Vehicle control method and vehicle

Abstract

The present disclosure provides a vehicle control method and a vehicle, and relates to the technical field of unmanned driving. The method comprises the following steps: based on the trajectory information of key points in a planned trajectory and the current state information of a vehicle, determining the predicted roll information and the real-time roll information of the vehicle respectively. In the case that the predicted roll information or the real-time roll information meets a first preset condition, performing speed control on the vehicle according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information. Through the combination of the predicted roll information and the real-time roll information, the present disclosure realizes double roll risk assessment on the current driving condition of the vehicle and the key road section condition in front of the planned trajectory, effectively avoids the response lag problem existing in single real-time control, and greatly improves the real-time performance and reliability of the vehicle roll control.

Description

Technical Field

[0001] This disclosure relates to the field of autonomous driving technology, and in particular to a vehicle control method and a vehicle. Background Technology

[0002] The operating environment of unmanned vehicles is usually quite complex, with many unfavorable factors such as tilted, potholed roads and soft ground, which makes unmanned vehicles very prone to tilting accidents during operation.

[0003] To reduce the risk of rollover accidents, related technologies can assess and control the rollover risk of a vehicle based on its current driving status. However, this method has a significant time lag, making it difficult to predict and control impending rollover risks while an autonomous vehicle is traveling at high speed. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this disclosure provides a vehicle control method and a vehicle.

[0005] According to a first aspect of the present disclosure, a vehicle control method is provided, comprising:

[0006] Based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle, the predicted roll information and real-time roll information of the vehicle are determined respectively.

[0007] If the predicted roll information or the real-time roll information meets the first preset condition, the vehicle speed is controlled according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information.

[0008] In some embodiments, the predicted roll information includes a predicted roll index associated with the vehicle's current speed and trajectory information of key points; the real-time roll information includes a real-time roll index associated with the vehicle's current speed.

[0009] The predicted roll information or the real-time roll information satisfying the first preset condition includes:

[0010] The predicted roll index or the real-time roll index is greater than the first preset roll index threshold.

[0011] The predicted safe speed corresponding to the predicted roll information includes:

[0012] With the constraint that the predicted roll index does not exceed the first preset roll index threshold, a safe speed adapted to the driving conditions of key points is generated by combining the trajectory information of key points and the correlation between the predicted roll index and the vehicle speed.

[0013] The relationship between the predicted roll index and the vehicle speed is characterized by road curvature information, road slope information, and vehicle structural parameters at key points.

[0014] The current safe speed corresponding to the real-time roll information includes:

[0015] A safe speed adapted to the current driving conditions of the vehicle is generated by combining the vehicle's current state information and the correlation between the real-time roll index and the vehicle's driving speed, with the real-time roll index not exceeding the first preset roll index threshold as a constraint.

[0016] The relationship between the real-time roll index and the vehicle speed is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0017] In some embodiments, the predicted roll index is determined as follows:

[0018] The predicted lateral acceleration and road slope information at key points are input into a roll index model constructed based on vehicle structural parameters to obtain the predicted roll index; wherein, the predicted lateral acceleration is determined based on the vehicle's longitudinal velocity and the road curvature at key points.

[0019] The real-time roll index is determined in the following manner:

[0020] The vehicle's current lateral acceleration and road slope information at its current position are input into a roll index model constructed based on vehicle structural parameters to obtain the real-time roll index; wherein, the current lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate, and rate of change of lateral velocity.

[0021] The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration, and the roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0022] In some embodiments, the step of controlling the vehicle speed based on the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information includes:

[0023] The current safe speed of the vehicle is determined based on the real-time roll information, and the predicted safe speed of the vehicle is determined based on the predicted roll information.

[0024] If the current speed of the vehicle is detected to be greater than the first safe speed threshold for a preset number of frames, the desired speed of the vehicle is controlled to be the minimum of the current safe speed and the predicted safe speed.

[0025] The first safe speed threshold is determined by positively offsetting a preset first safe speed offset based on the minimum value.

[0026] In some embodiments, determining the current safe speed of the vehicle based on the real-time roll information includes:

[0027] Based on the vehicle's current state information, obtain the road slope information, lateral velocity change rate, and yaw rate of the vehicle's current position;

[0028] The road slope information, lateral velocity change rate, yaw rate, and pre-configured real-time roll index safety value at the current location are input into the pre-constructed real-time roll stability constraint equation to obtain the current safe speed.

[0029] The real-time roll stability constraint equation is obtained by substituting the current lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate, and lateral speed change rate, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The current safe speed is shown as the dependent variable of the adjusted roll index model, and the current safe speed is positively correlated with the real-time roll index safety value and negatively correlated with road slope information, lateral speed change rate, and yaw rate. The real-time roll index safety value satisfies the constraint condition of not exceeding a first preset roll index threshold.

[0030] Determining the predicted safe speed of the vehicle based on the predicted roll information includes:

[0031] Based on the trajectory information of key points, obtain the road curvature and road slope information at the key points;

[0032] The road curvature and slope information of key points, as well as the pre-configured predicted roll index safety value, are input into the pre-constructed predicted roll stability constraint equation to obtain the predicted safe speed.

[0033] The predicted roll stability constraint equation is obtained by substituting the predicted lateral acceleration, based on the vehicle's longitudinal speed and the road curvature at key points, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The predicted safe speed is shown as the dependent variable of the adjusted roll index model, and the predicted safe speed is positively correlated with the predicted roll index safety value and negatively correlated with road curvature and road slope information. The predicted roll index safety value satisfies the constraint condition of not exceeding a first preset roll index threshold.

[0034] In some embodiments, the method further includes:

[0035] If the vehicle's current speed is less than the second safe speed threshold or less than the preset second safe speed offset, then control of the desired speed will be terminated before reaching the next key point.

[0036] The second safe speed threshold is determined by offsetting a preset second safe speed offset from the minimum value.

[0037] In some embodiments, the number of key points is multiple, and the multiple key points are continuously distributed along the planned trajectory in the direction of vehicle travel. The road curvature corresponding to each key point is greater than a preset curvature threshold, and the distance between adjacent key points is less than a preset interval threshold.

[0038] The predicted roll information and real-time roll information of the vehicle are determined based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle, respectively, including:

[0039] Based on the trajectory information of multiple key points in the planned trajectory and the current state information of the vehicle, multiple predicted roll information corresponding to different key points and real-time roll information corresponding to the current position of the vehicle are determined respectively.

[0040] In some embodiments, the method further includes:

[0041] Based on the vehicle's current state information, determine the vehicle's steering roll information;

[0042] When the steering roll information meets the second preset condition, the steering angle of the vehicle is limited according to the safe steering angle corresponding to the steering roll information.

[0043] In some embodiments, the steering roll information includes: a steering roll index associated with the vehicle steering angle;

[0044] The safe steering angle corresponding to the steering roll information includes:

[0045] The safe steering angle is generated to suit the vehicle's driving conditions, taking into account the current state information of the vehicle and the correlation between the steering roll index and the vehicle steering angle, with the steering roll index not exceeding the second preset roll index threshold as a constraint.

[0046] The relationship between the steering roll index and the vehicle steering angle is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0047] The steering roll index is determined in the following manner:

[0048] The vehicle's steering lateral acceleration and the road slope information at the current position are input into a roll index model constructed based on vehicle structural parameters to obtain the steering roll index; wherein, the steering lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate gain and current steering angle;

[0049] The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration, and the roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0050] In some embodiments, the step of limiting the steering angle of the vehicle based on the safe steering angle corresponding to the steering roll information when the steering roll information meets a second preset condition includes:

[0051] When the steering roll index is greater than the second preset roll index threshold, the road slope information, longitudinal speed and yaw rate gain of the vehicle's current position are obtained based on the vehicle's current state information.

[0052] The road slope information, longitudinal speed, yaw rate gain, and pre-configured steering roll index safety value at the current location are input into a pre-constructed steering roll stability constraint equation to obtain the safe steering angle; the vehicle's steering angle is limited to not exceeding the safe steering angle.

