WO2024045091A1 - Motion planning method, apparatus and system for actuator, and storage medium - Google Patents

Abstract

A motion planning method for an actuator (13), the method comprising: determining a sequence in which an end effector in an actuator (13) accesses a plurality of objects in the same plane; determining a dynamic constraint condition of the actuator (13); executing motion planning of the actuator (13) on the basis of the sequence and the dynamic constraint condition; generating a motion control instruction of the actuator (13) on the basis of the motion planning result, wherein the motion control instruction is adapted to control over the motion of the actuator (13), such that the total time spent by the end effector in sequentially accessing the plurality of objects in the same plane is the shortest; and sending the motion control instruction. The method can optimize the cycle time of a planar sequencing task, improve the operation efficiency, and may also be integrated with edge computing; and an access sequence and motion planning are autonomously determined on an edge side, thereby reducing the control workload of an actuator. Further provided in the present application are a motion planning apparatus and system for an actuator, and a storage medium.

Description

Motion planning method, device, system and storage medium of actuator Technical field

The present invention relates to the field of motion control technology, in particular to motion planning methods, devices, systems and storage media for actuators.

Background technique

Planar sequencing tasks are widely used in production. How to plan and control the movement of the actuator to optimize the cycle time in planar sequencing tasks is a difficult problem that has yet to be solved.

Take the plane sorting task of repairing defects on wooden boards as an example. There will be multiple defects on the flat board, requiring an actuator (e.g., a three-axis gantry machine) to repair (e.g., using glue) the defects on the board in sequence. In Chinese Patent Publication No. CN111376114A, a defect repair process for wood veneer panels is mentioned, but it does not involve how to plan and control the movement of the actuator.

Contents of the invention

The embodiment of the present invention provides a motion planning method, device, system and storage medium for an execution mechanism.

A motion planning method for an actuator, the method includes:

Determine the order in which end effectors in an actuator access multiple targets in the same plane;

Determine the dynamic constraints of the actuator;

Execute motion planning of the actuator based on the sequence and the dynamic constraints;

Motion control instructions of the actuator are generated based on the motion planning results, wherein the motion control instructions are adapted to control the motion of the actuator so that the end effector accesses all the actuators in the same plane in the order. The total time required to achieve multiple goals is the shortest;

Send the motion control instructions.

Therefore, the embodiment of the present invention determines the access sequence of multiple targets, and then plans the optimized motion of the actuator based on the dynamic constraints and access sequence of the actuator to minimize the total time, thereby reducing the cycle time of the plane sorting task and improving Improve work efficiency.

In an exemplary embodiment, determining an order in which the end effector in the execution mechanism accesses multiple targets in the same plane includes at least one of the following:

Determine a first path with the shortest total distance for the end effector to access the plurality of targets, and determine the order based on the first path;

A second path is determined that has the shortest total time when the end effector visits the plurality of targets in Cartesian linear motion, and the sequence is determined based on the second path.

It can be seen that the access sequence can be quickly determined based on multiple methods, that is, path planning can be quickly implemented in multiple ways.

In an exemplary embodiment, determining the dynamic constraints of the execution mechanism includes at least one of the following:

obtaining the dynamic constraints from the motion controller of the actuator via an interface with the motion controller of the actuator;

Obtain the dynamic constraints from the cloud.

Therefore, the dynamic constraints of the actuator can be obtained in various ways, which improves the applicability.

In an exemplary implementation, the dynamic constraints include at least one of the following:

First-order constraints used to constrain the speed of the actuator;

Second-order constraints used to constrain the acceleration of the actuator.

It can be seen that first-order constraints on velocity can be implemented, and second-order constraints on acceleration can also be implemented, which enriches the constraint conditions.

In an exemplary implementation, sending the motion control instruction includes:

When the interpolation period of the motion control instruction is less than or equal to a predetermined threshold, sending the motion control instruction to the motion controller of the actuator, so that the motion controller executes the motion control instruction;

When the interpolation period of the motion control instruction is greater than a predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate an interpolated motion control instruction, and the interpolated motion control instruction is sent to the The motion controller of the actuator is used to execute the interpolated motion control instruction by the motion controller.

Therefore, different processing logic can be implemented based on the interpolation cycle, ensuring control accuracy.

A motion planning device for an actuator, the device includes:

a first determining module configured to determine an order in which the end effector in the actuator accesses multiple targets in the same plane;

a second determination module configured to determine the dynamic constraints of the actuator;

a motion planning module configured to execute motion planning of the actuator based on the sequence and the dynamic constraints;

an instruction generation module configured to generate a motion control instruction of the actuator based on the motion planning result, wherein the motion control instruction is adapted to control the movement of the actuator so that the end effector moves in the same plane The total time required to access the multiple targets in the order is the shortest;

A sending module configured to send the motion control instruction.

