Intelligent speed control system and method for on- and off-ramp, computer storage medium, and vehicle

Abstract

The present invention provides an intelligent speed control system and method for entering and exiting a ramp, a computer storage medium, and a vehicle, comprising an acquisition module for acquiring vehicle and road surface parameters, a ramp recommended speed calculation module for calculating a ramp recommended speed, a first acceleration module for obtaining a first recommended acceleration speed value based on the vehicle and road surface parameters and the ramp recommended speed, a second acceleration module for obtaining a second recommended acceleration speed value based on the vehicle and road surface parameters and the first recommended acceleration speed value, and a control module for controlling vehicle acceleration. The present invention provides the driver with a more reasonable speed control scheme based on actual ramp road conditions. During the process of exiting the ramp, the vehicle accelerates quickly for the first time to reduce the speed difference between the vehicle and other vehicles, ensuring vehicle safety and reducing the risk of traffic accidents. A second acceleration is then performed, and the driver is free to drive.

Description

Technical Field

[0001] The present invention belongs to the technical field of assisted safe driving and intelligent traffic control, and specifically relates to an intelligent speed regulation system and method for entering and exiting a ramp, a computer storage medium, and a vehicle. Background Art

[0002] When driving on highways or expressways, drivers sometimes need to enter a ramp to change their route. Since ramps are curved, it is difficult for the vehicle to turn in time if the speed is too high. This situation also poses a challenge to the lateral grip of the tires. Once the road surface is slippery, it is easy to skid, causing the vehicle to collide with the roadbed on both sides of the ramp, which is dangerous. Therefore, it is necessary to maintain a specific speed when driving on the ramp. However, due to the high speed of vehicles on highways and expressways, which is generally higher than the specific speed for vehicles to safely pass through the ramp, in most cases, the vehicle needs to slow down before entering the ramp and accelerate again after exiting the ramp, which causes many problems.

[0003] If the driver decelerates too early before entering the ramp, the vehicle will need to drive for a longer time, resulting in a greater relative speed between the vehicle and other vehicles on the main road, greatly increasing the risk of a traffic accident. If the driver decelerates too late, the vehicle may accelerate too much during deceleration, resulting in a poor driving experience for the driver, and sudden deceleration can easily lead to rear-end collisions. Similarly, if the driver accelerates too early after exiting the ramp, driving safety cannot be guaranteed. If the driver accelerates too late, the speed difference between the vehicle and other vehicles will be too large, greatly increasing the risk of a traffic accident.

[0004] In summary, during driving, providing drivers with reasonable speed control solutions that ensure both driving safety and driving comfort for different ramps has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to solve the difficulties existing in the above-mentioned prior art and provide an intelligent speed regulation system, method, computer storage medium and vehicle for entering and exiting a ramp. The system aims to assist the driver in adjusting the speed of the vehicle before entering and exiting the ramp by means of lane number and navigation information, thereby ensuring that the vehicle passes through the ramp safely; and avoid sudden acceleration and deceleration before entering and exiting the ramp, thereby ensuring a comfortable driving process.

[0006] One of the objectives of the present invention is to provide an intelligent speed control system for on- and off-ramps, comprising:

[0007] Acquisition module, used to obtain vehicle and road parameters;

[0008] a ramp recommended speed calculation module, configured to receive the vehicle and road parameters and obtain a ramp recommended speed based on the vehicle and road parameters;

[0009] a first acceleration module, configured to receive the vehicle and road surface parameters and the ramp recommended speed, and obtain a first recommended acceleration speed value based on the vehicle and road surface parameters and the ramp recommended speed; or to receive the vehicle and road surface parameters and obtain the first recommended acceleration speed value based on the vehicle and road surface parameters;

[0010] a second acceleration module, configured to receive the vehicle and road parameters and the first recommended acceleration speed value, and obtain a second recommended acceleration speed value based on the vehicle and road parameters and the first recommended acceleration speed value;

[0011] The control module is configured to receive the first recommended acceleration speed value and the second recommended acceleration speed value and control vehicle acceleration.

[0012] In a preferred embodiment of the present invention, the vehicle and road parameters include but are not limited to the friction coefficient between the vehicle tires and the road surface, the local acceleration of gravity, the curvature radius of the ramp, the number of lanes, the current maximum speed limit of the main road, the current vehicle speed, the upper speed limit, and the lower speed limit.

[0013] In a preferred embodiment of the present invention, the ramp recommended speed calculation module obtains the ramp recommended speed using the following formula:

[0014]

[0015] In formula (1), v0 is the recommended ramp speed; N1 is the first conversion parameter; μ is the friction coefficient between the vehicle tire and the road surface; g is the local acceleration of gravity; and R is the curvature radius of the ramp.

[0016] In a preferred embodiment of the present invention, the first acceleration module obtains the first recommended acceleration speed value using the following formula:

[0017] v3=v0+K(v4-v0) Formula (3)

[0018] In formula (3), v3 is the first acceleration recommended speed value; v0 is the ramp recommended speed; K is the speed conversion parameter; and v4 is the current main road maximum speed limit.

[0019] In a preferred embodiment of the present invention, the second recommended acceleration speed value is 80-100% of the current main road maximum speed limit.

[0020] In a preferred embodiment of the present invention,

[0021] The control module is configured to receive the first recommended acceleration speed value and control the vehicle to accelerate the vehicle from the ramp recommended speed to the first recommended acceleration speed value within a first preset acceleration distance; and / or

[0022] The control module is configured to receive the second recommended acceleration speed value and control the vehicle to accelerate the vehicle from the first recommended acceleration speed value to the second recommended acceleration speed value within a second preset acceleration distance;

[0023] Preferably,

[0024] The first preset acceleration distance is 50 to 250 m; and / or

[0025] The second preset acceleration distance is 50 to 250 meters;

[0026] More preferably,

[0027] After the first acceleration module calculates the first recommended acceleration speed value, it calculates a first acceleration based on the ramp recommended speed, the first recommended acceleration speed value, and the first preset acceleration distance and sends the first acceleration to the control module; the control module controls the vehicle to accelerate at the first acceleration; and / or

[0028] After receiving the first recommended acceleration speed value, the vehicle and road parameters, the second acceleration module calculates a second acceleration based on the first recommended acceleration speed value, the vehicle and road parameters, and the second preset acceleration distance and sends the calculation to the control module; the control module controls the vehicle to accelerate at the second acceleration.

