An obstacle avoidance control method and terminal for unmanned vehicles

Abstract

This invention provides an obstacle avoidance control method and terminal for unmanned vehicles. The obstacle avoidance method includes: detecting obstacles; determining the obstacle avoidance zone to which the obstacle belongs based on its location information; classifying obstacles according to their respective obstacle avoidance zones, with higher priority zones closer to the vehicle; determining the highest priority obstacle; and executing the obstacle avoidance strategy corresponding to the highest priority obstacle. The obstacle avoidance zone is configured by first determining the vehicle's operating mode, extracting operating parameters, and defining the obstacle avoidance strategy based on these parameters. The obstacle avoidance strategy is configured to correspond to different obstacle avoidance zones. This invention predefines the one-to-one correspondence between the vehicle's operating state and obstacle avoidance zones, and pre-defines the obstacle avoidance strategy corresponding to each zone. By classifying obstacles according to their respective zones, only the highest priority obstacle needs to be determined to establish the corresponding obstacle avoidance strategy. This hierarchical management and control is more adaptable to application scenarios with many obstacles, resulting in faster processing speed and higher efficiency.

Description

Technical Field

[0001] This invention belongs to the field of autonomous driving technology for unmanned vehicles, and particularly relates to an obstacle avoidance control method and terminal for unmanned vehicles. Background Technology

[0002] With the development of industrial automation, guided vehicles, such as unmanned vehicles, are a common type of industrial handling vehicle. They are often used for loading, unloading, and short-distance transportation of palletized goods and are widely used in ports, stations, airports, freight yards, factory workshops, warehouses, and other places.

[0003] Under the control of algorithms, autonomous vehicles travel along planned routes and complete tasks such as picking up and placing goods. However, due to the complexity of the workplace, autonomous vehicles can easily accidentally enter other objects in the driving area. If the autonomous vehicle does not plan to avoid other objects in advance, there is often a risk of accidents due to untimely avoidance. On the other hand, the planned routes of autonomous vehicles often include multiple straight lines and curves. How to achieve fast and effective obstacle avoidance based on the driving route conditions and the vehicle's own operating status is of great significance in the field of autonomous driving. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an unmanned vehicle obstacle avoidance control method and terminal, which is mainly used to solve the problem of poor obstacle avoidance effect of unmanned vehicles in the prior art.

[0005] To achieve the above objectives, in a first aspect, the present invention provides an obstacle avoidance control method for unmanned vehicles, used for the automatic driving of unmanned vehicles, comprising the following steps:

[0006] The system detects obstacles, determines their corresponding obstacle avoidance zones based on their location information, and classifies obstacles according to their respective obstacle avoidance zones, with higher priority given to obstacle avoidance zones that are closer to the vehicle.

[0007] Determine the highest priority detected obstacle and execute the obstacle avoidance strategy for the corresponding obstacle avoidance zone;

[0008] The obstacle avoidance zone is configured to first determine the vehicle's operating mode, extract operating parameters, and define the obstacle avoidance strategy according to the operating parameters; the obstacle avoidance strategy is configured to be formulated according to different obstacle avoidance zones.

[0009] Furthermore, the obstacle avoidance zone includes, from the inside out, an emergency obstacle avoidance zone, an inner obstacle avoidance zone, and an outer obstacle avoidance zone. The area of ​​the area included by the emergency obstacle avoidance zone, the inner obstacle avoidance zone, and the outer obstacle avoidance zone gradually increases. The area of ​​the obstacle avoidance zone changes with the operating parameters of the vehicle. Each obstacle avoidance zone includes a front obstacle avoidance zone in front of the vehicle and side obstacle avoidance zones on both sides of the vehicle.

[0010] Furthermore, the obstacle avoidance strategy corresponding to the emergency obstacle avoidance zone is as follows:

[0011] Determine the vehicle's current speed and / or distance from obstacles;

[0012] When the vehicle's current operating speed is greater than the emergency obstacle avoidance speed setting value, and / or the distance between the vehicle and the obstacle is less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to apply the emergency brake.

[0013] When the vehicle's current operating speed is not greater than the emergency obstacle avoidance speed setting value, and the distance between the vehicle and the obstacle is not less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to decelerate to a stop.

[0014] Furthermore, when detecting obstacles and determining the obstacle avoidance zone to which they belong based on the obstacle's location information, the process also includes:

[0015] S510. Determine whether the detected obstacle belongs to the emergency obstacle avoidance zone;

[0016] S511. If so, determine that the obstacle belongs to the emergency obstacle avoidance zone and control the vehicle to execute the emergency obstacle avoidance strategy.

[0017] S512. If the obstacle does not belong to the emergency obstacle avoidance zone, proceed to S520.

[0018] S520. Determine whether the obstacle is a valid obstacle;

[0019] S521. If it is a valid obstacle, then determine the obstacle avoidance zone to which the obstacle belongs;

[0020] S522. If it is not a valid obstacle, re-detect.

[0021] Furthermore, the operating mode includes at least one of a straight-line mode, a turning mode, and a stationary rotation mode;

[0022] In straight-ahead mode, the obstacle avoidance zone is defined as a parallelogram and is symmetrically distributed about the vehicle's centerline.

