Wang Daobo

Bio: Wang Daobo is an academic researcher from Nanjing University. The author has contributed to research in topics: PID controller & Control theory. The author has an hindex of 2, co-authored 5 publications receiving 70 citations.

Nonlinear Flight Control Strategy for an Underactuated Quadrotor Aerial Robot

Abstract: This paper presents development of nonlinear model and nonlinear control strategy for a 6-DOF quadrotor aerial robot. The nonlinear model of quadrotor aerial robot is based on Newton-Euler formalism. Model derivation comprises determining equations of motion of the quadrotor in three dimensions and seeking to approximate actuation forces through modeling of the aerodynamic coefficients and electric motor dynamics. The derived model is dynamically unstable. Thus a nonlinear control strategy is implemented for the quadrotor. The control strategy includes feedback linearization for translational subsystem and backstepping based nonlinear controller for the rotational subsystem of quadrotor aerial robot. Nonlinear Backstepping control design is based on constructing Lyapunov function for closed loop system and guarantees stability and tracking performance through Lyapunov energy dissipation. Effectiveness of the control design scheme is shown through nonlinear simulations.

Multi-UAV Objective Assignment Using Hungarian Fusion Genetic Algorithm

Abstract: In the background of air combat, the situation between multiple unmanned aerial vehicle (multi-UAV) and objectives has a certain impact on the task assignment. In order to improve the efficiency of assignment and obtain the best assignment scheme during the process of performing tasks, this paper proposes a method to evaluate the situation at a certain time. This method is the basis for establishing a multi-UAV objective assignment model. For solving the model, this paper presents the Hungarian fusion Genetic Algorithm. It first uses the feasible solutions solved by the Hungarian algorithm as the elite individuals in the initial population of the genetic algorithm, and then uses the objective function in the assignment model as the fitness function to optimize the results. The algorithm solves the problem that the assignment result of the Hungarian algorithm is not unique, and optimizes the drawback that the traditional Genetic Algorithm is prone to fall into local optimum. The simulation verified the effectiveness of the situational assessment method and the improved algorithm.

Switched PID control of motor-load system

Abstract: The position control problem of motor-load system is considered, and switched PID controllers are designed for different reference input signals. A new PID design method is developed according to model-matching principle and the problem of PID controller design is converted into fitting problem of magnitude-phase curve for restricted frequency range, first, the second-order reference model is selected to achieve performance index, and then the parameters of PID controller are obtained by solving a group of equations. Further, the reset stabilization problem of switched PID control systems is investigated, and stability of switched PID control systems is guaranteed by using controller state reset technique.

A Global Robust Particle Swarm Optimization by Improving the Learning Strategy

Abstract: In consideration of stagnation phenomenon in the later phase of the particle swarm optimization (PSO) caused by diversity scarcity of particles, a new learning strategy for improving the global and local exploration capability of particle swarm optimization is proposed in the paper. The new learning strategy is inspired by the mass migration behaviors of animal swarms that each individual has the ability of keeping its inertia movement and learning from another randomly selected individual that is nearer to the destination. Therefore, in the modified PSO, both of the inertia weight and the learning rate coefficients in the velocity update formula are replaced by random sequences multiplied with positive constants, and each particle learns from a randomly selected particle which has better performance in stead of learning from the previous best positions of itself and the population. Comparison results with the basic PSO on the examination of some well-known benchmark functions show the perfective and robustness of the modified PSO.

Development of an equivalent-input-disturbance based altitude controller for sea-skimming unmanned aerial vehicles

Abstract: Unmanned aerial vehicles (UAVs) with sea-skimming capability are usually operated at a very low altitude, which require fast yet robust height controller to maintain the desired flight level in order to avoid the vehicle ditching into the sea. Due to the disturbance introduced by sea waves, the measured height information is often noisy and inaccurate, which cannot be directly used by the autopilot. To increase the robustness of the longitude autopilot with respect to unknown external disturbance, we present a novel equivalent-input-disturbance based controller, which enables real time disturbance rejection by considering the external disturbance as an equivalent signal applied to the input channel. Simulation results have shown that the proposed method outperforms the conventional PID based controller in the presence of sea wave disturbances.

Dynamic analysis and PID control for a quadrotor

Abstract: In order to analyze the dynamic characteristics and PID controller performance of a quadrotor, this paper firstly describes the architecture of the quadrotor and analyzes the dynamic model of it. Then, based on the classic scheme of PID control, this paper designs a controller, which aims to regulate the posture (position and orientation) of the 6 d.o.f. quadrotor. Thirdly, the dynamic model is implemented in Matlab/Simulink simulation, and the PID control parameters are obtained according to the simulation results. Finally, a quadrotor with PID controllers is designed and made. In order to do the experiment, a flying experiment for the quadrotor has been done. The results of flying experiment show that the PID controllers robustly stabilize the quadrotor.

Quadrotors and Accelerometers: State Estimation with an Improved Dynamic Model

Abstract: Results are presented that quantify how velocity and attitude estimates can benefit from an improvement to the traditional quadrotor dynamic model. The improved model allows accelerometer measurements, which are routinely available at high rates, to reduce an estimator's dependence on complex exteroceptive measurements, such as those obtained by an onboard camera or laser range finder.

Feedback control strategies for quadrotor-type aerial robots: a survey:

Abstract: Control of aerial robots is a popular research field as applications with different payloads lead to a variety of flight missions. Quadrotor-type unmanned systems are one such example considered in...

Control allocation for fault tolerant control of a VTOL octorotor

Abstract: For the fault tolerant control of an eight-rotor VTOL Unmanned Air Vehicle (UAV), a control allocation scheme is proposed. The eight-rotor configuration provides actuator redundancy to ensure safe operation under rotor/motor failures. A PD controller is used to generate total thrust and moment demands. A cascade inverse method of control allocation is proposed to allocate the controller commands to the actuators whilst ensuring that actuator saturation does not occur. If the vehicle is subjected to rotor failures, the scheme re-allocates the commands to maintain the vehicle stability and performance. Until actuator saturation occurs the response of the vehicle is the same when operating with all motors or fewer. The response of the vehicle to several combinations of complete actuator failures is investigated by simulation and it is shown that the proposed method is able to maintain control after failure of up to four actuators. The controller is invarient and the vehicle response to commands is identical until motor saturation occurs.

Quadrotors unmanned aerial vehicles: a review

Abstract: Quadrotors are Vertical Take-Off and Landing aerial vehicles with many potential applications ranging from mapping to supporting rescue operations. This paper aims to provide an overview on various works carried out on the quadrotor, from the perspective of control and dynamic modelling. Also in this paper, based on the information summarized from 160 researches available, different control targets and flight missions are analysed and classified, and according to it, a general flight mission map is introduced. In addition, history of advances in development of quadrotors and set-ups proposed when performing experimental researches on quadrotors is presented.