A physiotherapy massage robotic hand based on a six-dimensional force control system

Abstract

This invention discloses a physiotherapy massage robot based on a six-dimensional force control system. The device includes a base and a robotic arm body, which is mounted on the base. A robotic arm end flange is fixedly attached to the end of the robotic arm body, and a massage actuator is connected to the end flange. The massage actuator is connected to a massage end connecting flange, and a six-dimensional force sensor is installed on the massage end connecting flange. Both the six-dimensional force sensor and the robotic arm body are electrically connected to a human-machine interface. This invention uses a six-dimensional force sensor to perceive the force and torque in three translational and three rotational directions when the massage end contacts the human body in real time and accurately. Based on this feedback, closed-loop control is performed, fundamentally solving the problems of single-dimensional force control and insufficient precision in existing technologies. This results in uniform and smooth massage force, significantly improving massage comfort and therapeutic effects.

Description

Technical Field

[0001] This invention belongs to the field of physiotherapy equipment technology, and in particular relates to a physiotherapy massage robotic hand based on a six-dimensional force control system. Background Technology

[0002] Therapeutic massage equipment on the market can be mainly divided into two categories. The first category is traditional fixed massage chairs, which usually have built-in mechanical actuators based on simple cams, linkages, or airbags. They operate according to preset trajectories and intensity programs to achieve large-area kneading, tapping, or vibration functions. The second category is more basic mechanical massagers or massage arms. These devices may have multi-degree-of-freedom motion capabilities, but the control of their end effectors (massage heads) mostly relies on open-loop position control or simple single-axis pressure switch feedback. Some high-end products attempt to introduce sensors, such as integrating single-axis pressure sensors inside the massage head or installing encoders at the joints, for coarse adjustment of output force or recording of movement position. However, the core control logic of these technical solutions remains at the level of position servoing or one-dimensional force sensing, and their force control accuracy, spatial adaptability, and interactive safety are fundamentally limited.

[0003] Specifically, the existing technology mainly suffers from the following interrelated core defects: 1. Limited force control dimension and insufficient precision: The device cannot simultaneously sense and control the force and torque between the massage end and the human body in three directions, resulting in a stiff massage process that is prone to causing discomfort or potential damage. 2. Poor adaptability and lack of flexibility: Due to the lack of high-dimensional force feedback, the device is difficult to make adaptive and flexible adjustments according to the human body contour and tissue hardness (such as muscles and bones), resulting in fixed massage techniques and a lack of personalization; 3. Passive safety mechanisms and delayed response: Safety protection relies heavily on physical limits or overload protection, which cannot achieve proactive prevention and rapid intervention based on real-time analysis of multi-dimensional force interaction, thus posing safety hazards. 4. Low level of intelligence in human-computer interaction: The system cannot effectively integrate the user's real-time physiological feedback (such as facial expressions and voice), the interaction method is simple, and it is difficult to provide a personalized and responsive physiotherapy experience.

[0004] The root cause of these defects lies in the low perception dimension, simple control strategy, and isolated modules of the existing technology. To solve the above problems, a physiotherapy massage robot hand based on a six-dimensional force control system is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a physiotherapy massage robotic hand based on a six-dimensional force control system, thereby solving the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to a physiotherapy massage robot based on a six-dimensional force control system, comprising an overall device including a base and a robotic arm body mounted on the base. A robotic arm end flange is fixedly provided at the end of the robotic arm body, and a massage execution end is connected to the end flange. The massage execution end is connected to a massage end connecting flange, and a six-dimensional force sensor is mounted on the massage end connecting flange. Both the six-dimensional force sensor and the robotic arm body are electrically connected to a human-machine interface. The human-machine interface receives force and torque signals from the six-dimensional force sensor and controls the movement of the robotic arm body according to a preset massage strategy, thereby achieving precise closed-loop control of contact forces in three-dimensional space during the massage process and adaptively adjusting the massage movements in real time based on human body feedback.

[0007] Preferably, the main body of the robotic arm is a multi-degree-of-freedom serial robotic arm, including a first joint, a second joint, a third joint, a fourth joint, a fifth joint, and a sixth joint connected in sequence.

[0008] Preferably, each joint of the robotic arm body is equipped with a servo motor and a harmonic reducer. The servo motor and harmonic reducer are used to drive the joint movement of the robotic arm body, and the servo motor has a built-in encoder for real-time feedback of the joint position.

