A method, storage medium and system for controlling the access of goods at the top of a forklift ramp

Abstract

The present invention discloses a method, storage medium and system for controlling the access of cargo at the top of a forklift ramp. The method comprises: obtaining the inclination angle of the vehicle body, the inclination angle of the cargo fork and the distance between the front end of the cargo fork and the ground in real time; raising / lowering the cargo fork in real time according to the change in the inclination angle of the vehicle body and the distance between the front end of the cargo fork and the ground, so that the distance between the front end of the cargo fork and the ground is always not less than a minimum height threshold; at the same time, adjusting the angle of the cargo fork in real time according to the inclination angle of the cargo fork, so that the cargo fork remains parallel to the horizontal ground; the present invention can adapt to ramps with different inclination angles by dynamically adjusting the height and angle of the cargo fork, thereby avoiding the situation where the cargo fork collides with the ramp during the process of going up and down the slope, and can meet the needs of the forklift for accessing cargo at the top of the ramp on the ramp.

Description

Technical Field

[0001] The present invention relates to the technical field of forklifts, and in particular to a method, storage medium and system for controlling access of cargo at the top of a forklift ramp. Background Art

[0002] A forklift is an industrial handling vehicle, which refers to various wheeled handling vehicles used for loading and unloading, stacking and short-distance transportation of palletized goods.

[0003] Chinese patent application CN110282580A discloses a fork tilt control system. This system determines the target fork angle based on the tilt angle, fork tilt, and vehicle body tilt, and then adjusts the fork angle to the target angle. This allows for accurate fork adjustment, preventing problems such as forks digging into cargo, vehicles, or pallets. However, this system is not suitable for situations where cargo is placed horizontally at the top of a ramp.

[0004] 1) For a ramp with a known slope, it can only allow a forklift to drive up the ramp, while the cargo itself is horizontal. The forklift or forklift AGV cannot smoothly pick up the cargo at the top of the ramp on the ramp.

[0005] 2) For ramps of unknown slope, the fork angle can no longer be adjusted according to the slope. As the fork approaches the ramp, the forklift will brake to avoid collision with the ramp, making it impossible to access the cargo at the top of the ramp. Summary of the Invention

[0006] To address the above issues, the inventors have provided a method, storage medium, and system for controlling the access of cargo at the top of a forklift ramp. During the uphill and downhill processes, the height and angle of the forks are adjusted in real time, thereby avoiding collisions between the forks and the ramp and enabling the access of cargo at the top of ramps with unknown slopes.

[0007] According to a first aspect, the present invention provides a method for accessing cargo at the top of a forklift ramp, comprising:

[0008] Step 1: Obtain the vehicle body inclination angle, fork inclination angle, and the distance between the fork front end and the ground in real time;

[0009] Step 2: Raise / lower the forks in real time based on the change in the vehicle body inclination angle and the distance between the forks and the ground, ensuring that the distance between the forks and the ground is always no less than the minimum height threshold;

[0010] At the same time, the angle of the fork is adjusted in real time according to the inclination of the fork to keep the fork parallel to the horizontal ground.

[0011] Furthermore, the step 2 includes:

[0012] Obtain the distance between the rear end of the fork and the ground in real time;

[0013] Fork enters ramp stage: When the distance between the rear end of the fork and the ground remains unchanged and the distance between the front end of the fork and the ground gradually decreases, the fork enters the ramp and is raised in real time according to the distance between the front end of the fork and the ground, so that the distance between the front end of the fork and the ground is always not less than the minimum height threshold;

[0014] The vehicle body partially enters the ramp stage: When the vehicle body inclination angle gradually increases and the vehicle body partially enters the ramp, the forks are raised in real time according to the change in the vehicle body inclination angle and the distance between the front end of the forks and the ground;

[0015] At the same time, the fork angle is adjusted in real time according to the fork inclination to keep the fork parallel to the horizontal ground;

[0016] The vehicle body has completely entered the ramp stage: When the vehicle body inclination angle no longer increases, the vehicle body has completely entered the ramp. At this time, the forks are raised in real time according to the distance between the front end of the forks and the ground, so that the distance between the front end of the forks and the ground is always not less than the minimum height threshold;