Therefore, the embodiment of the present invention determines the access sequence of multiple targets, and then plans the optimized motion of the actuator based on the dynamic constraints and access sequence of the actuator to minimize the total time, thereby reducing the cycle time of the plane sorting task and improving Improve work efficiency.

In an exemplary implementation, the first determining module is configured to perform at least one of the following:

Determine a first path with the shortest total distance for the end effector to access the plurality of targets, and determine the order based on the first path;

A second path is determined that has the shortest total time when the end effector visits the plurality of targets in Cartesian linear motion, and the sequence is determined based on the second path.

It can be seen that the access sequence can be quickly determined based on multiple methods, that is, path planning can be quickly implemented in multiple ways.

In an exemplary implementation, the second determining module is configured to perform at least one of the following:

obtaining the dynamic constraints from the motion controller of the actuator via an interface with the motion controller of the actuator;

Obtain the dynamic constraints from the cloud.

Therefore, the dynamic constraints of the actuator can be obtained in various ways, which improves the applicability.

In an exemplary implementation, the dynamic constraints include at least one of the following:

First-order constraints used to constrain the speed of the actuator;

Second-order constraints used to constrain the actuator's acceleration.

It can be seen that first-order constraints on velocity can be implemented, and second-order constraints on acceleration can also be implemented, which enriches the constraint conditions.

In an exemplary embodiment, the sending module is configured to send the motion control instruction to the motion controller of the actuator when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold, so as to The motion control instruction is executed by the motion controller; when the interpolation period of the motion control instruction is greater than a predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate an interpolated motion control instruction, The interpolated motion control instruction is sent to a motion controller of the actuator, so that the motion controller executes the interpolated motion control instruction.

Therefore, different processing logic can be implemented based on the interpolation cycle, ensuring control accuracy.

A motion planning system for an actuator, including:

a motion controller configured to control the movement of the actuator;

The edge device includes a first interface and a second interface;

wherein the edge device is configured to: determine an order in which end effectors in the actuator access multiple targets in the same plane; receive dynamic constraints of the actuator from the motion controller based on the first interface Conditions; executing motion planning of the actuator based on the sequence and the dynamic constraints; generating motion control instructions of the actuator based on motion planning results, wherein the motion control instructions are adapted to control the actuator. Move so that the total time for the end effector to access the plurality of targets in the same plane in the order is shortest; send the motion control instruction to the motion controller via the second interface.

Therefore, the embodiment of the present invention determines the access sequence of multiple targets, and then plans the optimized motion of the actuator based on the dynamic constraints and access sequence of the actuator to minimize the total time, thereby reducing the cycle time of the plane sorting task and improving Improve work efficiency. Moreover, by integrating with edge computing, the access sequence and motion planning can be independently determined on the edge side, reducing the control workload of the actuator.

In an exemplary embodiment, the edge device is configured to send the motion control instruction to the motion controller of the actuator when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold. The motion control instruction is executed by the motion controller; when the interpolation period of the motion control instruction is greater than a predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate an interpolated motion control instruction, The interpolated motion control instruction is sent to a motion controller of the actuator, so that the motion controller executes the interpolated motion control instruction.

An edge device that includes:

processor;

memory for storing executable instructions for the processor;

The processor is configured to read the executable instructions from the memory and execute the executable instructions to implement the motion planning method of the execution mechanism as described in any one of the above.

A computer-readable storage medium has computer instructions stored thereon. When the computer instructions are executed by a processor, the motion planning method of an execution mechanism as described in any one of the above items is implemented.

A computer program product includes a computer program that implements the motion planning method of an execution mechanism as described in any one of the above items when the computer program is executed by a processor.

Description of drawings

Preferred embodiments of the present invention will be described in detail below to make the above and other features and advantages of the present invention more apparent to those skilled in the art with reference to the accompanying drawings, in which:

Figure 1 is a flow chart of a motion planning method of an actuator according to an embodiment of the present invention.

FIG. 2 is an exemplary schematic diagram of the motion planning process of the motion planning system according to the embodiment of the present invention.

FIG. 3 is a schematic diagram of determining the repair sequence of defects according to an embodiment of the present invention.

Figure 4 is a schematic diagram of joint positions, speeds and accelerations according to an embodiment of the present invention.

Figure 5 is an exemplary schematic diagram of the movement of the control actuator according to the embodiment of the present invention.

Figure 6 is an exemplary structural diagram of a motion planning device of an actuator according to an embodiment of the present invention.

Figure 7 is an exemplary structural diagram of an edge device according to an embodiment of the present invention.

