A Dual-Closed-Loop Multi-Robot Handling Control Method, System and Device Based on a Kinematic Model

Abstract

The present disclosure relates to the technical field of cooperative handling by multiple mobile robots, and particularly to a dual-closed-loop multi-robot handling control method and its system and device based on a kinematic model. Among them, the dual-closed-loop multi-robot handling control method based on the kinematic model includes: obtaining a set of handling trajectory parameters corresponding to a load; through outer-loop control, determining a control speed corresponding to the load according to the set of handling trajectory parameters; through inner-loop control, controlling at least one mobile robot to handle the load according to the control speed. Using the present disclosure can improve the terrain adaptation ability of the multi-robot handling system and reduce the implementation difficulty of the multi-robot handling system.

Description

Technical Field

[0001] The present disclosure relates to the technical field of multi-mobile robot collaborative handling, and in particular, to a double-closed-loop multi-robot handling control method, system, and device based on a kinematic model. Background Art

[0002] With the development of science and technology, mobile robots have been widely used in fields such as warehousing logistics, home service, and planetary exploration. However, in the face of complex handling tasks, a single mobile robot operation has limitations in terms of load capacity and flexibility. Multi-robot collaborative handling can achieve moving large loads with small robots, and at the same time, the flexibility and robustness of the system are greatly improved. However, in related multi-robot collaborative handling systems, mobile robots mostly use Mecanum wheel omnidirectional mobile robots, which are difficult to adapt to uneven roads, and they use a control method based on the system dynamics model, which is relatively complex, resulting in a high implementation difficulty of the system. Summary of the Invention

[0003] The present disclosure provides a double-closed-loop multi-robot handling control method, system, and device based on a kinematic model, mainly aiming to improve the terrain adaptability of the multi-robot handling system and reduce the implementation difficulty of the multi-robot handling system.

[0004] According to one aspect of the present disclosure, there is provided a double-closed-loop multi-robot handling control method based on a kinematic model, including:

[0005] Obtaining a set of handling trajectory parameters corresponding to a load;

[0006] Through outer-loop control, determining a control speed corresponding to the load according to the set of handling trajectory parameters;

[0007] Through inner-loop control, controlling at least one mobile robot to handle the load according to the control speed.

[0008] Optionally, the set of handling trajectory parameters includes a target pose, a target speed, and a real-time pose, and determining the control speed corresponding to the load according to the set of handling trajectory parameters includes:

[0009] Determining a load tracking error according to the target pose and the real-time pose;

[0010] Taking the load tracking error and the target speed as control inputs of a control law in a central controller, and controlling the central controller to use the control law for tracking to obtain the control speed corresponding to the load.

[0011] Optionally, controlling the central controller to use the control law for tracking to obtain the control speed corresponding to the load includes:

[0012] Control the central controller to perform tracking using the kinematic trajectory tracking control rate of the differential drive mobile robot, and obtain the control speed corresponding to the load.

[0013] Optionally, the controlling at least one mobile robot to carry the load according to the control speed includes:

[0014] Control the robot controller to map the control speed to a robot reference speed;

[0015] Control the robot controller to generate a robot control speed according to the robot reference speed, the robot position tracking error corresponding to the at least one mobile robot, and the real-time orientation information;

[0016] Control the at least one mobile robot to carry the load according to the robot control speed.

[0017] Optionally, before the controlling the robot controller to generate a robot control speed according to the robot reference speed, the robot position tracking error corresponding to the at least one mobile robot, and the real-time orientation information, it further includes:

[0018] Monitor the connection joints connected between the at least one mobile robot to obtain the robot position tracking error and the real-time orientation information corresponding to the at least one mobile robot.

[0019] Optionally, the controlling the robot controller to generate a robot control speed according to the generated robot reference speed and the robot position tracking error and the real-time orientation information fed back by the connection joints connected between the at least one mobile robot includes:

[0020] Obtain the robot position tracking error and the real-time orientation information corresponding to the at least one mobile robot;

[0021] Adjust the robot reference speed and the robot position tracking error to obtain an adjusted robot reference speed and an adjusted robot position tracking error;

[0022] Control the robot controller to generate the robot control speed according to the adjusted robot reference speed, the adjusted robot position tracking error, and the real-time orientation information.

[0023] According to another aspect of the present disclosure, a dual-closed-loop multi-robot handling control system based on a kinematic model is provided, including: at least one mobile robot, a load, a carrier plate, connection joints, a load positioning sensor, a central controller, and at least one robot controller; wherein,

[0024] The load positioning sensor is disposed on the load and is used to monitor the real-time pose of the load;

[0025] The at least one mobile robot is connected through the connecting joint and the bearing plate. The bearing plate is used to place the load, and the connecting joint is used to monitor the position tracking error and real-time orientation information corresponding to the at least one mobile robot;

[0026] The central controller is configured to obtain a set of handling trajectory parameters corresponding to the load, and through outer loop control, determine the control speed corresponding to the load according to the set of handling trajectory parameters;

[0027] The robot controller is disposed in the mobile robot, and the robot controller corresponds to the mobile robot one by one. The robot controller is configured to receive the control speed input by the central controller, and through inner loop control, control the at least one mobile robot to handle the load according to the control speed.

[0028] Optionally, the connecting joint includes at least one of the following degrees of freedom:

[0029] Two translational degrees of freedom in the horizontal plane;

[0030] The rotational degree of freedom about the vertical axis.

[0031] Optionally, the mobile robot includes at least one of the following:

[0032] Differential drive mobile robot;

[0033] Four-wheel drive skid-steering mobile robot;

[0034] Tracked mobile robot.

