A ramp nonlinear widening design method and system
By constructing an articulated train model, the nonlinear widening values of the outer and inner sides of the ramp were determined, which solved the problems of blind spots and poor track in traditional ramp design, reduced the risk of conflict between the articulated train and the guardrail, and improved traffic safety.
Patent Information
- Application Number
- CN202610279767.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-09
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional ramp designs neglect the blind spots and trajectory differences of heavy-duty, long-wheelbase articulated trains during turns, causing drivers to be unable to detect obstacles in time and increasing the risk of traffic accidents.
By constructing an articulated train model that considers the blind spots of semi-trailer tractors and the maximum cross-track difference, the nonlinear widening values of the outer and inner sides of the ramp are determined to provide sufficient turning space and reduce the risk of conflict with the guardrail.
This effectively reduces the conflict between articulated trains and the guardrails on both sides of the ramps, reduces traffic safety hazards, and improves the service level of interchanges.
Smart Images
Figure CN122174324A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of road design technology, and in particular to a method and system for nonlinear widening design of ramps. Background Technology
[0002] With the increasing density of highway networks and the rapid development of the logistics and transportation industry, the proportion of large-tonnage, long-wheelbase articulated trains in highway traffic flow has risen significantly. However, conventional interchange ramps are usually designed with small-radius curves due to terrain and cost constraints, while articulated trains, consisting of a tractor and trailer articulated together, have a long body and poor turning flexibility. Especially during small-radius turns, the tall front structure directly obstructs the driver's view of the road conditions below and to the sides, creating a significant near-ground blind spot. In addition, the long wheelbase causes a significant inward deviation of the wheel track, and the combination of blind spot and track expansion often leads to scraping or collisions between vehicles and the inner and outer guardrails of the ramp, causing traffic congestion and safety hazards. Traditional ramp designs focus on lane width and curve radius settings, but often neglect the dynamic behavior of vehicles during turning, especially the driver's blind spot and the maximum cross-track difference of semi-trailer tractors. These factors not only affect the driver's judgment but may also prevent the driver from noticing obstacles in the driving path in time, thus increasing the risk of accidents. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a nonlinear widening design method and system for ramps, which effectively reduces the conflict between articulated trains and the inner and outer guardrails of the ramps, thereby effectively reducing traffic safety hazards in the ramp area.
[0004] The first aspect of this invention provides a method for nonlinear widening design of ramps, comprising the following steps: Collect semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, driver's viewpoint parameters, ramp geometric parameters, and ramp guardrail design parameters; Based on the vehicle parameters of the semi-trailer tractor and the driver's viewpoint parameters, an articulated train model that takes into account the blind spots of the semi-trailer tractor is constructed. Based on the semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, and ramp geometric design parameters, an articulated train motion trajectory model considering the maximum cross wheel track difference is constructed. Based on the articulated train model that takes into account the blind spot of the semi-trailer tractor, the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot is determined. Based on the articulated train motion trajectory model considering the maximum cross wheel track difference, the nonlinear widening value of the inner side of the ramp curve under the influence of the track difference is determined.
[0005] Optional parameters for semi-trailer tractor vehicles include: wheelbase. Front axle track Distance from rear axle to the center of the lead pin The distance between the left and right A-pillars of the driver's cab D f The distance of the left-side window of the driver's cab D l The distance of the right-side window of the driver's cab D r The distance between the two boundaries of the left A-pillar of the driver's cab D a and the distance between the two boundaries of the right A-pillar of the driver's cab. D b Semi-trailer vehicle parameters include the longitudinal distance from the lead pin to the rear axle of the semi-trailer. Driver's viewpoint parameters include: the distance from the driver's eye point to the right frame of the left side A. L lr Distance to the left edge of the right A-pillar L rl Distance to the left edge of the left side window L lol Distance to the right frame of the left side window L lor Distance to the left edge of the right-side window L rol Distance to the right side frame of the right-side window L ror Distance to the left side of the A-pillar L ll Distance to the right side of the A-pillar L rr Ramp geometry parameters include ramp radius. and lane width W l The parameters for ramp guardrails include the distance between the inner guardrail of the curve and the inner lane edge. L nh The distance between the outer guardrail of the curve and the outer lane edge line L wh .
[0006] Optionally, constructing an articulated train model that takes into account the blind spots of the semi-trailer tractor includes: Based on the driver's viewpoint parameters, the following are obtained: the forward semi-blind zone determined by the left and right A-pillar boundaries, the left semi-blind zone determined by the left window boundary, the right semi-blind zone determined by the right window boundary, and the A-pillar complete blind zone determined by the left and right A-pillar boundaries. Each blind spot is treated as a virtual extension of the vehicle body and superimposed onto the physical outline of the vehicle body. The generalized geometric boundary of the articulated train, including the blind spots, is reconstructed to obtain the geometric model of the articulated train.
[0007] Optionally, constructing a motion trajectory model for an articulated train that considers the maximum crossover wheel track difference includes: Based on the vehicle parameters of the semi-trailer tractor and the geometric design parameters of the ramp, the radius of the wheel track when the left front wheel of the semi-trailer tractor travels along the edge of the outer lane line is obtained. Using the radius of the left front wheel track as a guiding reference, the radius of the right rear wheel track of the semi-trailer is obtained based on the vehicle parameters and kinematic geometry of the semi-trailer. Based on the wheel track radius of the left front wheel and the wheel track radius of the right rear wheel, the articulation angle between the tractor and the semi-trailer and the maximum cross wheel track difference are determined, thus obtaining the motion trajectory model of the articulated train.
[0008] Optionally, determining the nonlinear widening value of the outer side of the ramp curve under the influence of blind spots includes: Obtain the maximum boundary distance of each blind spot; Select the corresponding maximum blind spot boundary distance based on the turning direction; Determine whether the outer guardrail of the curve is within the boundary of the maximum blind spot. If it is within the blind spot, the single-point widening value is obtained by combining the difference between the maximum blind spot boundary distance and the distance from the guardrail to the lane edge line with the safety factor.
[0009] Optionally, determining the nonlinear widening value of the inner side of the ramp curve under the influence of trajectory difference includes: Obtain the trajectory difference between the radius of the left front wheel track of the semi-trailer tractor and the radius of the right rear wheel track of the semi-trailer; Determine whether the guardrail on the inside of the curve will conflict with the movement trajectory of the semi-trailer; If a conflict occurs, the single-point widening value is obtained based on the trajectory difference, lane width, and distance from the guardrail to the inner lane edge, combined with the safety factor.
