Student Projects
Contact Information
Country: Taiwan
Competition Year: 2017
University: Lunghwa University of Science and Technology
Team Members (with year of graduation):
Rui-Peng Chen(2017)
Kun-Hung Chi(2018)
Chia-Hung Wang(2019)
Hong-Ghang Huang(2019)
Faculty Advisers: Lian-Wang Lee
Email Address:
Daniel96604@gmail.com
Submission Language: English
Project Information
Title:
By using NI myRIO to control the platform pneumatically lower limb extremity gait training system
Description:
Uses NI myRIO the embedded system platform matching switch valve to carry on the air operated -like lower extremity gait training systems control design, and using the gas may for the attenuator and the actuating unit merit, achieves the mild-mannered recovery effect.
Products:
NI myRIO 1900 x2
LabVIEW 2014
The Challenge:
Lower extremity exoskeleton system majority of all uses the motor, the motor rigidity strongly, the weight is heavy, causes the patient not to be comfortable in the recovery, therefore we use the barometric pressure actuation, the use gas condensability, lets the patient experience the different recovery feeling.
The Solution:
Table of contents
2.1 Pneumatic Lower limb bones outside help and. 7
2.2 Pneumatic Active Suspension Weight Reduction System.. 9
2.3 Pressure center of gravity balance adjustment system.. 11
3.1 Pneumatic Lower limb bones outside help and. 12
3.2 Pneumatic active suspension weight reduction system.. 13
3.3 Air pressure balanced regulation system.. 15
4.1 Pneumatic Lower limb bones outside help and controller design. 19
4.2 Pneumatic active suspension weight reduction system controller design. 19
V、 Innovative features help. 20
This creation basis recovery medicine theory request, improves training system the motor actuation shortcoming (to include: The mechanism complex, the rigidity big also lacks the flexibility) is the essential target, the union pneumatic actuator technology characteristic, completes 'air operated -like lower limb gait training system' the design manufacture and the control. Figure 1 is the integrated system frame composition, including exterior frame, the barometric pressure center of gravity balance governing system, the barometric pressure reduction support system, the air operated -like lower limb exoskeleton boost leg and jogs machine, Figure 2 is the air operated -like lower limb gait training system entity picture. The control system mainly by the embedded controller, the encoder, the displacement and the pulling force sensory element is composed; Uses American commercial Country Instrument Limited liability company (NI) production myRIO of is the core, and controls the software composition control formula by the LabVIEW chart, carries on the system I/O signal to pick up, the transformation, the decoding and the control, the realization air operated -like lower limb gait training system driving-type suspension to reduce weight, the center of gravity balance adjustment, the exoskeleton gait and the hypothesized solid boundary gait simulation immediate control
According to recovery medicine theory, only then imitates the human body to walk as far as possible the gait to be able normally to achieve the best training effect. Therefore, when carries on the gait training must have a reduction system to reduce the patient both legs the stress, enables the training to achieve a better effect. At present in market condition existing lower limb gait training system, most carries on the actuation by the motor to reduce weight, but the motor provides it to reduce weight the position to be fixed, is unable when the patient center of gravity change provides the constant reduction strength. This creation union gas has characteristic of the condensability, by pneumatic actuator way to design and reduction the support system, reduction training system barometric pressure actuation, in structure bilateral symmetry stress even balance. In the training process may the condition hypothesis suitable reduction value which trains according to the patient lower limb, again actuates the reduction air cylinder by the myRIO controlling switch solenoid valve, realizes goal of the patient both legs stress reduction.
This creation basis human body center of gravity path change curve, designs and realizes one kind of passive adjustment human body center of gravity change system, realizes the human body center of gravity to stand normally and to walk in the process change rule. The Pressure center of gravity balance system by a quadrangle portal frame construction (frame four apexes by hinge joint may free rotation), a group of proportional type control organization (including three screw rods, three turntables and two barometric pressure cylinders) is composed, has the characteristic using the gas which may compress, the pressure which when the barometric pressure cylinder receives comes from human body center of gravity change produces, its can rest on the human body pressure the change automatic expansion and contraction. Therefore may the cushion sudden pressure, finally be able to reciprocate along with the human body center of gravity the passive realization human body center of gravity the path change, achieved between the exoskeleton and the outer support moves cushion. The air operated -like lower limb exoskeleton boost leg is one of entire gait training system important parts, must consider patient's gait characteristic and the human body lower limb movement characteristic, especially this system and human body direct contact, but also must base on kinesiology full factor and so on consideration security, flexibility and comfortableness influences. Therefore, this creation use barometric pressure cylinder composes 3 degrees of freedom the single leg exoskeleton systems, in picks up using the sensory element walks in the cycle the joint and the both feet condition, again leads the patient by the myRIO control exoskeleton boost leg to realize the gait training.
