Robot control method, device, robot and storage medium

Abstract

The embodiments of the present application provide a robot control method, device, robot and storage medium, which belong to the field of robot technology. The method includes: constructing a two-wheeled inverted pendulum model based on a wheel-legged robot; constructing an initial state space equation based on the two-wheeled inverted pendulum model; linearizing the initial state space equation to obtain the state space equation of a linear time-invariant system; obtaining a quadratic performance objective function based on the state space equation of the linear time-invariant system; calculating the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and controlling the wheel-legged robot based on the wheel torque. In this way, the wheel torque of the wheel-legged robot can be quickly determined, the amount of calculation can be reduced, the calculation time can be reduced, and the real-time performance can be improved.

Description

Technical Field

[0001] The present application relates to the field of robotics technology, and in particular to a robot control method, device, robot, and storage medium. Background Art

[0002] Currently, two-wheeled legged robots combine the advantages of wheeled robots' high energy efficiency and speed with the high terrain adaptability of legged robots, making them suitable for a wider range of applications. However, two-wheeled legged robots are susceptible to interference from unknown terrain or human factors during operation, causing them to become unstable and fall. Therefore, an effective and highly robust motion control method is needed to ensure that the robot can respond quickly to external disturbances and maintain a stable posture. Summary of the Invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide a robot control method, device, robot and storage medium.

[0004] In a first aspect, an embodiment of the present application provides a robot control method, the method comprising:

[0005] Construct a two-wheeled inverted pendulum model based on a wheel-legged robot;

[0006] Constructing an initial state space equation according to the two-wheel inverted pendulum model;

[0007] Linearizing the initial state-space equation to obtain a state-space equation of a linear steady-state system;

[0008] Obtaining a quadratic performance objective function based on a state-space equation of the linear time-invariant system;

[0009] The quadratic performance objective function is calculated by a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and the wheel-legged robot is controlled according to the wheel torque.

[0010] In one embodiment, controlling the wheel-legged robot according to the wheel torque includes:

[0011] Using the wheel torque as a control instruction, and inputting the control instruction into the wheel motor of the wheel-legged robot;

[0012] The wheel motor is controlled according to the control instruction to output a torque equal to the wheel torque.

[0013] In one embodiment, the method further comprises:

[0014] After the wheel motor outputs a torque equal to the wheel torque, multiple actual state quantities of the wheel-legged robot are obtained.

[0015] In one embodiment, the method further comprises:

[0016] Performing forward kinematic analysis on the planar five-bar mechanism of the legs of the wheel-legged robot to obtain a set of foot endpoint equations of the wheel-legged robot;

[0017] Obtaining a foot endpoint vector expression according to the foot endpoint equation group;

[0018] Obtaining a velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression;

[0019] Determining a mapping relationship between the velocity Jacobian matrix, the hip joint driving torque vector, and the two-dimensional contact force exerted on the foot endpoint according to the principle of virtual work;

[0020] Adding a virtual spring damper to the wheel-leg robot to construct a feedback control framework;

[0021] The hip joint driving torque of the wheel-legged robot is obtained based on the feedback control framework and the mapping relationship, and the wheel-legged robot is controlled according to the hip joint driving torque.

[0022] In one embodiment, the obtaining of the hip joint driving torque of the wheel-legged robot based on the feedback control framework and the mapping relationship includes:

[0023] calculating the two-dimensional contact force based on the feedback control framework;

[0024] The hip joint driving torque is calculated based on the calculated two-dimensional contact force and the mapping relationship.

[0025] In one embodiment, the step of adding a virtual spring damper to the wheel-legged robot to construct a feedback control framework includes:

[0026] Virtual spring dampers are added in the first direction, the second direction of the foot end of the wheel-legged robot and the rolling direction of the wheel-legged robot to construct a three-channel feedback control framework.

[0027] In one embodiment, the obtaining of the velocity Jacobian matrix of the leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression includes:

[0028] Performing total differential processing on the foot endpoint vector expression to obtain a total differential expression;

[0029] The velocity Jacobian matrix is ​​determined according to the total differential expression.

