Massage control system construction method, massage control method and massage physiotherapy robot

Abstract

The invention discloses a massage control system construction method, a massage control method and a massage physiotherapy robot wherein the massage control system construction method comprises the following steps: defining a control rate 1 suitable for equality constraints; defining a control rate 2 suitable for inequality constraints; defining a control rate 3 simultaneously applicable to the equality constraint and the inequality constraint; based on the first control rate, the second control rate and the third control rate, a simplified external environment impedance control model is constructed in combination with Cartesian impedance control; providing a motion trail generator, generating an environment motion trail of the external environment impedance control model in real time, and taking the environment motion trail as the input of the external environment impedance control model. According to the invention, the control rate I, the control rate II and the control rate III ensure the continuous stability, comfort, adaptability and safety of the massage process; and meanwhile, by combining Cartesian impedance control, the optimal massage path can be planned in real time according to the external environment of the back of the human body, and meanwhile the optimal massage torque is output.

Description

Technical Field

[0001] The present invention relates to the technical field of massage robots, and in particular to a massage control system construction method, a massage control method and a massage therapy robot. Background Art

[0002] Traditional Chinese massage has a long history. In ancient times, China had massage medical activities. When people at that time encountered injuries and pain during work, they instinctively massaged the painful area with hands, and they would feel the pain relieved or disappeared. After long-term practice, the ancients realized the role of massage, and it became a conscious medical activity, and then gradually developed into the discipline of massage in traditional Chinese medicine. The benefits of traditional Chinese massage include reducing muscle tension, pain, stress, anxiety, depression, and improving sleep quality. The following eight common massage techniques can be selected for traditional Chinese massage: pressing, rubbing, pushing, holding, kneading, pinching, shaking, and hitting. With the continuous advancement of science and technology in recent years, the service massage robot industry has also developed rapidly. For example, the popular smart massage chair in the prior art allows users to easily adjust the massage intensity and frequency through the control panel. Although it has a certain massage experience, the massage techniques that can be achieved by the smart massage chair are relatively single, and usually can only achieve functions such as pressing and pushing alone; in addition, the smart massage chair cannot fit the human body curve well during the massage process. The massage drive may sometimes not contact the human body surface, and sometimes may over-press the human body surface, making it difficult to respond well to fit the human body curve, and the massage effect needs to be improved.

[0003] For example, the invention patent application with application publication number CN118372263A discloses a control method, a control device and a massage robot for a massage robot. This technical solution obtains the height value of each point of the preset trajectory of the massage head through a depth camera; obtains the actual pressing force value of the massage head at the current point through a force sensor; uses the height value of each point as a feedforward input, and performs feedback control of the robot arm based on the actual pressing force value and the set pressing force value of the current point. The above embodiment uses the height value of each point of the trajectory obtained by the depth camera as a feedforward input, combined with feedback control for force control, which can make the end of the robot fit the human body better, respond to ups and downs in a timely manner, have a smaller massage force error, and a better massage effect. However, this technical solution still cannot realize a variety of massage techniques in traditional Chinese massage. Summary of the invention

[0004] The purpose of the present invention is to provide a massage control system construction method, a massage control method and a massage therapy robot to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The method for constructing a massage control system comprises the following steps:

[0007] A control rate u1 applicable to the equality constraint is defined to obtain the required pressure applied by the massage mechanism on the human body surface and to keep the end force direction of the massage mechanism perpendicular to the human body surface;

[0008] A control rate u2 applicable to the inequality constraint is defined to control the end position of the massage mechanism so as to adapt it to the unknown features existing on the surface of the human body;

[0009] A control rate u3 applicable to both equality constraints and inequality constraints is defined to handle the instability of the control system caused by sudden changes in the end position and end speed during the movement of the massage mechanism;

[0010] Based on control rate 1 u1, control rate 2 u2 and control rate 3 u3, combined with Cartesian impedance control, a simplified external environment impedance control model is constructed, and the external environment impedance control model is used to generate the output torque of the joint;

[0011] A motion trajectory generator is proposed. It combines the actual operation trajectory and planned operation trajectory of the massage mechanism to generate the environmental operation trajectory of the external environmental impedance control model in real time and uses it as the input of the external environmental impedance control model.

