Student Projects
Contact Information
Year Submitted: 2017
University: LUNGHWA UNIVERSITY OF SCIENCE AND TECHNOLOGY
List of Team Members (with year of graduation):
PAN, GUAN-YU (2017)
JIAN, RUEI-HONG (2018)
LIN, JING-HUA (2019)
LIN, LI-SING (2019)
WU, ZONG-HAN (2019)
Faculty Advisers: LI, LIAN-WANG
Main Contact Email Address: leelw@mail.lhu.edu.tw
Submission Language: English/Traditional Chinese
Project Information
Title: By using to myRIO for Smart mobile multi-functional gait training system
Description:
Creation in the analysis and reference to the results at home and abroad, based on the system to achieve the function and rehabilitation training needs, planning intelligent mobile multi-functional gait training system overall design
Products:
Software:
LabVIEW
LabVIEW Real-Time Module
LabVIEW FPGA Module
Hardware:
NI myRIO1900 ×2
Others:
Maxon EC Flat motor ×4
ELCO Encoder ×4
Tension Sensors ×2
Linear Actuators ×2
HOKUYO Radar range finder ×1
Faulhaber DC moter ×2
IP CAM ×1
HC SR04 ×3
The Challenge:
Using a composite structure design,so that rehabilitation can also be outdoors, in addition to gait training to meet the needs of walking dysfunction and gait training, but also for the elderly frail and lower limb weakened to provide walking assistance to achieve lower limb gait training and action-assisted multi-in-one ultra-lightweight intelligent design.
The Solution:
Ⅰ. the system architecture
Creation in the analysis and reference to the results at home and abroad, based on the system to achieve the function and rehabilitation training needs, planning intelligent mobile multi-functional gait training system overall design, figure 1 is the overall structure of the system, the overall mechanical structure of the system include: external frame, mobile suspension weightloss support system (shown in figure 2), mobile aids (shown in figure 3) and wearable lower extremity exoskeleton system (shown in figure 4). The control system consists of an embedded controller, a rotary encoder, a tension sensor, an ultrasonic sensor and a laser range finder: The United States National Instrument Co. Ltd. (NI) production of embedded control system myRIO as the host control core, In the LabVIEW control software environment editing program and into the gait trajectory parameters in the FPGA mode, real-time processing of digital signals, The fastest and accurate speed of the system I / O signal interception, conversion and decoding and control, and then realize the intelligent mobile multi-functional gait training system.
As the mobile suspension weight reduction support system, the size of its weight reduction is not only related to the output torque of the linear actuator, but also with the patient's gait frequency, step size and body weight and height. Therefore, the actual rehabilitation training, not only to consider the linear actuator input voltage, but also consider the patient's own factors. In order to provide accurate suspension weightloss, The creation will be done by NI myRIO accurate input and output control voltage to brake in the vertical installation of two sets of linear actuators and tension sensors, Respectively, the design of suspension weightloss support system force and location of the double closed loop controller, In patients with gait training, for different weight of patients or users, under different weightloss conditions, the walking suspension weight support system closed loop control.
In the action auxiliary part, with the motion control and auxiliary navigation function. Through myRIO grab the laser range finder to detect the environmental parameters, to be calculated and control, in order to achieve the function of navigation obstacle avoidance, or use the direction control button to perform manual operation, and thus control the speed and direction of the DC motor, The motion control is driven by the DC motor to control the movement of the mobile assist system.
