Kinematic analysis of a novel planar six-bar bionic leg

Xu, Ke; Liu, Haitao; Zhu, Xingqiao; Song, Yuanlin

doi:10.1007/978-3-030-20131-9_2

Cited by 10 publications

(6 citation statements)

References 9 publications

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“…Balancing six-bar mechanisms is highly appreciated in areas such as mobile robotics, since this type of linkage is used in humanoid robots [54] and bionic legs [55,56] as well as in rehabilitation engineering [57], in which balancing could minimize the reactions caused by the devices' motion, thus improving their performance and usability.…”

Section: Discussionmentioning

confidence: 99%

Complete Balancing of the Six-Bar Mechanism Using Fully Cartesian Coordinates and Multiobjective Differential Evolution Optimization

et al. 2022

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The high-speed operation of unbalanced machines may cause vibrations that lead to noise, wear, and fatigue that will eventually limit their efficiency and operating life. To restrain such vibrations, a complete balancing must be performed. This paper presents the complete balancing optimization of a six-bar mechanism with the use of counterweights. A novel method based on fully Cartesian coordinates (FCC) is proposed to represent such a balanced mechanism. A multiobjective optimization problem was solved using the Differential Evolution (DE) algorithm to minimize the shaking force (ShF) and the shaking moment (ShM) and thus balance the system. The Pareto front is used to determine the best solutions according to three optimization criteria: only the ShF, only the ShM, and both the ShF and ShM. The dimensions of the counterweights are further fine-tuned with an analysis of their partial derivatives, volumes, and area–thickness relations. Numerical results show that the ShF and ShM can be reduced by 76.82% and 77.21%, respectively, when importance is given to either of them and by 45.69% and 46.81%, respectively, when equal importance is given to both. A comparison of these results with others previously reported in the literature shows that the use of FCC in conjunction with DE is a suitable methodology for the complete balancing of mechanisms.

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Section: Discussionmentioning

confidence: 99%

Complete Balancing of the Six-Bar Mechanism Using Fully Cartesian Coordinates and Multiobjective Differential Evolution Optimization

et al. 2022

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“…The LMR proposed in [15] is shown in Figure 1(a). This robot is composed of eight planar six-bar linkages with different arrangements.…”

Section: Mathematic Modelingmentioning

confidence: 99%

“…A frame o xy  is established to measure all vectors, as shown in Figure 2. According to the kinematic modeling method of the Assur group presented in [15], the position vectors of points C, F and G can be directly obtained.…”

Section: Mathematic Modelingmentioning

confidence: 99%

“…Due to the intermittent motion of an LMR, there is an additional periodic movement that affects the accuracy of the image processing, thereby destabilizing visual servoing. Concerning the LMR developed in our previous work [15], this paper investigates a homography-based control scheme for the visual servoing of the robot. To reduce the influence of intermittent motion on image processing, an improved median filter algorithm is proposed by considering the kinematics of the LMR.…”

Section: Introductionmentioning

confidence: 99%

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Visual Servo Control of a Legged Mobile Robot Based on Homography

Liu¹,

Zhang²,

Wang³

et al. 2020

Preprint

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Due to the intermittent motion of a legged mobile robot, an additional periodic movement must be introduced that directly affects the image processing accuracy and destabilizes the visual servo control of the robot. To address this problem, this paper investigates a control scheme for the visual servoing of a legged mobile robot equipped with a fixed monocular camera. The kinematics of the legged mobile robot and homography- based visual servoing are employed to allow the robot to achieve the desired pose. By investigating the homographic relationship between the current and desired poses, the approach has no need for transcendental knowledge of the three-dimensional geometry of the target image. The feature points are directly extracted from the images to evaluate the homography matrix. To reduce the effects caused by the intermittent motions of the legged robot, an improved adaptive median filter is proposed. Furthermore, a sliding mode controller is designed, and a Lyapunov-based approach is used to analyze the stability of the control system. With the aid of CoppeliaSim software, a simulation is implemented to verify the effectiveness of the proposed method.

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“…However, both Theo Jansen's solution and Klann's inspired leg designs are very cumbersome, especially since they cannot be used as lower limb exoskeleton since it does not fit the size limit and overall dimension restrictions. Other related works include [28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Multicriteria Optimization of Lower Limb Exoskeleton Mechanism

Ibrayev,

Ibrayeva,

Rakhmatulina

et al. 2023

Applied Sciences

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Typical leg exoskeletons employ open-loop kinematic chains with motors placed directly on movable joints; while this design offers flexibility, it leads to increased costs and heightened control complexity due to the high number of degrees of freedom. The use of heavy servo-motors to handle torque in active joints results in complex and bulky designs, as highlighted in the existing literature. In this analytical study, we introduced a novel synthesis method with analytical solutions provided for synthesizing the lower-limb exoskeleton. Furthermore, we proposed a mathematical model of multicriteria optimization; as a result, we obtained several lower-limb exoskeleton mechanisms comprising only six links, well-suited to the human anatomical structure, exhibit superior trajectory accuracy, efficient force transmission, satisfactory step height, and having internal transfer segment of the foot.

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Kinematic analysis of a novel planar six-bar bionic leg

Cited by 10 publications

References 9 publications

Complete Balancing of the Six-Bar Mechanism Using Fully Cartesian Coordinates and Multiobjective Differential Evolution Optimization

Complete Balancing of the Six-Bar Mechanism Using Fully Cartesian Coordinates and Multiobjective Differential Evolution Optimization

Visual Servo Control of a Legged Mobile Robot Based on Homography

Multicriteria Optimization of Lower Limb Exoskeleton Mechanism

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