Design of the Wearable Spatial Gravity Balance Mechanism

2021 ◽  
pp. 1-19
Author(s):  
Yijia Peng ◽  
Wanghui Bu ◽  
Jing Chen
Keyword(s):  
Design Method ◽  
Gravity Compensation ◽  
Passive Components ◽  
Gravity Compensator ◽  
Compensation Mechanisms ◽  
Strict Condition ◽  
Timing Belt ◽  
Motion Features ◽  
Save Energy ◽  
Balance Mechanism

Abstract Gravity compensation mechanisms are widely used in manipulators and exoskeletons as passive components which generate counter-gravity force and save energy. While there have been making great progresses in the design of the planar gravity compensator and its spatial counterpart, a strict condition that the axes of the gravity compensators are aligned with the axes of the links being balanced (LBBs) exactly is usually assumed implicitly. In this paper, the design method of the wearable spatial gravity compensator compatible to the misalignment and drift of the rotation center of the LBB is carefully studied. First, the design of the planar gravity compensation unit (PGCU) is presented, and then it is adapted into the spatial gravity compensation unit (SGCU) by the motion features of the fixed-point rotation. Then, the type synthesis of the SGCU is conducted followed by the analyses of the acting patterns of synthesized SGCUs on the LBBs and gravity compensation performances when the misalignments and drifts of rotation centers of the LBBs occur. Finally, the SGCUs can be combined with timing belt mechanisms (TBMs) to construct gravity compensation mechanisms for spatial serial linkages. Simulations of the exoskeleton constructed by SGCUs are conducted to verify the performance of gravity balance and the effectiveness of the proposed design method.

Static balancer for the neck of a face robot

2013 ◽  
Vol 228 (3) ◽  
pp. 561-568 ◽  
Author(s):  
Changhyun Cho ◽  
Seungjong Kim
Keyword(s):  
Degree Of Freedom ◽  
Experimental Results ◽  
The Other ◽  
Gravity Compensation ◽  
Gravity Compensator ◽  
Face Robot ◽  
The Face ◽  
Static Balancer ◽  
Compact Design

We propose a 3-degree of freedom gravity compensator for the neck of a robotic face. The neck of the face robot is configured with yaw-pitch-pitch-roll rotations. Since the yaw rotation is made parallel to gravity, only the pitch-pitch-roll rotations are considered for gravity compensation. The 1-degree of freedom gravity compensator is located at the first pitch joint. A 2-degree of freedom gravity compensator equivalent to the existing gravity compensator is proposed and applied to the second pitch and roll rotations. A parallelogram is adopted between the first and second pitch rotations. One end of the 2-degree of freedom gravity compensator is attached at the parallelogram and the other is fixed at the face. Wires are used to realize a zero-length spring for all gravity compensators and all springs are located at the base for compact design. Experimental results for gravity compensation show that gravitational torques were effectively counterbalanced by the proposed 3-degree of freedom gravity compensator.

scholarly journals Design Method for an Auto-Balance Mechanism for Optical Disk Drives.

2002 ◽  
Vol 68 (675) ◽  
pp. 3186-3192 ◽  
Author(s):  
Yoshihiro SATOU ◽  
Yoshiaki YAMAUCHI ◽  
Hisahiro MIKI ◽  
Shozo SAEGUSA ◽  
Takashi KOHNO ◽  
...  
Keyword(s):  
Design Method ◽  
Optical Disk ◽  
Disk Drives ◽  
Balance Mechanism

Optimization Design of Gravity Compensation System for a 5-DOF Articulated Heavy-Duty Robot

2014 ◽  
Vol 556-562 ◽  
pp. 2359-2364
Author(s):  
Lei Liu ◽  
Bo Huang ◽  
Yan He Zhu ◽  
Jie Zhao
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Dynamic Performance ◽  
Compensation System ◽  
Parameters Optimization ◽  
Gravity Compensation ◽  
Heavy Duty ◽  
Balance System ◽  
Optimization Parameters ◽  
Position Parameter

