Zebo Zhou

University of Electronic Science and Technology of China | UESTC · School of Aeronautics and Astronautics

In kinematic Global Navigation Satellite Systems (GNSS) navigation, the Kalman Filter (KF) solution relies, to a great extent, on the quality of the dynamic model that describes the moving object's motion behaviour. However, it is rather difficult to establish a precise dynamic model that only connects the previous state and the current state, sinc...

The conventional dynamic model in the Kalman filtering-based GNSS navigation usually contains the state information of only one previous epoch, which can hardly reflect the real complex dynamic characteristics of motion behaviors. To improve the adaptability and accuracy of GNSS applications, a window-based polynomial fitting method is used to cons...

Carrier-phase-smoothed code (CPSC), i.e., smoothing of the code using carrier phases, has widely been used to reduce the code noise in GNSS applications. However, the efficiency of CPSC suffers significantly from cycle slips, interruptions and jitters. The GNSS Doppler, as an instantaneous measurement, is robust and immune to cycle slips and proven...

All conventional Kalman filtering methods depend to a great extent on dynamic models for describing the motion state of vehicle. However, low-cost GPS navigation systems do not provide velocity and acceleration measurements to construct dynamic models. Therefore, it is rather difficult to establish reasonable dynamic models. A windowing-recursive a...

Constraints can provide additional aids to a multi-sensor integrated navigation system and hence can increase accuracy of the solution and enhance reliability of the system. To integrate the constraints with the data from the sensors, the traditional integration Kalman filter (IKF) needs to be reconstructed. A new algorithm, the so-called constrain...

In the era of 5G communication, removing interference sources that affect communication is a resource-intensive task. The rapid development of computer vision has enabled unmanned aerial vehicles to perform various high-altitude detection tasks. Because the field of object detection for antenna interference sources has not been fully explored, this...

This paper proposes an adaptive Kalman filtering method with uncertain system noises based on variance component estimation (VCE) to adaptively tune the variances of system noises, i.e. process and measurement noises. A unified system noises contained model is constructed for estimating the variance components of both process and measurement noises...

The objective of this paper is to propose an energy-aware and gait corrected pedestrian dead reckoning (PDR) approach using foot-mounted magnetic, angular rate and gravity (MARG) sensors. Compared with existing algorithms of PDR, the proposed method aims to solve three main problems for real pedestrian applications. First, to avoid limitations of o...

In this paper, the Lasso formulation of the Wahba's problem is studied for spacecraft attitude determination problem from vector observations. This problem is designed in order to make the attitude solution more regularized and robust. The analytical quaternion solution is derived and is proven to be more continuous than results from previous Wahba...

Purpose – Autonomous orbit determination using geomagnetic measurements is an important backup technique for safe spacecraft navigation with a mere magnetometer. The geomagnetic model is employed for the state estimation of orbit elements but this model is highly nonlinear. Therefore, many efforts have been paid to developing nonlinear filters based...

This paper proposes a novel quaternion-based attitude estimation method for land-vehicle applications by fusing the low-cost magnetic, angular rate, and gravity (MARG) sensors and global navigation satellite systems measured velocity (GNSS-V). A structure of three-layer cascaded indirect Kalman filter (IKF) is devised to minimize the interactions o...

The rotary INS (inertial navigation system) has been applied to compensate the navigation errors of the MEMS (micro-electro-mechanical-systems) INS recently. In such system, the PVA (position, velocity, and attitude) errors can be compensated through IMU (inertial measurement unit) carouseling. However, the navigation errors are only partially comp...

Wireless sensor networks (WSNs) have become one of the core technologies of the internet of things (IoT) system. They are information generation and acquisition systems used by the IoT to sense and identify the surrounding environment. They are also sensor technology, embedding computing technology, communication technology and important product in...

This paper proposes a novel fast deterministic quaternion attitude determination method for accelerometer and magnetometer combination (AMC). After taking insight to the attitude determination theory, an important relationship between the sensor outputs and the magnetometer's reference vector is successfully derived. Based on the relationship, the...

For visually aided industrial robots, the transformation between the mounted visual information system and the end-effector must be calibrated prior to the practical use. However, during the data acquisition stage, measurement uncertainties will lead to inevitable mismatched data. This paper proposes a novel correspondence matching method for the h...

The logical representation and analyses of biological systems provide us with valuable insights. Inherent fluctuations play an important role in the long-term behaviors of biological systems. In this work, we mainly investigate the effects of function perturbations that might contribute to the development of effective therapies. We propose a stocha...

3D registration has always been performed invoking singular value decomposition (SVD) or eigenvalue decomposition (EIG) in real engineering practices. However, these numerical algorithms suffer from uncertainty of convergence in many cases. A novel fast symbolic solution is proposed in this paper by following our recent publication in this journal....