[0035] According to another aspect of the present disclosure, there is provided a dual-closed-loop multi-robot handling control device based on a kinematic model, including:

[0036] A set acquisition unit, configured to obtain a set of handling trajectory parameters corresponding to the load;

[0037] An outer loop control unit, configured to determine the control speed corresponding to the load through outer loop control according to the set of handling trajectory parameters;

[0038] An inner loop control unit, configured to control at least one mobile robot to handle the load according to the control speed through inner loop control.

[0039] Optionally, the set of handling trajectory parameters includes a target pose, a target speed, and a real-time pose. When the outer loop control unit is configured to determine the control speed corresponding to the load according to the set of handling trajectory parameters, it is specifically configured to:

[0040] Determine the load tracking error based on the target pose and the real-time pose;

[0041] Use the load tracking error and the target speed as the control inputs of the control law in the central controller, and control the central controller to perform tracking using the control law to obtain the control speed corresponding to the load.

[0042] Optionally, when the outer loop control unit is used to control the central controller to perform tracking using the control law to obtain the control speed corresponding to the load, it is specifically used for:

[0043] Control the central controller to perform tracking using the kinematic trajectory tracking control law of the differential drive mobile robot to obtain the control speed corresponding to the load.

[0044] Optionally, when the inner loop control unit is used to control at least one mobile robot to carry the load according to the control speed, it is specifically used for:

[0045] Control the robot controller to map the control speed to the robot reference speed;

[0046] Control the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information corresponding to the at least one mobile robot;

[0047] Control the at least one mobile robot to carry the load according to the robot control speed.

[0048] Optionally, before the inner loop control unit controls the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information corresponding to the at least one mobile robot, it is further used for:

[0049] Monitor the connection joints between the at least one mobile robot to obtain the position tracking error and real-time orientation information corresponding to the at least one mobile robot.

[0050] Optionally, when the inner loop control unit is used to control the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information fed back by the connection joints between the at least one mobile robot, it is specifically used for:

[0051] Obtain the robot position tracking error and real-time orientation information corresponding to the at least one mobile robot;

[0052] Adjust the robot reference speed and the robot position tracking error to obtain an adjusted robot reference speed and an adjusted robot position tracking error;

[0053] Control the robot controller to generate the robot control speed according to the adjusted robot reference speed, the adjusted robot position tracking error, and the real-time orientation information.

[0054] According to another aspect of the present disclosure, there is provided a dual-closed-loop multi-robot handling control system based on a kinematic model, including:

[0055] At least one processor; and

[0056] A memory communicatively connected to the at least one processor; wherein,

[0057] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method according to any one of the foregoing aspects.

[0058] According to another aspect of the present disclosure, there is provided a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause the computer to execute the method according to any one of the foregoing aspects.

[0059] According to another aspect of the present disclosure, there is provided a computer program product, including a computer program, where the computer program implements the method according to any one of the foregoing aspects when executed by a processor.

[0060] In one or more embodiments of the present disclosure, by obtaining a set of handling trajectory parameters corresponding to a load; through outer-loop control, determining a control speed corresponding to the load according to the set of handling trajectory parameters; through inner-loop control, controlling at least one mobile robot to handle the load according to the control speed. Therefore, by adopting a closed-loop control that realizes load trajectory tracking based on a kinematic model, compared with a control method based on a system dynamics model, the control method is simple and easy to implement, can reduce the design difficulty of the controller and the difficulty of system implementation, can reduce the external unknown interference brought by the dynamics model control, and the adverse effects brought by the unknown parameters of the system dynamics model (such as load mass uncertainty). At the same time, it is not necessary to use a Mecanum wheel omnidirectional mobile robot, and differential drive mobile robots, four-wheel drive skid-steering mobile robots, tracked mobile robots, etc. with strong terrain adaptability can be introduced into the multi-robot handling system, which can improve the terrain adaptability of the multi-robot handling system.

[0061] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. Description of the Drawings

[0062] The drawings are used to better understand the solution and do not constitute a limitation to the present disclosure. Among them:

[0063] Figure 1 The flow diagram showing the first kinematic model-based dual-closed-loop multi-robot handling control method provided by the embodiments of the present disclosure;

[0064] Figure 2 The flow diagram showing the second kinematic model-based dual-closed-loop multi-robot handling control method provided by the embodiments of the present disclosure;

[0065] Figure 3 The trajectory tracking control diagram of a load provided by the embodiments of the present disclosure;

[0066] Figure 4 The simplified diagram showing a kinematic model-based dual-closed-loop multi-robot handling control system provided by the embodiments of the present disclosure;

[0067] Figure 5 The speed analysis diagram of a mobile robot provided by the embodiments of the present disclosure;

[0068] Figure 6 The control architecture diagram showing a kinematic model-based dual-closed-loop multi-robot handling control method provided by the embodiments of the present disclosure;

[0069] Figure 7 The structural diagram showing a kinematic model-based dual-closed-loop multi-robot handling control system provided by the embodiments of the present disclosure;

[0070] Figure 8 The structural diagram showing a kinematic model-based dual-closed-loop multi-robot handling control device provided by the embodiments of the present disclosure;

[0071] Figure 9 It is a block diagram of a kinematic model-based dual-closed-loop multi-robot handling control system for implementing the kinematic model-based dual-closed-loop multi-robot handling control method of the embodiments of the present disclosure. Detailed Embodiments

[0072] The following describes exemplary embodiments of the present disclosure with reference to the accompanying drawings. Various details of the embodiments of the present disclosure are included to facilitate understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, descriptions of well-known functions and structures are omitted in the following description for clarity and conciseness.

[0073] The present disclosure will be described in detail below with reference to specific embodiments.

