A method and system for determining the maximum speed of a vehicle in a stake environment

Abstract

A kind of determination method and system of maximum value of speed under stake environment.The road control module sends road condition signal to vehicle dynamics module, and sends stake code, stake radius, stake X coordinate and stake Y coordinate signal to stake collision judging module;Control module sends steering signal to vehicle dynamics module, and sends brake control signal to test bench module;Test bench module sends wheel cylinder hydraulic signal to vehicle dynamics module;Vehicle dynamics module sends steering signal to test bench module, and sends vehicle mass center X coordinate, vehicle mass center Y coordinate, vehicle geometric length, vehicle geometric width and vehicle mass center side slip angle signal to stake collision judging module;Stake collision judging module sends stake collision identification, collision stake code, collision stake X coordinate and collision stake Y coordinate signal to speed iteration module;Maximum speed iteration module iterates speed value in a loop.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle dynamics control, in particular to a method and system for determining the maximum speed of a vehicle in a stake environment. BACKGROUND

[0002] With the development of automotive chassis electronic control system and automatic driving technology, more and more vehicles are equipped with vehicle dynamics control function (VDC for short). The VDC function controls the longitudinal and lateral dynamics of the vehicle, and can keep the vehicle attitude stable after the driving condition changes. The VDC function needs to be tested on a test bench to verify the performance of the chassis control. The test bench test includes: in the double moving line working condition with stakes, when the vehicle passes through the starting stake at a certain initial speed, braking is performed, the driver can turn the steering wheel during braking to correct the direction, so that the vehicle can follow the expected path as much as possible, and the maximum speed that the vehicle can reach without hitting the stake is calculated.

[0003] The existing test method is to convert the distance between the vehicle and the stake into the longitudinal and lateral offset of the vehicle relative to the expected path.

[0004] However, the existing test method has the problem that the distance between the vehicle and the stake involves the geometric length of the vehicle shape, so the longitudinal and lateral offset of the vehicle relative to the expected path can only approximately simulate the distance between the vehicle and the stake, and the hard simulation does not conform to the actual state of the test working condition. SUMMARY

[0005] The present application solves the problem that the existing test method involves the geometric length of the vehicle shape in the distance between the vehicle and the stake, so the longitudinal and lateral offset of the vehicle relative to the expected path can only approximately simulate the distance between the vehicle and the stake, and the hard simulation does not conform to the actual state of the test working condition.

[0006] The system for determining the maximum speed of a vehicle in a stake environment comprises a road control module, a control module, a test bench module, a vehicle dynamics module, a stake collision judgment module and a maximum speed iteration module.

[0007] The road control module sends road condition signals to the vehicle dynamics module, and sends stake code, stake radius, stake X coordinate and stake Y coordinate signals to the stake collision judgment module; the road condition includes flat working condition and double moving line working condition;

[0008] The control module sends steering signals to the vehicle dynamics module, and sends brake control signals to the test bench module;

[0009] The test bench module sends wheel cylinder hydraulic signals to the vehicle dynamics module;

[0010] The vehicle dynamics module sends a steering signal to the test bench module, and sends a vehicle mass center X coordinate, a vehicle mass center Y coordinate, a vehicle geometric length, a vehicle geometric width and a vehicle mass center side slip angle signal to the stake collision judgment module;

[0011] The stake collision judgment module sends a stake collision identification, a collision stake code, a collision stake X coordinate and a collision stake Y coordinate signal to the vehicle speed iteration module;

[0012] The maximum vehicle speed iteration module iterates a vehicle speed value in a loop.

[0013] Further, in an embodiment of the present application, the steering signal comprises a vehicle gear, a vehicle throttle opening, a vehicle steering wheel angle, four vehicle wheel speeds and a vehicle longitudinal acceleration.

