AGV obstacle avoidance method and system based on navigation radar scanning

Abstract

The invention discloses an AGV obstacle avoidance method and system based on navigation radar scanning, and the method comprises the steps: an obstacle avoidance step: obtaining the polar coordinates of a current scanning point, and converting the polar coordinates into the coordinates of a rectangular coordinate system; judging whether the coordinate of the rectangular coordinate system is located in one of the four safety areas, and if so, adding 1 to the number of obstacles in the corresponding safety area; after the scanning cycle is completed, calculating the proportion of the number of obstacles in each safety area, judging each proportion based on the driving direction of the vehicle, and if the proportion exceeds a preset proportion, giving an alarm prompt; the four safety areas comprise a front area, a left area, a rear area and a right area. According to the invention, obstacles can be detected from the front, back, left and right directions, the recognition accuracy is improved, the safe area range is adjusted according to the driving mode, the driving direction and the driving speed, and the safe parking distance is increased to better avoid collision.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle safety, and particularly to an AGV obstacle avoidance method and system for navigation radar scanning. Background Art

[0002] An AGV (Automated Guided Vehicle) is an industrial vehicle that loads goods automatically or manually, travels automatically along a set route or tow a load-carrying trolley to a designated location, and then loads and unloads goods automatically or manually. Currently, it is widely used in the automated handling systems in industries, military, tobacco, and intelligent parking garages. In recent years, AGVs have also gradually developed towards the direction of intelligence, hoping that AGVs can still work normally after reducing or leaving human intervention. Since the working scenarios of AGVs are relatively complex, people expect AGVs to have the function of obstacle detection to reduce the possibility of collision between AGVs and obstacles such as height limit beams, rolling shutter doors, and other vehicles. The existing methods for detecting obstacles by radar often only consider one direction, such as only detecting the forward or backward direction, and do not comprehensively consider the obstacles in the four directions of front, rear, left, and right to judge the possibility of collision, resulting in a reduction in the accuracy of obstacle recognition; in addition, the detection area cannot be automatically adjusted according to the driving direction and speed of the AGV, resulting in untimely processing and collision accidents. Summary of the Invention

[0003] The main object of the present invention is to overcome the above-mentioned defects in the prior art, and propose an AGV obstacle avoidance method and system for navigation radar scanning, which can detect obstacles in the four directions of front, rear, left, and right, improve the recognition accuracy, and at the same time adjust the safety area range according to the driving mode, driving direction, and driving speed, and increase the safe stopping distance to better avoid collisions.

[0004] The present invention adopts the following technical solutions:

[0005] On the one hand, an AGV obstacle avoidance method for navigation radar scanning includes:

[0006] An obstacle avoidance step of obtaining the polar coordinates of the current scanning point, converting the polar coordinates into the coordinates of a rectangular coordinate system; judging whether the coordinates of the rectangular coordinate system are located in one of the four safety areas, and if so, increasing the number of obstacle points in the corresponding safety area by 1; after the completion of the current scanning cycle, calculating the proportion of the number of obstacle points in each safety area, and judging each proportion based on the driving direction of the vehicle. If the proportion exceeds a preset ratio, an alarm prompt is given; the four safety areas include the front area, the left area, the rear area, and the right area.

[0007] Preferably, before the obstacle avoidance step, it further includes:

[0008] Navigation radar mirror anomaly judgment steps, determine whether the navigation radar mirror is abnormal, if abnormal, give an alarm prompt; otherwise, enter the obstacle avoidance steps.

[0009] Preferably, the navigation radar mirror anomaly judgment steps specifically include:

[0010] Set the safety area of the navigation radar as a circle with a radius of L + L_corr, and divide this safety area into four regions: [0, 90°], (90°, 180°], (0, -90°], and (-90°, -180°); where L represents the fixed distance between the center point of the radar and the mirror; L_corr is the preset detection distance.

[0011] Obtain the polar coordinates (r, Theta) of the current scanning point, determine the safety area to which the scanning point belongs based on Theta, and when r is less than L + L_corr, increment the number of obstacle points in the corresponding safety area by 1; where r represents the distance from the scanning point to the center point, and Theta represents the angle of the scanning point.

[0012] After the radar scans a full circle, obtain the number of obstacle points in each safety area, and calculate the quotient of the number of obstacle points in each safety area and the total number of scanning points in the corresponding safety area to obtain the ratio.