[0074] In the first embodiment, as Figure 1 shown, Figure 1 FIG. 10 shows a schematic flow diagram of a first kinematic model-based double-closed-loop multi-machine handling control method provided by an embodiment of the present disclosure. This method can be implemented depending on a computer program and can run on a device for performing the kinematic model-based double-closed-loop multi-machine handling control method. This computer program can be integrated into an application or run as an independent tool-type application. This method can be executed by a kinematic model-based double-closed-loop multi-machine handling control system.

[0075] Specifically, the kinematic model-based double-closed-loop multi-machine handling control method includes:

[0076] S101, obtaining a set of handling trajectory parameters corresponding to the load;

[0077] According to some embodiments, the set of handling trajectory parameters refers to a set formed by parameters required when handling a load. The set of handling trajectory parameters does not specifically refer to a certain fixed parameter. The handling trajectory parameters in the set of handling trajectory parameters include, but are not limited to, the target pose to which the load needs to be handled, the target speed required for handling the load, the real-time pose of the load, etc.

[0078] In some embodiments, the load refers to the handling object. The load does not specifically refer to a certain fixed load.

[0079] It is easy to understand that when the kinematic model-based double-closed-loop multi-machine handling control system performs double-closed-loop multi-machine handling control, the kinematic model-based double-closed-loop multi-machine handling control system can obtain a set of handling trajectory parameters corresponding to the load.

[0080] S102, through outer loop control, determining the control speed corresponding to the load according to the set of handling trajectory parameters;

[0081] According to some embodiments, double closed-loop control refers to two controllers working in series. The output of the outer-loop control serves as the set value of the inner-loop control, and the output of the inner-loop control is used to manipulate the controlled object, thereby achieving a better control effect on the outer-loop controlled quantity. Among them, in the embodiments of the present disclosure, the outer-loop control is used to determine the control speed corresponding to the load according to the set of handling trajectory parameters, and use the control speed corresponding to the load as the set value of the inner-loop control, and the output of the inner-loop control is used to manipulate the mobile robot.

[0082] It is easy to understand that when the double closed-loop multi-robot handling control system based on the kinematic model obtains the set of handling trajectory parameters corresponding to the load, the double closed-loop multi-robot handling control system based on the kinematic model can determine the control speed corresponding to the load according to the set of handling trajectory parameters.

[0083] S103. Through the inner-loop control, control at least one mobile robot to handle the load according to the control speed.

[0084] It is easy to understand that when the double closed-loop multi-robot handling control system based on the kinematic model determines the control speed corresponding to the load according to the set of handling trajectory parameters through the outer-loop control, the double closed-loop multi-robot handling control system based on the kinematic model can, through the inner-loop control, control at least one mobile robot to handle the load according to the control speed.

[0085] In summary, the method provided by the embodiments of the present disclosure includes: obtaining the set of handling trajectory parameters corresponding to the load; through the outer-loop control, determining the control speed corresponding to the load according to the set of handling trajectory parameters; through the inner-loop control, controlling at least one mobile robot to handle the load according to the control speed. Therefore, by adopting a closed-loop control based on the kinematic model to achieve load trajectory tracking, compared with the control method based on the system dynamics model, the control method is simple and easy to implement, which can reduce the design difficulty of the controller and the difficulty of system implementation, can reduce the external unknown interference brought by the control based on the dynamics model, and the adverse effects brought by the unknown parameters of the system dynamics model (such as the uncertainty of the load mass). At the same time, it is not necessary to use a Mecanum wheel omnidirectional mobile robot, and differential drive mobile robots, four-wheel drive skid-steering mobile robots, tracked mobile robots, etc. with strong terrain adaptability can be introduced into the multi-robot handling system, which can improve the terrain adaptability of the multi-robot handling system.

[0086] Please refer to Figure 2 , Figure 2 which shows a schematic flowchart of the second double closed-loop multi-robot handling control method based on the kinematic model provided by the embodiments of the present disclosure. This method can be executed by the double closed-loop multi-robot handling control system based on the kinematic model.

[0087] Specifically, the double closed-loop multi-robot handling control method based on the kinematic model includes:

[0088] S201. Obtain the set of handling trajectory parameters corresponding to the load;

[0089] According to some embodiments, the handling trajectory parameters in the set of handling trajectory parameters include, but are not limited to, the target pose to which the load needs to be handled, the target speed required to handle the load, the real-time pose of the load, etc. Among them, the pose includes coordinates and orientation.

[0090] In some embodiments, the real-time pose of the load can be determined by a load positioning sensor provided on the load.

[0091] In some embodiments, the target pose does not specifically refer to a certain fixed pose. For example, when a position modification instruction for the target pose is obtained, the target pose can change.

[0092] In some embodiments, the target speed does not specifically refer to a certain fixed speed. For example, when a speed modification instruction for the target speed is obtained, the target speed can change.

[0093] It is easy to understand that when performing double-closed-loop multi-machine handling control based on the kinematic model of the double-closed-loop multi-machine handling control system, the double-closed-loop multi-machine handling control system based on the kinematic model can obtain the set of handling trajectory parameters corresponding to the load.

[0094] S202. Through outer-loop control, determine the load tracking error according to the target pose and the real-time pose;

[0095] According to some embodiments, the load tracking error does not specifically refer to a certain fixed error. The load tracking error includes, but is not limited to, the tracking error described by the load in the global coordinate system O-xy, the tracking error described by the load in the load coordinate system B-xy, etc.

[0096] In some embodiments, the tracking error described by the load in the global coordinate system O-xy can be expressed by the following formula:

[0097]

[0098] where, [x beg , y beg , θ beg represents the tracking error described by the load in the global coordinate system O-xy, x beg represents the position tracking error of the load in the x-axis direction, y beg represents the position tracking error of the load in the y-axis direction, θ beg represents the orientation tracking error of the load.