[0023] In turning mode, the obstacle avoidance zone is defined as an asymmetrical shape along the vehicle's centerline, and the obstacle avoidance width distance along the vehicle's width direction in the inner turning direction is greater than the obstacle avoidance width distance in the outer turning direction.

[0024] In the stationary rotation mode, the obstacle avoidance area is circular, with the center point of the vehicle as the center.

[0025] Furthermore, operating parameters are extracted, including one or more of operating speed and turning radius;

[0026] In straight-ahead mode, the obstacle avoidance zone is defined according to the operating speed. The higher the vehicle's operating speed, the larger the area of ​​the obstacle avoidance zone.

[0027] In turning mode, the obstacle avoidance zone is defined based on the operating speed and turning radius. The greater the vehicle operating speed and / or the greater the turning radius, the greater the obstacle avoidance width distance of the obstacle avoidance zone along the vehicle width direction.

[0028] Furthermore, when defining the obstacle avoidance zone, the operating parameters and the corresponding rated dimensions of each obstacle avoidance zone are set, a table of domain variation coefficients corresponding to each operating parameter is established, the current operating parameters are obtained, the domain variation coefficients corresponding to the current operating parameters are obtained, and the original rated dimensions of each obstacle avoidance zone are multiplied by the domain variation coefficients to obtain the dimensions of each obstacle avoidance zone at the current time.

[0029] Furthermore, it also includes the following steps:

[0030] The vehicle's automatic driving route is obtained, and the target driving area is obtained by combining the vehicle's shape characteristics and detection width.

[0031] Based on the location and shape of the detected obstacle, determine whether there is a blind spot where the area behind the obstacle overlaps with the target driving area;

[0032] If a blind spot exists, determine the obstacle avoidance zone where the blind spot is located, include the blind spot in the hierarchical object, and execute the obstacle avoidance strategy of the corresponding obstacle avoidance zone according to the highest priority detected.

[0033] If no blind spot exists, maintain the current obstacle avoidance strategy.

[0034] Furthermore, after detecting an obstacle, it is determined whether the obstacle is a dynamic obstacle or a static obstacle;

[0035] Calculate the speed and size of the obstacle, and determine whether the obstacle has a tendency to move towards the vehicle.

[0036] If so, determine that the obstacle is a dynamic obstacle and increase the priority of the obstacle accordingly;

[0037] If not, determine that the obstacle is a static obstacle and maintain the current obstacle avoidance strategy;

[0038] If the obstacle is static, maintain the current obstacle avoidance strategy.

[0039] Secondly, the present invention provides an obstacle avoidance terminal applied to the obstacle avoidance control method for unmanned vehicles as described above, comprising:

[0040] The obstacle avoidance strategy formulation unit is used to determine the vehicle operation mode, extract operation parameters, define each obstacle avoidance zone according to the operation parameters, and formulate obstacle avoidance strategies corresponding to each obstacle avoidance zone.

[0041] The detection unit is used to detect obstacles and send the location information of the obstacles to the analysis and processing unit;

[0042] The analysis and processing unit is used to receive the location information of the obstacles, determine the obstacle avoidance zone to which each obstacle belongs, classify the obstacles according to their respective obstacle avoidance zones, and determine the highest priority of the detected obstacles.

[0043] The execution unit is used to execute the obstacle avoidance strategy for the corresponding obstacle avoidance zone according to the highest priority among the obstacles.

[0044] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0045] The vehicle's operating status is defined one-to-one with the obstacle avoidance zone, and the obstacle avoidance strategy corresponding to the obstacle avoidance zone is formulated in advance. According to the obstacle avoidance zone, the obstacle is classified. Only the highest priority among the obstacles needs to be determined to determine the corresponding obstacle avoidance strategy. The hierarchical management and control is more adaptable to application scenarios with many obstacles, and the processing speed is faster and the efficiency is higher.

[0046] When the vehicle turns, in order to better detect and avoid obstacles on the inside of the turn, the obstacle avoidance area is widened by increasing the obstacle avoidance width distance along the width direction of the vehicle in the turning direction in turning mode. This extends the detection range and makes obstacle avoidance more effective and timely. Attached Figure Description

[0047] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating an obstacle avoidance control method for unmanned vehicles provided by the present invention.

[0049] Figure 2 This is a schematic diagram of the overall process of one implementation of the obstacle avoidance control method for unmanned vehicles provided by the present invention.

[0050] Figure 3 This is a flowchart illustrating the obstacle effectiveness judgment process in an obstacle avoidance control method for unmanned vehicles provided by the present invention.

[0051] Figure 4 This is a schematic diagram of each obstacle avoidance zone in the straight-ahead mode of an unmanned vehicle obstacle avoidance control method provided by the present invention, under one implementation method.

[0052] Figure 5 This is a schematic diagram of another implementation of the obstacle avoidance zone in the straight-ahead mode of the obstacle avoidance control method for unmanned vehicles provided by the present invention.

[0053] Figure 6 This is a schematic diagram of each obstacle avoidance zone in a turning mode under one implementation method of an unmanned vehicle obstacle avoidance control method provided by the present invention.

