A multi-objective collaborative optimization method for obstacle avoidance trajectory decision-making

Abstract

The present invention discloses a multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method, including an obstacle avoidance behavior classification method, an obstacle avoidance trajectory fitting method, and a multi-objective comprehensive evaluation method; the obstacle avoidance behavior classification method is used to subdivide the obstacle avoidance behavior into several categories of obstacle avoidance schemes according to a preset obstacle avoidance strategy; the obstacle avoidance trajectory fitting method is used to fit and generate obstacle avoidance behavior trajectory clusters under several categories of obstacle avoidance schemes; a multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on actual vehicle state information and safety threshold information, and the degree of proximity of each obstacle avoidance behavior trajectory to an ideal solution is calculated based on the multi-objective evaluation index, and the obstacle avoidance behavior trajectory with the highest proximity value is selected as the result of the multi-objective collaborative optimization obstacle avoidance behavior trajectory decision; the multi-objective comprehensive evaluation method includes a safety evaluation index, a comfort evaluation index, and an efficiency evaluation index; the decision is made to obtain the optimal obstacle avoidance behavior trajectory, thereby improving obstacle avoidance safety, comfort, and efficiency.

Description

Technical Field

[0001] The present invention relates to the field of vehicle obstacle avoidance decision-making, and in particular to the field of a multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method. Background Art

[0002] In today's production and life, assisted driving and autonomous driving have gradually become part of our lives; obstacle avoidance behavior decisions during driving are particularly important.

[0003] The goal of obstacle avoidance behavior planning is to fully utilize sensory information to timely select the optimal driving behavior, providing a reference for subsequent obstacle avoidance planning and control. Current obstacle avoidance behavior decision-making methods fall into two categories: rule-based and learning-based. Their outputs are primarily discrete driving action commands. While these methods reduce the complex obstacle avoidance planning problem to a specific obstacle avoidance behavior planning subproblem, providing a reference for obstacle avoidance actions, they do not effectively constrain the feasible solution space for subsequent planning and control optimization iterations. Furthermore, they lack continuous guidance during trajectory planning and control, failing to ensure consistency between actual obstacle avoidance behavior and behavioral decision-making results, nor effectively improve the real-time performance of obstacle avoidance trajectory planning and control.

[0004] Therefore, how to invent an obstacle avoidance behavior trajectory decision-making method that comprehensively considers obstacle avoidance strategies such as braking, steering, and speed steering, generates diversified obstacle avoidance behavior trajectories, and comprehensively evaluates candidate obstacle avoidance behavior trajectories based on obstacle avoidance safety, comfort, and efficiency, determines the obstacle avoidance behavior trajectory of multi-objective collaborative optimization, and provides effective guidance for obstacle avoidance planning and control has become a difficult problem that needs to be solved urgently in this field. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method to obtain the optimal obstacle avoidance behavior trajectory, provide effective guidance for obstacle avoidance control, and comprehensively improve obstacle avoidance safety, comfort and efficiency.

[0006] The present invention provides a multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method, including an obstacle avoidance behavior classification method, an obstacle avoidance trajectory fitting method, and a multi-objective comprehensive evaluation method;

[0007] The obstacle avoidance behavior classification method is used to subdivide the obstacle avoidance behavior into several types of obstacle avoidance schemes according to the preset obstacle avoidance strategy;

[0008] Generate obstacle avoidance behavior trajectory clusters by fitting under several types of obstacle avoidance schemes using the obstacle avoidance trajectory fitting method;

[0009] A multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on the actual vehicle status information and safety threshold information. Based on the multi-objective evaluation index, the degree of proximity of each obstacle avoidance trajectory to the ideal solution is calculated, and the obstacle avoidance trajectory with the highest proximity value is selected as the result of the multi-objective collaborative optimization obstacle avoidance trajectory decision.

[0010] The obstacle avoidance behavior classification method includes a preset obstacle avoidance strategy and an obstacle avoidance scheme classification method;

[0011] The preset obstacle avoidance strategies include braking obstacle avoidance strategy, steering obstacle avoidance strategy, and speed-changing steering obstacle avoidance strategy;

[0012] The braking obstacle avoidance strategy includes a smooth braking obstacle avoidance scheme, an emergency braking obstacle avoidance scheme, and a full braking obstacle avoidance scheme;

[0013] The steering obstacle avoidance strategy includes a smooth steering obstacle avoidance scheme and an emergency steering obstacle avoidance scheme;

[0014] The speed-changing steering obstacle avoidance strategy includes an obstacle avoidance scheme of accelerating first and then steering, and an obstacle avoidance scheme of decelerating first and then steering;

[0015] The multi-objective evaluation index includes a safety evaluation index, a comfort evaluation index and an efficiency evaluation index.

[0016] Compared with the existing technology, the present invention has the following beneficial effects: by including an obstacle avoidance behavior classification method, an obstacle avoidance trajectory fitting method, and a multi-objective comprehensive evaluation method, a preset obstacle avoidance strategy is refined into several types of schemes through the obstacle avoidance behavior classification method, and then the obstacle avoidance trajectory fitting method is used to fit and generate obstacle avoidance behavior trajectory clusters under several types of obstacle avoidance schemes, thereby obtaining several obstacle avoidance behavior trajectories with obstacle avoidance scheme category identifications;

[0017] A multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on the vehicle's actual state information and safety threshold information. Based on the multi-objective evaluation index, the proximity of each obstacle avoidance trajectory to the ideal solution is calculated. Using obstacle avoidance safety, comfort, and efficiency as evaluation dimensions, evaluation indicators are constructed for different categories of obstacle avoidance trajectories. The multi-objective evaluation value of each obstacle avoidance trajectory is calculated, and the degree of proximity to the ideal solution is calculated.