[0010] Optionally, the safety factor is a value adjusted according to the actual engineering situation, used to round or enlarge the widening value to ensure the safety and practicality of the design.
[0011] A second aspect of the present invention provides a ramp nonlinear widening design system, comprising: The parameter acquisition module is used to collect semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, driver's viewpoint parameters, ramp geometric parameters, and ramp guardrail design parameters. The blind spot modeling module is used to construct an articulated train model that takes into account the blind spots of the semi-trailer tractor based on the vehicle parameters of the semi-trailer tractor and the driver's viewpoint parameters. The motion trajectory modeling module is used to construct a motion trajectory model of the articulated train that takes into account the maximum cross wheel track difference, based on the semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, and ramp geometric design parameters. The outer widening calculation module is used to determine the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot, based on the articulated train model that takes into account the blind spot of the semi-trailer tractor. The inner widening calculation module is used to determine the nonlinear widening value of the inner side of the ramp curve under the influence of the trajectory difference, based on the articulated train motion trajectory model that takes into account the maximum cross wheel track difference.
[0012] Optionally, the blind spot modeling module is used for: Obtain the geometric range of the semi-blind spots in the frontal field of view, the semi-blind spots in the left side of the field of view, the semi-blind spots in the right side of the field of view, and the complete blind spot in the A-pillar field of view; Each blind spot is superimposed onto the vehicle body outline to generate a generalized geometric boundary model of the articulated train.
[0013] Optionally, the motion trajectory modeling module is used for: Obtain the radius of the wheel track of the left front wheel of the semi-trailer tractor under the most unfavorable working conditions; Calculate the wheel track radius and articulation angle of the right rear wheel of the semi-trailer based on vehicle kinematics; The maximum difference in the cross track distance is obtained based on the radius of the left front wheel and the right rear wheel tracks.
[0014] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art: This invention provides a method and system for nonlinear widening of ramps. It utilizes an articulated train model that considers the blind spots of semi-trailer tractors to provide a visual field guarantee for determining the geometric boundary of the nonlinear widening on the outer side of the ramp. It also uses an articulated train trajectory model that considers the maximum cross-track difference to provide maximum sweep path data for calculating the trajectory width of the nonlinear widening on the inner side of the ramp. By employing nonlinear widening design methods considering both the blind spots on the outer side of ramp curves and the maximum cross-track difference on the inner side of ramp curves, the invention performs nonlinear widening design of the ramp, providing sufficient turning space for articulated trains. This invention effectively reduces the conflict between articulated trains and the guardrails on both sides of the ramp, significantly reducing traffic safety hazards in the ramp area and greatly improving the service level of interchanges. Furthermore, it is easy to operate, highly practical, and can be widely applied in engineering practice. Attached Figure Description
[0015] Figure 1 A flowchart of a nonlinear widening design method for ramps provided in an embodiment of the present invention; Figure 2 A schematic diagram of an articulated train model considering the blind spots of a semi-trailer tractor provided in an embodiment of the present invention; Figure 3The articulated train motion trajectory model considering the maximum cross wheel track difference is provided for embodiments of the present invention.
[0016] Explanation of reference numerals in the attached figures: 1. Semi-trailer tractor; 2. Articulated structure; 3. Semi-trailer; 4. Front side window; 5. Right side window; 6. Left side window; 7. Left and right A-pillars; 8. Semi-blind spot in front; 9. Semi-blind spot on the right; 10. Semi-blind spot on the left; 11. Complete blind spot of both A-pillars on the left and right; 12. Trajectory of the right front wheel of the tractor; 13. Maximum difference in track width between the two wheels; 14. Driving lane; 15. Outer guardrail of the ramp; 16. Trajectory of the right rear wheel of the semi-trailer; 17. Inner wheel difference area; 18. Trajectory of the left front wheel of the tractor; 19. Inner guardrail of the ramp. Detailed Implementation
[0017] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.
[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0019] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments clear and concise, detailed descriptions of known functions and components may be omitted. When any component of an embodiment of the present invention appears in more than one drawing, the component may be represented by the same reference numerals in each drawing.
[0020] like Figure 1 As shown, the first embodiment of the present invention provides a method for nonlinear widening of ramps, including the following steps: Collect vehicle parameters for semi-trailer tractor 1, semi-trailer 3, driver's viewpoint parameters, ramp geometry parameters, and ramp guardrail design parameters. Based on the vehicle parameters of semi-trailer tractor 1 and the driver's viewpoint parameters, an articulated train model considering the blind spots of semi-trailer tractor 1 is constructed. Based on the vehicle parameters of semi-trailer tractor 1, semi-trailer 3 and ramp geometric design parameters, a motion trajectory model of the articulated train considering the maximum cross wheel track difference 13 is constructed. Based on the articulated train model that takes into account the blind spot of one semi-trailer tractor, the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot is determined. Based on the articulated train motion trajectory model considering the maximum cross wheel track difference of 13, the nonlinear widening value of the inner side of the ramp curve under the influence of the track difference is determined.
[0021] This invention provides a nonlinear widening design method for ramps. It uses an articulated train model considering the blind spot of a semi-trailer tractor to provide a visual field guarantee for determining the geometric boundary of the nonlinear widening on the outer side of the ramp. It utilizes an articulated train trajectory model considering the maximum cross-track difference 13 to provide maximum sweep path data for calculating the trajectory width of the nonlinear widening on the inner side of the ramp. The method employs nonlinear widening design methods considering both the blind spot of the ramp's outer side and the maximum cross-track difference 13 on the inner side of the ramp curve to perform nonlinear widening design, providing sufficient turning space for the articulated train. This invention considers the blind spot of the articulated train and the maximum cross-track difference 13 to perform nonlinear widening design on the ramp, avoiding insufficient collision prevention for the articulated train in the inner wheel difference area 17, effectively reducing the degree of conflict between the articulated train and the inner and outer guardrails of the ramp, and effectively reducing traffic safety hazards in the ramp area. This is of great significance for improving the service level of interchanges. Furthermore, it is easy to operate, highly practical, and can be widely applied in engineering practice.