Among them, the reference signs are as follows:

label	meaning
100	Motion planning method for actuators
101～105	step
10	visual system
11	edge device
12	Motion Controller
13	executive agency
14	Defect detection processing
15	sequence determination processing
16	motion planning processing
17	Dynamic constraint acquisition processing
18	first interface
19	Motion control instruction generation processing
30	Second interface
31	Command receiving interface
32	Motion control kernel (Kernel)
33	Status interface
41	The position curve of the first joint
42	The position curve of the second joint
43	The speed curve of the first joint
44	The speed curve of the second joint

45	Acceleration curve of the first joint
46	Acceleration curve of the second joint
20	Robot controller
twenty one	Bracket
twenty two	bottom joint
twenty three	shoulder joint
twenty four	elbow joint
25	first wrist joint
26	second wrist joint
27	third wrist joint
28	edge device
29	visual system
600	Motion planning device for actuators
601	First determination module
602	second determination module
603	motion planning module
604	Instruction generation module
605	Send module
700	edge device
701	processor
702	memory

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to examples.

For the sake of simplicity and intuitiveness in description, the solution of the present invention is explained below by describing several representative embodiments. A large number of details in the embodiments are only used to help understand the solution of the present invention. However, it is obvious that the technical solution of the present invention may not be limited to these details when implemented. In order to avoid unnecessarily obscuring the solutions of the present invention, some embodiments are not described in detail, but only give a framework. Hereinafter, "including" means "including but not limited to", and "based on..." means "at least based on..., but not limited to only based on...". Due to Chinese language habits, when the number of a component is not specified below, it means that the component can be one or more, or it can be understood as at least one.

For the plane sorting task, the embodiment of the present invention optimizes the target access sequence, and combines the dynamic constraints of the actuator with the target access sequence, and also optimizes the motion planning of the actuator. In particular, by integrating the embodiments of the present invention into edge devices that interact with the motion control system, a flexible and safe actuator motion planning and control scheme can be realized.

Figure 1 is a flow chart of a motion planning method of an actuator according to an embodiment of the present invention.

As shown in Figure 1, the motion planning method 100 of an actuator includes:

Step 101: Determine the order in which the end effectors in the actuator access multiple targets in the same plane.

Here, the actuator may be an actuator of a robot or any other automated equipment suitable for performing plane sorting tasks. Robots can include industrial robots, service robots, and special robots, among others. Industrial robots include multi-joint manipulators or multi-degree-of-freedom machine devices that are widely used in the industrial field. They have a certain degree of automation and can rely on their own power energy and control capabilities to achieve various industrial processing and manufacturing functions.

Take industrial robots as an example. The arm of the industrial robot body generally adopts a spatial open-chain linkage mechanism. The kinematic pair (rotating pair or moving pair) is often called a joint. The number of joints is usually the number of degrees of freedom of the industrial robot. For the sake of anthropomorphism, the relevant parts of the industrial robot body are often called the base, waist, arm, wrist, hand (gripper or end effector) and walking part (for mobile robots). End effectors usually refer to tools that are connected to the ends (joints) of the robot and have certain functions. For example, the end effector may include a robot gripper, a robot tool quick changer, a robot collision sensor, a robot rotary connector, a robot pressure tool, a compliance device, a robot spray gun, a robot deburring tool, a robot arc welding gun, and a robot electric welding gun. wait. According to different joint configuration types and motion coordinate forms, robot actuators can be divided into rectangular coordinate type, cylindrical coordinate type, polar coordinate type and joint coordinate type. The robot's actuator can make the robot move with the help of power components according to the command signal sent by the control system. For example, a robot's actuator can include servo motors for joints and mechanical links between joints, etc.

Multiple targets in the same plane can have multiple implementations depending on the specific task. For example, in the defect repair application of flat wooden boards, multiple targets are multiple defects on the same flat wooden board. In steel plate laser drilling applications, multiple targets are multiple holes cut in the steel plate.

The above exemplarily describes typical examples of an actuator, an end effector, and multiple targets in the same plane. Those skilled in the art can realize that this description is only exemplary and is not intended to limit the protection of the embodiments of the present invention. scope.

Here, multiple optional algorithms can be used to determine the order in which the end effector accesses multiple targets in the same plane, such as heuristics, greedy algorithms, genetic algorithms, etc. Multiple metrics can be used to address this sequencing issue. For example, metrics may include: the total distance of the path to visit multiple targets on the plane (visited and only once) or the total time to visit multiple targets in Cartesian linear motion, etc.

In one embodiment, step 101 includes:

(1) Determine the first path with the shortest total distance for the end effector to access multiple targets, and determine the order based on the first path.

For example, based on heuristic algorithms, greedy algorithms and genetic algorithms, determine the total distance of each candidate path in which the end effector visits multiple targets (visited and only once), and determines the shortest total distance. The candidate path is used as the first path, and then the order in which the end effector accesses multiple targets is determined based on the target access sequence in the first path.

(2) Determine the second path with the shortest total time when the end effector visits multiple targets in Cartesian linear motion, and determine the order based on the second path.