[0018] The optimal decision of obstacle avoidance trajectory is achieved by selecting the obstacle avoidance trajectory with the highest proximity value as the result of multi-objective collaborative optimization of obstacle avoidance trajectory decision;

[0019] The preset obstacle avoidance strategies include braking obstacle avoidance strategies, steering obstacle avoidance strategies, and speed-shifting steering obstacle avoidance strategies; the multi-objective evaluation indicators include safety evaluation indicators, comfort evaluation indicators, and efficiency evaluation indicators;

[0020] Based on the fitted obstacle avoidance behavior trajectory clusters, an evaluation index is constructed around the three dimensions of safety, comfort, and efficiency, combined with the actual vehicle status information and safety threshold information. The obstacle avoidance behavior trajectories are quantitatively evaluated, and the degree of proximity of each obstacle avoidance behavior trajectory to the ideal solution is calculated. Based on this, the obstacle avoidance behavior trajectory for multi-objective collaborative optimization is selected.

[0021] Furthermore, the obstacle avoidance schemes include smooth braking to avoid obstacles, emergency braking to avoid obstacles, full braking to avoid obstacles, smooth steering to avoid obstacles, emergency steering to avoid obstacles, accelerating first and then steering to avoid obstacles, and decelerating first and then steering to avoid obstacles;

[0022] The obstacle avoidance scheme classification method includes:

[0023] During obstacle avoidance, , ,and It is a smooth braking and obstacle avoidance solution;

[0024] when , ,and It is an emergency braking obstacle avoidance solution;

[0025] when , ,and It is a full braking obstacle avoidance solution;

[0026] when , For smooth steering and obstacle avoidance solutions;

[0027] when , To provide emergency steering and obstacle avoidance solutions;

[0028] when , It is an obstacle avoidance solution that slows down first and then turns;

[0029] when , It is an obstacle avoidance solution that accelerates first and then turns;

[0030] in is the longitudinal acceleration, is the lateral acceleration;

[0031] The obstacle avoidance trajectory fitting method is a piecewise third-order Hermite interpolation method, which fits several obstacle avoidance schemes to obtain an obstacle avoidance behavior trajectory cluster. The obstacle avoidance behavior cluster includes several obstacle avoidance behavior trajectories with obstacle avoidance scheme category identifiers.

[0032] The beneficial effects of the previous step are used to refine the preset obstacle avoidance strategy. On the one hand, diverse obstacle avoidance behavior trajectories are generated to enhance the completeness of the obstacle avoidance behavior. On the other hand, different obstacle avoidance behaviors have different calculation methods for corresponding evaluation indicators when conducting multi-objective comprehensive evaluation. By classifying obstacle avoidance behaviors, category identification can be formed, which facilitates the rapid determination of matching evaluation indicators.

[0033] Furthermore, the multi-objective comprehensive evaluation method includes:

[0034] Calculate the critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left front obstacle at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left rear obstacle at the initial moment of obstacle avoidance , the total time of the obstacle avoidance process ;

[0035] The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance Includes: Smooth braking to avoid obstacles. The critical safety distance in front is , Emergency braking obstacle avoidance critical safety distance in front , Full braking obstacle avoidance critical safety distance in front , Smooth steering to avoid obstacles and maintain the critical safety distance ahead , Emergency turn to avoid obstacles and critical safety distance in front , first accelerate and then turn to avoid the critical safety distance in front of the obstacle , first slow down and then turn to avoid the critical safety distance in front of the obstacle ;

[0036] The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance Includes: Smooth steering and obstacle avoidance, critical safety distance to the left front obstacle , Emergency steering to avoid the critical safety distance of the left front obstacle ; Accelerate first and then turn to avoid the critical safety distance of the obstacle in front of the left , first slow down and then turn to avoid the obstacle in front of the left critical safety distance ;

[0037] The critical safety distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance Includes: Smooth steering, obstacle avoidance, left rear obstacle, critical safety distance , Emergency steering to avoid obstacles at the critical safety distance behind the left rear obstacle , first accelerate and then turn to avoid the obstacle at the critical safety distance behind the left obstacle , first slow down and then turn to avoid the obstacle at the critical safety distance behind the left obstacle ;

[0038] The total time of the obstacle avoidance process Includes: Total time spent on smooth braking to avoid obstacles , the total time consumed by emergency braking to avoid obstacles , Total time consumed by full braking to avoid obstacles , the total time required for smooth steering and obstacle avoidance , the total time consumed in emergency steering to avoid obstacles , the total time taken to accelerate first and then turn to avoid obstacles , the total time taken to slow down first and then turn to avoid obstacles .

[0039] Furthermore, the critical safety distance in front of the brake to avoid obstacles It is calculated by formula 1, which is:

[0040] ;

[0041] Total time consumed by braking to avoid obstacles It is calculated by formula 2, which is:

[0042] ; , , ;

[0043] is the initial speed of the vehicle; is the speed of the obstacle ahead; is the longitudinal braking deceleration; is the braking system response time, ;

[0044] is the braking force growth time, ; The time it takes to brake continuously until the vehicle stops; The total time consumed in braking to avoid obstacles; Reserve a minimum safety distance between the vehicle and the obstacle ahead after the vehicle stops;

[0045] According to formula 1, Calculated; According to formula 2, Calculated;

[0046] According to formula 1, Calculated, According to formula 2, Calculated;

[0047] According to formula 1, Calculated, According to formula 2, Calculated.

[0048] The beneficial effect of the previous step is that the critical safety distance in front of the stable braking obstacle avoidance strategy is obtained through the above content. , emergency braking to avoid obstacles in front of the critical safety distance , full braking obstacle avoidance critical safety distance in front ; Total time spent on smooth braking to avoid obstacles , the total time consumed by emergency braking to avoid obstacles , Total time consumed by full braking to avoid obstacles Calculation method.