[0014] The method for determining the maximum vehicle speed in a stake environment according to the present application is implemented by using any one of the systems for determining the maximum vehicle speed in a stake environment according to the present application, and comprises the following steps:

[0015] Step S1, a road control module sends a double moving line working condition to a vehicle dynamics module, the vehicle dynamics module sends a vehicle mass center X coordinate, a vehicle mass center Y coordinate, a vehicle geometric length, a vehicle geometric width and a vehicle mass center side slip angle signal to a stake collision judgment module, the stake collision judgment module judges whether a vehicle collides with its nearest stake, if not, calculates the distance between the vehicle and its nearest stake pair, and executes step S2, if a collision occurs, the stake collision judgment module outputs a stake collision identification as 1 and the corresponding information of the stake;

[0016] Step S2, after the control module sets the maximum required vehicle speed to half of the maximum vehicle speed, the maximum speed iteration module starts to iteratively loop the maximum required vehicle speed of the vehicle;

[0017] Step S3, the road control module switches the double moving line working condition to a straight working condition, and sends it to the vehicle dynamics module, the control module sets the vehicle gear to the forward gear, and accelerates the vehicle to the maximum required vehicle speed by setting the throttle opening;

[0018] Step S4, the road control module switches the straight working condition to the double moving line working condition, and sends it to the vehicle dynamics module, the control module sets the throttle opening to 0, and immediately applies a braking force to reduce the vehicle speed to 0;

[0019] Step S5, the control module sets the vehicle gear to neutral, and the maximum required vehicle speed of the next loop returns to step S2 for iteration, until the number of iterations reaches a specified number, the maximum speed iteration module stops iteration, and the maximum required vehicle speed of the current loop is taken as the maximum vehicle speed that can be reached in the double moving line working condition.

[0020] Further, in one embodiment of the present application, the stake collision judging module judges whether the vehicle collides with its nearest stake by two formulas, if both formulas are satisfied, the vehicle does not collide with the nearest stake, if any one of the two formulas is not established, the vehicle collides with the nearest stake.

[0021] Further, in one embodiment of the present application, the two formulas are:

[0022]

[0023]

[0024] In the formula, R1 is the upper stake radius, R2 is the lower stake radius, and L2 is the vehicle geometric width.

[0025] Further, in one embodiment of the present application, the distance between the vehicle and its nearest stake pair is calculated, specifically:

[0026] In the X-Y plane coordinate system, all X coordinates of the stakes in the double moving line working condition are listed, if both specified formulas are satisfied, the stake is the nearest stake to the vehicle, and the distances between the vehicle and the upper and lower stakes are calculated, if any one of the specified formulas is not established, the stake is not the nearest stake to the vehicle.

[0027] Further, in one embodiment of the present application, the two specified formulas are:

[0028] X i > X0 (i = 1, 2, …, 5, …);

[0029]

[0030] In the formula, X i is the X coordinate of all stakes in the double moving line working condition, X0 is the current vehicle mass center X coordinate, and L1 is the vehicle geometric length.

[0031] Further, in one embodiment of the present application, the formula for calculating the distance between the vehicle and the upper stake is:

[0032]

[0033]

[0034] L5 = L3 sin (α1-β);

[0035] In the formula, Y0 is the current vehicle mass center Y coordinate, X1 is the upper marker post X coordinate, Y1 is the upper marker post Y coordinate, β is the current vehicle mass center side slip angle, α1 is the included angle between the upper marker post center and the vehicle mass center connection line and the X axis, L3 is the length of the upper marker post center and the vehicle mass center connection line, and L5 is the shortest distance from the upper marker post center to the vehicle driving direction.

[0036] The distance calculation formula of the vehicle and the lower marker post is as follows:

[0037]

[0038]

[0039] L6=L4sin(α2+β);

[0040] In the formula, X1 is the lower marker post X coordinate, Y2 is the lower marker post Y coordinate, α2 is the included angle between the lower marker post center and the vehicle mass center connection line and the X axis, L4 is the length of the lower marker post center and the vehicle mass center connection line, and L6 is the shortest distance from the lower marker post center to the vehicle driving direction.

