Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Investigations Of A Novel Lower Limb Exoskeleton Control Strategy
Download Investigations Of A Novel Lower Limb Exoskeleton Control Strategy full books in PDF, epub, and Kindle. Read online Investigations Of A Novel Lower Limb Exoskeleton Control Strategy ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Investigations of a Novel Lower-limb Exoskeleton Control Strategy by : Nathan Roy Quinn
Download or read book Investigations of a Novel Lower-limb Exoskeleton Control Strategy written by Nathan Roy Quinn and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A novel controller was developed with a single positional input to determine the torques for each joint of a hip-knee-ankle leg of an exoskeleton during stance, and a regenerative minimum jerk based swing control policy. Simulations were performed in MATLAB, and Simulink environments. These simulations involved using a dynamic model to evaluate if the novel controller could produce natural gait patterns. Additionally, simulations evaluating regenerative minimum jerk methods were performed in Simulink to investigate swing control applicability. The stance control results demonstrated that proper progression through stance sub-phase is generated along with predictable torque outputs, however, the lack of synchronization between legs leads to uncoordinated gait. Swing control simulations demonstrated successful implementation of a regenerative minimum jerk control policy on a three degree-of-freedom leg. Moving forward, a high-level controller could be used to finalize the control framework by ensuring synchronization between the independent legs."--Page ii.
Book Synopsis Control Strategies for Robotic Exoskeletons to Assist Post-Stroke Hemiparetic Gait by : Julio Salvador Lora Millán
Download or read book Control Strategies for Robotic Exoskeletons to Assist Post-Stroke Hemiparetic Gait written by Julio Salvador Lora Millán and published by Springer Nature. This book was released on with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wearable Robotics written by Jacob Rosen and published by Academic Press. This book was released on 2019-11-16 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wearable Robotics: Systems and Applications provides a comprehensive overview of the entire field of wearable robotics, including active orthotics (exoskeleton) and active prosthetics for the upper and lower limb and full body. In its two major sections, wearable robotics systems are described from both engineering perspectives and their application in medicine and industry. Systems and applications at various levels of the development cycle are presented, including those that are still under active research and development, systems that are under preliminary or full clinical trials, and those in commercialized products. This book is a great resource for anyone working in this field, including researchers, industry professionals and those who want to use it as a teaching mechanism. Provides a comprehensive overview of the entire field, with both engineering and medical perspectives Helps readers quickly and efficiently design and develop wearable robotics for healthcare applications
Book Synopsis sEMG-based Control Strategy for a Hand Exoskeleton System by : Nicola Secciani
Download or read book sEMG-based Control Strategy for a Hand Exoskeleton System written by Nicola Secciani and published by Springer Nature. This book was released on 2021-11-22 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on the design and testing of an sEMG-based control strategy for a fully-wearable low-cost hand exoskeleton. It describes in detail the modifications carried out to the electronics of a previous prototype, covering in turn the implementation of an innovative sEMG classifier for predicting the wearer's motor intention and driving the exoskeleton accordingly. While similar classifier have been widely used for motor intention prediction, their application to wearable device control has been neglected so far. Thus, this book fills a gap in the literature providing readers with extensive information and a source of inspiration for the future design and control of medical and assistive devices.
