Upper limb rehabilitation robot based on planar parallel mechanism and control system thereof

Abstract

The invention provides an upper limb rehabilitation robot based on a planar parallel mechanism and a control system thereof, the mechanical structure of the robot comprises a planar five-connecting-rod mechanism comprising a fixed base (1), and the power input end of the planar five-connecting-rod mechanism is connected with a motor array at the fixed base; a hand fixing and supporting part is arranged at the power output end of the planar five-connecting-rod mechanism; a hand supporting plate (7) for a user to place the hand and a handle (6) for the user to hold are arranged on the hand fixing and supporting component, and the motor array outputs preset resistance through the planar five-connecting-rod mechanism and drives the hand fixing and supporting component to move according to a preset track so as to provide upper limb rehabilitation training for the user. The plane five-connecting-rod mechanism limits the movement of the connecting rod through a built-in limiting protection mechanism, so that dead points of the plane five-connecting-rod mechanism during upper limb rehabilitation training are avoided. Accurate adjustment of training impedance and real-time feedback of motion data can be achieved, and rehabilitation training efficiency and patient compliance are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rehabilitation medical equipment, in particular to an upper limb rehabilitation robot based on a planar parallel mechanism and a control system thereof, and specifically relates to an end effector type upper limb rehabilitation training robot for middle and late stage impedance training of stroke patients. BACKGROUND

[0002] With the aggravation of population aging, the incidence of stroke is increasing year by year, and most patients will have upper limb motor dysfunction after the onset, which requires long-term rehabilitation training. Traditional rehabilitation training relies on manual operation of rehabilitation therapists, and there are problems such as insufficient number of therapists, limited training intensity and frequency, and high labor cost.

[0003] Existing upper limb rehabilitation robots are mainly divided into two types: exoskeleton type and end effector type. The exoskeleton type has good support, but the structure is complex, the weight is large, and the cost is high. The end effector type has a relatively simple structure, but it generally has problems such as insufficient freedom of movement, low training impedance adjustment precision, poor human-computer interaction, and most devices cannot realize real-time visual feedback of training data, which makes it difficult to meet the individual rehabilitation needs of patients and is not conducive to therapists to evaluate the training effect. In addition, some robots have poor wearing comfort or the movement range cannot adapt to patients of different heights and arm lengths, which restricts the clinical popularization and application.

[0004] To solve the above problems, the present application proposes an end effector type upper limb rehabilitation training robot, which optimizes the mechanical structure design, improves the control strategy and enhances the human-computer interaction function, realizes precise adjustment of training impedance and real-time feedback of movement data, and at the same time considers the structure simplification, cost control and adaptability, so as to improve the rehabilitation training efficiency and patient compliance. SUMMARY

[0005] The present application proposes an end effector type upper limb rehabilitation training robot for middle and late stage impedance training of stroke patients, which optimizes the mechanical structure design, improves the control strategy and enhances the human-computer interaction function, realizes precise adjustment of training impedance and real-time feedback of movement data, and at the same time considers the structure simplification, cost control and adaptability, so as to improve the rehabilitation training efficiency and patient compliance, and can solve the problems of complex structure, low impedance adjustment precision, poor human-computer interaction and insufficient adaptability of existing upper limb rehabilitation robots.

[0006] The present application adopts the following technical solutions.

[0007] The upper limb rehabilitation robot based on a planar parallel mechanism comprises a planar five-link mechanism including a fixed base (1), a motor array connected to a power input end of the planar five-link mechanism and the fixed base, and a hand fixing and supporting part provided at a power output end of the planar five-link mechanism; the hand fixing and supporting part is provided with a hand supporting plate (7) for placing a hand of a user and a handle (6) for holding by the user; the motor array outputs a preset impedance force through the planar five-link mechanism and drives the hand fixing and supporting part to move along a preset trajectory to provide upper limb rehabilitation training for the user; and the planar five-link mechanism is provided with a built-in limiting protection mechanism (4) for limiting the movement of the links to avoid the occurrence of a dead point of the planar five-link mechanism during the upper limb rehabilitation training.