[0013] If the ratio of one of the safety areas exceeds the first preset value or the total ratio of two or more safety areas exceeds the second preset value, and the duration exceeds the first preset time, then it is determined that the navigation radar mirror is abnormal.

[0014] Preferably, the AGV obstacle avoidance method based on navigation radar scanning further includes: a driving mode judgment step, obtain the driving mode of the vehicle, if it is the manual mode, then execute the obstacle avoidance steps, if it is the automatic mode, then execute the obstacle avoidance steps and perform driving speed control.

[0015] Preferably, in the obstacle avoidance steps, when the vehicle is moving forward, the width of the front area is greater than the width of the rear area; when the vehicle is moving backward, the width of the front area is less than the width of the rear area; when the vehicle is turning left, the length of the left area is greater than the right area; when the vehicle is turning right, the length of the right area is greater than the left area.

[0016] Preferably, if it is the automatic mode, the length and / or width of the front area, rear area, left area, and right area are automatically adjusted based on the vehicle driving speed and driving direction.

[0017] Preferably, in the obstacle avoidance step, the safe area is a matrix area; it is determined whether the coordinates in the rectangular coordinate system are located in one of the set four safe areas. If so, the number of obstacle points in the corresponding area is incremented by 1. Specifically, it includes:

[0018] If (-L 横向前 / 2) <= x <= (L 横向前 / 2) and 0 <= y <= L 纵向前 , it is determined that the coordinates in the rectangular coordinate system are located in the front area, and the number of obstacle points in the front area is incremented by 1; where x represents the abscissa value; y represents the ordinate value; L 横向前 represents the length of the front area; L 纵向前 represents the width of the front area;

[0019] If (-L 横向后 / 2) <= x <= (L 横向后 / 2) and -L 纵向后 <= y < 0, it is determined that the coordinates in the rectangular coordinate system are located in the rear area, and the number of obstacle points in the rear area is incremented by 1; where L 横向后 represents the length of the rear area; L 纵向后 represents the width of the rear area;

[0020] If (((-L 横向左 -L 横向前 ) / 2) <= x < (-L 横向前 / 2) and (-L 纵向左 / 2) <= y <= (L 纵向左 / 2), it is determined that the coordinates in the rectangular coordinate system are located in the left area, and the number of obstacle points in the left area is incremented by 1; where L 横向左 represents the length of the left area; L 纵向左 represents the width of the left area;

[0021] If (L 横向前 / 2) < x <= ((L 横向右 +L 横向前 ) / 2) and (-L 纵向右 / 2) <= y <= (L 纵向右 / 2), it is determined that the coordinates in the rectangular coordinate system are located in the right area, and the number of obstacle points in the right area is incremented by 1; where L 横向右 represents the length of the right area; L 纵向右 represents the width of the right area.

[0022] Preferably, in the obstacle avoidance step, the proportion of the number of obstacle points in each area is calculated. Specifically, it includes:

[0023] The total number of scan points in each safe area is calculated respectively as follows:

[0024] N1 = P1 * N; N2 = P2 * N; N3 = P3 * N; N4 = P4 * N

[0025] P1 = S1 / (S1 + S2 + S3 + S4)

[0026] P2 = S2 / (S1 + S2 + S3 + S4)

[0027] P3 = S3 / (S1 + S2 + S3 + S4)

[0028] P4 = S4 / (S1 + S2 + S3 + S4)

[0029] Calculate the proportion of the number of obstacles in each safety area respectively, as follows:

[0030] Ratio1 = Count1 / N1; Ratio2 = Count2 / N2; Ratio3 = Count3 / N3; Ratio4 = Count4 / N4

[0031] Among them, N1 represents the total number of scan points in the front area; N2 represents the total number of scan points in the left area; N3 represents the total number of scan points in the rear area; N4 represents the total number of scan points in the right area; N represents the total number of scan points within one cycle of the navigation radar; P1 represents the proportion of the front area in the total area; P2 represents the proportion of the left area in the total area; P3 represents the proportion of the rear area in the total area; P4 represents the proportion of the right area in the total area; S1 represents the area of the front area; S2 represents the area of the left area; S3 represents the area of the rear area; S4 represents the area of the right area; Ratio1 represents the proportion of the number of obstacles in the front area; Count1 represents the number of obstacles in the front area; Ratio2 represents the proportion of the number of obstacles in the left area; Count2 represents the number of obstacles in the left area; Ratio3 represents the proportion of the number of obstacles in the rear area; Count3 represents the number of obstacles in the rear area; Ratio4 represents the proportion of the number of obstacles in the right area; Count4 represents the number of obstacles in the right area.

