TWI620677B - Automatic control method for vehicle lane change - Google Patents

Abstract

The invention relates to an automatic control method for a vehicle switching lane. After determining the lane environment by detecting the sensor provided on the vehicle body, the present invention provides a preset path for changing lanes, and lights up and changes the lane warning number. After that, the vehicle starts to switch the lane, and executes the fuzzy control algorithm in the process of switching lanes to output the steering wheel rotation angle ratio and the ratio of the throttle to the brake; 俾 continuously feedback control the steering wheel rotation angle ratio and the throttle and brake The ratio is to continuously control the lane switching action of the vehicle until the lane switching is completed.

Description

Automatic control method for vehicle switching lane

The invention relates to an automatic control method for a vehicle switching lane, in particular to an output data using a fuzzy control technology to control a steering wheel rotation angle ratio and a ratio of a throttle to a brake, so that the vehicle automatically and safely completes the lane switching operation innovation. method.

Autopilot technology has become a trend in vehicle transport vehicles, and it is more likely to become a necessary vehicle transport vehicle in the future. This is because vehicle transport vehicles will reduce traffic accidents due to changes in autonomous driving technology and make vehicles more driven. safety.

Therefore, in order to seek a safer driving style and a more efficient road use environment, major automakers have been actively involved in the development of automatic assisted driving or automatic driving systems so that the vehicle can automatically assist the driver in making decisions or intervention in controlling the vehicle. To achieve the goal of avoiding accidents directly.

For example, the Temporary Auto Pilot (TAP) developed by Flowserve Motors can automatically control the acceleration and braking of the vehicle at a speed of 130 kilometers per hour. The TAP system includes radar, camera, and ultrasonic sensor components, which are designed to ensure the safety of the vehicle through the implementation of the TAP system, mainly under the supervision of the driver. However, the TAP technology developed by Flowserve is not intended to completely replace the driver's role, but to help drivers achieve easier and safer driving experience.

At present, major automakers are further developing for autonomous autopilot technology. The so-called autonomous automatic driving means that the vehicle decides the action to be taken without the help of human beings to complete the driving target. Therefore, motion planning is the most important and basic problem that autonomous autopilot must overcome. How to plan a path that does not encounter obstacles between the starting point and the end point to ensure the safety of driving. It is an important subject of autonomous automatic driving technology.

Please refer to China's certificate numbers TW I365145, I434239 and I535589, all of which are techniques for revealing the automatic driving of vehicles. Among them, TW I365145 discloses a way to identify the image features in the image as the lane offset assist/alarm when the mobile vehicle is moving forward, and generate the mobile vehicle auxiliary trajectory when the vehicle retreats and view the distance according to the estimated distance. Method and system for viewing angles or issuing warning messages. TW I434239 is about sensing image information behind the vehicle to define a region of interest corresponding to a left lane, a right lane and the lane, and detecting whether there is a directional light flashing in the three regions of interest. In order to determine whether there is a possibility of harm to the rear of the car, and At the time, the driver of the vehicle is alerted, and the driver is reminded of the relative distance between the vehicle and the rear vehicle to improve the driver's alertness to the driving environment during driving. As for the TW I535589, it integrates with the vehicle's control system and continuously detects the surrounding environment of the vehicle. It also finds the same vehicle as the destination of the vehicle and follows the vehicle in an automatic driving manner to automatically drive the vehicle to the destination. The active automatic driving assistance system and method for identifying the driving direction and driving state of the preceding vehicle by early identification of the preceding vehicle direction light, reducing the collision between the emergency brake and the vehicle and improving the driving efficiency.

The above TW I365145 and TW I434239 are technical developments on how to make the vehicle not deviate from the lane and whether the safe distance between the main vehicle and the rear vehicle is maintained, while the TW I535589 is a follow-up technology.

See also TW I490520, which proposes a microwave technology to apply the Doppler Effect to the antenna system, to help detect the presence or absence of vehicles in front of and behind the adjacent lanes, and to determine whether the driving distance is outside the specified safety distance. . The antenna microwave technology can be used to detect the position of the vehicle in front of and behind the adjacent lane, and the Doppler effect can be shifted from the frequency of the transmitted signal to the frequency of the received reflected signal, and the speed of the vehicle to be tested can be known. By comparing the own vehicles with each other, it is estimated whether the preset safety distance is maintained between the vehicle and the vehicle after the lane is switched.

Now, the present inventors have developed the present invention in view of the fact that the driverless car will become the mainstream in the future, and all new cars will have some automatic driving functions in the future.

