Omni-Directional Gait of Multi-Legged Robot on Rough Terrain by Following the Virtual Plane

2012 ◽  
Vol 24 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Kenji Kamikawa ◽  
◽  
Tomohito Takubo ◽  
Yasushi Mae ◽  
Kenji Inoue ◽  
...  
Keyword(s):  
High Speed ◽  
Rotational Symmetry ◽  
Stable State ◽  
Rough Terrain ◽  
Real Time Processing ◽  
Touch Sensor ◽  
Working Space ◽  
Single Pattern ◽  
Virtual Plane ◽  
Cylindrical Working

This paper proposes a simple gait algorithm for multilegged robots on slopes or rough terrain. This algorithm enables a robot follow a virtual plane defined by grounding points of the legs. The robot does not recognize the surrounding rough terrain. This proposed algorithm has been applied to an actual robot and proven. The robot has a touch sensor on the tip of each leg. The sensors detect contact with the ground, allowing the leg to be planted stably. When the robot moves over rough terrain, the robot body inclines as if becoming parallel to the virtual plane that is defined by the support points of the legs. The ASTERISK robot to which the algorithm has been applied has six limbs that radiate out in six directions, giving it rotational symmetry. Each leg of the robot has a cylindrical working space; the robot can move omnidirectionally without changing its posture. The movement algorithm is an easy, single-pattern operation that maintains a stable state at all times, and the robot can move without high-speed, real-time processing. The operation and effectiveness of this algorithm are verified on a slope and on steps through the experiment.

LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

2017 ◽  
Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Models ◽  
Stable State ◽  
Landslide Risk ◽  
Kuibyshev Reservoir ◽  
Stepped Surface ◽  
The Stability ◽  
Landslide Slope ◽  
The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

Ultrasonic sensor system for the uses in intelligent motion control system of a mobile robots group

2010 ◽  
Vol 7 ◽  
pp. 109-117
Author(s):  
O.V. Darintsev ◽  
A.B. Migranov ◽  
B.S. Yudintsev
Keyword(s):  
Control System ◽  
Mobile Robot ◽  
Mobile Robots ◽  
Motion Control ◽  
High Speed ◽  
Ultrasonic Sensor ◽  
Sensor System ◽  
Motion Control System ◽  
Speed Sensor ◽  
Working Space

The article deals with the development of a high-speed sensor system for a mobile robot, used in conjunction with an intelligent method of planning trajectories in conditions of high dynamism of the working space.

scholarly journals Variable step control to improve scanning speed of gene sequencing stage

2021 ◽  
pp. 002029402110022
Author(s):  
Xiaohua Zhou ◽  
Jianbin Zheng ◽  
Xiaoming Wang ◽  
Wenda Niu ◽  
Tongjian Guo
Keyword(s):  
Motion Control ◽  
High Precision ◽  
High Speed ◽  
Stable State ◽  
Gene Sequencing ◽  
Scanning Speed ◽  
Settling Time ◽  
Step Motion ◽  
Variable Step ◽  
Step Control

High-speed scanning is a huge challenge to the motion control of step-scanning gene sequencing stage. The stage should achieve high-precision position stability with minimal settling time for each step. The existing step-scanning scheme usually bases on fixed-step motion control, which has limited means to reduce the time cost of approaching the desired position and keeping high-precision position stability. In this work, we focus on shortening the settling time of stepping motion and propose a novel variable step control method to increase the scanning speed of gene sequencing stage. Specifically, the variable step control stabilizes the stage at any position in a steady-state interval rather than the desired position on each step, so that reduces the settling time. The resulting step-length error is compensated in the next acceleration and deceleration process of stepping to avoid the accumulation of errors. We explicitly described the working process of the step-scanning gene sequencer and designed the PID control structure used in the variable step control for the gene sequencing stage. The simulation was performed to check the performance and stability of the variable step control. Under the conditions of the variable step control where the IMA6000 gene sequencer prototype was evaluated extensively. The experimental results show that the real gene sequencer can step 1.54 mm in 50 ms period, and maintain a high-precision stable state less than 30 nm standard deviation in the following 10 ms period. The proposed method performs well on the gene sequencing stage.

