力觉触觉再现技术及其应用研究

力觉确虫觉再现技术是近年来发展起来的一项新兴技术，在遥操作机器人、虚拟现实、医疗仿真、原形设计、纳米操作等很多领域中获得了相当广泛的应用。力觉／触觉再现接口是一种力反射设备，它可以使用户触摸、感觉、操作、创建和变换虚拟环境中仿真的虚拟3维物体。根据能量来源的方式，力觉确虫觉再现接日分为有源和无源两类。本论文针对有源力觉／触觉再现接口的动力学进行了分析，并以虚拟手术和机器人遥操作为背景，做了一些力觉／触觉再现技术的应用性研究工作。具体说来，本文主要进行了如下四项有创造和有价值的工作：（1)分析了有源力觉／触觉再现接口设计时所要考虑的几个基本问题，推导了力觉确虫觉再现接口的动力学模型。(2)以PHANTOM和GHOST SDK为开发平台，构造了一个虚拟仿真系统，研究实现力觉确虫觉再现接口涉及的几个基本问题。(3)以力觉／触觉再现接口PHANTOM为主端，全方位移动机器人M.BOT为从端建立了遥操作实验系统。提出了两种系统结构：位置给定系统和速度给定系统，并根据速度给定系统给出了具体设计。（4）遥操作实验研究。对于速度给定系统，给出了虚拟平面、虚拟障碍和虚拟墙实验。对位置给定系统与速度给定系统进行了对比分析。实验主要体现力觉／触觉再现技术对遥操作精确定位与避免碰撞的作用。

多波多分量地震资料走时近似方法的研究与应用

Compared with the conventional P wave, multi-component seismic data can markedly provide more information, thus improve the quality of reservoir evaluation like formation evaluation etc. With PS wave, better imaging result can be obtained especially in areas involved with gas chimney and high velocity formation. However, the signal-to-noise of multi-component seismic data is normally lower than that of the conventional P wave seismic data, while the frequency range of converted wave is always close to that of the surface wave which adds to the difficulty of removing surface wave. To realize common reflection point data stacking from extracted common conversion point data is a hard nut to crack. The s wave static correction of common receiver point PS wave data is not easy neither. In a word, the processing of multi-component seismic data is more complicated than P wave data. This paper shows some work that has been done, addressing those problems mentioned above. (1) Based on the AVO feature of converted wave, this paper has realized the velocity spectrum of converted waves by using Sarkar’s generalized semblance method taking into account of AVO factor in velocity analysis. (2)We achieve a method of smoothly offset division normal method.Firstly we scan the stacking velocities in different offset divisions for a t0, secondly obtain some hyperbolas using these stacking velocities, then get the travel time for every trace using these hyperbolas; in the end we interpolate the normal move out between two t0 for every trace. (3) Here realize a method of stepwise offset division normal moveout.It is similar to the method of smoothly offset division normal moveout.The main difference is using quadratic curve, sixth order curve or fraction curve to fit these hyperbolas. (4)In this paper, 4 types of travel time versus distance functions in inhomogeneous media whose velocity or slowness varies with depth and vertical travel time have been discussed and used to approximate reflection travel time. The errors of ray path and travel time based on those functions in four layered models were analyzed, and it has shown that effective results of NMO in synthetic or real data can be obtained. (5) The velocity model of converted PS-wave can be considered as that of P -wave based on the ghost source theory, thus the converted wave travel time can be approximated by calculation from 4 equivalent velocity functions: velocity or slowness vary linearly with depth or vertical travel time. Then combining with P wave velocity analysis, the converted wave data can be corrected directly to the P-wave vertical travel time. The improvements were shown in Normal Move out of converted waves with numerical examples and real data. (6) This paper introduces the methods to compute conversion point location in vertical inhomogeneous media based on linear functions of velocity or slowness versus depth or vertical travel time, and introduce three ways to choose appropriate equivalent velocity methods, which are velocity fitting, travel time approximation and semblance coefficient methods.

反射地震转换波成像方法研究

Multi-waves and multi-component get more and more attentions from oil industry. On the basis of existent research results, My research focuses on some key steps of OBC 4C datum processing. OBC datum must be preprocessed quite well for getting a good image. We show a flow chart of preprocess including attenuation of noise on multi-component datum、elimination ghost by summing P and Z and rotation of horizontal components. This is a good foundation for the coming steps about OBC processing. How to get exact converted point location and to analyze velocity are key points in processing reflection seismic converted wave data. This paper includes computing converted point location, analyzing velocity and nonhyperbolic moveout about converted waves. Anisotropic affects deeply the location of converted wave and the nonhyperbolic moveout. Supposed VTI, we research anisotropic effect on converted wave location and the moveout. Since Vp/Vs is important, we research the compute method of Vp/Vs from post-stack data and pre-stack data. It is a part of the paper that inversing anisotropic parameter by traveltime. Pre-stack time migration of converted wave is an focus, using common-offset Kirchhoff migration, we research the velocity model updating in anisotropic media. I have achieved the following results: 1) using continued Fractions, we proposed a new converted point approximate equation, when the offset is long enough ,the thomsen’s 2 order equation can’t approximate to the exact location of converted point, our equation is a good approximate for the exact location. 2) our new methods about scanning nonhyperbolic velocity and Vp/Vs can get a high quality energy spectrum. And the new moveout can fit the middle and long offset events. Processing the field data get a good result. 3) a new moveout equation, which have the same form as Alkhalifah’s long offset P wave moveout equation, have the same degree preciseness as thomsen’s moveout equation by testing model data. 4) using c as a function of the ratio offset to depth, we can uniform the Li’s and thomsen’s moveout equation in a same equation, the model test tell us choice the reasonable function C can improve the exact degree of Li’s and thomsen’s equation. 5) using traveltime inversion ,we can get anisotropic parameter, which can help to flat the large offset event and propose a model of anisotropic parameter which will useful for converted wave pre-stack time migration in anisotropic media. 6）using our pre-stack time migration method and flow, we can update the velocity model and anisotropic parameter model then get good image. Key words: OBC, Common converted Point (CCP), Nonhyperbolic moveout equation, Normal moveout correction, Velocity analysis, Anisotropic parameters inversion, Kirchhoff anisotropic pre-stack time migration, migration velocity model updating