[0054] Figure 7 This is a schematic diagram of a blind spot in one embodiment of an obstacle avoidance control method for unmanned vehicles provided by the present invention. Detailed Implementation

[0055] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] Reference Figure 1 , Figure 4 , Figure 5 and Figure 6 In a first aspect, the present invention provides an obstacle avoidance control method for unmanned vehicles, used for the automatic driving of unmanned vehicles, comprising the following steps:

[0058] Predefine obstacle avoidance zones and strategies: Determine the vehicle's operating mode, extract operating parameters, define each obstacle avoidance zone based on the operating parameters, and formulate obstacle avoidance strategies corresponding to each obstacle avoidance zone. In this step, the vehicle's operating state is first determined. Since the vehicle's operating state changes frequently, such as whether the vehicle is in a straight, turning, or rotating mode, or the vehicle's operating speed, turning angle, vehicle load weight, road curvature changes, etc., each different operating parameter affects its operating state. Therefore, the obstacle avoidance zone changes according to the real-time changes in the vehicle's operating parameters and is a dynamically changing area. Furthermore, obstacle avoidance strategies corresponding to the obstacle avoidance zones are pre-defined.

[0059] Obstacles are detected, and their corresponding obstacle avoidance zones are determined based on their location information. Obstacles are then classified according to their respective obstacle avoidance zones, with higher priority zones closer to the vehicle. Since each obstacle avoidance zone covers a different area and is defined along the vehicle's direction of travel, extending outwards in layers, various obstacles exist within the vehicle's driving area. The location information of each obstacle is determined by calculating its distance from the vehicle's foreground. This location information is then used to determine the corresponding obstacle avoidance zone each obstacle falls into. If an obstacle spans multiple obstacle avoidance zones, it is defined as the one closest to the vehicle. This process associates all obstacles with one obstacle avoidance zone, and the obstacles are classified using the defined zones. Since the number of obstacles is variable—the number and distance of obstacles faced by the vehicle vary depending on the scenario or time—while the number of obstacle avoidance zones can be manually defined, the number of classification levels is fixed. To reduce computational burden and speed up processing, variable obstacles are uniformly categorized into defined levels and processed according to their classification type.

[0060] The system identifies the highest priority obstacle detected and executes the obstacle avoidance strategy for the corresponding obstacle avoidance zone. Since the higher the priority of an obstacle, the closer it is to the vehicle, the more likely it is to pose a safety hazard to the normal operation of the vehicle. Therefore, by identifying the highest priority among all obstacles, the required obstacle avoidance strategy can be determined. By using hierarchical management and control, the system can meet the needs of complex and ever-changing application scenarios, adapt well to and solve situations with multiple obstacles, and process faster and more efficiently.

[0061] More specifically, the obstacle avoidance zone includes, from the inside out, an emergency obstacle avoidance zone, an inner obstacle avoidance zone, an outer obstacle avoidance zone, and a safety zone. The area of ​​the areas included in the emergency obstacle avoidance zone, the inner obstacle avoidance zone, the outer obstacle avoidance zone, and the safety zone gradually increases. The emergency obstacle avoidance zone corresponds to the first priority, the inner obstacle avoidance zone corresponds to the second priority, the outer obstacle avoidance zone corresponds to the third priority, and the safety zone corresponds to the fourth priority. The priority order of the first priority, the second priority, the third priority, and the fourth priority decreases in that order, with the emergency obstacle avoidance zone having the highest priority and the safety zone having the lowest priority.

[0062] The area of ​​each obstacle avoidance zone changes with the vehicle's operating parameters. The area of ​​each obstacle avoidance zone can be dynamically changed based on factors such as the vehicle's operating speed, turning angle, and load weight. Furthermore, each obstacle avoidance zone includes a front obstacle avoidance zone in front of the vehicle and side obstacle avoidance zones on both sides of the vehicle. Taking the emergency obstacle avoidance zone as an example, it includes a front emergency obstacle avoidance zone and two side emergency obstacle avoidance zones. When the area of ​​the obstacle avoidance zone changes dynamically, the front emergency obstacle avoidance zone and the side emergency obstacle avoidance zones can change according to the same change factor, or they can change according to the front change factor and the side change factor respectively. That is, the front emergency obstacle avoidance zone and the side emergency obstacle avoidance zones can be consistent or separate when they change dynamically.

[0063] Combination Figure 5 In one implementation, the front obstacle avoidance zone and the side obstacle avoidance zone can be independent graphic areas. For example, the front obstacle avoidance zone can be an independent rectangular area, and the side obstacle avoidance zone can be another independent rectangular area. In another implementation, the front obstacle avoidance zone and the side obstacle avoidance zone can be different parts of the same graphic area. For example, this graphic area is a circle, and the front obstacle avoidance zone and the two side obstacle avoidance zones each occupy one-third of it. The front obstacle avoidance zone is one-third of the circle in the direction directly in front of the vehicle, and the side obstacle avoidance zones are one-third of the circles on the left and right sides.

[0064] In this embodiment, the obstacle avoidance strategy corresponding to the emergency obstacle avoidance zone is as follows:

[0065] Determine the vehicle's current speed and / or distance from obstacles;

[0066] When the vehicle's current operating speed is greater than the emergency obstacle avoidance speed setting value, and / or the distance between the vehicle and the obstacle is less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to apply the emergency brake.