[0053] The steering roll stability constraint equation is obtained by substituting the steering lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate gain, and steering angle, into the roll index model, and then adjusting the roll index model with the vehicle's steering angle as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The safe steering angle is shown as the dependent variable of the adjusted roll index model, and the current safe steering angle is positively correlated with the safe value of the steering roll index and negatively correlated with road slope information, longitudinal speed, and yaw rate gain. The safe value of the steering roll index satisfies the constraint condition of not exceeding the second preset roll index threshold.

[0054] According to a second aspect of this disclosure, a vehicle is provided, comprising:

[0055] Processor; and

[0056] Memory for storing the executable instructions of the processor;

[0057] The processor is configured to execute the method described in the first aspect by executing the executable instructions.

[0058] The solution provided in this disclosure can determine the predicted roll information and real-time roll information of the vehicle based on the trajectory information of key points in the planned trajectory and the vehicle's current state information, respectively. When either the predicted roll information or the real-time roll information meets a first preset condition, the vehicle speed is controlled according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information. By combining the predicted roll information and the real-time roll information, this disclosure achieves a dual roll risk assessment of the vehicle's current driving conditions and the conditions of key road sections ahead of the planned trajectory, effectively avoiding the response lag problem inherent in single real-time control and significantly improving the real-time performance and reliability of vehicle roll control. Attached Figure Description

[0059] Figure 1 A schematic flowchart of a vehicle control method according to an embodiment of this disclosure is shown.

[0060] Figure 2 A schematic diagram showing the relationship between the vehicle and the road cross slope angle in an embodiment of this disclosure is provided.

[0061] Figure 3 A flowchart illustrating a speed control method according to an embodiment of this disclosure is shown.

[0062] Figure 4 A flowchart illustrating a steering angle limiting method according to an embodiment of this disclosure is shown.

[0063] Figure 5 A schematic diagram of the structure of a vehicle control device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0064] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0065] First, this disclosure provides a vehicle control method that can be executed by any unmanned vehicle.

[0066] Figure 1 This diagram illustrates a flow chart of a vehicle control method according to an embodiment of the present disclosure, as shown below. Figure 1 As shown, the method includes the following steps S101 to S102.

[0067] S101, based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle, determines the predicted roll information and real-time roll information of the vehicle, respectively.

[0068] It should be noted that the planned trajectory can be pre-generated by the vehicle trajectory planning module based on information such as the driving task and road conditions, and is the driving trajectory that the vehicle needs to follow subsequently. Key points can be understood as pre-aimed feature points in the planned trajectory that are related to roll risk. Their trajectory information can include road parameters related to the vehicle's roll state, such as road curvature and road slope at the location of the key points.

[0069] The vehicle's current status information can be collected by various sensors on the vehicle, including parameters related to the vehicle's operating attitude, such as the vehicle's current lateral speed, longitudinal speed, yaw rate, and road slope at the current location.

[0070] In some embodiments, roll information can be understood as a quantitative representation of vehicle roll risk, which is a numerical representation of whether the vehicle roll state exceeds the safe range.

[0071] The predicted roll information is a forecast of the roll risk when the vehicle reaches a key point on the planned trajectory. It needs to be determined by combining the trajectory information of the key point and the vehicle's current state information, reflecting the roll risk of the key road section ahead in the vehicle's direction of travel. Real-time roll information is an immediate representation of the roll risk at the vehicle's current position, which can be determined based on the vehicle's current state information, reflecting the vehicle's current roll risk. This embodiment of the disclosure calculates both types of roll information separately to achieve a two-dimensional roll risk assessment for the vehicle's current driving stage and future aiming stage, providing a risk basis for triggering subsequent speed control.

[0072] S102, when the predicted roll information or real-time roll information meets the first preset condition, the vehicle speed is controlled according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information.

[0073] In some embodiments, the first preset condition may be a critical condition for triggering vehicle speed control, which matches the quantitative representation method of roll information. If the real-time roll information meets the first preset condition, it can be determined that the vehicle currently faces roll risk, requiring speed control to be triggered to reduce this risk. Similarly, if the predicted roll information meets the first preset condition, it can be determined that the vehicle will face roll risk when approaching a critical point ahead, again requiring speed control to attempt to avoid future roll risks.

[0074] For example, the predicted safe speed can be understood as the maximum permissible speed at which the vehicle will travel without exceeding the roll safety range when it reaches a key point on the planned trajectory. It can be determined by combining the predicted roll information with the trajectory information of the key point. The current safe speed is the maximum permissible speed at which the vehicle will travel without exceeding the roll safety range at its current driving position. It can be derived by combining the real-time roll information with the vehicle's current state information.

[0075] For example, after determining the predicted safe speed and the current safe speed, the ideal speed that balances vehicle driving efficiency and roll risk can be determined by combining the current safe speed and the predicted safe speed, and the actual driving speed of the vehicle can be controlled to not exceed this ideal speed. For instance, the minimum of the current safe speed and the predicted safe speed can be used as the aforementioned ideal speed, that is, the actual driving speed of the vehicle can be controlled to not exceed the minimum of the current safe speed and the predicted safe speed.

[0076] This disclosed embodiment can combine real-time roll information and predicted roll information to achieve a two-dimensional roll risk assessment of the vehicle's current driving conditions and the conditions of key road sections ahead of the planned trajectory. Furthermore, after determining that the vehicle has a roll risk, speed control can be applied to the vehicle by combining predicted safe speed and current safe speed. This allows speed regulation to simultaneously address both real-time response to current risks and proactive prevention of risks ahead, effectively solving the lag problem in roll control and improving the reliability of the control results.

[0077] The overall concept of this disclosure has been introduced above. It is understood that in the scheme provided in this disclosure, the selection of key points in the planned trajectory is closely related to the degree of proactive risk prevention and control. The selection method of key points in this application will be explained in detail below.

[0078] In some embodiments, key points can be selected at equal intervals, that is, key points are selected in the planned trajectory within a preset distance in front of the vehicle according to preset intervals.

[0079] The spacing and location of key points can be dynamically adjusted based on the vehicle's current longitudinal speed. For example, when the longitudinal speed is less than 30 km / h, the spacing between two adjacent key points is configured as 15m; when the longitudinal speed is greater than 30 km / h but less than 60 km / h, the spacing is configured as 30m; and when the longitudinal speed is greater than 60 km / h, the spacing is configured as 60m. After the spacing is determined, the planned trajectory within a preset distance ahead of the vehicle can be divided into evenly spaced sections according to the spacing, resulting in uniformly distributed key points. This allows the vehicle to predict the risk of lateral tilting in the road ahead in a timely manner, providing sufficient response time for speed control.

[0080] In some embodiments, key points can be selected based on their relevance to roll risk. For example, key point selection can be triggered when road characteristics meet preset road conditions. When the planned trajectory covers road segments with large curvature or cross slope angles, several key points are set at the start, end, and points of curvature abrupt change and / or maximum curvature, and points of cross slope abrupt change and / or maximum cross slope angle of such road segments. This approach allows roll risk prediction based on key points to be performed only when the vehicle is traveling through high-risk road segments, reducing unnecessary computation.

[0081] In some embodiments, basic key points can be set at equal intervals first, and then additional key points can be set for road sections that meet preset road conditions in the intervals between the basic key points. This allows for the prediction of global roll risk while focusing on high-risk road sections, thereby improving the accuracy of roll risk prediction for high-risk road sections.

[0082] By selecting key points using any of the methods provided in the above embodiments, one or more key points can be selected from the planned trajectory. It is worth noting that the number of key points selected is unrelated to the number of key points involved in determining the predicted roll information during a single vehicle control process. That is, even if multiple key points are pre-selected from the planned trajectory, only some key points may participate in determining the predicted roll information of the vehicle during a single execution of S101, rather than all of them.

