Shaorong Xie

Unmanned airships for emergency management

There are keen demands of robotic technologies in management of many kinds of emergencies. In this paper, we argue that unmanned airships present a unique potential in emergency management cycle, and their applications for surveillance, search and rescue, and communication are discussed. To make our lighter-than-air platform an autonomous airship with significant levels of autonomy for emergency management, the hardware infrastructure and software of the flight control system are designed and detailed. Based on a decoupled longitude and latitude dynamic model, the control architecture is developed, and a fuzzy control strategy is applied in mission path following problem. An application case of target searching using the autonomous airship is given and analyzed.

Robotic airship mission path-following control based on ANN and human operator’s skill

Robotic airships have numerous low-speed and low-altitude application potentials. Mission path following is one such application, which, however, presents an autonomy challenge. In this paper, a yawing controller, which is based on artificial neural network (ANN) and human operator skills, is proposed for mission path following of robotic airships. First, the path-following errors based on the operator’s point of view are discussed. Then, a data acquisition system is designed to collect the flight data under manual control, and the data are then processed and used for offline training and validation of a multilayer feed-forward neural network. Finally, the trained neural network is reconstructed in the flight control system for yawing control, and the experimental results confirm the effectiveness of this method. It is also shown that the ANN controller is robust even with wind disturbance.

A flight control and navigation system of a small size unmanned airship

Unmanned airships present an enormous potential for low-speed and low-altitude exploration applications. In order to develop a flight robot based on a small size unmanned remotely controlled airship, a flight and navigation system is presented in this paper. The hardware and software of the system are designed. As the kernel of the system, the flight control and navigation strategies are detailed. On the basis of the airship dynamic model, the architecture of the control system is presented, and the fuzzy controllers are employed and optimized using an improved genetic algorithm. Based on the airship model and the control and navigation strategies, the simulation studies of 3D path tracking problem are given and analyzed.

Biomimetic control of pan-tilt-zoom camera for visual tracking based-on an autonomous helicopter

A novel control strategy of pan-tilt-zoom camera is described. Because the active camera is mounted on a moving autonomous helicopter in visual tracking system, and the tracked object is moving at same time, and there exists the vibration influence of the helicopter, image stabilization becomes poor, and all pixels are running. Therefore, a biomimetic control strategy of on-board pan-tilt-zoom camera is presented. In this paper, the biomimetic oculomotor control model is obtained based on physiological neural path of eye movement control. In order to validate the functions of the biomimetic control model, simulation experiments were done under the same condition as the physiological experiments in physiological researches. Then the biomimetic controller of onboard pan-tilt-zoom camera is developed. The results of flight tracking experiments show that the biomimetic controller can compensate the deflection caused by the flight platform, and enhance the visual tracking system performance.

Development of cable maintenance robot for cable‐stayed bridges

Purpose – In order to replace the conventional human maintenance of cable‐stayed bridges, a robot is designed and constructed for tasks such as cleaning, painting and rust‐detecting.Design/methodology/approach – Adopting a modular approach, two kinds of climbing mechanisms, plus a painting mechanism and a rust‐detecting method are designed.Findings – A robot that can climb and maintain the cables of cable‐stayed bridges has been designed and constructed. It has been proved by experiment that the robot can overcome many disadvantages of conventional human bridge‐maintenance, and drastically improve efficiency, cost, and safety.Research limitations/implications – The robot is of industrial size, but a new mechanism requiring less installing time will be designed for the future.Practical implications – The robot has been applied to cables of the Nanpu Bridge and Xupu Bridge in Shanghai. More than 80 cable‐stayed bridges and six suspension bridges have been built or are being constructed across large rivers i...

Modeling of the UAV On-board Pan-tilt Control System Based on Biomimetic Eye

In this paper, oculomotor characteristics and form were analyzed, the three-dimensional oculomotor control system model of biomimetic eye was developed based on the oculomotor neural paths, then the model was applied to the UAV on-board pan-tilt control system in the ground moving target low-altitude tracking system to coordinately control UAV and the on-board pan-tilt camera, thus the on-board camera can track the ground moving target continuously, smoothly, clearly and stably like human eyes

A novel asymmetrical pitch system for a rotor micro air vehicle

Concerning to problems of the traditional machine pitch system for miniaturizing Micro Air Vehicles (MAVs), A novel asymmetrical pitch method is put forward in this paper. This novel method makes use of the deformation of an elasticity link to generate the blade pitch meeting the requirement of the MAV flight mode control. This new pitch mechanism has been verified by means of two experiments. One experiment measures blade pitch angle by a non-contact measurement using the high speed camera and image processing and the other experiment measures deformation of the elasticity link which is key part in asymmetrical pitch system based on strain gauge and rotating electrical connector. From relationship between blade pitch angles and the output torque of the main motor and deformation curves of the elasticity link, the pitch mechanism that the deformation will periodically change once with the rotor blade rounding a lap is proved.

Design of flight control system for a robotic blimp

Robotic blimps present an enormous potential for applications in low-speed and low-altitude exploration, surveillance, and monitoring, as well as telecommunication relay platforms. To make our lighter-than-air platform a robotic blimp with significant levels of autonomy, the decoupled longitude and latitude dynamic model are developed, and the hardware and software of the flight control system are designed. The onboard hardware consists of blimp state observer, actuators, MCU, etc. The software functions include signals processing, data filtering and fault tolerance, ground command execution, etc. Based on decoupled dynamic model, the control system architecture is presented, and navigation strategy for waypoint flight problem is discussed. The paper gives results of a flight experiment using the designed flight control system, and the results manifests that the system is applicable and initial machine intelligence of robotic blimp is achieved.

Detection and tracking of moving object in visual tracking from a low-altitude flying helicopter

In order to perform tracking a moving object, a vision-based tracking system mounted on a low-altitude flying unmanned helicopter is established. It is most important that the moving object must accurately be detected and tracked from dynamic scene. The multi-threshold segmentation algorithm with adaptive tolerance based on grey-level histogram is presented. And then the object dynamic clustering algorithm with double sub-windows is used in order to avoid the disturbance of other similar object. The motion region is segmented in the shade by several appended thresholds for different illuminance. The object centroid position can be obtained correctly through 2~3 iterations in the process of dynamic clustering. The pan and tilt head is controlled based on the warping distance of the object centroid. Its pace is adjusted according to the direction of the object moving. The system produces good tracking results at a frame rate of 15 fps. These algorithms and methods are available, and the system has a certain extent practicability.

Biomimetic Control of Pan-tilt-zoom Camera Mounted on an Autonomous Helicopter

This paper describes a novel control strategy of pan-tilt-zoom camera for tracking a ground moving object from an autonomous helicopter. Because the active camera is mounted on a moving helicopter, and the tracked object is moving at same time, and there exists the vibration influence of the helicopter, image stabilization becomes poor, and all pixels are running. Therefore, a biomimetic control strategy of on-board pan-tilt-zoom camera is presented. In this paper, the biomimetic oculomotor control model is obtained based on physiological neural path of eye movement control. In order to validate the functions of the biomimetic control model, simulation experiments were done under the same condition as the physiological experiments in physiological researches. Then the biomimetic controller of on-board pan-tilt-zoom camera is developed. The results of flight tracking experiments show that the biomimetic controller can compensate the deflection caused by the flight platform, and enhance the system performance.