Patent Application
20220198934
The present invention relates to an automatic driving decision system and a method thereof, particularly to a vehicle-platooning driving decision system and method thereof.
Generally, a car platoon includes a plurality of cars, each of which has an automatic assisting driving function or an automatic driving function. Taking an example for a front car and a follower car, the follower car follows the front car according to a following condition. The following condition can be a comparison information of car-following speeds and car-following distances. That is, the faster the car-following speed is, the longer the car-following distance is.
Besides, the car platoon drives in one lane of the road; however, there are other cars driving in another lane of the road. Since an interval exists between the front car and the follower car, other cars in another lane may cut into or across the interval between the front car and the follower car from one lane to another lane for overtaking or getting across the follower car. By this way, the follower car will be close to other cars and the front car will be close to other cars, too. Therefore, other cars cannot maintain a safe distance with the front car and the follower car of the car platoon and the risk of the car accident will be risen.
In view of this, the main purpose of the present invention is to provide a vehicle-platooning driving decision system and method thereof to tackle the problem for other cars cutting into an interval between a front car and a follower car from one lane to another lane.
The vehicle-platooning driving decision system of the present invention is applied on a car platoon, which includes a follower car and a front car. The driving decision system for a car platoon includes:
a follower-car controlling device, disposed in the follower car to control the follower car to follow the front car, outputting a follower-car deceleration command to the follower car to control the follower car to decelerate, and wirelessly transmitting a cut-in notification and a follower-car deceleration notification when the follower-car controlling device detects a cut-in event;
a front-car controlling device, disposed in the front car, receiving the cut-in notification and the follower-car deceleration notification transmitted by the follower-car controlling device, outputting a front-car acceleration command to the front car to control the front car to accelerate according to the cut-in notification, and wirelessly transmitting a front-car acceleration notification to the follower-car controlling device when the follower-car controlling device builds a connection with the front-car controlling device;
when the follower-car controlling device detects that the cut-in event has been excluded, outputting a follower-car acceleration command to the follower car to control the follower car to accelerate, and wirelessly transmitting a cut-in-excluded notification and a follower-car acceleration notification to the front-car controlling device; the front-car controlling device outputting a front-car deceleration command to the front car to control the front car to decelerate according to the cut-in-excluded notification, and wirelessly transmitting a front-car deceleration notification to the follower-car controlling device.
The driving decision system for a car platoon of the present invention includes:
controlling a follower car to follow behind a front car according to a following condition via a follower-car controlling device;
the follower-car controlling device detecting whether a cut-in event is generated, if yes, the follower-car controlling device outputting a follower-car deceleration command to the follower car to control the follower car to decelerate, and wirelessly transmitting a cut-in notification and a follower-car deceleration notification;
wherein when the follower-car controlling device builds a connection with a front-car controlling device disposed in the front car, the front-car controlling device receives the cut-in notification and the follower-car deceleration notification, outputs a front-car acceleration command to the front car to control the front car to accelerate, and wirelessly transmits a front-car acceleration notification to the follower-car controlling device according to the cut-in notification;
wherein the follower-car controlling device detects whether the cut-in event has been excluded, if yes, the follower-car controlling device outputs a follower-car acceleration command to the follower car to control the follower car to accelerate, and wirelessly transmits a cut-in-excluded notification and a follower-car acceleration notice to the front-car controlling device;
wherein when the follower-car controlling device builds a connection with the front-car controlling device, the front-car controlling device outputs a front-car deceleration command to the front car to control the front car to decelerate, and wirelessly transmits a front-car deceleration notification to the follower-car controlling device according to the cut-in-excluded notification.
According to the driving decision system for a car platoon and a method thereof of the present invention, when the follower-car controlling device detects the cut-in event, which represents a car in another lane may cut into the interval between the front car and the follower car in the lane, the follower-car controlling device controls the follower car to decelerate according to the cut-in event. In addition, for the front car, according to the traffic situation of the road, for instance, when there are no cars in front of the front car, the front-car controlling device controls the front car to accelerate whereby the distance between the front car and the follower car can be increased so that the other cars can cut into the interval between the follower car and the front car to avoid the follower car hitting the other cars and the other cars hitting the front car. When the other cars drive away, the car platoon returns to the steady state of the car platoon by the deceleration of the front car and the acceleration of the follower car. In summary, the present invention can significantly solve the problem that the other cars cut into or across the interval between the front car and the follower car of the car platoon from one lane to another lane. The detailed embodiment of the present invention will be introduced below.