[0029] In a preferred embodiment of the present invention, the on-ramp and off-ramp intelligent speed regulation system further includes:

[0030] a first deceleration module, configured to receive the vehicle and road parameters and the ramp recommended speed, and obtain a first deceleration recommended speed value based on the vehicle and road parameters and the ramp recommended speed;

[0031] a second deceleration module, configured to receive the first recommended deceleration speed value and the ramp recommended speed, and obtain a second deceleration based on the first recommended deceleration speed value and the ramp recommended speed;

[0032] Preferably,

[0033] The control module is configured to receive the first recommended deceleration speed value and control the vehicle to decelerate from a current vehicle speed to the first recommended deceleration speed value within a first preset deceleration distance; and / or

[0034] The control module is configured to receive the second deceleration and control the vehicle to decelerate from the first recommended deceleration speed value to the ramp recommended speed within a second preset deceleration distance;

[0035] More preferably,

[0036] The first preset deceleration distance is 400-600m; and / or

[0037] The second preset deceleration distance is 200 to 300 meters.

[0038] In a preferred embodiment of the present invention, the first deceleration module obtains the first recommended deceleration speed value using the following formula:

[0039] v2=v1-N2(v1-v0) Formula (4)

[0040] In formula (4), v2 is the first deceleration recommended speed value; v1 is the current vehicle speed; N2 is the conversion parameter; v0 is the ramp recommended speed;

[0041] Preferably, the conversion parameter is set to a value of 0.3 to 0.5.

[0042] In a preferred embodiment of the present invention, the on-ramp and off-ramp intelligent speed regulation system further includes:

[0043] The judgment module is configured to take the smaller value between the ramp recommended speed and the vehicle speed lower limit as the optimized ramp recommended speed.

[0044] A second object of the present invention is to provide an intelligent speed control method for an on-ramp or off-ramp, which is implemented using the intelligent speed control system for an on-ramp or off-ramp described in the first object of the present invention and specifically includes the following steps:

[0045] S1: Obtain vehicle and road parameters;

[0046] S2: Get the recommended ramp speed based on vehicle and road parameters;

[0047] S3: When the vehicle reaches a preset acceleration position, obtaining a first recommended acceleration speed value based on the vehicle and road surface parameters, the ramp recommended speed, or based on the vehicle and road surface parameters; controlling the vehicle to accelerate from the ramp recommended speed to the first recommended acceleration speed value; and / or

[0048] When the vehicle accelerates to a first recommended acceleration speed value, obtaining a second recommended acceleration speed value based on the vehicle and road surface parameters and the first recommended acceleration speed value; controlling the vehicle to accelerate from the first recommended acceleration speed value to the second recommended acceleration speed value; and / or

[0049] When the vehicle reaches a preset deceleration position, obtaining a first recommended deceleration speed value based on the vehicle and road parameters and the ramp recommended speed; controlling the vehicle to decelerate from the current speed to the first recommended deceleration speed value; and / or

[0050] When the vehicle decelerates to the first recommended deceleration speed value, the vehicle is controlled to decelerate from the first recommended deceleration speed value to the ramp recommended speed.

[0051] A third object of the present invention is to provide a computer-readable storage medium, wherein the computer-readable storage medium stores at least one computer-executable program, and the at least one program includes the intelligent speed control system for entry and exit ramps described in one of the objects of the present invention.

[0052] A fourth object of the present invention is to provide a vehicle comprising the computer-readable storage medium described in the third object of the present invention.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. The intelligent speed control system for on- and off-ramp access in this invention provides drivers with a more reasonable speed control plan based on the actual ramp road conditions. During the off-ramp process, the vehicle accelerates quickly for the first time to reduce the speed difference between the vehicle and other vehicles, ensuring vehicle safety and reducing the risk of traffic accidents. A second acceleration is then performed, leaving the driver free to drive. Before entering the ramp, the vehicle decelerates slightly to avoid sudden deceleration and improve the driver's driving experience. Then, the vehicle decelerates more quickly, ultimately ensuring that the vehicle's speed equals the recommended speed upon entering the ramp, ensuring that the vehicle passes the ramp at a reasonable speed without causing danger and ensuring vehicle safety.

[0055] 2. The intelligent speed control system for on- and off-ramp entry and exit of the present invention combines the number of lanes, the current maximum speed limit on the main road, and the recommended ramp speed to provide a reasonable acceleration plan during the exit process. This prevents sudden acceleration while minimizing the speed difference with other vehicles as quickly as possible to ensure safety. Before entering the ramp, the system combines the recommended ramp speed with the current vehicle speed to provide a reasonable deceleration plan, instructing the driver to reduce the current speed to the recommended speed in a safe and reasonable manner before entering the ramp. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 Schematic diagram of the intelligent speed control system for on- and off-ramp of the present invention;

[0057] Figure 2 Schematic diagram of the intelligent speed regulation method for on- and off-ramp of the present invention;

[0058] Figure 3 A graph showing the relationship between vehicle speed and time before entering a ramp in the intelligent speed regulation method for on- and off-ramp traffic of the present invention;

[0059] Figure 4 This is a diagram showing the relationship between vehicle speed and time after exiting the ramp in the intelligent speed regulation method for on- and off-ramp according to the present invention. DETAILED DESCRIPTION

[0060] The present invention is further described in detail below with reference to the accompanying drawings:

[0061] Example 1

[0062] like Figure 1 As shown, the present invention provides an intelligent speed control system for on- and off-ramp, comprising an acquisition module, a ramp recommended speed calculation module, a first acceleration module, a second acceleration module, and a control module. The following will describe these five modules in detail.

