The safety and reliability of robots are very important for the inspection in a long-distance pipeline used for the oil and gas transportation. In this paper, the long-distance pipeline pig and robots (LDPPRs) are classified into two categories, which are velocity-uncontrollable type and velocity-controllable type. Among them, the velocity control of velocity-controllable LDPPR has three ways, which are friction resistance, driving force, and self-running. Meanwhile, the mechanical models of the motion of the LDPPRs are classified into the dynamic model of the velocity-uncontrollable LDPPRs, velocity-controllable LDPPRs, and vibration, and the contact mechanics model between the rubber barrel and the pipe wall. In addition, the anti-stuck technologies, the inspection technologies, and the location technologies are investigated and analyzed. Thus, the purpose of this review is to provide a concise reference for the development and research directions, as well as the design of the LDPPRs.

In this paper, an efficient method for human facial expression recognition is presented based on LBP descriptor. Firstly, the face normalization is employed in order to improve the efficiencies of extracting facial features. Then, the feature blocks which mainly contain the eyes and mouth were obtained, and each feature block image was divided into several overlapping sub-regions equally to extract LBP histograms. After that, the PCA method is used to learn the structure of the expression in the LBP feature space. Finally, the recognition experiment is conducted on the JAFFE facial expression database by using the nearest neighbor classifier. Experimental result shows competitive performance.

The sealing performance will directly affect the operation of downhole robot under HTHP condition. Traditional analysis methods of sealing performance are that the temperature and pressure is loaded respectively. This can not really evaluate the sealing performance. Besides, the simulation process is: Step 1: pre-compress O-ring to produce contact force. According to the contact pressure, select the compression ratio to calculate the displacement of the slip ring. Step 2: load fluid pressure on the O-ring. This simulation method is to directly load pressure on the undeformed O-ring. However, the O-ring will deform after pre-compression. Therefore, this simulation method is not accurate. In order to make the simulation data more accurate, calculate the data of shape, stress, and strain of O-ring caused by pre-compression caused by assembly. Then, import the deformation body containing the real data of shape, stress, and strain into a new model. On the basis, establish the numerical simulation model of piston, piston guide rod, O-ring, and FTS-ring with HTHP loads is. Finally, calculate and analyze. When the compression ratio of the O-ring is about 14%, the sealing performance is good. What’s more, the distribution of contact stress and Von Mises of the O-ring at 8.3 mm/s of motion speed are analyzed. The results show that the foot shaped combined sealing structure can keep a good dynamic sealing performance under HTHP condition. This paper provides a theoretical basis for the analysis of the dynamic sealing performance by using HTHP coupling method. In the analysis of sealing performance: the hydraulic pressure is loaded to the real model with the real shape, stress, and strain produced by the O-ring assembly. This can more accurately evaluate the sealing performance under HTHP condition. It also provides a reference for the dynamic sealing structure design of downhole tools.