Safety time interval control strategy and system during driving

Abstract

The invention discloses a safe time interval control strategy and system during driving, and the strategy comprises the steps: starting a safe time interval control function when the current vehicle speed is greater than a first vehicle speed; calculating a vehicle following time interval in real time according to the forward speed of the vehicle and the distance between the vehicle and the front target vehicle; when the car following time interval is smaller than the first time interval or the predicted collision time is smaller than the first time, a prompt is given out; when the car following time interval is smaller than the second time interval or the predicted collision time is smaller than the second time interval, a first braking force is automatically applied to decelerate the car, and when the car following time interval is larger than the third time interval or the predicted collision time is larger than the third time, the first braking force is automatically relieved; wherein the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is shorter than the first time and the third time is longer than the first time. When the conditions are met, the safety time interval control function is started, and the safety sense and the comfort sense of autonomous driving are greatly improved through the function.

Description

Technical Field

[0001] The present application relates to the technical field of automobile driving safety, and more specifically, to a driving safety distance control strategy and system. Background Art

[0002] With the continuous development of intelligent technology, more active and passive safety technologies are being applied to automobiles. Safety has always been a very important point in the development of automobiles in various periods. In recent years, the commonly used safety assisted driving systems include: automatic braking system AEB, adaptive cruise control ACC, smart cruise control system SCC, forward collision warning system FCW, emergency lane keeping system ELK, etc., which detect the surrounding environment of the vehicle through cameras, millimeter wave radars, etc. and identify targets with collision risks, and promptly remind the driver to pay attention to safety, or the vehicle autonomously brakes or avoids to ensure safety. In recent years, the driving experience of active and passive safety has gradually been paid attention to by major OEMs. It has become an inevitable trend in the development of smart cars to be both safe and comfortable without losing driving pleasure.

[0003] At present, many vehicles are equipped with ACC and SCC cruise functions, which use cameras, laser radars, millimeter-wave radars, etc. to detect the vehicle's forward driving environment and realize vehicle intelligent cruise work. This function can keep the vehicle in the lane and follow the vehicle in front. When the current vehicle accelerates, decelerates or stops, the vehicle will also automatically decelerate, stop, start, and accelerate according to the cruise setting speed and the following distance. This function can greatly relieve the driver's driving pressure and workload. However, the ACC / SCC system is rarely used in complex urban road traffic, because there are many vehicles, pedestrians, and intersections in complex urban road traffic. Vehicles need to deal with various vehicles cutting in and out at various intersections and curves, which makes ACC and SCC frequently identify new CIPV targets when used. The hysteresis of taking corresponding deceleration and acceleration will lead to a decrease in driving safety and vehicle traffic efficiency. In addition, the ACC / SCC system will cause the function to exit and enter the standby state after the driver brakes or turns at a large angle, and the driver needs to reactivate the function. Driving on urban roads will cause the system to frequently enter the standby state, and the driver needs to turn it on frequently, resulting in insufficient convenience in using the function.

[0004] There are also FCW and AEB systems, whose main function is to warn of impending collisions ahead and stop the main vehicle in time to avoid collision accidents. The FCW and AEB systems work when the vehicles are about to collide, aiming to trigger warnings and emergency braking in emergency situations to ensure that collisions are avoided or mitigated. However, when the vehicle follows the vehicle in front too closely, the vehicle in front brakes suddenly, and the vehicle may not react in time, resulting in a rear-end collision. Even if AEB is triggered, it may cause an accident in which the vehicle behind the vehicle rear-ends. The AEB function is triggered, mistakenly triggered, or not triggered in time, which will bring a bad driving experience to the driver.