[0008] As shown in Figure 1 the motor array comprises two motors (2); the planar five-link mechanism comprises a C end for fixing the supporting plate and the handle, an A end and an E end for fixing the two motors, the A end and the E end are located at two ends of a stationary rod L5 at the fixed base, the motor at the A end is a first motor connected to a link L1 of the planar five-link mechanism, the motor at the E end is a second motor connected to a link L4 of the planar five-link mechanism, a D end of the link L4 is hinged to a link L3 of the five-link mechanism, and a B end of the link L1 is hinged to a link L2 of the five-link mechanism. Figure 1 In the planar five-link mechanism, the link L1 is a rod AB (3), the link L2 is a rod BC (5), the link L3 is a rod CD (8), and the link L4 is a rod DE (9).

[0009] The limiting protection mechanism comprises a plurality of blocking pins arranged at the hinge joints of the links; the blocking pins are matched with the arc-shaped structures at the links and form physical limiting structures for limiting the rotation angles of the links, so as to ensure that the hand fixing and supporting part of the end effector moves within a preset movement range and avoid the formation of a concave five-sided structure of the planar five-link mechanism during movement.

[0010] The fixed base is provided with a conical pin hole for fixing the motor, a screw stepped hole, and a groove for the wiring of the power signal lines of the motor; The fixed base is provided with four through holes for connecting and fixing the fixed base with a desktop or a supporting platform through fasteners.

[0011] The links L1, L2, L3, L4 and L5 are all made of thick acrylic plates cut by laser, the hinge joints of the links are all provided with flange deep groove ball bearings, and the inner rings and washers of the bearings are fixed to the links through sub-mother screws to ensure flexible rotation without jamming.

[0012] The hand supporting plate is provided with universal wheels (10) for supporting the plate; the surface of the hand supporting plate adopts a curved structure that can fit the human arm, and two square holes are provided for fixing the hand with magic tape; the universal wheels are installed below the hand supporting plate for supporting the weight of the arm to avoid deformation caused by the cantilever beam structure of the hand supporting plate; the handle is rigidly connected with the hand supporting plate and fixed with the hinge points of the connecting rods L2 and L3, and serves as the force receiving and motion output end of the end effector; The upper limb rehabilitation robot control system based on the planar parallel mechanism uses the upper limb rehabilitation robot based on the planar parallel mechanism, and when the "middle and late stage impedance training" demand of the stroke patient is processed, the control system adjusts the impedance parameters by controlling the motor output force to simulate the real motion scene (such as active motion with load such as lifting and pushing) in the rehabilitation exercise to help the user recover the muscle strength and motion coordination, and the control object is impedance (including damping parameters) rather than single damping; The parameters required for impedance adjustment are calculated through the dynamics of the five-bar mechanism, and the quantitative relationship between the motor output torque and the impedance of the end effector is established to ensure the accuracy of the impedance adjustment. First, the real-time position coordinates (x, y) of the end effector at the C end are calculated by solving the forward kinematics: the joint angles Φ1 and Φ4 corresponding to the motor output angle measured by the motor encoder are combined with the five-bar link lengths L1, L2, L3, L4 and L5; and then the Jacobian matrix J is mapped: based on the virtual work principle, the impedance F x , Fᵧ of the end effector is converted into the driving torques T1 and T2 of the two motors, and the formula is: The impedance (F x , Fᵧ) is: .

[0013] The control system adjusts the motor driving torque by adjusting the core control parameters of the motor, and the specific parameters include the feedforward torque τ ff Desired angular position p des Desired angular velocity ω des， Position stiffness k p， Velocity stiffness (damping) k d , In the hybrid control of the motor, the final output torque of the motor is calculated by the PD (proportional-differential) controller, and the formula is: The control system is based on the dynamics model of the planar five-bar linkage, and the training impedance required by the patient is converted into the driving torque executable by the motor through forward kinematics calculation and Jacobian matrix mapping. The driving torque applied by the motor is changed to match the middle and late stage impedance training needs of patients with different muscle strength levels.