[0012] As a further solution of the present invention, the expression of the control rate-u1 variable structure control is:

[0013]

[0014] Among them, φ eq is a function that contains all equality constraints φ eq,i Column vector, scalar Indicates that in the direction of the vector field f eq,i Lie derivative of (x), row vector Represents a set of vector fields g in the direction φ eq,i Lie derivative of (x), column vector L f φ eq Contains all equality constraints L f φ eq,i , the matrix L g φ eq The row vector L containing all the equality constraints g φ eq,i , sign(·) represents the sign function, positive scalar represents the switching gain, which can be constant or time-varying, W eq represents the diagonal matrix for switching gain weights under constraints, ‖·‖1 represents the 1-norm, and the function diag min (·) Computes the minimum value of the diagonal elements of a matrix.

[0015] As a further solution of the present invention, the expression of the control rate u2 variable structure control is:

[0016]

[0017] Among them, the function v2dm(·) converts the vector into a diagonal matrix, the function pos(·) represents a positive function, that is, when x<0, pos(x) is equal to 0, when x>0, pos(x) is equal to 1, φ in is a column vector containing all inequality constraint functions φ in,i , the matrix L g φ in The row vector L containing all inequality constraints g φ in,i , scalar represents the direction of the vector field f in,i Lie derivative of (x), row vector. Represents a set of vector fields g in the direction φ in,i Lie derivative of (x), positive scalar is the switching gain, W in is a diagonal matrix representing the switching gain weights under inequality constraints, n a is the number of inequality constraints, i.e., in,i The number of constraints that are ≤0.

[0018] As a further solution of the present invention, the expression of the control rate u3 variable structure control is:

[0019]

[0020] in, + u + is the switching gain of the global sliding mode control, and its lower bound expression is:

[0021]

[0022] As a further solution of the present invention, a simplified external environment impedance control model adopts a mass-spring-damper system, and its expression is:

[0023]

[0024] Where M e is the quality coefficient, D e is the damping coefficient, K e is the spring constant, F ext is the external force in Cartesian space, for environmental location; The specific expression is:

[0025]

[0026] Among them, x0 is the planned position and x is the actual position;

[0027] The expression of the output torque τ in the joint space is:

[0028]

[0029] Where J is the Jacobian matrix of the manipulator, J T is the Jacobian matrix transpose of the manipulator, q is the generalized angle vector of the joint, M(q) is the inertia matrix, is the Coriolis force matrix, and G(q) is the gravity matrix.

[0030] As a further solution of the present invention, the environmental running trajectory generated by the motion trajectory generator is specifically divided into an acceleration stage, a uniform speed stage and a deceleration stage;

[0031] The acceleration phase constraint expression of the robot execution speed is:

[0032] if but

[0033] in, are the acceleration and deceleration parameters of the motion trajectory generator, is the actual speed, is the speed at the last sampling, x0 is the planned position, is the planned speed;

[0034] The uniform speed phase constraint expression of the robot execution speed is:

[0035] if but

[0036] in, The maximum speed of the motion trajectory generator.

[0037] The expression of the deceleration phase restriction condition of the robot execution speed is:

[0038] if but

[0039] in, is the distance from the current actual position x to the planned position x0.

[0040] A massage control method, a massage control system established based on a massage control system construction method, comprises the following steps:

[0041] Combining the actual operation trajectory and the planned operation trajectory of the massage mechanism, the environmental operation trajectory of the external environmental impedance control model is generated in real time, and is used as the input of the simplified external environmental impedance control model;

[0042] According to the environment running trajectory and the generalized motion trajectory of the joint, the output torque of the joint is generated, the joint motor action of the joint is controlled, and the corresponding massage action is performed;

[0043] The generalized motion trajectory of the joints is detected in real time and converted into the actual operation trajectory of the massage mechanism.