[0083] Specifically, after pre-selecting multiple key points in the planned trajectory, the N key points closest to the vehicle or the N key points within a preset distance range in front of the vehicle can participate in the roll risk assessment and safe speed calculation. The remaining key points only complete the trajectory information extraction and temporary storage, and are gradually added to the assessment as the vehicle moves. Here, N is the number of key points participating in the calculation during one roll risk assessment process.

[0084] This configuration avoids the problem of excessive computational load caused by the simultaneous participation of a large number of key points, enabling the vehicle control method provided in this disclosure to adapt to the real-time computing needs of the vehicle controller.

[0085] For example, when there are multiple key points involved in executing the vehicle control method, when executing S101 above, multiple predicted roll information corresponding to different key points and real-time roll information corresponding to the current position of the vehicle can be determined based on the trajectory information of multiple key points in the planned trajectory and the current state information of the vehicle.

[0086] When executing S102 above, if any of the multiple predicted roll information or real-time roll information meets the first preset condition, the vehicle speed can be controlled according to the predicted safe speed corresponding to all the multiple predicted roll information and the current safe speed corresponding to the real-time roll information.

[0087] In other words, the predicted safe speed corresponding to each roll information can be determined separately, and the minimum value between each predicted safe speed and the current safe speed can be used as the vehicle's speed limit to control the vehicle's speed.

[0088] In some embodiments, when the vehicle is detected to be in a driving condition with a high risk of rollover, such as continuous cornering, the base speed limit can be reduced after obtaining the minimum value among the predicted safe speeds and the current safe speed (hereinafter referred to as the "base speed limit"), and used as the target speed limit of the vehicle to ensure safe driving of the vehicle in high-risk conditions.

[0089] For example, if multiple key points are detected that are continuously distributed along the planned trajectory in the vehicle's direction of travel, and the road curvature corresponding to each key point is greater than a preset curvature threshold, and the distance between adjacent key points is less than a preset interval threshold, it can be determined that the vehicle is in a driving condition with a high risk of rollover. Specifically, a continuously distributed road curvature with a large value indicates that the vehicle may be in a continuous curve-taking state, while the selection of key points with small intervals indicates that the driving environment of the road segment is relatively complex.

[0090] Specifically, continuous cornering can include continuous cornering in the same direction and continuous cornering in opposite directions.

[0091] Continuous same-direction cornering refers to the occurrence of multiple consecutive key points in the planned trajectory with the same road curvature direction and all road curvature exceeding a preset curvature threshold, and the distance between adjacent key points being less than a preset distance threshold. A typical continuous same-direction cornering section can be a mountain road, where vehicles continuously maintain the same steering state while driving on such road sections, resulting in a continuous accumulation of roll risks.

[0092] Continuous reverse cornering refers to key points in the planned trajectory where at least some road curvature directions are inconsistent and the road curvature is greater than a preset curvature threshold. There is no obvious straight transition section between key points where the curvature direction changes, and the distance between adjacent key points is less than a preset distance threshold. A typical continuous reverse cornering section can be an S-shaped curve. When vehicles pass through such sections, the steering direction changes rapidly, resulting in a rapid change in the direction of lateral acceleration and a high risk of roll.

[0093] Therefore, both continuous same-direction cornering and continuous reverse-direction cornering are high-risk driving conditions where the risk of body roll is continuous or changes rapidly, requiring further restrictions on the vehicle's speed limit.

[0094] For example, a preset safety factor can be set, and the product of the base speed limit and the safety factor can be used as the target speed limit under driving conditions with a high risk of rollover, so as to ensure the safety of vehicle driving.

[0095] For example, when the road curvature at some continuous key points is greater than the high-risk curvature threshold, the target speed limit of the vehicle can be directly configured to a preset fixed safe speed to cope with continuous cornering scenarios with large curvature and high risk.

[0096] For example, the speed limit can also be gradually reduced according to the gradient of curvature changes from small to large at multiple key points. The greater the curvature of a key point, the smaller the speed limit corresponding to that key point. This achieves gradient speed reduction as the risk of continuous cornering increases, matching the vehicle speed control with the changing trend of risk during continuous cornering. In this case, the target speed limit is the minimum value among the predicted safe speeds after gradient speed reduction and the current safe speed.

[0097] Next, the roll information and speed control methods involved in the embodiments of this disclosure will be introduced.

[0098] In some embodiments, the predicted roll information includes a predicted roll index associated with the vehicle’s current speed and trajectory information of key points.

[0099] The predicted roll index, as a quantitative representation parameter of predicted roll information, is a numerical assessment of the roll risk level when a vehicle reaches a critical point at its current speed. A higher value indicates a higher risk of rollover at that critical point. The higher the vehicle's current speed and the greater the curvature of the trajectory information at the critical point, the higher the predicted roll index value.

[0100] In some embodiments, the predicted roll index can be determined by inputting the predicted lateral acceleration and road slope information at key points into a roll index model constructed based on vehicle structural parameters to obtain the predicted roll index; wherein the predicted lateral acceleration is determined based on the vehicle's longitudinal velocity and the road curvature at key points.

[0101] For example, the predicted lateral acceleration can be understood as the estimated lateral acceleration when the vehicle reaches a critical point, which can be expressed by the following formula:

[0102]

[0103] in, Predicted lateral acceleration for key points. The vehicle's current longitudinal speed, The road radius at the key point. The road curvature at key points.

[0104] It is worth noting that since the location of the key point is relatively close to the current location of the vehicle, and the vehicle speed is usually relatively stable during normal driving and will not change abruptly in a short distance, the current longitudinal speed of the vehicle is actually approximated as the longitudinal speed of the vehicle when it will reach the key point in the future, in order to solve for the predicted lateral acceleration.

[0105] For example, in the above process of determining the predicted roll index, the roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration, and the roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0106] Specifically, the rollover index (RI) in this disclosure can be understood as the load transfer ratio (LTR) of the left and right tires of the vehicle, which can be characterized by the following formula:

[0107]

[0108] in, This refers to the load transfer rate between the left and right tires of the vehicle. The vertical load is on the left side of the vehicle. This refers to the vertical load on the right side of the vehicle.

[0109] For example, to apply the load transfer rate as a roll index to vehicle roll control, the dynamic characteristics of vehicle suspension roll and the elastic deformation of tires can be ignored during the calculation of the load transfer rate, while considering the influence of the road cross slope angle, resulting in the roll index representation shown in the following formula:

[0110]

[0111] in, The roll index, It is lateral acceleration. For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0112] Specifically, Figure 2 This diagram illustrates the relationship between the vehicle and the road cross slope angle in an embodiment of this disclosure. Figure 2 As shown, the road cross slope angle The angle of inclination of a road cross-section relative to the horizontal plane is a geometric property of the road itself. Furthermore, Figure 2In the coordinate system, y and z represent the horizontal and vertical directions in the ground coordinate system, respectively, and yb and zb represent the horizontal and vertical directions in the vehicle coordinate system, respectively. It can be seen that when the vehicle is in normal driving condition, the roll angle of the vehicle body is the same as the cross slope angle of the road. Therefore, the cross slope angle of the road can also show the attitude information of the vehicle and is directly related to the roll degree of the vehicle body.

[0113] The above formula is the roll index model in this embodiment of the disclosure. The larger the roll index output by the roll index model, the higher the risk of the vehicle rolling. Analysis of this model shows that... and All of these are determined by the vehicle's own geometric parameters. Since the acceleration due to gravity is constant, therefore , and All of them can be approximated as constants. This refers to the road cross slope angle (i.e., road gradient information), which is not controlled by the vehicle itself. Lateral acceleration can be controlled by adjusting the vehicle's own driving parameters.

[0114] It is evident that the roll index model actually reflects the roll index. With lateral acceleration and road cross slope angle The relationship between these factors is as follows: Lateral acceleration and road cross slope during vehicle movement cause body roll, leading to a redistribution of vertical loads on the left and right tires. Changes in the load transfer rate directly reflect the degree of body roll; a higher load transfer rate indicates a higher risk of rollover. The roll index model uses this mapping relationship to transform the abstract roll state into a quantifiable roll index value.