[0030] In a second aspect, an embodiment of the present application provides a robot control device, the device comprising:

[0031] The first building module is used to build a two-wheeled inverted pendulum model based on the wheel-legged robot;

[0032] A second building module is used to build an initial state space equation according to the two-wheel inverted pendulum model;

[0033] a processing module, configured to linearize the initial state-space equation to obtain a state-space equation of a linear steady-state system;

[0034] An acquisition module, configured to acquire a quadratic performance objective function according to a state-space equation of the linear time-invariant system;

[0035] The control module is used to calculate the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and control the wheel-legged robot according to the wheel torque.

[0036] In a third aspect, an embodiment of the present application provides a robot comprising a memory and a processor, wherein the memory is used to store a computer program, and the computer program executes the robot control method provided in the first aspect when the processor is running.

[0037] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, which executes the robot control method provided in the first aspect when running on a processor.

[0038] The robot control method, device, robot, and storage medium provided in the present application construct a two-wheeled inverted pendulum model based on a wheel-legged robot; construct an initial state-space equation based on the two-wheeled inverted pendulum model; linearize the initial state-space equation to obtain the state-space equation of a linear time-invariant system; obtain a quadratic performance objective function based on the state-space equation of the linear time-invariant system; calculate the quadratic performance objective function using a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and control the wheel-legged robot based on the wheel torque. In this way, the wheel torque of the wheel-legged robot can be quickly determined, reducing the amount of calculation, shortening the calculation time, and improving real-time performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this application and should not be regarded as limiting the scope of protection of this application. In each of the drawings, similar components are numbered similarly.

[0040] Figure 1 A schematic diagram of a flow chart of a robot control method provided by an embodiment of the present application is shown;

[0041] Figure 2 A schematic structural diagram of a wheel-legged robot provided in an embodiment of the present application is shown;

[0042] Figure 3 A schematic structural diagram of a two-wheel inverted pendulum model provided in an embodiment of the present application is shown;

[0043] Figure 4 Another structural schematic diagram of the wheel-leg robot provided in an embodiment of the present application is shown;

[0044] Figure 5 A control schematic diagram of the wheel-leg robot provided by an embodiment of the present application is shown;

[0045] Figure 6 Another schematic diagram of the process of controlling a robot according to an embodiment of the present invention is shown;

[0046] Figure 7 A structural schematic diagram of a robot control device provided in an embodiment of the present application is shown.

[0047] Icons: 700 - robot control device, 701 - first building module, 702 - second building module, 703 - processing module, 704 - acquisition module, 705 - control module. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0049] The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0050] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0051] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0052] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as in the context of the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present application.

[0053] Example 1

[0054] An embodiment of the present application provides a robot control method.

[0055] See also Figure 1 The robot control method includes steps S101 to S105, and each step is described below.

[0056] Step S101: construct a two-wheeled inverted pendulum model based on the wheel-legged robot.

[0057] In this embodiment, the wheel-legged robot can be a two-wheeled, footed robot. This two-wheeled, footed robot has a parallel leg mechanism with numerous leg rods. Building a full dynamics model would result in excessive computational effort, making it difficult to ensure real-time control. To reduce computational effort and improve real-time control, the complex wheel-legged robot is simplified into a two-wheeled inverted pendulum model, and the mass of the leg rods is neglected.

[0058] See Figure 2 , Figure 2 The diagram of the connection of the leg rods on one side of the wheel-legged robot is shown. The wheel 203 is connected to the shaft 203 through the connecting rod 204. The shaft 203 is connected to the shaft on the fuselage 201 through the connecting rod. It should be noted that the left and right sides of the wheel-legged robot have the same leg rod connection relationship. Figure 2 Only one side of the leg rod connection relationship of the wheel-leg robot is shown in FIG. Figure 2 In, f R Represents the friction force on the wheels from the ground, R represents the right wheel, H represents the R Represents the horizontal component of the force exerted by the fuselage and leg connecting rod on the right wheel axle, H stands for horizontal.

