error_outline You can access the new MDPI.com website here. Explore and share your feedback with us.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (6)

Search Parameters:
Keywords = 3-UPU parallel manipulator

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
20 pages, 2158 KB  
Article
Kinematic Analysis and Workspace Evaluation of a New Five-Axis 3D Printer Based on Hybrid Technologies
by Azamat Mustafa, Rustem Kaiyrov, Yerik Nugman, Mukhagali Sagyntay, Nurtay Albanbay, Algazy Zhauyt, Zharkynbek Turgunov, Ilyas Dyussebayev and Yang Lei
Robotics 2026, 15(1), 16; https://doi.org/10.3390/robotics15010016 - 7 Jan 2026
Abstract
Additive manufacturing technologies for metals are developing rapidly. Among them, wire arc additive manufacturing (WAAM) has become widespread due to its accessibility. However, parts produced using WAAM require surface post-processing; therefore, hybrid technologies have emerged that combine additive and subtractive processes within a [...] Read more.
Additive manufacturing technologies for metals are developing rapidly. Among them, wire arc additive manufacturing (WAAM) has become widespread due to its accessibility. However, parts produced using WAAM require surface post-processing; therefore, hybrid technologies have emerged that combine additive and subtractive processes within a single compact manufacturing complex. Such systems make it possible to organize single-piece and small-batch production, including for the repair and restoration of equipment in remote areas. For this purpose, hybrid equipment must be lightweight, compact for transportation, provide sufficient workspace, and be capable of folding for transport. This paper proposes the concept of a multifunctional metal 3D printer based on hybrid technology, where WAAM is used for printing, and mechanical post-processing is applied to obtain finished parts. To ensure both rigidity and low mass, a 3-UPU parallel manipulator and a worktable with two rotational degrees of freedom are employed, enabling five-axis printing and machining. The printer housing is foldable for convenient transportation. The kinematics of the proposed 3D printer are investigated as an integrated system. Forward and inverse kinematics problems are solved, the velocities and accelerations of the moving platform center are calculated, singular configurations are analyzed, and the workspace of the printer is determined. Full article
(This article belongs to the Section Industrial Robots and Automation)
Show Figures

Graphical abstract

27 pages, 4375 KB  
Article
Dynamic Modeling and Performance Analysis of a Novel Dual-Platform Biped Robot Based on a 4-UPU Parallel Mechanism
by Zhaofeng Shi, Shengtao Song, Ruiqin Li, Fengping Ning, Lei Zhang and Lianzheng Deng
Machines 2025, 13(12), 1094; https://doi.org/10.3390/machines13121094 - 26 Nov 2025
Viewed by 317
Abstract
Biped robots based on parallel mechanisms hold great potential for applications in complex terrains. Based on a 4-UPU parallel mechanism, this paper proposes a novel biped robot that achieves alternating bipedal locomotion and turning with only six actuators by employing fixed/moving platform switching [...] Read more.
Biped robots based on parallel mechanisms hold great potential for applications in complex terrains. Based on a 4-UPU parallel mechanism, this paper proposes a novel biped robot that achieves alternating bipedal locomotion and turning with only six actuators by employing fixed/moving platform switching and following an “upper platform + lower foot” continuous gait strategy. Using the influence coefficient method, the first order and second order kinematic influence coefficient matrices of the biped robot were derived. Based on the principle of virtual work, a dynamic model of the robot was formulated, and its validity was verified through numerical simulations. The dynamic performance of the robot was further evaluated using the Dynamic Manipulability Ellipsoid (DME) index, while its stability during step-climbing and turning was analyzed using the Zero-Moment Point (ZMP) method. The results demonstrate that the dual-platform biped robot features a rational structure and exhibits robust stability during step-climbing and turning. Full article
(This article belongs to the Special Issue The Kinematics and Dynamics of Mechanisms and Robots)
Show Figures

Figure 1

16 pages, 4261 KB  
Article
Research on the Conditions and Optimization of 3-UPU Parallel Manipulators That Naturally Realize Three Translational Degrees of Freedom
by Bo Hu and Peng Bai
Machines 2025, 13(4), 265; https://doi.org/10.3390/machines13040265 - 24 Mar 2025
Cited by 2 | Viewed by 970
Abstract
The characteristics of the degrees of freedom (DOFs) of the 3-UPU parallel mechanisms (PMs) are closely related to the orientations of the ending R joints fixed connected with the platforms. The orientations of the ending revolute (R) joints in the Tsai 3-UPU PM [...] Read more.
The characteristics of the degrees of freedom (DOFs) of the 3-UPU parallel mechanisms (PMs) are closely related to the orientations of the ending R joints fixed connected with the platforms. The orientations of the ending revolute (R) joints in the Tsai 3-UPU PM cannot naturally realize three translational DOFs. First, this paper gives and proves the geometric conditions of the ending R joint fixed to the platforms that can naturally ensure three translational DOFs of the 3-UPU PMs. Second, based on the common motion/force index and good transmission workspace volume of the 3-UPU translational PMs, the performance map of the PMs is drawn, and the corresponding optimization design area of the PMs is obtained. Finally, combined with the obtained optimization design area, in view of the differences in the constraint and stiffness performance of the 3-UPU translational PMs, the multi-objective optimization is carried out using the game theory algorithm, and the orientations of the ending R joints for the 3-UPU translational PMs with good constraint and stiffness performance are obtained. Full article
(This article belongs to the Section Machine Design and Theory)
Show Figures