[0115] In other words, after calculating the predicted lateral acceleration, the predicted lateral acceleration is combined with the road cross slope angle and input into the above-mentioned roll index model to obtain the predicted roll index.

[0116] On the other hand, in solving the roll index Lateral acceleration during the process and road cross slope angle All are input values. However, due to the road cross slope angle... Since it is uncontrollable, when the roll index is high and the vehicle is at risk of roll, the lateral acceleration of the vehicle itself can be reduced. This reduces the roll index and prevents the vehicle from overturning.

[0117] In some embodiments, real-time roll information includes a real-time roll index associated with the vehicle’s current speed.

[0118] The real-time roll index, as a quantitative representation parameter of real-time roll information, is a numerical assessment of the actual roll risk level of a vehicle at its current position and speed. A higher value indicates a higher risk of rollover. The higher the vehicle's current speed, the higher the real-time roll index value.

[0119] In some embodiments, the real-time roll index is determined as follows: the vehicle's current lateral acceleration and road slope information at the current position are input into a roll index model constructed based on vehicle structural parameters to obtain the real-time roll index; wherein, the current lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate, and rate of change of lateral velocity.

[0120] For example, the current lateral acceleration can be understood as the lateral acceleration of the vehicle under its current operating conditions, which can be expressed by the following formula:

[0121]

[0122] in, The current lateral acceleration, The vehicle's current longitudinal speed, The yaw rate is angular velocity. This represents the rate of change of lateral velocity.

[0123] Regarding the roll index model in this embodiment, please refer to the description in the above embodiments, which will not be repeated here. After calculating the current lateral acceleration, the current lateral acceleration is combined with the road cross slope angle and input into the roll index model to obtain the current roll index.

[0124] In some embodiments, the predicted roll information or real-time roll information involved in S102 satisfying the first preset condition includes: the predicted roll index or real-time roll index being greater than the first preset roll index threshold.

[0125] As can be seen from the above, the larger the roll index, the greater the risk of vehicle roll. Therefore, if either the predicted roll index or the real-time roll index is greater than the first preset roll index threshold, it can be determined that the vehicle has a risk of roll and the speed control strategy will be triggered.

[0126] After the speed control strategy is triggered, a predicted safe speed corresponding to the predicted roll information and a current safe speed corresponding to the real-time roll information can be generated respectively, so as to determine the vehicle's speed limit based on the predicted safe speed and the current safe speed.

[0127] For example, the predicted safe speed corresponding to the predicted roll information (i.e., the predicted roll index) includes: a safe speed adapted to the driving conditions of key points, which is constrained by the predicted roll index not exceeding a first preset roll index threshold, combined with the trajectory information of key points and the correlation between the predicted roll index and the vehicle speed.

[0128] The relationship between the predicted roll index and vehicle speed is characterized by road curvature information, road slope information, and vehicle structural parameters at key points.

[0129] Specifically, referring to the relationship shown in the roll index model above, it can be seen that the predicted roll index is related to the predicted lateral acceleration at the key point. The predicted lateral acceleration can be represented by the vehicle's current longitudinal speed combined with the road curvature at the key point. Therefore, when using the roll index model to determine the predicted safe speed, it can be converted into a calculation model related to the vehicle's travel speed (longitudinal speed). This calculation model shows the correlation between the predicted roll index and the vehicle's travel speed. Furthermore, by constraining the predicted roll index in this calculation model, a safe speed can be generated when the predicted roll index does not exceed a first preset roll index threshold.

[0130] For example, the current safe speed corresponding to the real-time roll information (i.e., the real-time roll index) includes: a safe speed adapted to the current driving conditions of the vehicle, which is generated by combining the vehicle's current state information and the correlation between the real-time roll index and the vehicle's driving speed, with the real-time roll index not exceeding a first preset roll index threshold as a constraint.

[0131] The relationship between the real-time roll index and the vehicle speed is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0132] Specifically, referring to the relationship shown in the roll index model above, it can be seen that the current roll index is related to the current lateral acceleration. The current lateral acceleration can be represented by the vehicle's current longitudinal speed, yaw rate, and lateral speed change rate. Therefore, when the roll index model is used to determine the current safe speed, it can be converted into a calculation model related to the vehicle's travel speed (longitudinal speed). This calculation model is used to show the relationship between the current roll index and the vehicle's travel speed. Furthermore, by constraining the current roll index in this calculation model, a safe speed can be generated when the current roll index does not exceed a first preset roll index threshold.

[0133] As can be seen from the above embodiments, the first preset roll index threshold plays a role in two aspects in this application: firstly, it is used to determine whether the triggering conditions for vehicle speed control are met; secondly, it serves as a safety limit for the roll index dimension to solve for the safe speed.

[0134] Specifically, at the trigger condition determination level, this threshold defines a risk threshold for both the predicted roll index and the real-time roll index. If either index exceeds this threshold, the vehicle is deemed to have a current or anticipated rollover risk, triggering a speed control strategy. This method achieves accurate identification of roll risks in both dimensions and provides a clear basis for timely speed control intervention through quantitative values. At the safe speed calculation level, this threshold serves as a hard constraint. With the roll index not exceeding this threshold as the core premise, the current safe speed and the predicted safe speed are derived in reverse by combining trajectory information from key points and vehicle status information. This ensures that whether the vehicle is currently in its position or approaching a key point, the roll index remains within a safe range, fundamentally mitigating the risk of rollover.

[0135] Furthermore, the first preset roll index threshold is not fixed; it can be dynamically adjusted according to actual working conditions such as vehicle load, road adhesion coefficient, and vehicle structure, thereby adapting to the roll safety requirements of different driving scenarios.

[0136] Next, we will combine Figure 3 The speed control method in the embodiments of this disclosure will be described in detail. Figure 3 This diagram illustrates a flow chart of a speed control method according to an embodiment of the present disclosure, as shown below. Figure 3 As shown, the method includes the following steps S301 to S302.

[0137] S301 determines the vehicle's current safe speed based on real-time roll information and determines the vehicle's predicted safe speed based on predicted roll information.

[0138] For example, the current safe speed reflects the safe speed at which the vehicle's current roll index does not exceed a first preset roll index threshold. The predicted safe speed reflects the safe speed at which the predicted roll index does not exceed the first preset roll index threshold when the vehicle reaches a critical point. Both are solved using the first preset roll index threshold as a hard safety constraint, providing a precise and unified safe speed benchmark for subsequent speed control.

[0139] S302, if the current speed of the vehicle is detected to be greater than the first safe speed threshold continuously within a preset number of frames, the desired speed of the vehicle is controlled to be the minimum value between the current safe speed and the predicted safe speed.

[0140] The first safe speed threshold is determined by positively offsetting a preset first safe speed offset based on the minimum value between the current safe speed and the predicted safe speed.

[0141] For example, when determining whether to trigger speed control, the first safe speed threshold is not directly the minimum of the current safe speed and the predicted safe speed, but is obtained by positively offsetting a preset first safe speed offset from the minimum value. The core purpose of the positive offset is to set a safe buffer zone to avoid frequent control triggers caused by small fluctuations when the vehicle speed is close to the upper limit of the safe speed, thereby improving the smoothness of vehicle driving.

[0142] For similar reasons, this embodiment also sets a preset number of frames as a buffer during the judgment process. Only when the vehicle's current speed is continuously greater than the first safe speed threshold within the preset number of frames is the speed control trigger condition determined to be met, and subsequent desired speed adjustment is executed. By setting a first safe speed offset and a preset number of frames as a buffer, it avoids control erroneous triggering due to small speed fluctuations during vehicle operation, while ensuring timely intervention of control when the roll risk reaches a certain level, thus balancing the stability and safety of vehicle operation.

