A force-position hybrid control method for aerial working robots based on switching strategy

Abstract

The present invention relates to the field of robot control technology, specifically to a force-position hybrid control method for an aerial work robot based on a switching strategy, comprising: 1. constructing an aerial work robot system, and performing dynamic modeling analysis on it to obtain a dynamic model of the aerial work robot; 2. defining position tracking error and position sliding mode variables, and designing an additional force estimator; 3. designing a position loop control force; 4. designing a force / position hybrid control strategy under a contact state; 5. designing an additional torque estimator and a geometric attitude controller; 6. establishing a force / position hybrid control strategy under a free flight state and a contact state, and realizing detection and control of force-position hybrid interactive contact between the aerial work robot and the environment based on the position loop control force, the attitude controller and the force / position hybrid control strategy. The method of the present invention can ensure the overall stability and precise force interaction capability of the aerial work robot system without force / torque measurement information.

Description

Technical Field

[0001] The present invention relates to the field of robot control technology, and in particular to a force-position hybrid control method of an aerial working robot based on a switching strategy. Background Art

[0002] Early inspection and maintenance of industrial infrastructure mainly relied on manual work or large-scale automated equipment, which had problems such as difficult operation and maintenance, great hidden dangers, high costs, and low efficiency. With the rapid development of aerial robot technology, the demand for aerial robots to perform industrial contact detection has been increasing in recent years. This new type of aerial robot is usually called an aerial work robot. For aerial contact interaction detection tasks, aerial work robots usually need to track the required force while sliding. In order to meet the needs of aerial work robots for infrastructure inspection and maintenance tasks, it is urgent to develop the ability to detect sliding contact between aerial work robots and the environment. Summary of the invention

[0003] The present invention provides a force-position hybrid control method for an aerial working robot based on a switching strategy, so as to solve the technical problem in the prior art that the aerial working robot has insufficient detection capability of sliding contact with the environment.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] The present invention provides a force-position hybrid control method for an aerial working robot based on a switching strategy, comprising the following steps:

[0006] Step S1, constructing an aerial working robot system that actively interacts with the environment, and performing dynamic modeling analysis on the aerial working robot system to obtain a dynamic model of the aerial working robot;

[0007] Step S2, defining a position tracking error and a position sliding mode variable, and designing an additional force estimator according to the dynamic model, the position tracking error and the position sliding mode variable;

[0008] Step S3, introducing an obstacle function, and designing the position loop control force in a free flight state according to the additional force estimator and the obstacle function;

[0009] Step S4, designing a force / position hybrid control strategy under contact state;

[0010] Step S5, designing an extra torque estimator, and designing a geometric attitude controller based on the extra torque estimator;

[0011] Step S6: Establish a force / position hybrid control strategy in free flight and contact state, and realize the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment based on the position loop control force, attitude controller and force / position hybrid control strategy.

[0012] Furthermore, the step S1 specifically comprises the following steps:

[0013] Step S11, constructing an aerial work robot system for active contact detection with the environment, wherein the aerial work robot interaction system includes a quad-rotor drone and a rigidly mounted contact tool;

[0014] Step S12: Using the Newton-Euler equation method, a dynamic model of the aerial working robot is constructed as follows:

[0015]

[0016] in, represents position acceleration, u represents the position loop control force, S(·) is recorded as a skew-symmetric matrix operator, which is defined as Satisfies S(a)b=a×b, Represents an entity set, and the symbol “×” represents a cross product; and are the total mass and inertia matrix of the aerial work robot, Denote the angular velocity vector in the body coordinate system, R b ∈SO(3) is the transfer matrix from the world coordinate system to the body coordinate system, g is the gravity constant, e 3 =[0,0,1] T ; and are the total lift and moment, respectively, and f e and They represent the additional interaction force in the world coordinate system and the interaction torque in the body coordinate system, Represents the rotation matrix R b The differential of .

