Design of a Wheelchair Robot for Active Postural Support

2018 ◽  
Author(s):  
Rosemarie C. Murray ◽  
Chawin Ophaswongse ◽  
Sunil K. Agrawal
Keyword(s):  
Motor Control ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Dynamic Range ◽  
Sagittal Plane ◽  
Control Architecture ◽  
Lateral Bending ◽  
Robotic Exoskeleton ◽  
Postural Support ◽  
And Control

This paper describes the design and control architecture of a novel Wheelchair-mounted Robot for Active Postural Support (WRAPS). The WRAPS is a robotic exoskeleton that allows limited degrees-of-freedom (DOFs) of the trunk relative to the pelvis. There are three DOFs in the sagittal plane of the human body and one in lateral bending. The work is motivated by the needs of individuals with impaired trunk motor control, who currently rely on the use of passive and predominantly static supports to maintain a static posture. These devices can be overly restrictive and inhibit the user in their activities of daily living (ADLs). The WRAPS is capable of supporting a human user within their active range of torso motion. It has the potential to assist users in their ADLs while encouraging a dynamic range of healthy postures.

Design of a Wheelchair Robot for Active Postural Support

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Rosemarie C. Murray ◽  
Chawin Ophaswongse ◽  
Sunil K. Agrawal
Keyword(s):  
Activities Of Daily Living ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Dynamic Range ◽  
Sagittal Plane ◽  
Control Architecture ◽  
Lateral Bending ◽  
Robotic Exoskeleton ◽  
Postural Support ◽  
And Control

This paper describes the design and control architecture of a novel wheelchair-mounted robot for active postural support (WRAPS). The WRAPS is a robotic exoskeleton that allows limited degrees-of-freedom of the trunk relative to the pelvis. There are three degrees-of-freedoms in the sagittal plane of the human body and one in lateral bending. The work is motivated by the needs of individuals with impaired trunk motor control, who currently rely on the use of passive and predominantly static supports to maintain a static posture. These devices can be overly restrictive and inhibit the user in their activities of daily living. The WRAPS is capable of supporting a human user within their active range of torso motion. It has the potential to assist users in their activities of daily living while encouraging a dynamic range of healthy postures.

scholarly journals Development of Underactuated Prosthetic Fingers with Joint Locking and Electromyographic Control

2013 ◽  
Vol 3 (1) ◽  
pp. 130 ◽  
Author(s):  
Bart Peerdeman ◽  
Stefano Stramigioli ◽  
Edsko E. G. Hekman ◽  
Dannis M. Brouwer ◽  
Sarthak Misra
Keyword(s):  
Control Systems ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Single Motor ◽  
Hand Prosthesis ◽  
And Control ◽  
Electromyographic Signals ◽  
Underactuated Finger

Modern hand prostheses possess a large number of degrees of freedom. These degrees of freedom cannot simply be actuated by a single motor each, since their combined size and weight would exceed the limitations of an anthropomorphic prosthesis. Some hand prostheses try to remedy this by way of underactuation of the fingers or addition of entirely passive fingers, but this reduces the hand's ability to execute different grasp types. We present a joint locking system, allowing certain degrees of freedom to be fixed during actuation of an underactuated finger. These locks are actuated by miniature solenoids, and allow the fingers to support a variety of grasp types. In this paper, these locks are implemented in a two-fingered prosthesis prototype, which is able to perform several grasping motions important for prosthesis users. This prototype is controlled by pre-recorded electromyographic signals, which control different grasp types and their opening/closing. Various grasping experiments show that the prototype is able to execute three essential grasp types for daily living with a single main actuator, and can be intuitively controlled by means of six different electromyographic signals. This prototype demonstrates new joint locking mechanisms and control systems that can provide an anthropomorphic, myoelectric hand prosthesis with minimal actuation and intuitive control.

scholarly journals 3D Quantitative Evaluation of Posture and Spine Proprioceptive Perception Through Instinctive Self-Correction Maneuver in Adolescent Idiopathic Scoliosis

2021 ◽  
Vol 9 ◽  
Author(s):  
Edyta Kinel ◽  
Moreno D’Amico ◽  
Piero Roncoletta
Keyword(s):  
Young Adults ◽  
Motor Control ◽  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Sagittal Plane ◽  
Body Posture ◽  
Published Data ◽  
Spine Shape ◽  
Correction Maneuver ◽  
And Control

