scholarly journals Bionic design and analysis of a multi-posture wheelchair

2022 ◽  
Vol 13 (1) ◽  
pp. 1-13
Author(s):  
Qiaoling Meng ◽  
Mingpeng Jiang ◽  
Zongqi Jiao ◽  
Hongliu Yu
Keyword(s):  
Coupling Model ◽  
Functional Requirements ◽  
Human Beings ◽  
Transformation Mechanism ◽  
Nonlinear Constraint ◽  
Joint Rotation ◽  
Rotation Center ◽  
Natural Motion ◽  
Systems Software ◽  
Body Joints

Abstract. Posture transformation is an essential function for multi-posture wheelchairs. To improve the natural motion in posture transformation that is a popular problem in the design of multi-posture wheelchairs because the current wheelchair's posture transformation mechanism cannot remain consistent between the rotation center of the wheelchair and the rotation center of the human body joints. This paper proposes a sitting–standing–lying three-posture bionic transformation mechanism for a smart wheelchair. A human–wheelchair coupling model is described and analyzed according to the biomechanical characteristics of the posture transformation of human beings and their functional requirements. The configuration of the transformation mechanism is chosen by comparing the trails of the wheelchair rotation centers and the corresponding human joint rotation centers. The kinematics of the optimized configuration are discussed in detail to obtain the most bionic motion performance using the multivariable nonlinear constraint optimization algorithm. Finally, the mechanism is designed, and its posture transformation performance is simulated and verified using Adams (Automatic Dynamic Analysis of Mechanical Systems) software.

Design of an Ankle Rehab Robot With a Compliant Parallel Kinematic Mechanism

2020 ◽  
Author(s):  
Nishant Jalgaonkar ◽  
Adam Kim ◽  
Shorya Awtar
Keyword(s):  
Degrees Of Freedom ◽  
Functional Requirements ◽  
Key Factors ◽  
Center Of Rotation ◽  
Ankle Motion ◽  
Natural Motion ◽  
Parallel Kinematic Mechanism ◽  
Parallel Kinematic ◽  
Kinematic Mechanism ◽  
Clinical Adoption

Abstract In this paper, we present the design of a novel ankle rehabilitation robot (ARR), called the Flex-ARR, that employs a compliant parallel kinematic mechanism (PKM) with decoupled degrees of freedom. The Flex-ARR is designed to collocate the biological center of rotation of the ankle with that of the robot’s center of rotation to allow natural ankle motion. While multiple ARR designs have been developed in research labs and some are commercially available, their clinical adoption has been limited because they do not emulate the natural motion of the ankle. The Flex-ARR leverages a unique PKM design that uses compliance to absorb minor misalignments between the center of rotation of the ankle and the robot, thereby allowing natural ankle motion. Also, because of its unique design, the PKM inherently accommodates variations in user foot sizes with minimal adjustments. The Flex-ARR is designed to provide multiple training modes that allow for both rehabilitation and assessment modalities. This paper provides a review of the literature to identify the key factors that have limited the clinical adoption of existing ARRs. Based on this, functional requirements and design specifications for an optimal ARR are defined. This is then used to develop a design strategy, followed by conceptual and detailed design.

scholarly journals Real-Time Estimation of Glenohumeral Joint Rotation Center With Cable-Driven Arm Exoskeleton (CAREX)—A Cable-Based Arm Exoskeleton

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Ying Mao ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Real Time ◽  
Glenohumeral Joint ◽  
Kinematic Model ◽  
Estimation Method ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Joint Rotation ◽  
Rotation Center ◽  
Arm Rehabilitation ◽  
Novel Approach

In the past few years, the authors have proposed several prototypes of a Cable-driven upper ARm EXoskeleton (CAREX) for arm rehabilitation. One of the assumptions of CAREX was that the glenohumeral joint rotation center (GH-c) remains stationary in the inertial frame during motion, which leads to inaccuracy in the kinematic model and may hamper training performance. In this paper, we propose a novel approach to estimate GH-c using measurements of shoulder joint angles and cable lengths. This helps in locating the GH-c center appropriately within the kinematic model. As a result, more accurate kinematic model can be used to improve the training of human users. An estimation algorithm is presented to compute the GH-c in real-time. The algorithm was implemented on the latest prototype of CAREX. Simulations and preliminary experimental results are presented to validate the proposed GH-c estimation method.