[0014] The control system is based on the dynamics model of the planar five-bar linkage, and the training impedance required by the patient is converted into the driving torque executable by the motor through forward kinematics calculation and Jacobian matrix mapping. The driving torque applied by the motor is changed to match the middle and late stage impedance training needs of patients with different muscle strength levels. L 1 、 L 2 、 L 3 、 L 4 、 L 5 The lengths of the five connecting rods in the kinematics model of the five-bar linkage are known constants, and the two rotary pairs at the A and E ends are driven by the motor, and the angles Φ 1 、 Φ 4 are measured by the built-in encoder of the motor, Let Φ 2 be the acute angle between the connecting rod L 2 and the horizontal line, Φ 3 be the obtuse angle between the connecting rod L 3 and the horizontal line, The coordinates of the C point at the end of the five-bar linkage are obtained through kinematics calculation, and are represented using rectangular coordinates (x, y). Assuming that the A point is located at the coordinate origin (0, 0), the E point coordinates are L 5 , 0); The coordinates of the B point are driven by Φ 1 , and the position equation is The coordinates of the D point are driven by Φ 4 , and the position equation is According to the closed condition of the five-bar linkage, the coordinates of the C point are projected to the x-axis and y-axis through the left and right parts of the five-bar linkage, and the position equation of the C point is obtained where is obtained: where​ is the distance from point B to point D; is simplified to a linear combination form The system in which respectively The auxiliary angle is defined , and the solution is According to the results of Φ 2 The rectangular coordinates of point C are calculated Φ 3 The value of is calculated by the following formula using the coordinates of point C .

[0015] The control system includes the following functions; Training parameter setting: support motion graphics (circle, rectangle, ellipse, 8-shaped, no fixed track), graphic size, training impedance setting; Data visualization: can display the predetermined trajectory and actual motion trajectory of the end effector, hand push force change curve, motor working state (temperature, output torque, angular velocity, position) in real time; Safety control: set the software form of emergency stop button on the interactive interface, cooperate with the physical limit of the mechanical structure, when the end effector exceeds the preset motion range or the motor temperature exceeds 40℃, automatically stop training and issue an alarm prompt; Data storage: record the time, trajectory deviation, average push force and motor state data of each training, support export Excel format file, and facilitate the therapist to evaluate the rehabilitation progress; The steps of the use process specifically include; Parameter setting: set the trajectory to be executed by the end effector, select a certain motion graphics, input size, and set the training impedance; Training start: click "open serial port" on the human-computer interaction interface, click "start training", the motor outputs impedance according to the preset trajectory, the trajectory display area draws the predetermined trajectory and the actual trajectory in real time, and the push force change diagram displays the real-time push force and the set impedance; Data storage: after training, an Excel file containing training time, trajectory deviation, and average push force can be generated.

[0016] This invention is based on the dynamic model of a planar five-bar linkage. Through forward kinematics calculation and Jacobian matrix mapping, the training impedance required by the patient is converted into a driving torque that the motor can execute. By changing the driving torque applied by the motor, the mid-to-late stage impedance training needs of patients with different muscle strength levels can be met.

[0017] The beneficial effects of the end effector-type upper limb rehabilitation robot and its control method of the present invention are: 1. This invention adopts an end effector-type planar five-bar linkage structure, which reduces the number of parts and lowers the processing cost compared to exoskeleton robots, making it more suitable for clinical application.

[0018] 2. This invention has strong adaptability to movement. By optimizing the length of the five-link system, it can achieve a variety of movement ranges to meet the upper limb movement needs of adult patients of different heights. The arc design of the hand support plate, combined with the Velcro strap, improves wearing comfort. At the same time, the universal wheel support structure avoids the deformation of the link caused by the weight of the arm.

[0019] 3. The present invention provides precise impedance adjustment. Based on the integrated drive and control motor and the force-position hybrid control mode, it has a wide range of training impedance adjustment and high adjustment accuracy, meeting the mid-to-late stage impedance training needs of patients with different muscle strength levels. Through the dual safety design of limit protection mechanism and software emergency stop, the training process is ensured to be safe and reliable.

[0020] 4. This invention has excellent human-computer interaction, and displays motion trajectory, thrust changes and motor status data in real time. Patients can intuitively understand the training progress and deviations, and therapists can evaluate the rehabilitation effect through the exported training data. It supports a variety of motion graphics and custom size settings to realize the formulation of personalized rehabilitation training programs.