[0005] In summary, the existing vehicle active and passive safety technologies cannot achieve the expected driving safety and comfort, and the user experience is poor. Summary of the invention

[0006] The present application provides a driving safety distance control strategy and system, which starts the safety distance control function when conditions are met. After the function is turned on, it will not affect normal driving, nor will it be frequently exited. The driver can control the acceleration, deceleration and steering of the vehicle at any time. Only when the following distance is too small or the risk of collision is very high, the appropriate braking force is automatically applied to slow down (rather than brake to stop). When the vehicle regains safety, the applied braking force is automatically released and normal driving is resumed. It only plays the role of controlling the vehicle speed and distance, reducing the occurrence of collisions or reducing collision losses, and at the same time greatly improves the sense of safety and comfort of autonomous driving.

[0007] This application provides a safe driving distance control strategy, including:

[0008] When the forward vehicle speed is greater than the first vehicle speed, the safety time distance control function is activated;

[0009] Calculate the following distance in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front;

[0010] When the following vehicle distance is less than the first distance or the estimated collision time is less than the first time, a reminder is issued;

[0011] When the following vehicle time distance is less than the second time distance or the estimated collision time is less than the second time, the first braking force is automatically applied to slow down the vehicle; when the following vehicle time distance is greater than the third time distance or the estimated collision time is greater than the third time, the first braking force is automatically released;

[0012] Among them, the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is smaller than the first time, and the third time is larger than the first time.

[0013] Preferably, when the following time distance is less than the first time distance, the following time distance on the instrument panel is displayed in red.

[0014] Preferably, when the following distance is less than the second distance, the following distance on the instrument panel is displayed in red, and a voice reminder is given that the following distance is less than a threshold.

[0015] Preferably, when the reverse vehicle speed is greater than the second vehicle speed, the safety time distance control function is activated;

[0016] Calculate the estimated collision time in real time based on the vehicle's reversing speed and the distance between it and the target vehicle or obstacle behind it;

[0017] When the estimated collision time is less than the fourth time, the second braking force is automatically applied to decelerate the vehicle; when the estimated collision time is greater than the fourth time, the second braking force is automatically released.

[0018] Preferably, the braking deceleration of the braking force is greater than or equal to a preset deceleration.

[0019] The present application also provides a driving safety time distance control system, including a start condition judgment module, a calculation module, a reminder module and a braking module;

[0020] The start condition judgment module is used to start the safety time distance control function when the forward vehicle speed is greater than the first vehicle speed;

[0021] The calculation module is used to calculate the following distance in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front;

[0022] The reminder module is used to issue a reminder when the following vehicle distance is less than the first distance or the estimated collision time is less than the first time;

[0023] The brake module is used to automatically apply a first braking force to decelerate the vehicle when the following vehicle time distance is less than a second time distance or the estimated collision time is less than the second time, and automatically release the first braking force when the following vehicle time distance is greater than a third time distance or the estimated collision time is greater than the third time;

[0024] Among them, the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is smaller than the first time, and the third time is larger than the first time.

[0025] Preferably, the driving safety time distance control system further comprises an instrument panel, and when the following vehicle time distance is less than the first time distance, the following vehicle time distance on the instrument panel is displayed in red.

[0026] Preferably, when the following distance is less than the second distance, the following distance on the instrument panel is displayed in red, and a voice reminder is given that the following distance is less than a threshold.

[0027] Preferably, the start condition judgment module is further used to start the safety time distance control function when the reverse vehicle speed is greater than the second vehicle speed;

[0028] The calculation module is also used to calculate the estimated collision time in real time based on the reversing speed of the vehicle and the distance between the vehicle and the target vehicle or obstacle behind it;

[0029] The brake module is also used to automatically apply a second braking force to decelerate the vehicle when the estimated collision time is less than a fourth time, and automatically release the second braking force when the estimated collision time is greater than the fourth time.

[0030] Preferably, the braking deceleration of the braking force is greater than or equal to a preset deceleration.

