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There are several ubiquitous kinematic structures that are used in industrial robots, with the most prominent being a six-axis angular structure. However, researchers are experimenting with task-based mechanism synthesis that could provide higher efficiency with custom optimized manipulators. Many studies have focused on finding the most efficient...
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... end-effector is connected to the last link or joint. An example of a manipulator built by the algorithm is shown in Figure 1. ...
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... this case, the orientation changes in one axis along the whole trajectory. Task 3 ( Figure 10) was created to provide the manipulators with a difficult trajectory. It is formed by connecting several curves together. ...
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... stochastic nature of the genetic algorithms can be seen in Figure 11. The algorithm almost never finds the same configuration. ...
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... test this hypothesis, we selected task 2 and increased the number of generations from 100 to 1000. Figure 15 shows the results of this test. As is visible from Figure 15, even a 10x increase in generations did not produce manipulators with cost values low enough to be comparable to our previous test. ...
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... test this hypothesis, we selected task 2 and increased the number of generations from 100 to 1000. Figure 15 shows the results of this test. As is visible from Figure 15, even a 10x increase in generations did not produce manipulators with cost values low enough to be comparable to our previous test. One run of the algorithm with 1000 generations takes about 22 h, which makes any practical use difficult. ...
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... inspect how significantly different each link type performs during the different tasks, we performed a one-way ANOVA analysis on the results of each GA run. Figure 16 shows mean estimates and comparison intervals at a significance level of 0.05. In the graphs, if the lines overlap vertically, the link types did not perform with significant difference. ...
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The primary objective of this study was to optimize the trajectory planning and positioning error of a five-degree-of-freedom robotic manipulator. First, a multigroup ant colony optimization (MACO) algorithm was used to determine the shortest trajectory with obstacle avoidance. A quantum-behaved particle swarm optimization (QPSO) algorithm was subs...
Citations
... For this reason, procedures are sought with the help of which it would be possible to design an optimized kinematic structure of the robotic arm. For example, articles , Kot 2021, Pastor 2021] are devoted to this issue, describing design procedures using various optimization algorithms. The output of these procedures is usually a simplified kinematic structure of the robotic arm, with optimized dimensions of individual links of the whole mechanism. ...
Robotic arms are complex mechatronic systems. Therefore, their design requires knowledge and experience from various technical fields, such as mechanics, electrical engineering, electronics or control. From the view of the requirements placed on developers, the design of robotic arms is one of the more complex tasks. Unfortunately, there is a lack of necessary specialists in this field of technology. Therefore, ways are sought to help existing specialists in their work and, simultaneously, reduce the time needed to design the required equipment. At the same time, there are also sought ways to open the way to this issue for developers who do not yet have enough experience. For this reason, algorithms and development tools have been developed to significantly simplify and reduce the time required to design robotic arms and simultaneously automate as much of this process as possible. The aim is to shorten the design time and achieve better results than in the case of designs according to classical procedures.
... The design of spatial links are presented in Ref. [36] with respect to the kinematic requirements such as motion smoothness, obstacle avoidance, and force transmission. Recently, the utilization of curved links to avoid the obstacles in a static environment is shown in Ref. [37], and a comparative study involving four types of links has been presented for the design of an optimal configuration is shown in Ref. [38]. However, in these recent works, the major challenges that lie in this area are listed: ...
... With this, the results show that optimizing the shape of the link from straight to the curved links, using the presented methodology, leads to the reduced torque for the given paths to be followed by the given modular configuration. The unconventional and the curved links presented in the literature [13,37,38] have focused on the kinematic aspects of the manipulators. Through this article, a methodology of approximating the rigid curved links is presented, which can be used to generate the unconventional configuration for desired customized design and to use lesser joint torque values. ...
Customization of manipulators having unconventional parameters and link shapes have gained attention to accomplish non-repetitive tasks in a given cluttered environment. Adaptive modular and reconfigurable designs are being used to achieve customization, and have provided time and cost-effective solutions. Major challenges are associated to provide the systematic approach on the design and realization of modular components considering connectivity and integration with each other. This paper focuses on the architectural synthesis of modular links, optimized with respect to the dynamic torques while following a prescribed set of trajectories. The design methodology is proposed as an Architecture Prominent Sectioning-k strategy which assumes a modular link as equivalent system of k number of point masses, performing optimization to minimize the joint torques and map the resulting re-adjusted point masses into a possible architecture. The proposed strategy is general and can be applied to planar or spatial manipulators with n-DoF even with non-parallel and non-perpendicular jointed configurations. The design of optimal curved links is realized resulting from the optimized solution considering the dynamics of the modular configurations over primitive trajectories. The proposed modular library of unconventional curved link modules with joint modules have shown lesser requirement of the joint torques compared to the conventional straight links.