[0032] Preferably, in the obstacle avoidance step, if the proportion exceeds the preset ratio, an alarm prompt is given, specifically including:

[0033] If the proportion exceeds the preset ratio, the sound and / or frequency are adjusted according to the vehicle driving speed and then an alarm prompt is given;

[0034] Preferably, in the automatic mode, the driving speed is controlled, specifically including:

[0035] Deceleration control or stop control is performed according to the proportion range.

[0036] On the other hand, an AGV obstacle avoidance system for navigation radar scanning includes:

[0037] An obstacle avoidance module for obtaining the polar coordinates of the current scanning point, converting the polar coordinates into the coordinates of the rectangular coordinate system; determining whether the coordinates of the rectangular coordinate system are located in one of the four safety regions, and if so, incrementing the number of obstacle points in the corresponding safety region by 1; after the completion of the current scanning period, calculating the proportion of the number of obstacle points in each safety region, and making a judgment on each proportion based on the driving direction of the vehicle. If the proportion exceeds the preset ratio, an alarm prompt is given; the four safety regions include the front region, the left region, the rear region, and the right region.

[0038] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention divides the detection area into the front region, the left region, the rear region, and the right region, and converts the polar coordinates of the scanning points emitted by the navigation radar into the coordinates of the rectangular coordinate system; judges the region where the scanning points are located according to the coordinates, and separately counts the number of obstacle points in the front region, the left region, the rear region, and the right region; counts the proportion of the number of obstacle points in each safety region within the scanning period. If the proportion exceeds the preset ratio, an alarm prompt is given, improving the recognition accuracy;

[0040] (2) In the manual mode, the present invention can adjust the areas of the front region, the left region, the rear region, and the right region according to the driving direction; in the automatic mode, it can adjust the areas of the front region, the left region, the rear region, and the right region according to the driving direction and the driving speed, realizing increasing the safe stopping distance at the position facing the driving direction (such as increasing the area of the front region when moving forward and increasing the area of the rear region when moving backward, etc.) and when the speed is relatively fast to better avoid collisions;

[0041] (3) Before detecting obstacles, the present invention detects the navigation radar itself to judge whether the mirror is dirty or abnormal, avoiding problems caused by inaccurate detection due to this;

[0042] (4) The sound volume and frequency of the audible and visual alarm of the present invention can be adjusted according to the driving speed, enabling the AGV driver or other personnel around the AGV to respond quickly;

[0043] (5) The present invention first judges the driving mode of the AGV. For the automatic mode, after detecting an obstacle, in addition to giving an audible and visual alarm, it will also perform driving speed control to control deceleration or stop, thus meeting the detection requirements of various driving modes. Description of the Drawings

[0044] Figure 1It is the basic flowchart of the AGV obstacle avoidance method for navigation radar scanning in the embodiment of the present invention;

[0045] Figure 2 It is the detailed flowchart of the AGV obstacle avoidance method for navigation radar scanning in the embodiment of the present invention;

[0046] Figure 3 It is the schematic diagram of the navigation radar mirror surface in the embodiment of the present invention;

[0047] Figure 4 It is the schematic diagram of area division during the detection of the navigation radar mirror surface in the embodiment of the present invention;

[0048] Figure 5 It is the flowchart of the navigation radar mirror surface detection in the embodiment of the present invention;

[0049] Figure 6 It is the top view of the safety area during the navigation radar scanning when the AGV is running in the embodiment of the present invention;

[0050] Figure 7 It is the top view of the safety area in the rectangular coordinate system during the navigation radar scanning when the AGV is running in the embodiment of the present invention;

[0051] Figure 8 It is the structural block diagram of the AGV obstacle avoidance system for navigation radar scanning in the embodiment of the present invention. Specific Embodiments

[0052] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0053] In the description of the present invention, it should be noted that the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitations, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0054] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the step identifiers S101, S102, S103, etc. are only used for convenient expression and do not represent the execution order, and the corresponding execution order can be adjusted as needed.