[0009] Preferably, the arm of the main body of the robotic arm is a lightweight hollow arm structure, which includes an outer carbon fiber woven shell and an inner lightweight honeycomb core material. The massage execution end includes a massage head, a drive mechanism, a pressure distribution sensor and a temperature control module. The temperature control module includes a heating element for heating and a temperature sensor for monitoring temperature.

[0010] Preferably, the human-machine interface includes a main controller, a joint controller, a force controller, a safety monitoring unit, and a communication module. The safety monitoring unit includes a force threshold monitoring module, which is used to monitor the force signal fed back by the six-dimensional force sensor in real time and trigger a safety response when the force value exceeds a preset safety threshold.

[0011] Preferably, the surface of the massage head is covered with a medical-grade silicone coating, which is replaceable. The drive mechanism includes a miniature DC motor and an eccentric wheel, used to drive the massage head to rotate, vibrate, or oscillate.

[0012] Preferably, the six-dimensional force sensor includes a strain gauge, a Wheatstone bridge, a signal conditioning circuit connected to the Wheatstone bridge, and a CAN bus interface connected to the signal conditioning circuit.

[0013] Preferably, the human-machine interface adopts a layered architecture, including a main controller, a joint controller, and a force controller. The human-machine interface adopts a position-force hybrid control strategy. The force controller calculates the force error compensation amount through a PID controller based on the feedback signal from the six-dimensional force sensor to adjust the position control command of the robotic arm. The human-machine interface also includes a power management module and a data storage module connected to the main controller.

[0014] Preferably, the human-machine interface further includes a safety monitoring unit for real-time monitoring of the system status and execution of a safety response when an anomaly is detected. The safety monitoring unit is connected to safety hardware, which includes an emergency stop button, a force limit switch, and an independent safety relay. When the safety monitoring unit or the safety hardware circuit triggers a safety condition, the independent safety relay can directly cut off the drive power supply to the robotic arm body.

[0015] Preferably, the human-computer interaction terminal is connected to a multimodal user feedback acquisition system, which is used to collect user status feedback and includes a non-contact camera for capturing user facial expressions and an audio acquisition array for recognizing voice commands.

[0016] The present invention has the following beneficial effects: 1. This invention uses a six-dimensional force sensor to perceive the force and torque in three translational and three rotational directions when the massage end comes into contact with the human body in real time and accurately, and performs closed-loop control based on this feedback. This fundamentally solves the problem of single force control dimension and insufficient precision in the existing technology, making the massage force uniform and smooth, and significantly improving the comfort and therapeutic effect of the massage. 2. This invention significantly improves the system's adaptability and movement compliance. Thanks to high-precision six-dimensional force feedback, the system can "sense" differences in human body contours and tissue stiffness in real time, and dynamically adjust the compliance parameters and movement trajectory of the robotic arm. This allows the robotic arm to adapt to different users' body shapes and the characteristics of different body parts (such as muscles and bones) of the same user, just like a professional physiotherapist, to achieve personalized and precise massage. 3. This invention constructs an active, real-time, multi-layered safety protection mechanism: by monitoring multi-dimensional force interaction information in real time and comparing it with preset safety thresholds, the system can trigger active intervention the moment abnormal force occurs (such as when a user suddenly moves or encounters a bony protrusion), realizing a graded safety response from early warning and deceleration to emergency braking. This changes the limitations of existing technologies that rely on passive and delayed protection, and greatly improves the inherent safety of equipment use. 4. This invention supports intelligent, multimodal human-computer interaction experience: The system can be integrated with external sensors such as cameras and microphones to form a multimodal user feedback acquisition system. This enables the device to not only respond to the user's active commands, but also to intelligently judge the user's comfort and state by analyzing physiological signals such as facial expressions and voice tone, thereby dynamically adjusting the massage strategy and providing truly personalized and responsive intelligent physiotherapy services.

[0017] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the installation position and connection relationship of the six-dimensional force sensor of the present invention; Figure 3 This is a block diagram of the hardware architecture of the human-computer interaction terminal of the present invention; Figure 4 This is a detailed structural diagram of the massage execution end of the present invention; Figure 5 This is a schematic diagram of the robotic arm joint connection structure of the present invention; Figure 6 This is a schematic diagram of the working principle of the safety protection system of the present invention; Figure 7 This is a flowchart of the force control algorithm of the present invention.