[0017] Furthermore, the contact tool in step S11 is installed on the quadrotor drone, and the quadrotor drone contacts an external contact object through the contact tool;

[0018] The quadrotor drone is equipped with an airborne Pixhawk open source flight control system, which includes an airborne inertial measurement unit, and an external position sensor and an external linear velocity sensor are both installed on the airborne Pixhawk open source flight control system;

[0019] Among them, the external position sensor is used to obtain the position signal of the quadrotor drone;

[0020] The external linear velocity sensor is used to obtain the linear velocity signal of the quadrotor drone;

[0021] The onboard inertial measurement unit is used to obtain the attitude signal and angular velocity signal of the quadrotor drone.

[0022] Furthermore, the step S2 specifically comprises the following steps:

[0023] Step S21, define the position tracking error as:

[0024] e p =pp d (3)

[0025] Among them, p d is the desired position trajectory, p represents the position trajectory;

[0026] Step S22: construct the position sliding mode variable according to the position tracking error:

[0027]

[0028] in, Indicates linear velocity error; Λ=diag{Λ 1 ,Λ 2 ,Λ 3} is a positive definite diagonal matrix;

[0029] Step S23: According to the position error and the sliding mode variable, an additional force estimator is designed as:

[0030]

[0031] Where γ is the positive gain, is the additional force f e , ζ is an intermediate variable of the force estimator, represents the differential of the intermediate variable of the force estimator; represents the desired linear acceleration.

[0032] Furthermore, the step S3 specifically comprises the following steps:

[0033] Step S31: Introduce a positive parameter constraining the maximum position error in represents the set of positive real numbers, and defines the predefined position boundary properties as:

[0034] -ρ i <e p,i <ρ i ,i=1,2,3 (6)

[0035] Among them, e p,i is the position error e p The i-th element of ;

[0036] Step S32: introducing the barrier function:

[0037]

[0038] Among them, δ is a positive constant;

[0039] Step S33: According to the additional force estimator and the obstacle function of formula (7), the position loop control force in the free flight state is designed to be:

[0040]

[0041] in, is a positive definite matrix, is a diagonal matrix.

[0042] Furthermore, the step S4 specifically comprises the following steps:

[0043] Step S41: When contact occurs, a scaled expected position trajectory is defined in the x direction as:

[0044]

[0045] Among them, x r and x d are the reference trajectory and the expected trajectory in the x direction, is an estimate of the scaling factor α.

[0046] Step S42: Design the adaptive rate of the scale factor to be:

[0047]

[0048] in, is the force error in the x direction, represents the differential of the force error; and is the additional force and desired force in the x direction, θ is a positive constant, δ k and are all normal numbers;

[0049] Step S43: In order to achieve the desired force adjustment, according to equations (9) and (10), the force / position hybrid control strategy under the contact state is designed as follows:

[0050]

[0051] Among them, k p and k d is a mean normal number and satisfies the following relationship: and represents the linear velocity of the aerial work robot in the x direction, represents the desired force in the x direction.

[0052] Furthermore, the step S5 specifically comprises the following steps:

[0053] Step S51: Based on the generalized momentum method, an additional torque estimator is designed as:

[0054]

[0055] in, is the additional torque τ b The estimated value of is a positive definite diagonal matrix;

[0056] Step S52: Calculate the desired posture of the aerial working robot according to the position loop control force u in equation (8): for:

[0057]

[0058] Among them, r 1,d , r 2,d , r 3,d Represent three different desired postures, where ψ d is the desired yaw angle; ||.|| represents the Euclidean norm of.

[0059] Step S53: Given the desired posture R of the aerial working robot b,d and the desired angular velocity Defining the posture tracking error and angular velocity error for:

[0060]

[0061] The symbol “∨” represents the inverse operation of the skew-symmetric matrix operator S(·);

[0062] Step S54: According to equations (13), (15) and (16), a geometric attitude controller based on a torque estimator is designed.

[0063] Furthermore, the geometric posture controller in step S54 is:

[0064]

[0065] Among them, K R and are all positive constant gain matrices; represents the differential of the desired angular velocity.

