Modeling and Mechanical Design of an Active-Caster Omnidirectional Mechanism with a Ball Transmission

2018 ◽  
Vol 30 (6) ◽  
pp. 910-919 ◽  
Author(s):  
Kosuke Kato ◽  
◽  
Masayoshi Wada
Keyword(s):  
Power Distribution ◽  
Control Function ◽  
Mechanical Design ◽  
Computer Control ◽  
Single Layer ◽  
Control Algorithms ◽  
Angle Sensor ◽  
Simple Motor ◽  
Point Control ◽  
Point To Point

This paper presents kinematic and static analyses of an active-caster robotic drive with a single-layer ball transmission (ACROBAT-S). On the basis of the analyses, a single-wheel prototype is designed, and fundamental experiments using the prototype are conducted. The proposed ACROBAT-S includes a ball transmission that transmits power to a wheel axis and steering axis of an active-caster wheel in an appropriate ratio to produce so-called “caster motion.” The power distribution is realized mechanically rather than by complicated computer control algorithms. Therefore, the angle sensor for detecting the wheel orientation, and the control calculations for coordinated control of the wheel and steering motors of a conventional system are eliminated. Thus, the proposed mechanical design, which transfers a part of the control function to the mechanism, contributes to simplifying the overall control system. The results of the analyses and experiments with a prototype confirm that the proposed active-caster mechanism, ACROBAT-S, can realize the expected omnidirectional motion with simple motor control, such as Point-To-Point control.

The new CM-Series TEMs: integration of a five-axis motorized, fully computer-controlled goniometer

1993 ◽  
Vol 51 ◽  
pp. 258-259
Author(s):  
Marc J.C. de Jong ◽  
P. Emile S.J. Asselbergs ◽  
Max T. Otten
Keyword(s):  
Mechanical Design ◽  
Computer Control ◽  
Objective Lens ◽  
Access Port ◽  
Vibration Stability ◽  
Transmission Electron ◽  
Computer Controlled ◽  
High Degree ◽  
Five Axis ◽  
Five Axes

A new step forward in Transmission Electron Microscopy has been made with the introduction of the CompuStage on the CM-series TEMs: CM120, CM200, CM200 FEG and CM300. This new goniometer has motorization on five axes (X, Y, Z, α, β), all under full computer control by a dedicated microprocessor that is in communication with the main CM processor. Positions on all five axes are read out directly - not via a system counting motor revolutions - thereby providing a high degree of accuracy. The CompuStage enters the octagonal block around the specimen through a single port, allowing the specimen stage to float freely in the vacuum between the objective-lens pole pieces, thereby improving vibration stability and freeing up one access port. Improvements in the mechanical design ensure higher stability with regard to vibration and drift. During stage movement the holder O-ring no longer slides, providing higher drift stability and positioning accuracy as well as better vacuum.

Model-based HSF using by target point control function

2015 ◽  
Author(s):  
Seongjin Kim ◽  
Munhoe Do ◽  
Yongbae An ◽  
Jaeseung Choi ◽  
Hyunjo Yang ◽  
...  
Keyword(s):  
Control Function ◽  
Target Point ◽  
Model Based ◽  
Point Control

Design with Nonhomogeneous Materials—Part I: Pure Bending of Prismatic Bars

1987 ◽  
Vol 109 (1) ◽  
pp. 82-86 ◽  
Author(s):  
V. K. Stokes
Keyword(s):  
Tensile Test ◽  
Material Properties ◽  
Elastic Moduli ◽  
Mechanical Response ◽  
Mechanical Design ◽  
Beam Theory ◽  
Pure Bending ◽  
Strongly Coupled ◽  
Point To Point ◽  
Nonhomogeneous Materials

Because material properties vary from point to point in nonhomogeneous materials, there is some question as to what “properties” are measured in tests such as the tensile test, and how such “properties” can be used in the mechanical design process. In this paper, the mechanical response of nonhomogeneous prismatic bars in pure bending has been shown to depend on parameters that are strongly coupled combinations of geometry and material properties. The purely geometry based inertia tensor in homogeneous beam theory is replaced in the nonhomogeneous case by the rigidity tensor, which combines geometry and material properties. Interpretations for the average elastic moduli, which would be determined by tests on nonhomogeneous materials, have been explored. Also discussed is the usefulness of such average moduli for predicting the mechanical response of nonhomogeneous bars.

scholarly journals An approach to point-to-point control for direct-drive SCARA-type robots.