[0099] where, [x br , y br , θbr represents the virtual load coordinate system B r -x r y r coordinates and orientation in the global coordinate system O-xy; θ br represents the x-axis of the global coordinate system O-xy and the virtual load coordinate system B r -x r y r the x r angle between the axes.

[0100] wherein, [x b , y b , θ b represents the pose (coordinates and orientation) of the load in the global coordinate system O-xy, i.e., the real-time pose of the load; θ b represents the angle between the x-axis of the global coordinate system O-xy and the x-axis of the load coordinate system B-xy.

[0101] In some embodiments, the x-axis in the load coordinate system B-xy represents the front direction of the double-closed-loop multi-machine handling control system based on the kinematic model. Point B represents the control point of the double-closed-loop multi-machine handling control system based on the kinematic model. Specifically, when the load is placed on the carrier plate, point B can be selected at the geometric center of the carrier plate.

[0102] In some embodiments, the virtual load coordinate system B r -x r y r is used to represent the target pose (trajectory) and target speed of the load.

[0103] According to some embodiments, the tracking error described by the load in the load coordinate system B-xy can be expressed by the following formula:

[0104]

[0105] wherein, [x be , y be , θ be represents the tracking error described by the load in the load coordinate system B-xy, x be represents the position tracking error in the x-axis direction of the load, y be represents the position tracking error in the y-axis direction of the load, θ be represents the orientation tracking error of the load.

[0106] It is easy to understand that when the double-closed-loop multi-machine handling control system based on the kinematic model obtains the set of handling trajectory parameters corresponding to the load, the double-closed-loop multi-machine handling control system based on the kinematic model can determine the load tracking error through outer loop control according to the target pose and real-time pose in the set of handling trajectory parameters.

[0107] S203. Take the load tracking error and the target speed as the control inputs of the control rate in the central controller, and control the central controller to perform tracking using the control rate to obtain the control speed corresponding to the load.

[0108] According to some embodiments, since the motion control of the load can be equivalent to the trajectory tracking control of a differential drive mobile robot, when the dual closed-loop multi-robot handling control system based on the kinematic model controls the central controller to perform tracking using the control rate to obtain the control speed corresponding to the load, the central controller can be controlled to perform tracking using the differential drive mobile robot kinematic trajectory tracking control rate to obtain the control speed corresponding to the load.

[0109] For example, the dual closed-loop multi-robot handling control system based on the kinematic model can control the central controller with the target speed [v br , w br of the load, and the load tracking error [x be , y be , θ be in the load coordinate system as the control inputs, and generate the control speed [v b , w b corresponding to the load through the differential drive mobile robot kinematic trajectory tracking control rate, as shown in Figure 3 and Figure 4 .

[0110] Among them, [v br , w br represents the target speed of the load described in the virtual load coordinate system B r -x r y r ; v br represents the target linear velocity, and w br represents the target angular velocity. [v b , w b represents the control speed of the load described in the load coordinate system B-xy; v b represents the control linear velocity, and w b represents the control angular velocity.

[0111] In some embodiments, when the dual closed-loop multi-robot handling control system based on the kinematic model takes the load tracking error and the target speed as the control inputs of the control rate in the central controller, and controls the central controller to perform tracking using the control rate to obtain the control speed corresponding to the load, the state equation of the load can be expressed as:

[0112]

[0113] In some embodiments, the control rate can be in the following form:

[0114]

[0115] Among them, k1, k2, and k3 all represent control gain parameters, and k1, k2, and k3 are all positive numbers greater than zero.

[0116] It is easy to understand that when the double-closed-loop multi-robot handling control system based on the kinematic model determines the load tracking error according to the target pose and the real-time pose in the set of handling trajectory parameters through outer-loop control, the double-closed-loop multi-robot handling control system based on the kinematic model can use the load tracking error and the target speed as the control inputs of the control law in the central controller, and control the central controller to track the control law to obtain the control speed corresponding to the load. And control the central controller to send the control speed corresponding to the load to all robot controllers in a wired or wireless manner.

[0117] S204, through inner-loop control, control the robot controller to map the control speed to the robot reference speed;

[0118] According to some embodiments, in the double-closed-loop multi-robot handling control system based on the kinematic model, it further includes representing the ith connecting joint coordinate system A i -x i y i , and representing the ith robot coordinate system C i -x i y i . Among them, i is a positive integer.

[0119] In some embodiments, each axis of the coordinate system A i -x i y i is parallel to each axis of the coordinate system B-xy; the coordinate system A i -x i y i can be obtained by translating the coordinate system B-xy by (r xi , r yi ). Among them, the point A i represents the connection point of the ith connecting joint and the carrier plate. [r xi , r yi represents the coordinates of the point A i in the load coordinate system B-xy.

[0120] In some embodiments, when the double-closed-loop multi-robot handling control system based on the kinematic model is in the initial state, each axis of the coordinate system C i -x i y i is parallel to each axis of the coordinate system A i -x i y iThe corresponding axes are kept parallel, and at the same time, point A i and point C i coincide in the vertical direction. Among them, point C i represents the connection point of the i-th connecting joint to the robot. The x i axis represents the direction of the front of the mobile robot.

[0121] According to some embodiments, in the double-closed-loop multi-robot handling control system based on the kinematic model, if all the C i points and A i points coincide in the vertical direction during the operation of the system, then the double-closed-loop multi-robot handling control system based on the kinematic model can operate stably. Therefore, by describing the movement of point A i with a virtual robot and allowing the mobile robot to track the movement of the virtual robot in real time, the system is expected to operate stably, as Figure 5 shown. Therefore, the motion control of the mobile robot is also equivalent to the trajectory tracking control of the differential drive mobile robot.