[0031] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0033] Figure 1 Flow chart of the safe driving distance control strategy provided for this application;

[0034] Figure 2 Schematic diagram of the detection range of the camera and radar provided for this application;

[0035] Figure 3 The structural diagram of the safe driving distance control system provided for this application;

[0036] Figure 4 This is a structural diagram of an embodiment of a safe driving distance control system provided by the present application. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0039] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0040] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0041] The present application provides a safe distance control strategy and system during driving. The safe distance control function is activated when conditions are met. After the function is turned on, it will not affect normal driving, nor will it be frequently exited. The driver can control the acceleration, deceleration and steering of the vehicle at any time. Only when the following distance is too small or the risk of collision is very high, the appropriate braking force is automatically applied to slow down (rather than brake to stop). When the vehicle regains safety, the applied braking force is automatically released and normal driving is resumed. It only plays the role of controlling vehicle speed and distance, reducing the occurrence of collisions or reducing collision losses. At the same time, it greatly enhances the sense of safety and comfort of autonomous driving, and is intended to help drivers reduce collisions and reduce collision losses while enjoying the fun and excitement of autonomous driving.

[0042] like Figure 1 As shown, the driving safety distance control strategy provided by this application includes:

[0043] S110: When the forward vehicle speed is greater than a first vehicle speed (eg, 15 kph), a safe distance control function is activated.

[0044] As an embodiment, the safety time interval control function can be turned on or off, or started automatically, in the vehicle system.

[0045] S120: Calculate the following distance in real time based on the forward speed of the own vehicle and the distance between the own vehicle and the target vehicle in front.

[0046] Figure 2 Given the detection range of radar and camera, Figure 2 As shown, the front camera detection area is 0~150M in front of the vehicle; the front radar detection area is 0~70M in front of the vehicle; the left and right radar detection areas are 0~30M in front of the vehicle.

[0047] After the front radar and camera recognize the target vehicle in front, the model of the front vehicle and the following distance will be displayed on the instrument panel. When the following distance is reasonable and there is no risk of rear-end collision, the following distance on the instrument panel will be displayed in green.

[0048] S130: When the following vehicle distance is less than the first distance or the estimated time-to-collision (TTC) is less than the first time, a reminder is issued.

[0049] Preferably, when the following time distance is less than the first time distance, the following time distance on the instrument panel is displayed in red.

[0050] S140: When the following distance is less than the second distance or the estimated collision time is less than the second time, the first braking force is automatically applied to slow down the vehicle; when the following distance is greater than the third distance or the estimated collision time is greater than the third time, the first braking force is automatically released. The first braking force is different from the AEB system. This function does not need to stop the vehicle, but only controls the speed and distance.

[0051] For static or low-speed target vehicles, braking is performed in advance mainly based on TTC. Regardless of whether it is based on the following distance or TTC, whichever reaches the braking working conditions first will trigger braking. The braking deceleration should be ≥ the preset deceleration (for example, -5m / s²) to ensure comfort and safety.

[0052] Preferably, when the following distance is less than the second distance, the following distance on the instrument panel is displayed in red, and a voice reminder is given that the following distance is less than a threshold value (ie, the distance is too close).

[0053] Among them, the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is smaller than the first time, and the third time is larger than the first time.

[0054] Preferably, the driving safety distance control strategy provided by the present application also includes:

[0055] S150: When the reverse vehicle speed is greater than a second vehicle speed (eg, 3 kph), a safe distance control function is activated.

[0056] S160: Calculate the estimated collision time in real time based on the reverse speed of the own vehicle and the distance between the own vehicle and the target vehicle or obstacle behind.

[0057] S170: When the estimated collision time is less than the fourth time, the second braking force is automatically applied to decelerate the vehicle; when the estimated collision time is greater than the fourth time, the second braking force is automatically released.

[0058] Preferably, the driving safety distance control strategy provided by the present application also includes:

[0059] S180: When the forward speed of the vehicle is greater than the third speed when turning, the safe distance control function is activated.

[0060] S190: Calculate the distance and relative speed between the vehicle and surrounding vehicles in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front and the vehicle traveling in the same direction on the side.

[0061] S1100: When the estimated collision time is less than the fifth time, the third braking force is automatically applied to decelerate the vehicle; when the estimated collision time is greater than the fifth time, the third braking force is automatically released.