[0066] Furthermore, the step S6 specifically comprises the following steps:

[0067] Step S61, defining a force / position hybrid control strategy in free flight and contact state;

[0068] Step S62: Based on the position loop control force of formula (8), the attitude controller of formula (17) and the force / position hybrid control strategy, the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment is realized.

[0069] Furthermore, the force / position hybrid control strategy in the free flight and contact state in step S61 is:

[0070]

[0071] in, represents the expected linear acceleration in the x direction; Indicates the linear velocity error in the x direction; e x Indicates the position error in the x direction; represents the estimated force in the x-direction; Represents the estimated error value of α; when x t <x e When x t ≥x e When the aerial work robot is in contact state, it adopts a force / position hybrid control strategy.

[0072] Beneficial effects of the present invention:

[0073] 1) The present invention proposes a force-position hybrid control method based on a switching strategy, which can ensure the overall stability and precise force interaction capability of the aerial work robot system. Compared with the existing scheme, the additional force / torque estimator does not use additional force sensors and acceleration signals.

[0074] 2) The present invention introduces an obstacle function and designs a robust position loop control force based on force estimation in free flight state, which can ensure that the position tracking error is within a predefined boundary range.

[0075] 3) The present invention proposes a force / position hybrid control strategy under contact state, which uses an adaptive mechanism to update the proportional factor of the desired position trajectory, thereby achieving the desired contact force adjustment.

[0076] 4) The present invention proposes a force / position hybrid control strategy in free flight state and contact state, which ensures the steady-state behavior of the aerial work robot system in the transition from free flight to contact and separation in contact mode, and can ensure the smooth completion of the force-position hybrid interactive contact detection task of the aerial work robot system. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 is a flow chart of the present invention;

[0078] Figure 2 It is a schematic diagram of a model of the present invention;

[0079] Figure 3 It is a block diagram of the algorithm of the present invention;

[0080] Figure 4 It is the xyz direction position tracking trajectory diagram of the present invention in simulation;

[0081] Figure 5 It is a posture tracking trajectory diagram of the present invention in simulation;

[0082] Figure 6 A schematic diagram of the position tracking error in the xyz direction with predefined performance in the simulation of the present invention;

[0083] Figure 7 A schematic diagram of the posture tracking error of the present invention having predefined performance in simulation;

[0084] Figure 8 It is a schematic diagram of the force tracking trajectory in the simulation of the present invention;

[0085] Fig. 9 It is a schematic diagram of the yz plane trajectory in the simulation of the present invention. DETAILED DESCRIPTION

[0086] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0087] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0088] Reference Figure 1 The embodiment of the present application provides a force-position hybrid control method of an aerial working robot based on a switching strategy, comprising the following steps:

[0089] Step S1, constructing an aerial working robot system that actively interacts with the environment, and performing dynamic modeling analysis on the aerial working robot system to obtain a dynamic model of the aerial working robot;

[0090] Step S2, defining a position tracking error and a position sliding mode variable, and designing an additional force estimator according to the dynamic model, the position tracking error and the position sliding mode variable;

[0091] Step S3, introducing an obstacle function, and designing the position loop control force in a free flight state according to the additional force estimator and the obstacle function;

[0092] Step S4, designing a force / position hybrid control strategy under contact state;

[0093] Step S5, designing an extra torque estimator, and designing a geometric attitude controller based on the extra torque estimator;

[0094] Step S6: Establish a force / position hybrid control strategy in free flight and contact state, and realize the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment based on the position loop control force, attitude controller and force / position hybrid control strategy.

[0095] The present invention proposes a force-position hybrid control method based on a switching strategy, which can ensure the overall stability and precise force interaction capability of the aerial work robot system. Compared with the existing scheme, the additional force / torque estimator does not use additional force sensors and acceleration signals.

[0096] The specific implementation method of each step is further explained below.