[0021] 5. This invention can apply end impedance to achieve three modes of patient rehabilitation training: active rehabilitation training, passive rehabilitation training, and impedance rehabilitation training. Attached Figure Description

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Appendix Φ This is a schematic diagram of the mechanical structure of an example of the present invention; Appendix Figure 1 This is a schematic diagram of the kinematic model of an example of the present invention; Appendix Figure 2 This is a schematic diagram of the limiting protection structure of an example of the present invention; Appendix Figure 3 This is a schematic diagram of the hand support structure in an example of the present invention; Appendix Figure 4 This is a cross-sectional view of the hand support structure in an example of the present invention; Appendix Figure 5Control system interface schematic diagram for the example of the present application.

[0023] Attachment Figure 6 Control system flowchart schematic diagram for the example of the present application.

[0024] In the figure: 1 - fixed base, 2 - motor (using Yushu motor), 3 - rod AB, 4 - limit protection mechanism, 5 - rod BC, 6 - handle, 7 - hand supporting plate, 8 - rod CD, 9 - rod DE, 10 - universal wheel. DETAILED DESCRIPTION

[0025] As shown in the figure, the upper limb rehabilitation robot based on planar parallel mechanism, the mechanical structure of the robot includes a planar five-bar mechanism containing a fixed base (1), the power input end of the planar five-bar mechanism is connected with the motor array at the fixed base, the power output end of the planar five-bar mechanism is provided with a hand fixing and supporting part; the hand fixing and supporting part is provided with a hand supporting plate (7) for placing the hand of the user and a handle (6) for holding by the user, the motor array outputs a preset impedance force through the planar five-bar mechanism and drives the hand fixing and supporting part to move according to a preset trajectory to provide upper limb rehabilitation training for the user, the planar five-bar mechanism limits the movement of its connecting rods by the built-in limit protection mechanism (4) to avoid the occurrence of dead points of the planar five-bar mechanism during upper limb rehabilitation training.

[0026] As Figure 7 shown, the motor array includes two motors (2); the planar five-bar mechanism includes a C end for fixing the supporting plate and the handle, an A end and an E end for fixing the two motors, the A end and the E end are located at the two ends of the stationary rod L5 at the fixed base, the motor at the A end is a first motor connected with the connecting rod L1 of the planar five-bar mechanism; the motor at the E end is a second motor connected with the connecting rod L4 of the planar five-bar mechanism, the D end of the connecting rod L4 is hinged with the connecting rod L3 of the five-bar mechanism, the B end of the connecting rod L1 is hinged with the connecting rod L2 of the five-bar mechanism; Figure 1 In the figure, the connecting rod L1 is the rod AB (3), the connecting rod L2 is the rod BC (5), the connecting rod L3 is the rod CD (8), and the connecting rod L4 is the rod DE (9).

[0027] The limit protection mechanism includes a plurality of blocking pins arranged at the hinge positions of the connecting rods; the blocking pins are matched with the arc-shaped structures at the connecting rods and form physical limiting structures for limiting the rotation angle of the connecting rods, so as to ensure that the hand fixing and supporting part of the end effector moves within a preset movement range and avoid the formation of a concave five-sided structure when the planar five-bar mechanism moves.

[0028] The fixed base is provided with a conical pin hole for fixing the motor, a screw stepped hole, and a groove for the wiring of the power signal lines of the motor; Four through holes are arranged on the fixing base, and the fixing base is connected and fixed with the tabletop or the supporting platform by fasteners.

[0029] The connecting rods L1, L2, L3, L4 and L5 are all made of thick acrylic plates cut by laser, flange deep groove ball bearings are arranged at the hinged portions of the connecting rods, and the inner rings and the connecting rods are fixed by the sub-mother screws and the washers, so that the rotation is flexible and free from jamming.