Figure1: Overall System Architecture Diagram
Figure2: Pneumatic lower extremity gait training system photo
Pneumatic lower limb external skeletal leg is in the entire gait training system important link, must consider patient's gait characteristic and the human body lower limb movement characteristic, the system must especially with the human body direct contact, therefore needs full factor and so on consideration security, flexibility and comfortableness influences. At present the lower limb exoskeleton actuation main dependence electrically operated motor completes, although has the control precision high merit, but its existence mechanism complex, the rigidity greatly with lacks shortcomings and so on flexibility, therefore obtains the good gait training effect with difficulty. Therefore, in order to overcome the related question that the motor actuates. This creation basis recovery medicine theory, utilization barometric pressure security, mild-mannered and dexterous characteristic, union pneumatic actuator technology in recovery medicine application superiority, by mild-mannered, safe and dexterous design concept, completes the lower limb exoskeleton boost leg the design and the entity manufacture, air operated -like lower limb exoskeleton boost leg entity picture as shown in Figure 3.
The mechanical design quality can affect the lower limb external skeletal leg’s function presentation; therefore, this creation is rests on following characteristic to carry on the air operated -like lower limb external skeletal leg’s design.
(1) Multi - agency degrees of freedom
The human body lower limb walks is normally the kind of degree of freedom resultant motion, the tradition uses Motor-driven mechanism, need to realize more degrees of freedom, needs to design a difficult and complex mechanism, is unable to meet the needs of physical training. This creation uses has the flexible pneumatic actuator system to carry on the actuation, may realize the movement characteristic, which formerly could not realize.
(2) Flexibility and safety
The present gait training organization mostly actuates by the motor, the system rigidity absorbs exterior impulse to be badly, and the sudden exterior impact will create the patient muscular tissue to damage. Pneumatic drive happen to can satisfy mild-mannered and the dexterous request, it doesn't need the deceleration mechanism also anti-overload capacity, compares with the hydraulic pressure actuator has the advantage of being clean.
(3) Institutional interference is small
The mechanism design can affect human body lower limb each joint with to walk the gait movement. Therefore the mechanism must conform to the human body lower limb structure and the joint mode of motion, reduces the patient lower limb and the exoskeleton interference, simultaneously selects the actuation part and sensory element quantity also must as far as possible reduction, achieve the increase system controllability and reduces the cost the goal.
(4) High performance ratio
The traditional gait training mechanism majority of energies all consume on the motor and the retro system, uses in Actuates the energy that the lower limb walks only to occupy always consumes energy the very small proportion. The lower limb exoskeleton boost leg is may dress, therefore must choose the weight light and can the effect scaled height of burst drive type.
(5) The length of the machine can be adjusted
For the patient's body type differences, in the design, lower extremity external skeleton help leg institutions need to have a range of adjustable, so that most patients can use.
Figure 3: Pneumatic Lower limb bones outside help and entities photo
According to recovery medicine theory, only then imitates the human body to walk as far as possible the gait to be able normally to achieve the best training effect. Therefore, when carries on the gait training must have a reduction system to reduce the patient both legs the stress, enables the patient a freer movement. At present in the market condition lower limb gait training system, generally uses the motor to actuate the reduction way, but the motor provides the reduction position be fixed, is unable when the patient center of gravity change provides the constant reduction strength. This creation use the compressibility of the gas, by design a support system by pneumatic actuator, system in structure bilateral symmetry, stress even balance. In the training process may the condition which trains according to the patient lower limb, establishes the suitable reduction value, again by the myRIO regulating **bleep** solenoid valve, goal of the impetus reduction barometric pressure cylinder realization driving suspension reduction, Figure 4 is the barometric pressure type driving suspension reduction system entity picture.
The barometric pressure type driving suspension reduction system may guarantee the stability, eliminates tumbles the fear and the balanced reflection. The reduction training enters the recovery period commonly used effective method for the lower limb disease patient. Its innovation spot is actuates by the air operated part, the union pneumatic actuator technology flexibility, the security and dexterous, and combine the driver and the attenuator, simulate the human body muscle to do move the effect, and NI myRIO realizes the air operated -like driving suspension reduction system immediate control.