[0041] Further, in an embodiment of the present application, the calculation formula of the required maximum vehicle speed of the next cycle is as follows:

[0042]

[0043] In the formula, k is the cycle number, V1 is the maximum speed that the vehicle can reach, V2 is the required maximum vehicle speed, C is an adjustment coefficient, during the period of applying the braking force until the speed is reduced to 0, if the marker post collision monitoring module outputs 0, C is set to 1, and if the marker post collision monitoring module outputs 1, C is set to -1.

[0044] Further, in an embodiment of the present application, the specified number of times is 8.

[0045] The present application solves the problem that the distance between the vehicle and the marker post in the existing test method involves the geometric length of the vehicle shape, so that the longitudinal and lateral offset of the vehicle relative to the expected path can only be approximately simulated as the distance between the vehicle and the marker post, and the hard simulation does not conform to the actual state of the test working condition. The specific beneficial effects include:

[0046] The determination method of the maximum vehicle speed in the marker post environment can accurately calculate the distance between the vehicle and the marker post, and further judge whether the vehicle collides with the marker post, and more accurately reflects the real vehicle working condition. Through the interpolation calculation method, the maximum speed that the vehicle can reach without colliding with the marker post is determined with fewer test steps. BRIEF DESCRIPTION OF DRAWINGS

[0047] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0048] Figure 1 is a system for determining the maximum vehicle speed in a stake environment according to the specific embodiment;

[0049] Figure 2 is a graph of the closest stake pair for a vehicle according to the specific embodiment;

[0050] Figure 3 is a graph of a vehicle colliding with a stake according to the specific embodiment. DETAILED DESCRIPTION

[0051] Various embodiments of the present application will be described herein below, by way of example only, with reference to the accompanying drawings. The embodiments described herein are intended to be illustrative only and should not be construed as being limiting of the present application.

[0052] The system for determining the maximum vehicle speed in a stake environment according to the present embodiment includes a road control module, a control module, a test bench module, a vehicle dynamics module, a stake collision judgment module, and a maximum vehicle speed iteration module.

[0053] The road control module sends road condition signals to the vehicle dynamics module, and sends stake code, stake radius, stake X coordinate, and stake Y coordinate signals to the stake collision judgment module. The road conditions include flat conditions and double offset conditions.

[0054] The control module sends steering signals to the vehicle dynamics module, and sends brake control signals to the test bench module.

[0055] The test bench module sends wheel cylinder hydraulic signals to the vehicle dynamics module.

[0056] The vehicle dynamics module sends steering signals to the test bench module, and sends vehicle center of mass X coordinate, vehicle center of mass Y coordinate, vehicle geometric length, vehicle geometric width, and vehicle center of mass side slip angle signals to the stake collision judgment module.

[0057] The stake collision judgment module sends stake collision identification, collision stake code, collision stake X coordinate, and collision stake Y coordinate signals to the vehicle speed iteration module.

[0058] The maximum vehicle speed iteration module iterates vehicle speed values.

[0059] In the present embodiment, the steering signals include vehicle gear, vehicle throttle opening, vehicle steering wheel angle, vehicle four-wheel speed, and vehicle longitudinal acceleration.

[0060] The embodiment is based on a system for determining the maximum vehicle speed in a stake environment according to the application, combined with Figure 1 To better understand the embodiment, an actual embodiment is provided:

[0061] The VDC maximum vehicle speed calculation module includes a vehicle dynamics module, a road control module, a control module, a stake collision judgment module, a maximum vehicle speed iteration module, and a test bench module.

[0062] The road control module sends road condition signals to the vehicle dynamics module, and sends stake code, stake radius, stake X coordinate, and stake Y coordinate signals to the stake collision judgment module. The road condition signals include flat road and double offset road, and different road conditions are switched through a road condition switching signal.

[0063] The control module sends gear, throttle opening, and steering control mode signals to the vehicle dynamics module, and sends brake control signals to the test bench module to control the actuator cylinder in the test bench, push the booster push rod forward, simulate the operation of the driver stepping on the brake pedal, generate brake pressure, and send wheel cylinder hydraulic signals to the vehicle dynamics module through the pressure steering wheel sensor in the test bench module to realize vehicle braking. The steering control mode adopts closed-loop steering control, and the maximum steering angle is 400 degrees and the maximum steering wheel speed is 400 degrees / second.

