CN108379038B - A lower limb rehabilitation exoskeleton system and its walking control method - Google Patents

Abstract

The present invention relates to a kind of lower limb rehabilitation exoskeleton system and its walking control methods, belong to medical robot technical field.Walking control method includes Real time data acquisition step, gait phase identification step and ectoskeleton rate-determining steps；Ectoskeleton rate-determining steps include leading leg liftoff into the swing process that will be landed of leading leg in ectoskeleton, control its main supporting leg and keep generally upstanding state；And ectoskeleton be in lead leg liftoff gait phase when, and meet center of gravity transfer criterion after, control leading leg for ectoskeleton and carry out liftoff wobbling action；Center of gravity transfer criterion is that the upper body inclination angle of ectoskeleton wearer is in the first pre-set interval, and its plantar pressure is in the second pre-set interval.Based on the walking control method, lateral tilting moment can be effectively eliminated, so that it is guaranteed that the walking of ectoskeleton wearer is stablized, can be widely applied to weakness of the lower extremities or the rehabilitation training of hemiplegic patient.

Description

A lower limb rehabilitation exoskeleton system and its walking control method

technical field

The invention relates to a medical robot and a control method thereof, in particular to a lower limb rehabilitation exoskeleton system and a walking control method thereof.

Background technique

At present, my country has gradually entered an aging society, and the elderly population is becoming larger and larger. The main disease faced by a considerable part of the elderly population is stroke; in addition, various accidents are also increasing, resulting in a large number of patients with limb dysfunction. According to incomplete statistics, the number of the above-mentioned patients has exceeded 8 million. Among this huge group of patients, a considerable number of patients can improve or restore their motor function through rehabilitation training.

Commonly used rehabilitation training is mainly completed under the guidance of professional doctors and with the help of nurses or family members. This training method is not only time-consuming and labor-intensive, but also the effect of rehabilitation depends on the experience of doctors, nurses and family members. Its recovery effect is difficult to guarantee.

With the development of robotics, more and more scientific research institutions have begun to apply robotics to rehabilitation training to replace the existing rehabilitation training techniques that are expensive and difficult to guarantee. In the alternative, the exoskeleton rehabilitation robot is mainly used to assist patients in rehabilitation training, which can not only save labor costs, but also collect data during the rehabilitation process to formulate a better rehabilitation training plan.

The common walking control methods of exoskeletons for lower limb rehabilitation are: (1) Collect the gait information of normal people walking, and the gait information mainly includes the angles of hip, knee and ankle joints; (2) Control the exoskeleton to drive the patient Follow the gait curve of a normal person to walk in order to achieve rehabilitation. However, in order to maintain the balance effect of walking training, in situ rehabilitation training of suspended exoskeleton is usually used, which is difficult to simulate the real scene, which is not conducive to stimulating the rehabilitation interest and enthusiasm of the rehabilitation patients, or the rehabilitation patients use crutches in both hands to maintain balance, which is not conducive to It is suitable for patients with insufficient upper body arm strength or hemiplegia, so that this control method needs to face a big problem in practical application, that is, the lower limb muscles of patients with hemiplegia and lower limb weakness are weak, and it is difficult to support them to balance the swing phase of normal gait. The lateral overturning moment that occurs in the exoskeleton can easily lead to instability and even falls when the exoskeleton drives the patient to recover and walk.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a walking control method of the lower limb rehabilitation exoskeleton system to improve the stability of the walking process;

Another object of the present invention is to provide an exoskeleton system to improve its stability during walking.

In order to achieve the above-mentioned main purpose, the walking control method provided by the present invention includes a real-time data acquisition step, a gait phase identification step and an exoskeleton control step; , and lower extremity joint angle data; the gait phase identification step includes identifying the current gait phase of the exoskeleton wearer based on the lower extremity joint angle reference data and the lower extremity joint angle data acquired in real time; the exoskeleton control step includes swinging the legs of the exoskeleton During the swinging process from lifting off the ground to when the swinging leg will land on the ground, control its main support leg to maintain a roughly upright state; and when the exoskeleton is in the gait phase where the swinging leg is about to leave the ground, and after satisfying the center of gravity transfer criterion, control the exoskeleton’s movement. The swinging leg performs a swinging action off the ground; the center of gravity shift criterion is that the inclination angle of the exoskeleton wearer's upper body is within the first preset interval, and the sole pressure of the exoskeleton wearer is within the second preset interval.