[0097] Step S1, constructing an aerial working robot system that actively interacts with the environment, and performing dynamic modeling analysis on the aerial working robot system to obtain a dynamic model of the aerial working robot;

[0098] In this embodiment, step S1 specifically includes the following steps:

[0099] Step S11, constructing an aerial work robot system for active contact detection with the environment, wherein the aerial work robot interaction system includes a quad-rotor drone and a rigidly mounted contact tool;

[0100] Step S12: Using the Newton-Euler equation method, a dynamic model of the aerial working robot is constructed as follows:

[0101]

[0102] in, represents position acceleration, u represents the position loop control force, S(·) is recorded as a skew-symmetric matrix operator, which is defined as Satisfies S(a)b=a×b, Represents an entity set, and the symbol “×” represents a cross product; and are the total mass and inertia matrix of the aerial work robot, Denote the angular velocity vector in the body coordinate system, R b∈SO(3) is the transfer matrix from the world coordinate system to the body coordinate system, g is the gravity constant, e 3 =[0,0,1] T ; and are the total lift and moment, respectively, and f e and They represent the additional interaction force in the world coordinate system and the interaction torque in the body coordinate system, Represents the rotation matrix R b The differential of .

[0103] In this embodiment, the contact tool in step S11 is installed on the quad-rotor drone, and the quad-rotor drone contacts an external contact object through the contact tool;

[0104] The quadrotor drone is equipped with an airborne Pixhawk open source flight control system, which includes an airborne inertial measurement unit, and an external position sensor and an external linear velocity sensor are both installed on the airborne Pixhawk open source flight control system;

[0105] Among them, the external position sensor is used to obtain the position signal of the quadrotor drone;

[0106] The external linear velocity sensor is used to obtain the linear velocity signal of the quadrotor drone;

[0107] The airborne inertial measurement unit is used to obtain the attitude signal and angular velocity signal of the quadrotor drone. The airborne inertial measurement unit includes a three-axis gyroscope, a three-axis accelerometer, a three-axis magnetometer and a barometer sensor. The barometer sensor is used to obtain the altitude information of the quadrotor drone.

[0108] Step S2, defining a position tracking error and a position sliding mode variable, and designing an additional force estimator according to the dynamic model, the position tracking error and the position sliding mode variable;

[0109] In this embodiment, step S2 specifically includes the following steps:

[0110] Step S21, define the position tracking error as:

[0111] e p =pp d (3)

[0112] Among them, p d is the desired position trajectory, p represents the position trajectory;

[0113] Step S22: construct the position sliding mode variable according to the position tracking error:

[0114]

[0115] in, Indicates linear velocity error; Λ=diag{Λ 1 ,Λ 2 ,Λ 3} is a positive definite diagonal matrix;

[0116] Step S23: According to the position error and the sliding mode variable, an additional force estimator is designed as:

[0117]

[0118] Where γ is the positive gain, is the additional force f e , ζ is an intermediate variable of the force estimator, represents the differential of the intermediate variable of the force estimator; represents the desired linear acceleration.

[0119] Step S3, introducing an obstacle function, and designing the position loop control force in a free flight state according to the obstacle function;

[0120] In this embodiment, step S3 specifically includes the following steps:

[0121] Step S31: Introduce a positive parameter constraining the maximum position error in represents the set of positive real numbers, and defines the predefined position boundary properties as:

[0122] -ρ i <e p,i <ρ i ,i=1,2,3 (6)

[0123] Among them, e p,i is the position error e p The i-th element of ;

[0124] Step S32: introducing the barrier function:

[0125]

[0126] Among them, δ is a positive constant;

[0127] Step S33: According to the additional force estimator and the obstacle function of formula (7), the position loop control force in the free flight state is designed. The position loop input force of the position loop control force is:

[0128]

[0129] in, is a positive definite matrix, is a diagonal matrix.

[0130] Step S4, designing a force / position hybrid control strategy under contact state;

[0131] In this embodiment, step S4 specifically includes the following steps:

[0132] Step S41: When contact occurs, a scaled expected position trajectory is defined in the x direction as:

[0133]

[0134] Among them, x r and x d are the reference trajectory and the expected trajectory in the x direction, is an estimate of the scaling factor α.

