Mobile robot with active safety motion protection

Abstract

The invention provides a mobile robot with active safety motion protection. The mobile robot comprises a mobile base; a robot arm; the plurality of laser radars are arranged at a plurality of corner ends of the mobile base and are used for collecting point cloud information around the mobile base; the control system is used for generating an occupied grid map in a monitoring range according to the point cloud information, the monitoring range is determined according to the working space of the mechanical arm, radar scanning points of the preset monitoring range are obtained, the grid where each radar scanning point is located is determined, when the grid where one scanning point is located is in a non-occupied state, the point is determined to be a dynamic point, and the point is determined to be a dynamic point; and a preset point cloud number threshold value is obtained, whether a moving object exists in the monitoring range or not is judged according to the number of the dynamic points and the point cloud number threshold value, and when the moving object exists, the nearest distance between the dynamic points and the mechanical arm is generated, and the mechanical arm is controlled to operate according to the nearest distance. Safe operation control over the mechanical arm can be achieved, and the situation that the mechanical arm hurts surrounding people during working is avoided.

Description

Technical Field

[0001] This invention relates to mobile robots, and more specifically, to a mobile robot with active safety protection for movement. Background Technology

[0002] Stacking is indispensable in industries such as retail, manufacturing, and logistics. It refers to arranging materials of different sizes and shapes on a pallet for storage, transportation, or distribution. The goal is to efficiently build a stable stack, maximizing pallet space utilization while ensuring the materials are not damaged. Manual stacking is slow and inefficient, and manually handling heavy boxes poses significant safety risks. Therefore, the demand for robotic stacking is increasing.

[0003] One of the main challenges of traditional robotic arm offline palletizing is the need for significant investment in infrastructure, particularly in sequencers, to ensure materials arrive in the correct order for palletizing operations. Mobile robot palletizing solutions, on the other hand, do not require a specific material arrival order and can perform stable, densely packed palletizing operations, making them more flexible and cost-effective than traditional palletizing robots.

[0004] Mobile robots can solve the problem of high robot installation costs and cope with the challenges of varying sorting line traffic. The number of mobile robots can be increased or decreased according to different business needs, and they can be customized and deployed at the end of various conveyor lines. However, how to ensure the safety of mobile robots is a problem that urgently needs to be solved. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide a mobile robot with active safety protection during movement.

[0006] The mobile robot with active safety motion protection provided by the present invention includes:

[0007] A movable base, used to move to any position or pause at any position and determine the orientation angle according to received control commands;

[0008] A robotic arm is used to grab and move a target box from the picking position to a placing position;

[0009] Multiple lidar sensors are disposed at multiple corners of the mobile base to collect point cloud information around the mobile base.

[0010] The control system is configured to acquire the point cloud information, acquire the dimensions of the mobile base, generate a polygonal warning frame around the mobile base based on the dimensions of the mobile base, detect whether there is a point cloud within the polygonal warning frame, and when the point cloud is detected, generate the distance between the point cloud within the warning frame and the mobile base, generate a speed adjustment ratio based on the distance between the point cloud within the warning frame and the mobile base, and control the mobile base to decelerate based on the speed adjustment ratio.

[0011] Preferably, the control system includes:

[0012] The point cloud acquisition module is used to acquire secure computing point cloud information. The secure computing point cloud information is collected by lidar, and multiple lidars are respectively set at multiple corners of the mobile base on the mobile robot.

[0013] The warning box generation module is used to obtain the dimensions of the mobile base and generate a polygonal warning box around the mobile base based on the dimensions of the mobile base;

[0014] The point cloud detection module is used to detect whether there is a point cloud within the polygonal warning frame, and to generate the distance between the point cloud within the warning frame and the mobile base when the point cloud is detected.

[0015] The speed adjustment module is used to generate a speed adjustment ratio based on the distance between the point cloud in the warning frame and the mobile base, and to control the mobile base to decelerate according to the speed adjustment ratio.

[0016] Preferably, the point cloud acquisition module includes the following units:

[0017] A radar control unit is used to control the lidar to collect point cloud information in order to obtain the point cloud information.

[0018] A point cloud processing unit is used to fit the point cloud information, determine the ground point cloud, and then remove the ground point cloud to generate target point cloud information.

[0019] The coordinate transformation unit is used to transform the target point cloud information into the robot coordinate system to generate the safety calculation point cloud information.