[0020] The components represented by each number in the attached diagram are listed below: 100. Overall equipment; 101. Base; 102. Main body of the robotic arm; 103. Six-dimensional force sensor; 104. Massage actuator; 105. Human-machine interface; 110. First joint; 111. Second joint; 112. Third joint; 113. Fourth joint; 114. Fifth joint; 115. Sixth joint; 120. Strain gauge; 121. Wheatstone bridge; 122. Signal conditioning circuit; 123. CAN bus interface; 130. Massage head; 131. Drive mechanism; 132. Pressure... 133. Distributed sensor; 134. Temperature control module; 135. Medical silicone covering layer; 136. Miniature DC motor; 137. Eccentric wheel; 138. Heating element; 149. Temperature sensor; 140. Main controller; 141. Joint controller; 142. Force controller; 143. Safety monitoring unit; 144. Communication module; 150. Emergency stop button; 153. Independent safety relay; 154. Force threshold monitoring module; 180. Robotic arm end flange; 181. Massage end connection flange; 182. Power management module; 183. Data storage module. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "upper," "middle," "outer," "inner," etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0023] Please see Figures 1-7As shown, this invention is a physiotherapy massage robot based on a six-dimensional force control system, comprising a device assembly 100. The device assembly 100 mainly includes a base 101, a robotic arm body 102, a six-dimensional force sensor 103, a massage execution end 104, and a human-machine interface 105. The robotic arm body 102 is fixedly mounted on the base 101. A robotic arm end flange 180 is fixedly mounted at the end of the robotic arm body 102, and the massage execution end 104 is connected to the robotic arm end flange 180. A six-dimensional force sensor 103 is installed between the massage execution end 104 and the robotic arm end flange 180 via the massage end flange 181. Both the six-dimensional force sensor 103 and the robotic arm body 102 are electrically connected to the human-machine interface 105. The human-machine interface 105 receives the force and torque signals fed back in real time from the six-dimensional force sensor 103 and controls the movement of the robotic arm body 102 according to a preset massage strategy, thereby achieving precise closed-loop control of the contact force in three-dimensional space during the massage process and adaptively adjusting the massage movements in real time based on human body feedback.

[0024] To achieve complex movements in three-dimensional space, the main body of the robotic arm 102 is a multi-degree-of-freedom serial robotic arm, such as... Figure 5 As shown, it specifically includes a first joint 110, a second joint 111, a third joint 112, a fourth joint 113, a fifth joint 114 and a sixth joint 115 connected in sequence, for a total of six rotary joints, providing the end effector with full flexibility in space.

[0025] Each joint is equipped with a servo motor and harmonic reducer (not shown in the figure), which together form a drive unit to drive the precise movement of the corresponding joint. The servo motor has an encoder (not shown in the figure) built in it to provide real-time feedback on the rotational position of each joint, providing accurate position feedback information to the human-machine interface 105, thus forming the basic closed loop of motion control.

[0026] To optimize performance, the arm of the main body 102 adopts a lightweight hollow arm structure, which specifically includes an outer carbon fiber woven shell and an inner lightweight honeycomb core material. This design significantly reduces the motion inertia of the robotic arm while ensuring structural rigidity and strength, thereby improving the dynamic response speed and control accuracy of the system.

[0027] The massage actuator 104 is a functional module that directly acts on the user's body. Specifically, it includes a massage head 130, a drive mechanism 131, a pressure distribution sensor 132, and a temperature control module 133. The massage head 130 is covered with a medical-grade silicone coating 134 and is designed for quick replacement to accommodate different massage techniques such as point pressure and kneading. The drive mechanism 131 includes a miniature DC motor 135 and an eccentric wheel 136. The motor drives the eccentric wheel to rotate, which in turn causes the massage head 130 to produce various complex movements such as rotation, vibration, or oscillation to simulate professional physiotherapy techniques.

[0028] The temperature control module 133 integrates a heating element 137 and a temperature sensor 138. The heating element 137 is used to heat the contact surface of the massage head to achieve the effect of hot compress therapy. The temperature sensor 138 monitors the temperature of the contact surface in real time to ensure that the temperature is within a safe and comfortable set range, and forms a temperature closed loop with the control logic.