The vehicle-platooning driving decision system of the present invention is applied to a car platoon. Generally speaking, the car platoon includes a plurality of cars, each of which includes an automatic assisting driving function or an automatic driving function. Please refer to
Please refer to
Connection architecture, obtaining of information, estimating of a car interval distance, a follower-car estimated coordinate, an cut-in decision manner and an information synchronism mechanism of the follower-car controlling device 10 and the front-car controlling device 20 (or further including the background host 30) are respectively described in detail below.
The follower-car controlling device 10 may be an electronic control unit (ECU) or a car computer, performing an information algorithm and a following-car decision/controlling function. The follower-car controlling device 10 is disposed in the follower car B and signally connected to a follower-car communication device 11, a follower-car sensing device 12, and a follower-car information device 13 disposed in the follower car B.
The follower-car communication device 11 includes a follower-car V2V (vehicle-to-vehicle) communication module 110 or further includes a follower-car mobile communication module 111. The follower-car V2V communication module 110 implements the communication between one car and another. The follower-car V2V communication module 110 can be, but not limited to, the dedicated short range communication module (DSRC) or may be operated on the fourth generation mobile communication technology (4G), the fifth generation mobile communication technology (5G), or the advanced next generation mobile communication technology. The follower-car mobile communication module 111 implements the communication between the car and the other devices (Vehicle-to-everything, V2X). The follower-car mobile communication module 111 may be operated on the fourth generation mobile communication technology(4G), the fifth generation mobile communication technology(5G), or the advanced next generation mobile communication technology. The follower-car sensing device 12 is utilized to sense the peripheral environment information and the position of the follower car B. For example, please refer to
The operating principle of the front-car controlling device 20 is similar to the follower-car controlling device 10. In brief, the front-car controlling device 20 is disposed in the front car A and connected to a front car communication device 21, a front-car sensing device 22 and a front car information device 23 disposed in the front car A by a signal. The front car communication device 21 includes a front-car V2V communication module 210 or further includes a front-car mobile communication module 211. The front-car sensing device 22 outputs a front-car sensing information D_fs. The front-car sensing information D_fs includes a front-car positioning coordinate and a second relative distance. The second relative distance indicates the relative distance sensing value between the front car A and an object in back of the front car A, wherein the position of the front car A is defined as the initial position. In normal conditions of following the car, the object in back of the front car A is the follower car B, and the second relative distance is the relative distance sensing value between the front car A and the follower car B. The front-car controlling device 20 can retrieve a front-car local information D_fv of the front car A from the front car information device 23. The front-car local information D_fv includes a front car acceleration, a front car deceleration, a front-car speed and a front-car steering angle and so on.
In above descriptions, the follower-car sensing device 12 and the front-car sensing device 22 may respectively include a satellite positioning system, a three-dimensional light detection and ranging (3D LiDAR), a two-dimensional light detection and ranging (2D LiDAR), a camera, a real-time kinematic (RTK), and an inertial measurement unit (IMU), but are not limited thereto. Hence, the follower-car sensing device 12 generates the follower-car sensing information D_rs, and the front-car sensing device 22 generates the front-car sensing information D_fs.
When the follower-car V2V communication module 110 builds a connection with the front-car V2V communication module 210, the follower-car controlling device 10 may communicate with the front-car controlling device 20 by a bi-directional communication. Please refer to
The background host 30 may be a cloud server communicating with the follower-car controlling device 10 and the front-car controlling device 20. For example, when the follower-car mobile communication module 111 builds a connection (such as via Internet) with the background host 30, the follower-car controlling device 10 may communicate with the background host 30 by a bi-directional communication via the follower-car mobile communication module 111. Similarly, while the front-car mobile communication module 211 builds a connection (such as via Internet) with the background host 30, the front-car controlling device 20 may communicate with the background host 30 by a bi-directional communication via the front-car mobile communication module 211.