[0064] The vehicle dynamics module sends gear, throttle opening, steering wheel angle, four wheel speeds, and longitudinal acceleration signals to the test bench module for use by the ESC sample in the test bench, and sends vehicle center of gravity X coordinate, vehicle center of gravity Y coordinate, vehicle geometric length, vehicle geometric width, and vehicle center of gravity side slip angle signals to the stake collision judgment module.

[0065] The stake collision judgment module sends stake collision identification, collision stake code, collision stake X coordinate, and collision stake Y coordinate signals to the maximum vehicle speed iteration module.

[0066] The method for determining the maximum vehicle speed in a stake environment according to the embodiment is implemented by using any of the systems for determining the maximum vehicle speed in a stake environment according to the above embodiments, and includes the following steps:

[0067] Step S1, the road control module sends the double off-line working condition to the vehicle dynamics module, the vehicle dynamics module sends the vehicle mass center X coordinate, the vehicle mass center Y coordinate, the vehicle geometric length, the vehicle geometric width and the vehicle mass center side slip angle signal to the stake collision judgment module, the stake collision judgment module judges whether the vehicle collides with its nearest stake, if not, the distance between the vehicle and its nearest stake pair is calculated, and step S2 is executed, if collision occurs, the stake collision judgment module outputs the stake collision identification as 1 and the corresponding information of the stake pair;

[0068] Step S2, after the control module sets the maximum speed required by the vehicle to half of the maximum speed of the vehicle, the maximum speed iteration module starts to iteratively calculate the maximum speed required by the vehicle;

[0069] Step S3, the road control module switches the double off-line working condition to the straight working condition and sends it to the vehicle dynamics module, the control module sets the vehicle gear to forward gear, and the throttle opening degree accelerates the vehicle to the maximum speed required by the vehicle;

[0070] Step S4, the road control module switches the straight working condition to the double off-line working condition and sends it to the vehicle dynamics module, the control module sets the throttle opening degree to 0 and immediately applies the brake force to reduce the vehicle speed to 0;

[0071] Step S5, the control module sets the vehicle gear to neutral, and the maximum speed required by the vehicle in the next cycle returns to step S2 for iteration until the number of iterations reaches the specified number, then the maximum speed required by the vehicle in the current cycle is taken as the maximum speed that can be reached in the double off-line working condition.

[0072] In this embodiment, the stake collision judgment module judges whether the vehicle collides with its nearest stake by two formulas, if both formulas are satisfied, the vehicle does not collide with the nearest stake, if any of the two formulas is not established, the vehicle collides with the nearest stake.

[0073] In this embodiment, the two formulas are:

[0074]

[0075]

[0076] In the formula, R1 is the upper stake radius, R2 is the lower stake radius, and L2 is the vehicle geometric width.

[0077] In this embodiment, the distance between the vehicle and its nearest stake pair is calculated as follows:

[0078] In the X-Y plane coordinate system, list all the X coordinates of the stakes in the double moving line working condition, if the two specified formulas are satisfied, the stake is the closest stake to the vehicle, and the distances between the vehicle and the upper and lower stakes are calculated, if any of the two specified formulas is not established, the stake is not the closest stake to the vehicle.

[0079] In the embodiment, the two specified formulas are:

[0080] X i X0(i=1, 2,..., 5,...);

[0081]

[0082] In the formula, X i is the X coordinate of all the stakes in the double moving line working condition, X0 is the X coordinate of the current vehicle center of mass, and L1 is the geometric length of the vehicle.

[0083] In the embodiment, the calculation formula of the distance between the vehicle and the upper stake is:

[0084]

[0085]

[0086] L5=L3sin(α1-β);

[0087] In the formula, Y0 is the Y coordinate of the current vehicle center of mass, X1 is the X coordinate of the upper stake, Y1 is the Y coordinate of the upper stake, β is the current vehicle center of mass side slip angle, α1 is the included angle between the line connecting the center of the upper stake and the vehicle center of mass and the X axis, L3 is the length of the line connecting the center of the upper stake and the vehicle center of mass, and L5 is the shortest distance from the center of the upper stake to the driving direction of the vehicle.