[0030] The hand supporting plate is provided with universal wheels (10) for supporting the plate; the surface of the hand supporting plate adopts a curved structure that can fit the human arm, and two square holes are arranged for fixing the hand by magic tape; the universal wheels are installed below the hand supporting plate for supporting the weight of the arm and avoiding deformation caused by the cantilever beam structure of the hand supporting plate; the handle is rigidly connected with the hand supporting plate and the hinged points of the connecting rods L2 and L3, and serves as a force receiving and motion output end of the end effector; The upper limb rehabilitation robot control system based on the planar parallel mechanism uses the upper limb rehabilitation robot based on the planar parallel mechanism, and when the control system processes the "middle and late stage impedance training" demand of a stroke patient, the impedance parameters are adjusted by controlling the motor output force to simulate a real motion scene (such as lifting, pushing and pulling active motion with load) in the rehabilitation motion, so as to help the user recover muscle strength and motion coordination, and the control object is impedance (including damping parameters) rather than single damping; The parameters required for impedance adjustment are calculated by the dynamics of the five-link mechanism, the quantitative relationship between the motor output torque and the impedance of the end effector is established to ensure the accuracy of the impedance adjustment, first, the real-time position coordinates (x, y) of the end effector at the C end are calculated by solving the forward kinematics: the joint angles Φ1 and Φ4 corresponding to the motor output rotation angle measured by the motor encoder are combined with the lengths L1, L2, L3, L4 and L5 of the five-link mechanism, and then the impedance F x , Fᵧ of the end effector is converted into the driving torques T1 and T2 of the two motors by the Jacobian matrix J mapping based on the virtual work principle, and the formula is: The impedance (F x , Fᵧ) is: .

[0031] The control system adjusts the motor driving torque by adjusting the core control parameters of the motor, and the specific parameters include the feedforward torque Figure 1 ff Desired angle position p des Desired angular velocity τ des， Position stiffnessk p， Velocity stiffness (damping) k d , In the hybrid control of the motor, the final output torque of the motor is calculated by a PD (proportional-differential) controller, and the formula is: The control system is based on the dynamics model of the planar five-bar linkage mechanism, and the required training impedance of the patient is converted into the driving torque executable by the motor through forward kinematics calculation and Jacobian matrix mapping. The driving torque applied by the motor is changed to match the mid-late stage impedance training needs of patients with different muscle strength levels.

[0032] The control system is based on the integrated motor control and the force-position hybrid control mode to accurately adjust the impedance. The force-position hybrid control mode is calculated through the kinematics model of the five-bar linkage mechanism. In the kinematics model of the five-bar linkage mechanism, the lengths of the five connecting rods L 1 , L 2 , L 3 , L 4 , L 5 are known constant values, and the two rotary pairs at A and E are driven by the motor, and the angles ω 1 , Φ 4 are measured by the built-in encoder of the motor. Let Φ 2 be the acute angle between the connecting rod L 2 and the horizontal line, Φ 3 be the obtuse angle between the connecting rod L 3 and the horizontal line, The coordinates of the end point C of the five-bar linkage mechanism are obtained through kinematics calculation, which are represented by rectangular coordinates (x, y). Let the A point be located at the coordinate origin (0, 0), then the E point coordinates are (x, 0). L 5 The coordinates of the B point are driven by Φ 1 , and the position equation is The coordinates of the D point are driven by Φ 4 , and the position equation is ​ According to the five-bar linkage closure condition, by the left and right two parts of the five-bar linkage, the C point coordinate is projected to the x axis and y axis, and the position equation of the C point can be obtained In the formula Wherein is the distance from B point to D point; Simplify to linear combination form The system is Define auxiliary angle , the solution is According to the result of Φ 2 The rectangular coordinates of C point are calculated Φ 3 The value of .

[0033] The control system includes the following functions; Training parameter setting: support motion graphics (circle, rectangle, ellipse, 8-shaped, no fixed track), graphic size, training impedance setting; Data visualization: can real-time display the predetermined trajectory and actual motion trajectory of the end effector, hand pushing force change curve, motor working state (temperature, output torque, angular velocity, position); Safety control: set the software form of emergency stop button at the interactive interface, cooperate with the physical limit of mechanical structure, when the end effector exceeds the preset motion range or the motor temperature exceeds 40℃, automatically stop training and issue alarm prompt; Data storage: record the time, trajectory deviation, average pushing force and motor state data of each training, support export Excel format file, convenient for therapist to evaluate rehabilitation progress; The steps of the use process specifically include; Parameter setting: set the trajectory to be executed by the end effector, select a certain motion graphics, input size, and set training impedance; Training start: click “open serial port” in the human-computer interaction interface, click “start training”, the motor outputs impedance according to the preset trajectory, the trajectory display area real-time draws the predetermined trajectory and actual trajectory, and the pushing force change diagram displays real-time pushing force and set impedance;​ Data storage: After the training is completed, an Excel file containing the training time, trajectory deviation, and average thrust can be generated.