[0063] Get Module , used to obtain vehicle and road parameters. Preferably, the vehicle and road parameters include but are not limited to the friction coefficient μ between the vehicle tires and the road surface, the local gravity acceleration g, the curvature radius R of the ramp, the number of lanes n, the current main road maximum speed limit value v4, the current vehicle speed v1, the upper speed limit, and the lower speed limit. More specifically, Get Module Used to obtain the friction coefficient μ between the vehicle tires and the road surface, the local acceleration of gravity g, the curvature radius R of the ramp, the number of lanes n, the current speed value v4 of the main road's maximum speed limit, the current vehicle speed v1, the upper speed limit, and the lower speed limit. Among them, the local acceleration of gravity g, the curvature radius R of the ramp, the friction coefficient μ between the vehicle tires and the road surface, the number of lanes n, the current speed value v4 of the main road's maximum speed limit, the upper speed limit, and the lower speed limit are all stored in the database, and the acquisition module can directly call these seven data. It should be noted that the friction coefficient μ between the vehicle tires and the road surface was obtained from the test during the previous experiment and was stored in the database after the test was completed. The current vehicle speed v1 is obtained through the vehicle speed sensor.

[0064] ramp Recommended speed calculation module , is communicatively connected to the acquisition module; the ramp recommended speed calculation module is used to receive the vehicle and road parameters, and obtain the ramp recommended speed v0 based on the vehicle and road parameters. Preferably, the ramp recommended speed calculation module is used to receive the friction coefficient μ between the vehicle tires and the road surface, the local acceleration of gravity g, and the curvature radius R of the ramp sent by the acquisition module, and calculate the ramp recommended speed v0 based on the friction coefficient μ between the vehicle tires and the road surface, the local acceleration of gravity g, and the curvature radius R of the ramp. It should be noted that the ramp recommended speed v0 is the recommended speed for the ramp about to enter. This is because different ramps correspond to different optimal speeds, and the specific value of the ramp recommended speed v0 is related to the curvature radius R of the ramp, the friction coefficient μ between the vehicle tires and the road surface, and the acceleration of gravity g.

[0065] Specifically, the calculation process of the ramp recommended speed calculation module is shown in formula (1):

[0066]

[0067] In formula (1), v0 is the recommended ramp speed; N1 is the first conversion parameter; μ is the friction coefficient between the vehicle tire and the road surface; g is the local acceleration of gravity; R is the curvature radius of the ramp. It should be noted that the "maximum speed" here refers to the maximum speed v at which the vehicle can turn without deviation, calculated based on the curvature radius R, the friction coefficient μ, and the acceleration of gravity g. max The specific calculation method is as follows and will not be repeated here.

[0068] The derivation process of formula (1) is as follows: first calculate the maximum static friction force f between the vehicle tire and the road surface, then assume that the vehicle's speed when passing the current ramp is v, calculate the centripetal force required at speed v, and then make this required centripetal force less than or equal to the maximum static friction force f. This completes the physical model for the vehicle to avoid the risk of sideslip when passing the ramp. The physical model for the vehicle to avoid the risk of sideslip when passing the ramp is shown in formula (2):

[0069]

[0070] In formula (2), μ is the friction coefficient between the vehicle tire and the road surface; m is the total mass of the vehicle (unit: kg); g is the local acceleration of gravity; f is the maximum static friction between the vehicle tire and the road surface; v (unit: m / s) is the vehicle speed when passing the current ramp; R is the curvature radius of the ramp.

[0071] In order to ensure that the friction between the vehicle tires and the road surface can provide the centripetal force for the vehicle to turn, the vehicle speed needs to be as low as possible and less than or equal to a certain value, which is the maximum speed v passing the ramp. max Theoretically, the maximum static friction force f between the vehicle tire and the road is equal to the centripetal force The maximum speed of the ramp can be calculated by formula (2). In the actual driving process, as long as the vehicle speed is less than the maximum speed v max , which can ensure the safe passage of vehicles in the ramp.

[0072] The maximum speed v is calculated in the present invention max After that, the ramp recommended speed v0 can be set according to the needs. However, in order to ensure the safe passage of vehicles, it is necessary to ensure that the ramp recommended speed v0 is strictly less than the maximum speed v max Therefore, the ramp recommended speed v0 is calculated according to formula (1) in the present invention; in some cases, N1 can be set to 0.9, that is, the ramp recommended speed v0 is set to 0.9 times the maximum speed v max It should be noted that N1 is set to 0.9 here for exemplary purposes only, and those skilled in the art may set it to other values ​​less than 1.0 as required.

[0073] It can be seen that in actual use, the ramp recommended speed calculation module only needs to receive the next ramp curvature radius R, the local gravity acceleration g, and the friction coefficient μ between the vehicle tire and the road surface sent by the acquisition module to calculate the ramp recommended speed.

[0074] The first acceleration module , is communicatively connected to the ramp recommended speed calculation module and the acquisition module; the first acceleration module is used to receive the vehicle and road parameters, the ramp recommended speed v0, and obtain a first acceleration recommended speed value v3 based on the vehicle and road parameters and the ramp recommended speed v0; or is used to receive the vehicle and road parameters and obtain the first acceleration recommended speed value v3 based on the vehicle and road parameters. Specifically, the first acceleration module is used to receive the ramp recommended speed v0 sent by the ramp recommended speed calculation module and the speed value v4 for the lane number n and the current main road maximum speed limit sent by the acquisition module, and calculate the first acceleration recommended speed value v3 for exiting the ramp based on the ramp recommended speed v0, the lane number n, and the current main road maximum speed limit v4, so as to achieve initial rapid acceleration and quickly reduce the speed difference between the vehicle and other vehicles after exiting the ramp, thereby reducing the risk of traffic accidents.

[0075] According to the driving habits of most drivers, vehicles traveling in a large number of lanes, n, tend to travel at higher speeds. When the number of lanes, n, is small, vehicles travel at a relatively slow, but still relatively high, speed. To more quickly reduce the speed difference between the vehicle and vehicles in other lanes, thereby reducing the risk of traffic accidents, the present invention takes the number of lanes, n, into account when setting the first recommended acceleration speed, v3, when the vehicle exits the ramp and merges onto the main road.

