Study on a Two-Staged Control of a Lower-Limb Exoskeleton Performing Standing-Up Motion from a Chair

Jatsun, Sergey; Савин, Сергей; Yatsun, Andrey; Gaponov, Igor

doi:10.1007/978-3-319-31293-4_10

Cited by 8 publications

(3 citation statements)

References 19 publications

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“…Safety tests for long-term wearing of CUHK-EXO will also be conducted in the future, including any adverse effect in the hip, groin, penis, back, wrist, glutei, and scapula of the wearers. Jatsun et al [7] study on a lower limb exoskeleton performing standing up motion from a chair, and present a modified Jacobian transpose controller which allowed to implement the proposed combined control strategy. Karen Junius et al [8] present an exoskeleton to assist the wearer during sit to stand activities, which driven by compliant mechanically adjustable compliance and controllable equilibrium position actuator.…”

Section: Introductionmentioning

confidence: 99%

Performance analysis of unpowered lower limb exoskeleton during sit down and stand up

et al. 2021

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Conventional unpowered lower limb exoskeleton paid little attention to the metabolic cost of body during sit down (SD)/stand up (SU). The SD motion model and the motion characteristics of lower extremity are analyzed; then, a novel unpowered lower limb exoskeleton is proposed, and the contribution degree of muscles and stiffness of joints are used for determining the location and stiffness of energy storage element. The metabolic cost of relevant muscles in joints of the left leg is obtained based on Opensim software. The results show that metabolic cost of the gracilis, rectus femoris (RF), and long head of the biceps femoris decreased about 13%, 9%, and 68%, respectively. The total metabolic cost of body decreased about 14% during SD. However, the metabolic cost of the gracilis, RF, and long/short head of the biceps femoris increased about 22%, 33%, 208%, and 46%, respectively. And the metabolic cost of sartorius reduces about 39%, the total metabolic cost of body increased about 25.6% during SU, under the exoskeleton conditions. The results of this study can provide a theoretical basis for the optimal design of unpowered lower limb exoskeleton.

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Section: Introductionmentioning

confidence: 99%

Performance analysis of unpowered lower limb exoskeleton during sit down and stand up

et al. 2021

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“…The proper execution of this task needs an adequate degree of mobility and thus enables an individual to maneuver independently [ 2 ]. It is the task that needs balance, coordination among different segments of a body, and ample strength in the lower limb to achieve successful execution [ 3 ]. STS movement due to its complex nature is not yet fully understood [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

High-gain observer-based nonlinear control scheme for biomechanical sit to stand movement in the presence of sensory feedback delays

et al. 2021

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Sit-to-stand movement (STS) is a mundane activity, controlled by the central-nervous-system (CNS) via a complex neurophysiological mechanism that involves coordination of limbs for successful execution. Detailed analysis and accurate simulations of STS task have significant importance in clinical intervention, rehabilitation process, and better design for assistive devices. The CNS controls STS motion by taking inputs from proprioceptors. These input signals suffer delay in transmission to CNS making movement control and coordination more complex which may lead to larger body exertion or instability. This paper deals with the problem of STS movement execution in the presence of proprioceptive feedback delays in joint position and velocity. We present a high-gain observer (HGO) based feedback linearization control technique to mimic the CNS in controlling the STS transfer. The HGO estimates immeasurable delayed states to generate input signals for feedback. The feedback linearization output control law generates the passive torques at joints to execute the STS movement. The H2 dynamic controller calculates the optimal linear gains by using physiological variables. The whole scheme is simulated in MATLAB/Simulink. The simulations illustrate physiologically improved results. The ankle, knee, and hip joint position profiles show a high correlation of 0.91, 0.97, 0.80 with the experimentally generated reference profiles. The faster observer dynamics and global boundness of controller result in compensation of delays. The low error and high correlation of simulation results demonstrate (1) the reliability and effectiveness of the proposed scheme for customization of human models and (2) highlight the fact that for detailed analysis and accurate simulations of STS movement the modeling scheme must consider nonlinearities of the system.

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“…In paper [6], the application of neural networks for robot control is considered. Papers [7][8][9] are devoted to the management of walking systems during the implementation of different gaits.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Trainable Control System for Quadruped Robot

Dobrynin

2021

Electromechanics and Robotics

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In this article, we consider a trainable control system for a four-legged robot with 12 degrees of freedom. The control system consists of a training part built using mathematical methods of inverse kinematics and an intelligent learning JSM system. The training part of the system uses a virtual model of a four-legged robot to synthesize movements and works in simulation mode. The trained part of the system is built using the intelligent JSM decision-making method. The trained JSM system, thanks to its high speed, can control the walking robot in real time. A model of the control system is constructed, which is used to generate the gaits of a virtual robot model. The article describes the operation of the control system in training mode and in working mode. Simulation of the robot control system showed a high learning rate. The article considers the variants of static and dynamic stability of the robot. The calculated parameters of the diagonal gait of a four-legged robot are given.

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Study on a Two-Staged Control of a Lower-Limb Exoskeleton Performing Standing-Up Motion from a Chair

Cited by 8 publications

References 19 publications

Performance analysis of unpowered lower limb exoskeleton during sit down and stand up

Performance analysis of unpowered lower limb exoskeleton during sit down and stand up

High-gain observer-based nonlinear control scheme for biomechanical sit to stand movement in the presence of sensory feedback delays

Simulation of Trainable Control System for Quadruped Robot

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