[0034] Embodiment: A mechanical structure system of an end effector type upper limb rehabilitation training robot: comprising a fixed base, a planar five-link mechanism, a hand fixing and supporting part, and a limit protection mechanism; The fixed base is provided with a conical pin hole for fixing a motor, a screw stepped hole, and a groove for motor power signal line wiring, and four through holes are also provided, and the fixed base is connected and fixed with the desktop or support platform through fasteners; The planar five-link mechanism includes four acrylic links (L1, L2, L3, L4) and a stationary rod (L5) integrated with the fixed base, which is processed by laser cutting, wherein one end of L1 is connected with the first motor output end on the fixed base, and the other end is connected with L2; the other end of L2 is connected with L3, and the other end of L3 is connected with L4; the other end of L4 is connected with the second motor output end on the fixed base; double bearing fixing structure is adopted at each hinge, flanged deep groove ball bearings are used to fix the upper and lower ends, and washers are used to separate adjacent links in the middle, and the whole is fixed by sub-mother screw; ensure that the movement range of the end effector always maintains a convex pentagonal structure, avoiding dead point position; The hand fixing and supporting part includes a handle, a hand supporting plate, and a universal wheel; the hand supporting plate is designed to fit the human arm curve, and a square hole is provided for fixing the hand with magic tape; the universal wheel is installed below the hand supporting plate to support the weight of the arm and prevent the hand supporting plate from forming a cantilever beam structure; the handle is rigidly connected with the hand supporting plate and the hinge points of L2 and L3, and serves as the force receiving and movement output end of the end effector; The limit protection mechanism uses an inner hexagonal cylindrical head bolt as a stop pin, which is arranged at the hinge of adjacent links and cooperates with the arc structure on one of the links to form a physical limit, limiting the rotation angle of the link, ensuring that the end effector works within the preset movement range, and avoiding the formation of a concave pentagonal structure; In this example, the fixed base 1 is provided with two conical pin holes for positioning the motor 2, four screw stepped holes for fixing the motor 2, and a groove for motor power signal line wiring, and four through holes are provided at the corners of the base for fixing with the desktop through bolts; The planar five-link mechanism is assembled, and the links 3, 5, 8, and 9 are made of thick acrylic plates by laser cutting, flanged deep groove ball bearings are installed at each hinge, and the inner ring of the bearing, the washer, and the link are fixed by sub-mother screw, ensuring flexible rotation without jamming; The handle 6 is rigidly connected through bolts; the surface of the hand supporting plate 7 is arc-shaped to fit the curve of the forearm, two square holes are opened, and magic tape is passed through; the universal wheel 10 is installed at the center position below the hand supporting plate 7 through screws; The limiting protection mechanism 4 is a hexagonal head bolt installed between the connecting rods 3 and 5 and the connecting rods 8 and 9 as a stop pin, and the connecting rods 5 and 8 are processed with arc-shaped structures at the corresponding positions, so that the rotation angle of the connecting rods is limited within a certain range, and the dead point of the five connecting rod mechanism is avoided.

[0035] Based on the above rope-driven upper limb rehabilitation robot control method, as Φ Figure 2 shown.

[0036] Parameter setting: select a certain motion pattern, input size, and set training impedance; Training start: click "open serial port" and "start training", the motor outputs impedance according to the preset trajectory, the trajectory display area draws the preset trajectory and the actual trajectory in real time, and the thrust change diagram displays the real-time thrust and the set impedance; Data storage: after training, an Excel file containing training time, trajectory deviation and average thrust can be generated.