[0022] Specifically, the parameters for one semi-trailer tractor include: wheelbase Front axle track Distance from rear axle to the center of the lead pin The distance between the left and right A-pillars of the driver's cab D f The distance of 6 widths from the left-side window of the driver's cab D l The distance of 5 widths from the right-side window of the driver's cab D r The distance between the two boundaries of the left A-pillar of the driver's cab D a and the distance between the two boundaries of the right A-pillar of the driver's cab. D b The vehicle parameters for semi-trailer 3 include the longitudinal distance from the lead pin to the rear axle of semi-trailer 3. Driver's viewpoint parameters include: the distance from the driver's eye point to the right frame of the left side A. L lr Distance to the left edge of the right A-pillar L rlThe distance to the left side window 6 on the left side of the car L lol Distance to the right frame of the left-side window 6 L lor The distance to the left edge of the right-side window. L rol 5. Distance to the right side window and the right side frame L ror Distance to the left side of the A-pillar L ll Distance to the right side of the A-pillar L rr Ramp geometry parameters include ramp radius. and lane width W l The parameters for ramp guardrails include the distance between the inner guardrail of the curve and the inner lane edge. L nh The distance between the outer guardrail of the curve and the outer lane edge line L wh .
[0023] The parameters mentioned above can be referenced from SAE J941-2008 published by the Society of Automotive Engineers (SAE), using the 95th percentile eye ellipse as the calculation benchmark. This means that the parameter represents the statistical boundary of the eye point distribution for 95% of drivers in a specific seating position.
[0024] Optionally, constructing an articulated train model that considers the blind spots of a single semi-trailer tractor includes: Based on the driver's viewpoint parameters, the following are obtained: the forward semi-blind zone 8 is determined by the boundaries of the left and right A-pillars 7; the left semi-blind zone 10 is determined by the boundary of the left window 6; the right semi-blind zone 9 is determined by the boundary of the right window 5; and the A-pillar complete blind zone is determined by the boundaries of the left and right A-pillars 7. Each blind spot is treated as a virtual extension of the vehicle body and superimposed onto the physical outline of the vehicle body. The generalized geometric boundary of the articulated train, including the blind spots, is reconstructed to obtain the geometric model of the articulated train.
[0025] refer to Figure 2 Specifically, the design method for an articulated train model considering the blind spots of a single semi-trailer tractor is as follows: The first step is to calculate the semi-blind spot 8 in the driver's cab of the semi-trailer tractor, caused by the obstruction of the front vehicle structure (i.e., the structure below the front side window 4), based on the driver's viewpoint parameters. MQ f : , , , in: The angle between the lines of sight defined by the boundary rays of the left and right A-pillars 7 is expressed in rad. This represents the transition process from the left boundary to the right boundary, with a value range of [0,1]. This represents the maximum radial boundary of the semi-blind zone 8 in front of the field of vision, in meters. The results were obtained by having multiple drivers operate a semi-trailer truck with three tractors and measuring the blind spots on the actual vehicle. For r f From 0 The points are selected between [0, 1], and the values range from [0, 1]. The polar angle of any point within the blind spot of the foreground, in rad; The radial distance from any point to the eye point is expressed in meters (m). To fit a formula using data from measurements of blind spots taken by multiple drivers operating a three-tractor semi-trailer truck on actual vehicles, By making the parameters Taking values continuously within the interval from 0 to 1 ensures that the function The ability to linearly traverse all points within the target interval ensures that the calculation results are no longer isolated discrete points, but rather form a geometrically continuous boundary line. Forward semi-blind zone 8 MQ f The blind spot is a sector-shaped area. First, the included angle and radius are calculated, then the area swept by the radius is used to quantify the blind spot. The above formula is designed based on vehicle geometry and geometric optics principles. It considers the geometric relationship between the driver's eye point, the vehicle body structure, and the interaction between the driver's line of sight and the boundary rays of the left and right A-pillars 7. By calculating the viewing angle and distance from the driver's eye point to the boundaries of the left and right A-pillars 7, the range of the semi-blind spot 8 in the forward field of vision is obtained.
[0026] The second step is to calculate the left-side semi-blind spot (10) formed by the driver's left-side view in the cab of the semi-trailer tractor due to obstruction by the left-side door (i.e., the left-side window 6 is obstructed by the lower side door) based on the driver's viewpoint parameters. MQ l : , , in: The angle of view is defined by the left and right boundary rays of the left side window 6, in rad. s This represents the transition process from the left edge of the left window 6 to the right edge of the window, with a value range of [0,1]. Used to select points between 0 and 1.8. 1.8 is the data result obtained by having multiple drivers drive the semi-trailer 3 tractor through the actual vehicle to measure the blind spot. The blind spot of the driver in the left window 6 is approximately a fan shape with a radius of 1.8m, and the value range is [0,1]. The polar angle of any point within the blind spot of the foreground, in rad; Radial distance from any point to the eyepoint, in meters (m). Left visual field semi-blindness zone: 10. MQ l The formula design is based on vehicle geometry and geometric optics principles. It considers the geometric relationship between the driver's eye point and the vehicle body structure, as well as the interaction between the driver's line of sight and the left and right boundary rays of the left window 6. By calculating the viewing angle and distance from the driver's eye point to the left and right edges of the left window 6, the range of the left semi-blind spot 10 is obtained.
[0027] The third step is to calculate the right-side semi-blind spot 9 formed by the driver's right-side view being obstructed by the right-side door (i.e., the right-side window 5 is blocked by the lower side door) in the cab of the semi-trailer tractor, based on the driver's viewpoint parameters. MQ r : , , in: The angle of view is defined by the left and right boundary rays of the right-side window 5, in rad. s This represents the transition process from the left edge of the right-side window 5 to the right edge of the right-side window 5, with a value range of [0,1]. Used to select points between 0 and 2.5. 2.5 is the result of measuring the blind spot by having multiple drivers drive the semi-trailer 3 to the actual vehicle. The blind spot of the driver in the left window 6 is approximately a fan-shaped area with a radius of 2.5m, and the value range is [0,1]. The polar angle of any point within the blind spot of the foreground, in rad; The radial distance from any point to the eye point is expressed in meters (m).