[0088] The calculation formula of the distance between the vehicle and the lower stake is:

[0089]

[0090]

[0091] L6=L4sin(α2+β);

[0092] In the formula, X1 is the X coordinate of the lower stake, Y2 is the Y coordinate of the lower stake, α2 is the included angle between the line connecting the center of the lower stake and the vehicle center of mass and the X axis, L4 is the length of the line connecting the center of the lower stake and the vehicle center of mass, and L6 is the shortest distance from the center of the lower stake to the driving direction of the vehicle.

[0093] In the embodiment, the calculation formula of the maximum vehicle speed required by the vehicle in the next cycle is:

[0094]

[0095] In the formula, k is the number of cycles, V1 is the maximum speed that the vehicle can reach, V2 is the maximum speed required by the vehicle, and C is the adjustment coefficient. During the period from applying braking force to the vehicle speed dropping to 0, if the marker collision monitoring module outputs 0, then C = 1; if the marker collision monitoring module outputs 1, then C = -1.

[0096] In this embodiment, the specified number of times is 8 times.

[0097] This embodiment, based on the method for determining the maximum vehicle speed under a marker environment described in this invention, provides a practical implementation method:

[0098] I. Method for calculating the distance between a vehicle and a marker:

[0099] 1) Identify the pair of markers closest to the current vehicle. In the XY plane coordinate system, list all markers (A1, A2, ..., A...) in the double lane-change scenario. 10 The X coordinates (X1, X2, ..., X5, ...) of a marker are considered closest to a vehicle if both of the following equations are satisfied; otherwise, the marker is not the closest to a vehicle. Figure 2 As shown;

[0100] X i >X0(1=1,2,…,5,…);

[0101]

[0102] Among them, X i X is the X coordinate of all markers in the double lane change condition, X0 is the X coordinate of the current vehicle's centroid, and L1 is the vehicle's geometric length.

[0103] 2) Assume that, after calculation, marker A1A2 is the marker pair closest to the current vehicle. In the XY plane coordinate system, the distance L5 between the vehicle and the upper marker (marker A1) is calculated as follows:

[0104]

[0105]

[0106] L5 = L3sin(α1-β);

[0107] Where Y0 is the current Y-coordinate of the vehicle's center of gravity, X1 is the X-coordinate of marker A1, β is the current vehicle's sideslip angle, α1 is the angle between the line connecting the center of marker A1 and the vehicle's center of gravity and the X-axis, L3 is the length of the line connecting the center of marker A1 and the vehicle's center of gravity, and L5 is the shortest distance from the center of marker A1 to the vehicle's direction of travel. Figure 3 As shown.

[0108] 3) The distance L6 between the vehicle and the A2 peg is calculated as follows:

[0109]

[0110]

[0111] L6 = L4 sin (a2 + b);

[0112] wherein X1 is the X coordinate of the A2 peg, Y2 is the Y coordinate of the A2 peg, a2 is the angle between the line connecting the center of the A2 peg and the mass center of the vehicle and the X axis, L4 is the length of the line connecting the center of the A2 peg and the mass center of the vehicle, and L6 is the shortest distance from the center of the A2 peg to the driving direction of the vehicle, as shown in Figure 3 .

[0113] 4) The method for determining whether the vehicle collides with the peg is as follows: if the following two formulas are both satisfied, the vehicle does not collide with the peg; if either of the following two formulas is not satisfied, the vehicle collides with the peg:

[0114]

[0115]

[0116] wherein R1 is the radius of the A1 peg, R2 is the radius of the A2 peg, and L2 is the geometric width of the vehicle.

[0117] 5) If the entire double-movement-line working condition is completed and the vehicle does not collide with any peg, the peg collision determination module outputs the peg collision identification as 0; if the vehicle collides with a peg, the peg collision determination module outputs the peg collision identification as 1, as well as the peg number and coordinates A i (X i , Y i ).

