Experimental rat hind limb platform type gait device and control method thereof

Abstract

The invention discloses an experimental rat hind limb platform type gait device and a control method thereof, and relates to the technical field of experimental animal behavior training and rehabilitation evaluation.The device comprises a fore limb positioning platform, a hind limb driving platform, a safety protection assembly, a data acquisition unit and a control unit; the control unit is used for generating an optimal track and driving the hind limb driving platform to move, specifically, target track parameters are set according to the injury state of the rat, the hind limb driving platform is started, multi-target optimization is conducted on the movement track of the hind limb driving platform based on the target track parameters, and meanwhile gait data of the rat are monitored in real time. When the gait data is abnormal, the hind limb driving platform is closed, and an alarm is given; according to the invention, individualized, intelligent and safe control of a rat gait training process can be realized, so that a motion track is adaptive to gait characteristics of different repair stages, and the accuracy of rehabilitation evaluation and the reliability of an experimental result are improved.

Description

Technical Field

[0001] This invention relates to the technical field of experimental animal behavior training and rehabilitation assessment, and more specifically, to an experimental rat hindlimb platform gait device and its control method. Background Technology

[0002] In the field of biomedical research, rodents, especially rats, are often used as model animals for Achilles tendon injury repair studies due to their high similarity to humans in physiological structure and the relative ease of experimental manipulation. Rehabilitation training after Achilles tendon injury is a crucial step in promoting tissue repair and restoring motor function, and precise training and dynamic assessment of hindlimb gait are key research focuses. However, existing devices and methods for hindlimb gait training in experimental rats still have significant shortcomings, specifically in the following aspects:

[0003] (1) The singularity and non-physiological nature of trajectory driving: Traditional hind limb gait training devices mostly rely on fixed speed treadmills or simple periodic driving (such as sine wave trajectory). Their movement patterns are significantly different from the natural gait of healthy rats, which seriously affects the reliability of experimental results.

[0004] (2) Passivity and limitations of safety protection mechanisms: Existing devices rely mainly on physical barriers (such as side limit bars) or passive braking to protect the movement safety of rats, lacking the ability to actively monitor and intervene in real time.

[0005] (3) Fixed training parameters and lack of stage adaptability: Achilles tendon injury repair is a phased dynamic process, usually divided into the inflammatory phase (0-7 days after injury), the proliferative phase (7-21 days), and the remodeling phase (more than 21 days). The requirements for gait training differ significantly at different stages: the inflammatory phase requires reducing interstitial pressure and avoiding overstimulation, requiring low amplitude (≤0.03m) and low frequency (0.5Hz) training; the proliferative phase requires promoting the orderly arrangement of collagen fibers, requiring a gradual increase in load (amplitude 0.05-0.07m, frequency 1-1.5Hz); the remodeling phase requires simulating normal movement patterns to restore function, requiring high amplitude (0.08-0.12m), high frequency (2-3Hz), and complex trajectories (such as changes of direction and speed). However, the training parameters of existing devices are mostly fixed or only support simple linear adjustment, and cannot automatically switch modes according to the repair stage, resulting in a mismatch between the training program and physiological needs, which directly affects the repair effect.

[0006] In summary, existing hindlimb gait training devices have shortcomings in terms of trajectory driving, safety protection, and parameter adaptation, making it difficult to meet the precise and personalized needs of research on Achilles tendon injury repair in experimental rats. Therefore, there is an urgent need to develop a novel device that combines intelligent control methods, multi-dimensional safety protection, and phased adaptive adjustment to improve the reliability and scientific rigor of experiments. Summary of the Invention

[0007] The purpose of this invention is to provide an experimental rat hindlimb platform gait device and its control method, which, through modular structural design, CHOMP algorithm-optimized trajectory generation, and real-time monitoring of multiple parameters, achieves precise driving, safety protection, and phased rehabilitation assessment of rat hindlimb gait.

[0008] The technical solution of the present invention is: a control method for an experimental rat hindlimb platform-type gait device, the device comprising a hindlimb drive platform and a data acquisition unit, the method comprising:

[0009] Step 1: Place the rat on the hind limb drive platform, fix its forelimbs, and make the soles of its hind limbs contact the upper surface of the hind limb drive platform so that the rat's hind limbs can drive the platform to move.

[0010] Step 2: Calibrate the data acquisition unit based on the rat's current location so that its detection range covers the rat's hind limb activity area;

[0011] Step 3: Set target trajectory parameters based on the rat's current injury state, activate the hind limb drive platform, and perform multi-objective optimization of the hind limb drive platform's motion trajectory based on the target trajectory parameters to ensure the platform moves along the optimal trajectory. This specifically includes:

[0012] Step 31: Construct a multi-objective cost function for trajectory optimization to quantify the smoothness, safety, and task adaptability of the trajectory;

[0013] Step 32: Define the initial trajectory and optimization constraints of the hind limb drive platform so that the hind limb drive platform moves according to the initial trajectory at the initial moment after startup;

[0014] Step 33: Set the target trajectory parameters according to the current injury state of the rat, iteratively adjust the motion trajectory of the hind limb drive platform, minimize the multi-objective cost function, and make the motion trajectory of the hind limb drive platform gradually approach the expected trajectory corresponding to the target trajectory parameters while satisfying the constraints, and finally obtain the optimal trajectory.

[0015] Step 34: Convert the optimal trajectory into a device control command, and use the control command to drive the hind limb drive platform to move along the optimal trajectory;

[0016] Step 4: Use the data acquisition unit to detect the rat's gait data, update the target trajectory parameters based on the gait data, and perform multi-objective optimization on the hind limb drive platform's motion trajectory again based on the updated target trajectory parameters. At the same time, monitor the rat's gait data in real time, and shut down the hind limb drive platform and issue an alarm when the gait data is abnormal.

[0017] Step 5: After reaching the preset exercise duration, turn off the hind limb drive platform and remove the rat.

[0018] Furthermore, step 31 specifically includes:

[0019] A smoothing term is constructed to penalize the acceleration of the hindlimb-driven platform. The smoothing term is represented as:

[0020] ;

[0021] In the formula, x(t) represents the motion trajectory of the hindlimb-driven platform. For the acceleration of the hind limb drive platform, Let t be the rate of change of acceleration, t be time, and t0 be the initial moment of motion. f The end of the exercise. and These are the weighting coefficients;

[0022] A safety term is constructed to constrain the speed and acceleration of the hindlimb drive platform. The safety term is represented as follows:

[0023] ;

[0024] In the formula, For the speed of the hind limb drive platform, The maximum speed of the hindlimb driven platform. This is the maximum acceleration of the hind limb drive platform;

[0025] Construct a task item to make the motion trajectory of the hind limb drive platform approximate the desired trajectory. The task item is represented as follows:

[0026] ;

[0027] In the formula, For the desired trajectory, For the desired velocity, k1 is the displacement error weighting coefficient, and k2 is the velocity error weighting coefficient;

[0028] The multi-objective cost function is obtained by weighting and superimposing the smoothing term, the safety term, and the task term:

[0029] ;

[0030] In the formula, w smooth For the weights of the smoothing term, w safe For the weight of the safety item, w task w represents the weight of the task item. smooth +w safe +w task =1.