[0143] It is worth noting that in executing speed control, this embodiment uses the minimum of the current safe speed and the predicted safe speed as the control target for the vehicle's desired speed. The desired speed can be understood as the ideal target speed during vehicle operation, and it is the core instruction basis for the vehicle's powertrain control system to execute speed adjustment operations. By controlling the desired speed to the minimum of the current safe speed and the predicted safe speed, the vehicle can meet the more stringent roll safety constraint. Specifically, if the current safe speed is lower, it indicates a higher roll risk in the current driving condition, and control is prioritized according to the current safe speed to address the immediate roll risk; if the predicted safe speed is lower, it indicates a higher roll risk at the critical point ahead, and control is prioritized according to the predicted safe speed to achieve proactive roll risk control, thereby ensuring that the vehicle meets the roll index safety limit requirements whether it is currently in position or approaching a critical point ahead.

[0144] In some embodiments, if the vehicle's current speed is less than a second safe speed threshold or less than a preset second safe speed offset, then control of the desired speed is discontinued before reaching the next critical point.

[0145] The second safe speed threshold is determined by offsetting a preset second safe speed offset from the minimum of the current safe speed and the predicted safe speed.

[0146] Similar to the previous embodiment, to avoid frequent exits from desired speed control due to minor fluctuations, this embodiment also incorporates a second safe speed offset as an exit buffer in the threshold setting used to trigger the exit control judgment. Simultaneously, the reverse offset ensures that the vehicle speed is significantly lower than the safe speed limit when exiting desired speed control; that is, it exits control only after ensuring that the roll risk is completely eliminated, avoiding risk rebound caused by premature exiting control.

[0147] Furthermore, in setting the exit control judgment conditions, in addition to using the second safe speed threshold obtained after the reverse offset of the second safe speed as the judgment threshold, the second safe speed offset itself is also used as another judgment threshold. This is to avoid the minimum of the current safe speed and the predicted safe speed being too small, or the second safe speed offset being set too large, causing the minimum of the current safe speed and the predicted safe speed to become an assigned value after the reverse offset, resulting in an error in the judgment logic.

[0148] Based on the above judgment logic, after determining that the control exit condition is met, the controller will exit the hard upper limit control of the desired speed before the vehicle reaches the next key point, restore the vehicle's normal trajectory planning desired speed, and allow the vehicle to drive according to the speed requirement of the original planned trajectory. At the same time, it will maintain real-time monitoring of the roll index. If the trigger condition is met again, it will re-intervene in control.

[0149] In some embodiments, the current safe speed can be calculated as follows:

[0150] Based on the vehicle's current state information, obtain the road slope information, lateral velocity change rate, and yaw rate of the vehicle's current position;

[0151] Input the road slope information, lateral velocity change rate, yaw rate, and pre-configured real-time roll index safety value at the current location into the pre-constructed real-time roll stability constraint equation to obtain the current safe speed.

[0152] The real-time roll stability constraint equation is obtained by substituting the current lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate, and rate of change of lateral speed, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The current safe speed is shown as the dependent variable of the adjusted roll index model, and the current safe speed is positively correlated with the real-time roll index safety value, and negatively correlated with road slope information, lateral speed change rate, and yaw rate. The real-time roll index safety value meets the constraint condition of not exceeding the first preset roll index threshold.

[0153] Specifically, based on the roll index model described above, the real-time roll index can be characterized as:

[0154]

[0155] in, This is the real-time roll index. The current lateral acceleration, For the cross slope angle of the road, For the height of the vehicle's center of gravity, Vehicle equivalent track width This is the acceleration due to gravity.

[0156] The current lateral acceleration, characterized in the preceding text based on the vehicle's longitudinal velocity, yaw rate, and rate of change of lateral velocity, is obtained by... Substituting this into the above formula for calculating the real-time roll index, we can further obtain the following expression:

[0157]

[0158] in, This is the real-time roll index. The vehicle's current longitudinal speed, The yaw rate is angular velocity. The lateral velocity change rate, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0159] By controlling the longitudinal speed of the vehicle The above equation is adjusted using the longitudinal velocity as the dependent variable. Further, taking the current safe speed that needs to be solved, we can finally obtain the following formula:

[0160]

[0161] in, This is the current safe speed. This is the real-time roll index. The yaw rate is angular velocity. The lateral velocity change rate, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0162] This equation is the real-time roll stability constraint equation in this embodiment. When calculating the current safe speed, due to the real-time roll index... Since there is a constraint that the speed does not exceed the first preset roll index threshold, the first preset roll index threshold can be used as the real-time roll index safety value and substituted into the right side of the equation. This allows the current safe speed to be maximized while satisfying the roll index constraint, thus avoiding the impact on vehicle traffic efficiency due to an overly conservative current safe speed.

[0163] In some embodiments, the predicted safe speed can be calculated as follows:

[0164] Based on the trajectory information of key points, obtain the road curvature and road slope information at the key points;

[0165] By inputting the road curvature and slope information of key points, as well as the pre-configured predicted roll index safety value, into the pre-constructed predicted roll stability constraint equation, the predicted safe speed is obtained.

[0166] The predicted roll stability constraint equation is obtained by substituting the predicted lateral acceleration, which is based on the vehicle's longitudinal speed and the road curvature at key points, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The predicted safe speed is shown through the dependent variable of the adjusted roll index model, and the predicted safe speed is positively correlated with the predicted roll index safety value and negatively correlated with the road curvature and road slope information. The predicted roll index safety value satisfies the constraint condition of not exceeding the first preset roll index threshold.

[0167] Specifically, based on the roll index model described above, the predicted roll index can be characterized as follows:

[0168]

[0169] in, To predict the roll index, To predict lateral acceleration, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0170] The predicted lateral acceleration is obtained by using the vehicle's longitudinal velocity and the road curvature characterization at key points as described above. Substituting these values ​​into the formula for calculating the predicted tilt index, we can further obtain the following expression:

[0171]

[0172] in, To predict the roll index, The vehicle's current longitudinal speed, The road curvature at key points For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0173] By controlling the longitudinal speed of the vehicle The above equation is adjusted using the longitudinal velocity as the dependent variable. Further, considering the predicted safety speed that needs to be solved, we can finally obtain the following formula:

[0174]

[0175] in, That is, to predict the safe speed. To predict the roll index, The road curvature at key points For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. Let gravitational acceleration be denoted as . This equation is the predicted roll stability constraint equation in this embodiment. When calculating the predicted safe speed, the predicted roll index is used... Since there is a constraint that the speed does not exceed the first preset roll index threshold, the first preset roll index threshold can be used as the predicted roll index safety value and substituted into the right side of the equation. This allows the predicted safe speed to be maximized while satisfying the roll index constraint, thus avoiding the impact on vehicle traffic efficiency due to an overly conservative predicted safe speed.

[0176] As can be seen from the above embodiments, this disclosure provides a comprehensive speed control system to reduce vehicle roll risk. Firstly, by setting judgment conditions including a continuous preset number of frames and a positive offset, a buffer zone is provided for the initiation of speed control, avoiding false triggering of control caused by instantaneous fluctuations in the roll index, thus balancing control timeliness and driving smoothness. After determining that speed control is triggered, the current safe speed and predicted safe speed of the vehicle are calculated using a roll stability constraint equation derived in reverse from the roll index model. The minimum of the current safe speed and the predicted safe speed is used as the upper limit of the vehicle's desired speed, ensuring that speed regulation simultaneously meets the dual safety constraints of current real-time roll risk and forward predicted roll risk. Simultaneously, this disclosure also adaptively sets a second safe speed threshold with a reverse offset and a speed control exit condition for low-speed exemption, defining clear and safe judgment criteria for the release of speed control, ensuring that control is only released after the roll risk is completely eliminated, and avoiding risk rebound. Based on this, the initiation, execution and deactivation of speed control in this embodiment form a complete closed loop, which effectively improves the accuracy and reliability of rollover risk prevention and control, and achieves a triple balance of rollover prevention, ride comfort and driving efficiency.