BackgroundConservative treatment in the adolescent idiopathic scoliosis (AIS) population is based on individual proprioceptive and motor control training. Such training includes physiotherapeutic scoliosis-specific exercises (PSSEs) stimulating the individual capacity to perceive and control his/her posture, particularly the shape of the spine. However, limited knowledge about basic proprioception capability in AIS patients is reported in the literature.Questions(1) How do AIS patients, who did not receive any previous specific postural education treatment, perceive their posture and 3D spine shape? Are they able to modify their posture and 3D spine shape correctly through an instinctive self-correction (ISCO) maneuver? (2) Are posture and ISCO maneuver ability gender dependent in AIS patients? (3) Do AIS patients present different posture and spine shape characteristics as well as different ISCO ability compared with the healthy young adult population?MethodsCross-sectional observational study. 132 (75 females, 57 males) AIS patients’ posture and 3D spine shape have been measured comparing indifferent orthostasis (IO) (neutral erect posture) to ISCO using a non-ionizing 3D optoelectronic stereophotogrammetric approach. Thirteen quantitative biomechanical parameters described the AIS patients body posture. The statistical analysis was performed using a multivariate approach to compare genders in IO, ISCO, and AIS patients vs. healthy young adults–previously published data (57 females, 64 males).ResultsMales (87.7%) and females (93.3%) of AIS patients were unable to modify posture and 3D spine shape globally. AIS patients gender differences were found in IO, ISCO, and the comparison vs. healthy young adults. When changes occurred, subjects could not focus and control their posture globally, but only in a few aspects at a time.ConclusionSelf-correction maneuver producing an improvement in body posture and spine shape is not instinctive and must be trained. In such characteristics, AIS patients are not so dissimilar to healthy young adults. Sagittal plane control is the highest, but ISCO in AIS patients led to worsening in this plane. Control at the lumbar level is neglected in both genders. Such outcomes support the necessity of customized PSSEs to treat AIS patients. The 3D stereo-photogrammetric approach is effective in quantitatively describing the subject’s posture, motor control, and proprioception.

INTERSEGMENTAL COORDINATION IN LOWER EXTREMITIES AND MULTI-SEGMENTAL SPINE DURING DIFFERENT ACTIVITIES OF DAILY LIVING

2017 ◽  
Vol 17 (07) ◽  
pp. 1740015
Author(s):  
DAIQI GUO ◽  
SHENGZHENG KUAI ◽  
WENYU ZHOU ◽  
XINYU GUAN ◽  
ZHENHUA LIAO ◽  
...  
Keyword(s):  
Activities Of Daily Living ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Sagittal Plane ◽  
Principal Component ◽  
Human Movement ◽  
Stair Climbing ◽  
Motion Pattern ◽  
Level Walking ◽  
Lower Lumbar

Background: Human movement consists of numerous degrees of freedom (DOF). How the nervous system (NS) computes the appropriate command to coordinate these DOFs to finish specific tasks is still hotly debated. One common way to simplify the redundant DOFs is to coordinate multiple DOFs by combining them into units or synergies. The present study aimed to investigate the kinematic complexity of five activities of daily living (ADLs) and to detect the amount of kinematic synergy during every ADL and the relationship of the motion pattern between these ADLs. Method: Twenty-six able-bodied male individuals performed level walking, stair climbing, trunk bending, ipsilateral pick-up and contralateral pick-up in sequence. The segmental excursion of the thorax, upper lumbar, lower lumbar, pelvis, thigh and shank was calculated. Principal component analysis (PCA) was applied to determine the motion pattern of every ADL. Result: In the sagittal plane, trunk bending, ipsilateral pick-up and contralateral pick-up could be simplified by using one principal component (PC) with more than 95% variance accounted for (VAF). In addition, the motion pattern of every PC was similar among the three ADLs. Moreover, the angles between the vectors representing the first PC of the three ADLs were all less than 10[Formula: see text]. Level walking and stair climbing needed at least two PCs to reach 95% VAF. In addition, the motion pattern was different between the two ADLs. Moreover, the angle between the first PC of the two ADLs was around 90[Formula: see text]. In the coronal plane, the five ADLs except contralateral pick-up arrived at 90% VAF with two PCs. The motion pattern and the angle between the first PC both demonstrated larger differences among the five ADLs. Conclusion: Two PCs were essential to represent level walking and stair climbing, indicating a complex control strategy used by the NS. Trunk bending, ipsilateral pick-up and contralateral pick-up could be described with one PC in the sagittal plane, showing a strong coupling and simple motion pattern. In addition, the motion pattern varied considerably among these ADLs. The outcomes of this study can help clinicians to select suitable ADLs for the patients with various joint or disc diseases and to conduct corresponding functional test and rehabilitation.

