Towards Online Impact Force Dynamic Parameters Identification for Hydraulic Legged Robots

2016 ◽  
Author(s):  
Mariapaola D’Imperio ◽  
Ferdinando Cannella
Keyword(s):  
Rate Increase ◽  
Impact Force ◽  
Reaction Force ◽  
Experimental Tests ◽  
Parameters Identification ◽  
Legged Robots ◽  
Stable Manner ◽  
Impact Phenomena ◽  
Design Integration ◽  
And Control

The design and control of legged robots capable of performing dynamic tasks, such as those involving impact in a stable manner, is of growing concern within the robotics community. Under these conditions, ground reaction force rate increase dramatically and, if the control system fails to response appropriately, the internal vibrations will damage the robotic structure. To deal with these problems, design integration between control, mechanics and electronics is required. As a means to co-develop these tasks, we present an alternative method, based on the Virtual Prototyping (VP) and cosimulation concept, to model impact phenomena for design purposes. This model has been built starting from the identification of all the parameters that affect object dynamics within the mechanical structure. Two campaigns of experimental tests have been carried out: the first one for the parameters identification, while the second one for the model validation process. The agreement between numerical results and experiments is very satisfactory, demonstrating the possibility of using the model for future mechanical and control co-development.

scholarly journals Experimental Strain Measurement Approach Using Fiber Bragg Grating Sensors for Monitoring of Railway Switches and Crossings

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola
Keyword(s):  
Fiber Bragg Grating ◽  
Experimental Tests ◽  
Cost Effective ◽  
Measuring Method ◽  
Bragg Grating ◽  
Railway Network ◽  
System Failures ◽  
Railway Infrastructure ◽  
Train Speed ◽  
And Control

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.

Development of a Ring Permeability Test System

2010 ◽  
Vol 136 ◽  
pp. 153-157
Author(s):  
Yu Hong Du ◽  
Xiu Ming Jiang ◽  
Xiu Ren Li
Keyword(s):  
Control System ◽  
Control Method ◽  
Dynamic Performance ◽  
Experimental Tests ◽  
Measuring Method ◽  
Test System ◽  
Fluid Theory ◽  
And Control ◽  
Relationship Of ◽  
The Mathematical Model

To solve the problem of detecting the permeability of the textile machinery, a dedicated test system has been developed based on the pressure difference measuring method. The established system has a number of advantages including simple, fast and accurate. The mathematical model of influencing factors for permeability is derived based on fluid theory, and the relationship of these parameters is achieved. Further investigations are directed towards the inherent characteristics of the control system. Based on the established model and measuring features, an information fusion based clustering control system is proposed to implement the measurement. Using this mechanical structure, a PID control system and a cluster control system have been developed. Simulation and experimental tests are carried out to examine the performance of the established system. It is noted that the clustering method has a high dynamic performance and control accuracy. This cluster fusion control method has been successfully utilized in powder metallurgy collar permeability testing.

Supporting Co-Design of Physical and Control Architectures of Mechatronic Systems

2011 ◽  
Author(s):  
Andre´s A. Alvarez Cabrera ◽  
Hitoshi Komoto ◽  
Tetsuo Tomiyama
Keyword(s):  
Control Structure ◽  
Mutual Influence ◽  
Early Stage ◽  
Physical Structure ◽  
Mechatronic Systems ◽  
Design Problems ◽  
Software And Hardware ◽  
Design Integration ◽  
And Control ◽  
Recent Tendency

There is a rather recent tendency to define the physical structure and the control structure of a system concurrently when designing the architecture of a product, i.e., to perform codesign. We argue that co-design can only be enabled when the mutual influence between physical system and control is made evident to the designer at an early stage. Though the idea of design integration is not new, to the best of our knowledge, there is no computer tooling that explicitly supports this activity by enabling co-design as stated before. In this paper the authors propose a method for co-design of physical and control architectures as a better approach to design mechatronic systems, allowing to exploit the synergy between software and hardware and detecting certain design problems at an early stage of design. The proposed approach is supported by a set of tools and demonstrated through an example case.