[0118] II. The method for determining the maximum speed of the vehicle is as follows:

[0119] 1) The maximum speed V1 that the vehicle can reach under the double-movement-line working condition is defined as 160 km / h, the maximum speed V2 required by the vehicle is set as V1 / 2, the total cycle is set as 8 times, and the adjustment coefficient C is set as 0.

[0120] 2) The cycle iteration is started, and the cycle number k is increased by 1.

[0121] 3) The current road condition is set as a flat condition, the gear is set as the forward gear (D gear), and the vehicle is accelerated at a certain throttle opening (e.g., 0.6) until the speed of the vehicle reaches the maximum speed V2(k) required by the vehicle.

[0122] 4) Set the accelerator to 0, switch the current road condition to double lane shift condition, and immediately apply brake force until the vehicle speed is 0, the maximum vehicle speed V2(k+1) required in the next cycle is calculated as follows:

[0123]

[0124] wherein k is the cycle number, V1 is the maximum speed that the vehicle can reach, V2 is the maximum speed required by the vehicle, and C is an adjustment coefficient. If the post collision monitoring module outputs 0, then C = 1 is set; if the post collision monitoring module outputs 1, then C = -1 is set.

[0125] 5) Set the gear to neutral (N), return to step 2) and continue iteration until the cycle number k = 8, then stop iteration. V2(k) in the current cycle is taken as the maximum speed that can be reached in the double lane shift condition.

[0126] The above describes in detail the method and system for determining the maximum speed of a vehicle in a post environment. The principles and implementation of the present application are described using specific examples. The above examples are used to help understand the method and core idea of the present application. For those skilled in the art, the specific implementation and application range can be changed according to the idea of the present application. In summary, the content of the present application should not be understood as a limitation.

Claims

1. A system for determining the maximum vehicle speed under a marker environment, characterized in that, The system includes a road control module, a control module, a test bench module, a vehicle dynamics module, a marker collision judgment module, and a maximum vehicle speed iteration module. The road control module sends road condition signals to the vehicle dynamics module, and sends the marker code, marker radius, marker X coordinate, and marker Y coordinate signals to the marker collision judgment module; the road conditions include straight road conditions and double lane change conditions; The control module sends manipulation signals to the vehicle dynamics module and braking control signals to the test bench module. The test bench module sends the wheel cylinder hydraulic signals to the vehicle dynamics module; The vehicle dynamics module sends the control signal to the test bench module, and sends the vehicle centroid X coordinate, vehicle centroid Y coordinate, vehicle geometric length, vehicle geometric width and vehicle centroid sideslip angle signals to the marker collision judgment module. The marker collision judgment module sends the marker collision identifier, the collision marker code, the collision marker X coordinate, and the collision marker Y coordinate signals to the vehicle speed iteration module. The maximum vehicle speed iteration module iterates the vehicle speed value cyclically.

2. The system for determining the maximum vehicle speed under a marker environment according to claim 1, characterized in that, The control signals include vehicle gear position, vehicle throttle opening, vehicle steering wheel angle, vehicle four wheel speeds, and vehicle longitudinal acceleration.

3. A method for determining the maximum vehicle speed under a marker environment, wherein the method is implemented using the system for determining the maximum vehicle speed under a marker environment as described in any one of claims 1-2, characterized in that, Includes the following steps: In step S1, the road control module sends the double lane change condition to the vehicle dynamics module. The vehicle dynamics module sends the vehicle's centroid X coordinate, vehicle's centroid Y coordinate, vehicle's geometric length, vehicle's geometric width, and vehicle's centroid sideslip angle signals to the marker collision judgment module. The marker collision judgment module determines whether the vehicle has collided with its nearest marker. If no collision has occurred, the distance between the vehicle and its nearest marker is calculated, and step S2 is executed. If a collision has occurred, the marker collision judgment module outputs a marker collision flag of 1 and the corresponding information of the marker. Step S2: After the control module sets the maximum speed required by the vehicle to half of the maximum speed of the vehicle, the maximum speed iteration module starts to iterate the maximum speed required by the vehicle. In step S3, the road control module switches the double lane change mode to the straight mode and sends it to the vehicle dynamics module. The control module sets the vehicle gear to forward and accelerates the vehicle to the maximum speed required by the throttle opening. In step S4, the road control module switches the straight driving condition to the double lane change driving condition and sends it to the vehicle dynamics module. The control module sets the throttle opening to 0 and immediately applies braking force to reduce the vehicle speed to 0. In step S5, the control module sets the vehicle gear to neutral. The maximum speed required by the vehicle in the next cycle returns to step S2 to continue iterating until the number of cycles reaches the specified number. At this point, the maximum speed iteration module stops iterating, and the maximum speed required by the vehicle in the current cycle is taken as the maximum speed that can be achieved in the double lane change condition.