[0067] When the vehicle's current operating speed is not greater than the emergency obstacle avoidance speed setting value, and the distance between the vehicle and the obstacle is not less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to decelerate to a stop.

[0068] The obstacle avoidance strategy for the inner obstacle avoidance zone is to control the vehicle to decelerate to the first preset obstacle avoidance speed.

[0069] The obstacle avoidance strategy for the outer obstacle avoidance zone is to control the vehicle to decelerate to the second preset obstacle avoidance speed.

[0070] The obstacle avoidance strategy in the safe zone is to control the vehicle to maintain its current speed.

[0071] The area range of the obstacle avoidance zone is determined by formula V. t 2 -V0 2=2as, where V is the running speed, a is the braking acceleration, and s is the preset value for the size of the obstacle avoidance zone. Since each obstacle avoidance zone has a corresponding braking acceleration and a preset obstacle avoidance speed, the length and size of each obstacle avoidance zone can be obtained. Moreover, by controlling the transition between two obstacle avoidance zones, the vehicle decelerates according to the braking acceleration of the previous obstacle avoidance zone to reach the next obstacle avoidance zone, which just meets the requirements of the next obstacle avoidance zone. This facilitates smooth speed changes, avoids emergency braking, avoids sudden speed changes, and prevents damage to the vehicle body due to excessive inertia. For example, if the vehicle speed is 1.5 m / s and an obstacle is detected in the outer obstacle avoidance zone, the vehicle is first controlled to decelerate using the second braking acceleration. After passing the distance between the outer and inner obstacle avoidance zones, when the obstacle enters the inner obstacle avoidance zone, the speed has already decreased to 1.1 m / s. 1.1 m / s is the second preset obstacle avoidance speed. Then, the vehicle is controlled to decelerate using the first braking acceleration. After passing the distance between the inner and emergency obstacle avoidance zones, when the obstacle enters the emergency obstacle avoidance zone, the speed has already decreased to 0.5 m / s. 0.5 m / s is the first preset obstacle avoidance speed, which is exactly the speed at which the vehicle decelerates to the corresponding preset obstacle avoidance speed after passing the obstacle avoidance distance set for each zone.

[0072] When an obstacle appears in the emergency avoidance zone, to avoid threatening the vehicle's normal operation, it is necessary to significantly reduce the vehicle's speed. However, there are two scenarios for significantly reducing the vehicle's speed: if the vehicle's current speed is greater than the emergency avoidance speed setting, and / or the distance between the vehicle and the obstacle is less than the emergency avoidance distance setting, it indicates that the vehicle is in great danger and is very likely to collide with the obstacle, requiring immediate emergency braking; however, if the vehicle's current speed is not greater than the emergency avoidance speed setting, and the distance between the vehicle and the obstacle is not less than the emergency avoidance distance setting, then it is sufficient to control the vehicle to decelerate normally to a stop.

[0073] In addition, the emergency obstacle avoidance zone is equipped with emergency obstacle avoidance speed settings and emergency obstacle avoidance distances to prevent the vehicle from locking up due to emergency braking as soon as an obstacle is detected in the emergency obstacle avoidance zone, thus reducing damage to the vehicle, especially the wheels of heavy-duty vehicles.

[0074] Compared to the significant speed reduction in the emergency obstacle avoidance zone, the obstacle avoidance strategy in the inner obstacle avoidance zone is a rapid deceleration process, while the strategy in the outer obstacle avoidance zone is a slow deceleration process. Of course, for scenarios with low operating speeds, the inner and outer obstacle avoidance zones can also be combined into one area.

[0075] Reference Figure 2 As one implementation method, when detecting obstacles and determining the obstacle avoidance zone to which they belong based on the location information of the obstacles, the method further includes:

[0076] S510. Determine whether the detected obstacle belongs to the emergency obstacle avoidance zone;

[0077] S511. If so, determine that the obstacle belongs to the emergency obstacle avoidance zone and control the vehicle to execute the emergency obstacle avoidance strategy.

[0078] S512. If the obstacle does not belong to the emergency obstacle avoidance zone, proceed to S520.

[0079] S520. Determine whether the obstacle is a valid obstacle;

[0080] S521. If it is a valid obstacle, then determine the obstacle avoidance zone to which the obstacle belongs;

[0081] S522. If it is not a valid obstacle, re-detect.

[0082] It should be noted that when the obstacle is located outside the emergency avoidance zone, it is necessary to reassess its validity to avoid false detections or fast-moving objects. To improve detection accuracy, a validity assessment is required. (Refer to...) Figure 3 Specifically, this includes: when an obstacle is detected, a timer is started; if the detection signal continues for a preset time, meaning the obstacle remains, the obstacle is considered valid, the timer is reset, and the obstacle's obstacle avoidance zone is determined; if the detection signal is interrupted and disappears within the preset time, it proves that the obstacle has left the corresponding area, and it is considered an invalid obstacle, and the detection is repeated.

[0083] Combination Figure 3 , Figure 4 and Figure 5 In this embodiment, the operating mode includes at least one of straight-line mode, turning mode, and stationary rotation mode;

[0084] In straight-ahead mode, the obstacle avoidance zone is defined as a parallelogram and is symmetrically distributed about the vehicle's centerline.