[0029] The human-computer interaction terminal 105 is the core of intelligent control, and it adopts a layered architecture, such as... Figure 3 As shown, its main hardware includes: a main controller 140, a joint controller 141, a force controller 142, a safety monitoring unit 143, and a communication module 144. The main controller 140 serves as the system decision center, responsible for overall task scheduling, massage program parsing, motion path planning, and data interaction with external components (such as the data storage module 182). The joint controller 141 receives instructions from the upper-level controller and precisely drives the servo motors of each joint of the robotic arm body 102. The force controller 142 is the core algorithm unit for achieving precise force control. It adopts a position-force hybrid control strategy. Specifically, the system first generates the desired end position command (position loop) based on the massage path. At the same time, the force controller 142 receives feedback data from the six-dimensional force sensor 103 in real time and compares it with the target force value set according to the current technique. The force error compensation amount is calculated through the built-in PID controller (not shown in the figure). This compensation amount is used to dynamically adjust the position command sent to the joint controller 141, so that the robotic arm can accurately maintain or track the desired contact force during movement, achieving compliant and adaptive force interaction.

[0030] The safety monitoring unit 143 includes a force threshold monitoring module 154, which continuously monitors the force signals fed back by the six-dimensional force sensor 103. Once the force value in any direction exceeds the preset safety threshold, the module will immediately trigger a safety response, such as sending instructions to the force controller 142 and the joint controller 141 to reduce the force, slow down, or stop the movement. In addition, the human-machine interface terminal 105 also includes a power management module 182 and a data storage module 183 connected to the main controller 140, which provide a stable power supply and storage space for program and user data, respectively.

[0031] like Figure 2 As shown, the six-dimensional force sensor 103 is the key component for force sensing. Its core sensing element is a strain gauge 120, which is attached to the sensor's elastic body in a specific manner and connected to form a Wheatstone bridge 121. When the sensor is subjected to multidimensional forces / torques, the elastic body produces strain, causing the Wheatstone bridge 121 to lose balance and output a weak analog voltage signal.

[0032] This signal is then input to the signal conditioning circuit 122, where it is amplified, filtered, and converted from analog to digital. After processing, it is transformed into a high-precision, interference-resistant digital signal. Finally, the digital signal is transmitted at high speed and reliably to the force controller 142 of the human-machine interface 105 via the CAN bus interface 123, providing a real-time data source for closed-loop force control.

[0033] To ensure absolute safety, the safety monitoring unit 143 not only performs software monitoring, but is also connected to an independent hardware safety circuit, which includes an emergency stop button 150, a force limit switch 151, and an independent safety relay 153.

[0034] The safety monitoring unit 143 monitors the system status in real time. Once an anomaly is detected through force threshold monitoring or other algorithms (such as associated user feedback), it can immediately execute responses such as speed reduction and pause at the software level. The independent safety relay 153 is connected in series in the main circuit of the robotic arm drive power supply. When the user presses the emergency stop button 150, or the hardware force limit switch 151 is triggered, or the software monitoring unit issues the highest level alarm, the independent safety relay 153 will directly act to unconditionally cut off the power supply to all drive motors of the robotic arm body 102, achieving the highest level of hardware interlocking and ensuring the safety of the user in any fault situation.

[0035] At the interaction level, the human-computer interaction terminal 105 is connected to a multimodal user feedback acquisition system via a communication module 144. This system integrates a non-contact camera for capturing user facial expressions and an audio acquisition array for recognizing voice commands. By analyzing the user's real-time facial expressions and voice, the system can intelligently determine the user's comfort level and intentions, and feed this information back to the main controller 140 of the human-computer interaction terminal 105, thereby dynamically adjusting the massage strategy to achieve truly intelligent and personalized physiotherapy services.