For example, based on heuristic algorithms, greedy algorithms and genetic algorithms, it is determined that the end effector visits multiple targets (visiting and only visited once), determine the path with the shortest total time as the second path, and then determine the order in which the end effector accesses multiple targets based on the target access sequence in the second path. .

Step 102: Determine the dynamic constraints of the actuator.

In one embodiment, step 102 determines the dynamic constraints of the actuator including:

(1) Obtain dynamic constraints from the motion controller of the actuator through the interface with the motion controller of the actuator.

For example, the dynamic constraints of the actuator can be obtained through a wireless interface or a wired interface with the motion controller of the actuator.

(2) Obtain dynamic constraints from the cloud.

For example, the dynamic constraints of the actuator can be obtained through the wireless interface with the cloud.

In one embodiment, the dynamic constraints include at least one of the following: a first-order constraint for constraining the speed of the actuator; a second-order constraint for constraining the acceleration of the actuator.

For example, when the actuator is that of a multi-joint robot, for motion with limited joint speeds, the planning constraints can be expressed as generalized first-order constraints, where the generalized first-order constraints are as follows:

Among them: q is the position vector of the joint;

is the velocity vector of the joint;

is the acceleration vector of the joint; A ^v (q) is the first variable coefficient that depends on q; f ^v (q) is the second variable coefficient that depends on q; l ^v (q) is the first-order variable coefficient that depends on q Restrictions. Based on the first-order constraints used to constrain the speed of the actuator, the joint speed limits can be determined. Similarly, the Cartesian speed limit of the end-effector can also be determined based on the first-order constraints used to constrain the speed of the end-effector.

When the actuator is that of a multi-joint robot, for motion with limited joint torque and limited acceleration, the planning constraints can be expressed as generalized second-order constraints, where the generalized second-order constraints are as follows:

Among them: A(q) is the third variable coefficient that depends on q; T is the transpose operation symbol; B(q) is the fourth variable coefficient related to the speed vector of the joint; f(q) is the variable coefficient that depends on q The fifth variable coefficient of l(q) is a second-order constraint that depends on q. Based on the second-order constraints used to constrain the acceleration of the actuator, the joint acceleration limits can be determined. Similarly, the Cartesian acceleration limit of the end-effector can also be determined based on the second-order constraints used to constrain the acceleration of the end-effector.

For different constraints, the values of A ^v (q), f ^v (q), l ^v (q), A (q), B (q), f (q) and l (q) can be derived.

For example, based on the dynamics model:

where M(q) is the inertia matrix;

is the Coriolis force and centripetal force matrix; g(q) is the gravity vector; τ is the joint torque vector. Corresponding to the second-order constraints, A(q)=M(q), B(q)=C(q), f(q)=g(q), l(q) corresponds to the constraint composed of the joint torque vector τ Conditions (upper limit of τ and lower limit of τ). The problem can then be transformed into an optimization problem, which can be solved using various optimization tools such as qpsolver. These constraints can be combined together (e.g., joint velocities and joint accelerations) and treated as different constraints in the optimization problem. The determined motion planning solution needs to meet these constraints.

Step 103: Execute the motion planning of the actuator based on sequence and dynamic constraints.

Here, motion planning is performed on the actuator based on sequence and dynamic constraints. That is, on the premise that the dynamic constraints are met, the movement of the actuator is planned so that the total time for the end effector to access multiple targets in the plane in the order determined in step 101 is the shortest. For example, the planned movement of the actuator can include the following curves of each joint (and/or end effector): (1), time-related position curve; (2), time-related speed curve; (3) ), time-related acceleration curve; (4), time-related torque curve, etc.

Step 104: Generate motion control instructions for the actuator based on the motion planning results, where the motion control instructions are adapted to control the movement of the actuator so that the total time for the end effector to sequentially access multiple targets in the same plane is the shortest.

For example, the generated motion control instruction can carry at least one of the following: (1) joint position; (2) joint position with joint velocity; (3) joint position with velocity and acceleration, and so on. The motion control instructions for controlling the joints of the actuator may also include motion control instructions for the end effector (for example, a tool installed on the actuator). The end effector can be started or stopped as the actuator moves, which is accomplished by applying a constant force on the Z-axis of the actuator. For example, for a wood defect repair application, the repair tool can be started before reaching the defect point or stopped after passing the defect point.

Step 105: Send motion control instructions.

In one embodiment, step 105 includes:

(1) When the interpolation period of the motion control instruction is less than or equal to the predetermined threshold, the motion control instruction is sent to the motion controller of the actuator, so that the motion controller executes the motion control instruction.

(2) When the interpolation period of the motion control instruction is greater than the predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate the interpolated motion control instruction, and the interpolated motion control instruction is sent to the actuator. The motion controller executes the interpolated motion control instructions.

Therefore, different processing logic can be implemented based on the interpolation cycle, ensuring control accuracy.