Figure 1

15 pages, 3314 KB  
Article
Screw Dynamics of a Multibody System by a Schoenflies Manipulator
by Jing-Shan Zhao, Han-Lin Sun, Hao-Yang Li and Dong-Jie Zhao
Appl. Sci. 2023, 13(17), 9732; https://doi.org/10.3390/app13179732 - 28 Aug 2023
Cited by 8 | Viewed by 2434
Abstract
This paper presents a screw dynamics method for multi-rigid-body systems. It establishes the relationship between velocity screw (twist) and force screw (wrench) in the theorem of momentum screw. Then, the structure of a 2UPS + 2UPU parallel manipulator is introduced as an example [...] Read more.
This paper presents a screw dynamics method for multi-rigid-body systems. It establishes the relationship between velocity screw (twist) and force screw (wrench) in the theorem of momentum screw. Then, the structure of a 2UPS + 2UPU parallel manipulator is introduced as an example of application. By analyzing the constraint wrench of each limb and the twist of the moving platform in the theorem of momentum screw, the dynamics equation for solving the driving force makes the method very convenient for computer programming. The dynamics equation can be reorganized into a non-homogeneous linear equation and establishes the relationship between the constraint wrench of each limb and the twist of the moving platform in screw coordinate. The outstanding advantage of the algorithm proposed in this paper is that the average calculation time is only 83.21% of that of the Newton–Euler method for the 2UPS + 2UPU parallel manipulator on the same computer. This methodology provides a convenient canonical form for the dynamics analysis of multi-rigid-body systems. Full article
Show Figures

Figure 1

14 pages, 1707 KB  
Review
A Review of the Literature on the Lower-Mobility Parallel Manipulators of 3-UPU or 3-URU Type
by Raffaele Di Gregorio
Robotics 2020, 9(1), 5; https://doi.org/10.3390/robotics9010005 - 13 Jan 2020
Cited by 26 | Viewed by 7582
Abstract
Various 3-UPU architectures feature two rigid bodies connected to one another through three kinematic chains (limbs) of universal–prismatic–universal (UPU) type. They were first proposed in the last decade of the 20th century and have animated discussions among researchers for more-or-less two decades. Such [...] Read more.
Various 3-UPU architectures feature two rigid bodies connected to one another through three kinematic chains (limbs) of universal–prismatic–universal (UPU) type. They were first proposed in the last decade of the 20th century and have animated discussions among researchers for more-or-less two decades. Such discussions brought to light many features of lower-mobility parallel manipulators (PMs) that were unknown until then. The discussions also showed that such architectures may be sized into translational PMs, parallel wrists, or even reconfigurable (metamorphic) PMs. Even though commercial robots with these architectures have not yet been built, the interest in them remains. Consequently, a review of the literature on these architectures, highlighting their contribution to the progress of lower-mobility PM design, is still of interest for the scientific community. This paper aims at presenting a critical review of the results that have been obtained up until now. Full article
(This article belongs to the Special Issue Kinematics and Robot Design II, KaRD2019)
Show Figures

Figure 1

9 pages, 1095 KB  
Article
Reconfiguration Analysis of a 3-DOF Parallel Mechanism
by Maurizio Ruggiu and Xianwen Kong
Robotics 2019, 8(3), 66; https://doi.org/10.3390/robotics8030066 - 2 Aug 2019
Cited by 4 | Viewed by 8000
Abstract
This paper deals with the reconfiguration analysis of a 3-DOF (degrees-of-freedom) parallel manipulator (PM) which belongs to the cylindrical parallel mechanisms family. The PM is composed of a base and a moving platform shaped as equilateral triangles connected by three serial kinematic chains [...] Read more.
This paper deals with the reconfiguration analysis of a 3-DOF (degrees-of-freedom) parallel manipulator (PM) which belongs to the cylindrical parallel mechanisms family. The PM is composed of a base and a moving platform shaped as equilateral triangles connected by three serial kinematic chains (legs). Two legs are composed of two universal (U) joints connected by a prismatic (P) joint. The third leg is composed of a revolute (R) joint connected to the base, a prismatic joint and universal joint in sequence. A set of constraint equations of the 1-RPU−2-UPU PM is derived and solved in terms of the Euler parameter quaternion (a.k.a. Euler-Rodrigues quaternion) representing the orientation of the moving platform and of the Cartesian coordinates of the reference point on the moving platform. It is found that the PM may undergo either the 3-DOF PPR or the 3-DOF planar operation mode only when the base and the moving platform are identical. The transition configuration between the operation modes is also identified. Full article
(This article belongs to the Special Issue Kinematics and Robot Design II, KaRD2019)
Show Figures

Figure 1

Back to TopTop