Zhenwei Wu

Bio: Zhenwei Wu is an academic researcher from Shenyang Institute of Automation. The author has contributed to research in topics: Robot & Humanoid robot. The author has an hindex of 7, co-authored 28 publications receiving 145 citations. Previous affiliations of Zhenwei Wu include Chinese Academy of Sciences.

Rotorcraft UAV actuator failure estimation with KF-based adaptive UKF algorithm

Abstract: A new adaptive Unscented Kalman Filter (UKF) algorithm for actuator failure estimation is proposed. The novel filter method with adaptability to statistical characteristic of noise is presented to improve the estimation accuracy of traditional UKF. The algorithm with the adaptability to statistical characteristic of noise, named Kalman Filter (KF) -based adaptive UKF, is proposed to improve the UKF performance. Such an adaptive mechanism is intended to compensate the lack of a prior knowledge. The asymptotic property of the adaptive UKF is discussed. The Actuator Healthy Coefficients (AHCs) is introduced to denote the actuator failure model while the adaptive UKF is employed for on-line estimation of both the flight states and the AHCs parameters of rotorcraft UAV (RUAV). Simulations are conducted using the model of SIA- Heli-90 RUAV of Shenyang Institute of Automation, CAS. The results are compared with those obtained by normal UKF to demonstrate the effectiveness and improvements of the adaptive UKF algorithm. Besides, we also compare this algorithm with the MIT-based one which we propose in previous research.

Flying robot control system semi-physical simulation platform

Abstract: The invention relates to a flying robot control system semi-physical simulation platform which comprises a flying robot flight posture display/visual scene display computer, a flying robot dynamic model simulation computer, a flying robot airborne control system, a radio remote controller and a flying robot ground monitoring computer. The flying robot control system semi-physical simulation platform can simultaneously on-line debug a software system, a hardware system and a control algorithm of a flying robot and draws near an actual working condition of the flying robot to the maximum degree. A simulation experiment can directly verify the correctness of control signals through an executing steering gear of the flying robot airborne control system. The flying robot flight posture display/visual scene display computer can assist in verifying the actual working condition of the flying robot and the correctness of the control signals. The flying robot control system semi-physical simulation platform has stronger generality, stronger systematicness, stronger operability and stronger displaying performance and can be conveniently used in semi-physical simulation experiments of various flying robots. Repeated design of the flying robot control system is avoided, and test work of new function extension of the flying robot control system is greatly simplified.

Dynamic Stability Analyses Based on ZMP of a Wheel-based Humanoid Robot

Abstract: For wheel-based humanoid robot, the dynamic stability is also an important question just like for biped robot. This paper unites the new recursive Newton-Euler method for dynamic modeling and the ZMP concept and then obtains the ZMP model of the robot. The merit of this model is that it is a function of the position, velocity and acceleration of joints in joint space and easier to realize realtime control due to less calculation. Calculation and simulation show that the waist motion takes the main effect on the dynamic stability of the robot. Using the compensation of motion of the waist, the robot can realize dynamic motion. This paper also presents the concepts of the valid stable region and stable degree for the wheel-based robot.

Aerial photo camera and video camera controller applied to electric transmission line routing inspection

Abstract: The invention relates to an onboard aerial photo cradle head camera and video camera controller, in particular to an aerial photo controller for enabling an unmanned aerial vehicle ground control system to complete camera status checkout, shutter controlling and video camera zooming functions by a camera and video camera control interface The cradle head aerial photo controller for controlling a camera and a video camera is carried in an unmanned aerial vehicle cradle head, the cradle head aerial photo controller is respectively connected with a single lens reflex camera shutter and a high definition video camera local area network chip (LANC) interface through a camera interface and a video camera interface and connected with an unmanned aerial vehicle flight control system through a serial communication interface, and control commands of the cradle head aerial photo controller are integrated into a data link between the unmanned aerial vehicle flight control system and the unmanned aerial vehicle ground control system The controller has the advantages that the remote control function of the cradle head camera and video camera is achieved by the aid of serial communication of a cradle head module and a flight controller, and effects of application to unmanned aerial vehicle electricity line patrol, seismic resistance, combating floods, disaster-relief works and aerial photo are improved

Multiple obstacles avoidance for mobile robot in unstructured environments

Abstract: This paper focuses on multiple obstacles avoidance for mobile robot and presents novel obstacle avoidance maneuvers mainly by defining degree of risk and using fuzzy method. The methods are based on the relative coordinates and acceleration space in unstructured environments, where there exist not only multiple static obstacles, but also multiple moving ones. The simulation results verify its validity.