[0028] The fourth step is to calculate the blind spot area (11) formed by the left and right A-pillars in the driver's cab of the semi-trailer tractor, due to the obstruction of the left and right A-pillars, based on the driver's viewpoint parameters. MQ a , MQ b : , , , , in: The angle of view is defined by the left and right boundary rays of the left / right A-pillars, in rad. s This represents the transition process from the left boundary to the right boundary of the left / right A-pillar, with a value range of [0,1]. Used in 0 and The points are selected between [0, 1); The polar angle of any point within the blind spot, in rad; The radial distance from any point to the eyepoint, in meters. The area of the complete blind spot within the visual field of the A-pillars on both sides. MQ a , MQ b The formula design is based on vehicle geometry and geometric optics principles. It considers the geometric relationship between the driver's eye point and the vehicle body structure, as well as the interaction between the driver's line of sight and the left / right boundary rays of the A-pillar. By calculating the viewing angle and distance from the driver's eye point to the left / right boundary of the A-pillar, the range of the left-side semi-blind zone 10 is obtained.
[0029] Fifth step: Based on the semi-blind spot range of the driver's forward visibility of the semi-trailer tractor (8 meters). MQ f Left-side visual field semi-blind zone within 10 range MQ l Right-side blind spot (range 9) MQ r 11 blind spots on both sides of the A-pillars MQ a , MQ b And the vehicle parameters of the semi-trailer tractor 1, including the blind spots (the range of the forward semi-blind spot 8). MQ f Left-side visual field semi-blind zone within 10 range MQ l Right-side blind spot (range 9) MQ r 11 blind spots on both sides of the A-pillars MQ a , MQ b The blind spot is considered as a virtual extension of the vehicle body. By superimposing the geometric boundary of the blind spot onto the physical outline of the vehicle body, the generalized geometric boundary of the articulated train, which includes the blind spot, is reconstructed, and the geometric model of the articulated train is obtained.
[0030] like Figure 3 As shown, the model for the motion trajectory of an articulated train considering the maximum cross-track difference of 13 includes: Based on the vehicle parameters of the semi-trailer tractor 1 and the geometric design parameters of the ramp, the radius of the trajectory 18 of the left front wheel of the semi-trailer tractor 1 when it travels along the edge of the outer lane line is obtained. Using the radius of the left front wheel track as the guiding reference, and based on the vehicle parameters and kinematic geometry of the semi-trailer 3, the radius of the right rear wheel motion trajectory 16 of the semi-trailer 3 is obtained. Based on the wheel track radius of the left front wheel and the wheel track radius of the right rear wheel, the articulation angle between the semi-trailer tractor 1 and the semi-trailer 3 and the maximum cross wheel track difference 13 are determined, thus obtaining the articulated train motion trajectory model.
[0031] Specifically, the design method for the motion trajectory of an articulated train considering a maximum cross-track difference of 13 is as follows: The first step involves the solid edge line of the lane, which presents the most challenging turning condition, preventing further outward extension. When the left front wheel of the semi-trailer tractor 1 travels along the edge of the outer lane line, the radius of its trajectory 18 can be calculated as follows: it equals the design radius of the ramp plus the width of the driving lane 14, plus the distance between the inner guardrail of the curve and the inner edge line of the lane. Based on the vehicle parameters of the semi-trailer tractor 1 and the ramp geometry, the radius of the left front wheel's track is calculated under the most unfavorable condition of traveling along the edge of the outer lane line. :
[0032] , in: For the left front wheel of the tractor, in parameters The radius of the wheel track at the corresponding position, in meters. Let be any point on the ramp while driving.
[0033] The second step, based on the vehicle parameters of the semi-trailer 3 and the geometric parameters of the ramp, and using the left front wheel track radius determined in the first step... Using the articulation angle generated by the articulation structure 2 between the semi-trailer tractor 1 and the semi-trailer 3 and the vehicle kinematic geometry, the radius of the right rear wheel track of the semi-trailer 3 is calculated. : , , in, The articulation angle between the tractor and the semi-trailer is expressed in rad. It describes the steering relationship between the front and rear of the vehicle (e.g., the angular relationship between the tractor and the semi-trailer), which is simplified using the Pythagorean theorem. It is the radius of the rear wheel track, which is obtained by simplifying calculations using the Pythagorean theorem and similar triangles. The quantitative formula is mainly for the convenience of determining whether the vehicle will collide with the guardrail later.
[0034] The radius of the wheel track of the left front wheel of the semi-trailer tractor 1 and the radius of the right rear wheel track of the semi-trailer 3 This is a crucial component of the entire articulated train trajectory model. Specifically, the left front wheel and right front wheel of semi-trailer tractor 1 are parallel and separated by a fixed distance between them. Therefore, the trajectory 12 of the right front wheel of tractor 1 is the trajectory 18 of the left front wheel of tractor 1 minus the distance between the vehicle bodies. Similarly, the wheel tracks of the right rear wheel and the left rear wheel of semi-trailer 3 are also parallel, and their relative distance is determined by the vehicle body geometry. Thus, the trajectories of the left front wheel of semi-trailer tractor 1 and the right rear wheel of semi-trailer 3 effectively reflect the entire travel path of the articulated train. Using these two wheel track radii, the angular changes, travel paths, and interactions between the tractor and semi-trailer 3 can be further calculated, providing the necessary mathematical model for accurately describing and optimizing the trajectory of the articulated train.
[0035] Optionally, determining the nonlinear widening value of the outer side of the ramp curve under the influence of blind spots includes: Obtain the maximum boundary distance of each blind spot; Select the corresponding maximum blind spot boundary distance based on the turning direction; Determine whether the outer guardrail of the curve is within the boundary of the maximum blind spot. If it is within the blind spot, the single-point widening value is obtained by combining the difference between the maximum blind spot boundary distance and the distance from the guardrail to the lane edge line with the safety factor.
[0036] Specifically, the nonlinear widening design method for the outer side of a ramp curve, considering blind spots, is as follows: The first step is to determine the semi-blind spot range (8 meters) in front of the driver of the semi-trailer tractor. MQ f Left-side visual field semi-blind zone within 10 range MQ l Right-side blind spot (range 9) MQ r And the blind spot of the A-pillars on both sides within 11 range. MQ a , MQ b Calculate the boundary distance of the driver's blind spot: , , , , , in, The maximum boundary distance of the semi-blind zone 8 in frontal vision; The maximum boundary distance of the left semi-blind zone within a 10-degree radius; This represents the maximum boundary distance of the right-side blind spot (9). The maximum boundary distance of the blind spot formed by the left A-pillar This represents the maximum boundary distance of the blind spot obstructed by the right-side A-pillar. The above formula determines the maximum boundary by taking the maximum value from the previous blind spot calculation formula.