[0059] See Figure 3 , Figure 3 The figure shows a schematic diagram of the structure of a two-wheeled inverted pendulum model, which includes wheels 203 and a body 201. Figure 2 The connecting rod and shaft components are simplified to obtain Figure 3 The schematic diagram of the two-wheel inverted pendulum model is shown in Figure 1. Figure 3 In, V R Represents the vertical component of the force exerted by the fuselage and the leg link on the right wheel axle, V is vertical. R Represents the friction force on the wheel from the ground. R Represents the horizontal component of the force exerted by the fuselage and the leg link on the right wheel axle. R Represents right wheel torque, etc.

[0060] Step S102: constructing an initial state space equation according to the two-wheel inverted pendulum model.

[0061] In this embodiment, the wheel-leg robot is simplified into a two-wheeled inverted pendulum model, and the mass of the leg link is ignored. Figure 3 The two-wheeled inverted pendulum model shown uses a simplified back-end two-wheeled inverted pendulum model to construct the control initial state space equation, which can significantly reduce the dynamic solution time.

[0062] For example, the following initial state space equation can be established:

[0063] Formula (1):

[0064] Where M is the body mass of the wheel-legged robot, m is the mass of a single wheel of the wheel-legged robot, R is the wheel radius, D is the distance between the left and right wheels of the wheel-legged robot, L is the distance between the body mass center of the wheel-legged robot and the wheel axle, θ is the angle between the body and the Z axis of the world coordinate system in the forward direction (pitch angle), δ is the angle between the body and the Y axis of the world coordinate system (yaw angle), I ω is the moment of inertia of the wheel around the axis of rotation, I δ is the moment of inertia of the whole machine around the yaw direction, I θ is the moment of inertia of the fuselage around the pitch axis, x is the forward displacement of the fuselage, C l and C r is the output torque of the left and right wheels, Represents the second derivative of the angle of the fuselage around the Y axis of the world coordinate system, Represents the second derivative of the forward displacement of the fuselage.

[0065] Step S103 : linearize the initial state-space equation to obtain the state-space equation of the linear time-invariant system.

[0066] In this embodiment, the state space equation near the equilibrium point is obtained according to formula (1):

[0067] Formula (2):

[0068] Among them, A and B are both constant coefficient matrices, which can be derived from formula (1). Indicates the angle of the fuselage around the Y axis of the world coordinate system. The first derivative of the forward displacement of the fuselage, Represents the first derivative of the angle of the fuselage around the Y-axis of the world coordinate system.

[0069] It should be noted that the process of deriving A and B through formula (1) is to linearize formula (1) and rewrite the equation group into a matrix form to obtain A and B.

[0070] Step S104: obtaining a quadratic performance objective function according to the state-space equation of the linear time-invariant system.

[0071] In this embodiment, the linear quadratic regulator (LQR) is a linear system described in state space in modern control theory, and the objective function is a quadratic function of the object state and the control input. Based on the state space equation of the linear time-invariant system described by formula (2), this solution designs the following quadratic performance objective function:

[0072] Formula (3):

[0073] Among them, x is the n-dimensional state vector, u is the r-dimensional input vector, the weighted matrices Q and R are used to balance the weights of the state vector and the input vector, Q is a semi-positive definite matrix, and R is a positive definite matrix.

[0074] For example, n can be 4, r can be 2, and the n-dimensional state vector is X in formula (2). When n is 4, the 4-dimensional state vector includes the first-order derivative of the robot's forward position (forward velocity), the first-order derivative of the fuselage yaw angle (steering angular velocity), the fuselage pitch angle (forward tilt angle), and the first-order derivative of the fuselage pitch angle (forward tilt angular velocity). When r is 2, the 2-dimensional input vector is u in formula (2), which is the torque input to the left and right wheels by the controller, C l and C r .

[0075] Step S105 , calculating the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torque.

[0076] In this way, the wheel torque of the wheel-legged robot can be quickly determined, which reduces the amount of calculation, reduces the calculation time, and improves real-time performance.