[0076] Specifically, the calculation process of the first acceleration module is shown in formula (3):

[0077] v3=v0+K(v4-v0) Formula (3)

[0078] In formula (3), v3 is the first recommended acceleration speed value; v0 is the recommended ramp speed; K is the speed conversion parameter; and v4 is the speed value of the current main road maximum speed limit. It should be noted that the speed conversion parameter K is directly related to the number of lanes n, and the corresponding relationship between the two is shown in Table 1. As can be seen from Table 1, in general, the number of lanes is 2, 3, 4, or greater than 4. According to the number of lanes n in Table 1, the speed conversion parameter K corresponding to the number of lanes n can be queried and substituted into formula (3). Combined with the recommended ramp speed v0 and the current main road maximum speed limit v4, the first recommended acceleration speed value v3 can be calculated.

[0079] Table 1 Conversion table of lane number n and speed conversion parameter K

[0080] Number of lanes n 2 3 >＝4 Speed ​​conversion parameter K 0.6 0.7 0.8

[0081] Second acceleration module , communicating with the first acceleration module and the acquisition module; the second acceleration module is configured to receive the vehicle and road parameters and the first recommended acceleration speed value v3, and to determine a second recommended acceleration speed value v5 based on the vehicle and road parameters and the first recommended acceleration speed value v3; the control module is configured to receive the first recommended acceleration speed value v3 and the second recommended acceleration speed value v5 and control vehicle acceleration. The second acceleration module is configured to receive the first recommended acceleration speed value v3 sent by the first acceleration module and the current main road maximum speed limit v4 sent by the acquisition module, and to calculate a second recommended acceleration speed value v5 for exiting the ramp based on the first recommended acceleration speed value v3 and the current main road maximum speed limit v4, so that after exiting the ramp and undergoing the first acceleration, the vehicle can perform a second acceleration and adjust the vehicle speed to a higher speed. It should be noted that the second recommended acceleration speed value v5 can be slightly less than the current main road maximum speed limit v4, or can be the speed desired by the driver. Preferably, the second recommended acceleration speed value v5 is 80-100% of the maximum speed limit v4. When the vehicle speed reaches the second recommended acceleration speed value v5, just maintain the current vehicle speed and drive at a constant speed.

[0082] Control Module , connected to the first acceleration module and the second acceleration module; the control module is configured to receive the first recommended acceleration speed value v3 and the second recommended acceleration speed value v5 and control vehicle acceleration. Specifically, the control module is configured to receive the first recommended acceleration speed value v3 sent by the first acceleration module and control the vehicle to accelerate from the ramp recommended speed v0 to the first recommended acceleration speed value v3 within a first preset acceleration distance. The control module is configured to receive the second recommended acceleration speed value v5 sent by the second acceleration module and control the vehicle to accelerate from the first recommended acceleration speed value v3 to the second recommended acceleration speed value v5 within a second preset acceleration distance.

[0083] It should be noted that when the vehicle reaches a preset acceleration position (i.e., exiting the ramp), the first acceleration module and the control module are triggered. The first acceleration module receives the ramp recommended speed v0, the number of lanes n, and the current main road maximum speed limit v4, calculates a first recommended acceleration speed v3, and sends it to the control module. The control module receives the first recommended acceleration speed v3 and controls the vehicle to accelerate from the ramp recommended speed v0 to the first recommended acceleration speed v3 within a first preset acceleration distance. When the vehicle accelerates to the first recommended acceleration speed v3, the second acceleration module and the control module are triggered. The second acceleration module receives the first recommended acceleration speed v3 and the current main road maximum speed limit v4, calculates a second recommended acceleration speed v5, and sends it to the control module. The control module receives the second recommended acceleration speed v5 and controls the vehicle to accelerate from the first recommended acceleration speed v3 to the second recommended acceleration speed v5 within a second preset acceleration distance. In addition, the present invention determines whether the vehicle has exited the ramp based on the map positioning information, that is, determines whether the vehicle has reached the preset acceleration position based on the map positioning information. This is a conventional method in the field and will not be repeated here.

[0084] Preferably, the first preset acceleration distance is 50 to 250 meters; and / or the second preset acceleration distance is 50 to 250 meters. For example, after exiting the ramp and starting to accelerate, the vehicle needs to accelerate from the ramp recommended speed v0 to the first acceleration recommended speed value v3 within 250 meters. After exiting the ramp and undergoing the first round of acceleration and then performing the second round of acceleration, the vehicle needs to accelerate from the first acceleration recommended speed value v3 to the second acceleration recommended speed value v5 within 250 meters.

[0085] Furthermore, after the first acceleration module calculates the first recommended acceleration speed value v3, it calculates a first acceleration a based on the ramp recommended speed v0, the first recommended acceleration speed value v3, and the first preset acceleration distance L, and sends the calculated first acceleration a to the control module. The control module controls the vehicle to accelerate at the first acceleration a, so that the vehicle accelerates from the ramp recommended speed v0 to the first recommended acceleration speed value v3 within the first preset acceleration distance L. The calculation process of the first acceleration a is shown in formula (5):

[0086]

[0087] In formula (5), v3 is the first recommended acceleration speed value; v0 is the recommended ramp speed; a is the first acceleration; t is the acceleration time; and L is the first preset acceleration distance.

[0088] Similarly, after the second acceleration module calculates and receives the first acceleration recommended speed value v3 and the current main road maximum speed limit speed value v4, it calculates the second acceleration based on the first acceleration recommended speed value v3, the current main road maximum speed limit speed value v4 and the second preset acceleration distance, and sends it to the control module. The control module controls the vehicle to accelerate at the second acceleration to achieve the vehicle accelerating from the first acceleration recommended speed value v3 to the second acceleration recommended speed value v5 within the second preset acceleration distance. In another preferred embodiment of the present invention, within the second preset distance, the acceleration is 0.4 to 0.8 m / s 2 , more preferably 0.6 m / s 2 , to further improve the driver's driving comfort.