[0049] Furthermore, the critical safety distance in front of the steering obstacle avoidance It is calculated by formula 3, which is: ;

[0050] Critical collision moment and the total time consumed for steering and obstacle avoidance It is calculated by formula 4, which is:

[0051] ;

[0052] in, , , ,{t}_{sf}=\sqrt[{3}] {\frac {10\sqrt {3}×{Y}_{w}} {3×{a}_{ymax}}} , , ;

[0053] The position of the vehicle's center of mass at the critical collision moment; is the vehicle heading angle at the critical collision; Reserve a safe distance longitudinally for obstacle avoidance; is the distance between the center of mass of the vehicle and the front end of the vehicle; Reserve a safe distance laterally for obstacle avoidance; is the vehicle body width; The lateral boundary position of the obstacle directly ahead; is the maximum lateral acceleration; is the initial speed of the vehicle;

[0054] Steering obstacle avoidance left front obstacle critical safety distance It is calculated by formula 5, which is: ;

[0055] Steering obstacle avoidance left rear obstacle critical safety distance It is calculated by formula 6, which is: ;

[0056] is the full braking distance; is the initial speed of the vehicle; is the speed of the obstacle in front of the left; is the speed of the obstacle behind the left.

[0057] Further, According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when Calculated; According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when .

[0058] The beneficial effect of the previous step is that the critical safety distance in front of the smooth steering obstacle avoidance strategy can be obtained through the above content. , emergency turn to avoid obstacles at the critical safety distance ahead , smooth steering to avoid obstacles in front of the left critical safety distance , emergency turn to avoid the left front obstacle critical safety distance , smooth steering to avoid obstacles at the critical safety distance behind the left obstacle , emergency steering to avoid obstacles at the left rear, critical safety distance , the total time required for smooth steering and obstacle avoidance , the total time taken for emergency steering to avoid obstacles Calculation method.

[0059] Furthermore, the speed change turns to avoid the critical safety distance in front of the obstacle It is calculated by formula seven, which is:

[0060] ;

[0061] in, , ;

[0062] is the expected driving distance during the speed change phase; It is the critical safety distance in the turning phase; is the initial speed of the vehicle; is the target vehicle speed after the speed change; is the vehicle heading angle at the critical collision; is the distance between the center of mass of the vehicle and the front end of the vehicle; is the vehicle body width; is the width of the obstacle directly ahead; is the critical collision time of the steering process; To distribute the acceleration or braking response time of the vehicle, ;

[0063] Total time spent on speed change and obstacle avoidance It is calculated by formula 8, which is as follows:

[0064] ;

[0065] Speed ​​​​change and turn obstacle avoidance left front obstacle critical safety distance Calculated by formula nine, formula nine is:

[0066] ;

[0067] is the minimum braking distance; is the speed of the obstacle in front of the left;

[0068] Speed ​​Shift and Obstacle Avoidance Left Rear Obstacle Critical Safety Distance It is calculated by formula 10, which is:

[0069] ;

[0070] is the speed of the left rear obstacle.

[0071] Further, Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated;

[0072] Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated.

[0073] The beneficial effect of the previous step is that the critical safety distance in front of the obstacle avoidance strategy of accelerating first and then turning is obtained through the above content. , first slow down and then turn to avoid the obstacle directly in front of the critical safety distance , first accelerate and then turn to avoid the obstacle in front of the left critical safety distance , first slow down and then turn to the critical safety distance of the obstacle in front of the left , first accelerate and then turn to avoid the obstacle behind the left critical safety distance , first slow down and then turn to avoid the obstacle at the critical safety distance behind the left obstacle , the total time taken to accelerate first and then turn to avoid obstacles , first decelerate and then turn to avoid obstacles Calculation method.

[0074] Further, construct safety evaluation indicators , comfort evaluation index , efficiency evaluation indicators ;

[0075] Calculate the safety evaluation index value corresponding to each obstacle avoidance trajectory in the obstacle avoidance trajectory cluster based on multi-objective evaluation indicators , comfort evaluation index value and efficiency evaluation index values ;

[0076] Constructing an evaluation index matrix , , ;

[0077] is the number of obstacle avoidance behavior trajectories contained in the obstacle avoidance behavior trajectory cluster; Evaluation index dimensions, including safety evaluation index value, comfort evaluation index value, and efficiency evaluation index value, ;

[0078] Evaluation indicator matrix Perform normalization to obtain the normalized evaluation index matrix ;

[0079] ;

[0080] is any item in the evaluation index matrix; is the maximum evaluation value corresponding to the j-th evaluation index; is the minimum evaluation value corresponding to the j-th evaluation indicator;

[0081] Combined with the corresponding weights of safety evaluation index, comfort evaluation index and efficiency evaluation index Evaluation indicator matrix Perform weighted processing to obtain the weighted evaluation index matrix ;

[0082] ;

[0083] Determine the positive ideal value corresponding to each evaluation indicator and negative ideal values ;

[0084] , ;

[0085] Positive ideal value is the maximum value of the weighted evaluation value corresponding to the j-th evaluation index; negative ideal value is the minimum weighted evaluation value corresponding to the j-th evaluation index;

[0086] The relative distance between each obstacle avoidance trajectory and the positive ideal value and the negative ideal value is determined by the Euclidean distance, thereby calculating the degree of closeness of each obstacle avoidance trajectory to the ideal solution.