Figure 4：Air-active suspension weight reduction system entities photo
This creation basis human body center of gravity path change curve, designs and realizes one kind of passive adjustment human body center of gravity change system, realizes the human body center of gravity to stand normally and to walk in the process change rule. The barometric pressure center of gravity balance governing system by a quadrangle portal frame construction (frame four apexes by hinge joint may free rotation), a group of proportional type control organization (including three screw rods, three turntables and two barometric pressure cylinders) is composed, has the characteristic using the gas which may compress, the barometric pressure cylinder receives comes from human body center of gravity change produces, its can rest on the human body pressure the change automatic expansion and contraction. Therefore may the cushion sudden pressure, finally be able to reciprocate along with the human body center of gravity the passive realization human body center of gravity the path change, achieved between the exoskeleton and the outer support moves the cushion, Figure 5 is the barometric pressure center of gravity balance governing system Entity picture.
Figure5: air pressure balanced regulation system entities photo
The electric motor drive system is rigid and easy for the patient to shock, if Generate shift mutations may cause patient injury, motor drive in rehabilitation training system its smooth and less secure; at the same time as the structure of motor drive system more complex, the increase in the number of bone help and degrees of freedom, the institutions are not easy to achieve lightweight. Because of gas transmission to meet security, smooth and compact the demand. Thus in order to overcome the problems related to motor drive with pneumatic drive technology in rehabilitation medical application advantage, the creation help under the Bone and body design requirements, combined with the pressure transmission technology, design and control air pressure cylinder to drive out the lower limb bones for legs. Air pressure cylinder to drive a motor convenient without gearbox, its anti-overload ability is strong, and compared to the hydraulic drive and has the advantage of clean air pressure transmission technology because of lower limb bones outside help and driver design preferences.
Pneumatic lower limb external skeletal leg outside help and mainly in air pressure cylinder, switch control valve in the rotation of the joints, the authoring single lever pressure cylinder on the driver design, as shown in Figure 6. Single lever pressure cylinder is commonly used air pressure cylinder of the electric motor in lightweight, simple structure, it is cheap and good benefits such as smooth and therefore the creation of single lever pressure cylinder for the joint institutions designed to replace traditional lower limb bones outside help and to electric motor drive design. Single lever through full bleed cylinder pressure generated output power and shift promote joint complete rotation movement.
Figure6: single lever pressure cylinder
Pneumatic active suspension weight reduction system is designed to ensure that the patient during training constant weight reduction, rehabilitation medicine theory in the gait training, less weight does not exceed its weight (included). Because of the weight of the majority is less than 100kg, so the maximum reduction of the average weight of less than 30 kg. This authoring picking 1.5 times the safety factor for design, based on standard pressure cylinders theoretical output pressure, the selected pressure weight support system of the air pressure in the cylinder bore and stroke for 50mm to 300mm. Figure 7 is a pressure-active suspension weight reduction system design figure. Pneumatically system reduce the size of its gravity with not only the switch solenoid valve inlet airflow and frequency response, also with the patient in the gait frequency, step and body weight and height. Therefore the actual weight control, consider not only the air pressure cylinder input pressure, also to take into account the factor the patient itself.
Figure 7: Air-active suspension system drive light weighting design diagram
Adjust the pneumatically balanced system design and need to be analyzed in the normal standing and walking, the focus of the highest and the lowest number of special status to the special status of the data to a different height people standing and walking track, the focus of the process as the focus adjustment based on the design. As a result of the left and right of the center of gravity of the human body and the front and rear change is far less than the focus up and down changes this creation only takes into account the changes in the upper and lower center of gravity, click the stroke cylinder rod pressure changes as your balance body input. To select the appropriate single lever pressure cylinders to adjust the Pneumatically balanced system of production and motion analysis, the creation by the desktop computing gas single lever stroke cylinder pressure changes:
Where are the parameters of the cylinder pressure As light weighting institutions in support of the Force and its size on the 0-300N,As the foot support by the above the parameter value to calculate the stroke cylinder pressure change. Your balance tuning principles as shown in Figure 8.
Figure 8: Adjusting your balance schematic diagram
The creation of national instruments with us business model is NI myRIO-1900 embedded system controller for embedded system development platform, Figure 9 myRIO-1900 entity diagram for NI, its CPU clock is 667Mhz, 512MB RAM. Overall system control to LabVIEW figure control software to finish coding system I/O signals capture, transform, decode and controlled for pneumatic lower extremity gait training system for real-time control. Figure 10-NI myRIO application architecture diagram, consists of three blocks that are windows PC-end, real-and the FPGA. In the Windows PC client can consolidate host port, real-time and FPGA-related applications and the establishment of databases and the HMI. Figure 11 to electrical system architecture diagram.