Book Synopsis Novel Control for a Post-Stroke Gait Rehabilitation Exoskeleton by : Robert Trott
Download or read book Novel Control for a Post-Stroke Gait Rehabilitation Exoskeleton written by Robert Trott and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stroke is the second highest cause of death worldwide and the third leading cause of adult disability across all age brackets. Recovering gait following stroke is a major goal of patients, and hence rehabilitation, as it is central to many activities of daily living. Of the different treatment modalities, robotic assisted gait training is growing in popularity, but is still considered complementary to, and not substitute for conventional therapies comprising physiotherapy, overground walking and body weight supported treadmill training. The potential advantages that lower limb robotics bring to neurorehabilitation over conventional therapies include, higher dosage, specificity, improved consistency, and duration, though these benefits have been slow to manifest. Exoskeletons are well placed to provide these benefits, as well as environmental variation and task salience if they can be used away from outpatient settings. Control strategies that may be enhancing of recovery are often confined to stationary exoskeletons, and the control of mobile exoskeletons is only loosely related to gait, if at all, which limits rehabilitation outcomes. -- The primary aim of this PhD thesis was to develop an adaptive, user-initiated gait Controller that aims to target a novel neural recovery pathway. The Controller would use a robotic exoskeleton, with the intention of developing novel neuroplasticity that is beneficial for gait and would be permissive of simultaneous control of hip and knee posture. A theoretical framework based on the principles of neuroplasticity was proposed that seeks to bring higher engagement, task variance, and volition to gait rehabilitation. This framework considers stroke and rehabilitation timelines and the interaction of the proposal with existing theory, how beneficial neuroplasticity may manifest, and how the proposal may be detrimental. A comprehensive survey of candidate lower limb devices followed (164 devices), to understand exactly what features are compatible, complementary, or contradictory to the proposed control method, and to understand the implications the various specifications have. Specifically, it was found that ambulating exoskeletons that can move around the environment were preferred for their ability to be used in the community and the home, and that extended joint range of motion will be permissive of activities that are supportive of gait such as sit-to-stand and stair ascent/descent. Of the various control systems that have been implemented with exoskeleton devices, trajectory control, where motion is enforced on the limb by the exoskeleton, is preferred. -- The method of control was assessed for suitability as a gait controller through a participant study (n = 21). Participants were asked to reproduce the motion required for the controller, and with minor modification to participant motion it was shown that reliable control signals can be obtained. The remainder of the thesis applies the learnings of the previous stages in the development of the Controller and an accompanying Sensor. The custom Sensor was designed with a small form factor to be applied on the Controller. The thesis concludes with an implementation of the Controller and a successful demonstration of the proposed concept, where the control signals are reproduced on a scale lower limb exoskeleton. The full technical detail and specification of the Controller, and the custom position Sensor developed specific for this application, are presented as part of this work. -- This work has added a new theoretical framework for gait control following stroke and has added technological capability to implement the proposal. It is the primary recommendation of this PhD that the novel control method be tested further with participant studies and that the component hardware be developed further. Therapies targeting novel recovery mechanisms breathe fresh air into rehabilitation and may inspire other new treatments, and future funded work originating from this PhD will see the concept tested with a chronic stroke population, using an ambulating exoskeleton and the Controller.
Book Synopsis Interfacing Humans and Robots for Gait Assistance and Rehabilitation by : Carlos A. Cifuentes
Download or read book Interfacing Humans and Robots for Gait Assistance and Rehabilitation written by Carlos A. Cifuentes and published by Springer Nature. This book was released on 2021-09-16 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concepts represented in this textbook are explored for the first time in assistive and rehabilitation robotics, which is the combination of physical, cognitive, and social human-robot interaction to empower gait rehabilitation and assist human mobility. The aim is to consolidate the methodologies, modules, and technologies implemented in lower-limb exoskeletons, smart walkers, and social robots when human gait assistance and rehabilitation are the primary targets. This book presents the combination of emergent technologies in healthcare applications and robotics science, such as soft robotics, force control, novel sensing methods, brain-computer interfaces, serious games, automatic learning, and motion planning. From the clinical perspective, case studies are presented for testing and evaluating how those robots interact with humans, analyzing acceptance, perception, biomechanics factors, and physiological mechanisms of recovery during the robotic assistance or therapy. Interfacing Humans and Robots for Gait Assistance and Rehabilitation will enable undergraduate and graduate students of biomedical engineering, rehabilitation engineering, robotics, and health sciences to understand the clinical needs, technology, and science of human-robot interaction behind robotic devices for rehabilitation, and the evidence and implications related to the implementation of those devices in actual therapy and daily life applications.