[0089] In a preferred embodiment of the present invention, the on-ramp and off-ramp intelligent speed regulation system further includes a first deceleration module and a second deceleration module. The following describes in detail these two modules and their relationship with the acquisition module, the ramp recommended speed calculation module, the first acceleration module, the second acceleration module, and the control module.

[0090] The first reduction module , is communicatively connected to the ramp recommended speed calculation module and the acquisition module; the first deceleration module is configured to receive the vehicle and road surface parameters and the ramp recommended speed v0, and to obtain a first recommended deceleration speed value v2 based on the vehicle and road surface parameters and the ramp recommended speed v0. Specifically, the first deceleration module is configured to receive the ramp recommended speed v0 sent by the ramp recommended speed calculation module and the current vehicle speed v1 sent by the acquisition module, and to calculate a first recommended deceleration speed value v2 before entering the ramp based on the ramp recommended speed v0 and the current vehicle speed v1, thereby slightly decelerating the vehicle in advance to facilitate lane changes.

[0091] Specifically, the calculation process of the first deceleration module is shown in formula (4):

[0092] v2=v1-N2(v1-v0) Formula (4)

[0093] In formula (4), v2 is the first recommended deceleration speed value; v1 is the current vehicle speed; N2 is the conversion parameter; and v0 is the recommended ramp speed. Substituting the conversion parameter N2, the recommended ramp speed v0, and the current vehicle speed v1 into formula (4) yields the first recommended deceleration speed value v2. Preferably, the conversion parameter N2 is set between 0.3 and 0.5, preferably 0.4, to avoid excessive deceleration and further improve driver comfort.

[0094] The second deceleration module, is communicatively connected to the recommended speed calculation module and the first deceleration module; the second deceleration module is configured to receive the first recommended deceleration speed value v2 and the ramp recommended speed v0, and to derive a second deceleration rate based on the first recommended deceleration speed value v2 and the ramp recommended speed v0. Specifically, the second deceleration module is configured to receive the ramp recommended speed v0 sent by the recommended speed calculation module and the first recommended deceleration speed value v2 sent by the first deceleration module, and to derive a second deceleration rate for entering the ramp based on the first recommended deceleration speed value v2 and the ramp recommended speed v0. This allows the vehicle to decelerate more quickly as it approaches the ramp entrance, ultimately ensuring that the vehicle's speed upon entering the ramp is equal to the ramp recommended speed v0. When the vehicle speed reaches the ramp recommended speed v0, the vehicle maintains its current speed and travels at a constant speed.

[0095] The first deceleration module is communicatively coupled to the control module, the control module being configured to receive a first recommended deceleration speed value v2 sent by the first deceleration module and control the vehicle to decelerate from a current vehicle speed v1 to the first recommended deceleration speed value v2 within a first preset deceleration distance. The second deceleration module is communicatively coupled to the control module, the control module being configured to receive a second deceleration speed sent by the second deceleration module and control the vehicle to decelerate from the first recommended deceleration speed value v2 to the ramp recommended speed v0 within a second preset deceleration distance.

[0096] It should be noted that when the vehicle reaches a preset deceleration position (illustratively, the preset position is 1 km from the ramp entrance), the first deceleration module and the control module are triggered. The first deceleration module receives the ramp recommended speed v0 and the current vehicle speed v1, calculates a first recommended deceleration speed value v2, and sends it to the control module. The control module receives the first recommended deceleration speed value v2 and controls the vehicle to decelerate from the current speed v1 to the first recommended deceleration speed value v2 within the first preset deceleration distance. When the vehicle decelerates to the first recommended deceleration speed value v2, the second deceleration module and the control module are triggered. The second deceleration module receives the first recommended deceleration speed value v2 and the ramp recommended speed v0, calculates a second deceleration, and sends it to the control module. The control module receives the second deceleration and controls the vehicle to decelerate from the first recommended deceleration speed value v2 to the ramp recommended speed v0 within the second preset deceleration distance. In addition, the present invention determines whether the vehicle is about to enter the ramp based on map positioning information, that is, determines whether the vehicle has reached the preset deceleration position based on map positioning information. This is a conventional method in the art and will not be further described here.

[0097] Preferably, the first preset deceleration distance is 400-600 meters; and / or the second preset deceleration distance is 200-300 meters. For example, when the vehicle reaches the preset deceleration position and begins to decelerate, deceleration from the current vehicle speed v1 to the first recommended deceleration speed value v2 needs to be completed within 500 meters. When the vehicle decelerates to the first recommended deceleration speed value v2, the vehicle needs to decelerate from the first recommended deceleration speed value v2 to the ramp recommended speed v0 within 250 meters.

[0098] It should be noted that after the first deceleration module calculates the first recommended deceleration speed value v2, it calculates a first deceleration based on the current vehicle speed v1, the first recommended deceleration speed value v2, and the first preset deceleration distance L1. The calculation is sent to the control module, which controls the vehicle to decelerate at the first deceleration, so that the vehicle decelerates from the current vehicle speed v1 to the first recommended deceleration speed value v2 within the first preset deceleration distance. Similarly, after the second deceleration module receives the first recommended deceleration speed value v2 and the recommended ramp speed v0, it calculates a second deceleration based on the first recommended deceleration speed value v2, the recommended ramp speed v0, and the second preset deceleration distance. The calculation is sent to the control module, which controls the vehicle to decelerate at the second deceleration, so that the vehicle decelerates from the first recommended deceleration speed value v2 to the recommended ramp speed v0 within the second preset deceleration distance.

[0099] In a preferred embodiment of the present invention, the on-ramp and off-ramp intelligent speed control system further includes a judgment module connected to the acquisition module, the ramp recommended speed calculation module, the first acceleration module, and the first deceleration module; the judgment module is configured to take the smaller value of the ramp recommended speed v0 and the vehicle speed lower limit as the optimized ramp recommended speed. Specifically, the judgment module is configured to compare the ramp recommended speed v0 sent by the ramp recommended speed calculation module with the vehicle speed lower limit (obtained based on the number of lanes n and Table 2) sent by the acquisition module, and take the smaller one as the final optimized ramp recommended speed v0. 优 , sent to the first acceleration module and the first deceleration module. The subsequent first acceleration recommended speed value v3 and the first deceleration recommended speed value v2 are both based on the optimized ramp recommended speed v 优 Calculated as the recommended ramp speed v0.

