Design of a compact statically balanced direct-drive manipulator

Robotica ◽  
1990 ◽  
Vol 8 (4) ◽  
pp. 347-353
Author(s):  
Tarek M. Abdel-Rahman ◽  
M.A. Elbestawi

SUMMARYThis paper addresses the conceptual design of direct-drive manipulators which have good promise for high speed, high precision manipulation. In the design methodology presented, the procedure begins by considering the kinematic aspects and ends by configuring manipulator structures with promising kinematic and dynamic characteristics. Based on the conceptual design considerations, a novel 3 DOF (RRR) direct-drive manipulator is proposed and analyzed. The manipulator structure has only five links and a compact configuration. Manipulator kinematics and dynamics are analyzed. Design guidelines are derived for static balancing of the manipulator and for minimizing the inertias driven by the motors. Operational configurations that either improve or worsen the kinematic and dynamic behaviour or characteristics of the manipulator are identified. The proposed design has an advantage over many currently known direct-drive manipulators for achieving two desirable mechanical features, namely: static balancing and compactness (smaller driven inertias).

2012 ◽  
Vol 151 ◽  
pp. 463-468 ◽  
Author(s):  
Jun Feng Wang ◽  
Xian Feng Du ◽  
Qing Ming Hu ◽  
Shi Gang Wang

With the rapid development of science and technology, Lathe will be sure to develop in the direction of high speed, high precision and high stability as the most basic and important production equipment in industry. The spindle is the one of important component in the lathe, of which static and dynamic characteristics is directly related to the machining precision and machining stability, and the performance of spindle system directly affects the overall machine specifications. Through the analysis of the characteristics of spindle, the ways and means of the spindle analysis are studied. For the requirements of static and dynamic characteristics analysis in the process of spindle design on high-precise CNC lathes hydrostatic, direct-drive spindle motor mode is used. Three-supporting structure is adapted in the layout of spindle bearing in order to improve the accuracy and stability of the spindle drive. The rolling bearing is used in auxiliary support, the front and rear radial bearing is used in master hydrostatic bearing. Thrust bearings are located on both sides of the former type of radial bearing to complete the selection of the spindle material and the design of the structural primary dimensions. It is meaningful to improve the specifications of CNC lathes, guide the design, generation and modification of the high precise CNC lathe and enhance static dynamic characteristics of the spindle and improve accuracy and stability of the machine tool processing.


2020 ◽  
Vol 1 ◽  
pp. 857-866
Author(s):  
G. Formentini ◽  
C. Favi ◽  
F. Bouissiere ◽  
C. Cuiller ◽  
P.-E. Dereux ◽  
...  

AbstractThe work aims at the definition of a design methodology able to drive designers in the definition of product architectures, starting from rough information available at the conceptual design. The methodology identifies design guidelines useful for the development of product architectures optimized for a given target (i.e. assembly, cost). The methodology is based on domains which combine attributes related to a specific aspect of the target. The exploratory application of the methodology was performed to address the equipment installation of a civil aircraft for assembly/installation target.


Author(s):  
Jonathan Vlastuin ◽  
Clément Dejeu ◽  
Anthony Louet ◽  
Jérôme Talbotec ◽  
Ingrid Lepot ◽  
...  

For several years, Safran has been involved in the design and optimization of contra rotating open rotors. This innovative architecture is known for allowing drastic reduction in fuel burn, but its development is facing complex technological challenges such as acoustics, aerodynamics, and weight penalty due to the mechanical complexity of an Open Rotor. Since 2010, Safran has been developing the experimental test bench HERA (1/5 mock-up scale) to improve the understanding of the complex aerodynamics and acoustics phenomena involved in the counter rotating propellers configuration. Isolated and installed low speed and high speed wind tunnel campaigns, including PIV measurements have been extremely helpful in defining design guidelines for full scale open rotor specification. These tests have been used as CFD feed-back among other purposes. An iterative process involving CFD optimization (in close collaboration with Cenaero) and wind tunnel test campaigns has been developed over the last 4 years and has led to the definition of an innovative design strategy, which has been successfully tested during the process of the full scale counter rotating propellers design for the SAGE2 ground test demonstrator engine. This phase has evidenced the absolute necessity of a multi-disciplinary design method when it comes to full scale and “rig-ready” design. Ensuring high propulsive efficiency and at the same time, minimizing the acoustic level, while maintaining severe mechanical constraints such as weight, inertia and proper dynamic positioning under control, requires a dedicated and integrated “all inclusive” design process. The aim of this paper is to present the design methodology and some of the wind tunnel tests results carried out over the last 4 years, which have led to the definition of a novel multidisciplinary design methodology that involves CFD, FEM and acoustics.