[0122] In some embodiments, when the robot controller maps the control speed to the robot reference speed, the following formula can be referred to:

[0123]

[0124] where v ri represents the target linear velocity of the i-th mobile robot in the coordinate system A i -x i y i . w ri represents the target angular velocity of the i-th mobile robot in the coordinate system A i -x i y i .

[0125] It is easy to understand that when the double-closed-loop multi-robot handling control system based on the kinematic model obtains the control speed corresponding to the load, the double-closed-loop multi-robot handling control system based on the kinematic model can, through the inner-loop control, control the robot controller to map the control speed to the robot reference speed.

[0126] S205. Monitor the connecting joints between at least one mobile robot to obtain the position tracking error and real-time orientation information corresponding to at least one mobile robot;

[0127] According to some embodiments, when the robot moves, since point A i and point C i will shift, therefore, the offset amount [x ei , y ei, that is, the position tracking error [x ei , y ei of the i-th mobile robot. Meanwhile, the real-time orientation information θ of the i-th mobile robot can also be measured through the connecting joint si .

[0128] It is easy to understand that when the double-closed-loop multi-robot handling control system based on the kinematic model controls the robot controller to map the control speed to the robot reference speed, the double-closed-loop multi-robot handling control system based on the kinematic model can monitor the connecting joints between at least one mobile robot, and obtain the position tracking error and real-time orientation information corresponding to at least one mobile robot.

[0129] S206. Control the robot controller to generate a robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information corresponding to at least one mobile robot

[0130] According to some embodiments, when controlling the robot controller to generate a robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information corresponding to at least one mobile robot, first, the robot position tracking error and real-time orientation information corresponding to at least one mobile robot can be obtained. Then, the robot reference speed and the robot position tracking error can be adjusted to obtain the adjusted robot reference speed and the adjusted robot position tracking error. Finally, control the robot controller to generate a robot control speed according to the adjusted robot reference speed, the adjusted robot position tracking error and the real-time orientation information. Therefore, it can further improve the motion flexibility of the mobile robot.

[0131] In some embodiments, the reference speed and position tracking error of the robot can be adjusted according to the following formula

[0132]

[0133] According to some embodiments, the mobile robot can adopt the same control rate as the load. At this time, the orientation tracking error of the robot can be determined according to the robot position tracking error and real-time orientation information corresponding to the mobile robot. Therefore, the control speed of the mobile robot can be determined according to the orientation tracking error

[0134] In some embodiments, the orientation tracking error of the i-th mobile robot can be determined according to the following formula

[0135] θ ei = atan2(w b r xi cosθ si -(v b - wb r yi )sinθ si ,(v b -w b r yi )cosθ si +w b r xi sinθ si )

[0136] where θ ei represents the orientation tracking error of the i-th mobile robot.

[0137] In some embodiments, the orientation tracking error of the i-th mobile robot can also be determined according to the following formula:

[0138] θ ei = atan2(w b r xi , v bx -w b r yi ) - θ si

[0139] In some embodiments, the control speed of the mobile robot can be expressed as:

[0140]

[0141] where v i represents the linear control speed of the i-th mobile robot in the coordinate system C i -x i y i . w i represents the angular control speed of the i-th mobile robot in the coordinate system C i -x i y i .

[0142] It is easy to understand that when the double-closed-loop multi-robot handling control system based on the kinematic model obtains the position tracking error and real-time orientation information corresponding to at least one mobile robot, the double-closed-loop multi-robot handling control system based on the kinematic model can control the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and real-time orientation information corresponding to at least one mobile robot.

[0143] S207. Control at least one mobile robot to handle the load according to the robot control speed.

[0144] According to some embodiments, when controlling at least one mobile robot to handle the load according to the robot control speed, the control speed of the mobile robot, that is, in the coordinate system Ci -x i y i in the control linear velocity in and the coordinate system C i -x i y i in the control angular velocity in, combined with the structural parameters of the mobile robot, convert the control linear velocity and the control angular velocity into the control angular velocity of the wheels of the mobile robot, and then control the mobile robot according to the control angular velocity of the wheels, so that all mobile robots perform movements and cooperate to carry the load.

[0145] In some embodiments, Figure 6 shows a schematic diagram of the control architecture of a dual-closed-loop multi-robot handling control method provided by an embodiment of the present disclosure. As Figure 6 shown, according to the initial point and the target point of the load, a target pose sequence and a target speed sequence of the load can be generated through trajectory generation. Thus, the dual-closed-loop multi-robot handling control system based on the kinematic model can sequentially loop through steps S201-S207, and can enable multiple mobile robots to cooperate to carry the load along the target trajectory from the initial point to the target point. Among them, the kinematic trajectory tracking controller is the robot controller.

[0146] It is easy to understand that when the dual-closed-loop multi-robot handling control system based on the kinematic model obtains the robot control speed, the dual-closed-loop multi-robot handling control system based on the kinematic model can control at least one mobile robot to carry the load according to the robot control speed.