Figure 1: overall structure of the system
Figure 2: Mobile suspension weightloss support system
Figure 3: mobile aids
Figure 4: wearable lower extremity exoskeleton system
Ⅱ. the mechanism design
ⅰ. Wearable lower extremity exoskeleton system
Wearable lower extremity exoskeleton help leg design is an important part of the gait training system, the design of the wearable lower extremity exoskeleton is an important part of the gait training system. The gait characteristics of the patient and the characteristics of the lower limb movement of the human body must be taken into account. In particular, the system is in direct contact with the human body and is based on ergonomics. Security and comfort and other factors, so the design of the system will affect the implementation of the entire system functions and the implementation of the program results. Normal leg of the hip joint flexion and extension, external rotation and outreach adduction three degrees of freedom; knee flexion and extension movement of the moment trajectory is a curve, it can be approximated as a degree of freedom; ankle flexion and extension and the abduction received two degrees of freedom. Considering the complexity of the leg movement, the design of the main consideration of hip abduction and adduction and three joints of the rotation. Wearable exoskeleton help leg design needs to face the needs of the majority of patients, so not only to consider the patient's body height, fat and thin, but also to the size of the various organs of the robot according to different patient status, in the length and width can have Adjustable, so that patients can feel comfortable in training. For normal people, everyone's own parts, the length between the part and the part, ratio and size are basically the same. Because the different legs of the various sizes are not the same, so the design to be able to meet the compatibility, so that the size of the important parts of the body leg to be adjusted as far as possible, the body design in the thigh and calf Length, hip width, body level can be adjusted, so that can meet the different height and weight of the user. The photograph is shown in figure 5.
Figure 5: wearable exoskeleton legs entity booster photo
ⅱ. mobile suspension weight reduction support system
Due to the patient's physical defects, the patient's legs have been unable to fully bear their own weight. According to the theory of rehabilitation medicine, only try to imitate the normal walking gait in order to achieve the best rehabilitation effect. Therefore, in the gait training must have a weightloss system to reduce the force of the patient's legs, so that training to achieve better results. The main purpose of the institution is in order to reduce the patient's leg strength, so that patients can more freedom of movement. Mobile suspension weightloss support system in the design of the external framework as the basis, to coordinate with each other. Because the patient is physically defective, the legs of the walking function has a certain obstacle, and legs can’t fully bear the weight of their entire body. Therefore, based on the knowledge of rehabilitation medicine, so that patients in training as much as possible to imitate the normal walking gait for the rehabilitation effect is the best. Therefore, in patients with leg gait training, the patient's legs must be reduced to bear their own weight, in order to make the patient's training results to achieve the best, suspension weightloss support system design is very necessary. Design suspension weightloss mechanism is designed to reduce the patient's leg tolerance, so that patients in the training when the legs can be more comfortable movement. The design of the mobile suspension weightloss support system, is through myRIO output control voltage and driven by a linear actuator, active suspension to complete the weightloss, the two linear actuator symmetrical on the left and right, so that the force evenly balanced. Mobile suspension weightloss support system as shown in figure 6, in the training process, according to the patient's lower limb rehabilitation of the specific situation, through the embedded system to set the appropriate weightloss, the linear actuator and then drive mobile suspension weight support system will be the appropriate lifting or down the body to achieve the purpose of weightloss.
Figure 6: mobile suspension weight reduction support system body diagram
ⅲ. mobile aids
In recent years, due to the robot technology, sensing technology, biotechnology, intelligent control technology and the rapid development of computer technology for the development of mobile aids to bring a fast opportunity. The design of the auxiliary navigation system is an important part of the action aids, mainly used to solve the action of auxiliary devices in the local area of the navigation problem. The use of action aids is also indispensable for safety and reliability. From the security considerations, System in addition to human control obstacle avoidance, also to take the initiative to avoid obstacles and security alerts. The information of the distance between the mobile assistive system and the surrounding obstacle is obtained by the ultrasonic sensor and the laser range finder to provide support for how to avoid the decision of the obstacle. The creation used myRIO to intercept the sensor signal, analyze the surrounding environment and based on the wireless communication system, design and implementation of mobile assistance system remote monitoring. Action of the auxiliary system can be divided into movement and navigation two parts, the movement part of the user is responsible for perception and accurate and reliable robot motion control. The system can be artificially controlled obstacle avoidance can also take the initiative to avoid obstacles and security alerts. The motion control will consist of a DC motor, an acceleration sensor and a directional control button, through the speed sensor to calculate the current moving aids moving speed, through the direction control button to obtain the user's walking intention, analysis of intent and calculation speed to control the speed of the DC motor, the mobile auxiliary system entity diagram as shown in Figure 7.