After recognizing the gait phase of the exoskeleton wearer, during the swinging process of the swinging leg from when the swinging leg will leave the ground to when the swinging leg will land on the ground, the main support leg is controlled to maintain a roughly upright state; and before the swinging leg leaves the ground, the The inclination angle of the upper body and the pressure on the sole of the foot are kept within a predetermined range, so that the upper body of the wearer is inclined to the side of the main supporting leg until its center of gravity is transferred to the supporting surface of the main supporting foot, which effectively eliminates the lateral overturning moment, and the main supporting leg is approximately Keeping upright, most of the weight of the human body can be transferred to the ground through the exoskeleton support leg bar, reducing the burden on the wearer's support leg, thereby ensuring the exoskeleton wearer's walking stability, so that patients with weak lower limbs can also participate in the corresponding rehabilitation training.

The specific scheme is that the exoskeleton control step includes that when the exoskeleton is in the gait phase where the swing leg will land on the ground, and after the advance landing criterion is met, controlling the joint movements of the swing leg of the exoskeleton to the ground compliantly, and the advance landing criterion is the exoskeleton The plantar pressure of the skeletal wearer is within the third preset interval, and the compliant ground means that the plantar pressure of the swing leg during the landing process is less than the first preset value. When the swing leg touches the ground ahead of time, the movement rate of each joint is controlled to control the plantar pressure of the swing leg during the landing process to be below a predetermined value, so that the problem of hard landing can be effectively avoided if the swing leg is on the ground.

A more specific solution is that the control step includes voice prompting the exoskeleton wearer to adjust the upper body inclination if the exoskeleton is in the gait phase where the swinging leg will leave the ground and the center of gravity transfer criterion is not satisfied. That is, the exoskeleton wearer is reminded to adjust the inclination of the upper body by voice, which effectively avoids the lateral overturning moment caused by the center of gravity falling outside the support surface of the main support leg, and effectively improves the stability of the exoskeleton wearer during walking. .

A preferred solution is that the step of obtaining the preset interval and lower limb joint angle reference data includes a data collection step, a data processing step and a data coordination step; the data collection step includes collecting the walking gait of the sample population in the process of simulating the preset center of gravity transfer gait. Data, walking gait data includes lower limb joint angle data, upper body inclination data and sole pressure data; the preset center of gravity shift gait is based on the change of plantar pressure in the support phase and swing phase of a gait cycle, and the gait cycle Divided into eight gait phases, in the aforementioned eight gait phases, and in the gait phase included in the process from when the swinging leg will lift off the ground to when the swinging leg will land on the ground, the main support leg remains roughly upright; data processing steps Including filtering, amplifying, denoising and discretizing the walking gait data, obtaining the gait data of independent samples at different times in a cycle, and collecting the gait data of the sample population to form a gait database; the data coordinating step includes coordinating the gait data The gait data in the state database is used to obtain the preset range of the plantar pressure value and the preset range of the upper body inclination value corresponding to the lower limb joint angle values at different times in a gait cycle. The lower limb joint angle data at different times in a gait cycle constitute the lower limbs. Joint angle reference data.

A more preferred solution is that the real-time data acquisition step includes acquiring human-computer interaction force data, and the human-computer interaction force data is output by a tension sensor built into the upper and lower leg straps; the exoskeleton control step includes the process of controlling the movement of the lower limb joints of the exoskeleton. , keep the human-computer interaction force less than the second preset value. In order to enable the exoskeleton wearer to perform interactive force compliance control during walking.

In order to achieve the above-mentioned other object, the lower limb rehabilitation exoskeleton system provided by the present invention includes a control unit, a detection unit that inputs a detection signal to the control unit, and an exoskeleton controlled by the control unit; the detection unit includes a plantar pressure detector, an upper body inclination detection The control unit includes a processor and a memory, and the memory stores a computer program. When the computer program is executed by the processor, the real-time data acquisition step, the gait phase recognition step and the exoskeleton control step can be realized; the real-time data The acquiring step includes acquiring, in real time, the plantar pressure data output by the plantar pressure detector, the upper body inclination angle data output by the upper body inclination detector, and the lower limb joint angle data output by the lower limb joint angle detector; The reference data, based on the real-time acquired lower limb joint angle data, identify the current gait phase of the exoskeleton wearer; the exoskeleton control step includes controlling the main support of the exoskeleton during the swinging process from when the swinging leg of the exoskeleton will leave the ground to when the swinging leg will land on the ground. The legs are kept in a roughly upright state; and when the exoskeleton is in the gait phase where the swinging leg will lift off the ground, and the center of gravity transfer criterion is met, the swinging leg of the exoskeleton is controlled to swing off the ground; the center of gravity transfer criterion is for the exoskeleton wearer The inclination angle of the upper body is within the first preset interval, and the plantar pressure is within the second preset interval.