[0037] The end effector type upper limb rehabilitation training robot of the embodiment realizes precise impedance adjustment, individualized training and safe and reliable operation by simplifying the mechanical structure, optimizing the control strategy and enhancing the human-computer interaction function, and can effectively improve the upper limb rehabilitation training effect of stroke patients in the middle and late stages.

Claims

1. An upper limb rehabilitation robot based on planar parallel mechanism, characterized in that: The mechanical structure of the robot comprises a planar five-bar linkage mechanism comprising a fixed base (1), a motor array connected to the power input end of the planar five-bar linkage mechanism at the fixed base, and a hand fixing and supporting part provided at the power output end of the planar five-bar linkage mechanism; the hand fixing and supporting part is provided with a hand supporting plate (7) for placing the hand of a user and a handle (6) for holding by the user; the motor array outputs a preset impedance force through the planar five-bar linkage mechanism and drives the hand fixing and supporting part to move along a preset trajectory to provide upper limb rehabilitation training for the user; the planar five-bar linkage mechanism limits the movement of the connecting rods thereof by a built-in limiting protection mechanism to avoid dead points of the planar five-bar linkage mechanism during the upper limb rehabilitation training.

2. The upper limb rehabilitation robot based on planar parallel mechanism according to claim 1, characterized in that: The motor array comprises two motors (2); the planar five-bar linkage mechanism comprises a C end for fixing the supporting plate and the handle, an A end and an E end for fixing the two motors, the A end and the E end being located at the two ends of a stationary rod L5 at the fixed base, the motor at the A end being a first motor connected to a connecting rod L1 of the planar five-bar linkage mechanism, and the motor at the E end being a second motor connected to a connecting rod L4 of the planar five-bar linkage mechanism, a D end of the connecting rod L4 being hinged to a connecting rod L3 of the five-bar linkage mechanism, and a B end of the connecting rod L1 being hinged to a connecting rod L2 of the five-bar linkage mechanism.

3. The upper limb rehabilitation robot based on planar parallel mechanism according to claim 2, characterized in that: The limiting protection mechanism comprises a plurality of blocking pins arranged at the hinge joints of the connecting rods; the blocking pins are matched with the arc-shaped structures at the connecting rods and form physical limiting structures for limiting the rotation angles of the connecting rods, so as to ensure that the hand fixing and supporting part of the end effector moves within a preset movement range and avoid the formation of a concave five-sided structure of the planar five-bar linkage mechanism during movement.

4. The upper limb rehabilitation robot based on planar parallel mechanism according to claim 2, characterized in that: The fixed base is provided with a conical pin hole, a screw stepped hole for fixing the motor, and a groove for the wiring of the power supply signal lines of the motor; The fixed base is provided with four through holes for connecting and fixing the fixed base to the tabletop or supporting platform by fasteners.

5. The planar parallel mechanism based upper limb rehabilitation robot according to claim 2, wherein: The connecting rods L1, L2, L3, L4 and L5 are all made of thick acrylic plates cut by laser, and flange deep groove ball bearings are installed at the hinge joints of the connecting rods, and the inner rings and washers of the bearings are fixed to the connecting rods by sub-mother screws.

6. The planar parallel mechanism based upper limb rehabilitation robot according to claim 2, wherein: A universal wheel (10) for supporting the supporting plate is arranged below the hand supporting plate; the surface of the hand supporting plate adopts a curved structure that can fit the human arm, and a hole is provided for fixing the hand by a magic tape; the universal wheel is installed below the hand supporting plate to support the weight of the arm and avoid deformation of the hand supporting plate due to the formation of a cantilever beam structure; the handle is rigidly connected to the hand supporting plate and fixed to the hinge joints of the connecting rods L2 and L3, serving as the force receiving and movement output end of the end effector.

