Robot position control method and system based on dynamic security domain

Abstract

The invention discloses a robot position control method and system based on a dynamic safety domain. The method at least comprises the following steps that the safety domain of a robot is initialized; robot position information is obtained; generating a motion track according to the position information, and if the motion track is safe, executing the motion track by the robot; updating the safety domain of the robot, and repeatedly executing the steps from acquiring the position information of the robot to updating the safety domain of the robot until the operation is finished; the system implemented based on the method at least comprises a sensing module, a planning module, a safety module and an execution module. By the adoption of the technical scheme, safety control over robot motion can be achieved, the method is suitable for various application scenes where the robot needs to move safely in the complex environment, meanwhile, the robot safety domain can be dynamically updated under the condition that the operation environment dynamically changes along with the operation process, and the safety of the robot is improved. Therefore, the robot is controlled not to collide with the obstacle, and the movement safety of the robot is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of robot control, and particularly to a robot position control method and system based on a dynamic safety domain. Background Art

[0002] With the continuous development of robot technology, robots have been widely used in industrial production lines, warehouse management and other fields. In these application scenarios, robots need to avoid collisions with the surrounding environment or other objects while completing tasks, and the establishment of a safety domain is a prerequisite for obstacle avoidance. Existing robot position control methods usually establish a static movable space according to the working environment as the safety domain in the entire operation process. However, during the operation process, the working environment of the robot may change. For example, the number of stacked materials continuously increases during the operation. At this time, the original static safety domain may become invalid or no longer applicable, so it is necessary to dynamically adjust the movable space according to the operation process. Summary of the Invention

[0003] The purpose of the present invention is to provide a robot position control method and system based on a dynamic safety domain to solve the problems raised in the above background art.

[0004] To solve the above technical problems, the present invention provides the following technical solutions: A robot position control system based on a dynamic safety domain includes the following functional modules: a sensing module, a planning module, a safety module, and a control module;

[0005] Preferably, the sensing module is used to obtain the robot position information in real time; the planning module is used to determine the movement trajectory of the robot according to the robot position information obtained in real time; the safety module is used to maintain the dynamic safety domain during the robot operation process; the control module is used to control the robot to complete the operation according to the operation process and the planned movement trajectory.

[0006] A robot position control system based on a dynamic safety domain executes the following process steps:

[0007] Step S301: Import a 3D model and generate a collision boundary; the collision boundary is a set of spatial surfaces used to describe the critical state of collision between the robot and an object, and is stored in the model library of the system;

[0008] Step S302: Construct an initial safety domain and a safety domain update rule;

[0009] Step S303: Control the robot position to complete the operation.

[0010] Preferably, the safety domain at least includes a safety space, a safety boundary, and variability. The safety space is a spatial body representing the scope of action of the safety domain. The safety domain becomes effective only when the robot is within this scope and does not change after initialization. The safety boundary is a set of spatial surfaces that describe the critical condition where the robot does not collide with the working environment, taking the union of the collision boundaries of all objects in the safety space. The variability takes values of static or dynamic, describing whether the safety boundary will change during the operation process.

[0011] Preferably, the safety domain update rule at least includes beat, safety domain, model, offset, method, and timing. Among them, the beat is the index of the robot position control step in the operation process, the safety domain is the index of the safety domain that changes, the model is the model index of the object that changes in the system model library, the offset is the pose offset of the object that changes in the safety space, the method is the way the object changes, at least including addition and deletion, and the timing is the relative relationship between the timing of the object change and the position control step, including before the start and after the completion.

[0012] A robot position control system based on a dynamic safety domain. The system controls the robot position to complete the operation, specifically including: the control module sends a beat signal to the safety module, the safety module updates all dynamic safety domains, the sensing module obtains the current position, the planning module plans a motion trajectory based on the current position and the target position, and the control module controls the robot position according to the motion trajectory.

[0013] Preferably, the target position includes the points directly recorded by the control module and also includes the real-time sensing results of the sensing module using the vision sensor. When planning, the planning module includes directly using the safety domain to plan a collision-free motion trajectory and also includes planning only based on the current position and the target position. The safety module determines whether a collision occurs according to the trajectory and the current safety domain.

[0014] A robot position control method based on a dynamic safety domain includes the following steps:

[0015] Step S501: Initialize the robot safety domain;

[0016] Step S502: Obtain the robot position information;

[0017] Step S503: Generate a motion trajectory according to the position information. If the motion trajectory is safe, the robot executes the motion trajectory;

[0018] Step S504: Update the robot safety domain and repeat steps S502 to S504 until the operation ends.

[0019] Preferably, the generation of the motion trajectory at least includes: traversing the safety domain, judging all safety domains required for motion trajectory planning according to the safety space of the safety domain; and generating an optimal path from the current position to the target position without crossing the safety boundary of the safety domain.