Book Synopsis On the Dynamics and Control of a Medical Exoskeleton by : Dong Jin Hyun
Download or read book On the Dynamics and Control of a Medical Exoskeleton written by Dong Jin Hyun and published by . This book was released on 2012 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of passive orthoses have been developed to provide gait assistance and rehabilitation for individuals who have lost the ability to walk. However, the required metabolic cost for legged mobility with conventional orthoses is huge, preventing its daily use. Using the forces/torques generated by external actuators is one of the effective ways to solve the problem induced from the considerable effort required for orthotic gait. For that, design of a compact, efficient and light weight actuation system and its delicate control are required. In Chapter 1, Powered Reciprocating Hip Orthosis, a novel hip actuator making use of the coupling hip mechanism of the reciprocating gait orthosis (RGO) is proposed. The RGO, a wearable and passive orthosis, provides paralyzed patients with hands-free standing and the ability for dynamic ambulation without any external actuation. Therefore, the mechanism of the RGO can be utilized effectively for improving the hip actuator design for a powered lower limb orthosis. Starting with this motivation, a powered limb orthosis combined with the conventional RGO was designed and its control structure was implemented on a paraplegic subject (T12 complete). First, a dynamic analysis is presented to identify and better understand the potential use of the RGO mechanism. For the analysis, the simple RGO dynamic model at a single support phase is obtained and its equations of motion are derived using Lagrange's equations of motion. Through the physical interpretation provided by the inverse dynamics, it is proved that the required maximum hip torque for stance phase is significantly decreased when the RGO hip coupling mechanism is applied. An unproved torso stability provided by the design is also investigated. Subsequently, overall control structure with a user-interface module is introduced to provide basic functions to the powered orthosis for locomotion. While implementing the designed orthosis with the human subject, a difficult problem on the dorsiflexion-activated passive knee orthosis of the conventional RGO is discussed and leads to Chapter 2: Friction Damping Control Knee Orthosis. A simple, but effective, microprocessor orthotic knee control method is presented with a novel knee joint design and an inertial measurement unit (IMU) sensor in Chapter 2. First, an electric hardware and a control structure with the IMU sensor are introduced. Next, to understand the knee dynamics and determine a control strategy, a lower extremity model is set up. Using this model, a dynamic analysis for ballistic walking with overshooting and circumduction of the hip joint motion, and downstairs walking is executed with the experimental hip motion data. Based on the observations for human hip joint motion and the obtained dynamic simulation results, a friction damping control method is proposed. Its implementation enables natural walking on level ground and provides the appropriate resistance of the knee joint in downstairs walking for assistance and safety to normal human subjects using the designed knee orthosis.
Book Synopsis Development and Control of a Pediatric Lower Limb Exoskeleton for Gait Guidance by : Anthony Clarence C. Goo
Download or read book Development and Control of a Pediatric Lower Limb Exoskeleton for Gait Guidance written by Anthony Clarence C. Goo and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several genetic, developmental and neurological disorders can cause various levels of gait impairment in the pediatric population. Powered lower limb orthoses, or exoskeletons, have recently been used to address gait impairment and afford therapists alternative solutions and strategies for gait therapy. Most exoskeleton research has focused on the adult population while the pediatric population remains underserved. The limitations of current pediatric exoskeletons make them impractical for use in both community and clinical settings. Furthermore, exoskeleton controllers suitable for these environments should promote human volitional control while guiding the subject towards a dynamically stable healthy gait pattern. This dissertation presents the design of a pediatric lower limb exoskeleton and the application of a virtual constraint-based controller on the device. First, a small and lightweight exoskeleton joint actuator capable of delivering the torque and power requirements needed to assist and guide the hip and knee joints was developed. Testing and in-air gait tracking of a model leg in a provisional orthosis demonstrated that the joint actuators were suitable for use in a pediatric exoskeleton. Second, an adjustable exoskeleton frame was designed and fabricated, and a human factors assessment of the fully assembled pediatric lower limb exoskeleton demonstrated that the device was lightweight, comfortable, easily adjustable and suitable for children. Third, a virtual constraint-based controller was applied on an underactuated adult exoskeleton. This initial investigation demonstrated that virtual constraint-based control guided the subject towards a dynamically stable gait in a time-invariant manner, provided greater volitional control to the subject and promoted active participation in the walking exercise. Finally, this dissertation research concluded with the application of a virtual constraint-based controller on the pediatric lower limb exoskeleton in treadmill walking experiments. The results showed that virtual constraint-based control reduced gait variability and the amount of robotic intervention applied relative to proportional-derivative control. Subject feedback also indicated that the virtual constraint-based controller was easier to use compared to time-based proportional-derivative control. This dissertation research demonstrates that the developed exoskeleton is suitable as an investigative platform for pediatric exoskeleton controllers and that virtual constraint-based controllers have potential for the rehabilitation and guidance of pediatric gait.