As mentioned above, in the embodiments of the present invention, the background host 30 communicates with the follower-car controlling device 10 and the front-car controlling device 20, and there is a connection between the follower-car controlling device 10 and the front-car controlling device 20. Consequently, there are multiple methods to transmit information performed in parallel in the present invention. That is, when the follower-car controlling device 10 and the front-car controlling device 20 communicate with each other, they respectively simultaneously transmit information to the background host 30. In the embodiments of the present invention, the follower-car controlling device 10 and the front-car controlling device 20 may utilize the V2V communication as the main communication method. When the V2V communication is disconnected, the follower-car controlling device 10 and the front-car controlling device 20 communicate with each other via the background host 30. That is, the background host 30 is utilized as a medium for transmitting information.
Generally speaking, with reference to
When the car platoon is going, transmitting information between the follower-car controlling device 10 and the front-car controlling device 20 and calculating information by the follower-car controlling device 10 need to take some time since the front car A and the follower car B are driving. Therefore, in the embodiments of the present invention, to avoid the follower-car controlling device 10 performing the current following car decision according to the earlier information, the follower-car controlling device 10 further calculates the estimated car interval distance (DRF), which indicates the relative distance between the follower car B and the front car A. The details are described below.
The follower-car controlling device 10 presets a time interval value Δt_seg, a tolerable error range ΔE, a first weight value W1, a second weight value W2, and a third weight value W3 preset by the user. The relation between the car speed and the tolerable error range ΔE is a negative correlation. That is, the faster the car drives, the narrower the tolerable error range ΔE is, which can make sure the distance tolerance is less at the faster speed. The tolerable error range ΔE is calculated according to a reference distance value U (meter) and a percentage value V(%). The minimum of the tolerable error range ΔE is U−U×V %. The maximum of the tolerable error range ΔE is U+U×V %. The reference distance value U and the percentage value V are predetermined values.
As aforementioned descriptions, the follower-car controlling device 10 obtains the first relative distance (defined as D_x herein) from the follower-car sensing information D_rs. The first relative distance D_x indicates the relative distance sensing value between the follower car B and the front car A, wherein the position of the follower car B is defined as an initial position. The follower-car controlling device 10 obtains the second relative distance (defined as D_y herein) from the front-car information package P_f. The second relative distance D_y indicates the relative distance sensing value between the front car A and the follower car B, wherein the position of the front car A is defined as an initial position. The follower-car controlling device 10 calculates an estimated shift distance Dp. W1, W2, and W3 respectively represent weight values less than 1 and W1+W2+W3≤1. The time interval value Δt_seg represents an elapsed time or further includes a delay time that the front-car information package P_f is transmitted from the front-car controlling device 20 to the follower-car controlling device 10 and so on. For instance, Δt_seg may be preset as 100-200 milliseconds. The estimated shift distance Dp is represented as Dp=S·Δt_seg, wherein S is the car-following speed of the follower-car local information D_rv received by the follower-car controlling device 10. The follower-car controlling device 10 calculates the estimated car interval distance DRF according to the first relative distance D_x, the second relative distance D_y, and the estimated shift distance Dp corresponding to the weight value W1, W2, W3.
The below descriptions are according to the prerequisite that the communication between the follower-car controlling device 10 and the front-car controlling device 20 is normal, and the follower-car sensing device 12 operates normally. With reference to
In step S01, when the follower-car controlling device 10 determines that the value of |D_x−Dp| exceeds the tolerable error range ΔE, this indicates that the difference between the first relative distance D_x and the estimated shift distance Dp is greater. Hence, the follower-car controlling device 10 further determines whether the value of |D_x−D_y| exceeds the tolerable error range ΔE (step S02). In step S02, when the follower-car controlling device 10 determines that the value of |D_x−D_y| exceeds the tolerable error range ΔE, which indicates the difference between the first relative distance D_x and the second relative distance D_y is greater. The estimated car interval distance DRF calculated by the follower-car controlling device 10 is defined as a first estimated car interval distance DRF1.In contrast, in step S02, when the follower-car controlling device 10 determines that the value of |D_x−D_y| does not exceed the tolerable error range ΔE, which indicates that the difference between the first relative distance D_x and the second relative distance D_y is low. The estimated car interval distance DRF calculated by the follower-car controlling device 10 is defined as a second estimated car interval distance DRF2.
