Papers by Keyword: Pipe Robot

Abstract: Most of pipelines are installed under the ground, so maintaining is one of the most critical issue. Furthermore, their own locations are difficult to be identified because of its environment. For those reason, identifying the location of pipelines is widely under the research with in-pipe robots. Most methods estimate the heading direction of pipe robots as the axial direction of pipelines. However, more detail research about the axial directions of pipelines is necessary because the defined directions are not always aligned with the heading direction of pipe robot. Therefore, this paper described the estimating method of pipeline radius and its axial direction relative the robot. The relative direction and radius of a pipe are estimated from location of contact points which is determined based on geometry. Geometric equation contains highly nonlinear term, so those are obtained by the numerical form instead of closed form. The suggested method is verified by an experiment approach. Since the real relative axial direction is hard to detect, the slope of pipes are computed from estimated value and inertial measurement unit attached to the robot. Estimated radius and slope have some error in discrete curved pipe, but estimated values are well matched under straight pipes condition.

Abstract: Medium pressure type pipe robot speed fluctuation mechanism is studied. we consider that the causes of speed fluctuation are Frictional resistance mutations. Compression effect of Fluids medium and the reaction of robot speed. According to the different between the motion state of pipe robot and frictional resistance mutation trend, we make numerical simulation by using Matlab to determine the speed fluctuations law on different parameters.

Abstract: In order to establish a flexible squirm pipe robot’s mechanical model and find an appropriate method to improve its moving performance, the working qualifications and dynamic analysis of brake wheels are made. Proceed with the robot's moving mechanism, the squirm principle and mechanical qualifications of the robot’s brake wheels are analyzed, and the model of the robot’s traction is derived. Based on that, the prototype is made. Finally, the validity of the design and theories is verified by experiments.

Abstract: In order to improve the adaptability and moving stabilization of the flexible squirm robot in pipe, its key structures, including brake wheels, flexible spring axle and guide head, are optimized. For the new designed robot, its moving ability and trafficability in straight pipe and L-shape pipe are analyzed. Proceed with the robot's moving qualification, mechanical model of the robot in pipe is established and its squirming qualifications are proposed. Finally, a flexible squirm robot is developed to verify the validity of the proposed method.

Abstract: The examination of outer cylinder of pipes in steam generators is difficult to fulfill due to confined space. A robotic system has been developed to do the job. The robot contains a base, four rotary balls, a slide guide, two steppers, a DC motor, a positioning mechanism, a synchromesh belt mechanism, a longitudinal mobile platform, an extending and retracting mechanism, a rotary platform and a micro vehicle. The positioning mechanism can locate and fix the robot efficiently. The motion of the robot consists of longitudinal motion and transverse motion. The extending and retracting mechanism can push and pull the micro vehicle carrying a micro CMOS camera. The pose of the camera mounted on the movable platform of a micro 3-CSR parallel mechanism can be adjusted by 3 bias-two-way SMA actuators. The control system consists of two levels of computers. The user interface was developed with VB. Fuzzy control method is utilized to control the motion of the longitudinal mobile platform. Grey evaluation method is applied to evaluate the status of checked areas according to obtained images. Experiment results indicate that the robot has met the needs of examination.