[0044] A massage therapy robot comprises a manipulator and a massage mechanism installed at the end of the manipulator, and a massage control system established based on a massage control system construction method, specifically comprising: a motion trajectory generator, used to combine an actual operation trajectory and a planned operation trajectory of the massage mechanism, and generate an environmental operation trajectory of an external environmental impedance control model in real time, and use it as an input of a simplified external environmental impedance control model;

[0045] A simplified external environment impedance control model, based on control rate one, control rate two and control rate three, combined with Cartesian impedance control, is used to generate the output torque of the joint according to the environmental operation trajectory and the generalized motion trajectory of the joint, control the joint motor action of the joint, and perform the corresponding massage action;

[0046] Sensors for detecting the joint generalized motion trajectory of the joint in real time;

[0047] The kinematic model, based on the generalized motion trajectory of the joints, is used to transform and generate the actual operation trajectory of the massage mechanism.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. The present invention obtains the required pressure exerted by the massage mechanism on the human body surface by controlling the rate 1, and keeps the force direction of the end actuator of the massage mechanism perpendicular to the human body surface, so as to ensure that the massage end actuator always fits the human body surface, and at the same time ensures that the entire massage process of the human body is continuous and stable;

[0050] 2. Control the end position of the massage mechanism through the control rate 2 to adapt it to the unknown features on the human body surface, ensuring that the massage posture of the massage end actuator can be adjusted in real time according to the features of the human back during the entire massage process, so as to increase the comfort and adaptability of the entire massage process;

[0051] 3. Through the three control rate processing, the instability of the control system caused by the sudden change of the position and speed of the end actuator during the movement of the massage mechanism is eliminated to ensure the safety of the entire massage process;

[0052] 4. The present invention also combines the above three control rates with Cartesian impedance control to construct a simplified external environment impedance control model, which is used to generate the output torque of the joint; the motion trajectory generator proposed in the present invention can combine the actual operation trajectory and the planned operation trajectory of the massage mechanism to generate the environmental operation trajectory of the external environment impedance control model in real time, and use it as the input of the external environment impedance control model. Through continuous iterative calculation, the optimal massage trajectory for each massage action is planned.

[0053] In summary, during the entire massage process, control rates one, two and three ensure the continuous stability, comfort, adaptability and safety of the massage process; at the same time, combined with Cartesian impedance control, the best massage path can be planned in real time according to the external environment of the human back, and the best massage torque can be output at the same time, ultimately realizing a variety of massage techniques in traditional Chinese medicine massage. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A flow chart of a method for constructing a massage control system;

[0055] Figure 2 This is a control diagram of the massage therapy robot;

[0056] Figure 3 It is a flowchart of the massage control method. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] See also Figures 1 to 3 , a massage control system construction method comprises the following steps:

[0059] A control rate of one applicable to the equality constraint is defined to obtain the required pressure applied by the massage mechanism on the surface of the human body and to keep the force applied by the end of the massage mechanism perpendicular to the surface of the human body;

[0060] A control rate 2 suitable for inequality constraints is defined to control the end position of the massage mechanism so as to adapt it to the unknown features existing on the surface of the human body;

[0061] A control rate 3 applicable to both equality constraints and inequality constraints is defined to handle the instability of the control system caused by sudden changes in the end position and end velocity during the movement of the massage mechanism;

[0062] Based on control rate 1, control rate 2 and control rate 3, combined with Cartesian impedance control, a simplified external environment impedance control model is constructed, and the simplified external environment impedance control model is used to generate the output torque of the joint;

[0063] A motion trajectory generator is proposed. It combines the actual operation trajectory and planned operation trajectory of the massage mechanism to generate the environmental operation trajectory of the external environmental impedance control model in real time, and uses it as the input of the simplified external environmental impedance control model.

