UWB ( Ultra Wide Band) technology is a new indoor positioning technology which has been widely studied for its low power consumption， high positioning accuracy and strong penetration ability. In this paper， based on the TDOA ( time difference of arrival) measurement method， UWB tags are used to send signals to multiple base stations to obtain the time stamp difference between tags and each base station， and the movement position of the tag is solved in real time by the Chan algorithm. The “current” statistical model is established， the iterative process of Kalman filtering is improved by setting the threshold， and them the improved adaptive Kalman filter algorithm is used to eliminate the influence of non line of sight error and noise on TDOA location so that the indoor positioning accuracy of TDOA is more accurate. Experiments show that the TDOA positioning method based on adaptive Kalman filter has high accuracy. 

Aiming at the problems of low accuracy , poor anti interference ability , and poor stability of traditional indoor Kalman filter positioning algorithm in complex indoor environments, a weighted adaptive Kalman filtering ( WKF )time difference of arrival ( TDOA ) positioning algorithm, based on ultra- wideband ( UWB) is proposed.Firstly, establish a four- anchor ultra- bandwidth positioning system, intrduce wireless clock synchronization technology to eliminate dlock erors. Secondly，compensate the original data to reduce positioning error caused by human reflection and multipeath effect and other influencing factors. Then，recursively update the noise covariance and dynamically adjust the weights to enhance the stability of the filter. Finally , dynamic real- time positioning of moving target is realized. The results show that WKF-TDOA can reduce positioning errors caused by multipath effet，and achieve dynamic real- time high-precision positioning of moving targets. Compared with other existing positioning methods，the experimental results show that this method has higher precision and better robustness.

Impulse Radio Ultra-wideband (IR-UWB) is a newly emerged short range wireless technology which is quite different with traditional wireless techniques. It has attracted great intention by researchers from academy and industry, for its wide application in communication, precise ranging and positioning, detection, imaging and so on. Based on time difference of arrival (TDOA) method, indoor localization using UWB signals will be studied in this paper. Aiming at the difficult ies of anchor node synchronization for standard TDOA method, an improved TDOA method is proposed. Performance analysis and optimization of this method are made. The main contents of this paper are as follows:

As wireless devices become more and more integrated into our daily lives, people's demand for wireless network information is also increasing, such as location, time, temperature, direction, etc. where the location of people or objects is the most important. There is GPS positioning technology outdoors, which can basically achieve meter-level accuracy and can meet the needs of daily life. Therefore, the research on indoor positioning technology is more important. As a new technology in recent years, Ultra-Wide-Band (UWB) signals are widely used in indoor positioning systems due to their advantages of narrow pulse, large bandwidth, and high time resolution. This article aims to analyze the performance of different UWB-based positioning algorithms by analyzing UWB signals, and improve and optimize the errors generated by positioning and ranging. The main research contents of this article are as follows:

With the development of science and society, the requirement of people for location survice change from outdoor location and navigation to indoor location survice.GPS is a mature technology, but is not fit for indoor location because of the shield wall, so many indoor technology come out, such as UWB, Ultrasonic, WiFi and UHF-RFIDand so on.Ultra Wide Band (UWB) technology has strong penetrability, low power dissipation, multipath effect high-resolution, high security, high location accuracy andso on. So this paper delve into distance measurement and location algorithm based on UWB, and combine differential method in order to correct location coordinate, realisehigh-accuracy real time location of under-test tag in three-dimentional space.

With the development of intelligent manufacturing, various service-oriented indoor robots have brought great convenience to people's lives. The prerequisite for robots toachieve specific services is to be able to achieve autonomous and precise positioning. UWB technology is a pulse communication technology that uses extremely narrow pulse signals to transmit data. It has the characteristics of low cost, low power consumption and simple system transceiver structure. It has great advantages in the field of high-precision indoor positioning. Through the research of UWB technology, this subject designs an indoor robot positioning system based on UWB, which has the characteristics of high real-time, high precision and low complexity, and can meet the needs of indoor robot positioning. The research of indoor robot positioning system based on UWB mainly includes the design of ranging scheme, the simulation and realization of ranging and positioning algorithm, the design and driving of hardware system, the writing of upper computer code, and the verification of UWB indoor robot positioning platform. The work of this thesis is as follows:

Now the Global Positioning System (GPS) and Beidou Satellite Navigation System (BDS) these two kinds of outdoor positioning system technology is increasingly mature,But compared with the rapid development of modern outdoor positioning technology, the indoor positioning was not respected by people, the indoor positioning this research topicis also slowly walked into people's horizons. Compared with the outdoor environment, the indoor environment is more complex, and the application of the previous outdoorpositioning technology in the indoor environment is far from a good positioning effect. In recent years, Ultra Wide Band(UWB) technology has become one of the most popularresearch topics in indoor positioning field due to its advantages of strong anti-interference ability, high precision and low power consumption.