scholarly journals Analysis of a debris flow after Wenchuan Earthquake and discussion on preventive measures

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1563-1570
Author(s):  
Zhi-Long Zhang ◽  
Jing Xie ◽  
De-Ke Yu ◽  
Zhi-Jie Wen
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Preventive Measures ◽  
Impact Force ◽  
Site Investigation ◽  
The Wenchuan Earthquake ◽  
Formation Conditions ◽  
National Road ◽  
And Control ◽  
Debris Flow Disaster

This paper addresses a debris flow disaster in Yingxiu town after the Wenchuan earthquake. Through site investigation and data review, the geography and geological environment of the basin and the development, formation conditions and activity characteristics of the debris flow in the basin are analyzed. Calculate and analyze the characteristics of the debris flow, such as gravity, flow velocity and impact force. According to the management idea of combination of blocking and discharging, this paper proposes to arrange three blocking dams in the main ditch, construct drainage gullies in the downstream accumulation section, and prevent and control the aqueduct in the intersection of the main ditch and the G213 national road, which will be similar to the earthquake in the future. It is provided as a reference for research and prevention of the debris flow.

scholarly journals Modeling and Control of Legged Robots

2016 ◽  
pp. 1203-1234 ◽  
Author(s):  
Pierre-Brice Wieber ◽  
Russ Tedrake ◽  
Scott Kuindersma
Keyword(s):  
Legged Robots ◽  
Modeling And Control ◽  
And Control

A 6-Week Transition to Maximal Running Shoes Does Not Change Running Biomechanics

2019 ◽  
Vol 47 (4) ◽  
pp. 968-973 ◽  
Author(s):  
J.J. Hannigan ◽  
Christine D. Pollard
Keyword(s):  
Ground Reaction Force ◽  
Loading Rate ◽  
Impact Force ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Risk Of Injury ◽  
Impact Peak ◽  
Running Shoes ◽  
Vertical Ground ◽  
The Impact

Background: A recent study suggested that maximal running shoes may increase the impact force and loading rate of the vertical ground-reaction force during running. It is currently unknown whether runners will adapt to decrease the impact force and loading rate over time. Purpose: To compare the vertical ground-reaction force and ankle kinematics between maximal and traditional shoes before and after a 6-week acclimation period to the maximal shoe. Study Design: Controlled laboratory study. Methods: Participants ran in a traditional running shoe and a maximal running shoe during 2 testing sessions 6 weeks apart. During each session, 3-dimensional kinematics and kinetics were collected during overground running. Variables of interest included the loading rate, impact peak, and active peak of the vertical ground-reaction force, as well as eversion and dorsiflexion kinematics. Two-way repeated measures analyses of variance compared data within participants. Results: No significant differences were observed in any biomechanical variable between time points. The loading rate and impact peak were higher in the maximal shoe. Runners were still everted at toe-off and landed with less dorsiflexion, on average, in the maximal shoe. Conclusion: Greater loading rates and impact forces were previously found in maximal running shoes, which may indicate an increased risk of injury. The eversion mechanics observed in the maximal shoes may also increase the risk of injury. A 6-week transition to maximal shoes did not significantly change any of these measures. Clinical Relevance: Maximal running shoes are becoming very popular and may be considered a treatment option for some injuries. The biomechanical results of this study do not support the use of maximal running shoes. However, the effect of these shoes on pain and injury rates is unknown.

