greater than 0 and less than n. for hour, The value of is the initial critical value alarm threshold value preset according to the height of the center of gravity in the initial state of the vehicle;

[0070] The working principle and beneficial effects of the above technical scheme are as follows: through the above technical scheme, the vehicle's rollover critical value is dynamically adjusted and updated according to the different vehicle postures at different times, that is, the different center of gravity heights, and the rate dynamic critical value alarm threshold at each moment is determined, which is beneficial to improving the accuracy of rollover prevention and control.

[0071] In one embodiment, an emergency obstacle avoidance control system for a vehicle using EMB independent braking further includes:

[0072] Real-time collection of the crosswind intensity obtained by the vehicle-mounted sensor at every moment;

[0073] Determine the road condition of the current road the vehicle is traveling on through the on-board map;

[0074] The current rate dynamic critical value alarm threshold is adjusted and updated in real time according to the crosswind intensity and road conditions; the calculation formula is:

[0075]

[0076] in, is the new rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, C m+1 is the crosswind intensity of the vehicle at time point m+1, L m+1 is the road surface condition of the current vehicle driving at time point m+1, C' m+1 is the critical value alarm threshold impact value corresponding to the crosswind intensity of the vehicle at time point m+1, L' m+1 is the critical value alarm threshold impact value corresponding to the road surface state of the current vehicle driving road at time point m+1;

[0077] The working principle and beneficial effects of the above technical solution are as follows: in the actual braking process, there are many factors that affect the vehicle rollover, such as vehicle stability, handling, vehicle design style, load impact, suspension system, aerodynamics and other external factors, but the most important actual measurable factors are often the crosswind intensity and the road surface condition. Therefore, under the premise that other factors are uncontrollable, when dynamically adjusting the rate dynamic critical value alarm threshold, adding the joint judgment of the crosswind intensity and the road surface condition is beneficial to improve the accuracy of the rate dynamic critical value alarm threshold. Specifically, first, the crosswind intensity at each moment of emergency braking is obtained through the on-board sensor, which is usually integrated It is used for assisting driving in the vehicle's navigation system or safety system, and then the on-board map determines the road condition of the current vehicle driving road. The determination method is preferably determined according to the description of the ground in the map, for example, "the road is a muddy section, drive carefully", or the current section is determined to be a national highway through map positioning, and the corresponding road condition is the default asphalt road or the relevant road information displayed on the navigation of the national highway. Usually, when the system is installed on the vehicle, multiple default roads will be set to correspond to different road types, such as gravel road, asphalt road, muddy road, etc., and then the current rate dynamic critical value alarm threshold is adjusted and updated in real time according to the crosswind intensity and road condition, where C' m+1 is the critical value alarm threshold impact value corresponding to the crosswind intensity of the vehicle at time point m+1, L' m+1 is the critical value alarm threshold impact value corresponding to the road surface state of the current vehicle driving at time point m+1, C' m+1 and L' m+1 It is a fixed value pre-stored in the system, and its unit is the same as Same, only need to determine C m+1 and L m+1 The corresponding call can be made later. The above technical solution is beneficial to improving the accuracy of the alarm threshold of the dynamic critical value of the rate, thereby reducing the probability of vehicle rollover and ensuring the safety of drivers.