[0020] Preferably, the update of the robot safety domain at least includes: traversing the safety domain update rules, and updating the corresponding dynamic safety domain according to the update rules after the current position control beat is completed and before the next position control beat starts; the safety space update at least includes the steps of: calculating the model collision boundary according to the model index of the update rule and the offset of the model in the safety space; and updating the safety boundary of the safety domain according to the change mode of the update rule.

[0021] Preferably, the change mode at least includes two operations: addition and deletion. The addition operation merges all the outer faces of the safety boundary and the model collision boundary, and removes all the faces in the internal overlapping area, at least including: merging the spatial face sets of the safety boundary and the model collision boundary; removing the occluded internal faces through an intersection algorithm; and retaining the outer surface as the new safety boundary. The deletion operation: cuts off the part of the safety boundary that overlaps with the model collision boundary to generate a new boundary, at least including: cutting the faces of the safety boundary with the faces of the model collision boundary; retaining the faces of the safety boundary that are outside the model collision boundary; and adding the intersection faces of the model collision boundary and the safety boundary to close the cut.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By initializing the robot safety domain, obtaining the robot position information, generating a motion trajectory according to the position information, and only when the motion trajectory is safe, the robot executes the motion trajectory. At the same time, the robot safety domain is updated, and the steps of obtaining the robot position information to updating the robot safety domain are repeatedly executed until the operation ends. By adopting the technical solution of the present invention, the safe control of the robot motion can be realized, which is not only applicable to various application scenarios where the robot needs to move safely in a complex environment, but also can dynamically update the robot safety domain when the operation environment changes dynamically with the operation process, ensuring that the robot does not collide with obstacles and improving the safety of the robot motion. Description of the Drawings

[0023] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention.

[0024] In the drawings:

[0025] Figure 1 It is a schematic diagram of the architecture of a robot position control system based on a dynamic safety domain provided by an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the application of a robot position control system based on a dynamic safety domain provided by an embodiment of the present invention;

[0027] Figure 3 Execution flowchart of a robot position control system based on a dynamic safety domain provided by an embodiment of the present invention;

[0028] Figure 4 Schematic diagram of the robot packing operation process provided by an embodiment of the present invention;

[0029] Figure 5 Schematic flowchart of a method for controlling the position of a robot based on a dynamic safety domain provided by an embodiment of the present invention. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] In this embodiment, in combination with Figure 1 as shown, the present invention provides the following technical solution: A robot position control system based on a dynamic safety domain includes the following functional modules:

[0032] A sensing module 101, configured to obtain real-time robot position information;

[0033] A planning module 102, configured to determine the motion trajectory of the robot according to the real-time obtained robot position information;

[0034] A safety module 103, configured to maintain the dynamic safety domain during the robot operation process;

[0035] A control module 104, configured to control the robot to complete the operation according to the operation process and the planned motion trajectory.

[0036] Exemplarily, in combination with Figure 2As shown in the figure, taking a robot position control system for material boxing as an example, the overall working environment can be divided into an empty box area, a boxing area, and a material incoming area. There are L layers of empty boxes, and each box has R×C compartments. The robot needs to first grab an empty box from the idle area and place it in the boxing area, then grab materials from the material incoming area and sequentially place them in the compartments of the boxing area. After completing the boxing of one layer, it grabs an empty box from the next layer and repeats the process until all materials are boxed; during this process, the working environments of the empty box area and the boxing area are changing. The position control system needs to consider the structure of the boxes and the positions of each layer, and dynamically update the robot's operation safety domain according to the operation process to ensure that the robot can stack the boxes at the specified position without collision and place the materials in the specified grids.

[0037] In this embodiment, in combination with Figure 3 , the figure shows an execution flowchart of a robot position control system based on a dynamic safety domain provided by an embodiment of the present invention, including the following steps:

[0038] Step S301: Import a 3D model and generate a collision boundary: The collision boundary is a set of spatial surfaces used to describe the critical situation where the robot collides with an object, and is stored in the model library of the system.

[0039] In this embodiment, a material model M1, a compartment model M2, and a box model M3 are imported respectively. For simplicity, the collision boundaries of the material, the compartment, and the box are all described as the six surfaces of a cuboid.

[0040] Step S302: Construct an initial safety domain and safety domain update rules;

[0041] In this embodiment, the safety domain at least includes a safety space, a safety boundary, and variability. The safety space is a spatial body representing the scope of action of the safety domain. Only when the robot is within this scope does the safety domain take effect, and it does not change after initialization; the safety boundary is a set of spatial surfaces describing the critical situation where the robot does not collide with the working environment, and is the union of the collision boundaries of all objects in the safety space; the variability takes a value of static or dynamic, describing whether the safety boundary will change during the operation process.

