Research On Autonomous Homing Based On Parafoil And Air-dropped Robot System

Parafoil has a lot of applications in aircraft recovery and equipment delivery because of its perfect control and glide performance, which can greatly improve air-drop precision and quality. It is the first time that the parafoil and air-drop robot system is delivered into the disaster scene. The public safety and technology standards in the disaster reduction field can be upgraded by means of various probing sensors carried by robot. Operation of the parafoil and payload system is affected by the deflection of left and right parafoil brakes. The system turns left (right), while left (right) manipulating rope is pulled down by the motor. Through constantly motor control, the setting trajectory will be tracked. If there is no improper error correction used in the control system, precise autonomous homing cannot be achieved. Therefore, a key to autonomous homing of the parafoil and payload system is the control strategy. This paper investigates the kinematics model, path planning based on chaos particle swarm optimization, horizontal trajectory tracking control scheme. The main contents are as follows:(1) Dynamic features of parafoil and payload system depends on air-dropped quality and parafoil form. In the trajectory tracking, the six-degree-of-freedom nonlinear kinematics model can meet the simulation requirements. A simplified model is established, and then the model is applied for simulating a type of parafoil-payload system. The constant crosswind simulation environment is set, and the influence of the crosswind is analyzed. The parameters of turn and flare are obtained. It can provide the basic simulation for the validation of control algorithm and the theoretical basis for the practical control system.(2) The chaos particle swarm optimization is proposed to deal with path planning of parafoil and payload system. The controlled plant is three-degree-of-freedom parafoil and payload system. The non-uniform B-spline is adopted to characterize the control law and achieve the parameterized design variables. So the optimal control problem of trajectory planning is transformed into parameter optimization problem. Then the chaos particle swarm optimization is employed for optimization. The optimal controls are smooth, so the control rope can be manipulated easily by controlling motors. The method is not sensitive to initial position and easy to realize.The main purpose of the path optimization is to obtain trajectory characteristics and control law of autonomous homing. The homing trajectory will be more reasonable.(3) The dynamics of the parafoil and air-dropped are complicated, with nonlinearity and randomness. The horizontal trajectory tracking control scheme is proposed to meet the requirements of landing precision. The control scheme refers to the six degree-of-freedom nonlinear kinematics model of parafoil and payload system. The heading guidance is designed according to the cross track error. The heading controller devised based on adaptive generalized predictive control can control the deflection of left and right parafoil brakes. The feasibility and validity of the control scheme is confirmed in the simulation.(4) The heading controller is devised based on ADRC and control value is saturated to protect the system from peaking in the observer's transient response. The validity of the control algorithm is confirmed in the simulation. The results show that the controller design can achieve high precision on tracking control and has better dynamic performance than PD controller.