High-speed hazard avoidance for mobile robots in rough terrain

2004 ◽  
Author(s):  
Matthew J. Spenko ◽  
Karl D. Iagnemma ◽  
Steven Dubowsky
Keyword(s):  
Mobile Robots ◽  
High Speed ◽  
Rough Terrain ◽  
Hazard Avoidance

scholarly journals Frequency Controlled Noise Cancellation for Audio and Hearing Purposes

2020 ◽  
Vol 8 (1) ◽  
pp. 270-290
Author(s):  
Ali O. Abid Noor
Keyword(s):  
Time Delay ◽  
Power Consumption ◽  
Hearing Aids ◽  
High Speed ◽  
Hearing Aid ◽  
External Noise ◽  
Noise Cancellation ◽  
Audio Signals ◽  
Real Time Processing ◽  
Full Band

Methods for hearing aids sought to compensate for loss in hearing by amplifying signals of interest in the audio band. In real-world, audio signals are prone to outdoor noise which can be destructive for hearing aid.  Eliminating interfering noise at high speed and low power consumption became a target for recent researches. Modern hearing compensation technologies use digital signal processing which requires minimum implementation costs to reduce power consumption, as well as avoiding delay in real time processing. In this paper, frequency controlled noise cancellation (FCNC) strategy for hearing aid and audio communication is developed with low complexity and least time delay. The contribution of the current work is made by offering a method that is capable of removing inherent distortion due filter-bank insertion and assigning adaptive filtering to a particular sub-band to remove external noise. The performance of the proposed FCNC was examined under frequency-limited noise, which corrupts particular parts of the audio spectrum. Results showed that the FCNC renders noise-immune audio signals with minimal number of computations and least delay. Mean square error (MSE) plots of the proposed FCNC method reached below -30 dB compared to -25 dB using conventional sub-band method and to -10 dB using standard full-band noise canceller. The proposed FCNC approach gave the lowest number of computations compared to other methods with a total of 346 computations per sample compared to 860 and 512 by conventional sub-band and full-band methods respectively. The time delay using FCNC is the least compared to the other methods.

scholarly journals Modal Kinematic Analysis of a Parallel Kinematic Robot with Low-Stiffness Transmissions

Robotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 132
Author(s):  
Paolo Righettini ◽  
Roberto Strada ◽  
Filippo Cortinovis
Keyword(s):  
High Speed ◽  
Parallel Robots ◽  
Maximum Speed ◽  
Kinematic Structure ◽  
End Effector ◽  
New Approach ◽  
Working Space ◽  
Modes Of Vibration ◽  
Parallel Kinematic ◽  
Actuated Joints

Several industrial robotic applications that require high speed or high stiffness-to-inertia ratios use parallel kinematic robots. In the cases where the critical point of the application is the speed, the compliance of the main mechanical transmissions placed between the actuators and the parallel kinematic structure can be significantly higher than that of the parallel kinematic structure itself. This paper deals with this kind of system, where the overall performance depends on the maximum speed and on the dynamic behavior. Our research proposes a new approach for the investigation of the modes of vibration of the end-effector placed on the robot structure for a system where the transmission’s compliance is not negligible in relation to the flexibility of the parallel kinematic structure. The approach considers the kinematic and dynamic coupling due to the parallel kinematic structure, the system’s mass distribution and the transmission’s stiffness. In the literature, several papers deal with the dynamic vibration analysis of parallel robots. Some of these also consider the transmissions between the motors and the actuated joints. However, these works mainly deal with the modal analysis of the robot’s mechanical structure or the displacement analysis of the transmission’s effects on the positioning error of the end-effector. The discussion of the proposed approach takes into consideration a linear delta robot. The results show that the system’s natural frequencies and the directions of the end-effector’s modal displacements strongly depend on its position in the working space.

scholarly journals Investigation of an Ablation-dominated Arc in a Model Chamber by Optical Emission Spectroscopy

2017 ◽  
Vol 4 (2) ◽  
pp. 153-156 ◽  
Author(s):  
R. Methling ◽  
A. Khakpour ◽  
S. Wetzeler ◽  
D. Uhrlandt
Keyword(s):  
Emission Spectroscopy ◽  
High Speed ◽  
Optical Emission Spectroscopy ◽  
Rotational Symmetry ◽  
Line Emission ◽  
Optical Emission ◽  
Ambient Air ◽  
Video Camera ◽  
Radial Temperature ◽  
Model Chamber