The main object of the present invention is to provide an automatic control method for a vehicle switching lane, which is mainly to convert the sensor sensing data into an appropriate navigation road and obstacles and related signs, thereby appropriately correcting the driving direction, the throttle and the braking, and avoiding Because of the traffic accidents caused by human factors such as too close driving distance, distracted driving and dangerous driving, the purpose of safe obstacle avoidance and safe navigation is achieved.

The object and the effect of the present invention are achieved by the following technologies: an automatic control method for a vehicle switching lane, comprising the following steps: a lane environment determining step, detecting the surrounding environment of the vehicle according to at least one sensor installed in a vehicle The obtained environmental information determines whether the lane can be changed; and provides a step of changing the lane preset path, and when determining that the lane can be changed, a preset path of the lane is changed, so that the vehicle performs lane switching according to the preset path. Where the mathematical equation for the transition to the right lane is:

The mathematical equation for the change to the left lane is:

Where x _g is the longitudinal position of the vehicle and y _g is the lateral position of the vehicle, Is the preset path, exp is an exponential function, l ₁ is a lane change lateral path distance parameter, ρ ₁ is a lane change bending parameter, l _c is a lane change longitudinal path distance parameter; lighting step of changing a lane notice light step, according to Converting the preset path of the lane to illuminate the directional light of the corresponding side of the vehicle; continuously outputting the ratio of the steering wheel rotation angle and the ratio of the throttle to the brake, according to the current displacement state of the vehicle and the preset path of the lane change The error is fuzzy controlled to obtain the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable, and then the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable are defuzzified. The steering wheel rotation angle ratio and the throttle to brake ratio are obtained, and the vehicle corrects the steering wheel rotation angle and the throttle and brake output according to the obtained steering wheel rotation angle ratio and the throttle to brake ratio, so that the driving dynamics of the vehicle conform to the Preset path.

The automatic control method for a vehicle switching lane as described above, wherein the environmental information around the vehicle includes a lane image, a front vehicle distance, a distance from a vehicle on the left and/or right lane, and a left and/or right lane The speed of the vehicle.

The automatic control method for a vehicle switching lane as described above, wherein the sensor is one or more of a radar, an optical radar, a global positioning system (GPS), a camera, and a camera.

The automatic control method for a vehicle switching lane as described above, wherein the input of the fuzzy control is: The fuzzy inference rules are: If η _A1 Δy _g =A ₁ and η _B1 △(△y _g )=B ₁ , then u _δ =C ₁ ,If η _A2 Δy _g =A ₂ and η _B2 △(△ y _g )=B ₂ , then u _OB =C ₂ ; where Δ(Δy _g )=Δy _g (k)−Δy _g (k-1), Δy _g (k) represents the current data, △ y _g (k-1) represents the previous data; the parameters η _A1 , η _A2 and η _B1 , η _B2 are normalization factors, and the fuzzy numbers A ₁ , A ₂ , B ₁ , B ₂ , C ₁ , C ₂ represent statements State; the arithmetic expression of the fuzzy inference rule is as follows: If(η _A1 Δy _g , η _B1 △(Δy _g ))is A ₁ ×B ₁ , then u _δ is C ₁

among them, And If(η _A2 Δy _g , η _B2 Δ(Δy _g ))is A ₂ ×B ₂ , then u _OB is C ₂

among them,

The statement states are: positive (PB), medium (PM), positive (PS), zero (ZE), negative (NS), negative (NM), negative (NB).

The automatic control method for a vehicle switching lane as described above, wherein the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable defuzzification system adopt a gravity center defuzzification, and the formula is:

Among them, η _C1 and η _C2 are denormalization factors, u _δ is the steering wheel rotation angle ratio, u _OB is the output ratio of throttle and brake, if it is positive, it means stepping on the throttle, if it is negative, it means pedaling.

(11) ‧‧‧ Lane environment judgment steps

(12) ‧ ‧ Provide a step to change lane preset path

(13) ‧‧‧Lighting the lane change notice step

(14) ‧‧‧Continuous output steering wheel rotation angle ratio and throttle to brake ratio step

First: Flowchart of the steps of the automatic control method for the vehicle switching lane of the present invention

Figure 2: Schematic diagram of the preset path for changing lanes

Third figure: Schematic diagram of fuzzy control of the lane change of the present invention

The fourth picture: the attribution function diagram of the fuzzy control revealing the angle of rotation of the steering wheel

Figure 5: The attribution function diagram of fuzzy control revealing the ratio of throttle to brake

Figure 6: Flow chart of the preset path for automatically controlling the vehicle to switch to the right lane by the method of the present invention