[0055] See Figure 1 and Figure 2 As shown, an AGV obstacle avoidance method for navigation radar scanning includes:

[0056] Navigation radar mirror anomaly judgment step S101, judge whether the navigation radar mirror is abnormal, if abnormal, give an alarm prompt; otherwise, enter the driving mode judgment step S102.

[0057] Driving mode judgment step S102, obtain the driving mode of the vehicle, if it is the manual mode, enter the manual mode obstacle avoidance step S103, otherwise, enter the automatic mode obstacle avoidance step S104;

[0058] Manual mode obstacle avoidance step S103, obtain the polar coordinates of the current scanning point, convert the polar coordinates into the coordinates of the rectangular coordinate system; judge whether the coordinates of the rectangular coordinate system are located in one of the four safety regions, if so, add 1 to the number of obstacle points in the corresponding safety region; after the current scanning period is completed, calculate the proportion of the number of obstacle points in each safety region, and judge each proportion based on the driving direction of the vehicle, if the proportion exceeds the preset ratio, give an alarm prompt; the four safety regions include the front region, the left region, the rear region and the right region;

[0059] Automatic mode obstacle avoidance step S104, obtain the polar coordinates of the current scanning point, convert the polar coordinates into the coordinates of the rectangular coordinate system; judge whether the coordinates of the rectangular coordinate system are located in one of the four safety regions, if so, add 1 to the number of obstacle points in the corresponding region; after the current scanning period is completed, calculate the proportion of the number of obstacle points in each region, and judge each proportion based on the vehicle's forward direction, if the proportion exceeds the preset ratio, give an alarm prompt and control the driving speed.

[0060] In this embodiment, the execution subject of an AGV obstacle avoidance method for navigation radar scanning is the AGV controller. The navigation radar is installed on the top of the AGV.

[0061] See Figures 3 to 5 As shown, the specific implementation of the navigation radar mirror anomaly judgment step S101 is as follows.

[0062] Let the number of points scanned in one cycle of the navigation radar be N (one cycle is one rotation, and each scanning point is separated by a certain angle theta, N = 360 / theta). The polar coordinates Ni of each scanning point are expressed as (r, Theta), where r represents the distance from the scanning point to the center point of the navigation radar, and Theta represents the angle of the scanning point. Since the center point of the navigation radar is at a fixed distance L from the mirror, the safe area of the navigation radar is judged to be a circle with a radius of L+L_corr, where L_corr is an additional detection range set according to the actual setting. The safe area is divided into four areas: [0, 90°], (90°, 180°], (0, -90°], and (-90°, -180°). The total number of points scanned in each area is N1, N2, N3, and N4 (N = 360 / 4 / Theta). When the r of a certain scanning point is less than L+L_corr , then the scanning point is considered to be the point where the obstacle touches the safety area. According to its angle Theta, the count of the corresponding area is increased by 1. For example, if the angle is 45°, the obstacle point count1 in the [0, 90°] safety area is increased by 1. After the radar scans a circle, count1, count2, count3 and count4 of the four safety areas are counted respectively. When the count of one area exceeds 10% of the total scanning points of the current area or two or more areas exceed 5%, and this proportion continues for more than a certain set period T N When the navigation head is dirty or there is a problem with the mirror, the AGV vehicle will give an audible and visual alarm.

[0063] Furthermore, in the manual mode obstacle avoidance step 103 or the automatic mode obstacle avoidance step 104, the polar coordinates (r, Theta) of the current scanning point are first obtained, and the polar coordinates are converted into the coordinates (x, y) of the rectangular coordinate system. Figure 6 and Figure 7 shown.

[0064] The areas (length and / or width) of the front, left, rear, and right regions can be set according to the application. Specifically, when the vehicle is traveling forward, the risk of collision in the front region is greater than in other directions, so the width of the front region is set to be greater than the width of the rear region, so that the area of the front region is larger than the area of the rear region, thereby increasing the safe stopping distance; when the vehicle is traveling backward, the risk of collision in the rear region is greater than in other directions, so the width of the rear region is greater than the width of the front region; when the vehicle is turning left, the length of the left region is greater than the right region; when the vehicle is turning right, the length of the right region is greater than the left region.