Figure 7: Mobile auxiliary entity diagram
Ⅲ. Drive control design
ⅰ. Wearable lower extremity exoskeleton
This wearable lower extremity exoskeleton to introduction of weightloss gait training, reduce the burden of rehabilitation physicians, reduce patient suffering, improve the rehabilitation effect, reducing rehabilitation time is one of the main goals of this creation. In the design of lower limb exoskeleton, the main consideration of the hip, knee and ankle sagittal within the training to help patients resume walking ability. Simultaneously, consider the safety of walking, to the joint maximum range of activities as the design of lower extremity exoskeleton safety work space reference. The traditional walking training system is through the weightloss mechanism and the lower extremity joint orthodontic coordination operation to treadmill driven to achieve reciprocating training. The weightloss mechanism of the traditional gait training system is to control the movement of the center of gravity in the vertical direction, the assisting mechanism is to control the swing angle of the hip and knee joint. If there is no forward movement of the body of gravity, the user can only achieve in situ gait training, but the reciprocating training only applies to the early hemiplegia lower limb muscle strength recovery, and can’t meet to a patient with walking ability but lower limb weakness the ability of the normal walking to demand. Therefore, the creative design can help the user to achieve the ground walking of lower extremity exoskeleton. The design of the lower limb exoskeleton by Figure 8 shows the flat motor, with Figure 9 shows the harmonic reducer drive hip and knee to achieve the lower extremity exoskeleton flexion and extension movement. Angle sensor installed in the lower extremity exoskeleton of the joints, used to detect the angular displacement of each joint, and the angle sensor output signal back to the embedded system, and then by the embedded system to drive the lower limb on the external bone flat motor, respectively, control the hip and knee movement, constitute a complete closed loop control system. An embedded system in which the device is mounted can record the gait parameters of the patient, instantly display the gait information and instantly control the exoskeleton of the lower limbs.
Figure 8：EC flat motor
Figure 9：Harmonic Drive
ⅱ. mobile aids
The design of the action by the use of laser range finder to detect the front of the body obstacles, the range finder provides a set of RS-232 and USB communication interface, the entity photo shown in Figure 10. The range of the laser range finder is the entire plane, without the need to place the mark in advance, and does not require a specific reflector to assist in scanning. The size of the light source does not affect the scanning range and accuracy. Laser range finder is to measure the time and time of the laser pulse to calculate the distance, the laser pulse hit the obstacles will be reflected and refraction back, the distance meter by the reflected light pulse signal can be transmitted and received time difference, that is, the pulse of the flight time, in the use of the speed of light and flight time to calculate the distance between the obstacles and distance finder and location. The laser range finder has a rotatable reflector inside, so the laser light pulse can be fired at different angles,the surrounding environment for fan-shaped area of the scan, the outline of the obstacles can be obtained by continuous pulse reception. In addition,for the central angle of the scan fan area can be self-defined, the scanning angle of up to 240 degrees, the resolution of up to 0.3515 degrees, the scanning data from USB or RS-232 to 19.2,57.6 or 115.2kbps transmission rate by sent back, As the touch panel supports a maximum transfer rate of 115.2kbps,so the action of the auxiliary to 115.2kbps transmission rate and touch the tablet to do the transmission of information. The laser range finder can scan for an angle of up to 240 degrees, providing a scanning distance of 0.36 degrees each time, and the power consumed is not high (2.5W), making it ideal for use as an environmental sensor for action aids. In the use, as installed in front of the mobile aids, so do not need to set the range of the laser rangefinder to 240 degrees, the creation set the scanning area of the scan area of the fan area of 120 degrees, and the maximum effective detection distance of the action aids to 2.5 meters. Figure 13 is an actual photograph of the mobile aids to propulsion motor. Action Auxiliary drive system design is according to 0.1m wheel diameter, to 3 km per hour of travel speed, and to 2 times the safety factor to calculate, DC motor with 23: 1 reducer, single-wheel maximum continuous output torque up to 1.3064N-m,the maximum continuous output speed of the motor with the gearbox is 226.52 rpm. The motor has the advantages of small size, light weight and large driving force, which can monitor the speed, position and current from the embedded system, and can limit the torque output and speed control, so it is suitable for driving the design of the mobile aids.