Book Synopsis Assistive Design and Multiaxis Self-tuning Control of a Novel Exoskeleton Robot Based on Fuzzy Logic Control in Gait Phase Detection for Rehabilitation of Lower Limb by : 李明展
Download or read book Assistive Design and Multiaxis Self-tuning Control of a Novel Exoskeleton Robot Based on Fuzzy Logic Control in Gait Phase Detection for Rehabilitation of Lower Limb written by 李明展 and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Control Strategies for a Minimally Actuated Medical Exoskeleton for Individuals with Paralysis by : Jason Ira Reid
Download or read book Control Strategies for a Minimally Actuated Medical Exoskeleton for Individuals with Paralysis written by Jason Ira Reid and published by . This book was released on 2012 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 265,000 individuals in the United States have a spinal cord injury. The wheelchair is currently the most prescribed mobility option for this population. Robotic exoskeleton devices are a promising alternative means of mobility that enable a paraplegic user to regain the physical and emotional health benefits of standing and walking. This dissertation will discuss novel gait strategies that were designed for a minimally-actuated medical exoskeleton device. Two novel stance control strategies will be presented that are designed to propel the exoskeleton and pilot forward out of double-stance. The first stance strategy relies on the movement of the pilot's torso as a means to dynamically propel the system forward through a step. Second, a more advanced strategy that propels the user forward while stabilizing their torso will also be proposed. Through the manipulation of lower extremity kinematics, the user can be propelled forward out of double-stance with an exoskeleton that only has actuation at the hips. Sequential methods of trajectory generation will be described for both strategies. Experimental results will be presented that support the efficacy for these stance strategies. In addition, this dissertation proposes an original sequential swing phase model. This model is used to produce a gait trajectory for the swing leg that dynamically controls an unactuated swing knee. A method for swing phase hip trajectory generation will be presented. Experimental results will be shown that validate the efficacy of the swing phase trajectory at producing a natural human-like swing phase from a swing leg that has no actuation at the knee. Extensive pilot testing of the medical exoskeleton in both structured and unstructured environments was completed. The results from these tests support the efficacy of the control algorithms and show great promise in the minimally actuated exoskeleton paradigm. This work enables a reduction in exoskeleton hardware complexity, reduced weight, and anticipated lower costs for end users so that more spinal cord injury patients may have greater access to this technology.
Book Synopsis Exoskeletons in Rehabilitation Robotics by : Eduardo Rocon
Download or read book Exoskeletons in Rehabilitation Robotics written by Eduardo Rocon and published by Springer. This book was released on 2011-02-02 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new technological advances opened widely the application field of robots. Robots are moving from the classical application scenario with structured industrial environments and tedious repetitive tasks to new application environments that require more interaction with the humans. It is in this context that the concept of Wearable Robots (WRs) has emerged. One of the most exciting and challenging aspects in the design of biomechatronics wearable robots is that the human takes a place in the design, this fact imposes several restrictions and requirements in the design of this sort of devices. The key distinctive aspect in wearable robots is their intrinsic dual cognitive and physical interaction with humans. The key role of a robot in a physical human–robot interaction (pHRI) is the generation of supplementary forces to empower and overcome human physical limits. The crucial role of a cognitive human–robot interaction (cHRI) is to make the human aware of the possibilities of the robot while allowing them to maintain control of the robot at all times. This book gives a general overview of the robotics exoskeletons and introduces the reader to this robotic field. Moreover, it describes the development of an upper limb exoskeleton for tremor suppression in order to illustrate the influence of a specific application in the designs decisions.
Book Synopsis Iterative Learning Control for Lower Limb Exoskeleton Robot by : Zhongyi Wang
Download or read book Iterative Learning Control for Lower Limb Exoskeleton Robot written by Zhongyi Wang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Autonomous Assistance-as-needed Control of a Lower Limb Exoskeleton with Guaranteed Stability by : Samuel Campbell
Download or read book Autonomous Assistance-as-needed Control of a Lower Limb Exoskeleton with Guaranteed Stability written by Samuel Campbell and published by . This book was released on 2020 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lower-limb stroke rehabilitation is physically demanding on therapists and requires the concerted effort of multiple staff members. Researchers have accordingly begun investigating the use of lower-limb exoskeletons for rehabilitation. Unfortunately, if the exoskeleton ensures the correct trajectory regardless of whether or not the user contributes effort, rehabilitation can be ineffective as the patient can begin to slack. Recent research suggests using assistance-as-needed control to facilitate functional motor recovery by only applying torques if the patient deviates too far from the desired trajectory. Assistance-as-needed control has been difficult to employ in lower-limb exoskeletons, however, due to the need to ensure stability. This work demonstrates how virtual constraint control—a method used in prostheses and assistive exoskeleton control with robust stability properties—can be combined with a velocity-modulated deadzone to ensure stability. The simulations suggest the method can accommodate a large deadzone while remaining stable across a range of gait pathologies.