[0085] More specifically, for example, the operating speed of an autonomous vehicle indoors is generally between 2.0 m / s and 2.3 m / s, with a vehicle width of about 1 m. Multiple sensors are installed at the front of the vehicle. For the front of the vehicle, all obstacle avoidance zones share the frontmost edge as their common side. The emergency obstacle avoidance zone is generally 0.8 m long and 1.38 m wide; the inner obstacle avoidance zone is 1.6 m long and 1.74 m wide; and the outer obstacle avoidance zone is 2.3 m long and 2.48 m wide. In addition, a safety zone can be set within the obstacle avoidance area. The safety front zone is 4.1 m long and 2.98 m wide. Furthermore, the emergency obstacle avoidance zone, the inner obstacle avoidance zone, and the outer obstacle avoidance zone... The centerlines of the forward obstacle avoidance zone and the safe forward zone coincide with the centerline of the vehicle, and are symmetrically distributed left and right using this as the axis of symmetry. Sensors are installed on the sides of the vehicle. For the sides of the vehicle, the left and right side obstacle avoidance zones are symmetrically distributed with the vehicle's centerline as the axis of symmetry. After merging the left and right sides, the length of the emergency side obstacle avoidance zone is 2.0m and the width is 1.6m; the length of the inner forward obstacle avoidance zone is 2.0m and the width is 1.96m; the length of the outer forward obstacle avoidance zone is 2.0m and the width is 2.7m; and the length of the safe forward zone is 2.0m and the width is 3.2m. The length direction refers to the length direction of the vehicle, and the width direction refers to the width direction of the vehicle. Of course, the above is only one embodiment of the present invention and should not be construed as limiting the present invention.

[0086] In turning mode, the obstacle avoidance zone is defined as an asymmetrical shape along the vehicle's centerline, with the obstacle avoidance width distance along the vehicle's width direction on the inside of the turn being greater than that on the outside of the turn. Compared to the rectangular shape of the obstacle avoidance zone in straight-line mode, which is symmetrically distributed, in turning mode, to better accommodate obstacles that may exist in the inner wheel difference area or blind spot area of ​​the turn, and to better reflect the area where the obstacle should belong, thus achieving better detection and avoidance, the obstacle avoidance zone will deform in accordance with the turning direction. Specifically, if the vehicle turns right, the front end of the obstacle avoidance zone also bends to the right, and the obstacle avoidance zone also makes a corresponding displacement in the vehicle's width direction, moving towards the inside of the turn. This results in the obstacle avoidance zone having a greater obstacle avoidance width distance along the vehicle's width direction on the inside of the turn than on the outside of the turn, thus better detecting obstacles on the inside of the turn.

[0087] In the stationary rotation mode, the obstacle avoidance area is circular, with the center point of the vehicle as the center. When the unmanned vehicle rotates in place, in order to prevent the fork arm of the unmanned vehicle from hitting obstacles when sweeping, the obstacle avoidance area uses the center point of the vehicle as the center of rotation. It should be noted that if the center of rotation of the vehicle is not its center point, the center of rotation can also be used as the center of the obstacle avoidance area.

[0088] In this embodiment, when defining the obstacle avoidance zone, operating parameters are extracted, and the operating parameters include at least one or more of the operating speed and turning radius;

[0089] In straight-ahead mode, the obstacle avoidance zone is defined according to the operating speed. The higher the vehicle's operating speed, the larger the area of ​​the obstacle avoidance zone. The front obstacle avoidance zone in front of the vehicle and the side obstacle avoidance zones on both sides of the vehicle will change with the vehicle's operating speed.

[0090] In turning mode, an obstacle avoidance zone is defined based on the operating speed and turning radius. This obstacle avoidance zone is fan-shaped, with the curvature of its inner and outer arc sides equal to the turning radius. The greater the vehicle speed and / or the greater the turning radius, the larger the obstacle avoidance width along the vehicle's width direction. It's important to note that different operating speeds and turning radii correspond to different fan-shaped obstacle avoidance zones. Alternatively, it can be divided by speed ranges; for example, 0–1 m / s is one range, and 1–2 m / s is another. Within the same speed range, the obstacle avoidance zone has the same length, which is the length of the middle arc of the fan-shaped ring, i.e., the average length of the inner and outer arc sides. Of course, the fan-shaped obstacle avoidance zone is also affected by factors such as vehicle load and road curvature. When the vehicle load is greater, the area of ​​the fan-shaped obstacle avoidance zone needs to be increased to ensure stable operation and prevent sudden braking. Similarly, when the vehicle is traveling uphill or downhill, the size of the obstacle avoidance zone needs to be adjusted accordingly to ensure that the vehicle can fully consider factors such as current speed, turning radius, load, and road conditions. When the autonomous vehicle's turning radius is greater, the inner wheel difference is greater, and the radius of the arc edges on both sides of the fan-shaped zone is also greater. The emergency obstacle avoidance zone, inner obstacle avoidance zone, outer obstacle avoidance zone, and safety zone, which match the current autonomous vehicle status, expand layer by layer. For example, in turning mode, if the autonomous vehicle's speed is 1.5 m / s, the emergency obstacle avoidance zone can be set to 1 m in length and 1.5 m in width, the inner obstacle avoidance zone to 1.2 m in length and 1.8 m in width, and the outer obstacle avoidance zone to 1.5 m in length and 2 m in width.