[0064] As a specific solution of an embodiment of the present invention, the construction of the control rate u1 specifically includes:

[0065] First, consider a system with n x states and n u The dynamic system of the massage robot with input is expressed as:

[0066]

[0067] Among them, x(t) is the system state vector, d(t) is the system unmeasurable disturbance or model uncertainty, u(t) is the system control input vector, f is a vector field, and g is a set of vector fields;

[0068] On this basis, consider the equality constraint function of the system state vector x, which is expressed as:

[0069] φ eq,i (x)=0,i=1,…,N eq ;

[0070] Among them, φ eq,i (x) is the i-th equality constraint function; therefore, the region Φ of the state space that is constraint-compatible with the system state vector x is eq The expression is:

[0071] Φ eq ={x|φ eq,i (x)=0},i=1,…,N eq ;

[0072] Assume that the equality constraint function φ eq,i is differentiable, then the control rate of the following variable structure control is realized, which ensures that the system converges to the region Φ in a finite time: eq , and remains unchanged from now on, the expression of variable structure control is:

[0073]

[0074]

[0075] Among them, φeq is a function that contains all equality constraints φ eq,i Column vector, scalar Indicates that in the direction of the vector field f eq,i Lie derivative of (x), row vector Represents a set of vector fields g in the direction φ eq,i Lie derivative of (x), column vector L f φ eq Contains all equality constraints L f φ eq,i , the matrix L g φ eq The row vector L containing all the equality constraints g φ eq,i , sign(·) represents the sign function, positive scalar represents the switching gain, which can be constant or time-varying, W eq represents the diagonal matrix for switching gain weights under constraints, ‖·‖1 represents the 1-norm, and the function diag min (·) Computes the minimum value of the diagonal elements of a matrix.

[0076] As a specific solution of an embodiment of the present invention, the construction of the control rate u2 specifically includes:

[0077] Consider the given massage robot dynamic system And consider the inequality constraint function of the system state vector x, which is expressed as:

[0078] φ in,i (x)≤0,i=1,...,N;

[0079] Among them, φ in,i (x) represents the i-th inequality constraint function; therefore, the region Φ of the state space that is constraint-compatible with the system state vector x is in The expression is:

[0080] Φ in ={x|φ in,i (x)≤0},i=1,…,N in

[0081] Assume that the inequality constraint function φ in,i (x) is differentiable, then the control rate u2 of the following variable structure control is realized to ensure that the system converges to the region Φ in a finite time in , and remain stable from then on, the expression of variable structure control is:

[0082]

[0083] Among them, the function v2dm(·) converts the vector into a diagonal matrix, the function pos(·) represents a positive function, that is, when x<0, pos(x) is equal to 0, when x>0, pos(x) is equal to 1, φ in is a column vector containing all inequality constraint functions φ in,i , the matrix L g φ in The row vector L containing all inequality constraints g φ in,i , scalar represents the direction of the vector field f in,i Lie derivative of (x), row vector. Represents a set of vector fields g in the direction φ in,i Lie derivative of (x), positive scalar is the switching gain, W in is a diagonal matrix representing the switching gain weights under inequality constraints, n a is the number of inequality constraints, i.e., in,i The number of constraints that are ≤0.

[0084] As a specific solution of an embodiment of the present invention, the construction of the control rate u3 specifically includes:

[0085] Combining the above sliding mode control satisfying equality constraints (control rate one) and the sliding mode control satisfying inequality constraints (control rate two), consider the sliding mode control satisfying both equality constraints and inequality constraints, and its expression is:

[0086]

[0087] in, + u + is the switching gain of the global sliding mode control, and its lower bound expression is:

[0088]

[0089] As a specific solution of the embodiment of the present invention, the simplified external environment impedance control model adopts a mass-spring-damper system, and its expression is:

[0090]

[0091] Where M e is the quality coefficient, D e is the damping coefficient, K e is the spring constant, F ext is the external force in Cartesian space, for environmental location; The specific expression is:

[0092]

[0093] Among them, x0 is the planned position and x is the actual position.