[0100] Table 2 Number of lanes and upper and lower speed limits on urban roads

[0101]

[0102]

[0103] This speed regulation method, implemented in this embodiment, adjusts the vehicle speed to a lower level to ensure driving safety. This approach simplifies the driver's deceleration actions, reduces restrictions on the driver's actions in complex road conditions, and provides more room for the driver to maneuver in complex road conditions.

[0104] Example 2

[0105] like Figure 2 As shown, the present invention provides an intelligent speed regulation method for on- and off-ramp, comprising the following steps:

[0106] S1: Obtain vehicle and road parameters.

[0107] Specifically, the friction coefficient μ between the vehicle tires and the road surface, the local acceleration of gravity g, the curvature radius R of the ramp, the number of lanes n, the current speed value v4 of the maximum speed limit on the main road, and the current vehicle speed v1 are obtained. Among them, the local acceleration of gravity g, the curvature radius R of the ramp, the friction coefficient μ between the vehicle tires and the road surface, the number of lanes n, and the current speed value v4 of the maximum speed limit on the main road are all stored in the database, and the acquisition module can directly call these five data. It should be noted that the friction coefficient μ between the vehicle tires and the road surface was obtained from the test during the previous experiment and was stored in the database after the test was completed. The current vehicle speed v1 is obtained through the vehicle speed sensor.

[0108] S2: Based on vehicle and road parameters, get the recommended ramp speed v0 。

[0109] Specifically, the recommended ramp speed v0 is calculated based on the friction coefficient μ between the vehicle tire and the road surface, the local gravity acceleration g, and the ramp curvature radius R. Specifically, the calculation process of the ramp recommended speed calculation module is shown in formula (1):

[0110]

[0111] In formula (1), v0 is the recommended ramp speed; N1 is the first conversion parameter; μ is the friction coefficient between the vehicle tire and the road surface; g is the local acceleration of gravity; and R is the ramp's radius of curvature. The derivation of formula (1) has been explained in detail above and will not be repeated here.

[0112] S3: When the vehicle reaches a preset position or reaches a preset speed, any one of S31 to S34 is executed.

[0113] Therefore, step S3 includes:

[0114] S31: When the vehicle reaches a preset acceleration position, a first recommended acceleration speed value v3 is obtained based on the vehicle and road surface parameters, the ramp recommended speed v0, or based on the vehicle and road surface parameters; and the vehicle is controlled to accelerate from the ramp recommended speed v0 to the first recommended acceleration speed value v3.

[0115] Specifically, when the vehicle reaches the preset acceleration position, the first acceleration recommended speed value v3 for exiting the ramp is obtained based on the ramp recommended speed v0, the number of lanes n, and the current main road maximum speed limit v4. Within the first preset acceleration distance, the vehicle accelerates from the ramp recommended speed v0 to the first acceleration recommended speed value v3. Specifically, the calculation process of the first acceleration module is shown in formula (3):

[0116] v3=v0+K(v4-v0) Formula (3)

[0117] In formula (3), v3 is the first acceleration recommended speed value; v0 is the ramp recommended speed; K is the speed conversion parameter; and v4 is the current main road maximum speed limit.

[0118] S32: When the vehicle accelerates to the first recommended acceleration speed value v3, a second recommended acceleration speed value v5 is obtained based on the vehicle and road surface parameters and the first recommended acceleration speed value v3; and the vehicle is controlled to accelerate from the first recommended acceleration speed value v3 to the second recommended acceleration speed value v5.

[0119] Specifically, when the vehicle accelerates to the first recommended acceleration speed value v3, a second recommended acceleration speed value v5 for exiting the ramp is calculated based on the first recommended acceleration speed value v3 and the current main road maximum speed limit value v4. Within the second preset acceleration distance, the vehicle accelerates from the first recommended acceleration speed value v3 to the second recommended acceleration speed value v5. When the vehicle speed reaches the second recommended acceleration speed value v5, the current speed is maintained and the vehicle continues driving at a constant speed.

[0120] S33: When the vehicle reaches the preset deceleration position, a first deceleration recommended speed value v2 is obtained based on the vehicle and road parameters and the ramp recommended speed v0; and the vehicle is controlled to decelerate from the current speed v1 to the first deceleration recommended speed value v2.

[0121] When the vehicle reaches the preset deceleration position, the first recommended deceleration speed value v2 before entering the ramp is calculated based on the ramp recommended speed v0 and the current vehicle speed v1. Within the first preset deceleration distance, the vehicle decelerates from the current speed v1 to the first recommended deceleration speed value v2. Specifically, the calculation process of the first deceleration module is shown in formula (4):

[0122] v2=v1-N2(v1-v0) Formula (4)

[0123] In formula (4), v2 is the first recommended deceleration speed value; v1 is the current vehicle speed; N2 is the conversion parameter; and v0 is the recommended ramp speed. Substituting the conversion parameter N2, the recommended ramp speed v0, and the current vehicle speed v1 into formula (4), the first recommended deceleration speed value v2 can be calculated.

[0124] S34: When the vehicle decelerates to the first recommended deceleration speed value v2, the vehicle is controlled to decelerate from the first recommended deceleration speed value v2 to the ramp recommended speed v0.

[0125] When the vehicle decelerates to the first recommended deceleration speed value v2, a second deceleration for entering the ramp is determined based on the ramp recommended speed v0 and the ramp recommended speed v0. Within the second preset deceleration distance, the vehicle decelerates from the first recommended deceleration speed value v2 to the ramp recommended speed v0. When the vehicle speed reaches the ramp recommended speed v0, the current speed is maintained and the vehicle continues driving at a constant speed.

[0126] It should be noted that the numbering of steps S31 to S34 does not limit the execution order, and when the triggering condition of any one of the four steps is met, the corresponding instruction can be executed.

[0127] The following combination Figure 3 The acceleration method after exiting the ramp (ie, step S31 and step S32 ) is exemplarily described.