[0077] In this embodiment, step S105 may include:

[0078] Using the wheel torque as a control instruction, and inputting the control instruction into the wheel motor of the wheel-legged robot;

[0079] The wheel motor is controlled according to the control instruction to output a torque equal to the wheel torque.

[0080] Demonstratively, by optimizing the objective function J in formula (3) in real time to minimize it, the corresponding u is obtained, and then u is input as a control instruction to the wheel motor to achieve rapid control of the wheel-legged robot.

[0081] In this embodiment, the robot control method further includes:

[0082] After the wheel motor outputs a torque equal to the wheel torque, multiple actual state quantities of the wheel-legged robot are obtained.

[0083] In this embodiment, multiple actual state quantities are the actual states presented by the wheel-legged robot after control (state transfer). For example, multiple actual state quantities are the actual pitch angle and actual yaw angle of the wheel-legged robot, the actual forward displacement of the fuselage, the measurement value of the foot end position, the height measurement value of the wheel-legged robot's leg, the speed measurement value of the wheel-legged robot's fuselage center of mass, the roll angle measurement value of the wheel-legged robot, the roll angular velocity measurement value, etc.

[0084] See also Figure 5 The robot control method also includes steps S106 to S1012, and each step is described below.

[0085] S106, performing forward kinematic analysis on the planar five-bar mechanism of the legs of the wheel-legged robot to obtain a group of foot endpoint equations of the wheel-legged robot.

[0086] In this embodiment, the length of the two legs of the wheel-legged robot is controlled based on the posture feedback of the Inertial Measurement Unit (IMU), so as to achieve the purpose of stabilizing the lateral rolling posture. F ,like Figure 4 As shown, the wheeled-legged robot's leg planar five-bar mechanism consists of a first kinematic branch ABCD and a second kinematic branch AB'C'D, which are closed at point D at the foot end. Feedback control (PD) is implemented, where P is the proportional coefficient of the state error (feedback term) and D is the damping coefficient of the error (derivative).

[0087] For example, it is necessary to perform a forward kinematics solution on the planar five-bar mechanism of the leg of the wheel-legged robot to obtain the coordinates of the foot endpoints as expressed by the following formula 4.

[0088] Formula 4:

[0089] Where L0 represents the distance between BB', represents the angle of ∠XB'C', Indicates the angle of ∠ABC. The lengths of BC and CD are L1 and L2 respectively, the lengths of B'C' and C'D are L1 and L2 respectively, and the foot end point D is (x d ,y d )express.

[0090] Figure 4 It can be seen that the kinematic branch ABCD and the kinematic branch AB'C'D are closed at point D at the foot end. Based on this geometric relationship, the equation group is established:

[0091] Formula 5:

[0092]

[0093] in, represents the angle of ∠ECD, represents the angle of ∠FC'D, (x d ,y d ) represents the coordinates of point D.

[0094] S107, obtaining a foot endpoint vector expression according to the foot endpoint equation group.

[0095] In this embodiment, VMC (Virtual Model Control) is an intuitive control method. The key is to construct appropriate virtual components on each degree of freedom that needs to be controlled to generate appropriate virtual forces. The virtual force is not the force or torque of the actual actuator, but is converted through the action of the actuator. In order to map the force or torque of the workspace (TaskSpace) into the joint torque of the joint space (JointSpace), a position mapping relationship between the two spaces is required. This position mapping relationship is the forward kinematic model. Equation (5) is expressed in vector form as the following formula:

[0096] Formula (6): x = f(q)

[0097] Where x=[x F y F ] T , q=[φ1 φ2] T ,(x F ,y F ) represents the foot end coordinates.

[0098] It should be noted that Formula 5 is constructed within the scope of geometric analysis, and Formula 6 is constructed within the scope of dynamic modeling, so even if the two represent the same foot end, they are expressed in different forms.

[0099] S108, obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression.