[0091] As one implementation method, when defining the obstacle avoidance zone, the operating parameters and the corresponding rated dimensions of each obstacle avoidance zone are set. These rated dimensions can be, but are not limited to, the rated length, rated width, rated arc, rated radius, etc. of the obstacle avoidance zone, depending on different operating modes. Moreover, the operating parameters can also be the operating speed, turning arc, etc. A domain variation coefficient lookup table corresponding to the operating parameters is established, wherein the domain variation coefficient can be one or more of the domain width coefficient, domain length coefficient, or domain arc coefficient.

[0092] After obtaining the current operating parameters, the domain variation coefficients corresponding to the current operating parameters are obtained. The original rated size of each obstacle avoidance zone is multiplied by the domain variation coefficient to obtain the size of each obstacle avoidance zone at the current time.

[0093] Taking the dimensions of each obstacle avoidance zone in straight-line mode as an example, at the rated speed V1, the length of the emergency obstacle avoidance zone is L1 and the width is W1, the length of the outer obstacle avoidance zone is L2 and the width is W2, and the length of the inner obstacle avoidance zone is L3 and the width is W3. When the speed changes to V2, the domain length coefficient is A1 and the domain width coefficient is B1. At this moment, the length of the emergency obstacle avoidance zone is A1*L1 and the width is B1*W1, the length of the outer obstacle avoidance zone is A1*L2 and the width is B1*W2, and the length of the inner obstacle avoidance zone is A1*L3 and the width is B1*W3. The values ​​of A1 and B1 can be equal or unequal. The domain width coefficient and the domain length coefficient can have only one of them or both of them.

[0094] It should be noted that, in order to improve the smoothness of speed changes and avoid sudden changes in vehicle speed, the area of ​​each obstacle avoidance zone is increased as the vehicle speed increases. This aims to increase the deceleration distance and deceleration time, reduce the absolute value of acceleration, and minimize sudden speed drops. Furthermore, the design of the variable coefficients for each domain can be based on V... t 2 -V0 2 =2as, meaning that when the vehicle speed is high, the outer obstacle avoidance zone is enlarged to increase the detection range. When an obstacle enters the outer obstacle avoidance zone, it first decelerates with a small braking acceleration. Simultaneously, as the vehicle speed decreases, the size of each obstacle avoidance zone also decreases, effectively increasing the distance between the original outer and inner obstacle avoidance zones. After a longer deceleration distance, the vehicle enters the inner obstacle avoidance zone just as its speed drops to the second preset obstacle avoidance speed. After decelerating in the inner zone, the vehicle enters the emergency obstacle avoidance zone just as its speed drops to the first preset obstacle avoidance speed. At this point, the first preset obstacle avoidance speed does not exceed the emergency obstacle avoidance speed setting, allowing the vehicle to decelerate to a stop normally, avoiding emergency braking. The above description of the obstacle avoidance zone data is merely illustrative and does not constitute a limitation. Those skilled in the art can adjust the size and shape of the obstacle avoidance zone according to the actual vehicle size, type, speed, curvature, etc.

[0095] Reference Figure 7 As one implementation method, the unmanned vehicle obstacle avoidance control method described in this embodiment obtains the vehicle's automatic driving route before automatic driving, and obtains the target driving area by combining the vehicle's shape characteristics and detection width.

[0096] When an autonomous vehicle detects a large obstacle during its operation, a blind spot may occur. In this case, besides classifying the obstacle, the vehicle's movement needs to be controlled in real-time based on the blind spot situation. Therefore, in this embodiment, the position and shape of the detected obstacle are used to determine if there is a blind spot where the area behind the obstacle overlaps with the target driving area. More specifically, the left and right edge points of the obstacle are obtained. Using the vehicle's detection unit as the endpoint, two rays are drawn through these two points. The left and right edge points are the outermost points on both sides of the obstacle when the detection unit is the endpoint. The area enclosed by the two rays includes the obstacle, dividing the area into a front area and a back area. The front area is between the vehicle and the obstacle, and the back area is behind the obstacle. The area where the area enclosed by the two rays overlaps with the target driving area behind the obstacle is defined as the blind spot. Figure 7 As shown, the vehicle is about to enter the turning area. At the current position, an obstacle can be detected in front. In the blind spot of the obstacle in front, there is another obstacle, which is at the turning position. Due to the influence of the obstacle in front, the vehicle cannot detect the obstacle behind. If the vehicle turns normally, it is very likely to hit the obstacle behind just as it exits the turn. Therefore, it is necessary to detect and judge this blind spot.

[0097] If a blind spot exists, it means that the area blocked by the obstacle overlaps with the target driving area. The obstacle avoidance zone where the blind spot is located is determined, the blind spot is included in the hierarchical object, and the obstacle avoidance strategy of the corresponding obstacle avoidance zone is executed according to the highest priority detected.

