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Mechanism dimensional synthesis (a) four-bar linkage (b) crank L0 = L1 = L2 = L3 () í µí°´í µí°µ//í µí° ¶í µí°·, í µí°µí µí° ¶//í µí°´í µí°· () í µí°´í µí°µ ̅̅̅̅ + í µí°µí µí° ¶ ̅̅̅̅ = í µí°´í µí°· ̅̅̅̅ + í µí°·í µí° ¶ ̅̅̅̅ ()
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A walking machine (robot) is a type of locomotion that operates by means of legs and/or wheels on rough terrain or flat surface. The performance of legged machines is greater than wheeled or tracked walking machines on an unstructured terrain. These types of machines are used for data collections in a variety of areas such as large agricultural sec...
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Context 1
... follower crank will always have the same angular velocity. The dimensional synthesis of the change point four-bar evaluates the perfect structure that can provide the maximum workspace. The dimensional synthesis is carried out by controlling the following geometrical parameters such as the link length, and the angle between the link as given in Fig. 5. The typical structures with the dimensions are drawn and, the angle and the displacements are identified. The relations between the linkage elements for the four-bar synthesis in Fig. 5(a) are given in Eqs. (1) One or more data of the frequency of oscillation, the speed at different positions and range of motion of the slider may be ...
Context 2
... The dimensional synthesis is carried out by controlling the following geometrical parameters such as the link length, and the angle between the link as given in Fig. 5. The typical structures with the dimensions are drawn and, the angle and the displacements are identified. The relations between the linkage elements for the four-bar synthesis in Fig. 5(a) are given in Eqs. (1) One or more data of the frequency of oscillation, the speed at different positions and range of motion of the slider may be provided. Then, the required task will be finding the dimensions of the members of the leg mechanism and position of the slider such as to have the desired motion of the leg mechanism. The ...
Context 3
... the speed at different positions and range of motion of the slider may be provided. Then, the required task will be finding the dimensions of the members of the leg mechanism and position of the slider such as to have the desired motion of the leg mechanism. The relation between the link lengths of the crank mechanism are determined from Fig. 5(b) parametrically to formulate the general equation of its dimensions as given in Eqs. (4) to (7). ...
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Citations
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.
Four-bar mechanisms are widespread in industrial and quotidian applications, but their design requires deep knowledge and experience in Mechanisms and Machine Theory. In this area, path synthesis is a common problem. It consists in calculating the length of the bars defining a mechanism so that a particular point of its structure follows the desired trajectory. This paper presents SALAR Mechanism Synthesizer, a new open-source software package that aims to be an easy-to-use yet powerful tool for addressing this kind of problem. This tool offers four different optimizers from the literature, one of them specially designed for mechanism synthesis. It also includes a new method for expressing and comparing paths, and hence, to define the optimization criterion. This method, referred to as normalized shape-descriptor vector(s) (NSDV(s)) and presented in this paper, allows us to handle paths without being affected by translation, rotation, and scale changes. The software package has been used for addressing six well-known problems from the literature. According to the results achieved, it arises as a valuable tool in terms of accuracy, convenience, and availability.