Book Synopsis A Novel Approach to User Controlled Ambulation of Lower Extremity Exoskeletons Using Admittance Control Paradigm by : Kiran Kartika Karunakaran
Download or read book A Novel Approach to User Controlled Ambulation of Lower Extremity Exoskeletons Using Admittance Control Paradigm written by Kiran Kartika Karunakaran and published by . This book was released on 2016 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: The robotic lower extremity exoskeletons address the ambulatory problems confronting individuals with paraplegia. Paraplegia due to spinal cord injury (SCI) can cause motor deficit to the lower extremities leading to inability to walk. Though wheelchairs provide mobility to the user, they do not provide support to all activities of everyday living to individuals with paraplegia. Current research is addressing the issue of ambulation through the use of wearable exoskeletons that are pre-programmed. There are currently four exoskeletons in the U.S. market: Ekso, Rewalk, REX and Indego. All of the currently available exoskeletons have 2 active Degrees of Freedom (DOF) except for REX which has 5 active DOF. All of them have pre-programmed gait giving the user the ability to initiate a gait but not the ability to control the stride amplitude (height), stride frequency or stride length, and hence restricting users’ ability to navigate across different surfaces and obstacles that are commonly encountered in the community. Most current exoskeletons do not have motors for abduction or adduction to provide users with the option for movement in coronal plane, hence restricting user’s ability to effectively use the exoskeletons. These limitations of currently available pre-programmed exoskeleton models are sought to be overcome by an intuitive, real time user-controlled control mechanism employing admittance control by using hand-trajectory as a surrogate for foot trajectory. Preliminary study included subjects controlling the trajectory of the foot in a virtual environment using their contralateral hand. The study proved that hands could produce trajectories similar to human foot trajectories when provided with haptic and visual feedback. A 10 DOF 1/2 scale biped robot was built to test the control paradigm. The robot has 5 DOF on each leg with 2 DOF at the hip to provide flexion/extension and abduction/adduction, 1 DOF at the knee to provide flexion and 2 DOF at the ankle to provide flexion/extension and inversion/eversion. The control mechanism translates the trajectory of each hand into the trajectory of the ipsilateral foot in real time, thus providing the user with the ability to control each leg in both sagittal and coronal planes using the admittance control paradigm. The efficiency of the control mechanism was evaluated in a study using healthy subjects controlling the robot on a treadmill. A trekking pole was attached to each foot of the biped. The subjects controlled the trajectory of the foot of the biped by applying small forces in the direction of the required movement to the trekking pole through a force sensor. The algorithm converted the forces to Cartesian position of the foot in real time using admittance control; the Cartesian position was converted to joint angles of the hip and knee using inverse kinematics. The kinematics, synchrony and smoothness of the trajectory produced by the biped robot was evaluated at different speeds, with and without obstacles, and compared with typical walking by human subjects on the treadmill. Further, the cognitive load required to control the biped on the treadmill was evaluated and the effect of speed and obstacles with cognitive load on the kinematics, synchrony and smoothness was analyzed.
Book Synopsis Wearable Robotics by : Maria Chiara Carrozza
Download or read book Wearable Robotics written by Maria Chiara Carrozza and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reports on advanced topics in the areas of wearable robotics research and practice. It focuses on new technologies, including neural interfaces, soft wearable robots, sensors and actuators technologies, and discusses important regulatory challenges, as well as clinical and ethical issues. Based on the 4th International Symposium on Wearable Robotics, WeRob2018, held October 16-20, 2018, in Pisa, Italy, the book addresses a large audience of academics and professionals working in government, industry, and medical centers, and end-users alike. It provides them with specialized information and with a source of inspiration for new ideas and collaborations. It discusses exemplary case studies highlighting practical challenges related to the implementation of wearable robots in a number of fields. One of the focus is on clinical applications, which was encouraged by the colocation of WeRob2018 with the International Conference on Neurorehabilitation, INCR2018. Additional topics include space applications and assistive technologies in the industry. The book merges together the engineering, medical, ethical and political perspectives, thus offering a multidisciplinary, timely snapshot of the field of wearable technologies. .