[0065] It should be noted that in the obstacle avoidance step 103 in manual mode, the front area, left area, rear area, and right area can be set as static areas. In the obstacle avoidance step 104 in automatic mode, the length / width of each safety area can be dynamically adjusted based on the vehicle speed, etc. on the basis of the static area. In this embodiment, the side in the same direction as the horizontal plane is defined as the length of the area, and vice versa, it is the width.

[0066] Specifically, in the obstacle avoidance step 103 in manual mode or the obstacle avoidance step 104 in automatic mode, the safety area is a matrix area; determine whether the coordinates in the rectangular coordinate system are located in one of the set four safety areas. If so, increment the number of obstacle points in the corresponding area by 1, specifically including:

[0067] If (-L 横向前 / 2) <= x <= (L 横向前 / 2) and 0 <= y <= L 纵向前 , it is considered that the point cloud data of the obstacle has invaded the front safety area, it is determined that the coordinates in the rectangular coordinate system are located in the front area, and increment the number of obstacle points Count1 in the front area by 1; where x represents the abscissa value; y represents the ordinate value; L 横向前 represents the length of the front area; L 纵向前 represents the width of the front area;

[0068] If (-L 横向后 / 2) <= x <= (L 横向后 / 2) and -L 纵向后 <= y < 0, it is considered that the point cloud data of the obstacle has invaded the rear safety area, it is determined that the coordinates in the rectangular coordinate system are located in the rear area, and increment the number of obstacle points Count2 in the rear area by 1; where L 横向后 represents the length of the rear area; L 纵向后 represents the width of the rear area;

[0069] If ((-L 横向左 -L 横向前 ) / 2) <= x < (-L 横向前 / 2) and (-L 纵向左 / 2) <= y <= (L 纵向左 / 2), it is considered that the point cloud data of the obstacle has invaded the left safety area, it is determined that the coordinates in the rectangular coordinate system are located in the left area, and increment the number of obstacle points Count3 in the left area by 1; where L 横向左 represents the length of the left area; L 纵向左 represents the width of the left area;

[0070] If (L 横向前 / 2) < x <= ((L 横向右 +L 横向前 ) / 2) and (-L 纵向右 / 2) <= y <= (L 纵向右 / 2), it is considered that the point cloud data of the obstacle invades the safe area on the right, it is judged that the coordinates in the rectangular coordinate system are in the right area, and the number of obstacle points Count4 in the right area is incremented by 1; where L 横向右 represents the length of the right area; L 纵向右 represents the width of the right area.

[0071] Furthermore, calculate the proportion of the number of obstacle points in each area, specifically including:

[0072] Calculate the total number of scanned points in each safe area respectively as follows:

[0073] N1 = P1 * N; N2 = P2 * N; N3 = P3 * N; N4 = P4 * N

[0074] P1 = S1 / (S1 + S2 + S3 + S4)

[0075] P2 = S2 / (S1 + S2 + S3 + S4)

[0076] P3 = S3 / (S1 + S2 + S3 + S4)

[0077] P4 = S4 / (S1 + S2 + S3 + S4)

[0078] Among them, N1 represents the total number of scanned points in the front area; N2 represents the total number of scanned points in the left area; N3 represents the total number of scanned points in the rear area; N4 represents the total number of scanned points in the right area; N represents the total number of scanned points in one cycle of the navigation radar; P1 represents the proportion of the front area in the total area; P2 represents the proportion of the left area in the total area; P3 represents the proportion of the rear area in the total area; P4 represents the proportion of the right area in the total area; S1 represents the area of the front area; S2 represents the area of the left area; S3 represents the area of the rear area; S4 represents the area of the right area.

[0079] Then the proportion of the number of obstacle points in the front area Ratio1 = Count1 / N1, the proportion of the number of obstacle points in the left area Ratio2 = Count2 / N2, the proportion of the number of obstacle points in the lower area Ratio3 = Count3 / N3, and the proportion of the number of obstacle points in the right area Ratio4 = Count4 / N4.

[0080] In the manual mode obstacle avoidance step 103, when the driving direction is forward, if the proportion Ratio1 of the number of obstacle points in the front area exceeds 5%, or the total proportion of the left, right, and rear areas exceeds 20%, and this situation lasts for more than a certain set period T N, it can be considered that the navigation head has scanned an obstacle with a risk of accidental collision, and the vehicle gives an audible and visual alarm reminder. When the driving direction is backward, left or right, the ratio can be set according to specific needs.