[0031] Furthermore, the initial trajectory in step 32 is represented as:

[0032] ;

[0033] In the formula, T is the period of a single reciprocating motion of the hindlimb-driven platform, and 0.05 is the amplitude used to simulate the rat's stride length; the optimization constraints include: the maximum speed of the hindlimb-driven platform. =0.5m / s, Maximum acceleration =2m / s 2 , ; Travel range x min =-0.1m、x max =0.1m, x min ≤x≤x max ; Duration of a single movement t total =10s.

[0034] Furthermore, in step 33, the target trajectory parameters are set according to the current injury state of the experimental rat, specifically including:

[0035] Based on the rat's injury state, multiple motor control stages were defined, and corresponding target trajectory parameters were set for each motor control stage. The target trajectory parameter values ​​for multiple motor control stages were arranged in ascending order. Each target trajectory parameter included the amplitude A, period T, and smoothing term weight w of the trajectory. smooth Safety item weight w safe Task item weight w task The desired trajectory corresponding to the target trajectory parameters is represented as follows:

[0036] ;

[0037] In the formula, x des (t) represents the desired trajectory.

[0038] Furthermore, step 33 also includes the following steps:

[0039] Step 331: Use B-spline curves to represent the motion trajectory of the limb-driven platform 3. And by controlling vertex P i Define the shape of the motion trajectory to parameterize it, as follows:

[0040]

[0041] In the formula, Let P be a cubic B-spline basis function. i This represents the i-th control vertex, where i = 0, 1, 2, ..., n-1, and n-1 is the total number of control vertices in the motion trajectory.

[0042] Step 332, according to the control vertex corresponding to the preset initial trajectory Generate a parameterized initial trajectory, calculate the cost value corresponding to the initial trajectory based on the multi-objective cost function, and calculate the current cost value for the control vertex P using automatic differentiation. i The gradient is calculated, and then the control vertex P is adjusted in the opposite direction of the gradient. i In order to reduce the cost;

[0043] Step 333, based on the adjusted control vertex P i Generate a new motion trajectory, recalculate the cost value corresponding to the current motion trajectory based on the multi-objective cost function, and calculate the current cost value for the control vertex P using the automatic differentiation method. i The gradient is calculated, and then the control vertex P is adjusted in the opposite direction of the gradient. i Repeat this optimization process until the change in cost value is less than a preset threshold or the maximum number of iterations is reached, then stop iterating to obtain the optimal control vertex. ;

[0044] Step 334, based on the optimal control vertex Generate the optimal trajectory, which is close to the desired trajectory.

[0045] Furthermore, step 4 specifically includes:

[0046] The data acquisition unit includes a pressure sensor and a posture sensor. The pressure sensor collects the rat's hind limb extension force F, and the posture sensor collects the gait cycle corresponding to the rat's alternating hind limb extension movements. When the mean value of the extension force F is greater than the extension force threshold F within a predetermined time interval, the data acquisition unit is selected. threshold When the fluctuation range of the gait cycle is within the predetermined range, the target trajectory parameters are updated to the next motion control stage, and the motion trajectory of the hind limb drive platform is optimized again based on the updated target trajectory parameters. The rat's hind limb push-off force F and gait cycle are monitored in real time. When the fluctuation range of the hind limb push-off force F exceeds 20% or the fluctuation range of the gait cycle exceeds the predetermined range, the gait data is judged to be abnormal, the hind limb drive platform is shut down and an alarm signal is sent to the display module.

[0047] Furthermore, step 2 specifically includes:

[0048] The pressure sensor is encased in the transmission mechanism within the hind limb drive platform. Its position is adjusted so that its detection range covers all areas that the rat's hind limb can reach during movement. The posture sensor is mounted on one side of the transmission mechanism via a triangular bracket. Its position is adjusted so that its detection field of view faces the location of the rat's hind limb.

[0049] The technical solution of the present invention also provides an experimental rat hindlimb platform gait device for performing the above-mentioned experimental rat hindlimb platform gait device control method, the device comprising: a main support frame, a forelimb positioning platform, a hindlimb driving platform, a safety protection component, a data acquisition unit, and a control unit;

[0050] The hind limb drive platform is fixed above the main support frame to support the rat's hind limbs and provide them with walking drive force;

[0051] The forelimb positioning platform is fixed on the hindlimb driving platform, with a forelimb support plate in the middle. The forelimb support plate is located above the front side of the hindlimb driving platform and is used to fix the rat's forelimb.

[0052] The safety protection component includes two baffles, which are symmetrically fixed on the left and right sides of the hind limb drive platform to limit the range of lateral movement of the rat's body.

[0053] The control unit is electrically connected to the hindlimb drive platform and the data acquisition unit respectively. The data acquisition unit is used to collect gait data of the rat during movement. The control unit is used to optimize and generate the optimal trajectory based on the gait data and the desired trajectory, and use the optimal trajectory to drive the hindlimb drive platform to move.

[0054] Furthermore, the forelimb positioning platform also includes a position adjustment mechanism. The position adjustment mechanism consists of two support plates of the same shape, which are symmetrically fixed on the left and right sides of the front end of the hindlimb drive platform. A sliding groove is provided on the upper part of each support plate, and the sliding groove is connected to the end of the forelimb support plate to adjust the height of the forelimb support plate.

[0055] The safety protection components include a left limiting baffle and a right limiting baffle. The left and right limiting baffles are symmetrically fixed on the left and right sides of the front end of the hind limb drive platform to limit the lateral movement range of the rat's body. The longitudinal section of the left limiting baffle is Z-shaped, with vertical plates at the top and bottom and a horizontal plate in the middle. The lower vertical plate is vertically fixed to the front end of the left side of the hind limb drive platform, and the horizontal plate in the middle is parallel to the upper surface of the hind limb drive platform. The height of the upper vertical plate towards the upper edge of the hind limb drive platform is not less than the height of the rat's shoulder when standing. A limiting gap is reserved between the upper vertical plates of the left and right limiting baffles to accommodate the rat's body.

[0056] Furthermore, the hind limb drive platform includes a transmission mechanism, a drive motor, a guide roller, and a motor controller; the drive motor is fixed on the main support frame, and its output shaft is connected to the drive roller at the rear end of the transmission mechanism through the guide roller. The guide roller is used to transmit torque, and the drive motor is used to drive the transmission mechanism to reciprocate. The transmission mechanism is used to traction the rat's hind limbs to move; the motor controller is fixed on the main support frame and is used to adjust the output speed of the drive motor according to the control commands sent by the control unit.