The embodiment of the present invention also provides a motion planning system for an actuator. FIG. 2 is an exemplary schematic diagram of the motion planning process of the motion planning system according to the embodiment of the present invention.

The motion planning system includes: a motion controller 12, configured to control the movement of the actuator 13; an edge device 11, including a first interface 18 and a second interface 30; wherein the edge device 11 is configured to: determine the end in the actuator 13 The sequence in which the actuator accesses multiple targets in the same plane; receiving the dynamic constraints of the actuator 13 from the motion controller 12 based on the first interface 18; executing the motion planning of the actuator 13 based on the sequence and the dynamic constraints; based on the motion planning results Generate motion control instructions for the actuator 13 , wherein the motion control instructions are adapted to control the motion of the actuator 13 so that the total time for the end effector to access multiple targets sequentially in the same plane is the shortest; move to the actuator 13 via the second interface 30 The controller 12 sends motion control instructions.

In one embodiment, the edge device 11 is configured to send the motion control instruction to the motion controller 12 of the execution mechanism 13 to be executed by the motion controller 12 when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold. Motion control instructions. In one embodiment, the edge device 11, when the interpolation period of the motion control instruction is greater than a predetermined threshold, interpolates the motion trajectory of the motion control instruction to generate an interpolated motion control instruction, and converts the interpolated motion control instruction The instruction is sent to the motion controller 12 of the actuator 13 so that the motion controller 12 executes the interpolated motion control instruction.

Take repairing defects on wooden boards as an example to illustrate Figure 2. The vision system 10 takes a photo of the board and performs a defect detection process 14 based on the photo of the board to determine the coordinates of each defect in the plane of the board. The vision system 10 provides the coordinates of each defect in the plane of the board to the edge device 11 . The edge device 11 uses the coordinates of each defect in the plane of the board to execute the sequence determination process 15 (for example, determine the default starting point of the end effector, and then determine the shortest total distance candidate path that visits all defects in sequence from the default starting point , and then determine the sequence of accessing the defects based on the candidate paths) to determine the sequence of repairing these defects by the end effector (usually a glue spray gun) in the actuator 13 . The motion controller 12 of the actuator 13 provides the first interface 18 of the edge device 11 with the dynamic constraints of the actuator 13 (such as the position limit of each joint, the speed limit of each joint, and the speed limit of each joint) through its own status interface 33. acceleration limit, Cartesian position limit of the end effector, Cartesian speed limit of the end effector, Cartesian acceleration limit of the end effector, etc.).

The dynamic constraint acquisition process 17 sends the dynamic constraints of the actuator 13 to the motion planning process 16 . The motion planning process 16 plans the movement of the actuator 13 based on the sequence provided by the sequence determination process 15 and the dynamic constraints of the actuator 13 to determine the execution when the total time for the actuator 13 to access all defects in sequence in the plane is the shortest. Motion parameters of mechanism 13. For example, the motion parameters include: the time-related position curve of each joint, the time-related velocity curve of each joint, the time-related acceleration curve of each joint, the time-related torque curve of each joint, A time-dependent position profile of the end effector, a time-dependent velocity profile of the end effector, a time-dependent acceleration profile of the end effector, and so on.

When the motion control instruction generation process 19 determines that the interpolation period of the planned motion parameters of the actuator 13 is less than or equal to the predetermined threshold, the motion control instruction generation process 19 carries the planned motion parameters of the actuator 13 in the generated motion control Instructions. The motion control instruction generation process 19 sends the motion control instruction to the instruction receiving interface 31 of the motion controller 12 via the second interface 30 . The instruction receiving interface 31 sends motion control instructions to the motion control core 132 . The motion control core 32 executes the motion control instruction, thereby controlling the movement of the actuator 13 so that the end effector accesses multiple defects in sequence. Among them, when each defect is reached, the end effector starts to perform defect repair work.

When the motion control instruction generation process 19 determines that the interpolation period of the planned motion parameters of the actuator 13 is greater than the predetermined threshold, the dynamic constraint acquisition process 19 interpolates the planned motion trajectory of the motion parameters of the actuator 13 to generate interpolation The supplemented motion control instructions. The motion control instruction generation process 19 sends the interpolated motion control instruction to the instruction receiving interface 31 of the motion controller 12 via the second interface 30 . The instruction receiving interface 31 sends the interpolated motion control instruction to the motion control core 32 . The motion control core 32 executes the interpolated motion control instructions, thereby controlling the movement of the actuator 13 so that the end effector accesses multiple defects in sequence. Alternatively, when the motion control instruction generation process 19 determines that the interpolation period of the planned motion parameters of the actuator 13 is greater than the predetermined threshold, the motion control instruction generation process 19 does not interpolate the planned motion parameters of the actuator 13 , but Carry it in the motion control instruction. The motion control instruction generation process 19 sends the motion control instruction to the instruction receiving interface 31 of the motion controller 12 via the second interface 30 . The instruction receiving interface 31 sends motion control instructions to the motion control core 32 . The motion control core 32 determines that the interpolation period of the motion parameters of the execution mechanism 13 carried in the motion control instruction is greater than a predetermined threshold. The motion control core 32 interpolates the motion trajectory of the motion parameters of the actuator 13 to generate an interpolated motion control instruction, and executes the interpolated motion control instruction, thereby controlling the movement of the actuator 13 so that the end effector follows the Access multiple defects sequentially.