[0087] , , ;

[0088] in, For the The relative distance between each obstacle avoidance trajectory and the positive ideal value; For the The relative distance between the obstacle avoidance trajectory and the negative ideal value; For the The closeness between the obstacle avoidance trajectory and the ideal solution;

[0089] The obstacle avoidance trajectory with the largest proximity value is selected as the result of multi-objective collaborative optimization of obstacle avoidance trajectory decision.

[0090] The beneficial effect of adopting the previous step is to conduct a comprehensive quantitative evaluation of the obstacle avoidance behavior trajectory based on obstacle avoidance safety, comfort, and efficiency, determine the obstacle avoidance behavior trajectory of multi-objective collaborative optimization, and achieve the optimal decision of the obstacle avoidance behavior trajectory.

[0091] Furthermore, a safety evaluation index value is constructed based on the actual vehicle status information and safety threshold information , comfort evaluation index value , efficiency evaluation index value ;

[0092] ;

[0093] To avoid obstacles; Provides collision damage mitigation capabilities; Obstacle avoidance possibility; For speed change risk;

[0094] ;

[0095] The actual distance between the vehicle and the obstacle ahead; The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance;

[0096] when hour, , ;when hour, , ;

[0097] , ;

[0098] The degree of collision damage mitigation is determined by the severity of the potential collision at the end of obstacle avoidance. The severity of potential collision at the initial moment of obstacle avoidance The difference is determined; is the initial speed of the vehicle; The equivalent speed at the moment of collision, which is determined by the vehicle's speed and posture at the time of collision; is the potential collision object speed; is the vehicle quality; is the mass of potential collision object;

[0099] When the braking obstacle avoidance strategy is adopted, ;

[0100] When using the steering obstacle avoidance strategy or the speed-changing steering obstacle avoidance strategy, ;

[0101] The actual distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The actual distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance;

[0102] When adopting the braking obstacle avoidance strategy or the steering obstacle avoidance strategy, ;

[0103] When the acceleration steering obstacle avoidance strategy is adopted, , , , , ;

[0104] When the deceleration and steering obstacle avoidance strategy is adopted, , , , , ;

[0105] is the target vehicle speed after the speed change; The minimum speed limit for the road; The maximum speed limit for the road; is the actual deceleration or acceleration; and Implementing boundary values ​​for distributed drive vehicles , ;

[0106] ;

[0107] is the maximum longitudinal acceleration during the obstacle avoidance process, is the maximum lateral acceleration during obstacle avoidance;

[0108] is the longitudinal acceleration comfort threshold. , when using deceleration ; is the lateral acceleration comfort threshold, ;

[0109] , ;

[0110] is the road reference speed; is the average vehicle speed during the obstacle avoidance process; when the steering obstacle avoidance strategy is adopted, ;

[0111] When using the braking obstacle avoidance strategy or the speed change steering obstacle avoidance strategy, ; The actual longitudinal distance traveled during the obstacle avoidance process; The total time consumption for obstacle avoidance is: ;

[0112] When using the speed-changing steering obstacle avoidance strategy, .

[0113] The beneficial effect of adopting the previous step is that the safety evaluation index evaluates the collision risk based on the urgency of obstacle avoidance and the potential collision severity, and for the steering obstacle avoidance strategy and the speed change steering strategy, the possibility of lane change obstacle avoidance is evaluated based on the degree of interference from obstacles in adjacent lanes. At the same time, for the speed change steering obstacle avoidance strategy, the target vehicle speed after the speed change and the acceleration of the speed change process are constrained based on the requirements of traffic safety regulations and the actual implementation boundaries to construct a speed change risk index; the comfort evaluation index comprehensively considers the impact of the longitudinal and lateral speed change rates on driving comfort, and minimizes the sense of frustration during the obstacle avoidance process; the efficiency index requires the vehicle to complete the obstacle avoidance action as quickly as possible to minimize the obstruction to surrounding traffic; and finally determines the obstacle avoidance behavior trajectory of multi-objective collaborative optimization, providing effective guidance for subsequent obstacle avoidance control to comprehensively improve obstacle avoidance safety, comfort and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] Figure 1 The flowchart of the multi-objective collaborative optimization obstacle avoidance behavior trajectory decision method includes the multi-objective collaborative optimization obstacle avoidance behavior trajectory decision method of Example 1. DETAILED DESCRIPTION

[0115] In order to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and the accompanying drawings.

[0116] Example 1:

[0117] According to this embodiment, a multi-objective collaborative optimization obstacle avoidance behavior trajectory decision method is provided, including an obstacle avoidance behavior classification method, an obstacle avoidance trajectory fitting method, and a multi-objective comprehensive evaluation method;

[0118] The obstacle avoidance behavior classification method includes a preset obstacle avoidance strategy and an obstacle avoidance scheme classification method;

[0119] The preset obstacle avoidance strategies include braking obstacle avoidance strategy, steering obstacle avoidance strategy, and speed-changing steering obstacle avoidance strategy;

[0120] The braking obstacle avoidance strategy includes a smooth braking obstacle avoidance scheme, an emergency braking obstacle avoidance scheme, and a full braking obstacle avoidance scheme;

[0121] The steering obstacle avoidance strategy includes a smooth steering obstacle avoidance scheme and an emergency steering obstacle avoidance scheme;

[0122] The speed-changing steering obstacle avoidance strategy includes an obstacle avoidance scheme of accelerating first and then steering, and an obstacle avoidance scheme of decelerating first and then steering;

[0123] The obstacle avoidance scheme classification method includes:

[0124] During obstacle avoidance, , ,and It is a smooth braking and obstacle avoidance solution;

[0125] when , ,and It is an emergency braking obstacle avoidance solution;

[0126] when , ,and It is a full braking obstacle avoidance solution;

[0127] when , For smooth steering and obstacle avoidance solutions;

[0128] when , To provide emergency steering and obstacle avoidance solutions;

[0129] when , It is an obstacle avoidance solution that slows down first and then turns;

[0130] when , It is an obstacle avoidance solution that accelerates first and then turns;

[0131] in is the longitudinal acceleration, is the lateral acceleration.