[0020] Preferably, the warning box generation module includes the following units:

[0021] The warning frame generation unit is used to obtain the dimensions of the mobile base and generate a warning frame around the mobile base according to the dimensions of the mobile base;

[0022] The trajectory prediction unit is used to acquire the warning time threshold and the running speed and running direction of the mobile robot, and to determine the predicted movement trajectory of the mobile robot based on the warning time threshold, running speed and running direction.

[0023] The warning box expansion unit is used to expand the warning box according to the predicted movement trajectory to generate the polygonal warning box.

[0024] Preferably, the point cloud detection module includes the following units:

[0025] A point cloud detection unit is used to perform point cloud detection on the polygonal warning frame to determine whether there is a point cloud within the polygonal warning frame.

[0026] The coordinate acquisition unit is used to acquire the coordinates of the point cloud in the robot coordinate system when the existence of point cloud is detected within the polygonal warning frame;

[0027] The distance calculation unit is used to obtain the position of the mobile base in the robot coordinate system and determine the nearest distance between the point cloud and the mobile base based on the position.

[0028] Preferably, the speed adjustment module includes the following units:

[0029] The deceleration acquisition unit is used to acquire the closest distance between the point cloud and the moving base and the previous deceleration ratio;

[0030] A motion prediction unit is used to obtain the moving speed of the mobile machine and calculate the predicted maximum moving distance of the mobile machine.

[0031] The ratio generation unit is used to generate a speed adjustment ratio based on the nearest distance, the previous deceleration ratio, and the predicted maximum movement distance, and to control the mobile base to decelerate according to the speed adjustment ratio.

[0032] Preferably, it also includes the following modules;

[0033] The escape control module is used to increase the speed adjustment ratio by a preset value when the existence of point cloud within the polygonal warning frame is not detected multiple times consecutively.

[0034] Preferably, the warning frame extension unit includes the following parts:

[0035] The warning box acquisition module is used to acquire multiple warning boxes generated based on the predicted movement trajectory.

[0036] The warning box combining module is used to combine multiple warning boxes to generate the polygonal warning box;

[0037] Warning box update module: As the mobile robot moves, the predicted movement trajectory is continuously updated, and the polygonal warning box is continuously updated accordingly.

[0038] Preferably, a plurality of the lidars are disposed at the four corners of the mobile base, and the top of each lidar faces the ground.

[0039] Preferably, the speed adjustment ratio is specifically the ratio of the closest distance between the point cloud and the moving base to the predicted farthest moving distance, multiplied by the previous deceleration ratio.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] In this invention, point cloud information of a pre-set monitoring range is initialized. An occupied grid map is generated within the monitoring range based on the point cloud information. The monitoring range is determined according to the working space of the robotic arm. Radar scan points of the pre-set monitoring range are acquired, and the grid where each radar scan point is located is determined. When a scan point's grid is in an unoccupied state, the point is determined to be a dynamic point. A pre-set point cloud quantity threshold is acquired. Based on the number of dynamic points and the point cloud quantity threshold, it is determined whether a moving object exists within the monitoring range. When a moving object exists, the closest distance between the dynamic point and the robotic arm is generated, and the robotic arm is controlled to operate based on this closest distance. This enables safe operation control of the robotic arm, preventing harm to surrounding personnel during operation. Furthermore, this invention continuously tracks the dynamic points until the distance between the dynamic point and the robotic arm exceeds a distance threshold, avoiding false alarms that the moving object has left the monitoring range when it enters the robotic arm's coverage area. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0043] Figure 1 This is a schematic diagram of the structure of a mobile robot with active safety motion protection in the first embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of a mobile robot with active safety motion protection in the first embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of a mobile robot with active safety motion protection in the second embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of a mobile robot with active safety motion protection in the third embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of a mobile robot with active safety motion protection in the fourth embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of a mobile robot with active safety motion protection in the fifth embodiment of the present invention;

[0049] Figure 7 This is a schematic diagram of a mobile robot with active safety motion protection in the sixth embodiment of the present invention;

[0050] Figure 8 This is a schematic diagram illustrating the safe movement of a mobile robot according to the sixth embodiment of the present invention. Detailed Implementation

[0051] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0052] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0053] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] Figure 1 This is a schematic diagram of the structure of a mobile robot with active safety motion protection in the first embodiment of the present invention. Figure 2 This is a schematic diagram of a mobile robot with active safety motion protection in the first embodiment of the present invention, as shown below. Figure 1 , Figure 2 As shown, the mobile robot with active safety motion protection provided by the present invention includes:

[0056] A movable base, used to move to any position or pause at any position and determine the orientation angle according to received control commands;

[0057] A robotic arm is used to grab and move a target box from the picking position to a placing position;

[0058] Multiple lidar sensors are disposed at multiple corners of the mobile base to collect point cloud information around the mobile base.