[0078] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An emergency obstacle avoidance control system for a vehicle using EMB independent braking, characterized in that: include: The L2 vehicle perception module is used to identify obstacles in front of the vehicle and determine the reasonable obstacle avoidance route for the vehicle to avoid the obstacles in front. It is also used to perceive the obstacle avoidance actions applied by the driver on the steering wheel. The EMB braking module is used to obtain obstacle avoidance actions and initiate the corresponding EMB independent braking strategy according to the obstacle avoidance actions to assist the driver in controlling the vehicle to complete emergency obstacle avoidance operations; The braking anti-rollover module is used to perform the following operations: S1. Real-time acquisition of the vehicle speed reduction rate at each moment during the obstacle avoidance process; S2, determining whether the vehicle speed reduction rate is greater than the current speed dynamic critical value alarm threshold; If it is greater, the braking command is fed back to the EMB braking module to reduce the braking efficiency of the EMB braking module; The method for updating the current rate dynamic critical value alarm threshold includes: Collect the time series value of the vehicle speed reduction rate at each moment V; where, is the speed decrease rate between time point 1 and time point 2; Based on the exponentially weighted moving average algorithm, the current rate dynamic critical value alarm threshold is dynamically adjusted and updated according to the time series value V of the vehicle speed reduction rate; wherein, the calculation formula is: in, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, λ is the smoothing constant, 1≥λ≥0, λ min and λ max is the maximum and minimum value of the preset smoothing constant, and λ min and λ max Satisfy the value range of λ, is the absolute value of the speed reduction rate between time point m and time point m+1, min() is the minimum value return function, is the maximum speed change before the rollover occurs between time point m and time point m+1, is the speed reduction rate between time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m-1 and time point m, m is an integer greater than 0 and less than n. for hour, The value is an initial critical value alarm threshold value preset according to the height of the center of gravity in the initial state of the vehicle.

2. The vehicle emergency obstacle avoidance control system using EMB independent braking according to claim 1, characterized in that: Also includes: The obstacle avoidance route recommendation module is used to recommend a route to the driver based on a reasonable obstacle avoidance route when the vehicle is avoiding obstacles ahead.

3. The emergency obstacle avoidance control system for a vehicle using EMB independent braking according to claim 1, characterized in that: The L2 vehicle perception module includes: An obstacle recognition unit, used to recognize obstacle information in front of the vehicle; The obstacle avoidance route determination unit is used to analyze and obtain a reasonable obstacle avoidance route when the vehicle avoids obstacles ahead; The obstacle avoidance action sensing unit is used to sense the user's steering wheel rotation operation and determine the driver's obstacle avoidance action based on the rotation operation and the obstacle information in front of the vehicle.

4. The emergency obstacle avoidance control system for a vehicle using EMB independent braking according to claim 1, characterized in that: The EMB brake module performs the following operations: Get obstacle avoidance actions; If the obstacle avoidance action is to turn the steering wheel to the left, the EMB system brakes the left wheel alone, generating a yaw moment to change the vehicle's route to avoid obstacles. When the vehicle reaches a state where it can avoid obstacles, it controls all wheels to brake at the same time to reduce the vehicle's speed. During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from left steering to right steering, it brakes the right wheel alone, generates a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, completing the emergency obstacle avoidance operation; If the obstacle avoidance action is to turn the steering wheel to the right, the EMB system brakes the right wheel alone, generating a yaw moment to change the vehicle's route to avoid obstacles. When the vehicle reaches a state where it can avoid obstacles, it controls all wheels to brake at the same time to reduce the vehicle's speed. During obstacle avoidance, if the EMB system senses that the obstacle avoidance action has changed from right steering to left steering, it will brake the left wheel alone, generating a yaw moment to change the vehicle's route so that the vehicle returns to its normal driving route, thus completing the emergency obstacle avoidance operation.

5. The vehicle emergency obstacle avoidance control system using EMB independent braking according to claim 1, characterized in that: Also includes: Real-time collection of the crosswind intensity obtained by the vehicle-mounted sensor at every moment; Determine the road condition of the current road the vehicle is traveling on through the on-board map; The current rate dynamic critical value alarm threshold is adjusted and updated in real time according to the crosswind intensity and road conditions; the calculation formula is: in, is the new rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, is the current rate dynamic critical value alarm threshold corresponding to time point m and time point m+1, C m+1 is the crosswind intensity of the vehicle at time point m+1, L m+1 is the road surface condition of the current vehicle driving at time point m+1, C′ m+1 is the critical value alarm threshold impact value corresponding to the crosswind intensity of the vehicle at time point m+1, L′ m+1 is the critical value alarm threshold impact value corresponding to the road surface state of the current vehicle driving road at time point m+1.

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