... Among global optimization algorithms, in the case of synthesis of a robot manipulator, Genetic Algorithms (GA) have been applied in various studies. The comparison of straight, rounded, and curved links was studied by Pastor et al. [16], using Schunk actuator modules as joints. The design parameters vary depending on the type of link, without directly specifying any kinematic representation. ...
... A method that uses the dual-quaternion representation was presented in [15]. RPYXYZ values were applied in [16], [20]- [22]. In addition to that, we added a method that does not apply the norm of the transformation matrix but its elements, a method that uses the norm of the dual quaternions, and we also applied a new method given as a metric in a 12-dimensional Euclidean space E 12 . ...
... If there are no limits for the initial estimations, there will be a substantial number of possible solutions for a single task. This can serve as an initial population for genetic algorithms [16] or as a data set for the synthesis using neural networks [26]. Other benefits of the presented method are as follows. ...
This paper presents a set of algorithms for the synthesis of kinematic structures of serial manipulators using multiple constraint formulation and provides a performance comparison of different kinematic representations, the Denavit-Hartenberg notation, the Product of Exponentials (screws), and Roll-Pitch-Yaw angles with translation parameters. Synthesis is performed for five given tasks, and both revolute and prismatic joints can be synthesized. Two different non-linear programming optimization algorithms were used to support the findings. The results are compared and discussed. Data show that the choice of the constraint design method has a significant impact on the success rate of optimization convergence. The choice of representation has a lower impact on convergence, but there are differences in the optimization time and the length of the designed manipulators. Furthermore, the best results are obtained when multiple methodologies are used in combination. An arbitrary manipulator was designed and assembled based on a trajectory in the collision environment to demonstrate the advantages of the proposed methodology. The input/output data and synthesis methodology algorithms are provided through an open repository.
... Furthermore, GA can be used to build a manipulator from adaptive modules to perform a desired task [11]. Pastor et al. [12] compared straight, rounded, and curved mechanism links synthesised using GA. Valsamos et al. created so-called pseudo-joints (links which can be modified) and proposed a GA that tries to find the kinematic structure with the best manipulability [13]. ...
Researchers often deal with the synthesis of the kinematic structure of a robotic manipulator to determine the optimal manipulator for a given task. This approach can lower the cost of the manipulator and allow it to achieve poses that might be unreachable by universal manipulators in an existing constrained environment. Numerical methods are broadly used to find the optimum design but they often require an estimated initial kinematic structure as input, especially if local-optimum-search algorithms are used. This paper presents four different algorithms for such an estimation using the standard Denavit–Hartenberg convention. Two of the algorithms are able to reach a given position and the other two can reach both position and orientation using Bézier splines approximation and vector algebra. The results are demonstrated with three chosen example poses and are evaluated by measuring manipulability and the total link length of the final kinematic structures.
... One open challenge is to automatically design the modules by evolution in order to find an optimal set of modules. In this line, preliminary works to assess different module designs have been carried out Moreno and Faina, 2020b;Pastor et al., 2021). ...
In order to explain the synthesis process of the serial mechanism in a concise and intuitive geometric perspective, this paper introduces conformal geometric algebra, an effective geometric representation and computational mathematical tool, to describe the actuator poses and joint axes. The actuator pose is represented as three characteristic planes, and the three planes are sequentially overlapped with the corresponding planes of the desired pose to realize the pose transformation requirement. In the process of plane coincidence transformation, the outer product operation of conformal geometric algebra is used to construct the joint axes of the mechanism, and this process can visualize the whole process of mechanism design. Then, the influence of the revolute joint position on the actuator transformation is analyzed, and the rational layout of the revolute joints is used to satisfy the displacement demand of the mechanism instead of the prismatic joints, so as to achieve the mechanism's fewer degrees of freedom optimized design. Finally, the 2R1T and 2R mechanisms are designed according to the set demand of any two poses, and the correctness of the proposed method is verified by using the prototype experiment.
The increasing utilization of artificial intelligence and robots in various
services in healthcare makes robots as preferred intelligent agent model.
Robotic evolution produces the optimal robotic innovation in the robotic
system or its subsystems, morphology, kinematics, and control. An intelligent
algorithm is programmed into the control of the robotic manipulator. This
paper aims to identify the control of artificial intelligence and identify
comparisons of artificial intelligence algorithms control for healthcare robotic
manipulators. This study uses a systematic literature review using the
Preferred Reporting Items for Systematic Review (PRISMA). The potential
for further articles is explored related to the theme of the research carried out.
The conclusion obtained many studies have been carried out to optimize the
work and tasks of the robotic arm manipulator, specifically developing various
types of manipulator control (algorithms) combined with neural networks to
get the right and appropriate algorithm.