[0100] In this embodiment, S108 includes:

[0101] Performing total differential processing on the foot endpoint vector expression to obtain a total differential expression;

[0102] The velocity Jacobian matrix is ​​determined according to the total differential expression.

[0103] For example, the total differential of formula (5) with respect to x is:

[0104] Formula (7):

[0105] From formula (7), we can know the velocity Jacobian matrix J of the leg parallel mechanism of the wheel-leg robot:

[0106] Formula (8):

[0107] S109, determining a mapping relationship among the velocity Jacobian matrix, the hip joint driving torque vector, and the two-dimensional contact force acting on the foot endpoint according to the principle of virtual work.

[0108] For example, according to the principle of virtual work, the hip joint driving torque vector T = [T1T2] T The two-dimensional contact force F on the foot end point D is [F X F Y ] T The mapping relationship between them:

[0109] Formula (9): T = J T F

[0110] S1010: Add a virtual spring damper to the wheel-leg robot to build a feedback control framework.

[0111] In this embodiment, S1010 includes:

[0112] Virtual spring dampers are added in the first direction, the second direction of the foot end of the wheel-legged robot and the rolling direction of the wheel-legged robot to construct a three-channel feedback control framework.

[0113] For example, virtual spring dampers are added to the X and Y directions of the robot's legs and the body's roll direction, creating a three-channel feedback control framework. It should be noted that the roll direction can also be expressed as the left and right roll direction.

[0114] The feedback control of the foot end in the X direction is expressed by the following formula:

[0115] Formula (10):

[0116] Among them, F XR The F in the equation represents the two-dimensional contact force of the foot, F XR The subscript X in the formula represents the component of the two-dimensional contact force in the X direction, F XR The subscript R in the figure represents the foot end of the right leg of the wheel-legged robot, and F XR represents the component of the two-dimensional contact force in the X direction on the foot end of the right leg of the wheel-legged robot; F XL F in the equation represents the two-dimensional contact force at the foot end, F XL The subscript X in the equation represents the component of the two-dimensional contact force in the Y direction, F XL The subscript L in the figure represents the foot end of the left leg of the wheel-legged robot, and F XL Represents the component of the two-dimensional contact force in the X direction on the foot end of the left leg of the wheel-legged robot.

[0117] x R_des The x in the figure represents the position of the foot end in the x-axis direction of the fuselage coordinate system. R_des The subscript R in the figure represents the foot end of the right leg of the wheel-legged robot, and x R_des The subscript des in the code represents the desired position, and x R_des Represents the desired position of the foot end of the right leg of the wheel-legged robot. L_des The x in the figure represents the position of the foot end in the x-axis direction of the fuselage coordinate system. L_des The subscript L in the figure represents the foot end of the left leg of the wheel-legged robot, and x L_des The subscript des in the code represents the desired position, and x L_des Represents the desired position of the foot end of the wheel-legged robot's left leg.

[0118] Represents the measured value of the foot end position of the right leg of the wheel-legged robot, Represents the measured value of the foot end position of the left leg of the wheel-legged robot. XR_des represents the desired velocity of the right leg of the wheel-legged robot in the x-axis direction of the body coordinate system, v XL_des K represents the expected velocity of the left leg of the wheel-legged robot in the x-axis direction of the body coordinate system. X Indicates the scale factor in the x-axis direction of the fuselage coordinate system. X Represents the damping coefficient in the x-axis direction of the fuselage coordinate system.

[0119] The feedback control in the Y direction of the foot end is expressed by the following formula:

[0120] Formula (11):

[0121] Among them, F YR F represents the component of the two-dimensional contact force in the Y direction on the foot end of the right leg of the wheel-legged robot; YL represents the component of the two-dimensional contact force in the Y direction on the foot end of the left leg of the wheel-legged robot; h des represents the desired height of the wheel-legged robot's body mass center, represents the measurement value of the body mass center of the wheel-legged robot, represents the height measurement value of the left leg of the wheel-legged robot, represents the height measurement of the right leg of the wheel-legged robot; Represents the velocity measurement value of the wheel-legged robot's body mass center in the y-axis direction of the body coordinate system; Represents the velocity measurement value of the left leg of the wheel-legged robot in the y-axis direction of the body coordinate system; K represents the speed measurement value of the right leg of the wheel-legged robot in the y-axis direction of the body coordinate system. y Indicates the scale factor in the y-axis direction of the fuselage coordinate system. y Indicates the damping coefficient in the y-axis direction of the fuselage coordinate system.