[0128] S31: When the vehicle exits the ramp (i.e., before time t4), the acquisition module obtains the lane number n of the current main road and the current main road maximum speed limit value v4. The first recommended acceleration speed value v3 is calculated using formula (3). Then, starting at time t4, the vehicle begins to accelerate rapidly over the next 50 to 250 meters until the vehicle speed reaches the first recommended acceleration speed value v3 at time t5.

[0129] S32: From time t5, the vehicle accelerates slowly within a distance of 50 to 250 meters until, at time t6, the vehicle speed reaches a speed slightly lower than the current main road maximum speed limit value v4 or the speed required by the driver, and maintains a constant speed.

[0130] The speed regulation process of S31 and S32 here can be summarized as follows: after exiting the ramp, the vehicle first accelerates quickly to reduce the speed difference between the vehicle and other vehicles, and then freely adjusts the vehicle speed according to the driver's needs or accelerates to a speed value v4 slightly lower than the current maximum speed limit of the main road.

[0131] The following combination Figure 4 The deceleration method before entering the ramp (ie, step S33 and step S34) is exemplified below: Assuming that the current vehicle speed v1 = 120 km / h, the ramp recommended speed v0 = 70 km / h is calculated according to steps S1 and S2.

[0132] S33: When the vehicle reaches a point 1 km from the ramp entrance, set at time t1, the current vehicle speed v1 detected by the vehicle speed sensor is 120 km / h. The ramp recommended speed v0 is obtained by the ramp recommended speed calculation module, which is 70 km / h. According to equation (4), v2 is calculated to be 100 km / h (N2 = 0.4). Then, starting at time t1, over the next 400 to 600 meters, the speed is reduced by 0.4 times the speed difference, so that at time t2, the vehicle speed is decelerated to the first recommended deceleration speed value v2 = 100 km / h. That is, at time t2, the vehicle speed is reduced to 100 km / h.

[0133] S34: From time t2, over the next 200 to 300 meters, until time t3, the vehicle speed is reduced to v0 = 70 km / h. After reducing the speed to v0 = 70 km / h, the vehicle maintains a constant speed of 70 km / h and drives through the ramp.

[0134] The speed regulation process in S33 and S34 can be summarized as follows: before entering the ramp, the vehicle is decelerated slightly in advance to facilitate lane changes; when the vehicle approaches the ramp entrance, it is decelerated more rapidly, ultimately making the vehicle's speed equal to the ramp's recommended speed v0 when entering the ramp, and then passing the ramp at a constant speed.

[0135] Example 3

[0136] Since the speed limit on urban roads is generally less than or equal to 80 km / h, the speed difference between vehicles is relatively small, generally ranging from 50 to 80 km / h. Furthermore, because urban roads are shorter and have greater traffic volume than highways, it is more difficult to instruct drivers to perform more complex speed control actions in urban areas due to the more complex road conditions. The present invention also provides a simplified intelligent speed control method for on- and off-ramps on urban roads.

[0137] When the vehicle exits the ramp, step S31 can be replaced by the following step: Based on the lane number n, a first recommended acceleration speed value v3 is obtained. Specifically, when the vehicle exits the ramp, the lane number n of the current main road is obtained. Based on the obtained lane number n and combined with Table 2, the corresponding upper speed limit is obtained and used as the first recommended acceleration speed value v3. The vehicle accelerates from the ramp recommended speed v0 to the first recommended acceleration speed value v3 within the first preset acceleration distance.

[0138] S32: A second recommended acceleration speed v5 for exiting the ramp is calculated based on the first recommended acceleration speed v3 and the current main road maximum speed limit v4. The vehicle accelerates from the first recommended acceleration speed v3 to the second recommended acceleration speed v5 within a second preset acceleration distance. When the vehicle speed reaches the second recommended acceleration speed v5, the current vehicle speed is maintained at a constant speed.

[0139] This embodiment's speed regulation method uses the average speed of vehicles traveling on the main road of each lane as the upper speed limit, and also uses this speed as the initial acceleration speed after exiting the ramp. This ensures that vehicles accelerate promptly and minimizes the speed difference with other vehicles. The lowest speed at which each lane can travel smoothly is used as the lower speed limit, ensuring that all vehicles can pass normally and reducing traffic congestion.

[0140] In a preferred embodiment of the present invention, when the vehicle is about to enter the ramp, step S33 may further include the following steps: obtaining a lower speed limit based on the number of lanes n; obtaining an optimized ramp recommended speed v based on the lower speed limit and the ramp recommended speed v0; 优 Specifically, before the vehicle enters the ramp on the urban road section, the ramp recommended speed v0 is calculated using the method in step S2 (N1 is set to 0.8). The number of lanes n on the main road after the ramp is obtained; based on the obtained number of lanes n, the corresponding lower speed limit is obtained by querying Table 2. Compare the ramp recommended speed v0 with the speed lower limit, and take the smaller one as the final optimized ramp recommended speed v 优 Based on the optimized ramp recommended speed v 优 The first recommended deceleration speed value v2 before entering the ramp is calculated from the current vehicle speed v1. The vehicle decelerates from the current vehicle speed v1 to the first recommended deceleration speed value v2 within the first preset deceleration distance.

[0141] S34: Recommended speed v based on optimized ramp 优 , the ramp recommended speed v0 is used to obtain the second deceleration for entering the ramp. Within the second preset deceleration distance, the vehicle decelerates from the first deceleration recommended speed value v2 to the ramp recommended speed v0. When the vehicle speed reaches the optimized ramp recommended speed v 优 Just keep the current speed and drive at a constant speed.

[0142] Because the curvature radius of urban ramps is relatively small, the speed regulation method of this embodiment adjusts the vehicle speed even lower to ensure driving safety. This approach simplifies the driver's deceleration action, reduces restrictions on the driver's actions in complex road conditions, and provides more maneuverability for the driver to handle complex road conditions.

[0143] The present invention also relates to a computer-readable storage medium storing at least one computer-executable program, wherein the at least one program includes the aforementioned intelligent speed control system for on- and off-ramps. The present invention also relates to a vehicle including the computer-readable storage medium.