[0135] Step S42: Design the adaptive rate of the scale factor to be:

[0136]

[0137] in,

[0138] in, is the force error in the x direction, represents the differential of the force error; and is the additional force and desired force in the x direction, θ is a positive constant, δ k and are all normal numbers;

[0139] Step S43: In order to achieve the desired force adjustment, according to equations (9) and (10), the force / position hybrid control strategy under the contact state is designed as follows:

[0140]

[0141] Among them, k p and k d are all positive numbers and satisfy the following relationship: and represents the linear velocity of the aerial work robot in the x direction, represents the desired force in the x direction.

[0142] Step S5, designing an extra torque estimator, and designing a geometric attitude controller based on the extra torque estimator;

[0143] In this embodiment, step S5 specifically includes the following steps:

[0144] Step S51: Based on the generalized momentum method, an additional torque estimator is designed as:

[0145]

[0146] in, is the additional torque τ b The estimated value of is a positive definite diagonal matrix;

[0147] Step S52: Calculate the desired posture of the aerial working robot according to the position loop control force u in equation (8): for:

[0148]

[0149] Among them, r 1,d , r 2,d , r 3,d Represent three different desired postures, where ψ d is the desired yaw angle; ||.|| represents the Euclidean norm of.

[0150] Step S53: Given the desired posture R of the aerial working robot b,d and the desired angular velocity Defining the posture tracking error and angular velocity error for:

[0151]

[0152] The symbol “∨” represents the inverse operation of the skew-symmetric matrix operator S(·);

[0153] Step S54: According to equations (13), (15) and (16), a geometric attitude controller based on a torque estimator is designed.

[0154] In this embodiment, the geometric posture controller in step S54 is:

[0155]

[0156] Among them, K R and are all positive constant gain matrices; represents the differential of the desired angular velocity.

[0157] Step S6, define the force / position hybrid control strategy in free flight and contact state, and realize the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment based on the position loop control force, attitude controller, free flight state and contact state.

[0158] In this embodiment, step S6 specifically includes the following steps:

[0159] Step S61, establishing a force / position hybrid control strategy in free flight and contact state;

[0160] Step S62: Based on the position loop control force of formula (8), the attitude controller of formula (17) and the force / position hybrid control strategy in step S61, the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment is realized.

[0161] In this embodiment, the force / position hybrid control strategy in step S61 is:

[0162]

[0163] in, represents the expected linear acceleration in the x direction; Indicates the linear velocity error in the x direction; e x Indicates the position error in the x direction; represents the estimated force in the x-direction; Represents the estimated error value of α, when x t <x e When x t ≥x e When the aerial work robot is in contact state, it adopts a force / position hybrid control strategy.

[0164] In the present invention, the quadcopter is equipped with a rigidly connected tool. The position and linear velocity signals are measured by external sensors, and the attitude and angular velocity signals are obtained from the onboard inertial measurement unit. The parameters of the aerial work robot are set as follows: m = 2.48 kg, J = diag (0.0756, 0.0789, 0.1277) kg·m 2 , g = 9.81 kg·m / s 2; the position loop control force parameters are set to: Λ = diag (5.0, 5.0, 5.5), K s =diag(2.7,3.4,2.5), δ=0.0003, ρ 1 =ρ 2 =ρ 3 =0.15; the force / position hybrid control strategy parameters under contact state are set to: k p =8.5, k d =18.6,θ=10 -5 , At contact, the desired force in the x direction is set to The environmental stiffness is set to k e =1000N / m; attitude controller parameter is set to K R= diag(3.37, 4.37, 4.37) and K ω = diag(0.12, 0.48, 0.48), where the desired yaw angle ψ d is always zero; the parameter gains of the additional force estimator and the moment estimator are set to: γ = 4.8 and K I = diag(5.2, 5.2, 5.2), where the initial value of the variable ζ is set to ζ(0) = 0 3×1 .