[0122] Roll direction of fuselage:

[0123] Formula (12):

[0124] Among them, F YR F represents the component of the two-dimensional contact force in the Y direction on the foot end of the right leg of the wheel-legged robot; YL represents the component of the two-dimensional contact force in the Y direction on the foot end of the left leg of the wheel-legged robot; represents the desired roll angle, Represents the roll angle measurement value of the wheel-legged robot, measured by IMU, ω des represents the desired roll angular velocity, Indicates the roll angular velocity measurement value, measured by IMU. K roll Indicates the proportional coefficient in the rolling direction; D roll Indicates the damping coefficient in the roll direction.

[0125] In this embodiment, the hip joint driving torque is calculated based on formula (9) to formula (12).

[0126] S1011 , obtaining a hip joint driving torque of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torque.

[0127] In this embodiment, S1011 includes:

[0128] calculating the two-dimensional contact force based on the feedback control framework;

[0129] The hip joint driving torque is calculated based on the calculated two-dimensional contact force and the mapping relationship.

[0130] The two-dimensional contact force F acting on point D at the foot end in formula (9) is calculated by formulas (10)-(12). The two-dimensional contact force F acting on point D at the foot end and the velocity Jacobian matrix J are substituted into formula 9 to obtain the driving torque of the hip joint of the wheel-legged robot.

[0131] In this way, the hip joint driving torque of the wheel-leg robot can be quickly obtained, the amount of calculation, the calculation time, and the real-time performance are improved.

[0132] See Figure 6 In this embodiment, the control process of the wheel-leg robot includes: according to the hip joint driving torque T hip and wheel input torque T wheel Determine the control input u. The prototype of the wheel-legged robot sets the angle (yaw angle) δ of the fuselage around the Y axis of the world coordinate system, the angle (pitch angle) φ of the fuselage around the Z axis of the world coordinate system, and the angle (roll angle) of the fuselage around the X axis of the world coordinate system. The angle q of each motor is input into the state estimator. Generally speaking, all robot systems require a state estimator to improve the accuracy of sensor measurement data. Pitch balance and speed tracking are achieved through chassis kinematics solution and LQR, that is, the wheel torque is solved according to steps S101-S105 provided in this embodiment to achieve the control of the wheel torque of the wheel-legged robot. It should be noted that the calculation of T wheel The formula is Among them, T wheel represents the torque vector of the left and right wheels, K(Lc) represents the gain matrix solved by the LQR controller, which is a function of the center of mass height Lc of the fuselage, x d represents the desired system state vector, Represents the measurement value of the current system state vector.

[0133] By solving the joint kinematics, mapping the foot force to the joint torque, the roll balance controller VCM and calculating the desired foot force (feedback + gravity feedforward), the hip joint driving torque is calculated through steps S106-S1012, and the foot force of the robot is controlled according to the hip joint driving torque. Among them, the formula for mapping the foot force to the joint torque is T=J T F, T represents the hip joint driving torque vector, T = [T1T2] T , F represents the two-dimensional contact force on the foot end point D, F=[F X F Y ] T .

[0134] The robot control method provided in this embodiment constructs a two-wheeled inverted pendulum model based on a wheel-legged robot; constructs an initial state-space equation based on the two-wheeled inverted pendulum model; linearizes the initial state-space equation to obtain the state-space equation of a linear time-invariant system; obtains a quadratic performance objective function based on the state-space equation of the linear time-invariant system; calculates the quadratic performance objective function using a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot; and controls the wheel-legged robot based on the wheel torque. In this way, the wheel torque of the wheel-legged robot can be quickly determined, reducing the amount of calculation and computing time, and improving real-time performance.