4. The method for determining the maximum vehicle speed under a marker environment according to claim 3, characterized in that, The marker collision judgment module determines whether a vehicle has collided with its nearest marker by using two criteria. If both criteria are met, the vehicle has not collided with the nearest marker. If either criterion is not met, the vehicle has collided with the nearest marker.

5. The method for determining the maximum vehicle speed under a marker environment according to claim 4, characterized in that, The two equations are: ； ； In the formula, R1 is the radius of the upper marker, R2 is the radius of the lower marker, L2 is the geometric width of the vehicle, L5 is the shortest distance from the center of the upper marker to the direction of vehicle travel, and L6 is the shortest distance from the center of the lower marker to the direction of vehicle travel.

6. The method for determining the maximum vehicle speed under a marker environment according to claim 3, characterized in that, The calculation of the distance between the vehicle and its nearest marker pair is as follows: In the XY plane coordinate system, list the X coordinates of all markers in the double lane change condition. If both specified equations are satisfied at the same time, then the marker is the closest marker to the vehicle. Calculate the distances between the vehicle and the upper and lower markers respectively. If either of the two specified equations is not satisfied, then the marker is not the closest marker to the vehicle.

7. The method for determining the maximum vehicle speed under a marker environment according to claim 6, characterized in that, The two specified formulas are: ； ； In the formula, X i X is the X coordinate of all markers in the double lane change condition, X0 is the X coordinate of the current vehicle's centroid, and L1 is the vehicle's geometric length.

8. The method for determining the maximum vehicle speed under a marker environment according to claim 6, characterized in that, The formula for calculating the distance between the vehicle and the upper marker is: ； ； ； In the formula, Y0 is the Y coordinate of the current vehicle's center of gravity, X1 is the X coordinate of the upper marker, β is the side slip angle of the current vehicle's center of gravity, α1 is the angle between the line connecting the center of the upper marker and the vehicle's center of gravity and the X-axis, L3 is the length of the line connecting the center of the upper marker and the vehicle's center of gravity, and L5 is the shortest distance from the center of the upper marker to the vehicle's direction of travel. The formula for calculating the distance between the vehicle and the marker is: ； ； ； In the formula, X1 is the X coordinate of the subscript stake, Y2 is the Y coordinate of the subscript stake, α2 is the angle between the line connecting the center of the subscript stake and the vehicle's center of mass and the X-axis, L4 is the length of the line connecting the center of the subscript stake and the vehicle's center of mass, L6 is the shortest distance from the center of the subscript stake to the vehicle's direction of travel, and X0 is the current X coordinate of the vehicle's center of mass.

9. The method for determining the maximum vehicle speed under a marker environment according to claim 3, characterized in that, The formula for calculating the maximum speed required by the vehicle in the next cycle is: ； In the formula, k The number of loops. V 1 represents the maximum speed the vehicle can achieve. V 2 represents the maximum speed required for the vehicle. C To adjust the coefficient, if the marker collision monitoring module outputs 0 during the period from when braking force is applied until the vehicle speed drops to 0, then the setting is... If the stake collision monitoring module outputs 1, then set .

10. The method for determining the maximum vehicle speed under a marker environment according to claim 3, characterized in that, The specified number of times is 8.

Images