[0042] Exemplarily, the following three safety domains can be set according to the robot's boxing work process:

[0043] Empty box safety domain F1: Describes the movable space of the robot in the empty box area. The safety space is set as a cuboid surrounding the empty box area, the safety boundary is set as the union of the collision boundaries of the ceiling, the ground, and the L layers of boxes, and the variability is set as dynamic;

[0044] Packing safety domain F2: Describes the movable space of the robot in the packing area. The safety space is set as a cuboid surrounding the packing area, the safety boundary is set as the union of the collision boundaries of the ceiling and the floor, and the variability is set as dynamic;

[0045] Incoming material safety domain F3: Describes the movable space of the robot in the incoming material area. The safety space is set as a cuboid surrounding the incoming material area, the safety boundary is set as the union of the collision boundaries of the ceiling, the floor and the incoming material device, and the variability is set as static.

[0046] Exemplarily, the safety domain update rules at least include rhythm, safety domain, model, offset, mode, and timing. Among them, the rhythm is the index of the robot position control step in the operation process, the safety domain is the index of the safety domain that changes, the model is the model index of the object that changes in the system model library, the offset is the pose offset of the object that changes in the safety space, the mode is the way the object changes, at least including addition and deletion, and the timing is the relative relationship between the timing of the object change and the position control step, including before start and after completion.

[0047] In this embodiment, the robot operation process is as Figure 4 shown, mainly including the following position control rhythms: B1 grabs the box on the (L - l + 1)-th layer from the empty box area, B2 places the box as the l-th layer in the packing area, B3 grabs the material from the incoming material area, and B4 places the material in the (r, c)-th grid of the l-th layer. Here, l, r, and c represent the target layer number, row number, and column number of the current operation. According to this process, the update rules are constructed as shown in Table 1 below. Each row of data represents a safety domain update rule:

[0048] Table 1

[0049]

[0050]

[0051] Among them, h 3 , l 2 and w 2 are respectively the height of the box model M3 and the length and width of the box grid model M2. For simplicity, only the Z coordinate part of the offset of Rule 1 and Rule 2 is shown, and the XYZ three coordinate parts of the offset of Rule 3 and Rule 4 are shown. There is no pose offset in this case.

[0052] Step S303: Control the robot position to complete the operation.

[0053] In a specific embodiment, the control module 104 sends a beat signal to the safety module 103. The safety module 103 updates all dynamic safety domains. The sensing module 101 obtains the current position. The planning module 102 plans a motion trajectory based on the current position and the target position. The control module 104 controls the position of the robot according to the motion trajectory.

[0054] Exemplarily, the target position can directly come from the points recorded by the control module 104, or can be the real-time sensing result of the sensing module 101 using a vision sensor or the like. When planning, the planning module 102 can directly use the safety domain to plan a collision-free motion trajectory, or can only plan according to the current position and the target position, and then the safety module 103 determines whether a collision occurs according to the trajectory and the current safety domain.

[0055] Based on the above embodiments, a robot position control method provided in the following embodiments can be applied to any of the above system embodiments.

[0056] In this embodiment, in combination with Figure 5 , the figure shows a schematic flowchart of a robot position control method based on a dynamic safety domain provided by an embodiment of the present invention, including the following steps:

[0057] Step S501: Initialize the robot safety domain;

[0058] In this embodiment, all the safety domains of the robot are reset to the initial safety domain.

[0059] Step S502: Obtain the robot position information;

[0060] In this embodiment, the robot position information includes the robot's current position information and target position information.

[0061] Step S503: Generate a motion trajectory according to the position information. If the motion trajectory is safe, the robot executes the motion trajectory;

[0062] In this embodiment, generating a motion trajectory at least includes: traversing the safety domain, and judging all the safety domains required for motion trajectory planning according to the safe space of the safety domain;

[0063] Exemplarily, beat B1 involves safety domain F1, beat B2 involves safety domains F1 and F2, beat B3 involves safety domains F2 and F3, beat B4 involves safety domain F2; on the premise of not crossing the safety boundary of the safety domain, generate an optimal path from the current position to the target position.

[0064] Step S504: Update the robot safety domain, and repeat steps S502 to S504 until the operation ends;

[0065] In this embodiment, updating the robot safety domain at least includes the steps of: traversing the safety domain update rules, and updating the corresponding dynamic safety domain according to the update rules between the completion of the control beat at the current position and the start of the control beat at the next position;

[0066] Exemplarily, updating the safety space at least includes the steps of: calculating the model collision boundary according to the model index of the update rule and the offset of the model in the safety space; updating the safety boundary of the safety domain according to the change mode of the update rule;

[0067] Exemplarily, the change mode at least includes two operations: adding and deleting. Among them, the adding operation combines all the outer faces of the safety boundary and the model collision boundary; removing all the faces in the internal overlapping area at least includes: combining the spatial face sets of the safety boundary and the model collision boundary; removing the occluded internal faces through an intersection algorithm; retaining the outer surface as the new safety boundary;

[0068] The deleting operation cuts off the part of the safety boundary that overlaps with the model collision boundary to generate a new boundary, which at least includes: cutting the faces of the safety boundary with the faces of the model collision boundary; retaining the faces of the safety boundary that are outside the model collision boundary; adding the intersection faces of the model collision boundary and the safety boundary to close the cut.