[0062] Table 1 shows an embodiment of various threshold values ​​when driving forward, reversing, and turning (yaw) of the vehicle.

[0063]

[0064] Based on the above, the present application also provides a safe time distance control system during driving. Figure 3As shown, the driving safety time distance control system includes a start condition judgment module 310 , a calculation module 320 , a reminder module 330 and a braking module 340 .

[0065] The start condition judgment module 310 is used to start the safe headway control function when the forward vehicle speed is greater than the first vehicle speed.

[0066] The calculation module 320 is used to calculate the following distance in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front.

[0067] The reminder module 330 is used to issue a reminder when the following vehicle distance is less than the first distance or the estimated collision time is less than the first time.

[0068] The braking module 340 is used to automatically apply a first braking force to decelerate the vehicle when the following distance is less than a second distance or the estimated collision time is less than the second time, and automatically release the first braking force when the following distance is greater than a third distance or the estimated collision time is greater than the third time.

[0069] The second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval. The second time is smaller than the first time, and the third time is larger than the first time.

[0070] Preferably, the driving safety time distance control system further includes an instrument panel 350 , and when the following vehicle time distance is less than the first time distance, the following vehicle time distance on the instrument panel 350 is displayed in red.

[0071] Preferably, when the following distance is less than the second distance, the following distance on the instrument panel 350 is displayed in red, and a voice reminder is given that the following distance is less than a threshold.

[0072] Preferably, the start condition judgment module 310 is further configured to start the safe headway control function when the reverse vehicle speed is greater than the second vehicle speed.

[0073] The calculation module 320 is also used to calculate the estimated collision time in real time based on the reverse speed of the vehicle and the distance between the vehicle and the target vehicle or obstacle behind.

[0074] The braking module 340 is further configured to automatically apply a second braking force to decelerate the vehicle when the estimated collision time is less than a fourth time, and automatically release the second braking force when the estimated collision time is greater than the fourth time.

[0075] Preferably, the start condition judgment module 310 is further configured to start the safe headway control function when the forward vehicle speed is greater than the third vehicle speed when the vehicle turns.

[0076] The calculation module 320 is also used to calculate the distance and relative speed between the vehicle and surrounding vehicles in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front and the vehicle traveling in the same direction on the side.

[0077] The braking module 340 is further configured to automatically apply a third braking force to decelerate the vehicle when the estimated collision time is less than a fifth time, and automatically release the third braking force when the estimated collision time is greater than the fifth time.

[0078] This application does not restrict the calculation subject of the following distance and expected collision time on the vehicle, the execution subject of the braking force, etc., as long as it is a controller that can realize these functions. The functional system contains many components (MPC module, PDC module, body controller BCM, EPC controller, ICU instrument controller, etc.), but is not limited to this. The system can monitor and control the driving distance and automatically release the brakes at a safe time, and can realize safe driving and reversing of the vehicle, while maintaining stable safety and comfort. The interactive form is not limited to instrument display, voice alarm and other methods. The ultimate goal is to help the driver drive the vehicle safely and eliminate the risk of collision in time, while taking into account driving pleasure and comfort.

[0079] Figure 4 One of the embodiments is given. Figure 4 In the process, the electronic stability control system ESC detects the forward speed and reverse speed. When the forward speed is greater than 15 kph, the safe time distance control function is activated. At this time, the MPC (Multimedia Personal Computer) controller calculates the following distance and the expected collision time (TTC) in real time. When TTC≤1.5s or the following distance ≤0.5S, continuous braking is performed until TTC>1.5s or the following distance>0.5S is released. When the reverse speed is ≥3kph, the safe time distance control function is activated. At this time, the PDC (Parking Distance Control) calculates the expected collision time in real time. When TTC≤1s, continuous braking is performed until TTC>1s, the brakes are released.