Design and Underwater Tests of Subsea Walking Hexapod MAK-1

2016 ◽  
Author(s):  
Vadim V. Chernyshev ◽  
Vladimir V. Arykantsev ◽  
Andrey E. Gavrilov ◽  
Yaroslav V. Kalinin ◽  
Nikolay G. Sharonov
Keyword(s):  
Movement Control ◽  
Experimental Tests ◽  
Energy Usage ◽  
Walking Machine ◽  
Walking Machines ◽  
Sea Bottom ◽  
Different Types ◽  
Robotic Devices ◽  
And Control ◽  
System Power

An important role among machines for sea bottom exploration is assigned to the autonomous ground devices. Some rescue tasks also require subsea robotic devices. The main purpose of the work is to investigate and improve adaptive characteristics, traction properties and control methods of cyclic walking movers in underwater conditions. Traction properties of walking machines, which moves at sea bottom was analyzed. Some experience of development and experimental tests of the walking robot “Vosminog”, designed for work at weak and waterlogged grounds. Dynamic model of a walking machine has been shown. Studied an opportunity to increase adaptive characteristics and shape passableness of walking machines. Also design and results of underwater tests of subsea walking unit MAK-1 are discussed. During tests the performance of a walking unit has been checked and the influence of design features of a walking mover on its traction characteristics and ground passability has been investigated. Some details about control system, power system and energy usage, vertical motions and accelerations for different types of walking and conditions of movement has been given. Also, certain attention was given to testing of methods of standalone movement control of subsea unit in conditions of incomplete and ambiguous vision of current situation. Tests have shown that walking movers in subsea conditions can provide higher traction properties, in comparison with wheeled and tracked ones. The unit can be used for exploration of seabed resources and for rescue tasks.

Design and Performance Study of a Novel Minimally Invasive Active Surgical Needle

2019 ◽  
Vol 13 (4) ◽  
Author(s):  
Zahra Khashei Varnamkhasti ◽  
Bardia Konh
Keyword(s):  
Experimental Tests ◽  
Needle Insertion ◽  
Integrated System ◽  
Performance Study ◽  
Medical Treatments ◽  
Tissue Phantom ◽  
Sma Actuator ◽  
Potential Improvement ◽  
And Performance ◽  
And Control

Abstract Many medical treatments such as brachytherapy, thermal ablation, and biopsy are performed using percutaneous needle-based procedures. The success of these procedures highly depends on accurate placement of the needle tip at target positions. A novel active needle was designed and developed in this work that can steer inside the tissue via a shape memory alloy (SMA) actuator attached to its body. With actuation and control offered by the actuator, the active needle can reach the target positions with more accuracy, and thereby potential improvement in clinical outcomes. An integrated system was also developed to robotically operate the active needle insertion. The performance of the active needle was evaluated with finite element methods and experimental tests on a fabricated prototype in air. Active needle insertion tests in a tissue phantom were also performed to evaluate the performance of the active needle. The deflection in air and tissue phantom demonstrated the capability of the active needle to reach target positions.

scholarly journals Landing Control of Foot with Springs for Walking Robots on Rough Terrain

10.5772/7238 ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 25 ◽  
Author(s):  
Moyuru Yamada ◽  
Shigenori Sano ◽  
Naoki Uchiyama
Keyword(s):  
Controller Design ◽  
Impact Force ◽  
Reaction Force ◽  
Walking Robots ◽  
Flat Surfaces ◽  
Uneven Terrain ◽  
Biped Walking Robot ◽  
Foot Position ◽  
The Impact ◽  
Landing Control

Landing control is one of the important issues for biped walking robot, because robots are expected to walk on not only known flat surfaces but also unknown and uneven terrain for working at various fields. This paper presents a new controller design for a robotic foot to land on unknown terrain. The robotic foot considered in this study equips springs to reduce the impact force at the foot landing. There are two objectives in the landing control; achieving the desired ground reaction force and positioning the foot on unknown terrain. To achieve these two objectives simultaneously by adjusting the foot position, we propose a PI force controller with a desired foot position, which guarantees the robust stability of control system with respect to terrain variance, and exact positioning of the foot to unknown terrain. Simulation results using the Open Dynamics Engine demonstrate the effectiveness of the proposed controller.

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