[0147] In summary, for the method provided in the embodiments of the present disclosure, by obtaining the set of handling trajectory parameters corresponding to the load, through outer loop control, the load tracking error is determined according to the target pose and the real-time pose, and the load tracking error and the target speed are used as the control inputs of the control law in the central controller, and the central controller is controlled to track the control law to obtain the control speed corresponding to the load. Through inner loop control, the robot controller is controlled to map the control speed to the robot reference speed, the connection joints connected between at least one mobile robot are monitored to obtain the position tracking error and the real-time orientation information corresponding to at least one mobile robot, and the robot controller is controlled to generate the robot control speed according to the robot reference speed and the robot position tracking error and the real-time orientation information corresponding to at least one mobile robot, and at least one mobile robot is controlled to handle the load according to the robot control speed. Therefore, by equating the trajectory control of the load to the trajectory tracking control of the differential drive mobile robot, and at the same time equating the motion control of the handling mobile robot to the trajectory tracking control of the differential drive mobile robot, through the implementation of closed-loop control for load trajectory tracking based on the kinematic model, compared with the control method based on the system dynamics model, the control method is simple and easy to implement, can reduce the design difficulty of the controller and the difficulty of system implementation, can reduce the external unknown interference brought by the control based on the dynamics model, and the adverse effects brought by the unknown parameters of the system dynamics model (such as the uncertainty of the load mass). At the same time, there is no need to use the omnidirectional mobile robot with Mecanum wheels, and differential drive mobile robots with strong terrain adaptability, four-wheel drive skid-steering mobile robots, tracked mobile robots, etc. can be introduced into the multi-robot handling system, which can improve the terrain adaptability of the multi-robot handling system.

[0148] In the technical solution of the present disclosure, the collection, storage, use, processing, transmission, provision, and disclosure of the user's personal information involved are all in compliance with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0149] According to the embodiments of the present disclosure, the present disclosure also provides a dual-closed-loop multi-robot handling control system based on a kinematic model. Figure 7 FIG. shows a schematic structural diagram of a dual-closed-loop multi-robot handling control system based on a kinematic model provided by an embodiment of the present disclosure. As Figure 7 shown, the dual-closed-loop multi-robot handling control system based on a kinematic model includes: at least one mobile robot 3, a load, a carrier plate 1, connection joints 2, a load positioning sensor, a central controller, and at least one robot controller; wherein,

[0150] The load positioning sensor is disposed on the load and is used for monitoring the real-time pose of the load;

[0151] At least one mobile robot is connected by a connecting joint 2 and a carrier plate 1. The carrier plate 1 is used to place a load, and the connecting joint 2 is used to monitor the position tracking error and real-time orientation information corresponding to at least one mobile robot;

[0152] A central controller is configured to obtain a set of handling trajectory parameters corresponding to the load, and through outer-loop control, determine the control speed corresponding to the load according to the set of handling trajectory parameters;

[0153] The robot controller is disposed in the mobile robot 3, and the robot controller corresponds to the mobile robot 3 one by one. The robot controller 3 is configured to receive the control speed input by the central controller, and through inner-loop control, control at least one mobile robot to handle the load according to the control speed.

[0154] According to some embodiments, the load, the load positioning sensor, the central controller, and at least one robot controller are not shown in Figure 7 the figure.

[0155] In some embodiments, the central controller is respectively connected to at least one robot controller 3. The connection methods include but are not limited to wired connection, wireless connection, etc. When the robot controller 3 receives the control speed input by the central controller, it can receive the control speed input by the central controller through wired connection, wireless connection, etc.

[0156] Optionally, the connecting joint includes at least one of the following degrees of freedom:

[0157] Two translational degrees of freedom in the horizontal plane;

[0158] A rotational degree of freedom about the vertical axis.

[0159] Optionally, the mobile robot includes at least one of the following:

[0160] Differential drive mobile robot;

[0161] Four-wheel drive skid-steering mobile robot;

[0162] Tracked mobile robot.

[0163] In summary, the system provided by the embodiments of the present disclosure includes at least one mobile robot, a load, a carrier plate, a connecting joint, a load positioning sensor, a central controller, and at least one robot controller. Among them, the load positioning sensor is arranged on the load and is used to monitor the real-time pose of the load. At least one mobile robot is connected to the carrier plate through a connecting joint. The carrier plate is used to place the load, and the connecting joint is used to monitor the position tracking error and real-time orientation information corresponding to at least one mobile robot. The central controller is used to obtain the set of handling trajectory parameters corresponding to the load, and through outer-loop control, determine the control speed corresponding to the load according to the set of handling trajectory parameters. The robot controller is arranged in the mobile robot, and the robot controller corresponds to the mobile robot one by one. The robot controller is used to receive the control speed input by the central controller and, through inner-loop control, control at least one mobile robot to handle the load according to the control speed. Therefore, by adopting a closed-loop control that realizes load trajectory tracking based on a kinematic model, compared with the control method based on the system dynamics model, the control method is simple and easy to implement, can reduce the design difficulty of the controller and the implementation difficulty of the system, can reduce the external unknown interference brought by the dynamics model control, and the adverse effects brought by the unknown parameters of the system dynamics model (such as load mass uncertainty). At the same time, there is no need to adopt a Mecanum wheel omnidirectional mobile robot. Differential drive mobile robots, four-wheel drive skid-steering mobile robots, tracked mobile robots, etc. with strong terrain adaptability can be introduced into the multi-robot handling system, which can improve the terrain adaptability of the multi-robot handling system.

[0164] In the technical solution of the present disclosure, the collection, storage, use, processing, transmission, provision, and disclosure of the user's personal information involved all comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0165] The following are the device embodiments of the present disclosure, which can be used to execute the method embodiments of the present disclosure. For the details not disclosed in the device embodiments of the present disclosure, please refer to the method embodiments of the present disclosure.

[0166] Please refer to Figure 8 , which shows a schematic structural diagram of a first double-closed-loop multi-robot handling control device based on a kinematic model provided by the embodiments of the present disclosure. The double-closed-loop multi-robot handling control device based on the kinematic model can be implemented as all or part of the device through software, hardware, or a combination of both. The double-closed-loop multi-robot handling control device 800 based on the kinematic model includes a set acquisition unit 801, an outer-loop control unit 802, and an inner-loop control unit 803, where:

[0167] The set acquisition unit 801 is used to obtain the set of handling trajectory parameters corresponding to the load;

[0168] The outer loop control unit 802 is configured to determine the control speed corresponding to the load according to the set of handling trajectory parameters through outer loop control.