[0037] The second step is to determine the boundary distance of the driver's blind spot, specifically the boundary distance of the driver's maximum blind spot when turning. It depends on the specific situation. When turning left, the blind spot is in front, while the guardrail is on the right; therefore, the maximum value of the right-side blind spot needs to be determined. When turning right, the blind spot remains the same, but the guardrail appears on the left; therefore, the maximum value of the left-side blind spot needs to be determined. Thus, the boundary distance of the maximum blind spot when the driver is turning is calculated. :
[0038] When turning left; When turning right; The third step is to determine whether the guardrail is inside the driver's blind spot based on the boundary of the blind spot: The guardrail is in a blind spot; The guardrail is outside the blind spot; Step 4: When the guardrail ramp is within the blind spot, calculate the widening value at point 15 on the outer side of the ramp: When turning left; When turning right; in, This is a safety factor for the widening value at a single point (15) on the outer guardrail of the ramp. This safety factor is primarily used during the engineering design process to round the widening value, ensuring the safety and practicality of the design. Its value should be adjusted according to actual conditions to ensure that various traffic environments and vehicle characteristics are fully considered. The widening value at a single point (15) on the outer guardrail of the ramp is equal to the distance of the vehicle's maximum blind spot minus the distance from the guardrail to the lane edge line, multiplied by a safety factor.
[0039] Optionally, determining the nonlinear widening value of the inner side of the ramp curve under the influence of trajectory difference includes: Obtain the trajectory difference between the radius of the left front wheel track of semi-trailer tractor 1 and the radius of the right rear wheel track of semi-trailer 3; Determine whether the guardrail on the inside of the curve will conflict with the movement trajectory of the semi-trailer 3; If a conflict occurs, the single-point widening value is obtained based on the trajectory difference, lane width, and distance from the guardrail to the inner lane edge, combined with the safety factor.
[0040] Specifically, the design method for the nonlinear widening design model of the inner side of the ramp curve, considering a maximum cross-track difference of 13, is as follows: The first step is to determine the radius of the wheel track of the left front wheel of the semi-trailer tractor 1. and the radius of the right rear wheel track of the semi-trailer 3 Calculate the trajectory difference : , The second step involves determining whether the guardrail will conflict with the movement trajectory of the semi-trailer 3, based on the ramp's geometric parameters, the guardrail design parameters, and the difference between the left front wheel radius of semi-trailer tractor 1 and the right rear wheel trajectory of semi-trailer 3. The determination formula is as follows: The guardrail will not interfere with the movement trajectory of the semi-trailer. The guardrail will conflict with the movement trajectory of the semi-trailer. The third step is to calculate the widening value at point 19 on the inner side of the guardrail when the guardrail ramp is inside the blind spot. : , in, This is a safety factor for the widening value at point 19 of the inner guardrail of the ramp. The safety factor is mainly used during the engineering design process to appropriately round the widening value at point 19 of the inner guardrail, ensuring that the design meets both safety requirements and practicality. Its value should be adjusted according to the actual situation of the specific project to ensure that various traffic environments and vehicle characteristics are fully considered. The widening value at point 19 of the inner guardrail of the ramp... Equal to the radius of the left front wheel track of the semi-trailer tractor. Radius of the right rear wheel track of the semi-trailer 3 The difference, minus the lane width W l In addition, add the distance from the inner guardrail of the curve to the edge of the inner lane. L nh The final result is multiplied by a safety factor. This ensures that the guardrail will not collide with the semi-trailer 3. This safety factor is primarily used to appropriately round the widening value during the engineering design process, thereby ensuring that the design possesses both sufficient safety and practicality.
[0041] Optionally, the safety factor is a value adjusted according to the actual engineering situation, used to round or enlarge the widening value to ensure the safety and practicality of the design.
[0042] The second embodiment of the present invention provides a ramp nonlinear widening design system, comprising: The parameter acquisition module is used to collect vehicle parameters of semi-trailer tractor 1, semi-trailer 3, driver's viewpoint parameters, ramp geometric parameters, and ramp guardrail design parameters. The blind spot modeling module is used to construct an articulated train model that takes into account the blind spots of the semi-trailer tractor 1, based on the vehicle parameters of the semi-trailer tractor 1 and the driver's viewpoint parameters. The motion trajectory modeling module is used to construct a motion trajectory model of the articulated train that takes into account the maximum cross wheel track difference of 13, based on the vehicle parameters of semi-trailer tractor 1, semi-trailer 3, and ramp geometric design parameters. The outer widening calculation module is used to determine the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot, based on the articulated train model that takes into account the blind spot of one semi-trailer tractor. The inner widening calculation module is used to determine the nonlinear widening value of the inner side of the ramp curve under the influence of the trajectory difference, based on the articulated train motion trajectory model that considers the maximum cross wheel track difference of 13.
[0043] Optionally, the blind spot modeling module is used for: Obtain the geometric range of the forward semi-blind zone 8, the left semi-blind zone 10, the right semi-blind zone 9, and the A-pillar complete blind zone; Each blind spot is superimposed onto the vehicle body outline to generate a generalized geometric boundary model of the articulated train.
[0044] Optionally, the motion trajectory modeling module is used for: Obtain the radius of the wheel track of the left front wheel of the semi-trailer tractor 1 under the most unfavorable working conditions; Calculate the wheel track radius and articulation angle of the right rear wheel of the semi-trailer 3 based on vehicle kinematics. The maximum difference in the cross track distance is 13 based on the radius of the left front wheel and the right rear wheel tracks.
[0045] Example 1: The specific method for nonlinear widening of ramps provided in this embodiment of the invention is as follows: (A) Collect basic data, including vehicle parameters of semi-trailer tractor 1, vehicle parameters of semi-trailer 3, driver's viewpoint parameters, ramp geometric design parameters, and ramp guardrail design parameters.