[0059] The control system is used to initialize point cloud information of a preset monitoring range, generate an occupied grid map of the monitoring range based on the point cloud information, wherein the monitoring range is determined according to the workspace of the robotic arm, acquire radar scan points of the preset monitoring range, and determine the grid where each radar scan point is located. When the grid where a scan point is located is in an unoccupied state, the point is determined to be a dynamic point. A preset point cloud quantity threshold is acquired, and the presence of a moving object in the monitoring range is determined based on the number of dynamic points and the point cloud quantity threshold. When the moving object is present, the nearest distance between the dynamic point and the robotic arm is generated, and the robotic arm is controlled to run based on the nearest distance.

[0060] In this embodiment of the invention, multiple lidar sensors are disposed at the four corners of the mobile base, with the top of each lidar sensor facing the ground. The point cloud information is collected by the lidar sensors; the robotic arm is disposed at the front end of the mobile base.

[0061] In this embodiment of the invention, the monitoring range is a rectangular warning frame surrounding the robotic arm, and the extension range of the robotic arm is located within the warning frame.

[0062] During initialization, the robotic arm's coverage area is assumed to be empty.

[0063] Figure 3 This is a schematic diagram of a mobile robot with active safety motion protection in the second embodiment of the present invention, as shown below. Figure 3 As shown, the control system includes:

[0064] The grid map generation module is used to initialize the point cloud information of the preset monitoring range, and generate an occupied grid map in the monitoring range based on the point cloud information. The monitoring range is determined according to the working space of the robotic arm.

[0065] The dynamic point determination module is used to acquire radar scanning points within a preset monitoring range and determine the grid where each radar scanning point is located. When the grid where a scanning point is located is in an unoccupied state, the point is determined to be a dynamic point.

[0066] The moving object detection module is used to obtain a preset point cloud quantity threshold and determine whether there is a moving object in the monitoring range based on the number of dynamic points and the point cloud quantity threshold.

[0067] The robotic arm control module is used to generate the closest distance between the dynamic point and the robotic arm when the moving object is present, and to control the operation of the robotic arm based on the closest distance.

[0068] Figure 4 This is a schematic diagram of a mobile robot with active safety motion protection in the third embodiment of the present invention, as shown below. Figure 4 As shown, the raster map generation module includes the following units:

[0069] A point cloud information acquisition unit is used to control the lidar to collect point cloud information from the monitoring range in order to obtain the point cloud information.

[0070] A grid generation unit is used to generate an occupied grid map within the monitoring range based on the point cloud information. The occupied grid map is used to represent the occupied status of the monitoring range.

[0071] The grid occupancy determination unit is used to acquire the occupied grid map and determine the occupancy status of each grid on the occupied grid map.

[0072] In this embodiment of the invention, in the initial state, when a grid cell on the grid map is occupied, it is marked as occupied, and when a grid cell on the grid map is not occupied, it is marked as idle.

[0073] In a variation of the present invention, the raster map generation module includes the following units:

[0074] A point cloud information acquisition unit is used to control the lidar to collect point cloud information within the monitoring range in order to obtain the point cloud information.

[0075] The stability monitoring unit is used to monitor the stability of the point cloud information within a preset time threshold. When some points in the point cloud information have positional changes, the unit returns to the point cloud information acquisition unit; otherwise, the unit triggers the raster generation unit.

[0076] A grid generation unit is used to generate an occupied grid map within the monitoring range based on the point cloud information. The occupied grid map is used to represent the occupied status of the monitoring range.

[0077] The grid occupancy determination module is used to acquire the occupied grid map and determine the occupancy status of each grid on the occupied grid map.

[0078] In this embodiment of the invention, when some points in the point cloud information have positional changes, such as changes within 1 second, it indicates that there is a moving object, such as a person, within the monitoring range. In this case, it is necessary to re-initialize to avoid treating the moving object as an environmental point cloud.

[0079] Figure 5 This is a schematic diagram of a mobile robot with active safety motion protection in the fourth embodiment of the present invention, as shown below. Figure 5 As shown, the dynamic point determination module includes the following units:

[0080] A grid determination unit is used to acquire radar scan points within a preset monitoring range and determine the grid where each radar scan point is located.

[0081] The dynamic point determination unit is used to determine the occupancy status of the grid corresponding to each scan point. When the grid where a scan point is located is in an unoccupied state, the point is determined to be a dynamic point.