In step S01, when the follower-car controlling device 10 determines that the value of |D_x−D_y| does not exceed the tolerable error range ΔE, this indicates that the difference between the first relative distance D_x and the estimated shift distance Dp is low. Therefore, the follower-car controlling device 10 further determines whether the value of |D_x−D_y| exceeds the tolerable error range ΔE(step S03). In step S03, when the follower-car controlling device 10 determines that the value of |D_x−D_y| exceeds the tolerable error range ΔE, the estimated car interval distance DRF calculated by the follower-car controlling device 10 is defined as a third estimated car interval distance DRF3. In contrast, in step S03, when the follower-car controlling device 10 determines that the value of |D_x−D_y| does not exceed the tolerable error range ΔE, the estimated car interval distance DRF calculated by the follower-car controlling device 10 is defined as a fourth estimated car interval distance DRF4.
For example, the first estimated car interval distance DRF1 may be expressed as below:
DRF1=W1×D_x+W2×D_y+W3×Dp, it can be seen that Dx, Dy, and Dp are adjusted according to the weights. If the user considers a presetting weight is that D_x is the priority, D_y is after that, and Dp is the last order, the proportion of the weights may be set as W1>W2>W3. For instance, if W1+W2+W3=1, in an embodiment, W1 can be set as 0.5, W2 can be set as 0.33, and W3 can be set as 0.17. In other words, D_x occupies 50% of DRF1, D_y occupies 33% of DRF1, and Dp occupies 17% of DRF1.
For instance, the second estimated car interval distance DRF2 may be expressed as below:
DRF2=W1×Da+W2×Db+W3×Dc, wherein W3<W1, and W3<W2. Consequently, when the follower-car controlling device 10 determines DRF=DRF2, the follower-car controlling device 10 determines that the closest two weight values are respectively as Da and Db, and another weight value is as Dc among D_x, D_y and Dp. The follower-car controlling device 10 adjusts the weight value W1, W2 of Da and Db to be higher, and adjusts the weight value W3 of Dc to be lower. For instance, when the variation of D_x and D_y is less than the variation of D_x and Dp, and the variation of D_x and Dp is less than the variation of D_y and Dp, D_x and D_y are closest to each other and are respectively as Da and Db, and Dp is as Dc.
For instance, the third estimated car interval distance DRF3 may be expressed as below:
DRF3=W1×D_x+W2×D_y+W3×Dp, wherein W2<W1, and W2<W3. When the follower-car controlling device 10 determines DRF=DRF3, the follower-car controlling device 10 adjusts the weight value of the second relative distance D_y to be lower.
For instance, the fourth estimated car interval distance DRF4 may be expressed as below:
DRF4=(W1×D_x+W2×D_y+W3×Dp)/(W1+W2+W3). When the follower-car controlling device 10 determines DRF=DRF4, the follower-car controlling device 10 averages the weight values for D_x, D_y and Dp.
Referring to
For the cut-in event determined by the present invention, taking the follower-car controlling device 10 as an example, as mentioned above, the follower-car controlling device 10 obtains the first relative distance from the follower-car sensing information D_rs. The first relative distance indicates the relative distance sensing value between the follower car B and an object in front of the follower car B, wherein the position of the follower car B is defined as an initial position; besides, the follower-car controlling device 10 obtains the second relative distance from the front-car information package P_f, wherein the second relative distance indicates the relative distance sensing value between the front car A and an object in back of the front car A, wherein the position of the front car A is defined as an initial position.
The follower-car controlling device 10 determines whether the variation of the first relative distance in a unit time is more than or equal to a first threshold, and determines whether the variation of the second relative distance in the unit time is more than or equal to a second threshold, wherein the first threshold may be the same as or different from the second threshold. For instance, in the normal situation for the follower car B following the front car A, the first relative distance and the second relative distance are stable. Hence, the variation of the first relative distance in the unit time is less than the first threshold, and the variation of the second relative distance in the unit time is less than the second threshold. In other words, in the normal situation for the follower car B following the front car A, the first relative distance and the second relative distance should be close to a distance dl as shown in
When the stranger car C in another lane cuts into the car interval between the follower car B and the front car A, the follower-car controlling device 10 detects the stranger car C in another lane to decelerate abruptly. In the meantime, the first relative distance suddenly becomes the relative distance sensing value between the follower car B and the stranger car C, as a distance d2 shown in
When the follower-car controlling device 10 simultaneously determines that the variation of the first relative distance in a unit time is more than or equal to the first threshold, and determines the variation of the second relative distance in a unit time is more than or equal to the second threshold, the follower-car controlling device 10 determines that the cut-in event is generated. The determination of the cut-in event in the present invention correlates to the first relative distance sensed by the follower-car sensing device 12 and the second relative distance sensed by the front-car sensing device 22; therefore, the present invention estimates the relative distance of the follower car B and the front car A to double check so that the determination of the cut-in event is more accurate.
