A tray robot automatic positioning method applied to an intelligent warehouse

Abstract

The application discloses a tray robot automatic positioning method applied to an intelligent warehouse, and comprises the following steps: a tray robot walks to one side of a tray, and makes the front ends of the two outer walking arms of the tray robot correspond to the front ends of the two outer supporting feet of the tray one by one; parallelism deviation analysis is conducted on the straight line where the front ends of the two walking arms of the tray robot are located and the straight line where the front ends of the corresponding supporting feet are located through an upstream control system, so as to judge whether the front ends of the walking arms and the front ends of the supporting feet are parallel; center point deviation analysis is conducted between the center points of the front ends of the two walking arms of the tray robot and the center points of the front ends of the corresponding supporting feet through the upstream control system, so as to judge whether deviation occurs between the center points of the front ends of the two walking arms of the tray robot and the center points of the front ends of the corresponding supporting feet; through the judgment, the tray robot is caused to execute a lifting tray action, or the tray robot is caused to be corrected. The application can automatically position, improve positioning accuracy, and realize smooth lifting of goods on the tray.

Description

Technical Field

[0001] This invention relates to a positioning method for a pallet robot, and more particularly to an automatic positioning method for a pallet robot applied in a smart warehouse. Background Technology

[0002] Existing pallet robots are used for handling palletized goods. Typically, a pallet robot 1 (such as...) Figure 1 (As shown) includes a vehicle body 11 and two forks 12. The vehicle body 11 has three traveling arms 13, and a traveling channel 14 is provided between adjacent traveling arms 13. The forks 12 are installed in the traveling channel 14 and can move within the traveling channel 14. Figure 1 As shown, the pallet 2, which holds the goods, has three support legs 21 and two grooves 22 on each of its four sides. Each groove 22 is located between two adjacent support legs 21. The two grooves 22 facilitate the forks 12 of the pallet robot 1 to enter from four directions on the pallet 2. During operation, the goods are placed on the pallet 2. When the pallet robot 1 moves to one side of the pallet 2, the two moving forks 12 of the pallet robot 1 align with the two grooves 22 on that side of the pallet 2. The two forks 12 detach from the vehicle body 11 and move under the pallet 2, that is, the two forks 12 extend into the two grooves 22. After the forks 12 lift the pallet 2 and the goods, the forks 12 should remain stationary relative to the ground. The vehicle body moves under the pallet 2. After the forks 12 reconnect with the vehicle body, the forks 12 lower the pallet 2 and the goods to the vehicle body for support, completing the loading process. Finally, the pallet robot 1 places the goods at the target location.

[0003] During the aforementioned cargo handling process, if the pallet robot 1 is not positioned accurately, or if the two walking arms 13 on the outside of the pallet robot 1 do not correspond accurately with the two supporting legs 21 on the outside of the pallet 2, the two moving forks 12 of the pallet robot 1 will block the three supporting legs 21 of the pallet 2 during the extension process. In severe cases, this may cause damage to the pallet 2, or even cause the goods on the pallet 2 to tilt, resulting in the goods falling off the pallet 2 and hitting people or objects, which may easily cause serious safety hazards and economic losses. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide an automatic positioning method for pallet robots applied to smart warehouses. This automatic positioning method for pallet robots applied to smart warehouses can automatically position themselves, improve positioning accuracy, and enable pallet robots to smoothly lift goods on pallets.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An automatic positioning method for pallet robots applied in smart warehouses, characterized by the following steps:

[0007] (1) The pallet robot walks to one side of the pallet and makes the front ends of the two outermost walking arms of the pallet robot correspond one-to-one with the front ends of the two outermost supporting feet of the pallet;

[0008] (2) First, the parallelism deviation analysis of the straight line where the front end of the two walking arms of the pallet robot is located and the straight line where the front end of the corresponding support foot is located is performed through the upstream control system to determine whether the front end of the walking arm and the front end of the support foot are parallel.

[0009] (3) Then, the center point deviation analysis between the front center point of the two walking arms of the pallet robot and the front center point of the corresponding support foot is performed through the upstream control system to determine whether there is a deviation between the front center point of the two walking arms of the pallet robot and the front center point of the corresponding support foot.