[0057] The data acquisition unit includes a pressure sensor and an attitude sensor. The pressure sensor is wrapped around the conveyor belt of the conveying mechanism, and its detection area covers the range of motion of the rat's hind limb. The attitude sensor is set on one side of the conveying mechanism, and its detection field of view is directed towards the location of the rat's hind limb.

[0058] The beneficial effects of this invention are:

[0059] First, the technical solution of this invention introduces trajectory optimization computation into the control of the hindlimb drive platform. By constructing a multi-objective cost function containing smoothness, safety, and task terms, the motion trajectory of the hindlimb drive platform is iteratively optimized to achieve multi-objective results. This makes the trajectory smoother in dimensions such as acceleration, velocity, and relative displacement, gradually approaching the natural gait curve of rats. It can realistically simulate the physiological gait characteristics of healthy rats and significantly improve the physiological matching degree of training exercises. At the same time, this invention also sets corresponding target trajectory parameters according to different stages of rat Achilles tendon repair (such as the inflammatory phase, proliferative phase, and remodeling phase), and updates the target trajectory parameters in combination with the real-time acquisition results of gait data. It dynamically adjusts the exercise rhythm and load intensity, realizing a phased control strategy in which training parameters are automatically switched with the rehabilitation stage. This allows the gait training of the hindlimb drive platform to gradually progress from low load to high load, meeting the phased needs of the physiological repair process and conforming to the physiological laws of Achilles tendon repair. This provides a high-precision and intelligent experimental platform for Achilles tendon injury repair research.

[0060] Secondly, the technical solution of this invention uses posture sensors and pressure sensors to detect the gait characteristics of the rat's hind limbs (such as push-off force and gait cycle) in real time. When the detected data fluctuations exceed a preset threshold, the control unit automatically adjusts the trajectory parameters or stops the movement, achieving dynamic matching between training intensity and individual condition, avoiding excessive load and secondary injury, and ensuring the safety and scientific nature of animal experiments. In addition, the technical solution of this invention also sets up a safety protection component, including two baffles and a transparent protective cover. The two baffles can form an active safety constraint on the rat's movement area, and the transparent protective cover can form a closed training space to prevent the rat from jumping out or falling off the platform during training. Through the joint control of the safety protection component and different sensors, this invention realizes active monitoring and anti-fall protection of the rat's movement area. When the posture deviates or is abnormal, it can trigger the movement platform to stop automatically and provide an alarm prompt. Compared with the traditional passive limit structure, it significantly improves experimental safety and provides a reliable guarantee for long-term continuous training of animal experiments.

[0061] Third, the technical solution of this invention utilizes posture sensors and pressure sensors to collect gait information of rats in real time, including key parameters such as push-off force and gait cycle. The control unit dynamically analyzes the collected data. When the detection result deviates from the preset threshold range, the system automatically adjusts the movement trajectory parameters or pauses the training process, thereby forming a closed-loop feedback control mechanism based on individual gait status. The technical solution of this invention can dynamically adjust the movement rhythm and stride of the hind limb drive platform through this closed-loop feedback control mechanism, so that its driving force can be matched in real time with the changes in the rat's functional recovery level, realizing individualized training adjustment and improving the safety and adaptability of the training process, significantly improving the individualized accuracy and safety of training. Attached Figure Description

[0062] The advantages of the above and additional aspects of the present invention will become apparent and readily understood in the description of the embodiments in conjunction with the following drawings, wherein:

[0063] Figure 1 This is a schematic flowchart of a control method for an experimental rat hindlimb platform gait device according to an embodiment of the present invention;

[0064] Figure 2 This is a schematic diagram of the overall structure of an experimental rat hindlimb platform gait device according to an embodiment of the present invention.

[0065] Figure 3 This is a schematic diagram of the structure of a forelimb positioning platform and a hindlimb driving platform according to an embodiment of the present invention.

[0066] Among them, 1-main support frame, 2-forelimb positioning platform, 21-forelimb support plate, 22-position adjustment mechanism, 221-slide groove, 3-hindlimb drive platform, 31-transfer mechanism, 311-conveyor belt, 32-drive motor, 33-guide roller, 34-motor controller, 4-safety protection components, 41-left limit baffle, 42-right limit baffle, 5-data acquisition unit, 51-pressure sensor, 52-attitude sensor, 6-display module. Detailed Implementation

[0067] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0068] In the following description, many specific details are set forth in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0069] like Figure 1 As shown, this embodiment provides an experimental rat hindlimb platform gait device, which includes: a main support frame 1, a forelimb positioning platform 2, a hindlimb driving platform 3, a safety protection component 4, a data acquisition unit 5, and a control unit.

[0070] The hind limb drive platform 3 is fixed above the main support frame 1. The hind limb drive platform 3 is used to support the rat's hind limbs and provide them with walking drive force.

[0071] The forelimb positioning platform 2 is fixed on the hindlimb driving platform 3, with a forelimb support plate 21 in the middle. The forelimb support plate 21 is located above the front side of the hindlimb driving platform 3 and is used to fix the rat's forelimb.

[0072] The safety protection component 4 includes two baffles, which are symmetrically fixed on the left and right sides of the hind limb drive platform 3. The safety protection component 4 is used to limit the range of lateral movement of the rat's body.

[0073] The control unit is electrically connected to the hind limb drive platform 3 and the data acquisition unit 5 respectively. The data acquisition unit 5 is used to collect gait data of the rat during the movement process and feed the gait data back to the control unit. The control unit is used to optimize and generate the optimal trajectory based on the real-time gait data and the desired trajectory, and use the optimal trajectory to drive the hind limb drive platform 3 to move, so as to achieve precise control of the rat's hind limb movement.

[0074] The main support frame 1 is the basic support structure, used to support the overall structure including the forelimb positioning platform 2, the hindlimb driving platform 3 and the safety protection components 4.

[0075] The forelimb positioning platform 2 also includes a position adjustment mechanism 22, which is used to connect the forelimb support plate 21 and the hindlimb drive platform 3, and adjust the height of the forelimb support plate 21 so that the rat's forelimbs naturally overlap and are fixed above the forelimb support plate 21.

[0076] The position adjustment mechanism 22 is divided into two support plates of the same shape. Each support plate is inverted Y-shaped. The two support plates are symmetrically fixed on the left and right sides of the front end of the hind limb drive platform 3. A sliding groove 221 is provided on the upper part of each support plate. The sliding groove 221 is used to adjust the horizontal position of the forelimb support plate 21.

[0077] Connectors are provided at both ends of the forelimb support plate 21. These connectors have through holes that match the positions of the sliding grooves 221. The connectors at both ends of the forelimb support plate 21 are connected to the sliding grooves 221 on the two support plates respectively by bolts. When the horizontal position of the forelimb support plate 21 needs to be adjusted, the bolts are loosened, and the forelimb support plate 21 is moved up and down along the sliding grooves 221 until it reaches the preset position. Then, the bolts are tightened to achieve position adjustment and fixation of the forelimb support plate 21. Anti-slip textures are provided on the middle surface of the forelimb support plate 21 to increase friction when fixing the rat's forelimb, preventing the rat from struggling, shifting, or slipping.