[0082] A quantity determination unit is used to obtain the position of each of the dynamic points and determine the quantity of the dynamic points.

[0083] In this embodiment of the invention, when acquiring the radar scan points of the monitoring range again after initialization,

[0084] Figure 6 This is a schematic diagram of a mobile robot with active safety motion protection in the sixth embodiment of the present invention, as shown below. Figure 6 As shown, the moving object detection module includes the following units:

[0085] A denoising unit is used to denoise the dynamic points and determine the number of denoised dynamic points.

[0086] The point cloud comparison unit is used to obtain a preset point cloud quantity threshold and compare it with the number of denoised dynamic points and the point cloud quantity threshold.

[0087] The moving object determination unit is used to determine the existence of a moving object when the number of denoised dynamic points is greater than the point cloud number threshold.

[0088] In this embodiment of the invention, the dynamic point denoising is performed by comparing the retained points with the point cloud quantity threshold to determine whether there is a moving object.

[0089] The point cloud quantity threshold can be set to any value between 4 and 15.

[0090] Figure 7 This is a schematic diagram of a mobile robot with active safety motion protection in the sixth embodiment of the present invention, as shown below. Figure 7 As shown, the robotic arm control module includes the following units:

[0091] The dynamic point finding unit is used to find the dynamic point closest to the robotic arm when the moving object is present.

[0092] The nearest object confirmation unit is used to determine the closest distance between the moving object and the robotic arm based on the distance between the dynamic point closest to the robotic arm and the robotic arm;

[0093] The robotic arm control unit is used to acquire a preset distance threshold and control the robotic arm to decelerate, stop working, or work normally based on the relationship between the distance threshold and the nearest distance.

[0094] In this embodiment of the invention, when the nearest distance is greater than the distance threshold, the robotic arm is controlled to work normally; when the nearest distance is less than the distance threshold, the robotic arm is controlled to decelerate; when the nearest distance is less than the distance threshold and the dynamic point is close to the robotic arm, the robotic arm is controlled to stop working, such as when the distance between the nearest dynamic point and the robotic arm is less than 20 centimeters. The distance threshold can be set to any value between 1 meter and 2 meters.

[0095] Figure 8 This is a schematic diagram of a mobile robot with active safety motion protection in the sixth embodiment of the present invention, as shown below. Figure 8 As shown, the mobile robot with active safety motion protection provided by the present invention also includes a dynamic point tracking module;

[0096] The dynamic point tracking module is used to continuously track the dynamic point until the distance between the dynamic point and the robotic arm is greater than a distance threshold.

[0097] In this embodiment of the invention, when a moving object enters the coverage area of ​​the robotic arm, the moving object is continuously tracked until it disappears, and then the point cloud is initialized.

[0098] In this embodiment of the invention, point cloud information of a pre-set monitoring range is initialized. An occupied grid map is generated within the monitoring range based on the point cloud information. The monitoring range is determined according to the working space of the robotic arm. Radar scan points of the pre-set monitoring range are acquired, and the grid where each radar scan point is located is determined. When a scan point's grid is in an unoccupied state, the point is determined to be a dynamic point. A pre-set point cloud quantity threshold is acquired. Based on the number of dynamic points and the point cloud quantity threshold, it is determined whether a moving object exists within the monitoring range. When a moving object exists, the closest distance between the dynamic point and the robotic arm is generated, and the robotic arm is controlled to operate based on the closest distance. This enables safe operation control of the robotic arm, preventing injury to surrounding personnel during operation. In this invention, the dynamic point is continuously tracked until the distance between the dynamic point and the robotic arm is greater than a distance threshold, avoiding false alarms of a moving object leaving the monitoring range when it enters the robotic arm's coverage area.

[0099] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0100] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A mobile robot with active safety motion protection, characterized in that, The application relates to a mobile base, a mechanical arm, a plurality of laser radars and a control system. The mobile base is used for moving to any position or pausing at any position and determining a direction angle according to received control instructions. The mechanical arm is arranged on the mobile base and is used for picking up a target box on a taking position and moving and placing the target box on a placing position. The plurality of laser radars are arranged at a plurality of corner ends of the mobile base and are used for collecting point cloud information around the mobile base. The control system is used for initializing point cloud information of a preset monitoring range, generating an occupancy grid map in the monitoring range according to the point cloud information, determining the monitoring range according to a working space of the mechanical arm, obtaining radar scanning points of the preset monitoring range, determining a grid where each radar scanning point is located, determining a dynamic point when a grid where a scanning point is located is in a non-occupancy state, obtaining a preset point cloud quantity threshold, judging whether a moving object exists in the monitoring range according to the quantity of the dynamic points and the point cloud quantity threshold, and generating a nearest distance between the dynamic points and the mechanical arm and controlling the mechanical arm to operate according to the nearest distance when the moving object exists.