[0080] After the safe distance control function of the present application is activated, it can not only identify the vehicles in front and behind and issue an alarm and decelerate, but also warn the vehicles on the side and execute deceleration. All decelerations will be much milder than the automatic braking system AEB system, making it safer when following a vehicle. Slowing down in advance and reasonably controlling the following distance can effectively avoid rear-end collisions caused by following the vehicle too closely. The pursuit of safety and comfort, the full experience of driving fun while ensuring driving safety, has a better sense of driving safety and comfort, and enhances the customer's car experience.

[0081] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A safe distance control strategy for driving, characterized in that: include: When the forward vehicle speed is greater than the first vehicle speed, the safety time distance control function is activated; Calculate the following distance in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front; When the following vehicle distance is less than the first distance or the estimated collision time is less than the first time, a reminder is issued; When the following vehicle time distance is less than the second time distance or the estimated collision time is less than the second time, the first braking force is automatically applied to decelerate the vehicle; when the following vehicle time distance is greater than the third time distance or the estimated collision time is greater than the third time, the first braking force is automatically released; Among them, the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is smaller than the first time, and the third time is larger than the first time.

2. The driving safety distance control strategy according to claim 1 is characterized in that: When the following distance is less than the first distance, the following distance on the instrument panel is displayed in red.

3. The driving safety distance control strategy according to claim 2 is characterized in that: When the following distance is less than the second distance, the following distance on the instrument panel is displayed in red, and a voice reminder is given that the following distance is less than the threshold.

4. The driving safety distance control strategy according to claim 1 is characterized in that: When the reverse speed is greater than the second speed, the safety distance control function is activated; Calculate the estimated collision time in real time based on the vehicle's reversing speed and the distance between it and the target vehicle or obstacle behind it; When the estimated collision time is less than the fourth time, the second braking force is automatically applied to decelerate the vehicle; when the estimated collision time is greater than the fourth time, the second braking force is automatically released.

5. The driving safety distance control strategy according to claim 1 or 4, characterized in that: The braking deceleration of the braking force is greater than or equal to the preset deceleration.

6. A safe time distance control system for driving, characterized in that: It includes a start condition judgment module, a calculation module, a reminder module and a braking module; The start condition judgment module is used to start the safety headway control function when the forward vehicle speed is greater than the first vehicle speed; The calculation module is used to calculate the following distance in real time based on the forward speed of the vehicle and the distance between the vehicle and the target vehicle in front; The reminder module is used to issue a reminder when the following vehicle distance is less than the first distance or the estimated collision time is less than the first time; The braking module is used to automatically apply a first braking force to decelerate the vehicle when the following vehicle time distance is less than a second time distance or the expected collision time is less than the second time, and automatically release the first braking force when the following vehicle time distance is greater than a third time distance or the expected collision time is greater than the third time; Among them, the second time interval is smaller than the first time interval, and the third time interval is larger than the first time interval; the second time is smaller than the first time, and the third time is larger than the first time.

7. The driving safety time distance control system according to claim 6, characterized in that: It also includes an instrument panel, and when the following vehicle time distance is less than the first time distance, the following vehicle time distance on the instrument panel is displayed in red.

8. The driving safety time distance control system according to claim 7, characterized in that: When the following distance is less than the second distance, the following distance on the instrument panel is displayed in red, and a voice reminder is given that the following distance is less than the threshold.

9. The driving safety time distance control system according to claim 6, characterized in that: The start condition judgment module is also used to start the safety time distance control function when the reverse vehicle speed is greater than the second vehicle speed; The calculation module is also used to calculate the estimated collision time in real time based on the reverse speed of the vehicle and the distance between the vehicle and the target vehicle or obstacle behind; The brake module is also used to automatically apply a second braking force to decelerate the vehicle when the expected collision time is less than a fourth time, and automatically release the second braking force when the expected collision time is greater than the fourth time.

10. The driving safety time distance control system according to claim 6 or 9, characterized in that: The braking deceleration of the braking force is greater than or equal to the preset deceleration.

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