[0094] The external force F in Cartesian space ext Transform from Cartesian space to joint space and use the Jacobian matrix transpose of the manipulator to obtain the external torque in the joint space, which is expressed as:

[0095] τ ext =J T F ext ;

[0096] Among them, τ ext is the external torque in the joint space, J T is the transposed Jacobian matrix of the manipulator.

[0097] The dynamic model of the manipulator is:

[0098]

[0099] Where q is the generalized angle vector of the joint, M(q) is the inertia matrix, is the Coriolis force matrix, G(q) is the gravity matrix, and τ is the output torque in the joint space.

[0100] From the above, the expression of output torque τ is:

[0101]

[0102] As a specific solution of an embodiment of the present invention, the environmental operation trajectory generated by the motion trajectory generator is used as the input of a simplified external environmental impedance control model to control the output torque of the manipulator joint. In the present invention, the environmental operation trajectory generated by the motion trajectory generator is specifically divided into three stages: acceleration, uniform speed, and deceleration. The acceleration stage is the initial stage of the environmental operation trajectory. In this stage, the manipulator execution speed of the massage therapy robot needs to be limited to prevent it from exceeding the maximum massage executable speed and losing control. The acceleration stage restriction condition expression of the manipulator execution speed is:

[0103] if but

[0104] in, are the acceleration and deceleration parameters of the motion trajectory generator, is the actual speed, is the speed at the last sampling, The planned speed.

[0105] After the initial stage of the environmental operation trajectory, the manipulator movement of the massage therapy robot enters the uniform speed stage. The uniform speed stage constraint expression of the manipulator execution speed is:

[0106] if but

[0107] in, The maximum speed of the motion trajectory generator.

[0108] Finally, when the actual position is close to the target position, the manipulator of the massage therapy robot enters the deceleration stage. The deceleration stage constraint expression of the manipulator execution speed is:

[0109] if but

[0110] in, is the distance from the current actual position x to the planned position x0.

[0111] The trajectory generator based on the above three constraints is used to adjust the movement speed of the manipulator of the massage therapy robot.

[0112] See also Figure 2-3 The present invention also proposes a massage control method, which is based on the massage control system established by the above-mentioned massage control system construction method, and includes the following steps:

[0113] Combining the actual operation trajectory and the planned operation trajectory of the massage mechanism, the environmental operation trajectory of the external environmental impedance control model is generated in real time, and is used as the input of the simplified external environmental impedance control model;

[0114] According to the environment running trajectory and the generalized motion trajectory of the joint, the output torque of the joint is generated, the joint motor action of the joint is controlled, and the corresponding massage action is performed;

[0115] The generalized motion trajectory of the joints is detected in real time and converted into the actual operation trajectory of the massage mechanism.

[0116] The present invention also provides a massage therapy robot, comprising a manipulator and a massage mechanism installed at the end of the manipulator, and a massage control system established based on the above-mentioned massage control system construction method, further comprising: a motion trajectory generator, used to combine the actual operation trajectory and the planned operation trajectory of the massage mechanism to generate the environment operation trajectory of the external environment impedance control model in real time, and use it as the input of the simplified external environment impedance control model;

[0117] A simplified external environment impedance control model, based on control rate one, control rate two and control rate three, combined with Cartesian impedance control, is used to generate the output torque of the joint according to the environmental operation trajectory and the generalized motion trajectory of the joint, control the joint motor action of the joint, and perform the corresponding massage action;

[0118] A sensor, specifically a joint encoder, is used to detect the joint generalized motion trajectory of the joint in real time;

[0119] The kinematic model, based on the generalized motion trajectory of the joints, is used to transform and generate the actual operation trajectory of the massage mechanism.