Figure 7: Flowchart for automatically controlling the preset path of the vehicle to switch to the left lane by the method of the present invention

For a more complete and clear disclosure of the technical content, the purpose of the invention and the effects thereof achieved by the present invention, the following is a detailed description, and please refer to the illustrated drawings and drawings: please refer to the first The figure shows the automatic control side of the vehicle switching lane of the present invention. Step flow chart

The automatic control method for the vehicle switching lane of the present invention comprises the following steps: a lane environment determining step (11), a step of providing a lane change preset path (12), a step of lighting the lane change notice number (13), and a continuous output steering wheel. The rotation angle ratio and the ratio of the throttle to the brake step (14); wherein: the lane environment determination step (11) is to install at least one sensor in the vehicle, and the sensor detects the surrounding environment of the vehicle, and thereby obtains the surroundings of the vehicle According to the environmental information, the on-board microcomputer determines whether the vehicle can or needs to change lanes according to the environmental information; wherein the environmental information around the vehicle includes the lane image, the distance of the preceding vehicle, and the distance from the vehicle on the left and/or right lane. , the speed of the vehicle on the left and / or right lane; and the sensor can be one or more of radar, optical radar, global positioning system (GPS), camera, camera; among them, radar, optical radar system For positioning and obstacle detection, the Global Positioning System (GPS) is used for positioning, cameras and cameras are used for object recognition based on deep learning and Bit auxiliary.

Providing a step (12) of changing the lane preset path, when the onboard microcomputer determines that the lane can be changed, the preset path of the lane is changed according to the environment information (refer to the second figure), so that the vehicle follows the preset provided. The path performs lane switching; wherein, the mathematical equation for the vehicle's intended path from the current lane to the right lane is:

The mathematical equation for the vehicle's intended path from the current lane to the left lane is:

Where x _g is the longitudinal position of the vehicle and y _g is the lateral position of the vehicle, Is the preset path, exp is an exponential function, l ₁ is a lane change lateral path distance parameter, which is a positive parameter with a right lateral path and a negative parameter with a left lateral path, and ρ ₁ is a lane change curve The parameter, l _c is the lane change longitudinal path distance parameter; the step of lighting the lane change notice light step (13) is to change the lane to the right or change the lane to the left according to the preset path provided by the on-board microcomputer, further lighting the direction When the right lane is changed or the lane is changed to the left, the vehicle corresponds to the side direction light to notify the rear car to pay attention to the vehicle to perform lane change; the output steering wheel rotation angle ratio and the throttle to brake ratio step (14), in the vehicle When starting the lane change according to the preset path, the onboard microcomputer will further perform fuzzy control according to the error between the current displacement state of the vehicle and the preset path provided by the system (please refer to the third figure) to obtain the steering wheel rotation angle proportional control. Output fuzzy variable and throttle and brake ratio control output fuzzy variable, and then control the output fuzzy variable and oil for the steering wheel rotation angle proportionally Deviation is performed with the brake ratio control output fuzzy variable, and the steering wheel rotation angle ratio and the throttle to brake ratio are respectively obtained, and the vehicle corrects the steering wheel rotation angle (δ) and the throttle (OIL) according to the obtained steering wheel rotation angle ratio and the throttle and brake ratio. And the BRAKE output, such that the driving dynamics of the vehicle are repeatedly performed in accordance with the preset path until the vehicle completes the lane change action.

Wherein, when the fuzzy control of the error between the current displacement state of the vehicle and the preset path provided by the system is performed, the input of the fuzzy control is: The steering inference angle proportional fuzzy inference rule is: If η _A1 Δy _g = A ₁ and η _B1 △ (Δy _g ) = B ₁ , then u _δ = C ₁ , where △ (Δy _g ) = Δy _g ( k)-Δy _g (k-1), Δy _g (k) represents the current data, Δy _g (k-1) represents the previous data; parameters η _A1 and η _B1 are normalization factors, fuzzy number A ₁ , B ₁ , C ₁ represent the statement state; then the steering wheel rotation angle ratio fuzzy inference rule is calculated as follows: If(η _A1 Δy _g , η _B1 △(△y _g ))is A ₁ ×B ₁ ,then u _δ is C ₁ ; among them, Where the statement state is: positive (PB), medium (PM), positive (PS), zero (ZE), negative (NS), negative (NM), negative (NB), its attribution function graph As shown in the fourth figure, the fuzzy control rule table is shown in Table 1.