[0017] After storing or retrieving goods, the vehicle body gradually moves backwards. At this time, the forks are lowered in real time according to the distance between the front end of the forks and the ground, while ensuring that the distance between the front end of the forks and the ground is always not less than the minimum height threshold;

[0018] The vehicle body partially exits the ramp stage: When the vehicle body inclination angle gradually decreases and the vehicle body partially exits the ramp, the forks are lowered in real time according to the change in the vehicle body inclination angle and the distance between the front end of the forks and the ground;

[0019] At the same time, the fork angle is adjusted in real time according to the fork inclination to keep the fork parallel to the horizontal ground;

[0020] When the vehicle body completely exits the ramp: When the inclination angle of the vehicle body no longer decreases and the vehicle body completely exits the ramp, the forks are lowered in real time according to the distance between the front end of the forks and the ground, while ensuring that the distance between the front end of the forks and the ground is always not less than the minimum height threshold.

[0021] Furthermore, assuming that the amount of fork lift when the vehicle body enters the ramp or the amount of fork lowering when the vehicle body exits the ramp is δ, we have:

[0022] δ=L*sinΔβ

[0023] Where L is the length of the fork and Δβ is the change in the vehicle body inclination angle.

[0024] Furthermore, when the forklift / forklift AGV takes the cargo from the container, the method further includes:

[0025] When a forklift / forklift AGV is picking up cargo at the top of the ramp, it obtains the distance between the forks and the top of the container and the height of the cargo;

[0026] Determine the lifting height of the cargo by the fork according to the distance between the fork and the top of the container and the height of the cargo;

[0027] Control the fork lifting according to the lifting height.

[0028] According to a second aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program can be executed by a processor to implement the steps of the above method.

[0029] According to a third aspect, the present invention further provides a forklift ramp top cargo access control system, comprising:

[0030] Vehicle body inclination detector, used to detect vehicle body inclination;

[0031] Fork inclination detector, used to detect the inclination of the fork;

[0032] The first height detector is provided at the front end of the fork and is used to detect the distance between the front end of the fork and the ground;

[0033] The controller includes the computer-readable storage medium as described above, and is used to raise / lower the forks in real time based on the change in the vehicle body inclination angle and the distance between the front end of the forks and the ground, so that the distance between the front end of the forks and the ground is always not less than a minimum height threshold; and is also used to adjust the angle of the forks in real time based on the inclination angle of the forks, so that the forks remain parallel to the horizontal ground.

[0034] Furthermore, the system also includes:

[0035] The second height detector is located at the rear end of the fork and is used to detect the distance between the rear end of the fork and the ground;

[0036] The controller is further used to determine whether the fork enters the ramp according to the distance between the rear end of the fork and the ground and the distance between the front end of the fork and the ground.

[0037] Furthermore, the system also includes:

[0038] The top space detector is installed on the fork and is used to detect the distance between the fork and the top of the container when picking up goods;

[0039] The controller is also used to determine the lifting height of the cargo by the fork according to the distance between the fork and the top of the container and the height of the cargo, and control the lifting of the fork according to the lifting height.

[0040] Furthermore, the system also includes:

[0041] Fork stroke detector is used to detect whether the fork is raised / lowered in place.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) By adjusting the height and angle of the fork in real time, the storage and retrieval of goods at the top of a ramp with an unknown slope is achieved.

[0044] (2) It effectively avoids the problem of forklift forks colliding with the ramp when going up and down the slope.

[0045] (3) The automatic adjustment of the forklift when the forklift is passing over the cargo fork can be realized, which can adapt to ramps with different inclination angles and meet the needs of the forklift to store and retrieve cargo at the top of the ramp. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the structure of the forklift AGV in Example 1;

[0047] Figure 2 Schematic diagram of the forklift AGV control system in Example 1;

[0048] Figure 3 This is a schematic diagram of the forklift AGV picking up process in Example 1.

[0049] Reference numerals:

[0050] 1-controller; 21-AGV navigation sensor; 22-travel speed detector; 23-vehicle body inclination detector; 31-fork inclination detector; 32-first height detector; 33-second height detector; 34-fork travel detector; 35-top space detector; 36-cargo front obstacle detector. DETAILED DESCRIPTION

[0051] The present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings.