Referring to
When the follower-car controlling device 10 builds a connection with the front-car controlling device 20, the front-car controlling device 20 receives the cut-in notification N1 and the follower-car deceleration notification N2 transmitted by the follower-car controlling device 10. Referring to
Because the follower car B has decelerated and the front car A has accelerated, the car interval between the follower car B and the front car A has been extended. Consequently, the car C can drive between the follower car B and the front car A to sustain the car platoon in the present lane. In the meantime, the follower car B follows the stranger car C in the present lane behind the stranger car C and obeys the following condition 100.
Moreover, referring to
Please refer to
Because the follower car B has accelerated and the front car A has decelerated, the car interval between the follower car B and the front car A has been decreased so that the follower-car controlling device 10 of the follower car B stably follows the front car A behind the front car A according to the following condition 100.
The aforementioned descriptions relate to the decision for the stranger car C cutting into the car platoon. On the other hand, the follower-car controlling device 10 controls the follower car B to accelerate or to decelerate according to the variation of the estimated car interval distance. Referring to
As mentioned above, the front-car controlling device 20 periodically transmits the front-car information package to the background host 30 and the follower-car controlling device 10. The background host 30 and the follower-car controlling device 10 of the present invention implement an information synchronization mechanism, which determines whether a plurality of the front-car information packages P_f received by the background host 30 and the follower-car controlling device 10 are continuous packages or have a delayed time to confirm the effectivity of the plurality of the front-car information packages P_f transmitted by the front-car controlling device 20.
Referring to
For convenience to explain, two front-car information packages sequentially received by the front-car controlling device 20 are respectively defined as a first front-car information package and a second front-car information package. The front-car controlling device 20 retrieves the package serial number of the first front-car information package as a first front-car package serial number, the package serial number of the second front-car information package as a second front-car package serial number, and the local time 503 as a front-car local time.
The front-car controlling device 20 adds the accumulative value to the first front-car package serial number to form a front-car prediction serial number. The accumulative value will be, for example, “1”. According to the result of comparing the front-car prediction serial number and the second front-car package serial number, and a time difference with a system time of the background host 30 or a follower car local time of the follower-car controlling device 10 contrasted with the front car local time of the second front-car information package, the effectivity of the plurality of the front-car information package P_f transmitted by the front-car controlling device 20 is confirmed.
Whereby, when the result of comparing the front-car prediction serial number with the second front-car package serial number is not a continuous serial number, such as when the front-car prediction serial number is “100”, but the second front-car package serial number is “109”, the front-car controlling device 20 determines that there is another missed package between the first front-car information package and the second front-car information package. On the other hand, when the time difference between the follower car local time of the follower-car controlling device 10 and the front car local time of the second front-car information package exceed a threshold time, the front-car controlling device 20 determines that there is another delayed package between the first front-car information package and the second front-car information package. When there is another missed package or delayed package, the information synchronization mechanism determines that the effectivity of the package transmitted by the front-car controlling device 20 is lower. For instance, if the background host 30 determines that the effectivity for transmitting packages is lower, it is determined that the front-car controlling device 20 disconnects from the follower-car controlling device 10.
In summary, when the car in another lane cuts into the interval between the front car and the follower car in the present lane, the present invention controls the follower car to decelerate. For the front car, in allowable situations (such as there is no car in front of the front car), the present invention controls the front car to accelerate to moderately prolong the distance between the front car and the follower car to avoid the accident. When the car cuts in and drives away from the present lane, the front car is to decelerate and the follower car is to accelerate to sustain the driving stability of the car platoon. On the other hand, the present invention responds to the real relative distance between the front car and the follower car via the estimated car interval distance to provide the follower-car controlling device to accurately refer to the real relative distance between the follower car and the front car. The present invention further estimates the effectivity for transmitting packages via the information synchronization mechanism to ensure the efficiency for following car decision.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