Figure 9: NI myRIO entity photo
Figure10: NI myRIO Application Architecture
Figure 11: Electrical Control System Architecture Diagram
In the pneumatic Lower limb bones help outside the track and trace control, requested the help of the legs of the time must be arrived at the specified location. When the thigh determines the leg movement in space, its location and lower leg joints turn angle to describe control system design and therefore need to change the rotation angle of the joints to discrete curve, to obtain system control contrast. The result of skeletal legs are to assist cylinder pressure as the actuator and therefore need to change the angle of the knuckles into the corresponding pressure cylinder shift changes and help for the Bone and Joint trajectory tracking target track. Transmission system pressure has a smooth and fast movement, but at the same time there are non-linear and so it becomes the creative design PID controller and feed forward compensation to the bone for the trajectory tracking control and compensation to reduce the actual controller of the difficulty of achieving. The creation to a single joint position control confirm control performance prior to the track of tracking control includes SINGLE LEG dual joints, single leg 3 legs 6 joints and joint track gait control.
The Pneumatically on-active suspension system weight reduction of the size of its gravity except the load impact with the patient in the gait frequency, step, body weight and height. Therefore reduced gravity control is also required to consider the patient's own factors. In order to provide accurate weight support, the creation by pulling the sensor feedback signals to vertical mounting design pressure cylinder PID controller for system closed-loop control of the pressure cylinders to different patients in the gait training for different weight of the patient weight in the different conditions for weight reduction support system closed-loop control. The patient according to their own conditions are less gravity, pressure system to users with less gravity control and keep the patient in walking training so that they can rest assured and security for gait training.
Hospitals and rehabilitation centers are set up a lot of training equipment, but the price of these devices are very expensive and the existing foreign gait training robots are to adult gait training is the largest and most of their lower extremities drive servo motor drive, which is characterized by high precision position control easy to control. Deficiencies is the most energy is consumed in the motor and gear systems make it energy efficiency ratio is low; and the system for motor drive rigid large-large to the patient, if the system is producing a shift to cause mutations patient legs or other organizations second damage and therefore the motorized gait training system for its smooth and less secure; at the same time as the structure of motor drive system more complex, the increase in the number of bone help and degrees of freedom, the agencies will become more difficult to achieve huge lightweight. Because of air driver will meet the security system, smooth and compact, and requirements. Thus to reduce the lower extremities gait training system of production costs and prices and improve the motor drive system lack of smooth, security and lightweight nature of the creative use of Pneumatically to drive the characteristics of the technical design of a new type of pneumatic lower extremity gait training system that not only reduce gait trainers a burden but also to improve patient with lower extremity gait training efficiency, relative to the motor drive of the limb gait training system, the creation of the design and development of pneumatic lower extremity gait training system for Pneumatically to the actuator cylinder in motor drive of the system to remove drive components need not less gear box, also have a simple and easy implementation agencies and anti-overload ability is strong, and in the NI myRIO embedded system platforms for control system design, in addition to the small size saves space and the cost of production is relatively low, so have market competitiveness. Compared to motor drive system for its smooth, security and light are great.
This authoring to design practical production and control the pneumatic 'Lower extremity gait training system for assisting patients with lower extremity gait training. In the design with the actual production process, the objective function can eventually successfully achieved depends on many factors including: Pneumatic leg bones help outside agencies, Pneumatic active suspension system, pressure regulating system of your balance and PID controller and feed forward compensation is designed to solve these problems for the pneumatic lower extremity gait training system complete the necessary lower extremity gait movement of the patient and can provide timely help. Overall, lower limbs in the pneumatic gait training system design and development process in order to achieve the final functional requirements, mainly the following difficulties:
(1) Control System Design
Pneumatic lower extremity gait training system is part of the scope of the training equipment, training of doctors and therapists generally lack the expertise related to the electrical system, the patient is relatively weak compared with normal people more vulnerable to operating mistakes so cause injury. Therefore, the design of the control system, the need to consider how to enable the system to ensure stability so that the operation can be as simple and user-friendly, and prevents the system went out of control and operating mistakes.
(2) gait training control policy
Hemiplegia patient in different training period of the lower extremities training have different needs. Therefore, Pneumatic lower extremity gait training system should have different gait training. The skeletal tie in with the movement of the body or on the bone-driven human movement or were driven out of skeletal movement, these capabilities are required to design different gait training control policy.
(3) System development and lab
As a result of pneumatic lower extremity gait training system during the lab may not have actual patient can tie in with the associated lab, so how to normal lab analysis data improvement to the system can be tailored to the needs of the patients for operation standards and must be discussed.
(4) Mechanical structure design and system and coordination
The skeletal mechanical structure to be able to provide sufficient power and to guarantee that it can maintain coordination and operator movement pace so that the difference between the minimum mutual interference. Therefore, the degree of freedom mechanical structure should be distributed and human movement joints structure and freedom while demand can vary according to different figures. The main difficulty is the bone mechanical structure design and freedom of move.
Movie reference joint:
https://www.youtube.com/watch?v=6WzUansWCd4&feature=youtu.be