[0078] In this embodiment, the forelimb support plate 21 and the position adjustment mechanism 22 can be made of acrylic or stainless steel.

[0079] The hind limb drive platform 3 includes a transmission mechanism 31, a drive motor 32, and a guide roller 33.

[0080] The drive motor 32 is fixed on the main support frame 1 below the hind limb drive platform 3. The output shaft of the drive motor 32 is connected to the active roller (i.e., the rotatable shaft at the end of the conveyor belt) at the rear end of the conveyor mechanism through the guide roller 33. The guide roller 33 is used to transmit the torque of the drive motor 32 and drive the active roller to rotate. The drive motor 32 is used to drive the conveyor belt 311 in the conveyor mechanism 31 to reciprocate in a set direction through the guide roller 33 (that is, to make the conveyor belt perform cyclical motion). The conveyor mechanism 31 is used to support the hind limbs of the rat and to guide the hind limbs to walk autonomously or be passively driven to achieve hind limb gait training. The surface of the conveyor belt 311 in the drive conveyor mechanism 31 is also provided with anti-slip texture. The anti-slip texture is used to increase the friction between the hind limbs of the rat and the conveyor belt 311 to prevent the animal's hind limbs from slipping or stepping into the air during the movement, thereby ensuring the stability and effectiveness of the hind limb gait training process.

[0081] In this embodiment, the conveying mechanism 31 can force the rat's hind limbs to alternately extend and push with the conveyor belt. When the rat's hind limbs contact the surface of the conveyor belt, the buffer pad layer in the conveying mechanism 31 can provide elastic support to simulate the ground reaction force of natural gait.

[0082] The hind limb drive platform 3 also includes a motor controller 34, which is fixed on the main support frame 1 below the hind limb drive platform 3 and electrically connected to the drive motor 32. The motor controller 34 is used to adjust the output speed of the drive motor 32 according to the control command sent by the control unit, so as to realize the speed adjustment and motion mode control of the transmission mechanism 31 and ensure the controllability of the rat hind limb gait training process.

[0083] The safety protection component 4 includes a left limiting baffle 41 and a right limiting baffle 42. The left limiting baffle 41 and the right limiting baffle 42 are symmetrically fixed on the left and right sides of the front end of the hind limb drive platform 3 to limit the range of lateral movement of the rat's body, prevent the animal from deviating from the training trajectory or slipping off the training platform, avoid accidental injury, and improve training safety.

[0084] The longitudinal section of the left limiting baffle 41 is Z-shaped, with vertical plates at the top and bottom and a horizontal plate in the middle. The lower vertical plate is vertically fixed to the front end of the left side of the hind limb drive platform 3, and the horizontal plate in the middle is parallel to the upper surface of the hind limb drive platform 3. The upper vertical plate extends to the right side of the hind limb drive platform 3, and the height of its upper edge is not lower than the height of the rat's shoulder when standing, which can form a limiting constraint on the side of the rat's body. The right limiting baffle 42 has the same shape and symmetrical position as the left limiting baffle 41. A limiting gap of a set width is reserved between the upper vertical plate of the left limiting baffle 41 and the upper vertical plate of the right limiting baffle 42 to accommodate the rat's body and provide it with a controllable lateral movement space, which can prevent the animal from falling to the side without affecting its natural hind limb swing and walking posture.

[0085] The way the right limit baffle 42 is fixedly connected to the rear limb drive platform 3 is the same as that of the left limit baffle, which will not be described in detail here.

[0086] The safety protection component 4 also includes a transparent protective cover, which is arranged around the outside of the hind limb drive platform 3 and has an opening at the top for the rat to enter. The transparent protective cover is used to form a closed training space to prevent the rat from jumping out or falling off the outside of the platform during training.

[0087] In this embodiment, the transparent protective cover can be made of rigid plastic or glass to avoid obstructing the data acquisition unit 5 from collecting the rat's gait data, while also facilitating researchers to observe the rat's movement behavior and gait status from the outside.

[0088] The data acquisition unit 5 includes a pressure sensor 51 and an attitude sensor 52.

[0089] The pressure sensor 51 is covered on the conveyor belt 311 and is located in the target detection area below the left limiting baffle 41 and the right limiting baffle 42. This target detection area covers the range of movement trajectory of the rat's hind limb during training. The pressure sensor 51 is used to detect the pressure data of the rat's hind limb on the conveyor mechanism 31.

[0090] The posture sensor 52 is mounted on one side of the conveying mechanism 31 via a triangular bracket, and its detection field of view is directed toward the location of the rat's hind limb. The posture sensor 52 is used to collect gait data of the rat's hind limb, including hind limb cadence, stride length, support duration, and joint range of motion, in order to help evaluate the gait training effect.

[0091] The experimental rat hindlimb platform gait device also includes a display module 6, which is communicatively connected to the pressure sensor 51, the posture sensor 52 and the control unit, respectively. The display module 6 is used to configure the target trajectory parameters for the control unit, record and display the pressure data fed back by the pressure sensor 51, the gait data fed back by the posture sensor 52 and the control commands output by the control unit in real time, and generate a training report.

[0092] In this embodiment, the display module 6 can be a computing terminal with display and data processing functions, such as a host computer, to realize data visualization, training process monitoring, parameter configuration, and analysis result output.

[0093] It should be noted that the experimental rat hindlimb platform gait device of the present invention is applicable to rodents, and rats are used as an example in this embodiment.

[0094] like Figure 1 As shown, this embodiment also provides a control method for an experimental rat hindlimb platform gait device, the method comprising:

[0095] Step 1: Place the rat on the hind limb drive platform 3, adjust the forelimb support plate 21 to the preset height, and fix the rat's forelimb to the forelimb support plate 21 so that the bottom of the rat's hind limb foot contacts the upper surface of the hind limb drive platform 3, so that the rat's hind limb can move on the surface of the hind limb drive platform 3.

[0096] Specifically, the main support frame 1 is fixed on a horizontal operating plane, the rat is placed between the two baffles of the safety protection component 4, the height of the forelimb support plate 21 is adjusted and kept horizontal so that it is consistent with the height of the forelimb when the rat is walking upright, and then the rat's forelimb is gently placed on the adjusted forelimb support plate 21 and fixed, so that the bottom of the rat's hind limb foot contacts the upper surface of the transmission mechanism 31 in the hind limb drive platform 3, allowing the rat to walk only on its hind limbs, and the two baffles of the safety protection component 4 are used to limit the range of lateral movement of the rat's body to prevent the rat from falling.

[0097] It should be noted that before training begins, the forelimb height of the selected experimental rats can be measured to obtain the forelimb height when the rats walk upright, and this height can be set as the preset height. The forelimb support plate 21 can be adjusted to match the rat's natural walking posture.