The fuzzy inference rule of throttle and brake ratio is: If η _A2 △y _g =A ₂ and η _B2 △(△y _g )=B ₂ , then u _OB =C ₂ ; where △(△y _g )=△y _g (k)-Δy _g (k-1), Δy _g (k) represents the current data, Δy _g (k-1) represents the previous data; parameters η _A2 and η _B2 are normalization factors, fuzzy numbers A ₂ , B ₂ , and C ₂ represent the state of the statement; the equation for the fuzzy inference rule of the throttle and the brake ratio is as follows: If(η _A2 Δy _g , η _B2 Δ(Δy _g )) is A ₂ ×B ₂ , then u _OB is C ₂ ; among them, Wherein, the statement states are: positive (PB), medium (PM), positive (PS), zero (ZE), negative (NS), negative (NM), negative (NB), which belong to The function diagram is shown in Figure 5, and the fuzzy control rule table is shown in Table 2.

Moreover, the steering wheel rotation angle proportional control output fuzzy variable defuzzification system uses the center of gravity to defuzzify, and its formula is:

Where η _C1 is the denormalization factor and u _δ is the steering wheel rotation angle ratio.

The throttle and brake ratio control output fuzzy variables are also defocused by the center of gravity. The formula is:

Among them, η _C2 is the denormalization factor, and u _OB is the output ratio of the throttle and the brake. If it is positive, it means stepping on the throttle. If it is negative, it means the hi-hat.

Please refer to the sixth figure for a flow chart of a preset path for automatically controlling the vehicle to switch to the right lane by the method of the present invention. When performing the conversion to the right lane preset path, the program is: program (1) The sensor on the car will first detect whether there is a car on the right side, if there is a car on the right side, it cannot turn right and return to the program (1) If there is no car on the right, enter the procedure (2); if the program (2) detects whether there is a car behind, if there is a car at the rear, enter the program (3), if there is no car at the rear, enter the program (5); Procedure (3) Measure the safety distance and speed of the vehicle and the rear vehicle, and then enter the program (4); the program (4) judges whether it is safe to switch to the right lane. If it is not safe, it cannot turn right and return to the program (1); Procedure (5); Procedure (5) Detect whether there is a car in front, if there is a car in front, enter the procedure (6), if there is no car at the rear, enter the procedure (8); Procedure (6) Measure the vehicle and the vehicle in front Safety distance and speed, then enter the program (7); program (7) to determine whether it is safe to switch to the right lane, if not safe, can not turn right and return to the program (a); if safely enter the program (eight); program (eight Set the parameters l ₁ , ρ ₁ , l _{c of the} preset path, and then enter the program (9); the program (9) performs lighting The right direction light of the vehicle.

Referring to the seventh figure, a flow chart for automatically controlling the preset path of the vehicle to the left lane in the method of the present invention. When performing the conversion to the left lane preset path, the program is: program (1) The sensor on the car will first detect whether there is a car on the left side, if there is a car on the left side, it cannot turn left and return to the program (1) If there is no car on the left, enter the procedure (2); if the program (2) detects whether there is a car behind, if there is a car at the rear, enter the program (3), if there is no car at the rear, enter the program (5); Procedure (3) Measure the safety distance and speed of the vehicle and the rear vehicle, and then enter the program (4); the program (4) judges whether it is safe to switch to the left lane. If it is not safe, it cannot turn left and return to the program (1); Procedure (5); Procedure (5) Detect whether there is a car in front, if there is a car in front, enter the procedure (6), if there is no car at the rear, enter the procedure (8); Procedure (6) Measure the vehicle and the vehicle in front Safety distance and speed, then enter the program (7); program (7) to determine whether it is safe to switch to the left lane, if not safe, can not turn left and return to the program (a); if safely enter the program (eight); program (eight Set the parameters l ₁ , ρ ₁ , l _{c of the} preset path, and then enter the program (9); the program (9) lights the vehicle Left direction light.

The above is only a part of the embodiments of the present invention, and is not intended to limit the present invention. It is intended to be included in the scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application, and have completely complied with the patent law. The regulations and requirements, the application for invention patents in accordance with the law, and the application for review, and the grant of patents, are truly sensible.

