Set Of Experimental System Research Articles

Design and Control of Pneumatic Muscle-Driven Robot Arm Based on Bilateral Rehabilitation Training

As a new treatment method, the upper limb rehabilitation training robot can help stroke hemiplegic patients recover their upper limb motor function by providing repetitive exercises and other ways. In this paper, based on the background of bilateral rehabilitation training with pneumatic muscle-driven robot arm containing paw system, the key technology of benevolence is systematically studied, and a set of experimental system is designed to verify the research results in detail. The mechanism design of the humanoid multi-joint double-arm is completed by imitating the human arm. Pneumatic artificial muscles are used to drive the shoulder and elbow joints of the mechanical arm, and stepping motors are used to drive auxiliary motion joints. The designed mechanical arm has both flexibility and compactness in structure. This study provides a useful reference for improving the effectiveness of arm design of upper limb rehabilitation pneumatic muscle-driven robot, and is helpful to broaden the research ideas of upper limb rehabilitation robot.

Visual Locating of Reactor in an Industrial Environment Using the Composite Method.

To achieve an automatic unloading of a reactor during the sherardizing process, it is necessary to calculate the pose and position of the reactors in an industrial environment with various amounts of luminance and floating dust. In this study, the defects of classic image processing methods and deep learning methods used for locating the reactors are first analyzed. Next, an improved You Only Look Once(YOLO) model is employed to find the region of interest of the handling hole and a handling hole corner detection method based on the image morphology and a Hough transform is presented. Finally, the position and pose of the reactors will be obtained by establishing a 3D handling hole model according to the principle of a binocular stereo system. To test the performance of the proposed method, a set of experimental systems was set up and experiments were conducted. The results indicate that the proposed location method is effective and the precision of the position recognition can be controlled to within 4.64 mm and when the cameras are approximately 5 m away from the reactor, meeting the requirements.

Qualitative and quantitative investigation on concentration of indoor dense gas caused by leakage and diffusion

A set of experimental system was built to study the concentration field change and influencing factors for the leakage and diffusion of indoor dense gas. CO2 was used in the experiment. CO2 gas tends to settle down after leakage. CO2 gas concentration values are disparate at different positions in the same height. It takes longer time to get the same CO2 gas concentration at higher positions than low positions. The concentration distribution is relatively approximate in the horizontal plane near the ground, while an uneven distribution is shown in the vertical plane. The concentration values increase with an increase in the leakage source strength at the positions which are lower than release source. Gas concentration is relatively stable at lower positions, while the fluctuation of gas concentration appears at higher positions. When the leakage source height is higher, the concentration near the ground reduces under the same condition. However, the whole space has a higher CO2 concentration which can generate greater risk. Incidence angle plays a great role in CO2 concentration. A theoretical calculation method was presented to predict CO2 concentration. The validation of the computation method was made by comparison of experimental data with calculation results. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 424–434, 2019

A long range piezoelectric rotary motor with continuous output: Design, analysis and experimental performance

This study proposes a novel piezoelectric rotary motor which can output long range continuous motion. With the help of two piezo-stacks which are located at a 90° included angle, the motor can achieve circular motion trajectory of a cylindrical driving surface and the rotor can be driven by the cylindrical surface to deliver long range continuous rotary motion without pause. The structure and operational principle are introduced in detail. The stiffness of the flexure hinge system is theoretically calculated and the result is verified by finite element analysis. A prototype of the proposed motor is manufactured and a set of experimental system is established to investigate the performance of the prototype. The experimental results confirm that the motor prototype can output long range continuous rotary motion stably. With the driving frequency increasing, the angular velocity of the prototype increases gradually while the angular acceleration decreases gradually. The angular velocity can reach 221,321μrad/s when the driving frequency is 512Hz. The maximum loading capacity is about 2.65N and the maximum output torque is about 4.94Nmm when the driving voltage and frequency are 150V and 1Hz. The return error of the prototype is about 608μrad during the forward stroke of 28,970μrad and the error percentage is about 2.1%. We can obtain a satisfactory angular velocity by choosing a proper frequency for the motor.

Design, analysis and experimental performance of a piezoelectric rotary actuator based on compliant foot driving

This study proposes a piezoelectric rotary actuator based on compliant foot driving. With the help of driving modules which are composed of four compliant feet and four piezo-stacks, the designed actuator can produce large range rotary motions in both forward and backward directions with a high resolution. The mechanical structure and the moving principle are presented. Pseudo-rigid-body model is used to simulate the path of the compliant foot end and the movement model of the driving module is established to analyze the motion of the actuator. The influence of the preload force on performance of the actuator is discussed. To investigate the working performance, a prototype is fabricated and a set of experimental system is established. The experimental results indicate that the angular displacement outputs under various driving voltages and frequencies show good linear relationships with the time. The driving resolution and the maximum output force are 0.24 µrad and 158 N, respectively. The angular displacements deviation between the forward and backward motions within 50 steps is 376.4 μrad and the actuator can achieve various angular velocities by changing the driving voltage and frequency.