[0098] Step 2: Based on the current location of the rat, calibrate the pressure sensor 51 and posture sensor 52 so that the detection range of the pressure sensor 51 and posture sensor 52 covers the activity area of ​​the rat's hind limbs, thereby ensuring that the pressure sensor 51 and posture sensor 52 can accurately collect the pressure data and gait data of the rat during movement.

[0099] Specifically, the pressure sensor 51 is wrapped around the conveyor belt 311 and its position is adjusted so that its detection range covers all areas that the rat's hind limbs can reach when they move. The posture sensor 52 is set on one side of the conveyor mechanism 31 by a triangular bracket and its position is adjusted so that its detection field of view faces the location of the rat's hind limbs, thereby covering the actual activity area of ​​the rat's hind limbs and improving detection accuracy.

[0100] Step 3: Set the target trajectory parameters based on the rat's current injury state, start the hind limb drive platform 3, and use the control unit to perform multi-objective optimization of the hind limb drive platform 3's motion trajectory based on the target trajectory parameters, so that the hind limb drive platform 3 moves along the optimal trajectory. Specifically, this includes:

[0101] Step 31: Construct a multi-objective cost function for trajectory optimization of the hind limb drive platform 3 to quantify the smoothness, safety and task adaptability of the trajectory. The multi-objective cost function includes a smoothness term, a safety term and a task term.

[0102] Specifically, a smoothing term is constructed based on the acceleration of the hind limb drive platform 3 to penalize excessively large accelerations. The smoothing term is expressed as follows:

[0103]

[0104] In the formula, x(t) is the motion trajectory of the hind limb drive platform (which is a function of the relative displacement of the hind limb drive platform 3 with respect to time, and the relative displacement is the offset of a point of the hind limb drive platform 3 relative to the reference position). For the acceleration of the hind limb drive platform, Let t be the rate of change of acceleration, t be time, and t0 be the initial moment of motion (i.e., the moment when the hindlimb-driven platform 3 begins to move). f The endpoint of the motion (i.e., the moment when the hindlimb drive platform 3 ends its motion), t0 and t f These are the endpoints of the time interval, used to define the time range of multi-objective costs. and Here, are the weighting coefficients, =1, =0.5, where the weighting coefficient can be adjusted during calculation. and Normalize.

[0105] A safety term is constructed based on the velocity and acceleration of the hindlimb drive platform to constrain its velocity and acceleration. The safety term is expressed as follows:

[0106]

[0107] In the formula, For the speed of the hind limb drive platform, The maximum speed of the hindlimb driven platform. This represents the maximum acceleration of the hindlimb drive platform; where, , =0.5m / s, , =2m / s 2 .

[0108] Based on the displacement and velocity of the hindlimb-driven platform, a task is constructed to make the motion trajectory of the hindlimb-driven platform approach the desired trajectory corresponding to the target trajectory parameters. The task is represented as follows:

[0109]

[0110] In the formula, For the desired trajectory, Let k1 be the desired velocity (i.e., the derivative of the desired trajectory), k2 be the displacement error weighting coefficient used to control the influence of displacement error on the cost function in the task item, and k3 be the velocity error weighting coefficient used to control the influence of velocity error on the cost function in the task item. Here, k1=2 and k2=1.

[0111] By weighting and superimposing the smoothing term, safety term, and task term, we obtain the multi-objective cost function, expressed as:

[0112]

[0113] In the formula, w smooth For the weights of the smoothing term, w safe For the weight of the safety item, w task , where w represents the task weights, used to balance the relative importance of each optimization objective in the multi-objective cost function. smooth +w safe +w task =1.

[0114] In this embodiment, w smooth w safe w task The value can be set according to actual needs. For example, if the main focus is on the stability and safety of the trajectory, w can be set to... smooth =0.6, w safe =0.3, w task =0.1. The smoothing term penalizes abrupt changes in trajectory acceleration / jerk (ensuring smoothness), the safety term penalizes regions of overspeed / acceleration (ensuring safety), and the task term penalizes deviations from the desired gait (ensuring task effectiveness).

[0115] Step 32: Define the initial trajectory and optimization constraints of the hind limb drive platform 3 so that the hind limb drive platform 3 can move according to the initial trajectory at the initial moment after startup. The initial trajectory of the hind limb drive platform 3 is expressed as:

[0116]

[0117] In the formula, T is the period of a single reciprocating motion of the hind limb driving platform 3, T=2s, and the amplitude A is 0.05m, which is used to simulate the stride length of a rat.

[0118] The optimization constraints include: the maximum speed of the hind limb drive platform. =0.5m / s, Maximum acceleration of the hind limb drive platform =2m / s 2 , The travel range x of the hind limb drive platform min =-0.1m、x max =0.1m, x min ≤x≤x max ; Duration of a single movement t total =10s.

[0119] It should be noted that setting the travel range of the hind limb drive platform is to define its boundaries and constrain the system's range of motion during subsequent optimization processes, so as to prevent the generated motion trajectory from exceeding the set physical limits. Through this constraint, the system can ensure that the movement of the hind limb drive platform is carried out within a safe and effective range, thereby improving the stability of gait training.

[0120] Step 33: Set the target trajectory parameters according to the current injury state of the rat, and iteratively adjust the motion trajectory of the hind limb drive platform 3 through the Chomp algorithm to minimize the multi-objective cost function, so that the motion trajectory of the hind limb drive platform 3 gradually approaches the expected trajectory corresponding to the target trajectory parameters while satisfying the constraints, and finally obtains the optimal trajectory.

[0121] The target trajectory parameters are set based on the current injury status of the experimental rats, specifically including:

[0122] Based on the injury state of the experimental rats, multiple motor control stages were defined, and corresponding target trajectory parameters (each parameter corresponding to a specific value) were set for each motor control stage. The target trajectory parameter values ​​for multiple motor control stages were arranged in ascending order. A single target trajectory parameter includes the amplitude A, period T, and smoothing term weight w of the motion trajectory. smooth Safety item weight w safe Task item weight w task The desired trajectory corresponding to the target trajectory parameters is represented as follows:

[0123]

[0124] In the formula, x des (t) represents the desired trajectory.

[0125] It should be noted that by setting multiple motion control stages, this invention can flexibly adjust the motion characteristics of the hind limb drive platform according to the degree of injury, repair process and experimental requirements of the experimental rats, thereby improving trajectory tracking accuracy, enhancing motion smoothness, ensuring platform operation safety, and achieving phased adaptation to different time state requirements.

[0126] In practice, multiple motor control phases can be set according to the Achilles tendon injury status of the experimental rats. Each motor control phase can have different target trajectory parameters. For example, the motor control phase corresponding to the inflammatory phase can be set with amplitude A = 0.03m, frequency f = 0.5Hz, and weight w. smooth =0、w task =0.3、w safe =0.7; The motion control stage corresponding to the proliferation period is set with amplitude A=0.05m, frequency f=1Hz, and weight w. smooth =0、w task =0.5, w safe =0.5; The motion control stage corresponding to the remodeling period is set with amplitude A=0.07m, frequency f=1.5Hz, and weight w. smooth =0、w task =0.7, w safe =0.3.