[0010] (4) If the front end of the walking arm is parallel to the front end of the supporting foot, and the center point of the front end of the walking arm is aligned with the center point of the front end of the corresponding supporting foot, then the pallet robot starts to perform the lifting action; if the front end of the walking arm is not parallel to the front end of the corresponding supporting foot, and / or the center point of the front end of the walking arm is deviated from the center point of the front end of the corresponding supporting foot, then the pallet robot executes the corresponding correction action command to correct the deviation of the pallet robot.

[0011] The definitions of "front" and "rear" above are as follows: the end of the walking arm that is closer to the supporting foot is the front, and the end of the walking arm that is farther away from the supporting foot is the rear.

[0012] The parallelism mentioned above refers to the parallelism between the straight line at the front end of the outermost walking arm of the pallet robot and the straight line at the front end of the outermost supporting foot of the pallet.

[0013] The aforementioned center point deviation refers to the deviation between the center point between the two ends of the outermost walking arm of the pallet robot and the center point between the two ends of the supporting legs of the pallet.

[0014] In the preferred embodiment, in step (1), the upstream control system pre-sets a predetermined deviation angle range and a predetermined straight-line distance range between the center points of the front ends of the two walking arms and the center points of the front ends of the corresponding support feet. The center points of the front ends of the two outermost walking arms of the pallet robot are respectively equipped with obstacle avoidance radar. The pallet robot scans the two endpoints and the center point of the front ends of the two outermost support feet of the pallet through the obstacle avoidance radar, and calculates and analyzes the angles between the two endpoints and the center point of the front ends of the support feet and the obstacle avoidance radar, thereby obtaining the real-time angles and real-time straight-line distances between the front ends of the two outermost walking arms of the pallet robot and the front ends of the two outermost support feet of the pallet. In step (2), the real-time angles are compared with the predetermined deviation angle range to determine the parallelism deviation between the front ends of the walking arms and the front ends of the corresponding support feet. In step (3), the real-time straight-line distances are compared with the predetermined straight-line distance range to determine the deviation between the center points of the front ends of the walking arms and the center points of the front ends of the corresponding support feet.

[0015] In a further preferred embodiment, the step (2) of determining the parallelism deviation between the front end of the walking arm and the front end of the corresponding supporting foot is as follows: (2-1) When the real-time angle is within the predetermined deviation angle range, it can be determined that the front end of the walking arm and the front end of the supporting foot are parallel, that is, the parallelism between the front end of the walking arm and the front end of the supporting foot is not deviated; (2-2) When the real-time angle exceeds the predetermined deviation angle range, it can be determined that the front end of the walking arm and the front end of the supporting foot are not parallel, that is, the parallelism between the front end of the walking arm and the front end of the supporting foot is deviated.

[0016] In step (3), the steps for determining the deviation between the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are as follows: (3-1) If the real-time straight distance is within the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are not deviated; (3-2) If the real-time straight distance exceeds the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are deviated.

[0017] If the conditions in steps (2-1) and (3-1) are met, then let the pallet robot start to perform the pallet lifting action;

[0018] If one or both of the situations in steps (2-2) and (3-2) occur, the pallet robot will execute the corresponding correction action command to correct its deviation.

[0019] In a further preferred embodiment, in step (4), if the situation in step (2-2) occurs, the parallelism deviation angle of the pallet robot is obtained by calculation, and a parallelism deviation correction action command for the pallet robot is formed; if the situation in step (2-2) does not occur, the deviation between the center point of the front end of the walking arm and the center point of the front end of the corresponding supporting foot is re-evaluated.

[0020] If the situation in step (3-2) occurs, the center point deviation distance of the pallet robot is obtained by calculation, and the center point deviation correction action command of the pallet robot is generated. Then, the parallelism deviation correction action command and / or center point deviation correction action command are sent to the pallet robot through the upstream control system, so that the pallet robot can perform the corresponding actions to adjust the parallelism deviation and / or center point deviation between the front end of the walking arm and the front end of the corresponding support foot.

[0021] In a further optimized solution, step (5) is also included: after adjusting the deviation between the front end of one set of walking arms and the front end of the corresponding support foot, it is necessary to check whether there is a parallelism deviation and a center point deviation between the front end of the other set of walking arms and the front end of the corresponding support foot, in accordance with steps (2) to (4) above.

