Output feedback control with a nonlinear observer based forward kinematics solution of a Stewart platform
Output feedback control with a nonlinear observer based forward kinematics solution of a Stewart platform
复制标题
基于 Stewart 平台正向运动学解的非线性观测器的输出反馈控制
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
L. Fu
中科院分区：
文献类型：
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作者：
Sung;L. Fu
在六自由度移动平台的控制问题中，加速度计和倾斜传感器无法测量平台的位置和某些旋转角度。在没有全状态反馈的情况下，必须将逆运动学应用到控制方案中，以将期望的平台位置和方向转换为腿长。实际的控制目标变成控制个人腿的长度。为了实现输出反馈控制，采用非线性观测器估计系统的三轴平移和旋转状态，求解正运动学解。传统的Newton-Raphson等基于消去法的正解计算量大或过于复杂，难以在实时应用中实现。本文采用非线性观测器和滑模控制器直接控制平台的六个状态。验证了整个系统的稳定性，以保证控制误差收敛。
In the control issue of the 6-DOF moving platform, positions and some rotation angles of the platform can not be measured with accelerometers and tilt sensors. Without full state feedback, the inverse kinematics must be applied into the control scheme to convert the desired platform position and orientation to the leg lengths. The actual control goal becomes to control individual leg lengths. To achieve the output feedback control, the forward kinematics solution is solved by using a nonlinear observer designed to estimate the system states including 3-axes translations and rotations. The conventional forward kinematics solutions using Newton-Raphson and other elimination-based methods have too much computational burden or are too complex to take out in the real time applications. In this paper, the nonlinear observer and a sliding mode controller are used to control the six states of the platform directly. The stability of whole system is verified to ensure the control errors would converge.