Control Architecture and Control Laws Design for Multiple UAVs Formation Flight

2012 ◽  
Vol 246-247 ◽  
pp. 853-857
Author(s):  
Guang Lei Meng
Keyword(s):  
Degrees Of Freedom ◽  
Formation Flight ◽  
Control Architecture ◽  
Mathematical Representation ◽  
Control Laws ◽  
Multiple Uavs ◽  
Finite State ◽  
Aerial Vehicle ◽  
6 Degrees Of Freedom ◽  
And Control

An autonomous formation-flight method for multiple UAVs (Unmanned Aerial Vehicle) was designed. First the mathematical representation of formation shape was analyzed. Then the control architecture was devised for multiple UAVs formation flight based on finite state machine. The flight states of the wing UAV were built through the formation flight and the transformation relationships of these flight states were defined. So the automated transformation among these flight states could be achieved and the intelligence of the pilots could be mimicked by this way. Aiming at the typical flight state which is capable of maintaining the formation shape, the control laws were contrived for the wing UAVs. Finally, two nonlinear fighter models which have 6 degrees of freedom were selected to carry out autonomous formation-flight experiments. And the results show the control laws designed for maintaining the formation shape are valid.

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

scholarly journals A Tip–Tilt and Piston Detection Approach for Segmented Telescopes

Photonics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3
Author(s):  
Shun Qin ◽  
Wai Kin Chan
Keyword(s):  
Error Detection ◽  
Phase Retrieval ◽  
Dynamic Range ◽  
Detection Accuracy ◽  
Wavefront Sensing ◽  
Next Generation ◽  
Large Aperture ◽  
Detection Approach ◽  
Segmented Mirror ◽  
And Control

Accurate segmented mirror wavefront sensing and control is essential for next-generation large aperture telescope system design. In this paper, a direct tip–tilt and piston error detection technique based on model-based phase retrieval with multiple defocused images is proposed for segmented mirror wavefront sensing. In our technique, the tip–tilt and piston error are represented by a basis consisting of three basic plane functions with respect to the x, y, and z axis so that they can be parameterized by the coefficients of these bases; the coefficients then are solved by a non-linear optimization method with the defocus multi-images. Simulation results show that the proposed technique is capable of measuring high dynamic range wavefront error reaching 7λ, while resulting in high detection accuracy. The algorithm is demonstrated as robust to noise by introducing phase parameterization. In comparison, the proposed tip–tilt and piston error detection approach is much easier to implement than many existing methods, which usually introduce extra sensors and devices, as it is a technique based on multiple images. These characteristics make it promising for the application of wavefront sensing and control in next-generation large aperture telescopes.

scholarly journals DOES BRAIN ACTIVATION DURING FUNCTIONAL MOVEMENT TASKS DIFFERENTIATE BETWEEN GOOD AND BAD MOVERS? AN INTEGRATED NEUROIMAGING ASSESSMENT OF MOTOR CONTROL IN YOUNG ATHLETES

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0013
Author(s):  
Manish Anand ◽  
Jed A. Diekfuss ◽  
Dustin R. Grooms ◽  
Alexis B. Slutsky-Ganesh ◽  
Scott Bonnette ◽  
...  
Keyword(s):  
Motor Control ◽  
Range Of Motion ◽  
Brain Function ◽  
Sagittal Plane ◽  
Brain Activity ◽  
Frontal Plane ◽  
Acl Injury ◽  
Timing Error ◽  
Lingual Gyrus ◽  
Increased Activity

Background: Aberrant frontal and sagittal plane knee motor control biomechanics contribute to increased anterior cruciate ligament (ACL) injury risk. Emergent data further indicates alterations in brain function may underlie ACL injury high risk biomechanics and primary injury. However, technical limitations have limited our ability to assess direct linkages between maladaptive biomechanics and brain function. Hypothesis/Purpose: (1) Increased frontal plane knee range of motion would associate with altered brain activity in regions important for sensorimotor control and (2) increased sagittal plane knee motor control timing error would associate with altered activity in sensorimotor control brain regions. Methods: Eighteen female high-school basketball and volleyball players (14.7 ± 1.4 years, 169.5 ± 7 cm, 65.8 ± 20.5 kg) underwent brain functional magnetic resonance imaging (fMRI) while performing a bilateral, combined hip, knee, and ankle flexion/extension movements against resistance (i.e., leg press) Figure 1(a). The participants completed this task to a reference beat of 1.2 Hz during four movement blocks of 30 seconds each interleaved in between 5 rest blocks of 30 seconds each. Concurrent frontal and sagittal plane range of motion (ROM) kinematics were measured using an MRI-compatible single camera motion capture system. Results: Increased frontal plane ROM was associated with increased brain activity in one cluster extending over the occipital fusiform gyrus and lingual gyrus ( p = .003, z > 3.1). Increased sagittal plane motor control timing error was associated with increased brain activity in multiple clusters extending over the occipital cortex (lingual gyrus), frontal cortex, and anterior cingulate cortex ( p < .001, z > 3.1); see Figure 1 (b). Conclusion: The associations of increased knee frontal plane ROM and sagittal plane timing error with increased activity in regions that integrate visuospatial information may be indicative of an increased propensity for knee injury biomechanics that are, in part, driven by reduced spatial awareness and an inability to adequately control knee abduction motion. Increased activation in these regions during movement tasks may underlie an impaired ability to control movements (i.e., less neural efficiency), leading to compromised knee positions during more complex sports scenarios. Increased activity in regions important for cognition/attention associating with motor control timing error further indicates a neurologically inefficient motor control strategy. [Figure: see text]