This is a correction to the linked paper.

Focusing on generalized sensor combinations, this paper deals with attitude estimation problem using a linear complementary filter. The quaternion observation model is obtained via a gradient descent algorithm (GDA). An additive measurement model is then established according to derived results. The filter is named as the generalized complementary...

This paper focuses on the approach to attitude estimation. When describing the attitude of a dynamic object, the quaternion has a better numerical continuity and stability compared with other conventional Euler angles’ methods. However, acceleration observation vector has a nonlinear relation to attitude quaternion and as a result, the representati...

In the past several years, there have been several representative attitude determination methods developed using derivative-based optimization algorithms. Optimization techniques e.g. gradient-descent algorithm (GDA), Gauss-Newton algorithm (GNA), Levenberg-Marquadt algorithm (LMA) suffer from local optimum in real engineering practices. A brief di...

In this paper, the Lasso formulation of the Wahba's problem is studied for spacecraft attitude determination problem from vector observations. The Lasso Wahba's problem is designed in order to make the attitude solution more regularized and robust. The analytical quaternion solution is derived and is proven to be more continuous than results from p...

In micro air vehicles (MAVs), a magnetometer is usually employed for heading estimation. However, in real flight campaigns the magnetometer can easily suffer interference from external magnetic disturbances. In this paper, a simple novel method is proposed to conduct real-time calibration of the magnetometer subject to external disturbances with th...

In this paper, we develop a foot‐mounted pedestrian navigation system prototype with the emphasis on distance measuring with an inertial measurement unit (IMU) which implies the characteristics of pedestrian gait cycle and thus can be used as a crucial step indicator for distance calculation. Conventional methods for step detection and step length...

A super fast attitude solution is obtained for consumer electronics accelerometer-magnetometer combination. The quaternion parameterizing the orientation is analytically derived from a least-square optimization that maintains very simple form. Like previously developed approaches, this algorithm does not require predetermined magnetometer reference...

In the past several years, there have been several representative attitude determination methods developed using derivative-based optimization algorithms. Optimization techniques e.g. gradient-descent algorithm (GDA), Gauss-Newton algorithm (GNA), Levenberg-Marquadt algorithm (LMA) suffer from local optimum in real engineering practices. A brief di...

Asynchronous multi-sensor systems have been widely equipped on various host platforms to meet the requirements of modern navigation campaigns. However, existing asynchronous fusion algorithms are not efficient in many challenged environments, due to limitations of communication condition, out-of-sequence observation and computation affordance. To s...

Attitude estimation from vector observations is widely employed in aerospace applications for accurate integrated navigation using solutions to Wahba's problem. Wahba's solutions are practical but may corrupt facing critical cases in the presence of almost collinear reference vector measurements, which is inevitable in robotic applications with red...

A novel solution is obtained to solve the rigid 3D registration problem, motivated by previous eigen-decomposition approaches. Different from existing solvers, the proposed algorithm does not require sophisticated matrix operations e.g. singular value decomposition or eigenvalue decomposition. Instead, the optimal eigenvector of the point cross-cov...

3D registration has always been performed invoking singular value decomposition (SVD) or eigenvalue decomposition (EIG) in real engineering practices. However, numerical algorithms suffer from uncertainty of convergence in many cases. A novel fast symbolic solution is proposed in this paper by following our recent publication in this journal. The e...

This paper deals with the integration problem for GNSS/INS integration navigation with the aid of vision sensor. The basic principle of visual navigation is presented and discussed. Given the triple sampling rates of sensors, we design a vision-aided GNSS/INS fusion method based on the sequential Kalman filter structure. The sequential Kalman filte...

In traditional indoor localization, fingerprint localization algorithm fully considers the influences of multipath signals and static obstacles but degrades in case of the changes of observation environment. Trilateration localization has the better robustness to the signal variations but its performance degrades for achieving a certain level of ac...

The integration of the Accelerometer and Magnetometer (AM) provides continuous, stable and accurate attitude information for land-vehicle navigation without magnetic distortion and external acceleration. However, magnetic disturbance and linear acceleration strongly degrade the overall system performance. As an important complement, the Global Navi...

Attitude determination using the accelerometer–magnetometer combination is basically an applied mathematical problem. Commonly, such attitude determination tasks should be accomplished with reference information of sensors, e.g. the magnetometer’s reference vector, from calibration processes. However, this piece of important information cannot be a...

As a key problem for multisensor attitude determination, Wahba's problem has been studied for almost 50 years. Different from existing methods, this paper presents a novel linear approach to solve this problem. We name the proposed method the fast linear attitude estimator (FLAE) because it is faster than known representative algorithms. The origin...

