Method for determining alignment state, controller, and material handling equipment
A method for determining an alignment state includes: acquiring, by using a sensor, target images of a first stacking object and a second stacking object; acquiring, from the target images, a first target image region of the first stacking object and a second target image region of the second stacking object; and determining a pixel difference between the first target image region and the second target image region, and comparing the pixel difference with a threshold, to determine an alignment state between the first stacking object and the second stacking object. Embodiments of the present disclosure are used to implement alignment between a first stacking object and a second stacking object during stacking.
1 . A material handling equipment, comprising a controller, wherein the controller is configured to execute program instructions, to implement the following steps:
acquiring, by using a sensor, target images of a first stacking object and a second stacking object;
acquiring, from the target images, a first target image region of the first stacking object and a second target image region of the second stacking object; and
determining a pixel difference between the first target image region and the second target image region, and comparing the pixel difference with a threshold, to determine an alignment state between the first stacking object and the second stacking object,
wherein the controller is further configured to execute the following steps:
before determining the alignment state, controlling material handling equipment to move the first stacking object to a stacking preparation position, to complete a pre-alignment action relative to the second stacking object.
2 . The material handling equipment according to claim 1 , wherein the acquiring, by using the sensor, the target images of the first stacking object and the second stacking object comprises:
acquiring, by using the sensor, original images of the first stacking object and the second stacking object; and
performing, based on a pre-calibrated sensor intrinsic parameter, distortion correction on the original images, to acquire the target images.
3 . The material handling equipment according to claim 1 , wherein the determining the pixel difference between the first target image region and the second target image region comprises:
using a pixel relationship vector between a first center point in the first target image region and a second center line in the second target image region as the pixel difference.
4 . The material handling equipment according to claim 3 , wherein the pixel relationship vector is a vertical vector from the first center point to the second center line.
5 . The material handling equipment according to claim 4 , wherein the first stacking object is a first material cage, and the second stacking object is a second material cage; and
the first center point is a geometric center point or a central vertex of a first foot cup of the first material cage, and the second center line is a center line of a second upright of the second material cage.
6 . The material handling equipment according to claim 1 , wherein the determining the pixel difference between the first target image region and the second target image region comprises:
using a pixel relationship vector between a first center point in the first target image region and a second center point in the second target image region as the pixel difference.
7 . The material handling equipment according to claim 6 , wherein the pixel relationship vector is a connection vector from the first center point to the second center point.
8 . The material handling equipment according to claim 7 , wherein the first stacking object is a first material cage, and the second stacking object is a second material cage; and
the first center point is a geometric center point or a central vertex of a first foot cup of the first material cage, and the second center point is a geometric center point or a central vertex of a second upright of the second material cage.
9 . The material handling equipment according to claim 1 , wherein the determining the pixel difference between the first target image region and the second target image region comprises:
using a pixel relationship vector between a first center line in the first target image region and a fourth center point in the second target image region as the pixel difference.
10 . The material handling equipment according to claim 9 , wherein the pixel relationship vector is a vertical vector from the fourth center point to the first center line.
11 . The material handling equipment according to claim 10 , wherein the first stacking object is a first material cage, and the second stacking object is a second material cage; and
the first center line is a center line of a first foot cup of the first material cage, and the fourth center point is a geometric center point or a central vertex of a second upright of the second material cage.
12 . The material handling equipment according to claim 1 , wherein the comparing the pixel difference with the threshold, to determine the alignment state between the first stacking object and the second stacking object comprises:
in a case that the pixel difference is greater than or equal to a first threshold, determining that the alignment state is not aligned; or
in a case that the pixel difference is less than a first threshold, determining that the alignment state is aligned.
13 . The material handling equipment according to claim 12 , wherein the controller is further configured to execute the following steps:
in a case that the alignment state is not aligned, controlling, based on the pixel difference, material handling equipment to adjust a pose;
re-acquiring, by using the sensor, a target image of the first stacking object and a target image of the second stacking object;
re-determining a pixel difference between a first target image region and a second target image region; and
re-determining, based on the pixel difference, the alignment state until the pixel difference is less than the first threshold.
14 . The material handling equipment according to claim 13 , wherein the controlling, based on the pixel difference, the material handling equipment to adjust the pose comprises:
determining, based on the pixel difference, a control quantity using inverse kinematics; and
controlling, based on the control quantity, the material handling equipment to adjust the pose, the pose comprising a pose of a chassis or a pose of a fork.
15 . The material handling equipment according to claim 12 , wherein the controller is further configured to execute the following steps:
in a case that the alignment state is aligned, controlling material handling equipment to place the first stacking object onto the second stacking object, to complete stacking.
16 . The material handling equipment according to claim 1 , wherein the first stacking object is a first material cage, and the second stacking object is a second material cage;
the first target image region comprises at least a partial region of a first foot cup of the first material cage and at least a partial region of a third foot cup of the first material cage; and
the second target image region comprises at least a partial region of a second upright of the second material cage and at least a partial region of a fourth upright of the second material cage.
17 . The material handling equipment according to claim 16 , wherein the first target image region further comprises at least a partial region of a fifth foot cup of the first material cage and at least a partial region of a seventh foot cup of the first material cage; and
the second target image region further comprises at least a partial region of a sixth upright of the second material cage and at least a partial region of an eighth upright of the second material cage.
18 . A controller, wherein the controller is configured to execute program instructions, to implement the following steps:
acquiring, by using a sensor, target images of a first stacking object and a second stacking object;
acquiring, from the target images, a first target image region of the first stacking object and a second target image region of the second stacking object; and
determining a pixel difference between the first target image region and the second target image region, and comparing the pixel difference with a threshold, to determine an alignment state between the first stacking object and the second stacking object,
wherein the controller is further configured to execute the following steps:
before determining the alignment state, controlling material handling equipment to move the first stacking object to a stacking preparation position, to complete a pre-alignment action relative to the second stacking object.
19 . A method for determining an alignment state, comprising:
acquiring, by using a sensor, target images of a first stacking object and a second stacking object;
acquiring, from the target images, a first target image region of the first stacking object and a second target image region of the second stacking object; and
determining a pixel difference between the first target image region and the second target image region, and comparing the pixel difference with a threshold, to determine an alignment state between the first stacking object and the second stacking object,
wherein the method further comprises:
before determining the alignment state, controlling material handling equipment to move the first stacking object to a stacking preparation position, to complete a pre-alignment action relative to the second stacking object.