After recognizing the gait phase of the exoskeleton wearer, during the swinging process of the swinging leg from when the swinging leg will leave the ground to when the swinging leg will land on the ground, the main support leg is controlled to maintain a roughly upright state; and before the swinging leg leaves the ground, the The inclination angle of the upper body and the pressure on the sole of the foot are kept within a predetermined range, so that the upper body of the wearer is inclined to the side of the main supporting leg until its center of gravity is transferred to the supporting surface of the main supporting foot, which effectively eliminates the lateral overturning moment, and the main supporting leg is approximately Keeping upright, most of the weight of the human body can be transferred to the ground through the exoskeleton support leg bar, reducing the burden on the wearer's support leg, thereby ensuring the exoskeleton wearer's walking stability, so that patients with weak lower limbs can also participate in the corresponding rehabilitation training.

The specific scheme is that the exoskeleton control step includes that when the exoskeleton is in the gait phase where the swing leg will land on the ground, and after the advance landing criterion is met, controlling the joint movements of the swing leg of the exoskeleton to the ground compliantly, and the advance landing criterion is the exoskeleton The plantar pressure of the skeletal wearer is within the third preset interval, and the compliant ground means that the plantar pressure of the swing leg during the landing process is less than the first preset value. When the swing leg touches the ground ahead of time, the movement rate of each joint is controlled to control the plantar pressure of the swing leg during the landing process to be below a predetermined value, so that the problem of hard landing can be effectively avoided if the swing leg is on the ground.

A more specific solution is that the control step includes voice prompting the exoskeleton wearer to adjust the upper body inclination if the exoskeleton is in the gait phase where the swinging leg will leave the ground and the center of gravity transfer criterion is not satisfied. That is, the exoskeleton wearer is reminded to adjust the inclination of the upper body by voice, which effectively avoids the lateral overturning moment caused by the center of gravity falling outside the support surface of the main support leg, and effectively improves the stability of the exoskeleton wearer during walking. .

A preferred solution is that the step of obtaining the preset interval and lower limb joint angle reference data includes a data collection step, a data processing step and a data coordination step; the data collection step includes collecting the walking gait of the sample population in the process of simulating the preset center of gravity transfer gait. Data, walking gait data includes lower limb joint angle data, upper body inclination data and sole pressure data; the preset center of gravity shift gait is based on the change of plantar pressure in the support phase and swing phase of a gait cycle, and the gait cycle Divided into eight gait phases, in the aforementioned eight gait phases, and in the gait phase included in the process from when the swinging leg will lift off the ground to when the swinging leg will land on the ground, the main support leg remains roughly upright; data processing steps Including filtering, amplifying, denoising and discretizing the walking gait data, obtaining the gait data of independent samples at different times in a cycle, and collecting the gait data of the sample population to form a gait database; the data coordinating step includes coordinating the gait data The gait data in the state database is used to obtain the preset range of the plantar pressure value and the preset range of the upper body inclination value corresponding to the lower limb joint angle values at different times in a gait cycle. The lower limb joint angle data at different times in a gait cycle constitute the lower limbs. Joint angle reference data.

A more preferred solution is that the real-time data acquisition step includes acquiring human-computer interaction force data, and the human-computer interaction force data is output by a tension sensor built into the upper and lower leg straps; the exoskeleton control step includes the process of controlling the movement of the lower limb joints of the exoskeleton. , keep the human-computer interaction force less than the second preset value. In order to enable the exoskeleton wearer to perform interactive force compliance control during walking.