Real-Time Estimation of Glenohumeral Joint Rotation Center With CAREX: A Cable-Based Arm Exoskeleton

2012 ◽  
Author(s):  
Ying Mao ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Real Time ◽  
Healthy Subjects ◽  
Degrees Of Freedom ◽  
Glenohumeral Joint ◽  
Kinematic Model ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Experimental Results ◽  
Joint Rotation ◽  
Rotation Center

In the past few years, the authors have proposed several prototypes of a Cable-driven upper ARm EXoskeleton (CAREX) for arm rehabilitation. The key advantages of CAREX over conventional exoskeletons are: (i) It is nearly an order of magnitude lighter. (ii) It does not have conventional links and joints, hence does not require joint axes alignment and segment lengths adjustment. (iii) It does not limit the natural degrees-of-freedom of the upper limb. (iv) The structure of the exoskeleton is novel as the cables are routed from the proximal to the distal segments of the arm. Preliminary experimental results with CAREX on a robotic arm and on healthy subjects have demonstrated the effectiveness of the exoskeleton within “assist-as-needed” training paradigm. In this paper, we propose a novel approach to estimate the glenohumeral joint rotation center (GH-c) using measurements of shoulder joint angles and cable lengths. This helps in locating the glenohumeral joint rotation center appropriately within the kinematic model. As a result, more accurate kinematic model can be used to improve the training of human users. An estimation algorithm is presented to compute the GH-c in real-time. The algorithm was implemented on the latest prototype of CAREX which controls four degrees-of-freedom of the shoulder and elbow. Preliminary experiments were performed on two healthy subjects under two different scenarios: (i) GH-c was assumed to be a fixed point and (ii) GH-c was estimated using the proposed algorithm. Experimental results are presented to compare the two scenarios.

Design of an Ankle Rehab Robot With a Compliant Parallel Kinematic Mechanism

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Nishant Jalgaonkar ◽  
Adam Kim ◽  
Shorya Awtar
Keyword(s):  
Degrees Of Freedom ◽  
Functional Requirements ◽  
Detailed Design ◽  
Center Of Rotation ◽  
Ankle Motion ◽  
Natural Motion ◽  
Alignment Tool ◽  
Parallel Kinematic Mechanism ◽  
Parallel Kinematic ◽  
Kinematic Mechanism

Abstract In this article, we present the design of a novel ankle rehabilitation robot (ARR), called the Flex-ARR, that employs a compliant parallel kinematic mechanism (PKM) with decoupled degrees-of-freedom. While multiple ARRs have been developed and commercialized, their clinical adoption has been limited primarily because they do not emulate the natural motion of the ankle. Based on a review of existing ARRs and their limitations, this article defines functional requirements and design specifications for an optimal ARR. These are then used to develop a design strategy followed by conceptual and detailed design of a novel ARR. The proposed Flex-ARR is designed to collocate the biological center of rotation of the ankle with that of the robot's center of rotation to allow natural ankle motion. The strategic use of a compliant PKM in the Flex-ARR not only absorbs any residual misalignment between these two centers but also helps inherently accommodate variations in user foot sizes with minimal adjustments. Detailed design includes the ARR structure with adjustable features, compliant PKM optimization, sensor and actuator selection, and an alignment tool.

Development and Application of Design Concept Ontologies for Contextual Conceptualization

1998 ◽  
Author(s):  
Imre Horváth ◽  
Joris S. M. Vergeest ◽  
György Kuczogi
Keyword(s):  
Computer Aided Design ◽  
Design Solution ◽  
Functional Design ◽  
Functional Requirements ◽  
Human Beings ◽  
Design Concepts ◽  
High Level Modeling ◽  
Knowledge Intensive ◽  
High Level ◽  
Very High

Abstract This study focuses on two specific problems of knowledge intensive computer aided design: (a) how can design concepts be modeled and represented in a form that is understandable for human beings and can be processed by computers, (b) how can they be arranged in structures that enables a computer-based functional design of products. First, a methodology for definition of very high level modeling entities based on the ontology theory is presented. It formalizes design concepts in terms of all concerned entities, phenomena and situations and describes them by attributes, parameters and descriptors, respectively. Validity and interactions of design concepts are governed by constraints. The very high level modeling entities are arranged into domain oriented design ontologies based on their contents and semantic relationships. The formalism used for logical specification of design ontologies is based on a library of declarative expressions called ACN-Code. A design ontology lends itself to a specific knowledge base called associative concept network (ACN). The inference engine that works on an application oriented ACN selects the appropriate design concepts against a set of user specified functional requirements. Due to the pre-defined associations incomplete functional specifications can be completed to result in a fully functional design solution. The paper also presents an application example.