[0081] Further, in the manual mode obstacle avoidance step 103, if the ratio exceeds the preset ratio, an alarm prompt is given, specifically including:

[0082] Set the frequency and sound volume of the audible and visual broadcast according to the vehicle speed. For example, if the vehicle speed is differentiated every 300 mm / s, the volume starts to accumulate from 50%, and the audible and visual alarm frequency F is set to change with the vehicle speed. Specifically, Volume = 50% + (50% * Vel) / 1500, Fact = ((0.5 * Vel) / 1500 + 1) * F, where Vel represents the vehicle speed.

[0083] Further, in the automatic mode obstacle avoidance step S104, the length and / or width of the front area, rear area, left area, and right area can be automatically adjusted based on the vehicle driving speed and driving direction.

[0084] For the front area, the AGV vehicle can dynamically adjust the safety area of the vehicle's navigation radar according to the vehicle speed. For example, when the vehicle speed exceeds 1500 mm / s, the front area is set to 110% of the maximum static area. When the vehicle speed is lower than 300 mm / s, the front area is set to 50% of the maximum static area. In other cases, the safety area size is changed every 100 mm / s according to the vehicle speed. The specific dynamic formula for scaling the front area can be: (50% + Vel * (60% / 1500)), where Vel represents the vehicle speed.

[0085] Further, when the AGV vehicle turns left, the right area will be appropriately reduced according to the steering angle of the vehicle and compensated to the left area, with a maximum compensation of 1 / 4 of the area. When the vehicle turns right, the left area will be appropriately reduced according to the steering angle of the vehicle and compensated to the right area, with a maximum compensation of 1 / 4 of the area. The proportion of the changing area is ((25% * Theta) / 90).

[0086] In the automatic mode obstacle avoidance step 103, when the driving direction is forward, if the ratio of the number of obstacle points in the front area Ratio1 exceeds 5%, or the total ratio of the left, right, and rear areas exceeds 20%, and this situation lasts for more than a certain set period T N , it can be considered that the navigation head has scanned an obstacle with a risk of accidental collision, and the vehicle gives an audible and visual alarm reminder. When the driving direction is backward, left or right, the ratio can be set according to specific needs.

[0087] Further, when it is determined that there is a collision risk in the navigation radar, the range for triggering an emergency stop of the vehicle will be adjusted according to the vehicle speed. When the driving direction is forward, if the count in the front area exceeds 28% - (4% * (Vel / 300)) of the total number of scanned points in the current area, or three safety distance thresholds q1, q2, and q3 are set (such as being defaulted to the 90%, 70%, and 50% positions of the width of the front area respectively), calculate the number of scanned points falling into these three areas. If the count of q1 exceeds 20% of the total number of scanned points in the front area, or the count of q1 exceeds 15% of the total number of scanned points in the front area, or the count of q2 exceeds 10% of the total number of scanned points in the front area, the vehicle will also trigger an emergency stop. In other cases, the vehicle will be given a gentle braking, and at the same time, the vehicle will give corresponding sound and light alarm reminders.

[0088] See Figure 8 As shown, an AGV obstacle avoidance system for navigation radar scanning includes:

[0089] A navigation radar mirror abnormality judgment module 801, used to judge whether the navigation radar mirror is abnormal. If it is abnormal, an alarm prompt is given; otherwise, the driving mode judgment module 802 is executed;

[0090] A driving mode judgment module 802, used to obtain the driving mode of the vehicle. If it is the manual mode, the manual mode obstacle avoidance module 803 is executed; otherwise, it enters the automatic mode obstacle avoidance module 804;

[0091] A manual mode obstacle avoidance module 803, used to obtain the polar coordinates of the current scanned point, and convert the polar coordinates into the coordinates of the rectangular coordinate system; judge whether the coordinates of the rectangular coordinate system are located in one of the four safety areas. If so, add 1 to the number of obstacle points in the corresponding safety area; after the current scanning cycle is completed, calculate the proportion of the number of obstacle points in each safety area, and judge each proportion based on the driving direction of the vehicle. If the proportion exceeds the preset ratio, an alarm prompt is given; the four safety areas include the front area, the left area, the rear area, and the right area;

[0092] An automatic mode obstacle avoidance module 804, used to obtain the polar coordinates of the current scanned point, and convert the polar coordinates into the coordinates of the rectangular coordinate system; judge whether the coordinates of the rectangular coordinate system are located in one of the four safety areas. If so, add 1 to the number of obstacle points in the corresponding area; after the current scanning cycle is completed, calculate the proportion of the number of obstacle points in each area, and judge each proportion based on the vehicle's forward direction. If the proportion exceeds the preset ratio, the driving speed is controlled.