[0127] The motion trajectory of the hind limb drive platform 3 is iteratively adjusted using the Chomp algorithm to minimize the multi-objective cost function, specifically including the following steps:

[0128] Step 331: Use B-spline curves to represent the motion trajectory of the limb-driven platform 3. And by controlling vertex P i (Optimizable anchor points, used to determine the shape of the curve) Define the shape of the motion trajectory, parameterize the motion trajectory, and represent it as:

[0129]

[0130] In the formula, Let P be a cubic B-spline basis function, representing the weight function corresponding to each control vertex, which varies with time t. i This represents the i-th control vertex; where i = 0, 1, 2, ..., n-1, and n-1 is the total number of control vertices in the motion trajectory.

[0131] It should be noted that parameterizing the motion trajectory is to enable the system to effectively identify the motion trajectory, so as to precisely adjust the shape of the motion trajectory by optimizing the position of these control vertices, thereby achieving precise control.

[0132] Step 332, according to the control vertex corresponding to the preset initial trajectory Generate a parameterized initial trajectory (i.e., a recognizable motion trajectory that meets the system input requirements), calculate the cost value corresponding to the initial trajectory based on a multi-objective cost function, and calculate the current cost value for the control vertex P using an automatic differentiation method. i The gradient (used to indicate the adjustment direction) is then used by the optimizer to adjust the control vertex P in the opposite direction of the gradient. i In order to reduce the cost.

[0133] Step 333, based on the adjusted control vertex P i Generate a new motion trajectory, recalculate the cost value corresponding to the current motion trajectory based on the multi-objective cost function, and calculate the current cost value for the control vertex P using the automatic differentiation method. i The gradient is calculated, and then the optimizer is used to adjust the control vertex P in the opposite direction of the gradient. i Repeat this optimization process until the change in cost is less than a preset threshold (the change in cost). Alternatively, after reaching the maximum number of iterations (e.g., 100), stop iterating to obtain the optimal control vertex. .

[0134] It should be noted that the Automatic Differentiation (AD) method used in this embodiment is an efficient and accurate method for calculating gradients, commonly used in deep learning, optimization problems, and other fields. An optimizer is a tool in an optimization algorithm used to adjust control vertices (or model parameters) to minimize the objective function. They iteratively adjust parameters (such as control vertices, weights, etc.) to gradually reduce the objective function, eventually converging to the optimal solution. In this embodiment, the optimizer can be Adam (an optimization algorithm widely used in deep learning and machine learning).

[0135] Step 334, based on the optimal control vertex Generate the optimal trajectory, which is close to the expected trajectory corresponding to the target trajectory parameters.

[0136] Step 34: Convert the optimal trajectory into control commands for the motor driver, and use these control commands to drive the hind limb drive platform 3 to move along the optimal trajectory.

[0137] Specifically, the optimal trajectory is discretized according to a preset sampling frequency (e.g., 100Hz) to obtain discrete trajectory data, where each sampling time tk Corresponding to a set of relative displacements x(t) k ), velocity v(t) k ) and acceleration a(t) k The information is used to perform cubic spline interpolation on discrete trajectory data to generate a continuous and smooth trajectory x. opt (t), based on the trajectory x opt (t) Calculate velocity and acceleration, expressed as:

[0138]

[0139]

[0140] x opt (t), v opt (t), a opt (t) Generate control commands as control information, and send these control commands to the motor controller via the CAN bus. The format of the control commands is: trajectory x opt (t), velocity v opt (t), acceleration a opt (t); The relative displacement of the hind limb drive platform 3 is updated in real time by the motor controller at a predetermined sampling interval Δt=0.01s, so that the hind limb drive platform 3 moves along the optimal trajectory.

[0141] In this embodiment, the hind limb drive platform 3 can be a commonly used transmission mechanism, which is equipped with a multi-stage speed-changing gear set, enabling stepless speed regulation from 0.1m / s to 2.0m / s.

[0142] It should be noted that the target trajectory parameters set for each motion control stage can be pre-input into the control unit via the display module 6 for storage. When in use, they can be directly selected via the display module 6 or read and selected by the control unit during updates.

[0143] Step 4: Use the data acquisition unit 5 to detect the gait data of the rats, update the target trajectory parameters based on the gait data, and perform multi-objective optimization on the movement trajectory of the hind limb drive platform 3 again based on the updated target trajectory parameters. This enables the hind limb drive platform 3 to adaptively adjust the movement trajectory according to the actual state of different rats, realize individualized gait training, and monitor the gait data of the rats in real time. When the gait data is abnormal, the hind limb drive platform 3 is shut down and an alarm is triggered.

[0144] Data acquisition unit 5 includes a pressure sensor 51 and a posture sensor 52. The pressure sensor 51 is used to collect the rat's hind limb extension force F, and the posture sensor 52 is used to collect the gait cycle corresponding to the rat's alternating hind limb extension movements. When the average value of the extension force F is greater than the extension force threshold F within a predetermined time interval, the data acquisition unit is selected. thresholdWhen the fluctuation range of the gait cycle is within the predetermined range, the target trajectory parameters are updated to the next motor control stage, and the motion trajectory of the hind limb drive platform 3 is optimized again based on the updated target trajectory parameters. The optimization method is the same as the optimization method in steps 331 to 334, and will not be described again here. This enables the hind limb drive platform 3 to adaptively adjust its motion trajectory based on the actual state of the experimental rat, so as to adapt to individual differences or changes in the rehabilitation stage of the rat.

[0145] The rat's hind limb push-off force F and gait cycle are monitored in real time. When the fluctuation range of the hind limb push-off force F exceeds 20% or the fluctuation range of the gait cycle exceeds the predetermined range, the gait data is judged to be abnormal, the hind limb drive platform 3 is shut down, and an alarm signal is sent to the display module 6. The target trajectory parameters are then prompted to be adjusted through the interface of the display module 6.

[0146] In this embodiment, the rat's hind limb extension force F refers to the force applied to the pressure sensor 51 when the rat pushes off the ground or takes a step using its hind limbs during movement. This force is generated when the rat pushes off the ground with its hind limbs during running, walking, or crawling, and can be detected by the pressure sensor 51. The gait cycle refers to the time period required for the rat to complete a full stride, which can be monitored by the posture sensor 52. When the rat walks normally, the gait cycle is stable, and the fluctuation amplitude remains within a predetermined range. When the rat does not walk normally, the fluctuation amplitude will exceed this range. For example, if the rat's hind limb extension is missing, the gait cycle may become abnormal, causing the gait to change to a dragging phase.

[0147] Step 5: After reaching the preset exercise duration, turn off the hind limb drive platform 3 and remove the rat.

[0148] Specifically, after reaching the preset exercise duration, a single or phased training session is completed. First, the hind limb drive platform 3 is turned off, and the rat is carefully removed. Then, the forelimb positioning platform 2, hind limb drive platform 3, and safety protection components 4 are cleaned and disinfected, and each component is reset to its initial position. The power to the data acquisition unit 5 and the control unit 5 is turned off.