[0169] The inner loop control unit 803 is configured to control at least one mobile robot to handle the load according to the control speed through inner loop control.

[0170] Optionally, the set of handling trajectory parameters includes the target pose, the target speed, and the real-time pose. When the outer loop control unit 802 is configured to determine the control speed corresponding to the load according to the set of handling trajectory parameters, it is specifically configured to:

[0171] Determine the load tracking error according to the target pose and the real-time pose;

[0172] Use the load tracking error and the target speed as the control inputs of the control law in the central controller, and control the central controller to perform tracking using the control law to obtain the control speed corresponding to the load.

[0173] Optionally, when the outer loop control unit 802 is configured to control the central controller to perform tracking using the control law to obtain the control speed corresponding to the load, it is specifically configured to:

[0174] Control the central controller to perform tracking using the kinematic trajectory tracking control law for differential drive mobile robots to obtain the control speed corresponding to the load.

[0175] Optionally, when the inner loop control unit 803 is configured to control at least one mobile robot to handle the load according to the control speed, it is specifically configured to:

[0176] Control the robot controller to map the control speed to the robot reference speed;

[0177] Control the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and the real-time orientation information corresponding to at least one mobile robot;

[0178] Control at least one mobile robot to handle the load according to the robot control speed.

[0179] Optionally, before the inner loop control unit 803 is configured to control the robot controller to generate the robot control speed according to the robot reference speed and the robot position tracking error and the real-time orientation information corresponding to at least one mobile robot, it is further configured to:

[0180] Monitor the connection joints between at least one mobile robot to obtain the position tracking error and the real-time orientation information corresponding to at least one mobile robot.

[0181] Optionally, the inner loop control unit 803 is used to control the robot controller to generate a robot control speed based on the robot reference speed, the robot position tracking error, and the real-time orientation information of the connection joints between at least one mobile robot. Specifically, it is used for:

[0182] Obtain the robot position tracking error and the real-time orientation information corresponding to at least one mobile robot;

[0183] Adjust the robot reference speed and the robot position tracking error to obtain an adjusted robot reference speed and an adjusted robot position tracking error;

[0184] Control the robot controller to generate a robot control speed based on the adjusted robot reference speed, the adjusted robot position tracking error, and the real-time orientation information.

[0185] It should be noted that when the double-closed-loop multi-robot handling control device based on the kinematic model provided in the above embodiment executes the double-closed-loop multi-robot handling control method based on the kinematic model, only the above-mentioned division of each functional module is used for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the double-closed-loop multi-robot handling control device based on the kinematic model provided in the above embodiment and the embodiment of the double-closed-loop multi-robot handling control method based on the kinematic model belong to the same concept. The implementation process is detailed in the method embodiment and will not be repeated here.

[0186] In summary, for the device provided in the embodiments of the present disclosure, the set acquisition unit acquires the set of handling trajectory parameters corresponding to the load; the outer loop control unit determines the control speed corresponding to the load according to the set of handling trajectory parameters through outer loop control; the inner loop control unit controls at least one mobile robot to handle the load according to the control speed through inner loop control. Therefore, by adopting a closed-loop control for load trajectory tracking based on the kinematic model, compared with the control method based on the system dynamics model, the control method is simple and easy to implement, which can reduce the design difficulty of the controller and the implementation difficulty of the system, and can reduce the external unknown interference brought by the control based on the dynamics model and the adverse effects brought by the unknown parameters of the system dynamics model (such as the uncertainty of the load mass). At the same time, it is not necessary to use a Mecanum wheel omnidirectional mobile robot, and differential drive mobile robots, four-wheel drive skid-steering mobile robots, tracked mobile robots, etc. with strong terrain adaptability can be introduced into the multi-robot handling system, which can improve the terrain adaptability of the multi-robot handling system.

[0187] In the technical solution of the present disclosure, the processing of the user's personal information, such as collection, storage, use, processing, transmission, provision, and disclosure, complies with the provisions of relevant laws and regulations and does not violate public order and good customs.

[0188] According to an embodiment of the present disclosure, the present disclosure also provides a dual-closed-loop multi-machine handling control system based on a kinematic model, a readable storage medium, and a computer program product.

[0189] Figure 9 A schematic block diagram of an exemplary dual-closed-loop multi-machine handling control system 900 based on a kinematic model that can be used to implement the embodiments of the present disclosure is shown. The components shown herein, their connections and relationships, and their functions are merely exemplary and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0190] As Figure 9 shown, the dual-closed-loop multi-machine handling control system 900 based on a kinematic model includes a computing unit 901, which can execute various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 902 or a computer program loaded from a storage unit 908 into a random access memory (RAM) 903. In the RAM 903, various programs and data required for the operation of the dual-closed-loop multi-machine handling control system 900 can also be stored. The computing unit 901, the ROM 902, and the RAM 903 are connected to each other via a bus 904. An input / output (I / O) interface 905 is also connected to the bus 904.