[0144] The above technical solution is only one embodiment of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. An intelligent speed control system for entry and exit ramps, characterized in that: include: Acquisition module, used to obtain vehicle and road parameters; a ramp recommended speed calculation module, configured to receive the vehicle and road parameters and obtain a ramp recommended speed based on the vehicle and road parameters, wherein the ramp recommended speed is a ramp recommended speed for an upcoming entry; Among them, the recommended speed of the ramp is: In formula (1), v0 is the recommended ramp speed; N1 is the first conversion parameter, N1 is less than 1; μ is the friction coefficient between the vehicle tire and the road surface; g is the local gravity acceleration; R is the curvature radius of the ramp; A first acceleration module is configured to receive the lane number, the current maximum speed limit of the main road, and the ramp recommended speed, and obtain a first acceleration recommended speed value based on the lane number, the current maximum speed limit of the main road, and the ramp recommended speed; Among them, the recommended speed value for the first acceleration is: v3=v0+K(v4-v0) Formula (3) In formula (3), v3 is the first acceleration recommended speed value; v0 is the ramp recommended speed; K is the speed conversion parameter, which is directly related to the number of lanes; v4 is the current main road maximum speed limit value; a second acceleration module, configured to receive the first recommended acceleration speed value sent by the first acceleration module and the speed value of the current main road maximum speed limit sent by the acquisition module, and calculate a second recommended acceleration speed value for exiting the ramp based on the first recommended acceleration speed value and the speed value of the current main road maximum speed limit; A control module is configured to receive the first recommended acceleration speed value and the second recommended acceleration speed value and control vehicle acceleration; the control module is configured to receive the first recommended acceleration speed value and control the vehicle to accelerate from the ramp recommended speed to the first recommended acceleration speed value within a first preset acceleration distance; and the control module is configured to receive the second recommended acceleration speed value and control the vehicle to accelerate from the first recommended acceleration speed value to the second recommended acceleration speed value within a second preset acceleration distance; the first preset acceleration distance is 50 to 250 meters; and the second preset acceleration distance is 50 to 250 meters.

2. The system according to claim 1, wherein: The vehicle and road parameters include but are not limited to the friction coefficient between the vehicle tires and the road surface, the local acceleration of gravity, the curvature radius of the ramp, the number of lanes, the current maximum speed limit of the main road, the current vehicle speed, the upper speed limit, and the lower speed limit.

3. The system according to claim 2, characterized in that After the first acceleration module calculates the first recommended acceleration speed value, the first acceleration module calculates a first acceleration based on the ramp recommended speed, the first recommended acceleration speed value, and the first preset acceleration distance and sends the first acceleration to the control module; The control module controls the vehicle to accelerate at the first acceleration; and / or After receiving the first recommended acceleration speed value, the vehicle and road parameters, the second acceleration module calculates a second acceleration based on the first recommended acceleration speed value, the vehicle and road parameters, and the second preset acceleration distance and sends the second acceleration to the control module; The control module controls the vehicle to accelerate at the second acceleration.

4. The system according to claim 3, characterized in that The intelligent speed control system for the entry and exit ramps further includes: a first deceleration module, configured to receive the vehicle and road parameters and the ramp recommended speed, and obtain a first deceleration recommended speed value based on the vehicle and road parameters and the ramp recommended speed; a second deceleration module, configured to receive the first recommended deceleration speed value and the ramp recommended speed, and obtain a second deceleration based on the first recommended deceleration speed value and the ramp recommended speed; The control module is configured to receive the first recommended deceleration speed value and control the vehicle to decelerate from a current vehicle speed to the first recommended deceleration speed value within a first preset deceleration distance; and / or The control module is configured to receive the second deceleration and control the vehicle to decelerate from the first recommended deceleration speed value to the ramp recommended speed within a second preset deceleration distance; The first preset deceleration distance is 400-600m; and / or The second preset deceleration distance is 200 to 300 meters.

5. The system according to claim 4, characterized in that The first deceleration module obtains the first deceleration recommended speed value using the following formula: v2=v1-N2(v1-v0) Formula (4) In formula (4), v2 is the first deceleration recommended speed value; v1 is the current vehicle speed; N2 is the conversion parameter; v0 is the ramp recommended speed; the conversion parameter value is 0.3 to 0.

5.

6. The system according to claim 5, characterized in that The intelligent speed control system for the entry and exit ramps further includes: The judgment module is configured to take the smaller value between the ramp recommended speed and the vehicle speed lower limit as the optimized ramp recommended speed.

7. An intelligent speed regulation method for an on-ramp or off-ramp, based on the intelligent speed regulation system for an on-ramp or off-ramp according to any one of claims 1 to 6, characterized in that: include: S1: Obtain vehicle and road parameters; S2: Get the recommended ramp speed based on vehicle and road parameters; S3: When the vehicle reaches a preset acceleration position, obtaining a first recommended acceleration speed value based on the vehicle and road surface parameters, the ramp recommended speed, or based on the vehicle and road surface parameters; and controlling the vehicle to accelerate from the ramp recommended speed to the first recommended acceleration speed value; and / or When the vehicle accelerates to a first recommended acceleration speed value, obtaining a second recommended acceleration speed value based on the vehicle and road surface parameters and the first recommended acceleration speed value; and controlling the vehicle to accelerate from the first recommended acceleration speed value to the second recommended acceleration speed value; and / or When the vehicle reaches a preset deceleration position, a first recommended deceleration speed value is obtained based on the vehicle and road parameters and the ramp recommended speed; and the vehicle is controlled to decelerate from the current speed to the first recommended deceleration speed value. and / or When the vehicle decelerates to the first recommended deceleration speed value, the vehicle is controlled to decelerate from the first recommended deceleration speed value to the ramp recommended speed.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores at least one computer-executable program, and the at least one program includes the intelligent speed regulation system for on- and off-ramp according to any one of claims 1 to 6.

9. A vehicle, characterized in that: Comprising the computer-readable storage medium of claim 8.

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