Figure 10：The Laser range finder
ⅲ. mobile suspension weightloss support system
To provide a constant weightloss of the training process, the creation of two groups of structures symmetrical linear actuator, to close the loop control mode for dynamic weightloss, according to the patient's different gait training needs, enter the desired weightloss ratio through the touch interface of the action aid, and then by the embedded system to control the linear actuator to achieve real-time dynamic weightloss. The active suspension weight reduction system is mounted on the action aids can be used in the course of the movement to provide users with suspension weight reduction. Through the linear actuator to track the human body center of gravity up and down to provide the user with different suspension weightloss, to achieve mobile active suspension weightloss function. The design of the active suspension weight reduction system in the drive part of the using two sets of linear actuators for design, the two sets of linear actuators were mounted on the rear side of the both sides of the column, figure 11 is a linear actuator entity photo , The rated speed of 600 rpm, with 40: 1 reduction ratio and 3mm pitch of the Acme thread screw (ACME), can produce a maximum of 1200N thrust and 1200N self-locking force, Its telescopic movement speed Up to 7mm / sec, can provide a constant weightloss and support the weight of the suspension weight reduction system. With collocation the research and development of JIHSENSE company, models are S-100 and JS-101 Rally Sensors and Signal Amplifiers. The tension sensor is connected with the stainless steel square tube and the medical grade suspension strap respectively, can immediately measure the change in gravity, and the output signal of the tension sensor is inputted into the embedded system by the amplifier, and then the control signal is output by the embedded system to the linear actuator of the drive plate to close the loop control mode to achieve gait training and walking auxiliary process of active suspension weightloss.
Figure 11：A linear actuator entity photo
Ⅳ. control the design
Intelligent mobile multi-functional gait training system is composed of embedded system and touch-type tablet computer. The control system uses National Instruments' embedded system NI myRIO-1900 as the core, as shown in Figure 12. myRIO is an innovative platform, equipped with the latest Zynq integrated system single chip (SoC), dual Core ARM Cortex A9 Processor with FPGA Chip, there are about 28,000 configurable logical units,10 analog input channels (AI), 6 analog output channels (AO), Audio I / O channels, and 40 groups of digital input / output (DIO) channels, Its built-in Wi-Fi, 3-axis acceleration gauge, 256MB RAM and 5 volt power output. Host side, Real-time end and FPGA-side integration in the Windows PC-related applications, and the establishment of a database and human-computer interface, the platform provides a different signal capture format and program development, to meet the needs of different users. Embedded system to A / O, AI, DIO and LabVIEW system I / O signal capture, conversion and decoding, and WiFi wireless communication and touch the Tablet PC data transmission, to achieve intelligent mobile multi-function step State training system for immediate control. Figure 13 for the electronic control system architecture.
Figure 12：NI myRIO
Figure 13：The electronic control system architecture
ⅰ. Design of wearable exoskeleton booster leg controller
In the trajectory tracking control of the wearable exoskeleton leg, it is required that the leg must be corrected at the specified time to the specified position specified by the gait parameters. When the gait movement, the human body lower limb joint angle constantly in the correction and change, so the control system design needs to change the angle of rotation of the joint discretization, to obtain a comparison of system control. As the wearable exoskeleton help legs are flat motors and harmonic reducer as a drive, therefore, It is necessary to change the angle of each joint to the corresponding motor rotation angle change, of the external skeleton to help the leg trajectory tracking to provide the target track. So the creative design of the PID controller for the external skeleton of the leg trajectory tracking control compensation, to reduce the difficulty of the actual implementation of the controller. the creation of the first joint position control to confirm the control performance, and then track the tracking control, include: single leg double joint, one leg three joints and legs six joints of the track gait control.