[0052] Example 1

[0053] like Figure 1-2 As shown, the present invention provides a forklift ramp top cargo access system, including: a controller 1, a body inclination detector 23, a fork inclination detector 31, a first height detector 32, a second height detector 33, a fork stroke detector 34, a top space detector 35 and a cargo front obstacle detector 36, wherein the forklift adopts a forklift AGV, which includes an AGV body and forks, and the forklift AGV is controlled by the AGV navigation sensor 21 and the walking speed detector 22.

[0054] The vehicle body inclination detector 23 is used to detect the inclination angle β of the vehicle body. The first height detector 32 is provided at the front end of the fork and is used to detect the distance H2 from the front end of the fork to the ground. The second height detector 33 is provided at the rear end of the fork and is used to detect the distance H1 from the rear end of the fork to the ground. The fork stroke detector 34 is used to detect whether the fork is in place. The top space detector 35 is used to detect the distance h between the fork and the top of the container when picking up the goods. The front obstacle detector 36 is used to detect the distance between the front end of the fork and the goods / obstacles in front, so as to prevent the fork from colliding with the goods / obstacles.

[0055] Specifically, if Figure 3 As shown in the figure, when the forklift AGV is picking up the goods in the container, the process is as follows:

[0056] Smooth ground driving stage: The forklift AGV is connected to the circuit and relies on the AGV navigation sensor 21 and the walking speed detector 22 to travel on the smooth ground. At this time, the body and the fork remain parallel to the smooth ground, H1 = H2, and the value can be set to the minimum height threshold y.

[0057] Fork enters the ramp stage: As the forklift AGV moves forward, the fork gradually enters the top of the ramp. At this time, H1 gradually decreases, while H2 remains unchanged. At this time, the system confirms that the AGV is about to go uphill, and the controller 1 controls the fork to rise vertically, always ensuring that H1 detected by the first height detector 32 is y.

[0058] The vehicle body enters the ramp stage: When the front wheels of the AGV enter the ramp, the vehicle body inclination angle β measured by the vehicle body inclination detector 23 gradually increases. The change in the vehicle body inclination angle will make it impossible for the fork to remain parallel to the horizontal ground. At this time, the controller 1 needs to adjust the inclination angle of the fork while controlling the fork to rise to keep it horizontal.

[0059] As the front wheel continues to move upward, the vehicle body inclination angle β gradually increases by a change of Δβ. The calculated fork lift distance δ = L * sin Δβ, where L is the fork length. During this process, the fork travel detector 34 detects the change in fork height and feeds the signal back to the controller 1, achieving closed-loop control.

[0060] The vehicle body completely enters the ramp stage: When the rear wheels of the AGV enter the ramp, the vehicle body inclination angle β measured by the vehicle body inclination angle detector 23 will remain constant. At this time, there is no need to adjust the angle of the fork, only its height needs to be adjusted, that is, H1 detected by the first height detector 32 is always guaranteed to be y.

[0061] As the AGV moves along the ramp to the container entrance, the forks gradually extend into the pallet's "chuan"-shaped slot. When the forks reach their maximum forward position, the overhead clearance detector 35 is triggered, detecting and recording the distance h between the forks and the container top. When the forks lift cargo, their lift height must be less than hH, where H is the cargo height, to prevent collision with the container top.

[0062] After picking up the goods, the AGV starts to travel downhill. When both the front and rear wheels are on the slope, the height of the fork remains unchanged and the inclination angle of the fork remains unchanged.

[0063] When the vehicle body partially exits the ramp: When the rear wheels of the AGV return to the horizontal ground, the vehicle body inclination angle β measured by the vehicle body inclination angle detector 23 gradually decreases, and the fork inclination angle detector 31 also changes. At this time, the inclination angle change is Δβ, and the calculated fork descent amount δ = L*sinΔβ. At the same time, the inclination angle of the fork needs to be adjusted to keep the fork parallel to the horizontal ground.

[0064] When the vehicle body fully exits the ramp, the vehicle's tilt angle no longer decreases and the vehicle fully exits the ramp. The forks are lowered in real time based on the distance H1 between the fork tip and the ground, ensuring H1 = y. When H1 no longer changes, the AGV resumes driving on a flat surface.