[0132] The obstacle avoidance trajectory fitting method is used to fit and generate obstacle avoidance behavior trajectory clusters under several types of obstacle avoidance schemes; the obstacle avoidance trajectory fitting method adopts piecewise third-order Hermite interpolation to fit several obstacle avoidance behaviors to obtain obstacle avoidance behavior trajectory clusters, and the obstacle avoidance behavior trajectory clusters include several obstacle avoidance behavior trajectories with obstacle avoidance scheme category identifiers.

[0133] A multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on the actual vehicle status information and safety threshold information. Based on the multi-objective evaluation index, the degree of proximity of each obstacle avoidance trajectory to the ideal solution is calculated, and the obstacle avoidance trajectory with the highest proximity value is selected as the result of the multi-objective collaborative optimization obstacle avoidance trajectory decision.

[0134] A multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on the actual vehicle status information and safety threshold information. Based on the multi-objective evaluation index, the degree of proximity of each obstacle avoidance trajectory to the ideal solution is calculated, and the obstacle avoidance trajectory with the highest proximity value is selected as the result of the multi-objective collaborative optimization obstacle avoidance trajectory decision.

[0135] The multi-objective evaluation index includes a safety evaluation index, a comfort evaluation index and an efficiency evaluation index.

[0136] Multi-objective comprehensive evaluation methods include:

[0137] Calculate the critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left front obstacle at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left rear obstacle at the initial moment of obstacle avoidance , the total time of the obstacle avoidance process ;

[0138] The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance Includes: Smooth braking to avoid obstacles. The critical safety distance in front is , Emergency braking obstacle avoidance critical safety distance in front , Full braking obstacle avoidance critical safety distance in front , Smooth steering to avoid obstacles and maintain the critical safety distance ahead , Emergency turn to avoid obstacles and critical safety distance in front , first accelerate and then turn to avoid the critical safety distance in front of the obstacle , first slow down and then turn to avoid the critical safety distance in front of the obstacle ;

[0139] The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance Includes: Smooth steering and obstacle avoidance, critical safety distance to the left front obstacle , Emergency steering to avoid the critical safety distance of the left front obstacle ; Accelerate first and then turn to avoid the critical safety distance of the obstacle in front of the left , first slow down and then turn to avoid the obstacle in front of the left critical safety distance ;

[0140] The critical safety distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance Includes: Smooth steering, obstacle avoidance, left rear obstacle, critical safety distance , Emergency steering to avoid obstacles at the critical safety distance behind the left rear obstacle , first accelerate and then turn to avoid the obstacle at the critical safety distance behind the left obstacle , first slow down and then turn to avoid the obstacle at the critical safety distance behind the left obstacle ;

[0141] The total time of the obstacle avoidance process Includes: Total time spent on smooth braking to avoid obstacles , the total time consumed by emergency braking to avoid obstacles , Total time consumed by full braking to avoid obstacles , the total time required for smooth steering and obstacle avoidance , the total time consumed in emergency steering to avoid obstacles , the total time taken to accelerate first and then turn to avoid obstacles , the total time taken to slow down first and then turn to avoid obstacles .

[0142] Critical safety distance in front of the brake to avoid obstacles It is calculated by formula 1, which is:

[0143] ;

[0144] Total time consumed by braking to avoid obstacles It is calculated by formula 2, which is:

[0145] ; , , ;

[0146] is the initial speed of the vehicle; is the speed of the obstacle ahead; is the longitudinal braking deceleration; is the braking system response time, ;

[0147] is the braking force growth time, ; The time it takes to brake continuously until the vehicle stops; The total time consumed in braking to avoid obstacles; Reserve a minimum safety distance between the vehicle and the obstacle ahead after the vehicle stops;

[0148] According to formula 1, Calculated; According to formula 2, Calculated;

[0149] According to formula 1, Calculated, According to formula 2, Calculated;

[0150] According to formula 1, Calculated, According to formula 2, Calculated.

[0151] Critical safety distance in front of steering obstacle avoidance It is calculated by formula 3, which is: ;

[0152] Critical collision moment and the total time consumed for steering and obstacle avoidance It is calculated by formula 4, which is:

[0153] ;

[0154] in, , , ,{t}_{sf}=\sqrt[{3}] {\frac {10\sqrt {3}×{Y}_{w}} {3×{a}_{ymax}}} , , ;

[0155] The position of the vehicle's center of mass at the critical collision moment; is the vehicle heading angle at the critical collision; Reserve a safe distance longitudinally for obstacle avoidance; is the distance between the center of mass of the vehicle and the front end of the vehicle; Reserve a safe distance laterally for obstacle avoidance; is the vehicle body width; The lateral boundary position of the obstacle directly ahead; is the maximum lateral acceleration; is the initial speed of the vehicle;

[0156] Steering obstacle avoidance left front obstacle critical safety distance It is calculated by formula 5, which is: ;

[0157] Steering obstacle avoidance left rear obstacle critical safety distance It is calculated by formula 6, which is: ;

[0158] is the full braking distance; is the initial speed of the vehicle; is the speed of the obstacle in front of the left; is the speed of the obstacle behind the left.

[0159] According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when Calculated; According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when .