[0022] (5-1) If the conditions of steps (2-1) and (3-1) are met, then let the pallet robot start to perform the pallet lifting action;

[0023] (5-2) The upstream control system pre-sets a predetermined number of deviation corrections. If the conditions of steps (2-1) and (3-1) are not met, it is determined whether the number of real-time corrections exceeds the predetermined number of deviation corrections. If the number of real-time corrections does not exceed the predetermined number of deviation corrections, steps (2) to (4) above are executed. If the number of real-time corrections exceeds the predetermined number of deviation corrections, the pallet robot will issue an alarm.

[0024] In step (5) above, after adjusting the deviation between the front end of one set of walking arms and the front end of the corresponding support foot, the deviation between the front end of the other set of walking arms and the front end of the corresponding support foot must also be checked again to prevent the other set from changing due to the adjustment of one set.

[0025] In a further preferred embodiment, in step (2), the parallelism deviation between the front end of the outermost walking arm and the front end of the corresponding outermost supporting foot is calculated using a parallelism judgment formula; the parallelism judgment formula is derived as follows:

[0026] Assume the distance between the two endpoints A and B of the front end of the pallet's support leg is AB, and O2 is the center point of AB;

[0027] The distance between the two endpoints C and D at the front end of the walking arm is CD, and O1 is the center point of CD;

[0028] The distance returned by the obstacle avoidance radar after detecting point A is O1A;

[0029] The distance returned by the obstacle avoidance radar after detecting point B is O1B;

[0030] The angle returned by the obstacle avoidance radar from point B is ∠BO1O2, denoted as γ;

[0031] Let the horizontal angle from AB to CD be ∠ABO1, denoted as α; and the horizontal angle from CD to AB be ∠DO1B, denoted as β.

[0032] According to the Pythagorean theorem and the inverse cosine theorem: cosα = (AB) 2 +O1B 2 -O1A 2 ) / 2*AB*O1B, α=arccosα, and then calculate the angle of α;

[0033] Calculate the angle of β: β = 90° - γ;

[0034] Calculate the parallelism deviation value: α - β;

[0035] When the value of (α-β) is within the predetermined deviation angle range, AB is determined to be parallel to CD;

[0036] When the value of (α-β) is not within the predetermined deviation angle range, it is determined that AB and CD are not parallel.

[0037] In a further preferred embodiment, in step (3), the center point deviation between the front end of the outermost walking arm and the front end of the corresponding outermost supporting foot is calculated using a center point deviation judgment formula; the center point deviation judgment formula is derived as follows:

[0038] The upstream control system pre-sets the predetermined straight-line distance between the front ends of the two walking arms and the front ends of the corresponding support feet as O1O2';

[0039] According to the Pythagorean theorem: O1O2 2 =O2B 2 +O1B 2 -2*O2B*O1B*cosα, calculate the distance between O1 and O2;

[0040] When the value of (O1O2-O1O2') is within the predetermined straight-line distance range, it is determined that point O1 and point O2 are not deviated.

[0041] When the value of (O1O2-O1O2') exceeds the predetermined straight-line distance range, it is determined that point O1 and point O2 have deviated.

[0042] In a further preferred embodiment, the parallelism deviation correction action command is executed according to the following steps:

[0043] When α>β and the value of (α-β) is not within the predetermined deviation angle range, the pallet robot rotates clockwise by the deviation angle of (α-β).

[0044] When α < β and the value of (α - β) is not within the predetermined deviation angle range, the pallet robot rotates counterclockwise by the deviation angle of (α - β).

[0045] In a further preferred embodiment, the center point deviation correction action command is executed according to the following steps: the pallet robot rotates at a preset angle δ, causing the pallet robot to retreat to point E, with a retreat distance of O1E; then the pallet robot is straightened, and then the pallet robot moves forward to point O3, with a forward distance of EO3, so that the center point O1 at the front end of the pallet robot's walking arm moves to O3; the distance returned by the obstacle avoidance radar after detecting point O2 at point O1 is O1O2, and the distance returned by the obstacle avoidance radar after detecting point O2 at point O1 is O2O3;

[0046] Given O1O2 and O2O3, according to the Pythagorean theorem (O1O3... 2 =O1O22 -O2O3 2 Calculate the distance between O1 and O3: O1O3 = √(O1O2) 2 -O2O3 2 );

[0047] Given the preset angle δ, the distance O1E can be calculated using cosδ=O1O3 / O1E: O1E=O1O3 / cosδ;

[0048] According to the Pythagorean theorem: EO3 2 =O1E 2 -O1O3 2 The distance to EO3 can be calculated as follows: EO3 = √(O1E 2 -O1O3 2 ).