Description of drawings

1 is a schematic structural diagram of an embodiment of an exoskeleton system of the present invention worn on an exoskeleton wearer;

FIG. 2 is a schematic diagram of the arrangement position of the plantar pressure sensor in the embodiment of the exoskeleton system of the present invention;

FIG. 3 is a schematic diagram of the electrical control structure of an embodiment of the exoskeleton system of the present invention.

FIG. 4 is a schematic diagram of the process of the preset center of gravity shifting gait in an embodiment of the exoskeleton system of the present invention;

5 is a flow chart of constructing a gait database for center of gravity transfer in an embodiment of the exoskeleton system of the present invention;

FIG. 6 is a flowchart of a walking control method according to an embodiment of the exoskeleton system of the present invention.

Detailed ways

The present invention will be further described below with reference to the embodiments and the accompanying drawings.

Example of an exoskeleton system

1 to 3 , the exoskeleton system 1 of the present invention includes a control unit, a detection unit that inputs a detection signal to the control unit, and an exoskeleton controlled by the control unit.

As shown in FIG. 1 , the exoskeleton system includes a control backpack 10 worn on the exoskeleton wearer. The control backpack 10 includes a backpack strap 100 , a backpack bag 101 , a power supply battery 103 and a main control unit 102 placed in the backpack bag 101 . , the main control unit 102 constitutes the control unit in this embodiment, the main control unit 102 includes a processor and a memory, and the power supply battery 103 supplies power for the normal operation of the entire exoskeleton system.

As shown in FIGS. 1 and 2 , the exoskeleton unit includes a waist wearing unit 11 , a hip joint unit 12 , a thigh rod 14 , a thigh strap 13 , a knee joint unit 15 , a calf strap 16 , a calf rod 17 , and an ankle joint unit 18 And the flexible sole unit 19. The waist wearing unit 11 is used for fixing the exoskeleton and the waist of the human body; the hip joint unit 12, the knee joint unit 15 and the ankle joint unit 18 all include a joint driver, the joint driver joint motor and the matching reducer are used to drive the exoskeleton correspondingly The upper hip joint, knee joint and ankle joint rotate; the thigh rod 14 is used to drive the human thigh to move, and the calf rod 17 is used to drive the human calf to move. The strap is used to connect the leg bar and the leg to fix the exoskeleton; wherein, two leg thigh straps 13 are tied on each thigh; the flexible sole unit is worn with the human foot.

The detection unit includes an upper body inclination detector for detecting the inclination of the upper body of the exoskeleton wearer, and a lower limb joint angle detector for detecting the joint angle of the lower limbs, which is installed on the flexible sole unit 19 for detecting different positions of the sole of the exoskeleton wearer. The plantar pressure detector for the pressure at the place, and the sensor for measuring the human-machine interaction force between the human and the exoskeleton; these detectors output real-time detection signals to the main control unit 102, including the upper body inclination signal, the lower limb joint angle signal, the foot Bottom pressure signal and human-computer interaction force signal. In this embodiment, the upper body inclination detector is an upper body inclination sensor arranged in the control backpack 10. In this embodiment, the upper body inclination sensor selects a gyroscope, which is used to measure the position of the exoskeleton wearer's upper body in the sagittal plane of the human body. The inclination data on the frontal plane; the lower limb joint angle detector is a joint angle sensor placed at the corresponding joint, which is used to measure the rotation angles of the hip joint, knee joint and ankle joint on the exoskeleton, a total of 6; human-computer interaction force The force sensor is an S-type tension pressure sensor, which is used to measure the human-computer interaction force between the human and the exoskeleton, that is, it is used to detect the change of the interaction force between the thigh rod and the thigh or the calf rod and the calf. There are 6 in the calf straps in total; the plantar pressure detector is a plantar pressure sensor placed on the flexible sole unit, specifically the FlexiForce type pressure sensor from Tekscan Company in the United States, which is used to measure the pressure at different positions on the left and right soles , as shown in Figure 2, the specific detection positions are 4 positions of the heel, the forefoot, and the toe, that is, there are 4 positions on each sole, 8 in total.