Analysis of Recursive Stochastic Algorithms

Abstract: Recursive algorithms where random observations enter are studied in a fairly general framework. An important feature is that the observations may depend on previous ?outputs? of the algorithm. The considered class of algorithms contains, e.g., stochastic approximation algorithms, recursive identification algorithms, and algorithms for adaptive control of linear systems. It is shown how a deterministic differential equation can be associated with the algorithm. Problems like convergence with probality one, possible convergence points and asymptotic behavior of the algorithm can all be studied in terms of this differential equation. Theorems stating the precise relationships between the differential equation and the algorithm are given as well as examples of applications of the results to problems in identification and adaptive control.

Development of advanced FDD and FTC techniques with application to an unmanned quadrotor helicopter testbed

Abstract: As the first part, this paper presents an overview on the existing works on fault detection and diagnosis (FDD) and fault-tolerant control (FTC) for unmanned rotorcraft systems. Considered faults include actuator and sensor faults for single and multi-rotor systems. As the second part, several FDD and FTC techniques developed recently at the Networked Autonomous Vehicles Lab of Concordia University are detailed along with experimental application to a unique and newly developed quadrotor helicopter testbed.

UAV Attitude Estimation Using Unscented Kalman Filter and TRIAD

Abstract: A main problem in autonomous vehicles in general, and in unmanned aerial vehicles (UAVs) in particular, is the determination of the attitude angles. A novel method to estimate these angles using off-the-shelf components is presented. This paper introduces an attitude heading reference system (AHRS) based on the unscented Kalman filter (UKF) using the three-axis attitude determination (TRIAD) algorithm as the observation model. The performance of the method is assessed through simulations and compared to an AHRS based on the extended Kalman filter (EKF). The paper presents field experiment results using a real fixed-wing UAV. The results show good real-time performance with low computational cost in a microcontroller.

Search and Rescue Rotary-Wing UAV and Its Application to the Lushan Ms 7.0 Earthquake

Abstract: Rapid search and rescue responses after earthquakes or in postseismic evaluation tend to be extremely difficult. To solve this problem, we summarized the requirements of search and rescue rotary-wing unmanned aerial vehicle SR-RUAV systems according to related works, manual earthquake search and rescue, and our knowledge to guide our research works. Based on these requirements, a series of research and technical works have been conducted to present an efficient SR-RUAV system. To help rescue teams locate interested areas quickly, a collapsed-building detecting approach that integrates low-altitude statistical image processing methods was proposed, which can increase survival rates by detecting collapsed buildings in a timely manner. The entire SR-RUAV system was illustrated by simulated earthquake response experiments in the China National Training Base for Search and Rescue CNTBSR from 2008 to 2010. On April 20, 2013, Lushan China experienced a disastrous earthquake magnitude 7.0. Because of the distribution of buildings in the rural areas, it was impossible to implement a rapid search and postseismic evaluation via ground searching. We provided our SR-RUAV to the Chinese International Search and Rescue Team CISAR and accurately detected collapsed buildings for ground rescue guidance at low altitudes. This system was significantly improved with respect to its searching/planning strategy and vision-based evaluation in different environments based on the lessons learned from actual missions after the earthquake. The SR-RUAV has proved to be applicable and time saving. The physical structure, searching and planning strategy, image-processing algorithm, and improvements in real missions are described in detail in this study.

Uav flight display

Abstract: Methods, systems, and devices are provided for displaying flight information related to a UAV. The UAV may carry a payload via a carrier that may permit the payload to move relative to the UAV. UAV related information including UAV state information and payload state information can be provided to a remote display terminal. The UAV state information can include position information as well as attitude information of the UAV. The payload state information can include attitude information of the payload relative to the UAV. The remote display terminal can be configured to simultaneously display the UAV state information and the payload state information so as to provide the user with an intuitive, comprehensive, yet efficient user interface.