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] This invention uses obstacle avoidance radar to acquire the angle and distance between the front end of the outermost walking arm and the front end of the corresponding outermost supporting foot. This data is then uploaded to the upstream control system, which calculates the required rotation angle and displacement of the pallet robot and sends these instructions to the robot. This enables the pallet robot to automatically position itself, improving its accuracy and ensuring it can accurately position itself with the pallet, thus allowing it to smoothly lift the goods on the pallet. Furthermore, if the pallet robot fails to accurately position itself with the pallet after multiple corrections, it will promptly notify a worker via alarm, allowing for timely on-site intervention. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of the pallet robot and the pallet in the background technology and specific embodiments of the present invention;

[0052] Figure 2 This is a flowchart of a specific embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of parallelism judgment and center point deviation judgment in a specific embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the center point deviation correction action command in a specific embodiment of the present invention. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0056] like Figure 1-4As shown, the automatic positioning method for pallet robots applied to smart warehouses in this embodiment includes the following steps:

[0057] (1) The pallet robot 1 walks to one side of the pallet 2 and makes the front ends of the two outermost walking arms 13 of the pallet robot 1 correspond one-to-one with the front ends of the two outermost supporting feet 21 of the pallet 2;

[0058] (2) First, the parallelism deviation analysis of the straight line where the front end of the two walking arms 13 of the pallet robot 1 is located and the straight line where the front end of the corresponding support foot 21 is located is performed through the upstream control system to determine whether the front end of the walking arm 13 and the front end of the support foot 21 are parallel.

[0059] (3) Then, the center point deviation analysis between the front center point of the two walking arms 13 of the pallet robot 1 and the front center point of the corresponding support foot 21 is performed by the upstream control system to determine whether there is a deviation between the front center point of the two walking arms 13 of the pallet robot 1 and the front center point of the corresponding support foot 21.

[0060] (4) If the front end of the walking arm 13 is parallel to the front end of the support foot 21, and the center point of the front end of the walking arm 13 is aligned with the center point of the front end of the corresponding support foot 21, then the pallet robot 1 starts to perform the action of lifting the pallet 2; if the front end of the walking arm 13 is not parallel to the front end of the corresponding support foot 21, and / or the center point of the front end of the walking arm 13 deviates from the center point of the front end of the corresponding support foot 21, then the pallet robot 1 executes the corresponding correction action command to correct the deviation of the pallet robot 1.

[0061] The definitions of front and back are as follows: the end of the walking arm 13 that is close to the supporting foot 21 is the front, and the end of the walking arm 13 that is far away from the supporting foot 21 is the back.

[0062] The parallelism mentioned above refers to the parallelism between the straight line at the front end of the outermost walking arm 13 of the pallet robot 1 and the straight line at the front end of the outermost supporting leg 21 of the pallet 2.

[0063] The aforementioned center point deviation refers to the deviation between the center point of the two ends of the outermost walking arm 13 of the pallet robot 1 and the center point of the two ends of the front end of the supporting leg 21 of the pallet 2.

[0064] In step (1), the upstream control system pre-sets a predetermined deviation angle range and a predetermined straight-line distance range between the center points of the front ends of the two walking arms 13 and the center points of the front ends of the corresponding support legs 21. The center points of the front ends of the two outermost walking arms 13 of the pallet robot 1 are respectively equipped with obstacle avoidance radars 131. The pallet robot 1 scans the two endpoints and the center points of the front ends of the two outermost support legs 21 of the pallet 2 through the obstacle avoidance radars 131, and calculates and analyzes the angles between the two endpoints and the center points of the front ends of the support legs 21 and the obstacle avoidance radars 131, and obtains the real-time angles and real-time straight-line distances between the front ends of the two outermost walking arms 13 of the pallet robot 1 and the front ends of the two outermost support legs 21 of the pallet 2. In step (2), the real-time angles are compared with the predetermined deviation angle range to determine the parallelism deviation between the front ends of the walking arms 13 and the front ends of the corresponding support legs 21. In step (3), the real-time straight-line distances are compared with the predetermined straight-line distance range to determine the deviation between the center points of the front ends of the walking arms 13 and the center points of the front ends of the corresponding support legs 21.