As shown in FIG. 3 , the detection signals collected by the detection sensors in the detection unit 30 are sent to the main control unit 102 through the acquisition card 31 , and the main control unit 102 controls the driver 32 to drive each joint motor 33 to act according to the detection signals and a predetermined program. , the joint motor drives the corresponding joint movement of the exoskeleton, thereby assisting the exoskeleton wearer to complete the predetermined rehabilitation training action. The following real-time processing is performed on the signals collected by the acquisition card 31:

(1) Filter processing: band-pass filtering the signal;

(2) Enlargement processing;

(3) Noise removal processing. The removed noise includes the DC component in the detection signal, the high-frequency noise of skin friction and the power frequency interference. Specifically, the weighted average method is used to increase the signal-to-noise ratio, thereby reducing the impact of noise on the detection signal. ;

(4) Data discretization processing.

Before using the above-mentioned exoskeleton system, it is necessary to build a center-of-gravity transfer gait database. In this embodiment, the process of building the center-of-gravity transfer gait database includes letting the sample population walk in a pre-designed preset center-of-gravity transfer gait. After the sample population is proficient in the preset center of gravity shifting gait, the gait information data of the sample population in the process of simulating the preset center of gravity shifting gait is collected through the three-dimensional optical motion capture system, upper body inclination sensor, and foot pressure sensor. The collected data builds the center of gravity shift gait database. As shown in Figure 5, the construction process of the center of gravity shift gait database includes the following steps:

(1) In the training step S11 , the normal sample population is allowed to walk in a simulated preset center of gravity shift gait and master it proficiently.

In this embodiment, the preset center of gravity shift gait is shown in FIG. 4 . In this figure, the right foot is represented by a solid line and the left foot is represented by a dotted line. According to the support phase and the swing phase of a gait cycle, the right foot is represented The change of bottom pressure divides a gait cycle into 8 stages, and the 8 stages have 8 phases, namely (A) full foot support - front, the whole bottom of the right foot is on the ground, and the right foot is in front, at this time , the body weight is evenly divided on the left and right feet; (B) full foot support - turn, the right leg is roughly upright, the bottom of the right foot is on the ground, and the left sole touches the ground lightly. Transfer to the right foot support surface, most of the body weight is supported on the right leg; (C) full foot support—support, the right leg is roughly upright, the bottom of the right foot is on the ground, and the left foot swings off the ground. The upper body of the human body is tilted to the right, the center of gravity is still on the support surface of the right foot, and the body weight is completely supported by the right foot; (D) full-foot support-spread, the right leg is roughly upright, the bottom of the right foot touches the ground, and the left heel touches the ground lightly. The upper body of the human body is tilted to the right, and most of the body weight is supported by the right foot; (E) Full foot support - back, the bottom of the right foot is on the ground, and the right foot is behind, at this time, the body weight is equally distributed on the left and right feet; (F ) The sole of the foot is on the ground, the left leg is roughly upright, the bottom of the left foot is on the ground, and the sole of the right foot touches the ground lightly. At this time, the upper body of the human body is tilted to the left, and the center of gravity is transferred from both feet to the supporting surface of the left foot. Most of the weight is supported on the ground. On the left leg; (G) The sole of the foot is off the ground, the left leg is roughly upright, the bottom of the left foot is on the ground, and the right foot swings off the ground. Support; and (H) the heel is on the ground, the left leg is roughly upright, the bottom of the left foot is on the ground, and the right heel touches the ground lightly. Let the sample population repeat the above preset center of gravity transfer gait in turn to mastery.

That is, in the preset center of gravity transfer gait, in the support phase, the right leg is the main support leg, and the left leg is the swing leg; in the swing phase, the right leg is the swing leg, and the left leg is the main support leg; And in the process from (B) full foot support-turning phase to (D) full foot support-spreading phase and (F) foot support grounding phase to (H) heel grounding phase, the swing leg of the exoskeleton will lift off the ground to this point. The swinging process where the swinging leg will hit the ground.

(2) Data collection step S12, collecting the walking gait information data of the sample population who have mastered the aforementioned preset center-of-gravity shifting gait during the process of simulating the preset center-of-gravity shifting gait.

Through the three-dimensional optical motion capture system opttrack, the upper body inclination sensor, and the plantar pressure sensor, the walking gait data of the sample population in multiple cycles of simulating the preset center-of-gravity shifting gait walking process are obtained. The walking gait data includes the lower limb joint angle data, Plantar pressure data and upper body posture data; among them, the lower limb joint angle data includes the joint angle data of the hip joint, knee joint and ankle joint, the plantar pressure data includes the pressure data of the heel, forefoot and toe, and the upper body posture data includes the human body The inclination data of the upper body in the sagittal and frontal planes of the human body. Among them, the plantar pressure data is detected and collected by plantar pressure sensors arranged at different positions on the sole of the foot. The plantar pressure pressure sensor is selected from the FlexiForce pressure sensor of Tekscan Company in the United States. The arrangement of the four pressure sensors is shown in Figure 2. It is located in 4 positions of the heel, forefoot and toe, which are used to detect the contact state of the sole of the foot and the ground and its interaction force.