The inertial measurements imply the characteristics of pedestrian gait cycle and it can be used as a step indicator for the dead reckoning navigation. The parameters in conventional step detection methods need to be specified for different persons. However, it cannot well adapt to the general pedestrian applications. In this contribution, a foot-mo...

This paper solves the attitude determination problem based on a single sensor observation. The rotation equation is transformed into a quadratic quaternion form and is then derived to a linear matrix equation with pseudoinverse matrices. The analytic solutions to the equation are computed via elementary row operations. The solutions show that the a...

The Kalman filtering (KF) is optimal under the assumption that both process and observation noises are independent white Gaussian noise. However, this assumption is not always satisfied in real-world navigation campaigns. In this paper, two types of KF methods are investigated, i.e. augmented KF (AKF) and the second moment information based KF (SMI...

The accuracy of Kalman filtering (KF) relies on the quality of the observations as well as the dynamic model. However, the dynamic model is usually assumed to be invariant, which is not realistic in real global navigation satellite system (GNSS) navigation applications due to unexpected vehicular motion. A new algorithm is proposed to enhance the K...

This paper proposes a novel quaternion-based attitude estimator with magnetic, angular rate, and gravity (MARG) sensor arrays. A new structure of a fixed-gain complementary filter is designed fusing related sensors. To avoid using iterative algorithms, the accelerometer-based attitude determination is transformed into a linear system. Stable soluti...

An improvement of the attitude difference method (ADM) to estimate deflections of the vertical (DOV) in real time is described in this paper. The ADM without offline processing estimates the DOV with a limited accuracy due to the response delay. The proposed model selection-based self-adaptive delay feedback (SDF) method takes the results of the AD...

The performance of navigation sensors may be seriously affected by the operating rotors of a drone. To address this kind of disturbance , a low-cost multisensor integrated navigation system was developed for a quadrotor aerial vehicle (QAV). The navigation board integrates a global positioning system (GPS) module, triaxial gyroscope, accelerometer,...

In the Kalman filtering applications, the conventional dynamic model which connects the states information of two consecutive epochs by state transition matrix is usually predefined and assumed to be invariant. Aiming to improve the adaptability and accuracy of dynamic model, we propose multiple historical states involved filtering algorithm. An au...

Kalman filtering (KF), in previous works, assumes that system noises are white Gaussian noises (WGN) and are uncorrelated with each other. This assumption, however, is not reasonable in real-world navigation applications. This paper dedicates to develop an optimal Kaman filtering navigation algorithm in the time-correlated contained dynamic system....

Zebo has received several awards from academic organizations in China and his research interests include GNSS navigation and positioning, GNSS/INS integration, multi-sensor fusion, and surveying data processing theory. Jianfeng Zhang is currently a postgraduate in the School of Aeronautic & Astronautics and Laboratory of Aerial Robotics, UESTC. He...

In modern navigation applications, Inertial Navigation System (INS) is attractive for integrating with Global Positioning System (GPS). Although traditional GPS/INS integrated systems can bridge the GPS gaps, the navigation capability is strongly dependent on the performances of standalone INS. As an important complementary, a new terrestrial, Radi...

Doppler measurement is popularly applied to estimate the vehicle's velocity in GPS navigation and its stochastic characteristics attach a great importance to the quality of velocity estimate. In this contribution, firstly a single differenced (SD) Doppler observation is established with the known velocity. Secondly, the precision of un-differenced...

A two-step method for estimating the stochastic model of GPS/Doppler integrated observation is proposed. Firstly, the robustly posterior estimation is introduced according to equivalent weight principle and carrier-to-noise ratio. Then, the variance of unit weight is estimated in a moving-window in real time by combining the forgetting factor and o...

Micro-Electro-Mechanical Sensor (MEMS) inertial navigation sensors (INS) and GPS are attractive technologies for low-cost navigation applications. In the loosely-coupled integration schemes, GPS provides the position and velocity for real-time correction of the inertial sensor errors as well as the navigation parameters of the MEMS-INS. As an effic...

Future three frequency GNSS does bring some benefits to higher success rate and reliability of rapid ambiguity resolution. Nevertheless, the existent three carrier ambiguity resolution methods cannot be competent to ambiguity resolution in the long-range scenario. In this contribution, the key to restricting ambiguity resolution is investigated by...

Starting from the common LAMBDA algorithm with baseline length constraint, a combined search method of ambiguity resolution is put forward, which enhances the success rate and reliability and ensures the validity and usability of the single epoch algorithm. The results of calculation of several groups of GPS data indicate that the single epoch algo...