[0065] In step (2), the steps for determining the parallelism deviation between the front end of the walking arm 13 and the front end of the corresponding support foot 21 are as follows: (2-1) When the real-time angle is within the predetermined deviation angle range, it can be determined that the front end of the walking arm 13 and the front end of the support foot 21 are parallel, that is, the parallelism between the front end of the walking arm 13 and the front end of the support foot 21 is not deviated; (2-2) When the real-time angle exceeds the predetermined deviation angle range, it can be determined that the front end of the walking arm 13 and the front end of the support foot 21 are not parallel, that is, the parallelism between the front end of the walking arm 13 and the front end of the support foot 21 is deviated.

[0066] In step (3), the steps for determining the deviation between the center point of the front end of the walking arm 13 and the center point of the front end of the corresponding support foot 21 are as follows: (3-1) If the real-time straight distance is within the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm 13 and the center point of the front end of the corresponding support foot 21 are not deviated; (3-2) If the real-time straight distance exceeds the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm 13 and the center point of the front end of the corresponding support foot 21 is deviated.

[0067] If the conditions in steps (2-1) and (3-1) are met, then let the pallet robot 1 start to perform the action of lifting the pallet 2;

[0068] If one or both of the situations in steps (2-2) and (3-2) occur, then the pallet robot 1 shall execute the corresponding correction action command to correct the deviation of the pallet robot 1.

[0069] In step (4), if the situation in step (2-2) occurs, the parallelism deviation angle of the pallet robot 1 is obtained by calculation, and the parallelism deviation correction action command of the pallet robot 1 is formed; if the situation in step (2-2) does not occur, the deviation between the front center point of the walking arm 13 and the front center point of the corresponding support foot 21 is re-evaluated.

[0070] If the situation in step (3-2) occurs, the center point deviation distance of the pallet robot 1 is obtained by calculation, and a center point deviation correction action command is generated for the pallet robot 1. Then, the parallelism deviation correction action command and / or center point deviation correction action command are sent to the pallet robot 1 through the upstream control system, so that the pallet robot 1 performs the corresponding action to adjust the parallelism deviation and / or center point deviation between the front end of the walking arm 13 and the front end of the corresponding support foot 21.

[0071] This embodiment also includes step (5), after adjusting the deviation between the front end of one set of walking arms 13 and the front end of the corresponding support foot 21, it is necessary to check whether the front end of the other set of walking arms 13 and the front end of the corresponding support foot 21 have parallelism deviation and center point deviation according to the above steps (2) to (4):

[0072] (5-1) If the conditions of steps (2-1) and (3-1) are met, then let the pallet robot 1 start to perform the action of lifting the pallet 2;

[0073] (5-2) The upstream control system pre-sets a predetermined number of deviation corrections. If the conditions of steps (2-1) and (3-1) are not met, it is determined whether the number of real-time corrections exceeds the predetermined number of deviation corrections. If the number of real-time corrections does not exceed the predetermined number of deviation corrections, steps (2) to (4) above are executed. If the number of real-time corrections exceeds the predetermined number of deviation corrections, the pallet robot 1 will issue an alarm.

[0074] In step (5) above, after adjusting the deviation between the front end of one set of walking arms 13 and the front end of the corresponding support foot 21, the deviation between the front end of the other set of walking arms 13 and the front end of the corresponding support foot 21 must also be checked again to prevent the other set from changing due to the adjustment of one set.