[0120] In the embodiment of the present invention, the control rate is applicable to the environmental position The equation constraints in the equation are modified to obtain the required pressure applied by the massage mechanism on the human body surface, and the force direction of the end of the massage mechanism is kept perpendicular to the human body surface, so that the massage end actuator always fits the human body surface, ensuring that the entire massage process of the human body is continuous and stable. Control rate 2 is applicable to the environmental speed The inequality constraints in the control are used to control the massage end actuator to adapt to the unknown characteristics on the human body surface, ensuring that the massage posture of the massage end actuator can be adjusted in real time according to the characteristics of the human back during the entire massage process to increase the comfort of the entire massage process. Control rate three is used to adjust the environmental acceleration Correction is made by adjusting the environmental acceleration intervention to coordinate the environmental position The equality constraints and ambient speed in The inequality constraints existing in the end position and end speed are used to deal with the instability of the control system caused by the sudden changes in the end position and end speed during the movement of the massage mechanism, thereby ensuring the safety of the entire massage process. The sudden changes in the end position and end speed are often caused by the human body suddenly turning over or changing the massage posture during the massage process.

[0121] The present invention obtains the required pressure applied by the massage mechanism on the human body surface by controlling the rate 1, and keeps the force direction of the end actuator of the massage mechanism perpendicular to the human body surface, ensuring that the massage end actuator always fits the human body surface, while ensuring that the entire massage process of the human body is continuous and stable.

[0122] By controlling the end position of the massage mechanism through control rate 2, it can adapt to the unknown features on the human body surface, ensuring that the massage posture of the massage end actuator can be adjusted in real time according to the characteristics of the human back during the entire massage process, so as to increase the comfort and adaptability of the entire massage process.

[0123] By controlling the rate three processing during the movement of the massage mechanism, the instability of the control system caused by the sudden change of the position and speed of the end actuator is eliminated, thus ensuring the safety of the entire massage process.

[0124] In addition, the present invention also combines the above three control rates with Cartesian impedance control to construct a simplified external environment impedance control model, which is used to generate the output torque of the joint; the motion trajectory generator proposed in the present invention can combine the actual operation trajectory and the planned operation trajectory of the massage mechanism to generate the environmental operation trajectory of the external environment impedance control model in real time, and use it as the input of the external environment impedance control model. Through continuous iterative calculation, the optimal massage trajectory for each massage action is planned.

[0125] During the entire massage process, control rates one, two and three ensure the continuous stability, comfort, adaptability and safety of the massage process; at the same time, combined with Cartesian impedance control, the best massage path can be planned in real time according to the external environment of the human back, and the best massage torque can be output at the same time, ultimately realizing a variety of massage techniques in traditional Chinese medicine massage.

[0126] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for constructing a massage control system, characterized in that: The steps include: A control rate u1 applicable to the equality constraint is defined to obtain the required pressure applied by the massage mechanism on the human body surface and to keep the end force direction of the massage mechanism perpendicular to the human body surface; A control rate u2 applicable to the inequality constraint is defined to control the end position of the massage mechanism so as to adapt it to the unknown features existing on the surface of the human body; A control rate u3 applicable to both equality constraints and inequality constraints is defined to handle the instability of the control system caused by sudden changes in the end position and end speed during the movement of the massage mechanism; Based on control rate 1 u1, control rate 2 u2 and control rate 3 u3, combined with Cartesian impedance control, a simplified external environment impedance control model is constructed, and the external environment impedance control model is used to generate the output torque of the joint; A motion trajectory generator is proposed. It combines the actual operation trajectory and planned operation trajectory of the massage mechanism to generate the environmental operation trajectory of the external environmental impedance control model in real time and uses it as the input of the external environmental impedance control model.

2. The method for constructing a massage control system according to claim 1, characterized in that: The expression of the control rate-u1 variable structure control is: Among them, φ eq is a function that contains all equality constraints φ eq,i Column vector, scalar Indicates that in the direction of the vector field f eq,i Lie derivative of (x), row vector Represents a set of vector fields g in the direction φ eq,i Lie derivative of (x), column vector L f φ eq Contains all equality constraints L f φ eq,i , the matrix L g φ eq The row vector L containing all the equality constraints g φ eq,i , sign(·) represents the sign function, positive scalar represents the switching gain, which can be constant or time-varying, W eq represents the diagonal matrix for switching gain weights under constraints, ‖·‖1 represents the 1-norm, and the function diag min (·) Computes the minimum value of the diagonal elements of a matrix.