(3) Constructing a database step S13, processing the collected walking gait data to construct a center-of-gravity transfer gait database.

(3.1) Data processing step: filter, amplify, de-noise and discretize the collected gait data of multiple cycles to obtain gait data at any time in a cycle. The gait data includes joint angle data, foot Bottom pressure data and upper body inclination data;

(3.2) Steps of building a database: Repeatedly collecting multiple groups of data from the sample population above the preset number threshold and performing data processing to establish a database. (1) Compare the differences between different periods of the same sample and the differences between different samples, integrate the data and optimize, specifically remove the data with large differences, in this embodiment, remove the ratio that deviates from the overall average value exceeding the predetermined Set the threshold data, such as more than 30%, and average the remaining data to obtain the sample data in the database; (2) coordinate all the sample data, and obtain the joint angle value at any time in a gait cycle. The plantar pressure value at the corresponding moment The confidence interval and the confidence interval of the upper body inclination value, and the position of the center of gravity at any time in the gait cycle can be obtained according to the change of the plantar pressure. The value is used as the endpoint value of the confidence interval of this type of data for the sample population within the preset weight interval; then it is divided according to the 8 phases of the gait, and the (B) full foot support-the data confidence interval of the phase transition is used as the control exoskeleton. The criterion for the timing of the driver's hind leg off the ground is defined as the center of gravity transfer criterion, that is, the phase when the hind foot will leave the ground, by judging whether the plantar pressure is within the confidence period of the plantar pressure and whether the upper body inclination is within the confidence period of the upper body inclination. To judge whether the center of gravity has shifted or not; take (D) full foot support - the data confidence interval of the split phase as the criterion for controlling the timing of the exoskeleton driving the front foot landing, which is defined as the advance landing criterion, that is, when the front foot will touch the ground, the Determine whether there is an early landing during the landing process. For each phase, it is judged that the upper body inclination and the plantar pressure are within the confidence interval, which is used as the stability criterion for the exoskeleton to walk stably. The confidence interval of the plantar pressure value constitutes the second preset interval and the third preset interval in this embodiment, and the confidence interval of the upper body inclination value constitutes the first preset interval in this embodiment.

Referring to FIG. 6 , according to the above-mentioned built-up gravity center transfer walking database, the control method for controlling the above-mentioned exoskeleton system to walk includes the following steps:

(1) The parameter initialization step S21 is to initialize the control parameters of the exoskeleton system according to the physical information of the recovered patient, so as to select the confidence interval corresponding to the body weight, that is, the preset interval.

After the rehabilitated patient puts on the exoskeleton system 1 and is ready, the exoskeleton system first drives the patient's lower limbs to shake slightly for a period of time, and takes the average value of the sum of the measured plantar pressure values as the reference weight value, and according to the obtained weight value, select the sub-database corresponding to the preset weight range where the weight value is located, and the corresponding sub-database includes the lower limb joint angle and its corresponding upper body inclination angle confidence interval and plantar pressure confidence interval, and the measured human-computer interaction force is used as a reference The initial value of the machine interaction force.

(2) Real-time data acquisition step S22, acquiring the walking gait data of the detection unit for the patient wearing the exoskeleton system during the rehabilitation training process.

When a patient and other rehabilitation personnel wear the exoskeleton system 1 for walking rehabilitation training, the detector 30 collects their walking gait information during the rehabilitation training process. Specifically, the inclination data of the upper body of the rehabilitation patient on the sagittal plane and frontal plane of the human body is measured in real time by the upper body inclination sensor, and the angle data of the exoskeleton joints, that is, the rotation angle data of the hip joint, knee joint and ankle joint measured in real time by the angle sensor. , measure the pressure data of the left and right soles in real time through the plantar pressure sensor, and measure the human-computer interaction force between the human and the exoskeleton through the human-computer interaction force sensor.

