An in-pipe robot must be able to adapt to the various geometric changes of pipes and have large enough load carrying capacity in order to move freely in industry pipe and drag heavy load. A novel in-pipe 3SPR/3RPS typ...
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An in-pipe robot must be able to adapt to the various geometric changes of pipes and have large enough load carrying capacity in order to move freely in industry pipe and drag heavy load. A novel in-pipe 3SPR/3RPS type parallel manipulator is proposed and its kinematics is analyzed in this paper. First, an in-pipe parallel manipulator with multi-foot is designed, and its principle and characteristics are explained. Second, the kinematics formulae are derived for solving the displacement, velocity and acceleration of foot mechanism and parallel manipulator. Third, the statics formulae are derived for solving the active force of the foot mechanism and the active/constrained forces of the parallel manipulator. Finally, an analytic example is given for solving kinematics and statics of the in-pipe parallel manipulator and analytic solutions are verified by simulation solution.
In this work, we investigate a state estimation problem for a full-car semi-active suspension system. To account for the complex calculation and optimization problems, a vehicle-to-cloud-to-vehicle (V2C2V) scheme is u...
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Task-dependent controllers widely used in exoskeletons track predefined trajectories, which overly constrain the volitional motion of individuals with remnant voluntary mobility. Energy shaping, on the other hand, pro...
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To improve the performance of fine polarization maintaining fiber (PMF) couplers, it is necessary to increase the detection accuracy of polarization axis. The mathematical model of panda PMF index is established, and ...
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To improve the performance of fine polarization maintaining fiber (PMF) couplers, it is necessary to increase the detection accuracy of polarization axis. The mathematical model of panda PMF index is established, and then the side view method is simulated. From the simulation results, the light is transmitted in the optical fiber and is focused on the other side, and the maximum light intensity of the fiber image is related to the rotation angle and the observation distance. When the observation distance is constant, the maximum value of light intensity changes periodically with the PMF rotation angle. When the observation plane is near the focused one of the transmitted light, the highest light intensity of optical image reaches the maximum value, which is the polarization axis detection parameter of PMF. Based on this, detection method which takes the maximum intensity as the feature is proposed. Combining the micro-vision technology, the polarization axis detection system for fine PMF is designed. The image sharpness function which can confirm the position of the detection plane is proposed. The experimental data are processed using the Fourier filtering method. By fitting the experiment data with the cubic spline method, the panda PMF polarization axis is determined. According to the experimental results, the repetitive detection error is 0.61°, which meets the requirements of PMF coupler manufacturing.
GPS/ODO fusion-based localization is always used for mobile robot in outdoor environment. This approach takes advantage of short-term accuracy of odometry measurement and the long-term correction by the GPS unit. Gene...
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ISBN:
(纸本)9781467389600
GPS/ODO fusion-based localization is always used for mobile robot in outdoor environment. This approach takes advantage of short-term accuracy of odometry measurement and the long-term correction by the GPS unit. Generally, to improve the localization accuracy, precise system model and sensor noise model are probed. In this paper, by taking the linear and nonlinear equality state constraints into the EKF-based fusion framework with the method of perfect measurement and estimate projection, the performance of fusion results can be greatly improved. The modeling process is introduced and two simulation cases have been conducted, which show the positioning accuracy of the mobile robot can be significantly improved after the introduction of the equivalent constraint. Theoretically, this implementation allows us to define additional adjustments to improve the overall behavior of the filter.
Wave propagation and diffusion in linear materials preserve local reciprocity in terms of a symmetric Green's function. For wave propagations, the relation between the fields entering and leaving a system is more ...
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Wave propagation and diffusion in linear materials preserve local reciprocity in terms of a symmetric Green's function. For wave propagations, the relation between the fields entering and leaving a system is more relevant than the detailed information about the fields inside it. In such cases, the global reciprocity of the scattering off a system through several ports is more important, which is defined as the symmetric transmission between the scattering channels. When a two-port system supports nonreciprocal (electromagnetic, acoustic) wave propagation, it is a (optical, phonon) diode directly following the definition. However, to date no concrete definition or discussion has been made on the global reciprocity of diffusive processes through a multiple-port system. It thus remains unclear what are the differences and relations between the three concepts, namely, local nonreciprocity, global nonreciprocity, and diode effect in diffusion. Here, we provide theoretical analysis on the frequency-domain Green's function and define the global reciprocity of heat diffusion through a two-port system, which has a different setup from that of a thermal diode. We further prove the equivalence between a heat transfer system with broken steady-state global reciprocity and a thermal diode, assuming no temperature-dependent heat generation. The validities of some typical mechanisms in breaking the diffusive reciprocity and making a thermal diode have been discussed. Our results set a general background for future studies on symmetric and asymmetric diffusive processes.
Robots are integrating into human society and become an important part. The robots and human must be considered as a whole system and the robots should be intelligent both in digital and physical like human to coopera...
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ISBN:
(数字)9781728158716
ISBN:
(纸本)9781728158723
Robots are integrating into human society and become an important part. The robots and human must be considered as a whole system and the robots should be intelligent both in digital and physical like human to cooperate and interact with human non-physically or physically. For improving the physical intelligence of the robot, a magnetorheological fluid actuator (MRA) is proposed and studied in this paper. A collision model and a speed peak force planning method are proposed and some experiments are conducted. It shows that the collision peak force of the MRA with external objects can be easily controlled to different levels by controlling the compliance of the MRA for safe physical interaction with human or some striking works like hammering a nail.
In the recent years haptic interfaces became a reliable solution in order to solve problems which arise when humans interact with the environment. If in the research area of the haptic interaction between human and en...
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In the recent years haptic interfaces became a reliable solution in order to solve problems which arise when humans interact with the environment. If in the research area of the haptic interaction between human and environment there are important researches, a innovative approach for the interaction between the robot and the environment using haptic interfaces and virtual projection method is presented in this paper. In order to control this interaction we used the Virtual Projection Method where haptic control interfaces of impedance and admittance will be embedded. The obtained results, validated by simulations assure stability, stiffness, high maneuverability and adaptability for rescue walking robots in order to move in disaster, dangerous and hazardous areas.
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