A switching arc in a model chamber is investigated by means of optical emission spectroscopy. Ignition wire is applied to initiate an arc of several kiloampere between tungsten−copper electrodes. Radiation emitted by the arc plasma is absorbed by a surrounding PTFE nozzle, leading to an ablation–dominated discharge. Video spectroscopy is carried out using an imaging spectrometer combined with a high–speed video camera. Carbon ion and fluorine atom line emission from the heating channel as well as copper, oxygen and nitrogen from ignition wire and ambient air are analyzed with focus on the low–current phases at the beginning of discharge and near current zero. Additionally, electrical parameters and total pressure are recorded while the general behavior of the discharge is observed by another video camera. Considering rotational symmetry of the arc the corresponding radial emission coefficients are determined. Finally, radial temperature profiles are calculated.

An experimental study on the cryogenic face seal at different inlet pressures

2019 ◽  
Vol 234 (9) ◽  
pp. 1470-1481
Author(s):  
Guoyuan Zhang ◽  
Yangyang Zhao ◽  
Weigang Zhao ◽  
Xiutian Yan ◽  
Maotan Liang
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
High Speed ◽  
Fluid Pressure ◽  
Stable State ◽  
Test System ◽  
Leakage Rate ◽  
Mechanical Seals ◽  
Closing Force ◽  
The Difference

An experimental test system for cryogenic high-speed hydrodynamic non-contact mechanical seals is developed. Based on this system, the performances of seals under different working conditions are studied in detail in this paper. With the experimental results, the main performances of the seals (such as inlet and outlet temperatures, separated speed, face temperature, friction force, friction coefficient, leakage rate) are obtained, and the relationships of the performances with the inlet fluid pressure, the closing force and the rotational speed are discussed. The results show that the difference between the outlet and inlet temperatures decreases with increasing inlet fluid pressure. As the speed increases, the friction force varies little and remains at a constant value. The friction coefficient of the seal is approximately 0.12 and basically does not change with the speed. The leakage rate is also maintained at approximately 190 g/s. With the increase in the closing force, the friction at the seal’s face does not change greatly, which indicates that the friction at the face is always in a stable state with the seal’s closing force.

scholarly journals Experimental Verification of the Hill-climbing Performance of Blade-Type Crawler for High-speed Rough-terrain

2017 ◽  
Vol 35 (2) ◽  
pp. 153-159
Author(s):  
Yasuyuki Yamada ◽  
Ryoichi Higashi ◽  
Gen Endo ◽  
Taro Nakamura
Keyword(s):  
Experimental Verification ◽  
High Speed ◽  
Hill Climbing ◽  
Rough Terrain ◽  
The Hill

Recent Progress of Electro-optic Polymers for Device Applications

1997 ◽  
Vol 488 ◽  
Author(s):  
Alex K-Y. Jen ◽  
Qing Yang ◽  
Seth R. Marder ◽  
Larry R. Dalton ◽  
Ching-Fong Shu
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Stable State ◽  
Optical Data Storage ◽  
Device Fabrication ◽  
Optical Data ◽  
Material System ◽  
Electro Optic ◽  
Potential Applications ◽  
Device Applications

AbstractElectro-optic (E-O) polymers have drawn great interest in recent years because of their potential applications in photonics devices such as high speed modulators and switches, optical data storage and information processing1–2. In order to have suitable materials for device fabrication, it is essential to design and develop polymeric material systems (active and passive polymers) with matched refractive indices, large E-O coefficients, good temporal and photochemical stability3–8 The E-O response of an active polymer commonly arises from the electric field induced alignment of its second-order nonlinear optical (NLO) chromophore, either doped as a guest/host system or covalently bonded as a side-chain. Because of the strong interaction among the electric dipoles, the poled structure is in a meta-stable state; the poled NLO chromophores which possess large dipole moment will tend to relax back to the randomly oriented state. As a result, the stability of the poled structure strongly depends on the rigidity of the overall material system. As it might be expected, the continuous increases of the rigidity and Tg of poled polymers imposes constraints on the selection of suitable chromophores that can survive the hightemperature poling and processing conditions. To circumvent this problem, we have developed a series of chromophores that possess conformation-locked geometry and perfluoro-dicyanovinylsubstituted electron-accepting group which demonstrate both good thermal stabilty and nonlinearity. This paper provides a brief review of these highly efficient and thermally stable chromophores and polymers for device applications.

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