scholarly journals Annular Defects Impair the Mechanical Stability of the Intervertebral Disc

2021 ◽  
pp. 219256822110060
Author(s):  
Jun-Xin Chen ◽  
Yun-He Li ◽  
Jian Wen ◽  
Zhen Li ◽  
Bin-Sheng Yu ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Degrees Of Freedom ◽  
Mechanical Stability ◽  
Biomechanical Testing ◽  
Bending Stiffness ◽  
Biomechanical Study ◽  
Torsional Stiffness ◽  
P Value ◽  
Lateral Bending ◽  
Flexion Extension

Study Design: A biomechanical study. Objectives: The purpose of this study was to investigate the effects of cruciform and square incisions of annulus fibrosus (AF) on the mechanical stability of bovine intervertebral disc (IVD) in multiple degrees of freedom. Methods: Eight bovine caudal IVD motion segments (bone-disc-bone) were obtained from the local abattoir. Cruciform and square incisions were made at the right side of the specimen’s annulus using a surgical scalpel. Biomechanical testing of three-dimensional 6 degrees of freedom was then performed on the bovine caudal motion segments using the mechanical testing and simulation (MTS) machine. Force, displacement, torque and angle were recorded synchronously by the MTS system. P value <.05 was considered statistically significant. Results: Cruciform and square incisions of the AF reduced both axial compressive and torsional stiffness of the IVD and were significantly lower than those of the intact specimens ( P < .01). Left-side axial torsional stiffness of the cruciform incision was significantly higher than a square incision ( P < .01). Neither incision methods impacted flexional-extensional stiffness or lateral-bending stiffness. Conclusions: The cruciform and square incisions of the AF obviously reduced axial compression and axial rotation, but they did not change the flexion-extension and lateral-bending stiffness of the bovine caudal IVD. This mechanical study will be meaningful for the development of new approaches to AF repair and the rehabilitation of the patients after receiving discectomy.

scholarly journals High-performance magneto-rheological clutches for direct-drive actuation: Design and development

2021 ◽  
pp. 1045389X2110069
Author(s):  
Sergey Pisetskiy ◽  
Mehrdad Kermani
Keyword(s):  
High Performance ◽  
Degrees Of Freedom ◽  
Dynamic Range ◽  
Complete Analysis ◽  
Mass Ratio ◽  
Direct Drive ◽  
Element Analysis ◽  
Prototype Development ◽  
Magneto Rheological ◽  
Hall Sensors

This paper presents an improved design, complete analysis, and prototype development of high torque-to-mass ratio Magneto-Rheological (MR) clutches. The proposed MR clutches are intended as the main actuation mechanism of a robotic manipulator with five degrees of freedom. Multiple steps to increase the toque-to-mass ratio of the clutch are evaluated and implemented in one design. First, we focus on the Hall sensors’ configuration. Our proposed MR clutches feature embedded Hall sensors for the indirect torque measurement. A new arrangement of the sensors with no effect on the magnetic reluctance of the clutch is presented. Second, we improve the magnetization of the MR clutch. We utilize a new hybrid design that features a combination of an electromagnetic coil and a permanent magnet for improved torque-to-mass ratio. Third, the gap size reduction in the hybrid MR clutch is introduced and the effect of such reduction on maximum torque and the dynamic range of MR clutch is investigated. Finally, the design for a pair of MR clutches with a shared magnetic core for antagonistic actuation of the robot joint is presented and experimentally validated. The details of each approach are discussed and the results of the finite element analysis are used to highlight the required engineering steps and to demonstrate the improvements achieved. Using the proposed design, several prototypes of the MR clutch with various torque capacities ranging from 15 to 200 N·m are developed, assembled, and tested. The experimental results demonstrate the performance of the proposed design and validate the accuracy of the analysis used for the development.

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