Wang Shuguo

Operation Principle of a Bend Enhanced Curvature Optical Fiber Sensor

A curvature optical fiber sensor is reported in this paper. The curvature measurement sensitivity is improved using bend enhanced method. The operation principle of this intensity modulate macro-bend curvature optical fiber sensor is proposed based on light scattering theory: the bend of sensitive zone brings about mode coupling and leads to the variation of surface scattering loss. The mathematic model of relationship among light loss, bending curvature, surface roughness and parameters of the fibers configuration is also presented

A new path-planning algorithm for mobile robot based on neural network

A new path-planning algorithm based on neural networks is proposed for mobile robots. The neural network is used in the algorithm to model the environment and calculate the collision energy function (CEF) which is the dominating term in the cost function. To implement the path-planning procedure, rather than calculating the minimum value of the cost function directly, a discrete method is used to approximate the minus gradient direction of the cost function in order to determine the motion tendency of the point set along the path. Finally, the performance and efficiency of the algorithm are estimated through computer simulation. The algorithm is very efficient in situations where real-time operation is required.

Theoretical and experimental study of the dynamic transient characteristics of a hydrostatic bearing

Abstract The transient characteristics of a hydrostatic bearing under a step load have been studied by considering the compressibility of oil (containing air bubbles). The characteristic equations of the bearing during the transient stage have been set up, the duration of the transient stage has been obtained and the effects of the main parameters of the bearing system on the transient characteristics have been analysed. This study provides a new theoretical basis for improving the dynamic support precision of high quality bearings.

A robot fuzzy motion planning approach in unknown environments

A fuzzy robot motion planning approach is proposed in unknown environments for three-degree industrial robots. The proposed planning system is composed of several separate fuzzy units, which control individually each manipulator joint. Each unit combines a repelling influence, which is related to the nearby obstacle, with the attracting influence produced by the final manipulator configuration, to generate actuating command for each link. Effectiveness of the proposed approach is verified through simulation.

Real-Time Sensor-Based Motion Planning for Robot Manipulators

In this paper, a sensor-based motion planning method for robot arm manipulators operating among unknown obstacles of arbitrary shape is presented. It can be applied to on-line collision avoidance with no prior knowledge of the obstacles. The sensitive skin is used to build a description of the robot’s surroundings. This approach is based on the configuration space but the construction of the C-obstacle surface is avoided. The motion planning algorithm consists of three phases. In each phase, the point automation moves along a specified plane, on which the mapping of the obstacles into configuration space can be simplified. Hence, the computation time is reduced and the algorithm can work in real time. The effectiveness of the proposed method is verified by a series of simulations.

Mobile robot control based on fuzzy behavior and robot safety body in unknown environment

Based on the analysis of unknown environment for mobile robot, a robot safety body, sensing body and logic body are put forward with the robot physical body together. An open fuzzy behavior-based control architecture is then proposed on the basis of robot safety body for mobile robots in complex and unstructured environments. Many sensors in various kinds are used to localize and navigate with fuzzification on target information, obstacle information and local terrain. Finally, lots of experiments of our mobile robot are carried out in many kinds of man-made complex environments, and the control architecture and the robot safety body with our robot is proved valid, which give a solid support for our further research for mobile robot in unknown environments.

Sensor-based motion planning for robot manipulators in unknown environments

This paper deals with sensor-based motion planning method for a robot arm manipulator operating among unknown obstacles of arbitrary shape. It can be applied to online collision avoidance with no prior knowledge of the obstacles. The sensitive skin is used to build a description of the robots surroundings. This approach is based on the configuration space but the construction of the C-obstacle surface is avoided. The point automation is confined on some planes with square grids in the C-space. A path searching algorithm based on the square grids is used to guide the automation maneuvering around the C-obstacles on the selected planes. To avoid the construction of the C-obstacle surface, the robot geometry model is expanded, and the static collision detection method is used. Hence, the computation time is reduced and the algorithm can work in real time. The effectiveness of the proposed method is verified by a series of simulations.

Dynamics and smooth trajectory planning of free floating space robot with zero-disturbance spacecraft attitude

The stability of the spacecraft attitude is very important to the normal work of solar cells and the communication between the system and earth. Therefore a work mode of free floating space robot (FFSR) with zero-disturbance spacecraft attitude is presented; the dynamic equation of FFSR with zero-disturbance spacecraft attitude is derived based on Lagrange method; the smooth and consecutive joint trajectories are designed by adopting a planning method of trigonometric function according to the boundary conditions; the time distribution method of smooth segments to aim at the optimization of joint torques is investigated. The simulation results validate the method proposed, and the outcome sets a good foundation for the motion planning and control of FFSR with zero-disturbance spacecraft attitude.

Signal Processing of Robotic Sensitive Skin Based on DSP+FPGA

Sensitive skin is a new perceptual system for robot. It is mainly used for real-time collision avoidance for robot in unknown environment. The sensor signal will be interfered by the around noises, and it is difficult to meet the requirement of accuracy, real time and stability of the system when using traditional signal processing method. In this paper a novel digital signal processing system based on DSP+FPGA is discussed. The fast Fourier transform (FFT) and periodogram is used for analyzing the signal, and some methods are taken to rectify errors from the limitation of the FFT. The simulation and experiment validate that this method can reduce the effect of noises for system, and can satisfy the real-time collision avoidance for robot

A study of simulation and collision detection techniques of flexible manufacturing cells

A flexible manufacturing cell (FMC) consists of a machining center, robots, transportation devices and computers. In order to enable such a complex cell to run normally, one should examine the kinematical relationship of the components of the devices in the cell, test the accuracy of positioning and working cycles, and find troubles. This paper describes ideas of simulation and collisions detection and avoidance in a flexible manufacturing cell. The techniques of modeling cell collision avoidance and task programming are discussed in the paper.<<ETX>>