[0165] As Figure 4-8 shown Figure 4 is the xyz-direction position tracking trajectory diagram of the aerial operation robot according to the embodiment of the present invention in simulation, Figure 5 is the attitude tracking trajectory diagram of the aerial operation robot according to the embodiment of the present invention in simulation. It can be seen that the aerial operation robot has good convergence speed and tracking accuracy; Figure 6 is the schematic diagram of the xyz-direction position tracking error with a safety boundary of the aerial operation robot according to the embodiment of the present invention in simulation. The position states are all within the predefined safety boundary range; Figure 7 is the schematic diagram of the attitude tracking error of the aerial operation robot according to the embodiment of the present invention in simulation; Figure 8 is the schematic diagram of the force tracking trajectory of the aerial operation robot according to the embodiment of the present invention in simulation. It can be obtained that the estimated value of the additional force after low-pass filtering has a good estimation effect on the required contact force, so as to complete the task of detecting the hybrid sliding contact of the environmental force and position; Fig. 9 is the schematic diagram of the yz-plane trajectory of the aerial operation robot according to the embodiment of the present invention in simulation.

[0166] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention. Moreover, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that those skilled in the art can implement it. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described above.

Claims

1. A force-position hybrid control method for aerial working robots based on switching strategy. It is characterized in that The steps include: Step S1, constructing an aerial working robot system that actively interacts with the environment, and performing dynamic modeling analysis on the aerial working robot system to obtain a dynamic model of the aerial working robot; Step S2, defining a position tracking error and a position sliding mode variable, and designing an additional force estimator according to the dynamic model, the position tracking error and the position sliding mode variable; Step S3, introducing an obstacle function, and designing the position loop control force in a free flight state according to the additional force estimator and the obstacle function; Step S4, designing a force / position hybrid control strategy under contact state; Step S5, designing an extra torque estimator, and designing a geometric attitude controller based on the extra torque estimator; Step S6: Establish a force / position hybrid control strategy in the free flight state and the contact state, and based on the position loop control force, attitude controller and force / position hybrid control strategy, realize the detection and control of the force-position hybrid interactive contact between the aerial working robot and the environment.

2. The force-position hybrid control method for an aerial work robot according to claim 1, It is characterized in that The step S1 specifically comprises the following steps: Step S11, constructing an aerial working robot system for active contact detection with the environment, wherein the aerial working robot interaction system includes a quad-rotor drone and a contact tool; Step S12: Using the Newton-Euler equation method, a dynamic model of the aerial working robot is constructed as follows: in, represents position acceleration, u represents the position loop control force, S(·) is recorded as a skew-symmetric matrix operator, which is defined as Satisfies S(a)b=a×b, Represents an entity set, and the symbol "×" represents a cross product; and are the total mass and inertia matrix of the aerial work robot, Denote the angular velocity vector in the body coordinate system, R b ∈SO(3) is the transfer matrix from the world coordinate system to the body coordinate system, g is the gravity constant, e 3 =[0,0,1] T ; and are the total lift and moment, respectively, and f e and They represent the additional interaction force in the world coordinate system and the interaction torque in the body coordinate system, Represents the rotation matrix R b The differential of .

3. The force-position hybrid control method for an aerial work robot according to claim 2, It is characterized in that The contact tool in step S11 is installed on the quadrotor drone, and the quadrotor drone contacts an external contact object through the contact tool; The quadrotor drone is equipped with an airborne Pixhawk open source flight control system, which includes an airborne inertial measurement unit, and an external position sensor and an external linear velocity sensor are both installed on the airborne Pixhawk open source flight control system; Among them, the external position sensor is used to obtain the position signal of the quadrotor drone; The external linear velocity sensor is used to obtain the linear velocity signal of the quadrotor drone; The onboard inertial measurement unit is used to obtain the attitude signal and angular velocity signal of the quadrotor drone.