Study on the Energy Harvesting Performance of PE Cantilever Beam

Harvesting ambient vibration energy through piezoelectric (PE) means is a popular energy harvesting technique. The merit of applying PE means to supply energy for microelectronic devices is that they can reduce the battery weight and possibly make the device self-powered by harvesting mechanical energy. This investigation will examine the energy generating performance of miniature PE cantilever beam through theoretical modeling, simulation and experiment testing. Through the theoretical analysis of the piezoelectric energy harvesting structure, the expression of open circuit voltage output is obtained. Using ANSYS software, the working performance of piezoelectric cantilever beam is analyzed. On the basis of theoretical analysis and simulation optimization, a set of experimental system is established to test the energy harvesting performance of the piezoelectric cantilever beam. The testing result shows that the harvested energy by the piezoelectric cantilever beam could supply electrical power to some micro electrical devices.

Parallel Rolling Robot with Hydraulic Driven Expandable Chain

A novel three degrees of freedom(DOF) parallel rolling robot is proposed. The main consideration for proposing the robot aims at acquiring large deformation capability,powerful strength output,rapid response and flexible locomotion. The robot adopts the parallel mechanism as its architecture to guarantee the stiffness of the robot. The large deformation capability is obtained by taking advantage of the planar expandable mechanism as the extension ratio enlarging mechanism. The usage of the hydraulic actuation as the telescopic input increases the locomotion flexibility and the strength output of the robot. The robot rolls by properly planning and controlling the relations between the center of mass(CM) of the robot and the supporting region. The mechanical construction and configuration of the robot is described,the rolling gaits are planned,and the optimal locomotion rule is given. Based on the rule,the kinematic model of the robot is built. The correctness of the kinematic model is verified by the given numerical example. The locomotion feasibility of the two locomotion periods is analysed. A set of experimental system including the hydraulic system and robotic system is built. Four rolling experiments are carried out accordingly. The experimental results demonstrate that the experimental system is reliable and possesses the rapid response capability,and verify that the validity and feasibility of the theoretical analysis and the rolling locomotion.

A Kind of Experiment System Design of Stepping Motor

Thispaper designs a set of experiment system for stepper motor, the control system ofstepping motor is composed of stepper controller, drive and stepper motor, withthe single chip processor as the stepper motor controller to realize the morecomplex stepper motor control function. This system has got good teachingeffect in experiment teaching.

The Basic Investigation on Catalytic Oxidation of Mine Gas to Methanol in Liquid Phase

A set of experimental system was self-designed and made for liquid phase catalytic oxidation of gas to methanol. It was used to investigate the impacts of catalyst and reaction conditions on catalytic oxidation of gas to methanol in acetic acid solution, and to analyze its reaction mechanism. It has been showed that the yield of the methanol is 1840 μmol under the catalysis of 0.5 g of 0.5% Pd-CuPc/Y and the following conditions: CH3COOH:H2O = 4:1 (v/v), 1000 μmol of p-benzoquinone; reaction time, 3 h; reaction temperature, 150°C; gas composition, 2.5MPa CH4+0.4MPaO2 +0.4MPa N2; in acetic acid solution, catalytic oxidation of mine gas to methanol follows mechanisms of electrophilic substitution and oxidation of reactive oxygen species (ROS).

The Experiment for Vertical Rectangular Micro-Channel Flow Boiling

To further deepen exploration of boiling in micro-channels a set of experiment system for micro-channel flow boiling is homemade, which includes experimental equipment required and experimental pieces of the design process. The channel is width of 100mm, length of 1200mm, and the groove depth of 95mm. The gasket thickness is 0.5mm, 1.0mm, 1.5mm or 2.0mm.

The Research of the Effect of Dynamic Load and Temperature on the Diffusion Performance of Chlorideion in Concrete

The diffusion performance of chloride ion in concrete under the coupling action of dynamic load and environment was researched by a new set of experimental system. The experiment are composed of study of saturated performance of concrete, diffusion performance of chloride ion with different water binder ratio and under coupling action of dynamic load and temperature. The results show that the transport mechanism of chloride ion in concrete accounted with diffusion theory due to the 99% of saturation degree of concrete; the diffusion coefficient of chloride ion is decreased with the increasing water binder ratio, but is increased with temperature increase; and the diffusion coefficient of chloride ion is changed with cycle number.

Study on Minimum Propagation Current of Bi-2223/Ag Superconducting Multifilament Tape

Minimum propagation current of Bi-2223/Ag superconducting multifilament tape was studied in detail, including experimental investigation and numerical calculation using finite element method (FEM). A set of experimental system has been established, quench propagation velocities with various transport current have been measured and minimum propagation current has been obtained in the condition of N2 gas cooling. The effect of parallel background magnetic field on minimum propagation current has also been studied experimentally. In addition, minimum propagation current at different operating temperature has been gained by the simulated calculation using FEM.It has been found that the high temperature superconductor is stable if only transport current is smaller than minimum propagation current of the time no matter what condition it is in. Minimum propagation current can be considered as an important stability criterion of high temperature superconductor.