[0149] It should be noted that gait data is collected in real time, but the target trajectory parameters can be updated at preset time intervals based on this real-time gait data. The specific update cycle is determined according to actual needs. The updated target trajectory parameters will be used to perform multi-objective optimization of the movement trajectory of the hindlimb drive platform 3, so that the platform movement can adapt to the actual state of different rats, automatically adjust the movement rhythm and stride, realize individualized gait guidance and load adaptive control, thereby improving the targeting of training and rehabilitation efficiency.

[0150] In this embodiment, during rat training, gait information such as hind limb cadence, stride length, support duration, and joint range of motion can be recorded. After each preset training period, an analysis report containing motion trajectory maps and mechanical parameters is generated based on this gait information to provide relevant materials for researchers to assess the progress of Achilles tendon injury repair. The gait information is collected at a frequency of no less than 100Hz, and the analysis report includes comparative analysis results with a healthy rat gait database, which can be used to quantitatively assess the degree of recovery of hind limb motor function in rats after Achilles tendon injury.

[0151] In this embodiment, experimental animals are typically 10-12 week old male SD rats, housed in an SPF-grade laboratory at the experimental center's animal facility. The laboratory holds an experimental animal use license issued by the relevant administrative authority, meeting the conditions for conducting the corresponding animal experiments. The SPF-grade rat animal laboratory (barrier environment) maintains a constant temperature (22°C), humidity, and a 12-hour light-dark cycle, allowing free access to food and water. Animal experimental procedures are strictly conducted in accordance with international animal welfare ethics and national health research institution guidelines regarding the care and use of laboratory animals, and have obtained approval from the animal welfare ethics review committee.

[0152] The steps in this invention can be adjusted, combined, or deleted according to actual needs.

[0153] The units in the device of the present invention can be merged, divided, or reduced according to actual needs.

[0154] In this invention, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.

[0155] The shapes of the components in the accompanying drawings are schematic and may differ from their actual shapes. The drawings are only used to illustrate the principles of the present invention and are not intended to limit the present invention.

[0156] Although the invention has been disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and not intended to limit the application of the invention. The scope of protection of the invention is defined by the appended claims and may include various modifications, alterations, and equivalents made to the invention without departing from the scope and spirit of the invention.

Claims

1. A control method of a platform-type gait device for the hind limbs of a laboratory rat, characterized by, The device comprises a hind limb driving platform (3) and a data acquisition unit (5), and the method comprises the following steps: Step 1: Place the rat on the hind limb driving platform (3), fix its forelimbs, and make the hind limb sole contact the upper surface of the hind limb driving platform (3) so that the rat hind limb can move with the hind limb driving platform (3); Step 2: Calibrate the data acquisition unit (5) based on the current position of the rat so that the detection range covers the rat hind limb activity area; Step 3: Set the target trajectory parameters according to the current injury state of the rat, start the hind limb driving platform (3), and perform multi-objective optimization on the motion trajectory of the hind limb driving platform (3) based on the target trajectory parameters so that the limb driving platform (3) moves along the optimal trajectory, which specifically comprises: Step 31: Construct a multi-objective cost function for trajectory optimization to quantify the smoothness, safety, and task adaptability of the trajectory; Step 32: Define the initial trajectory of the hind limb driving platform (3) and the optimization constraint condition so that the hind limb driving platform (3) moves according to the initial trajectory at the starting time after starting; Step 33: Set the target trajectory parameters according to the current injury state of the rat, iteratively adjust the motion trajectory of the hind limb driving platform (3), minimize the multi-objective cost function, and make the motion trajectory of the hind limb driving platform (3) gradually approach the expected trajectory corresponding to the target trajectory parameters under the condition of meeting the constraint condition, and finally obtain the optimal trajectory; Step 34: Convert the optimal trajectory into device control instructions, and drive the hind limb driving platform (3) to move along the optimal trajectory using the control instructions; Step 4: Detect the gait data of the rat using the data acquisition unit (5), update the target trajectory parameters based on the gait data, and perform multi-objective optimization on the motion trajectory of the hind limb driving platform (3) again based on the updated target trajectory parameters, while monitoring the gait data of the rat in real time, and when the gait data is abnormal, the hind limb driving platform (3) is turned off and an alarm is given; Step 5: After reaching the preset motion time, turn off the hind limb driving platform (3) and remove the rat.

2. The control method of the experimental rat hindlimb platform gait apparatus according to claim 1, wherein The step 31 specifically comprises: Construct a smoothing term to punish the acceleration of the hind limb driving platform (3), and the smoothing term is represented as: ； where x(t) is the trajectory of the hind limb driving platform, is the acceleration of the hind limb driving platform, is the acceleration rate, t is time, t0 is the starting time of the movement, f is the end time of the movement, and is the weight coefficient; Construct a safety term to constrain the speed and acceleration of the hind limb driving platform, and the safety term is represented as: ； wherein is the velocity of the hind limb drive platform, is the maximum velocity of movement of the hind limb drive platform, is the maximum acceleration of the hind limb drive platform; Construct a task term to make the motion trajectory of the hind limb driving platform approach the expected trajectory, and the task term is represented as: ； In the formula, is a desired trajectory, is a desired velocity, k1 is a displacement error weight coefficient, and k2 is a velocity error weight coefficient. Weight and superimpose the smoothing term, the safety term, and the task term to obtain the multi-objective cost function: ； where w smooth is a smoothness term weight, w safe is a safety term weight, w task is a task term weight, w smooth +w safe +w task = 1.

3. The method of controlling a rat hindlimb platform for gait analysis as claimed in claim 2, wherein, The initial trajectory in the step 32 is represented as: ； In the formula, T is the cycle of single reciprocating motion of the hind limb driving platform (3), 0.05 is the amplitude, and the amplitude is used for simulating the stride of the rat; the optimization constraint conditions include: the maximum speed of the hind limb driving platform =0.5m / s, ; the maximum acceleration =2m / s 2 , ; the stroke range x min =-0.1m, x max =0.1m, x min ≤x≤x max ; and the single motion duration t total =10s.

4. The control method of the rat hindlimb platform gait apparatus for experiments according to claim 3, wherein In the step 33, the target trajectory parameters are set according to the current injury state of the experimental rat, which specifically comprises: According to the injury state of the rat, a plurality of motion control stages are divided, corresponding target trajectory parameters are set for each motion control stage, the target trajectory parameter values corresponding to the plurality of motion control stages are arranged in a small-to-large manner, and a single target trajectory parameter includes an amplitude A, a period T, and a smoothing term weight w of a motion trajectory smooth , a safety term weight w safe , a task term weight w task ; the expected trajectory corresponding to the target trajectory parameter is represented as ； wherein x des (t) is the desired trajectory.