2. The mobile robot with active safety motion guard of claim 1, wherein, The control system comprises: a grid map generation module used for initializing point cloud information of a preset monitoring range, generating an occupancy grid map in the monitoring range according to the point cloud information, and determining the monitoring range according to a working space of the mechanical arm; a dynamic point determination module used for obtaining radar scanning points of the preset monitoring range and determining a grid where each radar scanning point is located; a moving object judgment module used for obtaining a preset point cloud quantity threshold, judging whether a moving object exists in the monitoring range according to the quantity of the dynamic points and the point cloud quantity threshold; a mechanical arm control module used for generating a nearest distance between the dynamic points and the mechanical arm and controlling the mechanical arm to operate according to the nearest distance when the moving object exists.

3. The mobile robot with active safety motion guard of claim 2, wherein, The grid map generation module comprises the following units: a point cloud information acquisition unit used for controlling the laser radars to collect point cloud information of the monitoring range to obtain the point cloud information; a grid generation unit used for generating an occupancy grid map in the monitoring range according to the point cloud information, wherein the occupancy grid map is used for indicating an occupancy state of the monitoring range; a grid occupancy determination unit used for obtaining the occupancy grid map and determining an occupancy state of each grid on the occupancy grid map.

4. The mobile robot with active safety motion guard of claim 2, wherein, The dynamic point determination module comprises the following units: a grid determination unit used for obtaining radar scanning points of the preset monitoring range and determining a grid where each radar scanning point is located; a dynamic point determination unit used for judging an occupancy state of a grid corresponding to each scanning point, and determining a dynamic point when a grid where a scanning point is located is in a non-occupancy state; a quantity determination unit used for obtaining a position of each dynamic point and determining the quantity of the dynamic points.

5. The mobile robot with active safety motion guard of claim 1, wherein, The moving object judgment module comprises the following units: a denoising unit used for denoising the dynamic points and determining the quantity of the denoised dynamic points. The point cloud comparison unit is configured to obtain a preset point cloud quantity threshold, and compare the quantity of the denoised dynamic points with the point cloud quantity threshold. The moving object determination unit is configured to determine that there is a moving object when the quantity of the denoised dynamic points is greater than the point cloud quantity threshold.

6. The mobile robot with active safety motion guard of claim 1, wherein, The mechanical arm control module comprises the following units: The dynamic point searching unit is configured to search for a dynamic point closest to the mechanical arm from the dynamic points when there is a moving object. The closest object confirming unit is configured to determine the closest distance between the moving object and the mechanical arm according to the distance between the dynamic point closest to the mechanical arm and the mechanical arm. The mechanical arm control unit is configured to obtain a preset distance threshold, and control the mechanical arm to decelerate, stop working or normally work according to the relationship between the distance threshold and the closest distance.

7. The mobile robot with active safety motion guard of claim 2, wherein, The dynamic point tracking module is further included. The dynamic point tracking module is configured to continuously track the dynamic point until the distance between the dynamic point and the mechanical arm is greater than the distance threshold.

8. The mobile robot with active safety motion guard of claim 4, wherein, The grid map generation module comprises the following units: The point cloud information obtaining unit is configured to control the laser radar to collect point cloud information of a monitoring range to obtain the point cloud information. The stability monitoring unit is configured to monitor the stability of the point cloud information within a preset time threshold, return to the point cloud information obtaining unit when there is a position change of part of the points in the point cloud information, or trigger the grid generation unit otherwise. The grid generation unit is configured to generate an occupancy grid map in the monitoring range according to the point cloud information, and the occupancy grid map is used to represent the occupancy state of the monitoring range. The grid occupancy determination module is configured to obtain the occupancy grid map and determine the occupancy state of each grid on the occupancy grid map.

9. The mobile robot with active safety motion guard of claim 1, wherein, A plurality of laser radars are arranged at four corner ends of the mobile base, and the top end of each laser radar faces the ground direction.

10. The mobile robot with active safety motion guard of claim 1, wherein, The monitoring range is a warning frame surrounding the mechanical arm, and the stretching range of the mechanical arm is located in the warning frame.

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