ⅱ. Controller design for mobile suspension weight reduction support system
Mobile active suspension support system in addition to the size of the weightloss in addition to the impact of the load, but also with the patient's gait frequency, step size, body weight and height. Therefore, in the reduction of gravity control need to consider the patient's own factors.In order to provide accurate weightloss support force, the creation of the feedback signal by pulling the sensor,the design for the waist suspension of the PID controller, the closed circuit control of the weight reduction system, for the weight reduction system of the closed circuit control, so that linear actuators can be in different patients for gait training or action assistance,for patients with different weights,under different weightloss conditions,the closed loop control of the weight support system is carried out. Patients can be based on their own conditions to set the weight reduction, standing or walking, to provide static or dynamic suspension weight control, so that patients in the course of walking training can be assured and safe for gait training.
Ⅴ. creative description
"Smart mobile multi-functional gait training system" using a composite structure design, so that rehabilitation can also be outdoors, in addition to gait training to meet the needs of walking dysfunction and gait training, but also for the elderly frail and lower limb weakened to provide walking assistance to achieve lower limb gait training and action-assisted multi-in-one ultra-lightweight intelligent design. It is of great significance to design action armor with lower limb gait training function to help walk the disabled to establish a confidence in the re-walk and to improve the quality of life. The creation of biased against paralysis, frail older age and lower extremity weakness of lower extremity gait training for people with walking assist demand, using theoretical analysis, institutional dynamic simulation, prototype system production and experimental research method, according to human body lower limb rehabilitation medicine theory, this paper presents a design scheme of intelligent mobile multi - function gait training system which combines the external bone of the lower limb, the active suspension weightloss and the action auxiliary function, based on the law of human gait movement, kinematics analysis and dynamic simulation of the mechanism are carried out. And the use of control technology, NI myRIO system construction, to achieve the action and rehabilitation training both works, completed the lower extremity exoskeleton and active suspension weight reduction system embedded control system design, automation of mobility aids and lower extremity gait training and use for the family-oriented model brings diversity and innovation, also reduce the rehabilitation of the therapist's physical burden, speed up the recovery rate of patients, to improve the quality of life of patients and reduce the social burden of great value.
Ⅵ. Discussion
The aim is actually to design the production and control of the "Smart mobile multi-functional gait training system", to help patients with lower limb gait training. In the process of design and actual production, the goal function can be successfully achieved by many factors, including: Mobile aid, exoskeleton legs, mobile suspension weight support system and PID controller design, Solve these problems in order to make intelligent mobile multi-functional gait training system with a complete auxiliary system, and can provide timely assistance to patients. Overall, in the design and development of the intelligent mobile multi-function gait training system, in order to achieve the final functional requirements, the main future major optimization objectives are as follows:
ⅰ.To assist patient in the strength of regulation
For the lower extremity exoskeleton of the walking auxiliary and gait training mode, in each of the walking process provided by the assist is the same. Therefore, the future can consider the use of intelligent control strategy, according to the human body movement to adjust the walking power immediately.
ⅱ.Mechanical structure design and system and human coordination
For the walking dysfunction and gait training needs, to truly reflect the actual movement of the lower limbs is very difficult, lower extremity external skeletal trajectory is based on normal gait trajectory characteristics of planning, and did not consider the patient's lower limb muscle strength The influencing factors. Therefore, the future has to be based on the system structure and the actual factors, detailed modeling and analysis, and consider the lower extremity exoskeleton wear comfort, safety and stability, and further optimize the structural design of lower extremity exoskeleton to make the body lightweight.
ⅲ. System development and experiment
Because of the gait training system of the wearable exoskeleton can not be provided by the actual patient with gait data and related experiments during the experiment, how to analyze and improve the system with the experimental data of the patients and normal people so as to meet the needs of the patients Operational requirements of the standard, but also must be discussed.
ⅳ. Optimization of action aids in rugged terrain
In order to make the action aids in a variety of different road, to achieve a smooth control effect,according to the slope of the road to adjust the motor output torque and speed,therefore. In the future action of auxiliary equipment can be installed tilting instrument feedback slope of the road.To enhance or reduce the motor torque and speed basis.
Link to Video
https://www.youtube.com/watch?v=Uxm82wIkb5M&list=PLz5Gtgf4jYDoM3MlZNM4ph81U1vvE3yYe&index=1