[0075] In step (2), the parallelism deviation between the front end of the outermost walking arm 13 and the front end of the corresponding outermost supporting foot 21 is calculated using the parallelism judgment formula; the parallelism judgment formula is derived as follows:

[0076] Assume that the distance between the two endpoints A and B of the front end of the support leg 21 of the tray 2 is AB, and O2 is the center point of AB;

[0077] The distance between the two endpoints C and D at the front end of the walking arm 13 is CD, and O1 is the center point of CD;

[0078] The distance returned after the obstacle avoidance radar 131 detects point A is O1A;

[0079] The distance returned after the obstacle avoidance radar 131 detects point B is O1B;

[0080] The angle returned by the obstacle avoidance radar 131 from point B is ∠BO1O2, denoted as γ;

[0081] Let the horizontal angle from AB to CD be ∠ABO1, denoted as α; and the horizontal angle from CD to AB be ∠DO1B, denoted as β.

[0082] According to the Pythagorean theorem and the inverse cosine theorem: cosα = (AB) 2 +O1B 2 -O1A 2 ) / 2*AB*O1B, α=arccosα, and then calculate the angle of α;

[0083] Calculate the angle of β: β = 90° - γ;

[0084] Calculate the parallelism deviation value: α - β;

[0085] When the value of (α-β) is within the predetermined deviation angle range, AB is determined to be parallel to CD;

[0086] When the value of (α-β) is not within the predetermined deviation angle range, it is determined that AB and CD are not parallel.

[0087] In step (3), the center point deviation between the front end of the outermost walking arm 13 and the front end of the corresponding outermost supporting foot 21 is calculated using the center point deviation judgment formula; the center point deviation judgment formula is derived as follows:

[0088] The upstream control system pre-sets the predetermined straight-line distance between the front ends of the two walking arms 13 and the front ends of the corresponding support feet 21 as O1O2';

[0089] According to the Pythagorean theorem: O1O2 2 =O2B 2 +O1B 2 -2*O2B*O1B*cosα, calculate the distance between O1 and O2;

[0090] When the value of (O1O2-O1O2') is within the predetermined straight-line distance range, it is determined that point O1 and point O2 are not deviated.

[0091] When the value of (O1O2-O1O2') exceeds the predetermined straight-line distance range, it is determined that point O1 and point O2 have deviated.

[0092] The parallelism deviation correction action command shall be executed according to the following steps:

[0093] When α>β and the value of (α-β) is not within the predetermined deviation angle range, the pallet robot 1 rotates clockwise by the deviation angle of (α-β);

[0094] When α < β and the value of (α - β) is not within the predetermined deviation angle range, the pallet robot 1 rotates counterclockwise by the deviation angle of (α - β).

[0095] The center point deviation correction action command is executed according to the following steps: the pallet robot 1 rotates at a preset angle δ, causing the pallet robot 1 to retreat to point E, with a retreat distance of O1E. Then, the pallet robot 1 is straightened, and then the pallet robot 1 moves forward to point O3, with a forward distance of EO3, so that the center point O1 at the front end of the walking arm 13 of the pallet robot 1 moves to O3. The obstacle avoidance radar 131 detects point O2 at point O1 and returns at a distance of O1O2, and the obstacle avoidance radar 131 detects point O2 at point O1 and returns at a distance of O2O3.

[0096] Given O1O2 and O2O3, according to the Pythagorean theorem (O1O3... 2 =O1O2 2 -O2O3 2 Calculate the distance between O1 and O3: O1O3 = √(O1O2) 2 -O2O3 2 );

[0097] Given the preset angle δ, the distance O1E can be calculated using cosδ=O1O3 / O1E: O1E=O1O3 / cosδ;

[0098] According to the Pythagorean theorem: EO3 2 =O1E 2 -O1O3 2 The distance to EO3 can be calculated as follows: EO3 = √(O1E 2 -O1O3 2 ).

[0099] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this invention are included within the scope of protection of this invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the scope of protection of this invention.