[0177] In some embodiments, when the roll index is too high, in addition to controlling the vehicle speed, the vehicle's steering angle can also be limited to prevent the vehicle from rolling.

[0178] Specifically, please refer to Figure 4 , Figure 4 This diagram illustrates a flowchart of a steering angle limiting method provided by an embodiment of the present disclosure, which can be executed by any unmanned vehicle. Figure 4 As shown, the method includes the following steps S401 to S402.

[0179] S401 determines the vehicle's steering roll information based on the vehicle's current state information.

[0180] For example, steering roll information is a parameter used to characterize the roll risk of a vehicle due to its own steering actions. Unlike predictive roll information and real-time roll information, which characterize the roll risk of a vehicle from the dimension of speed, steering roll information characterizes the measured roll risk from the dimension of the vehicle's steering angle. It focuses more on the body roll and tire load offset risks directly caused by steering operations, and is an independent assessment of the roll risk of the vehicle under steering conditions.

[0181] S402, when the steering roll information meets the second preset condition, the vehicle's steering angle is limited according to the safe steering angle corresponding to the steering roll information.

[0182] For example, the second preset condition is a critical judgment criterion for triggering the steering angle limit. When the steering roll information meets the second preset condition, it indicates that the vehicle currently has a high risk of roll. At this time, in addition to speed control, the vehicle's steering angle also needs to be limited to avoid the vehicle from overturning.

[0183] For example, when the second preset condition is met, the controller will limit the vehicle's actual steering angle to within a safe steering angle, prohibiting the vehicle's actual steering angle from exceeding the safe steering angle, thereby reducing the vehicle's roll risk. The safe steering angle can be understood as the maximum permissible steering angle when the vehicle's steering roll information is within a safe range under the current operating conditions.

[0184] Based on vehicle speed control, this disclosure supplements the assessment and prevention of roll risk from the perspective of steering limitation, which can specifically reduce the roll risk caused by vehicle oversteering.

[0185] In some embodiments, steering roll information can be quantified as a steering roll index associated with the vehicle's steering angle. The magnitude of the steering roll index is positively correlated with the vehicle's steering angle and speed; the greater the steering angle and the faster the vehicle speed, the greater the steering roll index, and the higher the risk of the vehicle rolling over due to steering.

[0186] Specifically, the steering roll index is determined as follows:

[0187] The vehicle's steering lateral acceleration and the road slope information at the current position are input into a roll index model constructed based on vehicle structural parameters to obtain the steering roll index; wherein, the steering lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate gain and current steering angle.

[0188] The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of a vehicle and the lateral acceleration. The roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0189] For example, steering lateral acceleration can be understood as lateral acceleration characterized by the vehicle's steering angle, which can be expressed by the following formula:

[0190]

[0191] in, For steering lateral acceleration, The vehicle's current longitudinal speed, The yaw rate is angular velocity. The rate of change of the centroid sideslip angle. This is the steering angle of the vehicle's front wheels. This is the yaw rate gain.

[0192] It can be represented as:

[0193]

[0194] in, For yaw rate gain, This refers to the vehicle's wheelbase. The vehicle's current longitudinal speed, The total mass of the vehicle. This is the distance from the vehicle's center of gravity to the rear axle. For the front axle tire lateral stiffness, This is the distance from the vehicle's center of gravity to the front axle. This refers to the lateral stiffness of the rear axle tires.

[0195] In practical applications, It can be further simplified to:

[0196]

[0197] in, For yaw rate gain, This refers to the vehicle's wheelbase. The vehicle's current longitudinal speed, Characteristic vehicle speed.

[0198] Regarding the roll index model in this embodiment, please refer to the description in the above embodiments; this disclosure will not repeat it further. After calculating the steering lateral acceleration, the steering lateral acceleration is combined with the road cross slope angle and input into the roll index model to obtain the steering roll index.

[0199] Accordingly, the safe steering angle corresponding to the steering roll information (i.e., the steering roll index) includes: a safe steering angle adapted to the vehicle's driving conditions, which is generated by combining the vehicle's current state information and the correlation between the steering roll index and the vehicle's steering angle, with the steering roll index not exceeding the second preset roll index threshold as a constraint.

[0200] The relationship between the steering roll index and the vehicle steering angle is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0201] Specifically, referring again to the relationship shown in the roll index model, it can be seen that when the roll index model is applied to characterize the steering roll index, the steering roll index is related to the steering lateral acceleration. The steering lateral acceleration can be represented by the vehicle's steering angle combined with the current longitudinal velocity and yaw rate gain. Therefore, when the aforementioned roll index model is used to determine the safe steering angle, it can be converted into a calculation model related to the vehicle's steering angle. This calculation model shows the correlation between the steering roll index and the vehicle's steering angle. Furthermore, by constraining the steering roll index in this calculation model, a safe steering angle can be generated when the steering roll index does not exceed a second preset roll index threshold.

[0202] In some embodiments, the above S402 can be specifically described as:

[0203] When the steering roll index is greater than the second preset roll index threshold, the road slope information, longitudinal speed and yaw rate gain of the vehicle's current position are obtained based on the vehicle's current state information.

[0204] The road slope information, longitudinal speed, yaw rate gain, and pre-configured steering roll index safety value at the current location are input into the pre-constructed steering roll stability constraint equation to obtain the safe steering angle; wherein, the vehicle's steering angle is limited to not exceeding the safe steering angle.

[0205] The steering roll stability constraint equation is obtained by substituting the steering lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate gain, and steering angle, into the roll index model, and then adjusting the roll index model with the vehicle's steering angle as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The safe steering angle is shown as the dependent variable of the adjusted roll index model, and the current safe steering angle is positively correlated with the safe value of the steering roll index, and negatively correlated with road slope information, longitudinal speed, and yaw rate gain. The safe value of the steering roll index meets the constraint condition of not exceeding the second preset roll index threshold.

[0206] Specifically, according to the roll index model described above, the steering roll index can be characterized as:

[0207]

[0208] in, This refers to the steering roll index. For steering lateral acceleration, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0209] The steering lateral acceleration, characterized by the vehicle's longitudinal velocity, yaw rate gain, and steering angle as described above, is... Substituting these values ​​into the formula for calculating the steering roll index, we can further obtain the following expression:

[0210]

[0211] in, This refers to the steering roll index. The vehicle's current longitudinal speed, This is the steering angle of the vehicle's front wheels. For yaw rate gain, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity.

[0212] By adjusting the vehicle's steering angle Adjust the above equation as the dependent variable, and then use the steering angle after adjustment. Further, as the safety steering angle that needs to be solved, we can finally obtain the following formula:

[0213]

[0214] in, This is the safe steering angle. This refers to the steering roll index. The vehicle's current longitudinal speed, For yaw rate gain, For the cross slope angle of the road, For the height of the vehicle's center of gravity, The equivalent wheelbase of the vehicle. This is the acceleration due to gravity. This equation is the steering roll stability constraint equation in this embodiment. When calculating the safe steering angle, due to the steering roll index... Since there is a constraint that the safe steering angle does not exceed the second preset roll index threshold, the second preset roll index threshold can be substituted into the right side of the equation as the safe value of the steering roll index. This allows the obtained safe steering angle to be maximized while satisfying the roll index constraint, thus avoiding the impact on vehicle traffic efficiency due to an overly conservative safe steering angle.

[0215] The second preset roll index threshold is greater than the first preset roll index threshold.

[0216] This disclosed embodiment extends vehicle speed control to vehicle steering limitation in scenarios with high roll risk. The two control schemes work together to avoid blind spots in single-dimensional control. Specifically, the vehicle steering limitation effectively addresses the instantaneous roll hazard caused by steering operations during sharp turns and continuous cornering, while maximizing vehicle handling agility while ensuring safety. Combined with speed control, this significantly improves driving stability and rollover prevention capabilities under complex conditions.