FIG. 3 is a schematic diagram of determining the order of repairing defects according to an embodiment of the present invention. As shown in Figure 3, 20 defects are randomly generated on a two-dimensional plane, represented as points. The order of accessing these points is determined according to the embodiment of the present invention, and the path connecting these points is determined by the access order.

Figure 4 is a schematic diagram of joint positions, speeds and accelerations according to an embodiment of the present invention. In Figure 4, the planned motion curves of the first joint (X-axis of the frame) and the second joint (Y-axis of the frame) are drawn, including the position curve 41 of the first joint, the position curve 42 of the second joint, The speed curve 43 of the first joint, the speed curve 44 of the second joint, the acceleration curve 45 of the first joint and the acceleration curve 46 of the second joint. Among them: the speed of the first joint and the second joint is within the joint speed constraint range (less than 0.8m/s), and the acceleration of the first joint and the second joint is also within the joint acceleration constraint range (less than 1.2m/s ² )).

Table 1 is a schematic table comparing the embodiment of the present invention with the greedy algorithm. In the greedy algorithm, the next closest target is always visited and connected with Cartesian linear motion (straight line motion). It can be seen from Table 1 that for 20 defects, the embodiment of the present invention can reduce the cycle time (for example, the time required to repair all defects) by 29%.

Table 1

In summary, in the embodiment of the present invention, a sequence determination process is first performed: this process is used to determine the access sequence of the target received from the vision system (for example, the detected position on the wooden board). Then, execute the dynamic constraint acquisition process: This process is used to obtain the dynamic constraints of the actuator from the motion control system of the actuator through the status interface, where the dynamic constraints can include joint position limits, joint speed limits, joint acceleration limits, and end execution The Cartesian position limit of the end effector, the Cartesian speed limit of the end effector, the Cartesian acceleration limit of the end effector, and so on. Next, a motion planning process is performed: This process is used to plan motion that satisfies a given target access sequence and dynamic constraints, with the goal of improving cycle times by driving the actuators to their limits. Then, the motion control instruction generation process is executed: this process is responsible for generating motion control instructions and sending the motion control instructions to the motion control system to drive the actuator. Motion control instructions can be used to control an actuator or end effector (for example, a tool mounted on the actuator).

Figure 5 is an exemplary schematic diagram of the movement of the control actuator according to the embodiment of the present invention. In Figure 5, the six-axis robot includes a bottom joint 22, a shoulder joint 23, an elbow joint 24, a first wrist joint 25, a second wrist joint 26 and a third wrist joint 26. An end effector is arranged on the third wrist joint 26. , among which the shoulder joint 23, the elbow joint 24, the first wrist joint 25, the second wrist joint 26 and the third wrist joint 26 are non-bottom joints. The bottom joint 22, the shoulder joint 23, the elbow joint 24, the first wrist joint 25, the second wrist joint 26 and the third wrist joint 26 each have their own degrees of freedom. The bottom joint 22 is arranged on the bracket 21; the shoulder joint 23 is connected in series to the bottom joint 22; the elbow joint 24 is connected in series to the shoulder joint 23; the first wrist joint 25 is connected in series to the elbow joint 24; the second wrist joint 26 is connected in series to the first wrist joint 25 ; The third wrist joint 26 is connected in series to the second wrist joint 26. The robot controller 20 arranged outside the six-axis robot has a Profinet connection with the bottom joint 22 . The bottom joint 22, the shoulder joint 23, the elbow joint 24, the first wrist joint 25, the second wrist joint 26 and the third wrist joint 26 are jointly connected to the CAN bus inside the six-axis robot.

Robot controller 20 is connected to edge device 28 . Edge device 28 is connected to vision system 29 . The vision system 29 takes photos of the board and performs defect detection processing based on the photos of the board to determine the coordinates of each defect in the plane of the board. The vision system 29 provides the coordinates of each defect in the plane of the board to the edge device 28 . The edge device 28 uses the coordinates of each defect in the plane of the board to determine the order in which the end effector on the third wrist joint 26 accesses the multiple defects in the board. Based on this order and the dynamic constraints of the six-axis robot, the edge device 28 determines the sequence of the six-axis robot. Motion execution planning generates motion control instructions for the six-axis robot based on the planning results. The motion control instructions control the motion of the six-axis robot so that the total time for the end effector to access multiple defects sequentially in the plank plane is the shortest. The edge device 28 sends motion control instructions to the robot controller 20, and the robot controller 20 executes the motion control instructions.