[0065] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A method for accessing cargo at the top of a forklift ramp, characterized in that: include: Step 1: Obtain the vehicle body inclination angle, fork inclination angle, and the distance between the fork front end and the ground in real time; Step 2: Raise / lower the forks in real time based on the change in the vehicle body inclination angle and the distance between the forks and the ground, ensuring that the distance between the forks and the ground is always no less than the minimum height threshold; At the same time, the fork angle is adjusted in real time according to the fork inclination to keep the fork parallel to the horizontal ground; The step 2 includes: Obtain the distance between the rear end of the fork and the ground in real time; Fork enters ramp stage: When the distance between the rear end of the fork and the ground remains unchanged and the distance between the front end of the fork and the ground gradually decreases, the fork enters the ramp and is raised in real time according to the distance between the front end of the fork and the ground, so that the distance between the front end of the fork and the ground is always not less than the minimum height threshold; The vehicle body partially enters the ramp stage: When the vehicle body inclination angle gradually increases and the vehicle body partially enters the ramp, the forks are raised in real time according to the change in the vehicle body inclination angle and the distance between the front end of the forks and the ground; At the same time, the fork angle is adjusted in real time according to the fork inclination to keep the fork parallel to the horizontal ground; The vehicle body has completely entered the ramp stage: When the vehicle body inclination angle no longer increases, the vehicle body has completely entered the ramp. At this time, the forks are raised in real time according to the distance between the front end of the forks and the ground, so that the distance between the front end of the forks and the ground is always not less than the minimum height threshold; After storing or retrieving goods, the vehicle body gradually moves backwards. At this time, the forks are lowered in real time according to the distance between the front end of the forks and the ground, while ensuring that the distance between the front end of the forks and the ground is always not less than the minimum height threshold; The vehicle body partially exits the ramp stage: When the vehicle body inclination angle gradually decreases and the vehicle body partially exits the ramp, the forks are lowered in real time according to the change in the vehicle body inclination angle and the distance between the front end of the forks and the ground; At the same time, the fork angle is adjusted in real time according to the fork inclination to keep the fork parallel to the horizontal ground; When the vehicle body completely exits the ramp: When the inclination angle of the vehicle body no longer decreases and the vehicle body completely exits the ramp, the forks are lowered in real time according to the distance between the front end of the forks and the ground, while ensuring that the distance between the front end of the forks and the ground is always not less than the minimum height threshold.

2. The method according to claim 1, wherein Assuming that the amount of fork rise when the vehicle body enters the ramp or the amount of fork fall when the vehicle body exits the ramp is δ, we have: δ=L*sinΔβ Where L is the length of the fork and Δβ is the change in the vehicle body inclination angle.

3. The method according to claim 1, wherein When the forklift / forklift AGV takes the cargo from the container, the method further includes: When a forklift / forklift AGV is picking up cargo at the top of the ramp, it obtains the distance between the forks and the top of the container and the height of the cargo; Determine the lifting height of the cargo by the fork according to the distance between the fork and the top of the container and the height of the cargo; Control the fork lifting according to the lifting height.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program can be executed by a processor to implement the steps of the method according to any one of claims 1 to 3.

5. A cargo access control system at the top of a forklift ramp, characterized in that: include: Vehicle body inclination detector, used to detect vehicle body inclination; Fork inclination detector, used to detect the inclination of the fork; The first height detector is provided at the front end of the fork and is used to detect the distance between the front end of the fork and the ground; The controller includes the computer-readable storage medium as described in claim 4, and is used to raise / lower the forks in real time based on the change in the inclination angle of the vehicle body and the distance between the front end of the forks and the ground, so that the distance between the front end of the forks and the ground is always not less than a minimum height threshold; and is further used to adjust the angle of the forks in real time based on the inclination angle of the forks to keep the forks parallel to the horizontal ground.

6. The system according to claim 5, wherein: Also includes: The second height detector is located at the rear end of the fork and is used to detect the distance between the rear end of the fork and the ground; The controller is further used to determine whether the fork enters the ramp according to the distance between the rear end of the fork and the ground and the distance between the front end of the fork and the ground.

7. The system according to claim 5, wherein: Also includes: The top space detector is installed on the fork and is used to detect the distance between the fork and the top of the container when picking up goods; The controller is also used to determine the lifting height of the cargo by the fork according to the distance between the fork and the top of the container and the height of the cargo, and control the lifting of the fork according to the lifting height.

8. The system according to claim 5, wherein: Also includes: Fork stroke detector is used to detect whether the fork is raised / lowered in place.

Images