[0160] Speed ​​change and steering to avoid obstacles in front of the critical safety distance It is calculated by formula seven, which is:

[0161] ;

[0162] in, , ;

[0163] is the expected driving distance during the speed change phase; It is the critical safety distance in the turning phase; is the initial speed of the vehicle; is the target vehicle speed after the speed change; is the vehicle heading angle at the critical collision; is the distance between the center of mass of the vehicle and the front end of the vehicle; is the vehicle body width; is the width of the obstacle directly ahead; is the critical collision time of the steering process; To distribute the acceleration or braking response time of the vehicle, ;

[0164] Total time spent on speed change and obstacle avoidance It is calculated by formula 8, which is as follows:

[0165] ;

[0166] Speed ​​​​change and turn obstacle avoidance left front obstacle critical safety distance Calculated by formula nine, formula nine is:

[0167] ;

[0168] is the minimum braking distance; is the speed of the obstacle in front of the left;

[0169] Speed ​​Shift and Obstacle Avoidance Left Rear Obstacle Critical Safety Distance It is calculated by formula 10, which is:

[0170] ;

[0171] is the speed of the left rear obstacle.

[0172] Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated;

[0173] Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated.

[0174] Constructing safety evaluation indicators , comfort evaluation index , efficiency evaluation indicators ;

[0175] Calculate the safety evaluation index value corresponding to each obstacle avoidance trajectory in the obstacle avoidance trajectory cluster based on multi-objective evaluation indicators , comfort evaluation index value and efficiency evaluation index values ;

[0176] Construct safety evaluation index values ​​based on vehicle actual status information and safety threshold information , comfort evaluation index value , efficiency evaluation index value ;

[0177] ;

[0178] To avoid obstacles; Provides collision damage mitigation capabilities; Obstacle avoidance possibility; For speed change risk;

[0179] ;

[0180] The actual distance between the vehicle and the obstacle ahead; The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance;

[0181] when hour, , ;when hour, , ;

[0182] , ;

[0183] The degree of collision damage mitigation is determined by the severity of the potential collision at the end of obstacle avoidance. The severity of potential collision at the initial moment of obstacle avoidance The difference is determined; is the initial speed of the vehicle; The equivalent speed at the moment of collision, which is determined by the vehicle's speed and posture at the time of collision; is the potential collision object speed; is the vehicle quality; is the mass of potential collision object;

[0184] When the braking obstacle avoidance strategy is adopted, ;

[0185] When using the steering obstacle avoidance strategy or the speed-changing steering obstacle avoidance strategy, ;

[0186] The actual distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The actual distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance;

[0187] When adopting the braking obstacle avoidance strategy or the steering obstacle avoidance strategy, ;

[0188] When the acceleration steering obstacle avoidance strategy is adopted, , , , , ;

[0189] When the deceleration and steering obstacle avoidance strategy is adopted, , , , , ;

[0190] is the target vehicle speed after the speed change; The minimum speed limit for the road; The maximum speed limit for the road; is the actual deceleration or acceleration; and Implementing boundary values ​​for distributed drive vehicles , ;

[0191] ;

[0192] is the maximum longitudinal acceleration during the obstacle avoidance process, is the maximum lateral acceleration during obstacle avoidance;

[0193] is the longitudinal acceleration comfort threshold. , when using deceleration ; is the lateral acceleration comfort threshold, ;

[0194] , ;

[0195] is the road reference speed; is the average vehicle speed during the obstacle avoidance process; when the steering obstacle avoidance strategy is adopted, ;

[0196] When using the braking obstacle avoidance strategy or the speed change steering obstacle avoidance strategy, ; The actual longitudinal distance traveled during the obstacle avoidance process; The total time consumption for obstacle avoidance is: ;

[0197] When using the speed-changing steering obstacle avoidance strategy, .

[0198] Constructing an evaluation index matrix , , ;

[0199] is the number of obstacle avoidance behavior trajectories contained in the obstacle avoidance behavior trajectory cluster; Evaluation index dimensions, including safety evaluation index value, comfort evaluation index value, and efficiency evaluation index value, ;

[0200] Evaluation indicator matrix Perform normalization to obtain the normalized evaluation index matrix ;

[0201] ;

[0202] is any item in the evaluation index matrix; is the maximum evaluation value corresponding to the j-th evaluation index; is the minimum evaluation value corresponding to the j-th evaluation indicator;

[0203] Combined with the corresponding weights of safety evaluation index, comfort evaluation index and efficiency evaluation index Evaluation indicator matrix Perform weighted processing to obtain the weighted evaluation index matrix ;

[0204] ;

[0205] Determine the positive ideal value corresponding to each evaluation indicator and negative ideal values ;

[0206] , ;

[0207] Positive ideal value is the maximum value of the weighted evaluation value corresponding to the j-th evaluation index; negative ideal value is the minimum weighted evaluation value corresponding to the j-th evaluation index;

[0208] The relative distance between each obstacle avoidance trajectory and the positive ideal value and the negative ideal value is determined by the Euclidean distance, thereby calculating the degree of closeness of each obstacle avoidance trajectory to the ideal solution.

[0209] , , ;

[0210] in, For the The relative distance between each obstacle avoidance trajectory and the positive ideal value; For the The relative distance between the obstacle avoidance trajectory and the negative ideal value; For the The closeness between the obstacle avoidance trajectory and the ideal solution;

[0211] The obstacle avoidance trajectory with the largest proximity value is selected as the result of multi-objective collaborative optimization of obstacle avoidance trajectory decision.

[0212] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used; those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept; for example, the above-mentioned features have similar functions to those disclosed in this application (but not limited to).