Spring loaded balance system is a common method for designing the gravity compensation system of heavy-duty robot. In the design process of this system, the relevant parameters of the spring itself and spring loaded balance system’s installation position parameter have a great impact on the final compensation effect. This paper introduces a parameters optimization design method of heavy-duty robot’s spring loaded balance system. Based on the dynamics equation of heavy-duty robot, we built a mathematical model of the balanced joint with spring loaded balance system. The torque of balanced joint in this model and the relevant parameters of spring loaded balance system are the optimization goal and the optimization parameters relatively. Then we obtained the optimization result of spring loaded balance system’s parameters using optimization toolbox of MATLB. By the above method, we designed and optimized the spring loaded balance system of a 5-DOF articulated heavy-duty robot. Through the comparison of the result calculated by MATLB, the optimized spring loaded balance system greatly reduces the torque of balanced joint and the consumption of joint drive. Meanwhile, by this method, the optimized spring loaded balance system maximally improves the dynamic performance and service life of the heavy-duty robot.

scholarly journals Toward mission-dependent long robotic arm enhancement: design method of flying watch attachment allocation based on thrust drivability

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Siyi Pan ◽  
Gen Endo
Keyword(s):  
Design Method ◽  
Automated Design ◽  
Human Experience ◽  
Robotic Arm ◽  
End Effector ◽  
Robotic Arms ◽  
Performance Metric ◽  
Compensation Mechanisms ◽  
Reaction Forces ◽  
External Forces

AbstractLong robotic arms are useful for many applications such as nuclear plant decommissioning, inspection, and firefighting. A major problem for designing and operating long robotic arms is that even small end effector reaction forces and arm gravity can result in large loads on proximal arm joints because of long moment arms. To solve that problem, previous researches focus on specifically designed long arms with certain compensation mechanisms. However, those specialized arm designs are difficult to be applied to existing long robotic arms and to be customized for different missions. To overcome those two drawbacks, we recently proposed a watch-like thrust-generating modular device, called flying watch, with the following two major advantages. Firstly, flying watch can be attached to different kinds of existing long robotic arms and generate thrusts to enhance arm strength. And we have proposed a thrust planning method for flying watch in our previous work. Secondly, since different flying watch attachment allocations can enhance the same robotic arm in different ways, flying watch attachment allocations can be customized to meet the needs of a specific mission. However, up to now, customizing flying watch attachment allocations to different missions is still based on human experience and there is no clear performance metric and automated design method for flying watch attachment allocation. To facilitate mission-dependent long arm enhancement, in this paper, we first propose a novel performance metric, called thrust drivability, which measures the ability of a flying watch attachment allocation to counteract unexpected end effector reaction forces. Then based on thrust drivability, we propose an automated design method, called Allocation Optimization based on Weighted Situations (AOWS), for generating mission-dependent flying watch attachment allocations counteracting both unexpected and known external forces. Simulations show that AOWS based allocation designs can counteract both known and unexpected external forces much better than human-experience-based allocation designs.

scholarly journals Design and Prototype of Variable Gravity Compensation Mechanism (VGCM)

2011 ◽  
Vol 23 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Naoyuki Takesue ◽  
◽  
Takashi Ikematsu ◽  
Hideyuki Murayama ◽  
Hideo Fujimoto ◽  
...  
Keyword(s):  
Equilibrium Position ◽  
Gravity Compensation ◽  
Compensation Mechanism ◽  
Constant Weight ◽  
Compensation Mechanisms ◽  
Variable Gravity

A machine moving vertically requires strong gravitational resistance. Gravity compensation mechanisms devised to reduce actuator force mostly compensate for constant weight, but practical use requires that the mechanism compensate for weight variations. This paper presents a Variable Gravity Compensation Mechanism (VGCM) that uses two types of linear springs and changes the equilibrium position of one. The mechanism principle is described and the prototype is designed. Performance is experimentally confirmed.

Industrial Exoskeletons With Gravity Compensation Elements

2021 ◽  
pp. 198-216
Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrey Yatsun
Keyword(s):  
Mathematical Model ◽  
Energy Consumption ◽  
Elastic Element ◽  
Knee Joints ◽  
Gravity Compensation ◽  
Electric Drives ◽  
Compensation Systems ◽  
Gravity Compensator ◽  
Prototype Design

The chapter approaches the issues of modeling the process of load lifting by a person while wearing an exoskeleton. The classification of existing gravitational compensation systems for industrial exoskeletons is shown, as well as examples of its use. A mathematical model of lifting a person's load in the exoskeleton is presented, as well as numerical parameters are calculated. It is shown that the introduction of an elastic element reduces the level of energy consumption during work, and can also facilitate the level of the worker. Industrial exoskeleton prototype design is presented. A particular focus is given to studying the influence of the gravity compensator on the magnitude of the moments generated by the electric drives of the hip and knee joints. It is shown that the use of gravity compensators enables to reduce significantly the load on electric drives.