[0135] Example 2

[0136] In addition, an embodiment of the present application provides a robot control device.

[0137] like Figure 7 As shown, the robot control device 700 includes:

[0138] The first construction module 701 is used to construct a two-wheeled inverted pendulum model based on the wheel-legged robot;

[0139] A second construction module 702 is configured to construct an initial state space equation according to the two-wheeled inverted pendulum model;

[0140] A processing module 703 is used to linearize the initial state-space equation to obtain a state-space equation of a linear time-invariant system;

[0141] An acquisition module 704 is configured to acquire a quadratic performance objective function according to a state-space equation of the linear time-invariant system;

[0142] The control module 705 is used to calculate the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and control the wheel-legged robot according to the wheel torque.

[0143] In one embodiment, the control module 705 is further configured to use the wheel torque as a control instruction and input the control instruction into the wheel motor of the wheel-legged robot;

[0144] The wheel motor is controlled according to the control instruction to output a torque equal to the wheel torque.

[0145] In one embodiment, the control module 705 is further configured to obtain a plurality of actual state quantities of the wheel-legged robot after the wheel motor outputs a torque equal to the wheel torque.

[0146] In one embodiment, the control module 705 is further configured to perform a forward kinematics analysis on the planar five-bar mechanism of the legs of the wheel-legged robot to obtain a set of foot endpoint equations of the wheel-legged robot;

[0147] Obtaining a foot endpoint vector expression according to the foot endpoint equation group;

[0148] Obtaining a velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression;

[0149] Determining a mapping relationship between the velocity Jacobian matrix, the hip joint driving torque vector, and the two-dimensional contact force exerted on the foot endpoint according to the principle of virtual work;

[0150] Adding a virtual spring damper to the wheel-leg robot to construct a feedback control framework;

[0151] The hip joint driving torque of the wheel-legged robot is obtained based on the feedback control framework and the mapping relationship, and the wheel-legged robot is controlled according to the hip joint driving torque.

[0152] In one embodiment, the control module 705 is further configured to calculate the two-dimensional contact force based on the feedback control framework;

[0153] The hip joint driving torque is calculated based on the calculated two-dimensional contact force and the mapping relationship.

[0154] In one embodiment, the control module 705 is further configured to add virtual spring dampers in the first direction, the second direction of the foot end of the wheel-legged robot and in the rolling direction of the wheel-legged robot to construct a three-channel feedback control framework.

[0155] In one embodiment, the control module 705 is further configured to perform total differential processing on the foot endpoint vector expression to obtain a total differential expression;

[0156] The velocity Jacobian matrix is ​​determined according to the total differential expression.

[0157] The robot control device 700 provided in this embodiment can implement the robot control method provided in Example 1, and will not be described again here to avoid repetition.

[0158] The robot control device provided in this embodiment constructs a two-wheeled inverted pendulum model based on a wheel-legged robot; constructs an initial state-space equation based on the two-wheeled inverted pendulum model; linearizes the initial state-space equation to obtain a state-space equation for a linear time-invariant system; obtains a quadratic performance objective function based on the state-space equation for the linear time-invariant system; calculates the quadratic performance objective function using a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and controls the wheel-legged robot based on the wheel torque. In this way, the wheel torque of the wheel-legged robot can be quickly determined, reducing the amount of calculation and computing time, and improving real-time performance.

[0159] Example 3

[0160] In addition, an embodiment of the present application provides a robot, including a memory and a processor, wherein the memory stores a computer program, and when the computer program runs on the processor, it executes the robot control method provided in Example 1.

[0161] The robot provided in this embodiment can implement the robot control method provided in Example 1, and will not be described again here to avoid repetition.

[0162] Example 4

[0163] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the robot control method provided in Example 1 is implemented.

[0164] In this embodiment, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0165] The computer-readable storage medium provided in this embodiment can implement the robot control method provided in Example 1, and will not be described again here to avoid repetition.

[0166] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or terminal comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or terminal comprising the element.