[0093] The execution entity of an AGV obstacle avoidance system for navigation radar scanning is an AGV controller. The specific implementation of each module is the same as that of an AGV obstacle avoidance method for navigation radar scanning, and this embodiment will not be repeated here.

[0094] The above are only the preferred specific embodiments of the present invention; however, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its improved concept, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. An AGV obstacle avoidance method for navigation radar scanning, characterized in that, Including: An obstacle avoidance step, obtaining the polar coordinates of the current scanning point, and converting the polar coordinates into the coordinates of the rectangular coordinate system; determining whether the coordinates of the rectangular coordinate system are located in one of the four safe areas, and if so, incrementing the number of obstacle points in the corresponding safe area by 1; after the current scanning cycle is completed, calculating the proportion of the number of obstacle points in each safe area, and making a judgment on each proportion based on the driving direction of the vehicle. If the proportion exceeds the preset ratio, an alarm prompt is given. The four safe areas include a front area, a left area, a rear area, and a right area.

2. The AGV obstacle avoidance method based on navigation radar scanning according to claim 1, wherein Before the obstacle avoidance step, it further includes: A navigation radar mirror abnormality judgment step, judging whether the navigation radar mirror is abnormal. If it is abnormal, an alarm prompt is given; otherwise, the obstacle avoidance step is entered.

3. The AGV obstacle avoidance method for navigation radar scanning according to claim 2, wherein, The navigation radar mirror abnormality judgment step specifically includes: Setting the safe area of the navigation radar as a circle with a radius of L + L_corr, and dividing this safe area into four areas: [0, 90°], (90°, 180°], (0, -90°], and (-90°, -180°); where L represents the fixed distance between the center point of the radar and the mirror surface; L_corr is the preset detection distance. Obtaining the polar coordinates (r, Theta) of the current scanning point, judging the safe area to which the scanning point belongs based on Theta, and when r is less than L + L_corr, incrementing the number of obstacle points in the corresponding safe area by 1; where r represents the distance from the scanning point to the center point, and Theta represents the angle of the scanning point. After the radar scans one circle, obtaining the number of obstacle points in each safe area, and calculating the quotient of the number of obstacle points in each safe area and the total number of scanning points in the corresponding safe area to obtain the proportion. If the proportion of one of the safe areas exceeds the first preset value or the total proportion of two or more safe areas exceeds the second preset value, and the duration exceeds the first preset time, it is judged that the navigation radar mirror is abnormal.

4. The AGV obstacle avoidance method based on navigation radar scanning according to claim 1, characterized in that It further includes: A driving mode judgment step, obtaining the driving mode of the vehicle. If it is the manual mode, the obstacle avoidance step is executed. If it is the automatic mode, the obstacle avoidance step is executed and the driving speed is controlled.

5. The AGV obstacle avoidance method based on navigation radar scanning according to claim 1, characterized in that, In the obstacle avoidance step, when the vehicle is driving forward, the width of the front area is greater than the width of the rear area; when the vehicle is driving backward, the width of the front area is less than the width of the rear area. When the vehicle is turning left, the length of the left area is greater than the right area; when the vehicle is turning right, the length of the right area is greater than the left area.

6. The AGV obstacle avoidance method based on navigation radar scanning according to claim 4, characterized in that, If it is the automatic mode, the length and / or width of the front area, rear area, left area, and right area are automatically adjusted based on the driving speed and driving direction of the vehicle.