[0046] In this step, the parameters for one semi-trailer tractor include the wheelbase of the semi-trailer tractor. One semi-trailer tractor unit with front axle track width Distance from the rear axle of the semi-trailer tractor to the center of the lead pin The distance between the left and right A-pillars of the driver's cab D f The distance of 6 widths from the left-side window of the driver's cab D l The distance of 5 widths from the right-side window of the driver's cab D r The distance between the two boundaries of the left A-pillar of the driver's cab D a The distance between the two boundaries of the right A-pillar of the driver's cab D b The vehicle parameters for semi-trailer 3 include the longitudinal distance from the lead pin to the rear axle of semi-trailer 3. This can be measured on a real vehicle or obtained from the car company; driver's viewpoint parameters include the distance from the driver's eye point to the right frame of the left side A. L lr The distance from the driver's eye level to the left edge of the right A-pillar L rl The distance from the driver's eye point to the left edge of the left-side window. L lol The distance from the driver's eye point to the right frame of the left-side window. L lor The distance from the driver's eye point to the left edge of the right-side window. L rol The distance from the driver's eye point to the right side window's right frame. L ror The distance from the driver's eye level to the left edge of the left A-pillar L ll Distance from the driver's eye point to the right side of the A frame L rr It can be obtained through actual vehicle measurements while the driver is inside the cab; ramp geometry parameters include ramp radius. and lane width W l The parameters for ramp guardrails include the distance between the inner guardrail of the curve and the inner lane edge. L nh The distance between the outer guardrail of the curve and the outer lane edge line L wh This information can be obtained through on-site traffic surveys.
[0047] (B) Based on the parameters of one semi-trailer tractor and the driver's viewpoint parameters collected in step (A), the design method for the articulated train model considering the blind spots of one semi-trailer tractor is as follows: (B1) Forward semi-blind spot 8 MQ fThis is the area obstructed by the front structure of the vehicle while the driver is inside the cab of a semi-trailer tractor, and its extent is: , , , in: The angle between the lines of sight defined by the boundary rays of the left and right A-pillars 7 is expressed in rad. This represents the transition process from the left boundary to the right boundary, with a value range of [0,1]. The maximum radial boundary of the semi-blind zone in frontal vision (8 meters); For 0 and The points are selected between [0, 1], and the values range from [0, 1]. The polar angle of any point within the blind spot of the foreground, in rad; The radial distance from any point within the sector to the eye point is expressed in meters (m).
[0048] In this embodiment, by obtaining viewpoint parameter data from actual vehicle measurements of the driver inside the driver's cab beforehand, the included angle of view determined by the boundary rays of the left and right A-pillars 7 is calculated. It is 1.857 rad, based on the forward field of view and the semi-blind zone of 8. MQ f The calculation formula shows that the semi-blind spot in front of the eyes is 8. MQ f The area is an arc-shaped region with the driver's eye point as the shooting point, with a radius that gradually changes from 1.8m to 2.5m, and is located in front of the cab of a semi-trailer tractor.
[0049] (B2) Left visual field semi-blind spot 10 MQ l This area is formed by the driver being inside the cab of a semi-trailer truck due to obstruction from the left-side door, and its extent is: , , in: The angle of view is defined by the left and right boundary rays of the left side window 6, in rad. s This represents the transition process from the left edge of the left window 6 to the right edge of the window, with a value range of [0,1]. Used to select points between 0 and 1.8, with a value range of [0,1]. The polar angle of any point within the blind spot of the foreground, in rad; The radial distance from any point within the sector to the eye point is expressed in meters (m).
[0050] In this embodiment, the angle of view determined by the left and right boundary rays of the left side window 6 is calculated. It is 1.457 rad, based on the left-side semi-blind zone of 10. MQ l The formula for determining this is as follows: at this time, the left visual field semi-blind zone is 10. MQ l An arc-shaped area with the driver's eye point as the shooting point, with a radius of 1.8m, is closely attached to the left door of the cab of one semi-trailer tractor.
[0051] (B3) Right-sided visual field semi-blind spot 9 MQ r This area is formed by the driver being inside the cab of a semi-trailer truck due to obstruction from the right-side door, and its extent is: , , in: The angle of view is defined by the left and right boundary rays of the right-side window 5, in rad. s This represents the transition process from the left edge of the right-side window 5 to the right edge of the right-side window 5, with a value range of [0,1]. Used to select a point between 0 and 2.5, with a value range of [0,1]. The polar angle of any point within the blind spot of the foreground, in rad; The radial distance from any point within the sector to the eye point is expressed in meters (m).
[0052] In this embodiment, the angle of view determined by the left and right boundary rays of the right-side window 5 is calculated. It is 0.347 rad, based on the right-side semi-blind zone 9. MQ r The formula for determining this is as follows: At this point, the right-side semi-blind zone is 9. MQ r An arc-shaped area with a radius of 2.5m, centered on the driver's eye level, is positioned close to the right-side door of the cab of a semi-trailer tractor.
[0053] (B4) Blind spots in the field of vision of the A-pillars on both sides 11 MQ a , MQ b This is the area formed by the driver's position inside the cab of a semi-trailer truck due to the obstruction of the left and right A-pillars, and its range is as follows: , , , , in: The angle of view is defined by the left and right boundary rays of the left / right A-pillars, in rad. s This represents the transition process from the left boundary to the right boundary of the left / right A-pillar, with a value range of [0,1]. Used in 0 and The points are selected between [0, 1); The polar angle of any point within the blind spot, in rad; The radial distance from any point within the sector to the eye point is expressed in meters (m).
[0054] In this embodiment, the angle of view determined by the left and right boundary rays of the left / right A-pillars is calculated. These are 0.347 rad and 1.140 rad respectively, based on a left-side semi-blind zone of 10. MQ r The formula for determining this is such that the blind spot formed by column A is an infinite area.
[0055] (B5) The geometric model of the articulated train is based on the semi-blind spot 8 in front of the driver of the semi-trailer tractor, the semi-blind spot 10 on the left side, the blind spot 9 on the right side, the blind spot 11 on both sides of the A-pillar, and the vehicle parameters of the semi-trailer tractor. Each blind spot is regarded as a virtual extension structure of the vehicle body. By superimposing the geometric boundary of the blind spot onto the physical outline of the vehicle body, the generalized geometric boundary of the articulated train, which includes the blind spots, is reconstructed.
[0056] (C) Based on the parameters of the semi-trailer tractor 1, the semi-trailer 3, and the ramp geometry parameters collected in step (A), the articulated train motion trajectory model considering the maximum cross wheel track difference of 13 is calculated as follows: (C1) Radius of movement of the right front wheel of a semi-trailer tractor 1 This considers the radius of motion of the semi-trailer tractor 1 under the most unfavorable condition where its left front wheel travels along the edge of the outer lane line and does not intrude into the emergency stopping lane during a turn. The calculation formula is as follows: , in: For the left front wheel of the tractor, in parameters The radius of the wheel track at the corresponding position, in meters.