[0167] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0168] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A robot control method, characterized in that: The method comprises: Construct a two-wheeled inverted pendulum model based on a wheel-legged robot; Constructing an initial state space equation according to the two-wheel inverted pendulum model; Linearizing the initial state-space equation to obtain a state-space equation of a linear steady-state system; Obtaining a quadratic performance objective function based on a state-space equation of the linear time-invariant system; Calculating the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torque; Performing forward kinematic analysis on the planar five-bar mechanism of the legs of the wheel-legged robot to obtain a set of foot endpoint equations of the wheel-legged robot; Obtaining a foot endpoint vector expression according to the foot endpoint equation group; Obtaining a velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression; Determining a mapping relationship between the velocity Jacobian matrix, the hip joint driving torque vector, and the two-dimensional contact force exerted on the foot endpoint according to the principle of virtual work; Adding a virtual spring damper to the wheel-leg robot to construct a feedback control framework; The hip joint driving torque of the wheel-legged robot is obtained based on the feedback control framework and the mapping relationship, and the wheel-legged robot is controlled according to the hip joint driving torque.

2. The method according to claim 1, characterized in that The controlling the wheel-legged robot according to the wheel torque comprises: Using the wheel torque as a control instruction, and inputting the control instruction into the wheel motor of the wheel-legged robot; The wheel motor is controlled according to the control instruction to output a torque equal to the wheel torque.

3. The method according to claim 1, characterized in that The method further comprises: After the wheel motor outputs a torque equal to the wheel torque, multiple actual state quantities of the wheel-legged robot are obtained.

4. The method according to claim 1, wherein The obtaining of the hip joint driving torque of the wheel-leg robot based on the feedback control framework and the mapping relationship includes: calculating the two-dimensional contact force based on the feedback control framework; The hip joint driving torque is calculated based on the calculated two-dimensional contact force and the mapping relationship.

5. The method according to claim 4, characterized in that The virtual spring damper is added to the wheel-leg robot to construct a feedback control framework, including: Virtual spring dampers are added in the first direction, the second direction of the foot end of the wheel-legged robot and the rolling direction of the wheel-legged robot to construct a three-channel feedback control framework.

6. The method according to claim 1, characterized in that The method of obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression includes: Performing total differential processing on the foot endpoint vector expression to obtain a total differential expression; The velocity Jacobian matrix is ​​determined according to the total differential expression.

7. A robot control device, characterized in that: The device comprises: The first building module is used to build a two-wheeled inverted pendulum model based on the wheel-legged robot; A second building module is used to build an initial state space equation according to the two-wheel inverted pendulum model; a processing module, configured to linearize the initial state-space equation to obtain a state-space equation of a linear steady-state system; An acquisition module, configured to acquire a quadratic performance objective function according to a state space equation of the linear time-invariant system; a control module, configured to calculate the quadratic performance objective function through a linear quadratic regulator to obtain the wheel torque of the wheel-legged robot, and control the wheel-legged robot according to the wheel torque; Performing forward kinematic analysis on the planar five-bar mechanism of the legs of the wheel-legged robot to obtain a set of foot endpoint equations of the wheel-legged robot; Obtaining a foot endpoint vector expression according to the foot endpoint equation group; Obtaining a velocity Jacobian matrix of the leg parallel structure of the wheel-leg robot according to the foot endpoint vector expression; Determining a mapping relationship between the velocity Jacobian matrix, the hip joint driving torque vector, and the two-dimensional contact force exerted on the foot endpoint according to the principle of virtual work; Adding a virtual spring damper to the wheel-leg robot to construct a feedback control framework; The hip joint driving torque of the wheel-legged robot is obtained based on the feedback control framework and the mapping relationship, and the wheel-legged robot is controlled according to the hip joint driving torque.

8. A robot, characterized in that: The robot control method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the robot control method according to any one of claims 1 to 6 is executed.

9. A computer-readable storage medium, characterized in that The robot control device stores a computer program, which executes the robot control method according to any one of claims 1 to 6 when running on a processor.

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