(3) Data processing step S23 , performing filtering, signal amplification, denoising and discretization processing on the received walking gait data.

(4) gait stability judgment step S24, according to the collected walking gait data, according to the stability criterion to judge whether the walking state of the exoskeleton is stable; Control the joint angle of the exoskeleton as quickly as possible to reach a stable state; if stable, perform real-time recognition of the gait phase.

(5) Step S25 of gait phase identification, compare the joint angle data in the walking gait data collected in real time with the joint angle data in the gait database, and identify the real-time gait phase of the exoskeleton, that is, determine the current Which of the eight phases the moment is in.

(6) Exoskeleton control step S26, according to the current lower limb joint angle data, upper body inclination data and sole pressure data, the joint angle data at the next moment is matched; and when the swinging leg is about to leave the ground, it is judged whether the center of gravity transfer judgment is satisfied According to the data, the timing of the swing leg leaving the ground is controlled; when the swing leg is about to touch the ground, it is judged whether the early landing criterion is satisfied, so as to control the joint action of the swing leg during the early landing process to achieve a smooth landing.

(6.1) When it is judged that the exoskeleton is in the phase where the swinging leg is about to leave the ground, namely (B) the full foot support-rotation phase and (F) the sole support phase, according to the center of gravity transfer criterion, compare the soles of the feet collected at this moment The pressure, upper body inclination data and the data corresponding to the database phase are used to judge whether the center of gravity has been transferred; if the patient's center of gravity has not been transferred or is not fully transferred, the back foot is stressed. Among the pressure on the sole of the rear foot, there are three pressures on the toe and the sole of the forefoot. The pressure value collected by the sensor will be relatively large, and the sum of the three pressure values exceeds the confidence value of the center of gravity transfer of the rear foot. Usually, the confidence value is 15% of the weight value obtained in the parameter initialization step, and the sum of the pressure values of the front foot will be low. The confidence value of the transfer of the center of gravity of the forefoot is usually taken as 85% of the weight value obtained in the parameter initialization step; at this time, the exoskeleton will voice through the speaker to prompt the wearer to slightly tilt the upper body, and further remind the side according to the upper body inclination data. On the other hand, if the patient's center of gravity has shifted to the right position, the back foot just touches the ground lightly, and the pressure values collected by the three pressure sensors on the toe and the forefoot will be compared in the sole pressure of the back foot. Small, the sum of the three pressure values is less than the confidence value of the center of gravity transfer of the rear foot. Usually, the confidence value is 15% of the weight value obtained in the parameter initialization step. At the same time, the sum of the pressure values of the forefoot soles will be greater than the confidence value of the center of gravity transfer of the forefoot. Usually Take this confidence value as 85% of the weight value obtained in the parameter initialization step.

(6.2) When it is judged that the exoskeleton is in the phase where the swinging leg is about to hit the ground, namely (D) full foot support-spread phase and (H) heel support phase, compare the plantar pressure collected at this moment according to the advance landing criterion , The upper body inclination data and the data corresponding to the database phase, to determine whether the exoskeleton will land in advance. For example, when there is a bump on the travel path, the swing leg of the exoskeleton will land earlier than the preset time, that is, the corresponding joint of the swing leg The angle data does not reach the landing data, and the plantar pressure data appears in advance on the sole of the swing leg. At this time, the pressure value at the heel in the sole pressure of the swing leg will increase in advance. At this time, according to the value of the plantar pressure and the joint angle, the exoskeleton joint angle curve is timely and reasonably corrected, so that the exoskeleton can land compliantly and avoid the impact and instability caused by the early landing of the exoskeleton swing leg.

(6.3) Transfer the matched lower extremity exoskeleton joint angle information to the corresponding joint motor driver to control the rotation of the corresponding joint motor. During the motor rotation process, the real-time measurement is obtained by the S-shaped tension sensor built in the upper and lower leg straps. The human-computer interaction force between the human and the exoskeleton can realize the compliant control of the human-computer interaction force. If the measured human-computer interaction force exceeds the set maximum value, reduce the motor speed and reduce the motor output shaft torque to ensure the human-computer interaction force. The human-computer interaction force with the exoskeleton is within a safe and comfortable range, ensuring good human-machine coordination between the human and the exoskeleton, so as to realize the stable control of the exoskeleton.

