Decoupling control for a three-axis inertially stabilized platform used for aerial remote sensing

Abstract

A three-axis inertially stabilized platform (ISP) is an important component in an aerial remote sensing system, used for isolating the influences of various disturbances on imaging sensors. In order to deal with the coupling torques and improve the control precision of the ISP, a decoupling control method based on feedforward compensation is proposed in this paper. Firstly, the kinematic and dynamic model of three-axis ISP is developed by using a Lagrange equation. Then, the coupling effects among the three gimbals and base are analysed. Depending on the analysis of the model, the major coupling components are obtained and the dynamic model is simplified. Finally, a decoupling controller based on the feedforward compensation method is designed and applied to the ISP control system. Simulation and experimental results show that the stability and precision of the ISP are effectively improved.

Control Parameters Optimization Based on Co-Simulation of a Mechatronic System for an UA-Based Two-Axis Inertially Stabilized Platform

“…Generally, an aerial remote sensing system consists of four main components [20,21], i.e. , a multi-axis ISP, an imaging sensor, a position and orientation system (POS) and the aircraft vehicle.…”

“…We can see that the ISP consists of two gimbals, which are an azimuth gimbal (A-gimbal) and a pitch gimbal (P-gimbal) [20]. The P-gimbal is assembled on the A-gimbal and can rotate around the Y p axis.…”

“…According to references [20,21], the traditional Newton-Euler method is used to model the two-axis ISP in this paper. The basic Newton-Euler equation for a rotational rigid body is described by $\sum \mathit{M}=J\dot{\omega }+\mathit{\omega }\times J\omega$ where ∑M is the resultant moment of force applied to a rigid body, J is the inertia moment.…”

A Novel Separated Position and Orientation System Integrated with Inertially Stabilized Platform

“…Nowadays, common remote sensing system is composed of imaging payloads, position and orientation system (POS), and inertially stabilized platform (ISP). The imaging payloads are mounted on azimuth gimbal of the ISP system, and the POS consists of three gyros and three accelerometers are usually fixed on the imaging payloads so that the motion parameters of the imaging payloads can be measured by POS directly [6][7][8]. (It is called "centralized POS" below.…”

Experimental Validation of a Compound Control Scheme for a Two-Axis Inertially Stabilized Platform with Multi-Sensors in an Unmanned Helicopter-Based Airborne Power Line Inspection System

“…Besides, with the help of a two-axis ISP, the sensors’ LOS can track the lines and remain steady all along by rejecting various disturbing torques, such as vibration, air turbulence, wind gusts and so on. Therefore, there is much interest among researchers to investigate control methods with higher accuracy and stability by rejecting various disturbances [13]. In [12], a feedforward scheme for a two-axis ISP to reject a periodic disturbing torque acting on the payload due to static mass unbalance is reported.…”