Figure 6 is an exemplary structural diagram of a motion planning device of an actuator according to an embodiment of the present invention. As shown in Figure 6, device 600 includes:

The first determination module 601 is configured to determine the order in which the end effector in the execution mechanism accesses multiple targets in the same plane;

The second determination module 602 is configured to determine the dynamic constraints of the actuator;

The motion planning module 603 is configured to execute motion planning of the actuator based on sequence and dynamic constraints;

The instruction generation module 604 is configured to generate motion control instructions for the actuator based on the motion planning results, where the motion control instructions are adapted to control the actuator to access multiple targets sequentially in the same plane in the shortest total time;

The sending module 605 is configured to send motion control instructions.

In one embodiment, the first determination module 601 is configured to perform at least one of the following: determine the first path with the shortest total distance for the end effector to access multiple targets, and determine the order based on the first path; determine when the end effector executes The second path that takes the shortest total time to access multiple targets in Cartesian linear motion, and the order is determined based on the second path.

In one embodiment, the second determination module 602 is configured to perform at least one of the following: obtaining dynamic constraints from the motion controller of the actuator via an interface with the motion controller of the actuator; obtaining from the cloud Dynamic constraints. Preferably, the dynamic constraints include at least one of the following: a first-order constraint for constraining the speed of the actuator; a second-order constraint for constraining the acceleration of the actuator.

In one embodiment, the sending module 605 is configured to send the motion control instruction to the motion controller of the actuator when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold, so that the motion controller executes the motion control instruction. ; When the interpolation period of the motion control instruction is greater than the predetermined threshold, interpolate the motion trajectory of the motion control instruction to generate the interpolated motion control instruction, and send the interpolated motion control instruction to the motion controller of the actuator , so that the motion controller executes the interpolated motion control instructions.

The embodiment of the present invention also provides an edge device. Figure 7 is an exemplary structural diagram of an edge device according to an embodiment of the present invention. As shown in Figure 7, the edge device 700 includes a processor 701, a memory 702, and a computer program stored on the memory 702 and executable on the processor 701. When the computer program is executed by the processor 701, any of the above execution mechanisms are implemented. motion planning method. Among them, the memory 702 can be implemented as various storage media such as electrically erasable programmable read-only memory (EEPROM), flash memory (Flash memory), programmable programmable read-only memory (PROM), etc. The processor 701 may be implemented to include one or more central processing units or one or more field programmable gate arrays, where the field programmable gate array integrates one or more central processing unit cores. Specifically, the central processing unit or central processing unit core may be implemented as a CPU, an MCU, a DSP, or the like.

It should be noted that not all steps and modules in the above-mentioned processes and structure diagrams are necessary, and some steps or modules can be ignored according to actual needs. The execution order of each step is not fixed and can be adjusted as needed. The division of each module is only for the convenience of describing the functional division. In actual implementation, one module can be implemented by multiple modules, and the functions of multiple modules can also be implemented by the same module. These modules can be located on the same device. , or it can be on a different device.

The hardware modules in various embodiments may be implemented mechanically or electronically. For example, a hardware module may include specially designed permanent circuits or logic devices (such as a dedicated processor such as an FPGA or ASIC) to perform specific operations. Hardware modules may also include programmable logic devices or circuits (eg, including general-purpose processors or other programmable processors) temporarily configured by software to perform specific operations. As for the specific use of mechanical means, or the use of dedicated permanent circuits, or the use of temporarily configured circuits (such as configured by software) to implement the hardware modules, it can be decided based on cost and time considerations.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (15)

1. A motion planning method (100) for an actuator, characterized in that the method (100) includes:

   Determine the order in which end effectors in an actuator access multiple targets in the same plane (101);

   Determine the dynamic constraints of the actuator (102);

   Execute motion planning of the actuator based on the sequence and the dynamic constraints (103);

   Motion control instructions of the actuator are generated based on the motion planning results, wherein the motion control instructions are adapted to control the motion of the actuator so that the end effector accesses all the actuators in the same plane in the order. The total time required to describe multiple goals is the shortest (104);

   Send the motion control instructions (105).
2. The method (100) according to claim 1, characterized in that determining the order (101) in which the end effector in the actuator accesses multiple targets in the same plane includes at least one of the following:

   Determine a first path with the shortest total distance for the end effector to access the plurality of targets, and determine the order based on the first path;

   A second path is determined that has the shortest total time when the end effector visits the plurality of targets in Cartesian linear motion, and the sequence is determined based on the second path.
3. The method (100) according to claim 1, characterized in that determining the dynamic constraints (102) of the actuator includes at least one of the following:

   obtaining the dynamic constraints from the motion controller of the actuator via an interface with the motion controller of the actuator;