Claims

1. An automatic positioning method for pallet robots applied in smart warehouses, characterized in that... Includes the following steps: (1) The pallet robot walks to one side of the pallet and makes the front ends of the two outermost walking arms of the pallet robot correspond one-to-one with the front ends of the two outermost supporting feet of the pallet; The upstream control system pre-sets a predetermined deviation angle range and a predetermined straight-line distance range between the center points of the front ends of the two walking arms and the center points of the front ends of the corresponding support legs. The center points of the front ends of the two outermost walking arms of the pallet robot are respectively equipped with obstacle avoidance radar. The pallet robot scans the two endpoints and the center point of the front ends of the two outermost support legs of the pallet through the obstacle avoidance radar, and calculates and analyzes the angles between the two endpoints and the center point of the front ends of the support legs and the obstacle avoidance radar, thereby obtaining the real-time angles and real-time straight-line distances between the front ends of the two outermost walking arms of the pallet robot and the front ends of the two outermost support legs of the pallet. (2) First, the parallelism deviation analysis of the straight line where the front end of the two walking arms of the pallet robot is located and the straight line where the front end of the corresponding support foot is located is performed through the upstream control system to determine whether the front end of the walking arm and the front end of the support foot are parallel. The real-time angle is compared with the predetermined deviation angle range to determine the parallelism deviation between the front end of the walking arm and the front end of the corresponding supporting foot. (3) Then, the center point deviation analysis between the front center point of the two walking arms of the pallet robot and the front center point of the corresponding support foot is performed through the upstream control system to determine whether there is a deviation between the front center point of the two walking arms of the pallet robot and the front center point of the corresponding support foot. The real-time straight-line distance is compared with the predetermined straight-line distance range to determine the deviation between the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot. (4) If the front end of the walking arm is parallel to the front end of the supporting foot, and the center point of the front end of the walking arm is aligned with the center point of the front end of the corresponding supporting foot, then the pallet robot starts to perform the lifting action; if the front end of the walking arm is not parallel to the front end of the corresponding supporting foot, and / or the center point of the front end of the walking arm is deviated from the center point of the front end of the corresponding supporting foot, then the pallet robot executes the corresponding correction action command to correct the deviation of the pallet robot.

2. The automatic positioning method for pallet robots applied to smart warehouses as described in claim 1, characterized in that: In step (2), the steps for determining the parallelism deviation between the front end of the walking arm and the front end of the corresponding supporting foot are as follows: (2-1) When the real-time angle is within the predetermined deviation angle range, it can be determined that the front end of the walking arm and the front end of the supporting foot are parallel, that is, the parallelism between the front end of the walking arm and the front end of the supporting foot is not deviated; (2-2) When the real-time angle exceeds the predetermined deviation angle range, it can be determined that the front end of the walking arm and the front end of the supporting foot are not parallel, that is, the parallelism between the front end of the walking arm and the front end of the supporting foot is deviated. In step (3), the steps for determining the deviation between the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are as follows: (3-1) If the real-time straight distance is within the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are not deviated; (3-2) If the real-time straight distance exceeds the predetermined straight distance range, it can be determined that the center point of the front end of the walking arm and the center point of the front end of the corresponding support foot are deviated. If the conditions in steps (2-1) and (3-1) are met, then let the pallet robot start to perform the pallet lifting action; If one or both of the situations in steps (2-2) and (3-2) occur, the pallet robot will execute the corresponding correction action command to correct its deviation.

3. The automatic positioning method for pallet robots applied to smart warehouses as described in claim 2, characterized in that: In step (4), if the situation in step (2-2) occurs, the parallelism deviation angle of the pallet robot is obtained by calculation, and the parallelism deviation correction action command of the pallet robot is formed; if the situation in step (2-2) does not occur, the deviation between the center point of the front end of the walking arm and the center point of the front end of the corresponding supporting foot is re-evaluated. If the situation in step (3-2) occurs, the center point deviation distance of the pallet robot is obtained by calculation, and the center point deviation correction action command of the pallet robot is generated. Then, the parallelism deviation correction action command and / or center point deviation correction action command are sent to the pallet robot through the upstream control system, so that the pallet robot can perform the corresponding actions to adjust the parallelism deviation and / or center point deviation between the front end of the walking arm and the front end of the corresponding support foot.

4. The automatic positioning method for pallet robots applied in smart warehouses as described in claim 3, characterized in that: The process also includes step (5), which involves checking, after adjusting the deviation between the front end of one set of walking arms and the front end of the corresponding support foot, whether there is any parallelism deviation or center point deviation between the front end of the other set of walking arms and the front end of the corresponding support foot, following steps (2) to (4) above. (5-1) If the conditions of steps (2-1) and (3-1) are met, then let the pallet robot start to perform the pallet lifting action; (5-2) The upstream control system pre-sets a predetermined number of deviation corrections. If the conditions of steps (2-1) and (3-1) are not met, it is determined whether the number of real-time corrections exceeds the predetermined number of deviation corrections. If the number of real-time corrections does not exceed the predetermined number of deviation corrections, steps (2) to (4) above are executed. If the number of real-time corrections exceeds the predetermined number of deviation corrections, the pallet robot will issue an alarm.