[0217] Based on the same inventive concept, this disclosure also provides a vehicle control device, as shown in the following embodiment. Since the principle of this vehicle control device embodiment in solving the problem is the same as that described above... Figure 1 The method embodiments shown are similar, therefore, the implementation of this vehicle control device embodiment can refer to the above. Figure 1 The implementation of the method embodiments shown will not be repeated here.

[0218] Figure 5 A schematic diagram of the structure of a vehicle control device according to an embodiment of this disclosure is shown. Figure 5 As shown, the vehicle control device 500 includes a determination module 501 and a control module 502.

[0219] The determination module 501 is used to determine the predicted roll information and real-time roll information of the vehicle based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle.

[0220] The control module 502 is used to control the vehicle speed according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information when the predicted roll information or the real-time roll information meets the first preset condition.

[0221] In some embodiments, the predicted roll information includes a predicted roll index associated with the vehicle’s current speed and trajectory information of key points; the real-time roll information includes a real-time roll index associated with the vehicle’s current speed.

[0222] Predicted roll information or real-time roll information meeting the first preset condition includes:

[0223] The predicted roll index or the real-time roll index is greater than the first preset roll index threshold.

[0224] The predicted safe speed corresponding to the predicted roll information includes:

[0225] With the constraint that the predicted roll index does not exceed the first preset roll index threshold, a safe speed adapted to the driving conditions of key points is generated by combining the trajectory information of key points and the correlation between the predicted roll index and the vehicle speed.

[0226] The relationship between the predicted roll index and vehicle speed is characterized by road curvature information, road slope information, and vehicle structural parameters at key points.

[0227] The current safe speed corresponding to the real-time roll information includes:

[0228] A safe speed adapted to the current driving conditions of the vehicle is generated by combining the vehicle's current state information and the correlation between the real-time roll index and the vehicle's driving speed, with the real-time roll index not exceeding the first preset roll index threshold as a constraint.

[0229] The relationship between the real-time roll index and the vehicle speed is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0230] In some embodiments, the predicted roll index is determined as follows:

[0231] The predicted lateral acceleration and road slope information at key points are input into a roll index model constructed based on vehicle structural parameters to obtain the predicted roll index; wherein, the predicted lateral acceleration is determined based on the vehicle's longitudinal velocity and the road curvature at key points.

[0232] The real-time roll index is determined as follows:

[0233] The vehicle's current lateral acceleration and road slope information at its current position are input into a roll index model constructed based on vehicle structural parameters to obtain the real-time roll index; where the current lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate, and rate of change of lateral velocity.

[0234] The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of a vehicle and the lateral acceleration. The roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0235] In some embodiments, the control module 502 is configured to determine the current safe speed of the vehicle based on real-time roll information and to determine the predicted safe speed of the vehicle based on predicted roll information.

[0236] If the vehicle's current speed is detected to be greater than the first safe speed threshold for a preset number of frames, the vehicle's desired speed will be controlled to the minimum of the current safe speed and the predicted safe speed.

[0237] The first safe speed threshold is determined by positively offsetting a preset first safe speed offset from the minimum value.

[0238] In some embodiments, the control module 502 is used to obtain road slope information, lateral velocity change rate and yaw rate of the vehicle's current position based on the vehicle's current state information.

[0239] Input the road slope information, lateral velocity change rate, yaw rate, and pre-configured real-time roll index safety value at the current location into the pre-constructed real-time roll stability constraint equation to obtain the current safe speed.

[0240] The real-time roll stability constraint equation is obtained by substituting the current lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate, and rate of change of lateral speed, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The current safe speed is shown as the dependent variable of the adjusted roll index model, and the current safe speed is positively correlated with the real-time roll index safety value, and negatively correlated with road slope information, lateral speed change rate, and yaw rate. The real-time roll index safety value meets the constraint condition of not exceeding the first preset roll index threshold.

[0241] In some embodiments, the control module 502 is used to obtain road curvature and road slope information at key points based on the trajectory information of key points;

[0242] By inputting the road curvature and road slope information of key points, as well as the pre-configured predicted roll index safety value, into the pre-constructed predicted roll stability constraint equation, the predicted safe speed is obtained.

[0243] The real-time roll stability constraint equation is obtained by substituting the predicted lateral acceleration, based on the vehicle's longitudinal velocity and the road curvature at key points, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal velocity as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The predicted safe speed is shown through the dependent variable of the adjusted roll index model, and the predicted safe speed is positively correlated with the predicted roll index safety value and negatively correlated with the road curvature and road slope information. The predicted roll index safety value satisfies the constraint condition of not exceeding the first preset roll index threshold.

[0244] In some embodiments, the control module 502 is configured to exit control of the desired speed before reaching the next key point if the current speed of the vehicle is less than a second safe speed threshold or less than a preset second safe speed offset.

[0245] The second safe speed threshold is determined by offsetting a preset second safe speed offset from the minimum value.

[0246] In some embodiments, there are multiple key points, which are continuously distributed along the planned trajectory in the vehicle's driving direction. The road curvature corresponding to each key point is greater than a preset curvature threshold, and the distance between adjacent key points is less than a preset interval threshold. The determining module 501 is used to determine multiple predicted tilt information corresponding to different key points and real-time tilt information corresponding to the vehicle's current position, based on the trajectory information of multiple key points in the planned trajectory and the vehicle's current state information.

[0247] In some embodiments, the determining module 501 is further configured to determine the vehicle's steering roll information based on the vehicle's current state information. The control module 502 is further configured to limit the vehicle's steering angle according to the safe steering angle corresponding to the steering roll information when the steering roll information meets a second preset condition.

[0248] In some embodiments, steering roll information includes: a steering roll index associated with the vehicle steering angle;

[0249] The safe steering angle corresponding to the steering roll information includes:

[0250] The safe steering angle is generated to suit the vehicle's driving conditions, taking into account the current state information of the vehicle and the correlation between the steering roll index and the vehicle steering angle, with the steering roll index not exceeding the second preset roll index threshold as a constraint.

[0251] The relationship between the steering roll index and the vehicle steering angle is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

[0252] The steering roll index is determined as follows:

[0253] The vehicle's steering lateral acceleration and the road slope information at the current position are input into a roll index model constructed based on vehicle structural parameters to obtain the steering roll index; wherein, the steering lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate gain and current steering angle.

[0254] The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of a vehicle and the lateral acceleration. The roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

[0255] In some embodiments, the control module 502 is used to obtain road slope information, longitudinal speed and yaw rate gain of the vehicle's current position based on the vehicle's current state information when the steering roll index is greater than a second preset roll index threshold.

[0256] Input the road slope information, longitudinal speed, yaw rate gain, and pre-configured steering roll index safety value at the current location into the pre-constructed steering roll stability constraint equation to obtain the safe steering angle.

[0257] The vehicle's steering angle is limited to no more than a safe steering angle;

[0258] The steering roll stability constraint equation is obtained by substituting the steering lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate gain, and steering angle, into the roll index model, and then adjusting the roll index model with the vehicle's steering angle as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The safe steering angle is shown as the dependent variable of the adjusted roll index model, and the current safe steering angle is positively correlated with the safe value of the steering roll index, and negatively correlated with road slope information, longitudinal speed, and yaw rate gain. The safe value of the steering roll index meets the constraint condition of not exceeding the second preset roll index threshold.

[0259] Based on the same inventive concept, this disclosure also provides an unmanned vehicle, including:

[0260] Processor; and

[0261] Memory for storing the executable instructions of the processor;

[0262] The processor is configured to execute the vehicle control method described above by executing the executable instructions.

[0263] In some embodiments, this disclosure also provides a computer-readable storage medium, which may be a readable signal medium or a readable storage medium. A program product capable of implementing the methods described above is stored thereon. In some possible embodiments, various aspects of this disclosure may also be implemented as a program product including program code, which, when run on a terminal device, causes the terminal device to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure.

[0264] In some embodiments, this disclosure also provides a computer program product, including a computer program that, when executed by a controller, implements the steps of the vehicle control method described above.