Claims (7)

An automatic control method for a vehicle switching lane includes the following steps: a lane environment determining step of determining whether a lane can be changed according to environment information detected by at least one sensor installed in a vehicle to the surrounding environment of the vehicle; The step of changing the lane preset path, when determining that the lane can be changed, is given a preset path of the lane change, so that the vehicle performs the lane switching according to the preset path; wherein the mathematical equation for changing to the right lane is: The mathematical equation for the change to the left lane is: Where x _g is the longitudinal position of the vehicle and y _g is the lateral position of the vehicle, Is the preset path, exp is an exponential function, l ₁ is a lane change lateral path distance parameter, ρ ₁ is a lane change bending parameter, l _c is a lane change longitudinal path distance parameter; lighting step is a step of changing lane departure notice light, according to Converting the preset path of the lane to illuminate the directional light of the corresponding side of the vehicle; continuously outputting the ratio of the steering wheel rotation angle and the ratio of the throttle to the brake, according to the current displacement state of the vehicle and the preset path of the lane change The error is fuzzy controlled to obtain the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable, and then the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable are defuzzified. The steering wheel rotation angle ratio and the throttle to brake ratio are obtained, and the vehicle corrects the steering wheel rotation angle and the throttle and brake output according to the obtained steering wheel rotation angle ratio and the throttle to brake ratio, so that the driving dynamics of the vehicle conform to the Preset path. The automatic control method for a vehicle switching lane according to claim 1, wherein the environmental information around the vehicle includes a lane image, a front vehicle distance, a distance from a vehicle on the left and/or right lane, and a left And/or the speed of the vehicle on the right lane. The automatic control method for a vehicle switching lane according to claim 1 or 2, wherein the sensor is one or more of a radar, an optical radar, a global positioning system (GPS), a camera, and a camera. The automatic control method for a vehicle switching lane according to claim 3, wherein the input of the fuzzy control is: The fuzzy inference rules are: If η _A1 △y _g =A ₁ and η _B1 △(△y _g )=B ₁ , then u _δ =C ₁ ;If η _A2 Δy _g =A ₂ and η _B2 △(△ y _g )=B ₂ , then u _OB =C ₂ ; where Δ(Δy _g )=Δy _g (k)−Δy _g (k-1); Δy _g (k) represents current data, Δy _g (k-1) represents the previous data; the parameters η _A1 , η _A2 and η _B1 , η _B2 are normalization factors, and the fuzzy numbers A ₁ , A ₂ , B ₁ , B ₂ , C ₁ , C ₂ represent Statement state; then the operation formula of the fuzzy inference rule is as follows: If(η _A1 Δy _g , η _B1 △(Δy _g ))is A ₁ ×B ₁ , then u _δ is C ₁ ; And If(η _A2 Δy _g , η _B2 Δ(Δy _g ))is A ₂ ×B ₂ , then u _OB is C ₂ wherein The statement states are: positive (PB), medium (PM), positive (PS), zero (ZE), negative (NS), negative (NM), negative (NB). The automatic control method for a vehicle switching lane according to the fourth aspect of the invention, wherein the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable defuzzification system adopt a center of gravity defuzzification , the formula is: Among them, η _C1 and η _C2 are denormalization factors, u _δ is the steering wheel rotation angle ratio, u _OB is the output ratio of throttle and brake, if it is positive, it means stepping on the throttle, if it is negative, it means pedaling. The automatic control method for a vehicle switching lane according to claim 1 or 2, wherein the input of the fuzzy control is: The fuzzy inference rules are: If η _A1 △y _g =A ₁ and η _B1 △(△y _g )=B ₁ , then u _δ =C ₁ ;If η _A2 Δy _g =A ₂ and η _B2 △(△ y _g )=B ₂ , then u _OB =C ₂ ; where Δ(Δy _g )=Δy _g (k)−Δy _g (k-1); Δy _g (k) represents current data, Δy _g (k-1) represents the previous data; the parameters η _A1 , η _A2 and η _B1 , η _B2 are normalization factors, and the fuzzy numbers A ₁ , A ₂ , B ₁ , B ₂ , C ₁ , C ₂ represent Statement state; then the operation formula of the fuzzy inference rule is as follows: If(η _A1 Δy _g , η _B1 △(Δy _g ))is A ₁ ×B ₁ , then u _δ is C ₁ ; And If(η _A2 Δy _g , η _B2 Δ(Δy _g ))is A ₂ ×B ₂ , then u _OB is C ₂ ; Wherein, the statement states are: positive (PB), medium (PM), positive (PS), zero (ZE), negative (NS), negative (NM), negative (NB). The automatic control method for a vehicle switching lane according to claim 6, wherein the steering wheel rotation angle proportional control output fuzzy variable and the throttle and braking ratio control output fuzzy variable defuzzification system adopt gravity center defuzzification , the formula is: Among them, η _C1 and η _C2 are denormalization factors, u _δ is the steering wheel rotation angle ratio, u _OB is the output ratio of throttle and brake, if it is positive, it means stepping on the throttle, if it is negative, it means pedaling.