3. The method for constructing a massage control system according to claim 2, characterized in that: The expression of the control rate u2 variable structure control is: Among them, the function v2dm(·) converts the vector into a diagonal matrix, the function pos(·) represents a positive function, that is, when x<0, pos(x) is equal to 0, when x>0, pos(x) is equal to 1, φ in is a column vector containing all inequality constraint functions φ in,i , the matrix L g φ in The row vector L containing all inequality constraints g φ in,i , scalar represents the direction of the vector field f in,i Lie derivative of (x), row vector. Represents a set of vector fields g in the direction φ in,i Lie derivative of (x), a positive scalar is the switching gain, W in is a diagonal matrix representing the switching gain weights under inequality constraints, n a is the number of inequality constraints, i.e., in,i The number of constraints that are ≤0.

4. The method for constructing a massage control system according to claim 3, characterized in that: The expression of the control rate u3 variable structure control is: in, + u + is the switching gain of the global sliding mode control, and its lower bound expression is:

5. The method for constructing a massage control system according to claim 4, characterized in that: The simplified external environmental impedance control model uses a mass-spring-damper system, which is expressed as: Where M e is the quality coefficient, D e is the damping coefficient, K e is the spring constant, F ext is the external force in Cartesian space, for environmental location; The specific expression is: Among them, x0 is the planned position and x is the actual position; The expression of the output torque τ in the joint space is: Where J is the Jacobian matrix of the manipulator, J T is the Jacobian matrix transpose of the manipulator, q is the generalized angle vector of the joint, M(q) is the inertia matrix, is the Coriolis force matrix, and G(q) is the gravity matrix.

6. The method for constructing a massage control system according to claim 5, characterized in that: The environmental running trajectory generated by the motion trajectory generator is specifically divided into an acceleration phase, a uniform speed phase and a deceleration phase; The acceleration phase constraint expression of the robot execution speed is: if but in, are the acceleration and deceleration parameters of the motion trajectory generator, is the actual speed, is the speed at the last sampling, x0 is the planned position, is the planned speed; The uniform speed phase constraint expression of the robot execution speed is: if but in, The maximum speed of the motion trajectory generator. The expression of the deceleration phase restriction condition of the robot execution speed is: if but in, is the distance from the current actual position x to the planned position x0.

7. A massage control method, a massage control system established based on any massage control system construction method of claims 1-6, characterized in that: The steps include: Combining the actual operation trajectory and the planned operation trajectory of the massage mechanism, the environmental operation trajectory of the external environmental impedance control model is generated in real time, and is used as the input of the simplified external environmental impedance control model; According to the environment running trajectory and the generalized motion trajectory of the joint, the output torque of the joint is generated, the joint motor action of the joint is controlled, and the corresponding massage action is performed; The generalized motion trajectory of the joints is detected in real time and converted into the actual operation trajectory of the massage mechanism.

8. A massage therapy robot, comprising a manipulator and a massage mechanism installed at the end of the manipulator, characterized in that: The massage control system established based on any massage control system construction method of claims 1-6 further comprises: a motion trajectory generator, which is used to generate an environmental operation trajectory of the external environmental impedance control model in real time by combining the actual operation trajectory and the planned operation trajectory of the massage mechanism, and use it as an input of the simplified external environmental impedance control model; A simplified external environment impedance control model, based on control rate one, control rate two and control rate three, combined with Cartesian impedance control, is used to generate the output torque of the joint according to the environmental operation trajectory and the generalized motion trajectory of the joint, control the joint motor action of the joint, and perform the corresponding massage action; Sensors for detecting the joint generalized motion trajectory of the joint in real time; The kinematic model, based on the generalized motion trajectory of the joints, is used to transform and generate the actual operation trajectory of the massage mechanism.

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