Limited-jerk optimal time-delayed filter suppressing residual oscilation of crane payload

When time-delayed filtering techniques are used in the high speed and large tonnage cranes, the residual oscillations of the payload can be efficiently suppressed, simultaneously, impact motion of drive mechanism is induced and the response speed of the system is slowed. Aiming at theproblems, the limited-jerk optimal time-delayed filter, which combines the limited-jerk theory and optimization theory, is presented. Based on the idea of reducing motion impact of the rigid body in flexible systems, the limited-jerk control command is designed, which can suppress the high frequency components in the control input and reduce the excitation to un-modeled harmonic modes. Then, taking the state vector of payload oscillation as quadratic objective function, the delay time with the least payload swing is calculated according to the optimization theory and the optimal time-delayed filter with appropriate time-delay is developed, which make the system have satisfying response speed. The limited-jerk control commands from the filter are composed of a sequence of ramp signals, whose time-ratio of variation will not exceed the permissible value, thus the motion impact of rigid body is suppressed. A set of simulation system and a set of experiment system for gantry cranes are built, in which the validity of the proposed control technique are proven.

First-order statistical properties of ultrasonic speckles back-scattered from a kind of weak scattering interface

First-order statistical properties of ultrasonic speckles back-scattered from an interface with tiny pints on, which is considered as one kind of weak scatterin g interface, are studied in this paper. Based on four assumptions, theoretical a nalyses indicate that the amplitude of ultrasonic speckles in space is in the fo rm of Rice distribution, and the phase probability density function of the ultra sonic speckles is a compound function of Gauss distribution function and Gauss p robability integral function. When the density of the pits on the interface is v ery high, the amplitude of ultrasonic speckles becomes Rayleigh distributed. To verify the theoretical analysis conclusion, the amplitude probability distributi on of ultrasonic speckles is measured by using a set of experimental systems wit h step scanning controlled by a computer, which is built by the authors. The exp erimental results are in good agreement with the theoretical predicted results. So, the assumptions proposed in this paper are suitable for the theoretical anal yses.

Relative roles of top‐down and bottom‐up forces in terrestrial tritrophic plant–insect herbivore–natural enemy systems

Whether resources (bottom‐up forces), natural enemies (top‐down forces), or both, determine the abundance of insect herbivore populations in plant–insect herbivore–natural enemy systems remains a major issue in population ecology. Unlike recent surveys of the tritrophic literature we do not seek to quantify whether top‐down or bottom‐up forces predominate in any given set of experimental systems. Acknowledging the dearth of empirical synthesis we employ two contrasting literature surveys to determine whether the plant–insect herbivore–natural enemy literature is currently adequate to form a conceptual synthesis of the relative roles of top‐down and bottom‐up forces. The emergence of a synthesis of the relative roles of top‐down and bottom‐up forces in plant–insect herbivore–natural enemy systems appears to have been largely prevented by (1) the absence of appropriate empirical data; (2) failure to appreciate the merits of existing data; (3) a continued desire to emphasise either top‐down or bottom‐up forces to the exclusion of the other; and (4) confusion regarding which processes regulate and which influence the abundance of insect herbivores.

Techniques for the control of chaos

Abstract The concepts of chaos and its control are reviewed. Both are discussed from an experimental as well as a theoretical viewpoint. Examples are then given of the control of chaos in adiverse set of experimental systems. Current and future applications are discussed.

Inhibition of T-lymphocyte-mediated tumor-specific lysis by alloantisera directed against the H-2 serological specificities of the tumor.

After appropriate in vivo or in vitro immunization, cytotoxic T lymphocytes (CTL) are generated which efficiently kill cells bearing particular membrane antigens in common with the immunizing cell (reviewed in reference 1). Such CTL have been most thoroughly studied in mice, employing alloimmunization with cells differing at the major histocompatibility locus, H-2. in such cases, the predominant cell surface antigens recognized by the CTL appear to be the molecules carrying the serologically defined H-2 specificities, coded for by the K and D regions of the H-2 complex (2). In other syngeneic models of cell-mediated specific cytolysis, involving lymphocyte chariomeningitis (LCM) virus- or ectromelia virus-infected cells or TNP-modified lymphoid cells, thymus-derived cells also constitute the main effector cell type. The CTL generated in these latter systems function most efficiently when virus-infected or TNP-modified target cells share identitites at the H-2K or H-2D loci with the effector CTL and stimulator cells (3-5). Another set of experimental systems in which CTL are generated and play a significant biological role is that of immunity to tumor-associated antigens (TAA) (6). The nature of the TAA which the CTL recognize is only beginning to be understood. Several recent reports indicated the existence of physiochemical and/or antigenic relationships between TAA and H-2 antigens (7,8). These relationships, together with the genetic restrictions cited above in the generation of CTL involving products of the H-2K or H-2D loci suggested the possibility that in certain tumor systems, the TAA which are able to most effectively stimulate CTL responses might be structurally similar to, or linked with, the H-2K or H- 2D molecules on the tumor surface. It has been previously demonstrated in allogenic models that antisera specific for the appropriate H-2K or H-2D products present on a target cell could specifically block CTL-mediated lysis (1,9). This report demonstrates that certain anti-H-2 alloantisera specific for the target tumor cells can block lysis of those target cells mediated by syngeneic tumor-specific CTL effector cells.