[0191] Multiple components in the dual-closed-loop multi-machine handling control system 900 are connected to the I / O interface 905, including: an input unit 906, such as a keyboard, a mouse, etc.; an output unit 907, such as various types of displays, speakers, etc.; a storage unit 908, such as a disk, an optical disc, etc.; and a communication unit 909, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 909 allows the dual-closed-loop multi-machine handling control system 900 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0192] The computing unit 901 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 901 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 901 executes the various methods and processes described above, such as the dual closed-loop multi-machine handling control method based on the kinematic model. For example, in some embodiments, the dual closed-loop multi-machine handling control method based on the kinematic model can be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as the storage unit 908. In some embodiments, part or all of the computer program can be loaded and / or installed onto the dual closed-loop multi-machine handling control system 900 based on the kinematic model via the ROM 902 and / or the communication unit 909. When the computer program is loaded into the RAM 903 and executed by the computing unit 901, one or more steps of the dual closed-loop multi-machine handling control method described above can be executed. Alternatively, in other embodiments, the computing unit 901 can be configured to execute the dual closed-loop multi-machine handling control method based on the kinematic model in any other suitable way (e.g., by means of firmware).

[0193] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special or general programmable processor, receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0194] The program code for implementing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowchart and / or block diagram to be implemented. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0195] In the context of the present disclosure, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0196] In order to provide interaction with a user, the systems and techniques described herein may be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0197] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected with each other by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), the Internet, and blockchain networks.

[0198] A computer system can include a client and a server. The client and the server are generally far from each other and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services ("Virtual Private Server", or simply "VPS"). The server can also be a server of a distributed system, or a server combined with blockchain.

[0199] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in this disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and no limitations are imposed herein.

[0200] The above specific embodiments do not constitute a limitation on the protection scope of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure shall be included within the protection scope of this disclosure.

Claims

1. A double-closed-loop multi-machine handling control method based on a kinematic model, characterized in that Including: Obtaining a set of handling trajectory parameters corresponding to the load; Through outer-loop control, determining a control speed corresponding to the load according to the set of handling trajectory parameters; Through inner-loop control, controlling at least one mobile robot to handle the load according to the control speed; wherein, The set of handling trajectory parameters includes a target pose, a target speed, and a real-time pose, and determining the control speed corresponding to the load according to the set of handling trajectory parameters includes: Determining a load tracking error according to the target pose and the real-time pose; Taking the load tracking error and the target speed as control inputs of a control law in a central controller, and controlling the central controller to perform tracking using the control law to obtain the control speed corresponding to the load.

2. The method according to claim 1, wherein The controlling the central controller to perform tracking using the control law to obtain the control speed corresponding to the load includes: Controlling the central controller to perform tracking using a kinematic trajectory tracking control law for a differentially-driven mobile robot to obtain the control speed corresponding to the load.

3. The method according to claim 1, characterized in that, The controlling at least one mobile robot to handle the load according to the control speed includes: Controlling a robot controller to map the control speed to a robot reference speed; Controlling the robot controller to generate a robot control speed according to the robot reference speed, the robot position tracking error corresponding to the at least one mobile robot, and the real-time orientation information; Controlling the at least one mobile robot to handle the load according to the robot control speed.

4. The method according to claim 3, wherein Before the controlling the robot controller to generate a robot control speed according to the robot reference speed, the robot position tracking error corresponding to the at least one mobile robot, and the real-time orientation information, it further includes: Monitoring a connection joint connecting the at least one mobile robot to obtain the robot position tracking error and the real-time orientation information corresponding to the at least one mobile robot.

5. The method according to claim 3, characterized in that The controlling the robot controller to generate a robot control speed according to the robot reference speed, the robot position tracking error fed back by the connection joint connecting the at least one mobile robot, and the real-time orientation information includes: Obtaining the robot position tracking error and the real-time orientation information corresponding to the at least one mobile robot; Adjusting the robot reference speed and the robot position tracking error to obtain an adjusted robot reference speed and an adjusted robot position tracking error; Controlling the robot controller to generate the robot control speed according to the adjusted robot reference speed, the adjusted robot position tracking error, and the real-time orientation information.

6. A dual-closed-loop multi-machine handling control system based on a kinematic model, characterized in that, Including: At least one mobile robot, a load, a carrier plate, a connection joint, a load positioning sensor, a central controller, and at least one robot controller; wherein, The load positioning sensor is disposed on the load and is used for monitoring the real-time pose of the load; The at least one mobile robot is connected through the connecting joint and the bearing plate, the bearing plate is used for placing the load, and the connecting joint is used for monitoring the position tracking error and the real-time orientation information corresponding to the at least one mobile robot; The central controller is configured to obtain a set of handling trajectory parameters corresponding to the load, and through outer-loop control, determine the control speed corresponding to the load according to the set of handling trajectory parameters; The robot controller is disposed in the mobile robot, and the robot controller corresponds to the mobile robot one by one. The robot controller is configured to receive the control speed input by the central controller, and through inner-loop control, control the at least one mobile robot to handle the load according to the control speed.

7. The system according to claim 6, wherein The connecting joint includes at least one of the following degrees of freedom: Two translational degrees of freedom in the horizontal plane; A rotational degree of freedom about the vertical axis.

8. The system according to claim 6, wherein The mobile robot includes at least one of the following: Differential drive mobile robot; Four-wheel drive skid-steering mobile robot; Tracked mobile robot.

9. A dual-closed-loop multi-machine handling control device based on a kinematic model, characterized in that, Comprising: A set acquisition unit configured to acquire a set of handling trajectory parameters corresponding to the load; An outer-loop control unit configured to, through outer-loop control, determine the control speed corresponding to the load according to the set of handling trajectory parameters, wherein the set of handling trajectory parameters includes a target pose, a target speed, and a real-time pose, determine a load tracking error according to the target pose and the real-time pose, use the load tracking error and the target speed as control inputs of a control law in the central controller, and control the central controller to perform tracking using the control law to obtain the control speed corresponding to the load; An inner-loop control unit configured to, through inner-loop control, control at least one mobile robot to handle the load according to the control speed.

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