Author(s):  
F Wang ◽  
X Zhao ◽  
D Zhang ◽  
Z Ma ◽  
X Jing

To provide faster, more repeatable, and stronger microelectronics bonding technology, this article presents the design and implementation of a robust and precision controller for a high-speed linear voice-coil motor, direct-drive, XY positioning table. Moreover, the dynamic design methodology of the control system for the positioning table is proposed based on electromechanical co-simulation. Using the finite-element method and dynamic analysis, the rigid–flexible coupled mechanical model of the XY table is established. With the aid of the system identification approach, the open-loop model of the control system for the X-axis table is obtained. On this basis, the proportion integration differentiation controller with incomplete derivation and the sliding mode controller (SMC) with the exponential reaching law are designed to control the X-axis table. The performances of the controllers are investigated using electromechanical co-simulations and experimental tests, and the results show that the motion overshoot and settling time are reduced using the SMC with an exponential reaching law. The SMC with the exponential reaching law also shows strong robustness against external disturbances. The experiment and co-simulation results are in good agreement, which confirms the validity and feasibility of the dynamic design methodology for a high-speed and high-accuracy positioning table based on electromechanical co-simulation.


2015 ◽  
Vol 1 (1) ◽  
pp. 5-16
Author(s):  
John Ohoiwutun

Utilization of conventional energy sources such as coal, fuel oil, natural gas and others on the one hand has a low operating cost, but on the other side of the barriers is the greater source of diminishing returns and, more importantly, the emergence of environmental pollution problems dangerous to human life. This study aims to formulate the kinematics and dynamics to determine the movement of Solar Power Mower. In this study, using solar power as an energy source to charge the battery which then runs the robot. Design and research was conducted in the Department of Mechanical Workshop Faculty of Engineering, University of Hasanuddin of Gowa. Control system used is a manual system using radio wave transmitter and receiver which in turn drive the robot in the direction intended. Experimental results showed that treatment with three variations of the speed of 6.63 m / s, 8.84 m / s and 15.89 m / sec then obtained the best results occur in grass cutting 15.89 sec and high-speed cutting grass 5 cm. Formulation of kinematics and dynamics for lawn mowers, there are 2 control input variables, x and y ̇ ̇ 3 to control the output variables x, y and θ so that there is one variable redudant. Keywords: mobile robots, lawn mower, solar power


Author(s):  
Xiangying Hou ◽  
Yuzhe Zhang ◽  
Hong Zhang ◽  
Jian Zhang ◽  
Zhengminqing Li ◽  
...  

The vector form intrinsic finite element (VFIFE) method is springing up as a new numerical method in strong non-linear structural analysis for its good convergence, but has been constricted in static or transient analysis. To overwhelm its disadvantages, a new damping model was proposed: the value of damping force is proportional to relative velocity instead of absolute velocity, which could avoid inaccuracy in high-speed dynamic analysis. The accuracy and efficiency of the proposed method proved under low speed; dynamic characteristics and vibration rules have been verified under high speed. Simulation results showed that the modified VFIFE method could obtain numerical solutions with good efficiency and accuracy. Based on this modified method, high-speed vibration rules of spiral bevel gear pair under different loads have been concluded. The proposed method also provides a new way to solve high-speed rotor system dynamic problems.


1989 ◽  
Vol 27 (3) ◽  
pp. 375-394 ◽  
Author(s):  
K. YOUCEF-TOUMI ◽  
A. T. Y. KUO
Keyword(s):  

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