[0036] Working principle: The system first receives user commands through the human-machine interface 106. The main controller 140 calls the massage strategy pre-stored in the data storage module 183 to generate the end effector trajectory of the robotic arm 102. As the robotic arm 102 approaches the human body, the six-dimensional force sensor 103 detects and feeds back the three-dimensional force and three-dimensional torque information of the contact point to the force controller 142 in real time. The force controller 142 adopts a position-force hybrid control strategy: on the one hand, it controls the position according to the preset path; on the other hand, it compares the measured force value of the six-dimensional force sensor 103 with the target force value, calculates the force error compensation amount through the PID controller, and combines the compliance parameters of the current body part, such as increasing compliance in the muscle area and increasing rigidity near the bone, to dynamically adjust and send the position command to the joint controller 141, so that the robotic arm 102 moves in a certain direction. Throughout the exercise, precise and gentle force is applied. Simultaneously, the massage execution end 104 drives the massage head 130 to perform rotation, vibration, and other actions according to the program, while the temperature control module 133 achieves constant temperature heat therapy. The safety monitoring unit 143 continuously analyzes the data from the six-dimensional force sensor 103 and multimodal user feedback such as facial expressions and voice. When it detects excessive force or user discomfort, it immediately triggers a multi-level safety response, from software deceleration to hardware emergency stop. Among them, the independent safety relay 153 can directly cut off the drive power of the robotic arm body 102 to achieve the highest level of protection. The entire process forms a real-time adaptive cycle of "sensing contact force - comparing target value - calculating compensation amount - adjusting movement - continuous monitoring - intelligent feedback," thereby simulating the precise, safe, and personalized massage effect of a professional therapist who "reads the room and follows the force." In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A physiotherapy massage robotic hand based on a six-dimensional force control system, comprising an overall device (100), characterized in that, The device as a whole (100) includes a base (101) and a robotic arm body (102), the robotic arm body (102) being mounted on the base (101); The end of the robotic arm body (102) is fixedly provided with a robotic arm end flange (180), the robotic arm end flange (180) is connected to a massage execution end (104), the massage execution end (104) is connected to a massage end connecting flange (181), a six-dimensional force sensor (103) is installed on the massage end connecting flange (181), and the six-dimensional force sensor (103) and the robotic arm body (102) are both electrically connected to a human-machine interface (105). The human-machine interface (105) is used to receive force and torque signals fed back by the six-dimensional force sensor (103) and control the movement of the robotic arm body (102) according to the preset massage strategy, so as to realize the precise closed-loop control of the contact force in the three-dimensional space during the massage process, and to adjust the massage action in real time according to human feedback.

2. The physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The main body of the robotic arm (102) is a multi-degree-of-freedom serial robotic arm, including a first joint (110), a second joint (111), a third joint (112), a fourth joint (113), a fifth joint (114) and a sixth joint (115) connected in sequence.

3. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 2, characterized in that, Each joint of the robotic arm body (102) is equipped with a servo motor and a harmonic reducer. The servo motor and harmonic reducer are used to drive the joint movement of the robotic arm body (102), and the servo motor has an encoder built in for real-time feedback of the joint position.

4. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 3, characterized in that, The arm of the main body (102) of the robotic arm is a lightweight hollow arm structure, which includes an outer carbon fiber woven shell and an inner lightweight honeycomb core. The massage execution end (104) includes a massage head (130), a drive mechanism (131), a pressure distribution sensor (132) and a temperature control module (133). The temperature control module (133) includes a heating element (137) for heating and a temperature sensor (138) for monitoring temperature.

5. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The human-machine interface (105) includes a main controller (140), a joint controller (141), a force controller (142), a safety monitoring unit (143), and a communication module (144). The safety monitoring unit (143) includes a force threshold monitoring module (154), which is used to monitor the force signal fed back by the six-dimensional force sensor (103) in real time and trigger a safety response when the force value exceeds the preset safety threshold.

6. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 4, characterized in that, The massage head (130) is covered with a medical silicone coating (134) and is a replaceable structure. The drive mechanism (131) includes a micro DC motor (135) and an eccentric wheel (136) for driving the massage head (130) to rotate, vibrate or swing.

7. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The six-dimensional force sensor (103) includes a strain gauge (120), a Wheatstone bridge (121), a signal conditioning circuit (122) connected to the Wheatstone bridge (121), and a CAN bus interface (123) connected to the signal conditioning circuit (122).

8. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The human-machine interface (105) adopts a hierarchical architecture, including a main controller (140), a joint controller (141) and a force controller (142). The human-machine interface (105) adopts a position-force hybrid control strategy. The force controller (142) calculates the force error compensation amount through a PID controller based on the feedback signal of the six-dimensional force sensor (103) to adjust the position control command of the robotic arm. The human-machine interface (105) also includes a power management module (182) and a data storage module (183) connected to the main controller (140).

9. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The human-machine interface (105) also includes a safety monitoring unit (143) for real-time monitoring of system status and execution of safety response when an anomaly is detected. The safety monitoring unit (143) is connected to safety hardware. The safety hardware circuit includes an emergency stop button (150), a force limit switch (151), and an independent safety relay (153). When the safety monitoring unit (143) or the safety hardware circuit triggers a safety condition, the independent safety relay (153) can directly cut off the drive power of the robotic arm body (102).

10. A physiotherapy massage robotic hand based on a six-dimensional force control system according to claim 1, characterized in that, The human-computer interaction terminal (105) is connected to a multimodal user feedback acquisition system, which is used to collect user status feedback. The multimodal user feedback acquisition system includes a non-contact camera for capturing user facial expressions and an audio acquisition array for recognizing voice commands.

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