5. The method of claim 4, wherein the method further comprises: determining a current position of the platform; and determining a target position of the platform based on the current position of the platform. The step 33 further comprises the following steps: Step 331, the motion trajectory of the limb driving platform 3 is expressed by a B-spline curve and the vertex P i The shape of the motion trajectory is defined, and the motion trajectory is parameterized and expressed as: ； wherein is a cubic B-spline basis function, P i represents the i-th control vertex, i = 0, 1, 2,..., n-1, n-1 is the total number of control vertices of the motion trajectory; Step 332, adjusting the control vertex corresponding to the preset initial trajectory according to the preset initial trajectory generating a parameterized initial trajectory, calculating a generation value corresponding to the initial trajectory based on a multi-objective cost function, calculating a gradient of the current generation value with respect to the control vertex P i by automatic differentiation method, and then adjusting the control vertex P i in the opposite direction of the gradient to reduce the cost; Step 333, based on the adjusted control vertex P i Generate a new motion trajectory, recalculate the cost value corresponding to the current motion trajectory based on the multi-objective cost function, and calculate the current cost value for the control vertex P using the automatic differentiation method. i The gradient is calculated, and then the control vertex P is adjusted in the opposite direction of the gradient. i Repeat this optimization process until the change in cost value is less than a preset threshold or the maximum number of iterations is reached, then stop iterating to obtain the optimal control vertex. ; Step 334, based on the optimal control vertex An optimal trajectory is generated, which approaches the desired trajectory.

6. The method of claim 1, wherein the method further comprises: determining a current position of the platform; and determining a target position of the platform based on the current position of the platform. The step 4 specifically comprises: The data acquisition unit (5) comprises a pressure sensor (51) and a posture sensor (52), the pressure sensor (51) is used to collect the rat hind limb extension force F, and the posture sensor (52) is used to collect the gait cycle corresponding to the alternating extension action of the rat hind limb; when the mean value of the extension force F is greater than the extension force threshold F threshold in a predetermined time interval, and the fluctuation amplitude of the gait cycle is in a predetermined range, the target trajectory parameters are updated to the next motion control stage, and the motion trajectory of the hind limb driving platform (3) is optimized again based on the updated target trajectory parameters; the rat hind limb extension force F and the gait cycle are monitored in real time, when the fluctuation amplitude of the extension force F exceeds 20% or the fluctuation amplitude of the gait cycle exceeds the predetermined range, it is determined that the gait data is abnormal, the hind limb driving platform (3) is closed, and an alarm signal is sent to the display module (6).

7. The method of claim 6, wherein the method further comprises: determining a position of the platform; and adjusting the position of the platform based on the determined position of the platform. The step 2 specifically comprises: The pressure sensor (51) is wrapped on the conveying mechanism (31) in the hind limb driving platform (3), and its position is adjusted so that its detection range covers all areas that can be contacted by the rat hind limb during movement, and the attitude sensor (52) is arranged on one side of the conveying mechanism (31) through a triangular support, and its position is adjusted so that its detection field is directed towards the position of the rat hind limb.

8. A rat hindlimb platform gait apparatus for use in experiments, characterized in that The device is used for executing the control method of the experimental rat hindlimb platform gait device as claimed in any one of claims 1-7, and the device comprises: a main body support frame (1), a forelimb positioning platform (2), a hindlimb driving platform (3), a safety protection assembly (4), a data acquisition unit (5), and a control unit; The hindlimb driving platform (3) is fixed above the main body support frame (1) and is used for supporting the hindlimb of the rat and providing walking driving force for the rat; The forelimb positioning platform (2) is fixed on the hindlimb driving platform (3), and a forelimb support plate (21) is arranged in the middle of the forelimb positioning platform (2) and is located above the front side of the hindlimb driving platform (3) and is used for fixing the forelimb of the rat; The safety protection assembly (4) comprises two baffle plates which are symmetrically fixed on the left and right sides of the hindlimb driving platform (3) and are used for limiting the lateral movement range of the body of the rat; The control unit is electrically connected with the hindlimb driving platform (3) and the data acquisition unit (5), the data acquisition unit (5) is used for acquiring gait data of the rat in the movement process, and the control unit is used for generating an optimal trajectory according to the gait data and an expected trajectory and driving the hindlimb driving platform (3) to move by using the optimal trajectory.

9. The method of claim 8, wherein the method further comprises: determining a current position of the platform; and determining a target position of the platform based on the current position of the platform. The forelimb positioning platform (2) further comprises a position adjusting mechanism (22), the position adjusting mechanism (22) is divided into two support plates which are symmetrically fixed on the left and right sides of the front end of the hindlimb driving platform (3) and are identical in shape, an upper portion of each support plate is provided with a sliding groove (221), the sliding groove (221) is connected with an end portion of the forelimb support plate (21), and the height of the forelimb support plate (21) is adjusted by the sliding groove (221); The safety protection assembly (4) comprises a left limiting baffle (41) and a right limiting baffle (42), the left limiting baffle (41) and the right limiting baffle (42) are symmetrically fixed on the left and right sides of the front end of the hindlimb driving platform (3) and are used for limiting the lateral movement range of the body of the rat; a longitudinal section of the left limiting baffle (41) is in a Z shape, the upper and lower ends of the left limiting baffle (41) are vertical plates, and the middle part of the left limiting baffle (41) is a horizontal plate, the vertical plate at the lower end is fixed vertically on the front end of the left side of the hindlimb driving platform (3), the horizontal plate at the middle part is parallel to the upper surface of the hindlimb driving platform (3), the vertical plate at the upper end is higher than the shoulder of the rat when standing, and a limiting spacing is reserved between the vertical plate at the upper end of the left limiting baffle (41) and the vertical plate at the upper end of the right limiting baffle (42) and is used for accommodating the body of the rat.

10. The method of claim 8, wherein the method further comprises: determining a current position of the platform; and determining a target position of the platform based on the current position of the platform. The hindlimb driving platform (3) comprises a conveying mechanism (31), a driving motor (32), a guide roller (33), and a motor controller (34); the driving motor (32) is fixed on the main body support frame (1), an output shaft of the driving motor (32) is in transmission connection with a driving roller at the rear end of the conveying mechanism (31) through the guide roller (33), the guide roller (33) is used for transmitting torque, the driving motor (32) is used for driving the conveying mechanism (31) to move reciprocatingly, the conveying mechanism (31) is used for pulling the hindlimb of the rat to move; and the motor controller (34) is fixed on the main body support frame (1) and is used for adjusting the output rotating speed of the driving motor (32) according to the control instruction sent by the control unit. The data acquisition unit (5) comprises a pressure sensor (51) and a posture sensor (52), the pressure sensor (51) is coated on the conveying belt of the conveying mechanism (31), and a detection area of the pressure sensor (51) covers a movement range of the hind limbs of the rat; the posture sensor (52) is arranged on one side of the conveying mechanism (31), and a detection field of the posture sensor (52) faces a position where the hind limbs of the rat are located.

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