[0057] In this embodiment, a left turn is taken as an example, based on the travel radius of the right front wheel of the trailer tractor. The calculation formula is used to determine the radius of motion of the semi-trailer tractor when it makes a left turn. This requires considering the most unfavorable scenario where the right front wheel of the semi-trailer tractor 1 travels along the edge of the outer lane line without encroaching on the emergency stopping lane. It is 42.25m.
[0058] (C2) Radius of the left rear wheel of the semi-trailer Using the left front wheel track radius determined by C1 as the guiding reference, the right rear wheel track radius of the semi-trailer 3 is calculated using vehicle kinematic geometry. The calculation formula is as follows: , , in, The articulation angle between the tractor and the semi-trailer is expressed in rad.
[0059] In this embodiment, a left turn is taken as an example. Based on the movement radius of the right front wheel of the semi-trailer tractor 1 in (C1), the hinge angle between the tractor and the semi-trailer 3 is used. The calculation formula is used to determine the articulation angle between the tractor and the semi-trailer 3. The radius of the right rear wheel trajectory of semi-trailer 3 is −0.0945 rad. It is 38.68m.
[0060] (D) Based on the semi-blind spot 8 range in front of the driver of a semi-trailer tractor, the semi-blind spot 10 range on the left side, the semi-blind spot 9 range on the right side, and the total blind spot 11 range of the A-pillars on both sides calculated in step (B), a nonlinear widening design method for the outer side of the ramp curve considering the blind spots is proposed as follows: (D1) The boundary distance of the driver's blind spot is the distance between the outermost contour line of the blind spot coverage area and the vehicle body when each blind spot model reaches its maximum boundary range, calculated according to the corresponding formula: , , , , , in, The maximum boundary distance of the semi-blind zone 8 in frontal vision; The maximum boundary distance of the left semi-blind zone within a 10-degree radius; This represents the maximum boundary distance of the right-side semi-blind zone (9). This is the maximum boundary distance of the blind spot formed by the left A-pillar; This is the maximum boundary distance of the blind spot formed by the right-side A-pillar.
[0061] In this embodiment, a left turn is taken as an example. According to the corresponding calculation formula, the maximum boundary distance of the semi-blind spot 8 in the forward field of vision is... The maximum boundary distance of the left semi-blind zone is 2.5m. The maximum boundary distance of the right-side semi-blind zone (9 range) is 1.8m. The maximum boundary distance of the blind spot formed by the left A-pillar is 2.5m. The maximum boundary distance of the blind spot formed by the right-side A-pillar is ∞. It is ∞.
[0062] (D2) Boundary distance of the maximum blind spot The maximum boundary distance of the semi-blind spot in front of the driver when turning. Distance from the maximum boundary of the left semi-blind zone 10 Or the maximum boundary distance of the right-side semi-blind zone 9 range The maximum value in the formula represents the farthest limit of the blind spot relative to the outer contour of the vehicle body during turning. Its calculation formula is: When turning left; When turning right; In this embodiment, a left turn is taken as an example, based on the boundary distance of the maximum blind spot. The calculation formula is used to measure the boundary distance of the maximum blind spot. It is the maximum boundary distance of the semi-blind spot in the driver's forward field of vision. Distance from the maximum boundary of the right-side semi-blind zone 9 The maximum value in the range, the boundary distance of the maximum blind spot. It is 2.5m.
[0063] (D3) Based on the boundaries of the driver's blind spot in (D2) Determine if the guardrail is inside a blind spot: The guardrail is in a blind spot; The guardrail is outside the blind spot; In this embodiment, a left turn is taken as an example. The boundary distance of the maximum blind spot is calculated based on (D2). It is 2.5m, but in the field survey It is 2m. The guardrail is in a blind spot.
[0064] (D4) Widening value at point 15 on the outer side of the ramp guardrail: When the guardrail ramp is located within the blind spot, the widening value at point 15 on the outer side of the ramp guardrail is calculated using the following formula: When turning left; When turning right; in, The safety factor is the widening value at point 15 of the outer guardrail of the ramp.
[0065] In this embodiment, a left turn is used as an example, and the safety factor for widening the guardrail at point 15 on the outer side of the ramp is considered. A value of 1.5 is used to ensure a sufficient safety buffer distance between the guardrail and the blind spot boundary of the semi-trailer tractor 1, thereby maximizing the guardrail's position outside the driver's blind spot. This represents the widening value at a single point on the outer guardrail 15 of the ramp. It is 0.75m.
[0066] (E) Based on the motion radius of the right front wheel of the semi-trailer tractor 1 and the motion trajectory radius of the left rear wheel of the semi-trailer 3 in step (C), the following nonlinear widening design model for the inner side of the ramp curve, considering the maximum cross wheel track difference of 13, is proposed: (E1) Trajectory difference It is the difference between the wheel track radii of the left front wheel of semi-trailer tractor 1 and the two maximum intersecting wheel tracks of the right rear wheel of semi-trailer 3. The calculation formula is as follows: , In this embodiment, based on the (C1) right front wheel travel radius of the semi-trailer tractor 1 The radius of the left rear wheel's trajectory of the semi-trailer (C2) Calculate the trajectory difference It is 3.57m.
[0067] (E2) Based on the trajectory difference in (E1) To determine whether the guardrail will conflict with the movement trajectory of the semi-trailer, the formula is as follows: The guardrail will not interfere with the movement trajectory of the semi-trailer. The guardrail will conflict with the movement trajectory of the semi-trailer. In this embodiment, trajectory difference It is 3.57m, while in the field survey When it is 0.5m, The guardrail is in a blind spot.
[0068] The third step is to calculate the widening value at point 19 on the inner side of the guardrail when the guardrail ramp is inside the blind spot. : , in, The safety factor is the widening value at point 19 of the inner guardrail of the ramp.
[0069] In this embodiment, a left turn is used as an example, and the safety factor for widening the guardrail at point 15 on the outer side of the ramp is considered. Take 20 to ensure sufficient safety buffer space between the guardrail and the semi-trailer's trajectory, maximizing the lateral clearance. This is the widening value at a single point 15 on the outer guardrail of the ramp. It is 0.4m.