[0098] If no blind spot exists, maintain the current obstacle avoidance strategy.

[0099] Of course, it is possible to set the obstacle avoidance strategy to only be adjusted when there is a blind spot within a certain obstacle avoidance zone. For example, the obstacle avoidance strategy will only be adjusted if there is a blind spot in the inner obstacle avoidance zone, while it can be ignored if there is a blind spot in the outer obstacle avoidance zone.

[0100] As one implementation method, after detecting an obstacle, it is also necessary to determine whether the obstacle is a dynamic obstacle or a static obstacle;

[0101] Calculate the speed and size of the obstacle, and determine whether the obstacle has a tendency to move towards the vehicle.

[0102] If the obstacle's movement speed is towards the vehicle or towards the vehicle's target driving area, and it is calculated that it has a tendency to move closer to the vehicle, the obstacle is determined to be a dynamic obstacle, and the priority of the obstacle is increased.

[0103] If there is no tendency for the obstacle to move towards the vehicle, it is determined to be a static obstacle, and the current obstacle avoidance strategy is maintained. It should be noted that if an obstacle has a speed, but its speed direction is not towards the vehicle, it is also treated as a static obstacle.

[0104] The above methods can better identify dynamic obstacles that are moving toward the vehicle or toward the position where the vehicle will appear in the target driving area. By increasing the priority of the corresponding obstacles, the vehicle can take more appropriate obstacle avoidance strategies and slow down to avoid obstacles in advance.

[0105] Secondly, the present invention provides an obstacle avoidance terminal applied to the obstacle avoidance control method for unmanned vehicles as described above, comprising:

[0106] The obstacle avoidance strategy formulation unit is used to determine the vehicle operation mode, extract operation parameters, define each obstacle avoidance zone according to the operation parameters, and formulate obstacle avoidance strategies corresponding to each obstacle avoidance zone.

[0107] The detection unit is used to detect obstacles and send the location information of the obstacles to the analysis and processing unit;

[0108] The analysis and processing unit is used to receive the location information of the obstacles, determine the obstacle avoidance zone to which each obstacle belongs, classify the obstacles according to their respective obstacle avoidance zones, and determine the highest priority of the detected obstacles.

[0109] The execution unit is used to execute the obstacle avoidance strategy for the corresponding obstacle avoidance zone according to the highest priority among the obstacles.

[0110] It should be noted that the obstacle avoidance strategy formulation unit has pre-set obstacle avoidance zones and corresponding obstacle avoidance strategies associated with each operating state. During actual operation, once the vehicle operating mode is determined, the relevant operating parameters can be extracted to immediately correspond to the appropriate obstacle avoidance zone and strategy. The detection unit is responsible for detecting external obstacles in real time. The analysis and processing unit determines the classification type of each obstacle based on its location information, identifies the highest priority, and sends the corresponding instruction to the execution unit. The execution unit then executes the obstacle avoidance strategy corresponding to the highest priority obstacle avoidance zone to achieve obstacle avoidance.

[0111] Compared with existing technologies, this invention provides an obstacle avoidance control method and terminal for unmanned vehicles, which defines the vehicle's operating status and obstacle avoidance zones in a one-to-one correspondence, and pre-defines the obstacle avoidance strategy corresponding to the obstacle avoidance zone; based on the obstacle avoidance zone, obstacles are classified, and only the highest priority among the obstacles needs to be determined to determine the corresponding obstacle avoidance strategy. The hierarchical management and control is more adaptable to application scenarios with many obstacles, and the processing speed is faster and the efficiency is higher.

[0112] When the vehicle turns, in order to better detect and avoid obstacles on the inside of the turn, the obstacle avoidance area is widened by increasing the obstacle avoidance width distance along the width direction of the vehicle in the turning direction in turning mode. This extends the detection range and makes obstacle avoidance more effective and timely.

[0113] Finally, it should be emphasized that the present invention is not limited to the above-described embodiments. The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0114] The above description outlines the main process steps of the invention. Other functional steps may be interspersed within this process, and the logical order and process steps may be disrupted. If the data processing method follows this process step format or the core idea of ​​the data processing is similar or identical, it should be protected.

Claims

1. An obstacle avoidance control method for unmanned vehicles, used for the automatic driving of unmanned vehicles, characterized in that, Includes the following steps: The system detects obstacles, determines their corresponding obstacle avoidance zones based on their location information, and classifies obstacles according to their respective obstacle avoidance zones, with higher priority given to obstacle avoidance zones that are closer to the vehicle. Determine the highest priority detected obstacle and execute the obstacle avoidance strategy for the corresponding obstacle avoidance zone; The obstacle avoidance zone is configured to first determine the vehicle's operating mode, extract operating parameters, and define the obstacle avoidance strategy according to the operating parameters; the obstacle avoidance strategy is configured to be formulated according to different obstacle avoidance zones. The operating mode includes at least one of the following: straight-line mode, turning mode, and stationary rotation mode; In straight-ahead mode, the obstacle avoidance zone is defined as a parallelogram and is symmetrically distributed about the vehicle's centerline. In turning mode, the obstacle avoidance zone is defined as an asymmetrical shape along the vehicle's centerline, and the obstacle avoidance width distance along the vehicle's width direction in the inner turning direction is greater than the obstacle avoidance width distance in the outer turning direction. In the stationary rotation mode, the obstacle avoidance area is circular, with the center point of the vehicle as the center.