Book Synopsis Comprehensive Control Strategies for a Seven Degree of Freedom Upper Limb Exoskeleton Targeting Stroke Rehabilitation by : Levi Makaio Miller
Download or read book Comprehensive Control Strategies for a Seven Degree of Freedom Upper Limb Exoskeleton Targeting Stroke Rehabilitation written by Levi Makaio Miller and published by . This book was released on 2012 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation control algorithms are developed and tested for the EXO-UL7 towards a control strategy for stroke rehabilitation. EXO-UL7 is a seven degree of freedom (Dof) powered upper limb exoskeleton that was initially designed at the University of Washington and further refined at the University of California Santa Cruz. Admittance control, swivel angle prediction and neural control of the device have been implemented and subjects tested performance of the device and control strategy. After an initial summery of the state of the art and details of the existing system. Each control strategy and performance from testing is explored. Admittance control uses force sensors on EXO-UL7 to control the movement of the device by moving in the direction that that user pressed on the device. Because EXO-UL7 is a redundant manipulator and supports the entire configuration of the arm, a single force sensor on the device end effector is not enough to fully define the movement. Additional force sensors on the device that are located at each attachment point of the machine interface allows for the full configuration of the device to be specified. This turns the under defined problem into an over defined problem (to many force signals for the number of Dof). Two strategies are developed to project the signals onto a seven degree subspace. The first adds the force vectors in task space then uses the Inverse kinematic to develop joint trajectories. The second uses the Jacoban transpose to map the forces first to instantaneous joint torques then the torques are added in joint space and finally joint trajectories are developed from joint torques. Six subjects performed a peg in hole experiment and it was found that task based admittance control had about 11\% lower interaction energy required to do the task. It was also shown that with both admittance controlers the subjects did the tasks slower then with no Control at all. Kinematic and dynamic constraints requced the bandwith of the system. To improve the bandwith, Predictive algorithms are employed. Swivel angle prediction is the first predictive algorithm implements to improve the performance of the device. With this control strategy the configuration of the redundant space is related to the end effector position. by observing human behavior it was noted that one of the fundamental task preformed by the human arm was to bring food to the mouth. By maximizing the manipulability of the device in the direction of the mouth, a simple stable closed form prediction of the configuration of the device was achived. Comparing movement from motion capture to predicted motion showed a good correlation and testing of the algorithm on the exoskeleton device was conducted. 4 Subjects conducted a peg in hole task. An 11.22\% reduction of interaction energy was achieved when compared to Admittance control alone. This algorthm can be used for motion folowwing as in teh current set up, or to predict where what the arm configuration should be when working with disabled populations. Although this method predicted motion very well, it only provided prodiction of the one Dof redundant space of the arm. To further extend the prediction capability and motion following of the device, neural control was implemented in which electro myography (EMG) is used to read the nerve impulsed to the muscle. Although this signal only relates muscle force to isometric muscle contraction, using other system parameters read from Exo-UL7 such as the joint, position and velocity, A Hill based muscle model predicts the muscle force and ultimately the muscle torque. Due to an inherent delay between when the nerve impulse can first be detected and when the muscle contracts (some where o the order of 50-100 ms) the motion can be predicted before the arm begins to move. The model has many variable that need to be predicted for each individual so before each subject test an parameter fitting is conducted. Four subjects preformed a peg in hole test. It was shown that the interaction power increased compared to admittance control, but the completion time decreased. With further examination in was noted that the interaction force and energy when using the neural control was the same as with the admittance control. This implies that with the same force we achieved a higher velocity, which means that the system had a higher overall gain. The performance gains were not uniform through out all the subjects. The parameter fit conducted for each subject did not guarantee convergence to even a local minimum and there is still opportunities to improve the system performance. Admittance control did a good job of motion following and neural and swivel prediction improved upon this control scheme. There is still further work to be done on the system. Currently using the systems that were build in this dissertation, a clinical trial for stroke rehabilitation is under way at the university of California San Fransisco.
Book Synopsis Robust and Versatile Control of Lower Limb Exoskeletons by : Wolfgang Franz Rampeltshammer
Download or read book Robust and Versatile Control of Lower Limb Exoskeletons written by Wolfgang Franz Rampeltshammer and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