[0070] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A method for nonlinear widening design of ramps, characterized in that, Includes the following steps: Collect semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, driver's viewpoint parameters, ramp geometric parameters, and ramp guardrail design parameters; Based on the vehicle parameters of the semi-trailer tractor and the driver's viewpoint parameters, an articulated train model considering the blind spots of the semi-trailer tractor is constructed. Based on the semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, and ramp geometric design parameters, an articulated train motion trajectory model considering the maximum cross wheel track difference is constructed. Based on the articulated train model that takes into account the blind spot of the semi-trailer tractor, the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot is determined. Based on the articulated train motion trajectory model considering the maximum cross wheel track difference, the nonlinear widening value of the inner side of the ramp curve under the influence of the track difference is determined.
2. The nonlinear widening design method for ramps as described in claim 1, characterized in that: The parameters of the semi-trailer tractor include: wheelbase. Front axle track Distance from rear axle to the center of the lead pin The distance between the left and right A-pillars of the driver's cab D f The distance of the left-side window of the driver's cab D l The distance of the right-side window of the driver's cab D r The distance between the two boundaries of the left A-pillar of the driver's cab D a and the distance between the two boundaries of the right A-pillar of the driver's cab. D b ; The semi-trailer vehicle parameters include the longitudinal distance from the lead pin to the rear axle of the semi-trailer. ; The driver's viewpoint parameters include: the distance from the driver's eye point to the right frame of the left side A. L lr Distance to the left edge of the right A-pillar L rl Distance to the left edge of the left side window L lol Distance to the right frame of the left side window L lor Distance to the left edge of the right-side window L rol Distance to the right side frame of the right-side window L ror Distance to the left side of the A-pillar L ll Distance to the right side of the A-pillar L rr ; The ramp geometry parameters include the ramp radius. and lane width W l ; The parameters for the ramp guardrails include the distance between the inner guardrail of the curve and the inner lane edge line. L nh The distance between the outer guardrail of the curve and the outer lane edge line L wh .
3. The nonlinear widening design method for ramps as described in claim 1, characterized in that, The construction of the articulated train model that takes into account the blind spots of semi-trailer tractors includes: Based on the driver's viewpoint parameters, the following are obtained: the forward semi-blind zone determined by the left and right A-pillar boundaries, the left semi-blind zone determined by the left window boundary, the right semi-blind zone determined by the right window boundary, and the A-pillar complete blind zone determined by the left and right A-pillar boundaries. Each blind spot is considered as a virtual extension of the vehicle body and superimposed onto the physical outline of the vehicle body. The generalized geometric boundary of the articulated train, which includes blind spots, is reconstructed to obtain the geometric model of the articulated train.
4. The nonlinear widening design method for ramps as described in claim 1, characterized in that, The construction of the articulated train motion trajectory model considering the maximum cross-track difference includes: Based on the vehicle parameters of the semi-trailer tractor and the geometric design parameters of the ramp, the radius of the wheel track when the left front wheel of the semi-trailer tractor travels along the edge of the outer lane line is obtained. Using the left front wheel track radius as a guiding reference, the right rear wheel track radius of the semi-trailer is obtained based on the semi-trailer vehicle parameters and vehicle kinematic geometry. Based on the wheel track radius of the left front wheel and the wheel track radius of the right rear wheel, the articulation angle between the tractor and the semi-trailer and the maximum cross wheel track difference are determined, thereby obtaining the motion trajectory model of the articulated train.
5. The nonlinear widening design method for ramps as described in claim 1, characterized in that, The determination of the nonlinear widening value of the outer side of the ramp curve under the influence of blind spots includes: Obtain the maximum boundary distance of each blind spot; Select the corresponding maximum blind spot boundary distance based on the turning direction; Determine whether the guardrail on the outside of the curve is within the boundary of the maximum blind spot. If it is within the blind spot, the single-point widening value is obtained by combining the difference between the maximum blind spot boundary distance and the distance from the guardrail to the lane edge line with the safety factor.
6. The nonlinear widening design method for ramps as described in claim 1, characterized in that, The determination of the nonlinear widening value of the inner side of the ramp curve under the influence of trajectory difference includes: Obtain the trajectory difference between the radius of the left front wheel track of the semi-trailer tractor and the radius of the right rear wheel track of the semi-trailer; Determine whether the guardrail on the inside of the curve will conflict with the movement trajectory of the semi-trailer; If a conflict occurs, the single-point widening value is obtained based on the trajectory difference, lane width, and distance from the guardrail to the inner lane edge, combined with the safety factor.
7. A nonlinear widening design method for ramps as described in claim 5 or 6, characterized in that, The safety factor is a value adjusted according to the actual situation of the project. It is used to round or amplify the widening value to ensure the safety and practicality of the design.
8. A nonlinear widening design system for ramps, characterized in that, include: The parameter acquisition module is used to collect semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, driver's viewpoint parameters, ramp geometric parameters, and ramp guardrail design parameters. The blind spot modeling module is used to construct an articulated train model that takes into account the blind spot of the semi-trailer tractor based on the vehicle parameters of the semi-trailer tractor and the driver's viewpoint parameters. The motion trajectory modeling module is used to construct a motion trajectory model of the articulated train that considers the maximum cross wheel track difference based on the semi-trailer tractor vehicle parameters, semi-trailer vehicle parameters, and ramp geometric design parameters. The outer widening calculation module is used to determine the nonlinear widening value of the outer side of the ramp curve under the influence of the blind spot, based on the articulated train model that takes into account the blind spot of the semi-trailer tractor. The inner widening calculation module is used to determine the nonlinear widening value of the inner side of the ramp curve under the influence of the trajectory difference, based on the articulated train motion trajectory model that considers the maximum cross wheel track difference.
9. The ramp nonlinear widening design system as described in claim 8, characterized in that, The blind spot modeling module is used for: Obtain the geometric range of the semi-blind spots in the frontal field of view, the semi-blind spots in the left side of the field of view, the semi-blind spots in the right side of the field of view, and the complete blind spot in the A-pillar field of view; Each blind spot is superimposed onto the vehicle body outline to generate a generalized geometric boundary model of the articulated train.
10. The ramp nonlinear widening design system as described in claim 8, characterized in that, The motion trajectory modeling module is used for: Obtain the radius of the wheel track of the left front wheel of the semi-trailer tractor under the most unfavorable working conditions; Calculate the wheel track radius and articulation angle of the right rear wheel of the semi-trailer based on vehicle kinematics; The maximum difference in the cross track distance is obtained based on the radius of the left front wheel and the right rear wheel tracks.