7. The AGV obstacle avoidance method based on navigation radar scanning according to claim 1, characterized in that, In the obstacle avoidance step, the safe area is a matrix area; determining whether the coordinates of the rectangular coordinate system are located in one of the set four safe areas, and if so, incrementing the number of obstacle points in the corresponding area by 1, specifically including: If (-L 横向前 / 2) <= x <= (L 横向前 / 2) and 0 <= y <= L 纵向前 , then it is determined that the coordinates in the rectangular coordinate system are located in the front area, and the number of obstacles in the front area is incremented by 1; where x represents the abscissa value; y represents the ordinate value; L 横向前 represents the length of the front area; L 纵向前 represents the width of the front area; If (-L 横向后 / 2) <= x <= (L 横向后 / 2) and -L 纵向后 <= y < 0, it is determined that the coordinates in the rectangular coordinate system are located in the rear area, and the number of obstacle points in the rear area is incremented by 1; where L 横向后 represents the length of the rear area; L 纵向后 represents the width of the rear area; If ((-L 横向左 -L 横向前 ) / 2) <= x < (-L 横向前 / 2) and (-L 纵向左 / 2) <= y <= (L 纵向左 / 2), then it is determined that the coordinates in the rectangular coordinate system are located in the left region, and the number of obstacle points in the left region is incremented by 1; where L 横向左 represents the length of the left region; L 纵向左 represents the width of the left region; If (L 横向前 / 2) < x <= ((L 横向右 + L 横向前 ) / 2) and (-L 纵向右 / 2) <= y <= (L 纵向右 / 2), then it is determined that the coordinates in the rectangular coordinate system are located in the right region, and the number of obstacle points in the right region is incremented by 1; where L 横向右 represents the length of the right region; L 纵向右 represents the width of the right region.

8. The AGV obstacle avoidance method for navigation radar scanning according to claim 1, wherein In the obstacle avoidance step, calculating the proportion of the number of obstacle points in each area, specifically including: Calculating the total number of scanning points in each safe area respectively, as follows: N1 = P1 * N; N2 = P2 * N; N3 = P3 * N; N4 = P4 * N P1 = S1 / (S1 + S2 + S3 + S4) P2 = S2 / (S1 + S2 + S3 + S4) P3 = S3 / (S1 + S2 + S3 + S4) P4 = S4 / (S1 + S2 + S3 + S4) Calculate the proportion of the number of obstacle points in each safety area respectively, as follows: Ratio1 = Count1 / N1; Ratio2 = Count2 / N2; Ratio3 = Count3 / N3; Ratio4 = Count4 / N4 Wherein, N1 represents the total number of scanned points in the front area; N2 represents the total number of scanned points in the left area; N3 represents the total number of scanned points in the rear area; N4 represents the total number of scanned points in the right area; N represents the total number of scanned points within one cycle of the navigation radar; P1 represents the proportion of the front area in the total area; P2 represents the proportion of the left area in the total area; P3 represents the proportion of the rear area in the total area; P4 represents the proportion of the right area in the total area; S1 represents the area of the front area; S2 represents the area of the left area; S3 represents the area of the rear area; S4 represents the area of the right area; Ratio1 represents the proportion of the number of obstacle points in the front area; Count1 represents the number of obstacle points in the front area; Ratio2 represents the proportion of the number of obstacle points in the left area; Count2 represents the number of obstacle points in the left area; Ratio3 represents the proportion of the number of obstacle points in the rear area; Count3 represents the number of obstacle points in the rear area; Ratio4 represents the proportion of the number of obstacle points in the right area; Count4 represents the number of obstacle points in the right area.

9. The AGV obstacle avoidance method based on navigation radar scanning according to claim 4, wherein In the obstacle avoidance step, if the proportion exceeds the preset ratio, an alarm prompt is given, specifically including: If the proportion exceeds the preset ratio, the sound and / or frequency are adjusted according to the vehicle driving speed and then an alarm prompt is given; In the automatic mode, the vehicle driving speed is controlled, specifically including: Deceleration control or stop control is performed according to the proportion range.

10. An AGV obstacle avoidance system for navigation radar scanning, characterized in that, Including: An obstacle avoidance module, which is used to obtain the polar coordinates of the current scanned point, convert the polar coordinates into the coordinates of the rectangular coordinate system; judge whether the coordinates of the rectangular coordinate system are located in one of the four safety areas, if so, increment the number of obstacle points in the corresponding safety area by 1; after the current scanning cycle is completed, calculate the proportion of the number of obstacle points in each safety area, and judge each proportion based on the driving direction of the vehicle. If the proportion exceeds the preset ratio, an alarm prompt is given; The four safety areas include a front area, a left area, a rear area, and a right area.

Images