# Rotating Lorentz Force Magnetic Bearings' Dynamics Modeling and Adaptive Controller Design
## 2 Design of Lorentz Force Universal Magnetic Levitation Configuration  
### Seven-Degree-of-Freedom Universal Suspension Scheme  
The Lorentz force magnetic levitation universal stability platform is a seven-degree-of-freedom magnetic levitation mechanism made up of a load tank, a frame cabin, and a platform cabin, as well as two pairs of rotating Lorentz force magnetic bearings and pairs of linear and orthogonal Lorentz force bearings. The right-hand rule is used to establish the direction of the Z-axis, and the linear Lorentz force magnetic bearing controls the translational movement of the load chamber in the Y direction, as shown in Figure 1. Assuming the geometric center of the load tank serves as the origin for the coordinate system, the geometric centers of the load tank and the frame cabin are coincident. The active rotation axes of the load tank and the frame cabin are the Y- and X-axes, respectively, and the direction of the orthogonal Lorentz force magnetic bearing controls the translation and rotation of the load chamber in the X and Z directions. The payload tank is finally suspended in five degrees of freedom. To achieve a single-degree-of-freedom deflection, two sets of rotating Lorentz force magnetic bearings control the load chamber and frame compartment around their respective rotating axes. Among them, the inner RLFMB directs the rotation of the load compartment in the Y direction, while the outer RLFMB directs the rotation of the frame compartment in the X direction. Together, the two are able to universally deflect the load. The general layout of the universal stable platform for the Lorentz force is depicted in Figure 2.  
As can be seen in Figure 3, the load chamber's three degrees of freedom of X, Y, and Z translational magnetic levitation and rotation are controlled by orthogonal, linear Lorentz force magnetic bearings. Figure 1 shows that there is little space between the load tank and the frame compartment, which means that the load tank rotates in the same direction as the outside RLFMB control load compartment in the X and Z directions. The inner and outer RLFMB control how the load chamber and the frame compartment rotate along the Y- and Z-axes, and furthermore, ensure the maneuvering coverage and pointing stability of the load carried by the load compartment to the \(1\pi\) space. As a result, the five-degree-of-freedom movement controlled by orthogonal and linear magnetic bearings serves to keep the load chamber in the frame cabin with good magnetic levitation performance.  
Figure 1: RLFMB control load compartment/frame compartment deflection.  
Figure 2: Schematic diagram of the overall configuration of the universal stable platform.  
To accomplish a steady direction of movement of the load to the target, the Lorentz force magnetic levitation universal stabilization platform modifies the operating current of each magnetic bearing to manage its output force and angular moment. The computer calculates the magnitude of the pointing error while the target is in the load field of vision, and then it modifies the working current of each magnetic bearing to accomplish closed-loop control.