In the main control unit 102 of the exoskeleton system, a computer program is stored in its memory. When the computer program is executed by the processor, the above-mentioned parameter initialization step S21, real-time data acquisition step S22, data processing step S23, and step S23 can be realized. State stability determination step S24, gait phase identification step S25, and exoskeleton control step S26.

Example of walking control method

The embodiments of the walking control method of the present invention have been described in the above-mentioned embodiments of the exoskeleton system, and are not repeated here.

Claims (5)

1. a kind of lower limb rehabilitation exoskeleton system inputs the detection list of detection signal including control unit, to described control unit Member and the ectoskeleton controlled by described control unit；

It is characterized in that, the detection unit includes plantar pressure detector, upper body tilt angle detector and the inspection of joint of lower extremity angle Device is surveyed, described control unit includes processor and memory, and the memory is stored with computer program, the computer program Following steps are able to achieve when being executed by the processor:

Real time data acquisition step obtains the plantar pressure data of the plantar pressure detector output in real time, the upper body inclines The upper body inclination data of angle detector output and the joint of lower extremity angle-data of joint of lower extremity angle detector output；

Gait phase identification step, according to joint of lower extremity angle reference data, based on the joint of lower extremity angle-data obtained in real time, Identify the current gait phase of ectoskeleton wearer；

Ectoskeleton rate-determining steps are controlled in leading leg in the swing process led leg and will landed for ectoskeleton Its main supporting leg keeps generally upstanding state；And when ectoskeleton is in and leads leg liftoff gait phase, and meeting weight After the heart shifts criterion, controls leading leg for ectoskeleton and carry out liftoff wobbling action；The center of gravity transfer criterion is ectoskeleton wearing The upper body inclination angle of person is in the first pre-set interval, and its plantar pressure is in the second pre-set interval；Pendulum is in ectoskeleton When the gait phase that dynamic leg will land, and after meeting the criterion that lands in advance, the joint action of ectoskeleton led leg is controlled extremely Its is submissive to land, and the plantar pressure that criterion is ectoskeleton wearer that lands in advance is in third pre-set interval, described soft It is the plantar pressure led leg in the process of landing less than the first preset value along ground.

2. exoskeleton system according to claim 1, which is characterized in that the ectoskeleton rate-determining steps include:

If ectoskeleton is in when leading leg liftoff gait phase, and is unsatisfactory for the center of gravity transfer criterion, then voice reminder Ectoskeleton wearer adjusts upper body inclination angle.

3. exoskeleton system according to claim 1 or 2, which is characterized in that obtain pre-set interval and joint of lower extremity angle The step of reference data includes:

Data collection steps, walking step state data of collecting sample crowd during simulating default center of gravity transfer gait are described Walking step state data include joint of lower extremity angle-data, upper body inclination data and foot force data；The default center of gravity transfer Gait is the situation of change according to plantar pressure in the support phase and swing phase of a gait cycle, and the gait cycle is divided For eight gait phases, in eight gait phases, and leading leg the liftoff process institute that leads leg and will land to this On the gait phase for including, main supporting leg keeps generally upstanding；

Data processing step, is filtered the walking step state data, amplifies, denoising and sliding-model control, obtains independent sample The gait data of this different moments within a period, the gait data for gathering the sample population constitute gait data library；

Data plan as a whole step, plan as a whole gait data in the gait data library, obtain in a gait cycle under different moments The corresponding plantar pressure value pre-set interval of limb joint angle angle value and upper body inclination value pre-set interval, when different in a gait cycle The joint of lower extremity angle-data at quarter constitutes joint of lower extremity angle reference data.

4. exoskeleton system according to claim 3, it is characterised in that:

The Real time data acquisition step includes obtaining human-computer interaction force data, and the human-computer interaction force data is by being built in size Tension sensor output in leg bandage；

The ectoskeleton rate-determining steps include keeping human-computer interaction power small during controlling the joint of lower extremity movement of ectoskeleton In the second preset value.

5. exoskeleton system according to claim 1 or 2, it is characterised in that:

The Real time data acquisition step includes obtaining human-computer interaction force data, and the human-computer interaction force data is by being built in size Tension sensor output in leg bandage；

The ectoskeleton rate-determining steps include keeping human-computer interaction power small during controlling the joint of lower extremity movement of ectoskeleton In the second preset value.