Axiomatic Design of Mechanical Systems

1995 ◽  
Vol 117 (B) ◽  
pp. 2-10 ◽  
Author(s):  
N. P. Suh
Keyword(s):  
Mechanical Design ◽  
Axiomatic Design ◽  
Axiomatic Approach ◽  
Independence Axiom ◽  
Functional Requirements ◽  
Process Systems ◽  
Information Axiom ◽  
Systems Software ◽  
Large Systems ◽  
Simple Systems

Design is done in many fields. Although the design practices in different fields appear to be distinct from each other, all fields use a common thought process and design principles. Consequently, the true differences between these fields are minor, often consisting of the definitions of words, the specific data, and knowledge. In comparison, larger differences can exist within a given field between simple systems and large systems due to the size and the time dependent nature of functional requirements. The axiomatic approach to design provides a general theoretical framework for all these design fields, including mechanical design. The key concepts of axiomatic design are: the existence of domains, the characteristic vectors within the domains that can be decomposed into hierarchies through zigzagging between the domains, and the design axioms (i.e., the Independence Axiom and the Information Axiom). Based on the two design axioms, corollaries and theorems can be stated or derived for simple systems, large systems, and organizations. These theorems and corollaries can be used as design rules or guidelines for designers. The basic concepts are illustrated using simple mechanical design examples. When design is viewed axiomatically, not only product design but all other designs, including design of process, systems, software, organizations, and materials, are amenable to systematic treatment.

scholarly journals Comparison of Two Methods for In Vivo Estimation of the Glenohumeral Joint Rotation Center (GH-JRC) of the Patients with Shoulder Hemiarthroplasty

PLoS ONE ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. e18488 ◽  
Author(s):  
Ali Asadi Nikooyan ◽  
Frans C. T. van der Helm ◽  
Peter Westerhoff ◽  
Friedmar Graichen ◽  
Georg Bergmann ◽  
...  
Keyword(s):  
Glenohumeral Joint ◽  
Joint Rotation ◽  
Shoulder Hemiarthroplasty ◽  
Rotation Center

Axiomatic Design of Mechanical Systems

1995 ◽  
Vol 117 (B) ◽  
pp. 2-10 ◽  
Author(s):  
N. P. Suh
Keyword(s):  
Mechanical Design ◽  
Axiomatic Design ◽  
Axiomatic Approach ◽  
Independence Axiom ◽  
Functional Requirements ◽  
Process Systems ◽  
Information Axiom ◽  
Systems Software ◽  
Large Systems ◽  
Simple Systems

Design is done in many fields. Although the design practices in different fields appear to be distinct from each other, all fields use a common thought process and design principles. Consequently, the true differences between these fields are minor, often consisting of the definitions of words, the specific data, and knowledge. In comparison, larger differences can exist within a given field between simple systems and large systems due to the size and the time dependent nature of functional requirements. The axiomatic approach to design provides a general theoretical framework for all these design fields, including mechanical design. The key concepts of axiomatic design are: the existence of domains, the characteristic vectors within the domains that can be decomposed into hierarchies through zigzagging between the domains, and the design axioms (i.e., the Independence Axiom and the Information Axiom). Based on the two design axioms, corollaries and theorems can be stated or derived for simple systems, large systems, and organizations. These theorems and corollaries can be used as design rules or guidelines for designers. The basic concepts are illustrated using simple mechanical design examples. When design is viewed axiomatically, not only product design but all other designs, including design of process, systems, software, organizations, and materials, are amenable to systematic treatment.

Estimations of the Spatial Distributions of Probabilities of the Occurrence of Destructive Earthquakes in the Sichuan Area Based on the Markov Chain–Linear Kriging Coupling Model

2020 ◽  
pp. 2150009
Author(s):  
Xue Yuan ◽  
Hu Dan ◽  
Liu Bin ◽  
Zeng Ling ◽  
Liang Yuan
Keyword(s):  
Spatial Distribution ◽  
Markov Chain ◽  
Natural Disasters ◽  
Markov Chain Model ◽  
Coupling Model ◽  
Standard Errors ◽  
Chain Model ◽  
Spatial Distributions ◽  
Human Beings ◽  
Global Science

An earthquake is one of the most serious natural disasters to human beings. The damage from destructive earthquakes is enormous, and the predictions and estimations of earthquakes are urgent challenges in global science fields. In view of the shortcomings of the Markov chain model and the kriging methods in the estimation of the probabilities of the occurrence of earthquakes, the Markov chain–linear kriging coupling model has been established. The model has been applied to estimate the spatial distribution of probabilities of the occurrence of destructive earthquakes of Ms4.5 and Ms6.0 and above in the Sichuan area. According to the estimations of this model, the maximum probabilities of the occurrence of earthquakes of Ms4.5 and Ms6.0 and above in the Changning area of Yibin are 9.59% and 0.46%, respectively, which are close to the frequencies of occurrences of earthquakes of corresponding magnitude in the series of earthquakes that occurred in June 2019 in the region. The validation indicates that the average standard errors of this model for estimating the probabilities of the occurrence of earthquakes of Ms4.5 and Ms6.0 and above are 4.96% and 0.81%, respectively, which are lower than the probability kriging, and the estimation of this model highlighted the high value region of the probabilities.

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