2. The obstacle avoidance control method for unmanned vehicles according to claim 1, characterized in that, The obstacle avoidance zone includes, from the inside out, an emergency obstacle avoidance zone, an inner obstacle avoidance zone, and an outer obstacle avoidance zone. The area of ​​the area included in the emergency obstacle avoidance zone, the inner obstacle avoidance zone, and the outer obstacle avoidance zone gradually increases. The area of ​​the obstacle avoidance zone changes with the operating parameters of the vehicle. Each obstacle avoidance zone includes a front obstacle avoidance zone in front of the vehicle and side obstacle avoidance zones on both sides of the vehicle.

3. The obstacle avoidance control method for unmanned vehicles according to claim 2, characterized in that, The obstacle avoidance strategy corresponding to the emergency obstacle avoidance zone is as follows: Determine the vehicle's current speed and / or distance from obstacles; When the vehicle's current operating speed is greater than the emergency obstacle avoidance speed setting value, and / or the distance between the vehicle and the obstacle is less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to apply the emergency brake. When the vehicle's current operating speed is not greater than the emergency obstacle avoidance speed setting value, and the distance between the vehicle and the obstacle is not less than the emergency obstacle avoidance distance setting value, the vehicle is controlled to decelerate to a stop.

4. The obstacle avoidance control method for unmanned vehicles according to claim 2, characterized in that, When detecting obstacles and determining the obstacle avoidance zone to which they belong based on the obstacle's location information, the method further includes: S510. Determine whether the detected obstacle belongs to the emergency obstacle avoidance zone; S511. If so, determine that the obstacle belongs to the emergency obstacle avoidance zone and control the vehicle to execute the emergency obstacle avoidance strategy. S512. If the obstacle does not belong to the emergency obstacle avoidance zone, proceed to S520. S520. Determine whether the obstacle is a valid obstacle; S521. If it is a valid obstacle, then determine the obstacle avoidance zone to which the obstacle belongs; S522. If it is not a valid obstacle, re-detect.

5. The obstacle avoidance control method for unmanned vehicles according to claim 4, characterized in that, Extract operating parameters, which include one or more of operating speed and turning radius; In straight-line mode, the obstacle avoidance zone is defined according to the operating speed. The higher the vehicle's operating speed, the larger the area of ​​the obstacle avoidance zone. In turning mode, the obstacle avoidance zone is defined based on the operating speed and turning radius. The greater the vehicle operating speed and / or the greater the turning radius, the greater the obstacle avoidance width distance of the obstacle avoidance zone along the vehicle width direction.

6. The obstacle avoidance control method for an unmanned vehicle according to claim 4, characterized in that, When defining the obstacle avoidance zone, set the operating parameters and the corresponding rated dimensions of each obstacle avoidance zone, establish a reference table of domain variation coefficients corresponding to each operating parameter, obtain the current operating parameters, compare and obtain the domain variation coefficients corresponding to the current operating parameters, multiply the original rated dimensions of each obstacle avoidance zone by the domain variation coefficients, and obtain the dimensions of each obstacle avoidance zone at the current time.

7. The obstacle avoidance control method for unmanned vehicles according to claim 4, characterized in that, It also includes the following steps: The vehicle's automatic driving route is obtained, and the target driving area is obtained by combining the vehicle's shape characteristics and detection width. Based on the location and shape of the detected obstacle, determine whether there is a blind spot where the area behind the obstacle overlaps with the target driving area; If a blind spot exists, determine the obstacle avoidance zone where the blind spot is located, include the blind spot in the hierarchical object, and execute the obstacle avoidance strategy of the corresponding obstacle avoidance zone according to the highest priority detected. If no blind spot exists, maintain the current obstacle avoidance strategy.

8. The obstacle avoidance control method for unmanned vehicles according to claim 7, characterized in that, After detecting an obstacle, determine whether the obstacle is dynamic or static; Calculate the speed and size of the obstacle, and determine whether the obstacle has a tendency to move towards the vehicle. If so, determine that the obstacle is a dynamic obstacle and increase the priority of the obstacle accordingly; If none is found, the obstacle is determined to be a static obstacle, and the current obstacle avoidance strategy is maintained.

9. An obstacle avoidance terminal applied to the obstacle avoidance control method for unmanned vehicles as described in any one of claims 1 to 8, characterized in that, include: The obstacle avoidance strategy formulation unit is used to determine the vehicle operation mode, extract operation parameters, define each obstacle avoidance zone according to the operation parameters, and formulate obstacle avoidance strategies corresponding to each obstacle avoidance zone. The detection unit is used to detect obstacles and send the location information of the obstacles to the analysis and processing unit; The analysis and processing unit is used to receive the location information of the obstacles, determine the obstacle avoidance zone to which each obstacle belongs, classify the obstacles according to their respective obstacle avoidance zones, and determine the highest priority of the detected obstacles. The execution unit is used to execute the obstacle avoidance strategy for the corresponding obstacle avoidance zone according to the highest priority among the obstacles.

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