   Obtain the dynamic constraints from the cloud.
4. The method (100) according to claim 1, characterized in that the dynamic constraints include at least one of the following:

   First-order constraints used to constrain the speed of the actuator;

   Second-order constraints used to constrain the acceleration of the actuator.
5. The method (100) according to any one of claims 1-4, characterized in that sending the motion control instruction (105) includes:

   When the interpolation period of the motion control instruction is less than or equal to a predetermined threshold, sending the motion control instruction to the motion controller of the actuator, so that the motion controller executes the motion control instruction;

   When the interpolation period of the motion control instruction is greater than a predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate an interpolated motion control instruction, and the interpolated motion control instruction is sent to the The motion controller of the actuator is used to execute the interpolated motion control instruction by the motion controller.
6. A motion planning device (600) for an actuator, characterized in that the device (600) includes:

   A first determination module (601) configured to determine an order in which the end effector in the actuator accesses multiple targets in the same plane;

   The second determination module (602) is configured to determine the dynamic constraints of the actuator;

   A motion planning module (603) configured to execute motion planning of the actuator based on the sequence and the dynamic constraints;

   An instruction generation module (604) configured to generate motion control instructions for the actuator based on motion planning results, wherein the motion control instructions are adapted to control the movement of the actuator so that the end effector is at the desired position. The total time for accessing the multiple targets in the same plane in the order is the shortest;

   The sending module (605) is configured to send the motion control instruction.
7. The device (600) according to claim 6, characterized in that the first determining module (601) is configured to perform at least one of the following:

   Determine a first path with the shortest total distance for the end effector to access the plurality of targets, and determine the order based on the first path;

   A second path is determined that has the shortest total time when the end effector visits the plurality of targets in Cartesian linear motion, and the sequence is determined based on the second path.
8. The device (600) according to claim 6, characterized in that the second determination module (602) is configured to perform at least one of the following:

   obtaining the dynamic constraints from the motion controller of the actuator via an interface with the motion controller of the actuator;

   Obtain the dynamic constraints from the cloud.
9. The device (600) according to claim 6, characterized in that the dynamic constraints include at least one of the following:

   First-order constraints used to constrain the speed of the actuator;

   Second-order constraints used to constrain the actuator's acceleration.
10. The device (600) according to any one of claims 6-9, characterized in that,

    The sending module (605) is configured to send the motion control instruction to the motion controller of the actuator when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold. The controller executes the motion control instruction; when the interpolation period of the motion control instruction is greater than a predetermined threshold, the motion trajectory of the motion control instruction is interpolated to generate an interpolated motion control instruction, and the interpolated motion control instruction is The interpolated motion control instruction is sent to the motion controller of the actuator, so that the motion controller executes the interpolated motion control instruction.
11. A motion planning system for an actuator, which is characterized by including:

    a motion controller (12) configured to control the movement of the actuator (13);

    An edge device (11) includes a first interface (18) and a second interface (30);

    wherein the edge device (11) is configured to: determine the order in which the end effector in the actuator (13) accesses multiple targets in the same plane; control the motion from the motion control based on the first interface (18) The controller (12) receives the dynamic constraints of the actuator (13); executes the motion planning of the actuator (13) based on the sequence and the dynamic constraints; generates the actuator (13) based on the motion planning results. ) motion control instructions, wherein the motion control instructions are adapted to control the movement of the actuator (13) so that the end effector accesses the plurality of targets in the same plane in the order. The total time is the shortest; the motion control instruction is sent to the motion controller (12) via the second interface (30).
12. The motion planning system of an actuator according to claim 11, characterized in that:

    The edge device (11) is configured to send the motion control instruction to the motion controller (12) of the actuator (13) when the interpolation period of the motion control instruction is less than or equal to a predetermined threshold. , to execute the motion control instruction by the motion controller (12); when the interpolation period of the motion control instruction is greater than a predetermined threshold, interpolate the motion trajectory of the motion control instruction to generate an interpolated motion control instructions, and send the interpolated motion control instructions to the motion controller (12) of the actuator (13), so that the motion controller (12) executes the interpolated motion. Control instruction.
13. An edge device (700), characterized by including:

    processor(701);

    Memory (702), used to store executable instructions of the processor (701);

    The processor (701) is configured to read the executable instructions from the memory (702) and execute the executable instructions to implement the execution mechanism of any one of claims 1-5. Motion planning methods (100).
14. A computer-readable storage medium with computer instructions stored thereon, characterized in that when the computer instructions are executed by a processor, the motion planning method (100) of the execution mechanism of any one of claims 1-5 is implemented. .
15. A computer program product, characterized in that it includes a computer program that implements the motion planning method (100) of an execution mechanism according to any one of claims 1 to 5 when the computer program is executed by a processor.

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