Claims

1. A multi-objective collaborative optimization obstacle avoidance behavior trajectory decision method, characterized by: Including obstacle avoidance behavior classification method, obstacle avoidance trajectory fitting method, and multi-objective comprehensive evaluation method; The obstacle avoidance behavior classification method is used to subdivide the obstacle avoidance behavior into several types of obstacle avoidance schemes according to the preset obstacle avoidance strategy; Generate obstacle avoidance behavior trajectory clusters by fitting under several types of obstacle avoidance schemes using the obstacle avoidance trajectory fitting method; A multi-objective comprehensive evaluation method is used to construct a multi-objective evaluation index based on the actual vehicle status information and safety threshold information. Based on the multi-objective evaluation index, the degree of proximity of each obstacle avoidance trajectory to the ideal solution is calculated, and the obstacle avoidance trajectory with the highest proximity value is selected as the result of the multi-objective collaborative optimization obstacle avoidance trajectory decision. The obstacle avoidance behavior classification method includes a preset obstacle avoidance strategy and an obstacle avoidance scheme classification method; The preset obstacle avoidance strategies include braking obstacle avoidance strategy, steering obstacle avoidance strategy, and speed-changing steering obstacle avoidance strategy; The braking obstacle avoidance strategy includes a smooth braking obstacle avoidance scheme, an emergency braking obstacle avoidance scheme, and a full braking obstacle avoidance scheme; The steering obstacle avoidance strategy includes a smooth steering obstacle avoidance scheme and an emergency steering obstacle avoidance scheme; The speed-changing steering obstacle avoidance strategy includes an obstacle avoidance scheme of accelerating first and then steering, and an obstacle avoidance scheme of decelerating first and then steering; The multi-objective evaluation index includes a safety evaluation index, a comfort evaluation index and an efficiency evaluation index; Constructing safety evaluation indicators , comfort evaluation index , efficiency evaluation indicators ; Calculate the safety evaluation index value corresponding to each obstacle avoidance trajectory in the obstacle avoidance trajectory cluster based on multi-objective evaluation indicators , comfort evaluation index value and efficiency evaluation index values ; Constructing an evaluation index matrix , ; is the number of obstacle avoidance behavior trajectories contained in the obstacle avoidance behavior trajectory cluster; is the evaluation index dimension, including safety evaluation index value, comfort evaluation index value, and efficiency evaluation index value, that is, ; Evaluation indicator matrix Perform normalization to obtain the normalized evaluation index matrix ; ； is any item in the evaluation index matrix; The maximum value of the evaluation value corresponding to the j-th evaluation indicator; For the The minimum evaluation value corresponding to the evaluation indicator; Combined with the corresponding weights of safety evaluation index, comfort evaluation index and efficiency evaluation index Evaluation indicator matrix Perform weighted processing to obtain the weighted evaluation index matrix ; ; Determine the positive ideal value corresponding to each evaluation indicator and negative ideal values ; , ; Positive ideal value For the The maximum value of the weighted evaluation value corresponding to the evaluation index; negative ideal value For the The minimum weighted evaluation value corresponding to each evaluation indicator; The relative distance between each obstacle avoidance trajectory and the positive ideal value and the negative ideal value is determined by the Euclidean distance, thereby calculating the degree of closeness of each obstacle avoidance trajectory to the ideal solution. , , ; in, For the The relative distance between the obstacle avoidance trajectory and the positive ideal solution value; For the The relative distance between the obstacle avoidance trajectory and the negative ideal solution value; For the The closeness between the obstacle avoidance trajectory and the ideal solution; The obstacle avoidance trajectory with the largest proximity value is selected as the result of multi-objective collaborative optimization of obstacle avoidance trajectory decision.

2. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 1, characterized in that: The obstacle avoidance schemes include smooth braking, emergency braking, full braking, smooth steering, emergency steering, acceleration before steering, and deceleration before steering. The obstacle avoidance scheme classification method includes: During the obstacle avoidance process, when , ,and It is a smooth braking obstacle avoidance solution; , ,and It is an emergency braking obstacle avoidance solution; , ,and It is a full braking obstacle avoidance solution; when , For smooth steering and obstacle avoidance solutions; , For emergency steering obstacle avoidance plan; , It is an obstacle avoidance solution that decelerates first and then turns; when , It is an obstacle avoidance solution that accelerates first and then turns; is the longitudinal acceleration, is the lateral acceleration.

3. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 2, characterized in that: Multi-objective comprehensive evaluation methods include: Calculate the critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left front obstacle at the initial moment of obstacle avoidance , the critical safety distance between the main vehicle and the left rear obstacle at the initial moment of obstacle avoidance , the total time of the obstacle avoidance process ; The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance Includes: Smooth braking to avoid obstacles and a critical safety distance ahead , Emergency braking obstacle avoidance critical safety distance in front , Full braking obstacle avoidance critical safety distance in front , Smooth steering to avoid obstacles and maintain the critical safety distance ahead , Emergency turn to avoid obstacles and critical safety distance in front , first accelerate and then turn to avoid the critical safety distance in front of the obstacle , first slow down and then turn to avoid the critical safety distance in front of the obstacle ; The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance Includes: Smooth steering and obstacle avoidance, critical safety distance to the left front obstacle , Emergency steering to avoid the critical safety distance of the left front obstacle ; Accelerate first and then turn to avoid the critical safety distance of the obstacle in front of the left , first slow down and then turn to avoid the obstacle in front of the left critical safety distance ; The critical safety distance between the main vehicle and the left rear obstacle at the initial moment of obstacle avoidance Includes: Smooth steering, obstacle avoidance, left rear obstacle, critical safety distance , Emergency steering to avoid obstacles at the critical safety distance behind the left rear obstacle , first accelerate and then turn to avoid the obstacle at the critical safety distance behind the left obstacle , first slow down and then turn to avoid the obstacle at the critical safety distance behind the left obstacle ; The total time of the obstacle avoidance process Includes: Total time spent on smooth braking to avoid obstacles , the total time consumed by emergency braking to avoid obstacles , Total time consumed by full braking to avoid obstacles , the total time required for smooth steering and obstacle avoidance , the total time consumed in emergency steering to avoid obstacles , the total time taken to accelerate first and then turn to avoid obstacles , the total time taken to slow down first and then turn to avoid obstacles .

4. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 3, characterized in that: Critical safety distance in front of the brake to avoid obstacles It is calculated by formula 1, which is: ; Total time consumed by braking to avoid obstacles It is calculated by formula 2, which is: ; , , ; is the initial speed of the vehicle; is the speed of the obstacle ahead; is the longitudinal braking deceleration; is the braking system response time, ; is the braking force growth time, ; The time it takes to brake continuously until the vehicle stops; The total time consumed in braking to avoid obstacles; Reserve a minimum safety distance between the vehicle and the obstacle ahead after the vehicle stops; According to formula 1, Calculated; According to formula 2, Calculated; According to formula 1, Calculated, According to formula 2, Calculated; According to formula 1, Calculated, According to formula 2, Calculated.

5. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 3, characterized in that: Critical safety distance in front of steering obstacle avoidance It is calculated by formula 3, which is: ; Critical collision moment and the total time consumed for steering and obstacle avoidance It is calculated by formula 4, which is: ; in, , , , , , ; The position of the vehicle's center of mass at the critical collision moment; is the vehicle heading angle at the critical collision; Reserve a safe distance longitudinally for obstacle avoidance; is the distance between the center of mass of the vehicle and the front end of the vehicle; Reserve a safe distance laterally for obstacle avoidance; is the vehicle body width; The lateral boundary position of the obstacle directly ahead; is the maximum lateral acceleration; is the initial speed of the vehicle; Steering obstacle avoidance left front obstacle critical safety distance It is calculated by formula 5, which is: ; Steering obstacle avoidance left rear obstacle critical safety distance It is calculated by formula 6, which is: ; is the full braking distance; is the initial speed of the vehicle; is the speed of the obstacle in front of the left; is the speed of the obstacle behind the left.

6. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 5, characterized in that: According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when Calculated; According to formula 3, 、 According to formula 4, According to formula 5, According to formula 6, when Calculated.

7. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 3, characterized in that: Speed ​​change and steering to avoid obstacles in front of the critical safety distance It is calculated by formula seven, which is: ; in , ; is the expected driving distance during the speed change phase; It is the critical safety distance in the turning phase; is the initial speed of the vehicle; is the target vehicle speed after the speed change; is the vehicle heading angle at the critical collision; is the distance between the center of mass of the vehicle and the front end of the vehicle; is the vehicle body width; is the width of the obstacle directly ahead; is the critical collision time of the steering process; To distribute the acceleration or braking response time of the vehicle, ; Total time spent on speed change and obstacle avoidance It is calculated by formula 8, which is as follows: ; Speed ​​​​change and turn obstacle avoidance left front obstacle critical safety distance Calculated by formula nine, formula nine is: ; is the minimum braking distance; is the speed of the obstacle in front of the left; Speed ​​Shift and Obstacle Avoidance Left Rear Obstacle Critical Safety Distance It is calculated by formula 10, which is: ; is the speed of the left rear obstacle.

8. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 7, characterized in that: Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated; Through formula 7, Through formula eight, According to formula nine, According to formula 10, when Calculated.

9. The multi-objective collaborative optimization obstacle avoidance behavior trajectory decision-making method according to claim 1, characterized in that: Construct safety evaluation index values ​​based on vehicle actual status information and safety threshold information , comfort evaluation index value , efficiency evaluation index value ; ; To avoid obstacles; Provides collision damage mitigation capabilities; Obstacle avoidance possibility; For speed change risk; ; is the actual distance between the vehicle and the obstacle in front; The critical safety distance between the vehicle and the obstacle in front at the initial moment of obstacle avoidance; when hour, , ; hour, , , , , ; The degree of collision damage mitigation is determined by the potential collision severity at the end of obstacle avoidance. The severity of potential collision at the initial moment of obstacle avoidance The difference is determined; is the initial speed of the vehicle; The equivalent speed at the moment of collision, which is determined by the vehicle's speed and posture at the time of collision; is the potential collision object speed; is the vehicle quality; is the mass of potential collision object; When the braking obstacle avoidance strategy is adopted, ; When using the steering obstacle avoidance strategy or the speed-changing steering obstacle avoidance strategy , , ; The actual distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The actual distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left front obstacle at the initial moment of obstacle avoidance; The critical safety distance between the vehicle and the left rear obstacle at the initial moment of obstacle avoidance; When adopting the braking obstacle avoidance strategy or the steering obstacle avoidance strategy, ; When the acceleration steering obstacle avoidance strategy is adopted, , , , , ; When the deceleration and steering obstacle avoidance strategy is adopted, , , , , ; is the target vehicle speed after the speed change; The minimum speed limit for the road; The maximum speed limit for the road; is the actual deceleration or acceleration; and Implementing boundary values ​​for distributed drive vehicles , ; ; is the maximum longitudinal acceleration during the obstacle avoidance process, is the maximum lateral acceleration during obstacle avoidance; is the longitudinal acceleration comfort threshold. , when using deceleration ; is the lateral acceleration comfort threshold, ; ; ; is the road reference speed; is the average vehicle speed during the obstacle avoidance process; When using the steering obstacle avoidance strategy, ; When using the braking obstacle avoidance strategy or the speed change steering obstacle avoidance strategy, ; The actual longitudinal distance traveled during the obstacle avoidance process; The total time consumption for obstacle avoidance is: ; When using the variable speed steering obstacle avoidance strategy, .

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