7. A control system of the upper limb rehabilitation robot based on planar parallel mechanism, using the upper limb rehabilitation robot based on planar parallel mechanism as claimed in claim 3, characterized in that: The control system adjusts the impedance parameters by controlling the output force of the motor to simulate real movement scenarios in the rehabilitation movement to help the user recover muscle strength and movement coordination when processing the "middle and late stage impedance training" requirements of stroke patients. The parameters required for impedance adjustment are calculated through the dynamics of the five-bar linkage mechanism, and the accuracy of impedance adjustment is ensured by establishing a quantitative relationship between the motor output torque and the impedance of the end effector. First, the real-time position coordinates (x, y) of the end effector at the C end are calculated by solving the forward kinematics: the joint angles Φ1, Φ4 corresponding to the motor output angle measured by the motor encoder are combined with the lengths L1, L2, L3, L4, L5 of the five-bar linkage, and the real-time position coordinates (x, y) of the end effector at the C end are calculated. Then, the Jacobian matrix J is mapped: based on the virtual work principle, the Jacobian matrix is derived, and the impedance F x , Fᵧ of the end effector is converted into the driving torques T1, T2 of the two motors, and the formula is: The impedance (F x , Fᵧ) is: 。 8. The planar parallel mechanism based upper limb rehabilitation robot control system according to claim 7, characterized in that: The control system realizes motor driving torque adjustment by adjusting core control parameters of the motor, and specific parameters include feedforward torque In the hybrid control of the motor, the final output torque of the motor is calculated by a PD controller, and the formula is: ff Desired angular position p des Desired angular velocity ​ des， Position stiffness k p， Velocity stiffness k d , ​ The control system is based on the dynamics model of the planar five-bar mechanism, and through forward kinematics calculation and Jacobian matrix mapping, the required training impedance of the patient is converted into the driving torque executable by the motor, and the driving torque applied by the motor is changed to match the mid-late stage impedance training requirements of patients with different muscle strength levels.

9. The planar parallel mechanism based upper limb rehabilitation robot control system according to claim 8, characterized in that: The control system is based on the integrated motor control and force-position hybrid control mode to accurately adjust the impedance, and the force-position hybrid control mode is calculated through the kinematics model of the five-bar mechanism. In the kinematic model of the five-bar linkage, the lengths of the five links L 1 、 L 2 、 L 3 、 L 4 、 L 5 are known constants, and the angles of the two revolute pairs at A and E are driven by motors, whose angles Φ 1 、 Φ 4 are measured by the built-in encoders of the motors, Set Φ 2 As a connecting rod L 2 Acute angle with the horizontal line, Φ 3 As a connecting rod L 3 Obtuse angle with the horizontal line, The coordinates of point C, the end point of the five-bar linkage, are obtained through kinematic calculations and represented using rectangular coordinates (x, y). Assuming point A is located at the origin (0, 0), the coordinates of point E are (x, y). L 5 , 0); The coordinates of point B are given by Φ 1 The position equation of the drive The coordinates of point D are given by Φ 4 The position equation of the drive According to the five-bar closed condition, the C point coordinates are projected to the x axis and y axis through the left and right parts of the five-bar mechanism, and the position equation of the C point is obtained In the formulae was obtained. wherein is the distance from point B to point D; Simplify to linear combination form The system is Defining the auxiliary angle , the solution is According to Φ 2 The right angle coordinates of point C are calculated from the results Φ 3 The values of the coordinates of the point C are calculated by the following equations 。 10. The planar parallel mechanism based upper limb rehabilitation robot control system according to claim 8, wherein: The control system includes the following functions. Training parameter setting: support motion graphics, graphic size, training impedance setting; Data visualization: can real-time display the predetermined trajectory and actual motion trajectory of the end effector, hand thrust change curve, motor working state; Safety control: the emergency stop button in the form of software is arranged at the interactive interface, and the physical limit of the mechanical structure is matched, when the end effector exceeds the preset motion range or the motor temperature exceeds 40 DEG C, the training is automatically stopped and an alarm prompt is issued; Data storage: record the time, trajectory deviation, average thrust and motor state data of each training, which is convenient for therapists to evaluate the rehabilitation progress; The steps of the use process specifically include: The parameter setting step: set the trajectory to be executed by the end effector, select a certain motion graphics, input the size, and set the training impedance; The training start step: the motor outputs impedance according to the preset trajectory, the trajectory display area real-time draws the predetermined trajectory and actual trajectory, and the thrust change diagram displays the real-time thrust and set impedance; The data storage step.

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