4. The force-position hybrid control method for an aerial work robot according to claim 2, It is characterized in that The step S2 specifically comprises the following steps: Step S21, define the position tracking error as: e p =p-p d (3) Among them, p d is the desired position trajectory, p represents the position trajectory; Step S22: construct the position sliding mode variable according to the position tracking error: in, Indicates linear velocity error; Λ=diag{Λ 1 ,Λ 2 ,Λ 3 } is a positive definite diagonal matrix; Step S23: According to the position error and the sliding mode variable, an additional force estimator is designed as: Where γ is the positive gain, is the additional force f e , ζ is an intermediate variable of the force estimator, represents the differential of the intermediate variable of the force estimator; represents the desired linear acceleration.

5. The force-position hybrid control method for an aerial work robot according to claim 4, It is characterized in that The step S3 specifically comprises the following steps: Step S31: Introduce a positive parameter constraining the maximum position error in represents the set of positive real numbers, and defines the predefined position boundary properties as: -r i <e p,i <p i ,i=1,2,3 (6) Among them, e p,i is the position error e p The i-th element of ; Step S32: introducing the barrier function: Among them, δ is a positive constant; Step S33: According to the additional force estimator and the obstacle function of formula (7), the position loop control force in the free flight state is designed to be: in, is a positive definite matrix, is a diagonal matrix.

6. The force-position hybrid control method for an aerial work robot according to claim 5, It is characterized in that The step S4 specifically comprises the following steps: Step S41: When contact occurs, a scaled expected position trajectory is defined in the x direction as: Among them, x r and x d are the reference trajectory and the expected trajectory in the x direction, is an estimate of the scaling factor α; Step S42: Design the adaptive rate of the scale factor to be: in, is the force error in the x direction, represents the differential of the force error; and are the additional force and desired force in the x direction, θ is a positive constant, is a positive constant; Step S43: In order to achieve the desired force adjustment, according to equations (9) and (10), the force / position hybrid control strategy under the contact state is designed as follows: Among them, k p and k d is a mean normal number and satisfies the following relationship: and represents the linear velocity of the aerial work robot in the x direction, represents the desired force in the x direction.

7. The force-position hybrid control method for an aerial working robot according to claim 6, It is characterized in that The step S5 specifically comprises the following steps: Step S51: Based on the generalized momentum method, an additional torque estimator is designed as: in, is the additional torque τ b The estimated value of is a positive definite diagonal matrix; Step S52: Calculate the desired posture of the aerial working robot according to the position loop control force u in equation (8): for: Among them, r 1,d , r 2,d , r 3,d Represent three different desired postures, where ψ d is the desired yaw angle; ||.|| represents the Euclidean norm of. Step S53: Given the desired posture R of the aerial working robot b,d and the desired angular velocity Defining the posture tracking error and angular velocity error for: The symbol "∨" represents the inverse operation of the skew-symmetric matrix operator S(·); Step S54: According to equations (13), (15) and (16), a geometric attitude controller based on a torque estimator is designed.

8. The force-position hybrid control method for an aerial work robot according to claim 7, It is characterized in that The geometric posture controller in step S54 is: Among them, K R and are all positive constant gain matrices; represents the differential of the desired angular velocity.

9. The force-position hybrid control method for an aerial work robot according to claim 8, It is characterized in that The step S6 specifically comprises the following steps: Step S61, establishing a force / position hybrid control strategy in free flight and contact state; Step S62: Based on the position loop control force of formula (8), the attitude controller of formula (17) and the force / position hybrid control strategy, the detection and control of the force / position hybrid interactive contact between the aerial working robot and the environment is realized.

10. The force-position hybrid control method for an aerial work robot according to claim 9, It is characterized in that The force / position hybrid control strategy in the free flight state and the contact state in step S61 is: in, represents the expected linear acceleration in the x direction; Indicates the linear velocity error in the x direction; e x Indicates the position error in the x direction; represents the estimated force in the x-direction; Represents the estimated error value of α; when x t <x e When x t ≥x e When the aerial work robot is in contact state, it adopts a force / position hybrid control strategy.

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