Reconfigurability of the modular robot is becoming curial to be a high flexibility for the wide varieties of tasks and environments. In this paper, a novel self-reconfigurable modular robot called M 2 sbot is designed...
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ISBN:
(纸本)9781509023974
Reconfigurability of the modular robot is becoming curial to be a high flexibility for the wide varieties of tasks and environments. In this paper, a novel self-reconfigurable modular robot called M 2 sbot is designed, which has the approximate cuboid shaping structure. The unit model is with one active and five passive connection surfaces, compact structure and flexible motion. It is characterized by using the unique hook-claw docking mechanism as the docking part of the neighbor modular. And the responding controlsystem based on STM32F103VET6 is also implemented. The forward kinematic equations of the chain robot are established, and then the dynamic equation is generated by the recursive Newton-Euler method based on the global matrix description. Finally, the calculation and simulation analysis of the six-module configuration with two branches demonstrates the feasibility of the proposed method in the generation of motion equation.
The experiments of turning titanium alloy are carried out by using central composite design, the influences of cutting speed, feed rate and cutting depth on surface roughness are analyzed. The surface roughness predic...
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ISBN:
(纸本)9781509023974
The experiments of turning titanium alloy are carried out by using central composite design, the influences of cutting speed, feed rate and cutting depth on surface roughness are analyzed. The surface roughness prediction model is established based on the response surface method. The significance of the regression equation is validated and the influences of the cutting parameters on surface roughness are compared. The results show that: within the range of cutting parameters used in the experiments, the most significant parameter on surface roughness is given by feed rate, followed by cutting depth, and the cutting speed has minimal effect on surface roughness;the prediction model is significant. It can be used to select various suitable parameters before the machining processing to predict and control the surface roughness.
This paper presents a new type of multifunctional bioreactor, which is to provide cell tissue a mechanical environment which is close to the real situation. This bioreactor is based on the concept of fatigue machine, ...
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This paper presents a new type of multifunctional bioreactor, which is to provide cell tissue a mechanical environment which is close to the real situation. This bioreactor is based on the concept of fatigue machine, add torsion module to compress and tension module, with new design of both loading device and culturing device by modern CAD technology. Driven by voice coil motor, step motor and a well designed mechanical structure, this machine has excellent controlling performance and no accumulated error, easy to adjust operating height, loading frequency, compressing stroke and torsioning angle. It has different loading modes, with compression or torsion separately, or providing compound load with both torsion and compression. With a delicate culturing device, the height and the limit of loading head is easy to adjust accordingly, it can also provide liquid environment during the loading process, which is closer to biological characteristics and physiological environment. After simple refit, it's also able to be used as a tension machine. This machine supplies different mechanical environment for biomechanics research to make related experiments more effective and accurate.
Solution of the practical problems of the ice engineering requires the data about the strength of the ice cover that depends upon its temperature. In most cases, the snow lies on the ice cover and the ice temperature ...
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Solution of the practical problems of the ice engineering requires the data about the strength of the ice cover that depends upon its temperature. In most cases, the snow lies on the ice cover and the ice temperature differs from the atmospheric air temperature. To reveal the correlation of the air temperature with temperature on interfaces air-snow and snow-ice, the known in the thermophysics solution of the problem of the heat transfer through the multilayer plate was applied. Derived solution connects the temperature of air and temperature on the snow-ice interface and satisfactory correlates with data of the field measurements of the temperature within snow layer and ice cover and ice thickness on the Heilongjiang (Amur) River. Results of investigation are recommended for the ice temperature evaluation in engineering practice.
Studies have shown that the morphology and function of living cells are greatly affected by the state of different high acceleration. Based on the centrifuge, we designed a centrifugal cell loading machine for the mec...
Studies have shown that the morphology and function of living cells are greatly affected by the state of different high acceleration. Based on the centrifuge, we designed a centrifugal cell loading machine for the mechanical biology of cells under high acceleration loading. For the machine, the feasibility of the experiment was studied by means of constant acceleration or variable acceleration loading in the Petri dish fixture and/or culture flask. Here we analyzed the distribution of the acceleration of the cells with the change of position and size of the culturing device quantitatively. It is obtained that Petri dish fixture and/or culture flask can be used for constant acceleration loading by experiments; the centripetal acceleration of the adherent cells increases with the increase of the distance between the rotor center of the centrifuge and the fixture of the Petri dish and the size of the fixture. It achieves the idea that the general biology laboratory can conduct the study of mechanical biology at high acceleration. It also provides a basis for more accurate study of the law of high acceleration on mechanobiology of cells.