5. The automatic positioning method for pallet robots applied to smart warehouses as described in any one of claims 1-4, characterized in that: In step (2), the parallelism deviation between the front end of the outermost walking arm and the front end of the corresponding outermost supporting foot is calculated using a parallelism judgment formula; the parallelism judgment formula is derived as follows: Assume the distance between the two endpoints A and B of the front end of the pallet's support leg is AB, and O2 is the center point of AB; The distance between the two endpoints C and D at the front end of the walking arm is CD, and O1 is the center point of CD; The distance returned by the obstacle avoidance radar after detecting point A is O1A; The distance returned by the obstacle avoidance radar after detecting point B is O1B; The angle returned by the obstacle avoidance radar from point B is ∠BO1O2, denoted as γ; Let the horizontal angle from AB to CD be ∠ABO1, denoted as α; and the horizontal angle from CD to AB be ∠DO1B, denoted as β. According to the Pythagorean theorem and the inverse cosine theorem: cosα = (AB) 2 +O1B 2 -O1A 2 ) / 2*AB*O1B, α=arccosα, and then calculate the angle of α; Calculate the angle of β: β = 90° - γ; Calculate the parallelism deviation value: α - β; When the value of (α-β) is within the predetermined deviation angle range, AB is determined to be parallel to CD; When the value of (α-β) is not within the predetermined deviation angle range, it is determined that AB and CD are not parallel.

6. The automatic positioning method for pallet robots applied in smart warehouses as described in claim 5, characterized in that: In step (3), the center point deviation between the outermost walking arm tip and the corresponding outermost support foot tip is calculated using the center point deviation judgment formula; the center point deviation judgment formula is derived as follows: The upstream control system pre-sets the predetermined straight-line distance between the front ends of the two walking arms and the front ends of the corresponding support feet as O1O2'; According to the Pythagorean theorem: O1O2 2 =O2B 2 +O1B 2 -2*O2B*O1B*cosα, calculate the distance between O1 and O2; When the value of (O1O2-O1O2') is within the predetermined straight-line distance range, it is determined that point O1 and point O2 are not deviated. When the value of (O1O2-O1O2') exceeds the predetermined straight-line distance range, it is determined that point O1 and point O2 have deviated.

7. The automatic positioning method for pallet robots applied to smart warehouses as described in claim 6, characterized in that: The parallelism deviation correction command is executed according to the following steps: When α>β and the value of (α-β) is not within the predetermined deviation angle range, the pallet robot rotates clockwise by the deviation angle of (α-β). When α < β and the value of (α - β) is not within the predetermined deviation angle range, the pallet robot rotates counterclockwise by the deviation angle of (α - β).

8. The automatic positioning method for pallet robots applied in smart warehouses as described in claim 7, characterized in that: The center point deviation correction action command is executed according to the following steps: the pallet robot rotates at a preset angle δ, causing the pallet robot to retreat to point E, with a retreat distance of O1E; then the pallet robot is straightened, and then the pallet robot moves forward to point O3, with a forward distance of EO3, so that the center point O1 at the front end of the pallet robot's walking arm moves to O3; the obstacle avoidance radar detects point O2 at point O1 and returns at a distance of O1O2, and the obstacle avoidance radar detects point O2 at point O1 and returns at a distance of O2O3. Given O1O2 and O2O3, according to the Pythagorean theorem (O1O3... 2 =O1O2 2 -O2O3 2 Calculate the distance between O1 and O3: O1O3 = √(O1O2) 2 -O2O3 2 ); Given the preset angle δ, the distance O1E can be calculated using cosδ=O1O3 / O1E: O1E=O1O3 / cosδ; According to the Pythagorean theorem: EO3 2 =O1E 2 -O1O3 2 The distance to EO3 can be calculated as follows: EO3 = √(O1E 2 -O1O3 2 ).

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