scholarly journals DESIGN AND INVESTIGATION OF RESISTOR MATRIX FOR ACTIVE ANALOG RC FILTERS

2020 ◽  
Vol 12 (0) ◽  
pp. 1-7
Author(s):  
Leonid Kladovščikov ◽  
Romualdas Navickas
Keyword(s):  
Integrated Circuit ◽  
Design Method ◽  
Process Variations ◽  
Cmos Technology ◽  
Matrix Structure ◽  
Passive Components ◽  
Technology Node ◽  
Self Tuning ◽  
Accurate Comparison ◽  
Tuning Systems

Resistor matrixes are widely used in active RC filters as well as in self-tuning systems. Using self-tuning systems for active RC filters, it is possible to automatically tune various parameters of filter – cut-off frequency, gain and quality of filter. Most recent multiband transceivers employ higher order filters for fine bandpass filtering, thus number of passive components increases. In this work, a novel resistor matrix structure and design method is proposed. Proposed resistor matrix structure compensates both integrated circuit process variations and temperature change. Proposed resistor matrix is designed using 0.18 μm TSMC CMOS technology node and investigated using Cadence Virtuoso software. For most accurate comparison of different resistor matrices, all of them were designed in same technology node using design techniques described in other authors’ works.

Design Method of Spring Balance Mechanism Through Derivation of General Solution

2019 ◽  
Vol 31 (2) ◽  
pp. 305-316 ◽  
Author(s):  
Kazuki Kaneda ◽  
Hirokazu Yamagata ◽  
Toshio Morita ◽  
◽  
Keyword(s):  
General Solution ◽  
Conventional Method ◽  
Design Method ◽  
Solution Space ◽  
Design Solution ◽  
Trial And Error ◽  
Mechanical Device ◽  
Spring Balance ◽  
Design Solutions ◽  
Balance Mechanism

The present study set out to devise a means of designing a spring-balance mechanism (hereinafter, a SBM) based on a general solution. The goal was to apply a general solution as a guideline for identifying the optimum design solution. A SBM is used to reduce the actuator output in the design of a mechanical device. As a result, the effect of gravity can be offset and energy-saving in operation can be realized. To date, however, SBMs have been designed on a trial and error basis, with a reliance on the designer’s knowledge or experience. Thus, in some instances, it may not be possible to identify a design solution that should, in theory, be achievable. To overcome this issue, this study examined the application of a general solution to the design of a SBM. Such a general solution would identify a solution space including viable design solutions. Subsequently, once a design that satisfies the general solution had been identified, a search could be made of all the design solutions within the solution space. First, the sequence whereby the general solution is used to identify a SBM design that satisfies the general solution, thus providing a guideline for the search action, is determined. Herein, the method used to identify this initial SBM design is presented. The devised method is based on the description of an energy-conservation formula that does not involve any trial and error. The proposed method incorporates a conventional method into the design solution, which can be derived when the conventional method cannot identify a design solution. As a result, a design method using a general solution for the design of an SBM is realized.

Implementation of Reliability Evaluation Into JSME Fast Reactor Codes: 1 — Current Status and Path Forward

2016 ◽  
Author(s):  
Tai Asayama ◽  
Shigeru Takaya
Keyword(s):  
Fast Reactor ◽  
Design Method ◽  
Reliability Evaluation ◽  
Resistance Factor ◽  
Current Status ◽  
Japan Society ◽  
Passive Components ◽  
Evaluation Methodologies ◽  
Factor Design ◽  
Load And Resistance Factor

This paper describes the current status and path forward of the ongoing activities in the Japan Society of Mechanical Engineers to implement reliability evaluation methodologies into the fast reactor codes and standards. The activities are going on on two aspects; design and inservice inspection. For design, methodologies are being developed to implement a reliability-based method for the evaluation of buckling of vessels using the Load and Resistance Factor Design method. With regards inservice inspection, in order to establish a methodology that takes account of the reliability of components when setting inspection requirements, evaluations are being performed on major passive components of fast reactors. To support the process, guidelines for reliability evaluation are being developed. The efforts to standardize reliability evaluation methodologies will be continued. One of the most important remaining issues is establishing a framework on which target reliabilities could be determined by the consensus of stakeholders.

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