We propose a novel two-dimensional photonic crystal structure consisting of two line defect waveguides and a cavity to realize mode conversion based on the coupling effect. The W1/cavity/W2 structure breaks the spatia...
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We propose a novel two-dimensional photonic crystal structure consisting of two line defect waveguides and a cavity to realize mode conversion based on the coupling effect. The W1/cavity/W2 structure breaks the spatial symmetry and successfully converts the even(odd) mode to the odd(even) mode in the W2 waveguide during the forward(backward)transmission. When considering the incidence of only the even mode, the optical diode effect emerges and achieves approximate 35 d B unidirectionality at the resonant frequency. Moreover, owing to the narrow bandpass feature and the flexibility of the tuning cavity, utilization of the proposed structure as a wavelength filter is demonstrated in a device with a Y-branch splitter. Here, we provide a heuristic design for a mode converter, optical diode, and wavelength filter derived from the coupling effect between a cavity and adjacent waveguides, and expect that the proposed structure can be applied as a building block in future all-optical integrated circuits.
A comparative study of two over-constrained 2-RPU+SPR parallel manipulators (PM) is studied in terms of workspace and transmission performance in this paper. The two 2-RPU+SPR PMs have identical kinematics limbs, but ...
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ISBN:
(纸本)9781467384155
A comparative study of two over-constrained 2-RPU+SPR parallel manipulators (PM) is studied in terms of workspace and transmission performance in this paper. The two 2-RPU+SPR PMs have identical kinematics limbs, but some differences exist in terms of the joints distribution. The kinematics, the workspace and the transmission performance are studied and simulation examples are presented to demonstrate the differences between the two PMs. This study provides insights into the two parallel manipulators with identical limbs but with different joints distribution.
With the deepening of the Marine development, underwater constructing often need to use the ROV. In order to verify the construction scheme, ensuring construction efficiency, the staff will use ROV or Dummy ROV on lan...
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With the deepening of the Marine development, underwater constructing often need to use the ROV. In order to verify the construction scheme, ensuring construction efficiency, the staff will use ROV or Dummy ROV on land to simulate construction. As the main body of the ROV, the manipulator is the execution part of the system. It is the core of the whole system;all of the drive and control are around it. It references the mature underwater manipulator, and draw lessons from the domestic manipulator design experience. The design adopts electric drive, and the joints torque were calculated and simulated by the Solid Works motion analysis software.
Research the depth of 3000 m Work-Class ROV as mock object and develop a ROV for land test. This device is set three lifting point in the top. The rope connecting the front two lifting point is fixed, the rope connect...
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Research the depth of 3000 m Work-Class ROV as mock object and develop a ROV for land test. This device is set three lifting point in the top. The rope connecting the front two lifting point is fixed, the rope connecting the rear lifting point change the length by motor. All of those lifting point are in order to achieve the function of forerake and hypsokinesis. The Dummy ROV can displace the real ROV to simulate the land construction, improve the efficiency of ocean construction and reduce the cost of experiment.
Flow control valve generally consists of constant pressure difference reducing valve and throttle *** it works under the condition of high differential pressure and flow, the pressure loss of reducing valve in-stalled...
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Flow control valve generally consists of constant pressure difference reducing valve and throttle *** it works under the condition of high differential pressure and flow, the pressure loss of reducing valve in-stalled in main loop will get increased and the hydraulic oil temperature will be increased as well. A digital pilotflow control valve is studied in this paper. The main stage is a cartridge valve based on the flow amplifying princi-ple. The pilot stage is digital flow control valve which consists of digital valve and constant pressure difference re-ducing valve. The digital valve controlled by PWM signal has some characteristics such as less throttling loss andgood repeatability. The high pressure loss and hydraulic oil temperature will be effectively reduced by using con-stant pressure difference reducing valve in the small flow pilot circuit. Through theoretical derivation and simula-tion research, the feasibility of this valve is verified, and some conclusions are drawn for the relationships betweenthe performance and structure parameters, which provides theoretical basis for their design.
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