[0265] These computer programs or instructions can be applied to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device, enabling the processor of the general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to function as an apparatus for implementing the corresponding functions in the above method embodiments.

[0266] Furthermore, the specific implementation form of the computer program product is not limited in the embodiments of this application. In some embodiments, the computer program product may be implemented as an application (APP), a mini-program, a PC client, a program module, a plug-in, an installation package, a software development kit (SDK), an image file of an optical disc (such as an ISO file), a plug-in, or software in the form of Software as a Service (SaaS), etc., but is not limited to these.

[0267] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A vehicle control method, characterized in that, include: Based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle, the predicted roll information and real-time roll information of the vehicle are determined respectively; wherein, the predicted roll information includes: a predicted roll index associated with the current speed of the vehicle and the trajectory information of key points; the real-time roll information includes: a real-time roll index associated with the current speed of the vehicle. If the predicted roll information or the real-time roll information is greater than a first preset roll index threshold, the vehicle speed is controlled according to the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information. The method further includes: Based on the vehicle's current state information, determine the steering roll index associated with the vehicle's steering angle; When the steering roll index meets the second preset condition, the steering angle of the vehicle is limited according to the safe steering angle corresponding to the steering roll index; the safe steering angle includes: a safe steering angle adapted to the vehicle driving conditions, which is constrained by the steering roll index not exceeding the second preset roll index threshold, combined with the current state information of the vehicle and the correlation between the steering roll index and the vehicle steering angle. The relationship between the steering roll index and the vehicle steering angle is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

2. The method according to claim 1, characterized in that, The predicted safe speed corresponding to the predicted roll information includes: With the constraint that the predicted roll index does not exceed the first preset roll index threshold, a safe speed adapted to the driving conditions of key points is generated by combining the trajectory information of key points and the correlation between the predicted roll index and the vehicle speed. The relationship between the predicted roll index and the vehicle speed is characterized by road curvature information, road slope information, and vehicle structural parameters at key points. The current safe speed corresponding to the real-time roll information includes: A safe speed adapted to the current driving conditions of the vehicle is generated by combining the vehicle's current state information and the correlation between the real-time roll index and the vehicle's driving speed, with the real-time roll index not exceeding the first preset roll index threshold as a constraint. The relationship between the real-time roll index and the vehicle speed is characterized by the vehicle's current motion state information, road slope information, and vehicle structural parameters.

3. The method according to claim 2, characterized in that, The predicted roll index is determined in the following manner: The predicted lateral acceleration and road slope information at key points are input into a roll index model constructed based on vehicle structural parameters to obtain the predicted roll index; wherein, the predicted lateral acceleration is determined based on the vehicle's longitudinal velocity and the road curvature at key points. The real-time roll index is determined in the following manner: The vehicle's current lateral acceleration and road slope information at its current position are input into a roll index model constructed based on vehicle structural parameters to obtain the real-time roll index; wherein, the current lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate, and rate of change of lateral velocity. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration, and the roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

4. The method according to any one of claims 1 to 3, characterized in that, The step of controlling the vehicle speed based on the predicted safe speed corresponding to the predicted roll information and the current safe speed corresponding to the real-time roll information includes: The current safe speed of the vehicle is determined based on the real-time roll information, and the predicted safe speed of the vehicle is determined based on the predicted roll information. If the current speed of the vehicle is detected to be greater than the first safe speed threshold for a preset number of frames, the desired speed of the vehicle is controlled to be the minimum of the current safe speed and the predicted safe speed. The first safe speed threshold is determined by positively offsetting a preset first safe speed offset based on the minimum value.

5. The method according to claim 4, characterized in that, Determining the vehicle's current safe speed based on the real-time roll information includes: Based on the vehicle's current state information, obtain the road slope information, lateral velocity change rate, and yaw rate of the vehicle's current position; The road slope information, lateral velocity change rate, yaw rate, and pre-configured real-time roll index safety value at the current location are input into the pre-constructed real-time roll stability constraint equation to obtain the current safe speed. The real-time roll stability constraint equation is obtained by substituting the current lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate, and lateral speed change rate, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The current safe speed is shown as the dependent variable of the adjusted roll index model, and the current safe speed is positively correlated with the real-time roll index safety value and negatively correlated with road slope information, lateral speed change rate, and yaw rate. The real-time roll index safety value satisfies the constraint condition of not exceeding a first preset roll index threshold. Determining the predicted safe speed of the vehicle based on the predicted roll information includes: Based on the trajectory information of key points, obtain the road curvature and road slope information at the key points; The road curvature and slope information of key points, as well as the pre-configured predicted roll index safety value, are input into the pre-constructed predicted roll stability constraint equation to obtain the predicted safe speed. The predicted roll stability constraint equation is obtained by substituting the predicted lateral acceleration, based on the vehicle's longitudinal speed and the road curvature at key points, into the roll index model, and then adjusting the roll index model with the vehicle's longitudinal speed as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The predicted safe speed is shown as the dependent variable of the adjusted roll index model, and the predicted safe speed is positively correlated with the predicted roll index safety value and negatively correlated with road curvature and road slope information. The predicted roll index safety value satisfies the constraint condition of not exceeding a first preset roll index threshold.

6. The method according to claim 4, characterized in that, The method further includes: If the vehicle's current speed is less than the second safe speed threshold or less than the preset second safe speed offset, then control of the desired speed will be terminated before reaching the next key point. The second safe speed threshold is determined by offsetting a preset second safe speed offset from the minimum value.

7. The method according to claim 1, characterized in that, The number of key points is multiple, and the multiple key points are continuously distributed along the planned trajectory in the direction of vehicle travel. The road curvature corresponding to each key point is greater than a preset curvature threshold, and the distance between adjacent key points is less than a preset interval threshold. The predicted roll information and real-time roll information of the vehicle are determined based on the trajectory information of key points in the planned trajectory and the current state information of the vehicle, respectively, including: Based on the trajectory information of multiple key points in the planned trajectory and the current state information of the vehicle, multiple predicted roll information corresponding to different key points and real-time roll information corresponding to the current position of the vehicle are determined respectively.

8. The method according to claim 1, characterized in that, The steering roll index is determined in the following manner: The vehicle's steering lateral acceleration and the road slope information at the current position are input into a roll index model constructed based on vehicle structural parameters to obtain the steering roll index; wherein, the steering lateral acceleration is determined based on the vehicle's longitudinal velocity, yaw rate gain and current steering angle; The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration, and the roll index output by the roll index model is positively correlated with the input lateral acceleration and road slope information.

9. The method according to claim 8, characterized in that, The step of limiting the steering angle of the vehicle based on the safe steering angle corresponding to the steering roll index when the steering roll index meets the second preset condition includes: When the steering roll index is greater than the second preset roll index threshold, the road slope information, longitudinal speed and yaw rate gain of the vehicle's current position are obtained based on the vehicle's current state information. The road slope information, longitudinal speed, yaw rate gain, and pre-configured steering roll index safety value at the current location are input into a pre-constructed steering roll stability constraint equation to obtain the safe steering angle; the vehicle's steering angle is limited to not exceeding the safe steering angle. The steering roll stability constraint equation is obtained by substituting the steering lateral acceleration, characterized by the vehicle's longitudinal speed, yaw rate gain, and steering angle, into the roll index model, and then adjusting the roll index model with the vehicle's steering angle as the dependent variable. The roll index model is used to characterize the mapping relationship between the load transfer rate of the left and right tires of the vehicle and the lateral acceleration. The safe steering angle is shown as the dependent variable of the adjusted roll index model, and the current safe steering angle is positively correlated with the safe value of the steering roll index and negatively correlated with road slope information, longitudinal speed, and yaw rate gain. The safe value of the steering roll index satisfies the constraint condition of not exceeding the second preset roll index threshold.

10. A vehicle, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the method of any one of claims 1 to 9 by executing the executable instructions.

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