[0069] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0070] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A robot position control system based on dynamic safety domain, characterized in that: It includes the following functional modules: a perception module, a planning module, a safety module, and a control module; the perception module is used to obtain the robot's position information in real time; the planning module is used to determine the robot's motion trajectory based on the robot's position information obtained in real time; the safety module is used to maintain the dynamic safety domain of the robot's operation process; the control module is used to control the robot to complete the operation according to the operation process and the planned motion trajectory.

2. A robot position control system based on dynamic safety domain according to claim 1, characterized in that: The process steps performed by the system include: Step S301: importing a 3D model and generating a collision boundary; the collision boundary is a collection of spatial surfaces, used to describe the critical point where the robot collides with the object, and is stored in the model library of the system; Step S302: constructing an initial security domain and security domain update rules; Step S303: Control the robot position to complete the task.

3. A robot position control system based on dynamic safety domain according to claim 2, characterized in that: The safety domain at least includes a safety space, a safety boundary and variability. The safety space is a spatial body, which represents the scope of the safety domain. The safety domain takes effect only when the robot is within the scope and will not change after initialization. The safety boundary is a collection of spatial surfaces, which describes the critical point where the robot does not collide with the working environment, and is the union of the collision boundaries of all objects in the safety space. The variability can be static or dynamic, which describes whether the safety boundary will change during the operation.

4. The robot position control system based on dynamic safety domain according to claim 3, characterized in that: The safety domain update rule includes at least beat, safety domain, model, offset, method and timing, wherein the beat is the index of the robot position control step in the work process, the safety domain is the index of the safety domain that has changed, the model is the model index of the changed object in the system model library, the offset is the posture offset of the changed object in the safety space, the method is the method in which the object changes, including at least addition and deletion, and the timing is the relative relationship between the timing of the object change and the position control step, including before the start and after completion.

5. A robot position control system based on dynamic safety domain according to claim 4, characterized in that: The control of the robot position to complete the operation specifically includes: The control module sends a beat signal to the safety module, the safety module updates all dynamic safety domains, the perception module obtains the current position, the planning module plans a motion trajectory according to the current position and the target position, and the control module controls the robot position according to the motion trajectory; The target position includes the point position directly recorded by the control module, and also includes the real-time perception result of the perception module using the visual sensor; When planning, the planning module may directly use the safety domain to plan a motion trajectory that will not cause collision, or may plan only based on the current position and the target position. The safety module determines whether a collision occurs based on the trajectory and the current safety domain.

6. According to the robot position control system based on dynamic safety domain of claim 5, a robot position control method based on dynamic safety domain is implemented, characterized in that: The method comprises the following steps: Step S501: Initialize the robot safety domain; Step S502: Obtain robot position information; Step S503: generating a motion trajectory according to the position information, and the robot executes the motion trajectory if the motion trajectory is safe; Step S504: Update the robot safety domain and repeat steps S502 to S504 until the operation is completed.

7. The robot position control method based on dynamic safety domain according to claim 6, characterized in that: Generating the motion trajectory at least includes: Traversing the safety domain, and determining all safety domains required for motion trajectory planning according to the safety space of the safety domain; Under the premise of not crossing the security boundary of the security domain, an optimal path from the current position to the target position is generated.

8. The robot position control method based on dynamic safety domain according to claim 7, characterized in that: The updating of the robot safety domain at least includes: Traversing the security domain update rules, and updating the corresponding dynamic security domain according to the update rules after the current position control beat is completed and before the next position control beat starts; The safe space update comprises at least the steps of: calculating the model collision boundary according to the model index of the update rule and the offset of the model in the safe space; Update the security boundaries of the security domain according to the change of update rules.

9. The robot position control method based on dynamic safety domain according to claim 8, characterized in that: The change method includes at least two operations: adding and deleting: The adding operation merges all external faces of the safety boundary and the model collision boundary, removes all faces of the internal overlapping area, and includes at least: Merge the spatial face set of the safety boundary and the model collision boundary; Remove the occluded internal faces through the intersection algorithm; Keep the outer surface as the new safety boundary; The deletion operation: removing the part of the safety boundary that overlaps with the model collision boundary and generating a new boundary, at least includes: Cut the surface of the safety boundary with the surface of the model collision boundary; Keep the faces in the safety boundary that are outside the model's collision boundary; Add the intersection surface of the model collision boundary and safety boundary to close the cutout.

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