1991 ◽  
Vol 111 (1) ◽  
pp. 63-69
Author(s):  
Satoshi Ogasawara ◽  
Tomoyuki Joichi ◽  
Hirofumi Akagi
Keyword(s):  
Direct Drive ◽  
Point Control ◽  
Point To Point

scholarly journals Mechatronic Control System for a Compliant and Precise Pneumatic Rotary Drive Unit

Actuators ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Johannes T. Stoll ◽  
Kevin Schanz ◽  
Andreas Pott
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Mechanical Design ◽  
Control Algorithms ◽  
Field Oriented Control ◽  
Pneumatic Drive ◽  
Drive Unit ◽  
Control Approach ◽  
Human Robot Collaboration ◽  
Rotary Drive

Robots that enable safe human-robot collaboration can be realized by using compliant drive units. In previous works, different mechanical designs of compliant pneumatic rotary drive units with similar characteristics have been presented. In this paper, we present the overall control approach that we use to operate one of these compliant pneumatic rotary drive units. We explain the mechanical design and derive the differential equation that describes the dynamics of the system. In order to successfully operate a pneumatic drive unit with three or more working chambers, the torque specified by the controller has to be split up onto the working chambers. We transfer the well-known field-oriented control approach from electric motors to the investigated pneumatic drive unit to create such a torque mapping. Moreover, we develop optimized torque mappings that are tailored to work with this type of drive unit. Furthermore, we introduce and compare two control algorithms based on different implementations of state feedback to realize position control. Finally, we present the step responses that we achieve when we implement either one of the control algorithms in combination with the different torque mappings.

How to achieve precise operation of a robotic manipulator on a macro to micro/nano scale

2017 ◽  
Vol 37 (2) ◽  
pp. 186-199 ◽  
Author(s):  
Zhiqiang Yu ◽  
Qing Shi ◽  
Huaping Wang ◽  
Ning Yu ◽  
Qiang Huang ◽  
...  
Keyword(s):  
Control Algorithm ◽  
Mechanical Design ◽  
Robotic Manipulator ◽  
Control Algorithms ◽  
General Control ◽  
Content Type ◽  
Mechanical Parts ◽  
Accurate Perception ◽  
And Control ◽  
Made In

Purpose The purpose of this paper is to present state-of-the-art approaches for precise operation of a robotic manipulator on a macro- to micro/nanoscale. Design/methodology/approach This paper first briefly discussed fundamental issues associated with precise operation of a robotic manipulator on a macro- to micro/nanoscale. Second, this paper described and compared the characteristics of basic components (i.e. mechanical parts, actuators, sensors and control algorithm) of the robotic manipulator. Specifically, commonly used mechanisms of the manipulator were classified and analyzed. In addition, intuitive meaning and applications of its actuator explained and compared in details. Moreover, related research studies on general control algorithm and visual control that are used in a robotic manipulator to achieve precise operation have also been discussed. Findings Remarkable achievements in dexterous mechanical design, excellent actuators, accurate perception, optimized control algorithms, etc., have been made in precise operations of a robotic manipulator. Precise operation is critical for dealing with objects which need to be manufactured, modified and assembled. The operational accuracy is directly affected by the performance of mechanical design, actuators, sensors and control algorithms. Therefore, this paper provides a categorization showing the fundamental concepts and applications of these characteristics. Originality/value This paper presents a categorization of the mechanical design, actuators, sensors and control algorithms of robotic manipulators in the macro- to micro/nanofield for precise operation.

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