KinectPV2 library for processing 下载地址：GitHub – ThomasLengeling/KinectPV2: Kinect4W 2.0 library for Processing
The Microsoft Kinect sensor is a peripheral device (designed for XBox and windows PCs) that functions much like a webcam. However, in addition to providing an RGB image, it also provides a depth map. Meaning for every pixel seen by the sensor, the Kinect measures distance from the sensor. This makes a variety of computer vision problems like background removal, blob detection, and more easy and fun!
The Kinect sensor itself only measures color and depth. However, once that information is on your computer, lots more can be done like “skeleton” tracking (i.e. detecting a model of a person and tracking his/her movements). To do skeleton tracking you’ll need to use Thomas Lengling’s windows-only Kinect v2 processing libray. However, if you’re on a Mac and all you want is raw data from the Kinect, you are in luck! This library uses libfreenect and libfreenect2 open source drivers to access that data for Mac OS X (windows support coming soon).
我按照网上的这个视频教程进行了制作。教程链接：四分钟学会无人机实景建模，无人机通用3D实景建模教程 – 西瓜视频 (ixigua.com)
打开ContextCapture Center Master，加载照片，按照教程制作。由于要计算几百张照片的各种信息，制作很花时间。
TouchDesigner 功能元件主要分为6大类：COMP, TOP, CHOP, SOP, DAT, MAT，对于不同方向的运用。比如TOP内的控制器主要用于处理图像及影像，而SOP内的控制器主要用于3D的处理。
TouchDesigner 现支持 Windows、Mac OS 两种系统。
Track switching for a magnetically levitated transportation system and method
Abstract A magnetically levitated transportation system employs permanent magnet rails along a guideway that interact with permanent magnets on a vehicle. The rails are optimized to reduce magnetic mass and cost of materials, while maximizing lift force. The vehicle is stabilized in the lateral and yaw directions with feedback controlled lateral control coils that interact with the permanent magnet rails on the guideway. A track switching structure employs permanent magnet rails that gradually widen along a segment of track and separate into two identical diverging rails. Feedback controlled lateral control coils in a moving vehicle stabilize that vehicle over one or the other pairs of diverging rails, as directed by a control computer, thereby causing the vehicle to continue along one path or the other, with no moving or active elements required in the track.
百度百科：Halbach Array一般指海尔贝克阵列，见 海尔贝克阵列_百度百科 (baidu.com)
海尔贝克阵列（Halbach Array）是一种磁体结构，是工程上的近似理想结构，目标是用最少量的磁体产生最强的磁场。1979 年，美国学者Klaus Halbach做电子加速实验时，发现了这种特殊的永磁铁结构，并逐步完善这种结构，最终形成了所谓的“Halbach”磁铁。
A Halbach array is a special arrangement of permanent magnets that augments the magnetic field on one side of the array while cancelling the field to near zero on the other side. This is achieved by having a spatially rotating pattern of magnetisation.
The rotating pattern of permanent magnets (on the front face; on the left, up, right, down) can be continued indefinitely and have the same effect. The effect of this arrangement is roughly similar to many horseshoe magnets placed adjacent to each other, with similar poles touching.
The effect was also discovered by John C. Mallinson in 1973, and these “one-sided flux” structures were initially described by him as a “curiosity”, although at the time he recognized from this discovery the potential for significant improvements in magnetic tape technology.
The advantages of one-sided flux distributions are twofold:
- The field is twice as large on the side on which the flux is confined (in the idealized case).
- There is no stray field produced (in the ideal case) on the opposite side. This helps with field confinement, usually a problem in the design of magnetic structures.
Although one-sided flux distributions may seem somewhat abstract, they have a surprising number of applications ranging from the refrigerator magnet through industrial applications such as the brushless DC motor, voice coils, magnetic drug targeting to high-tech applications such as wiggler magnets used in particle accelerators and free-electron lasers.
This device is also a key component of the Inductrack Maglev train and Inductrack rocket-launch system, wherein the Halbach array repels loops of wire that form the track after the train has been accelerated to a speed able to lift.
The simplest example of a one-sided flux magnet is a refrigerator magnet. These are usually composed of powdered ferrite in a binder such as plastic or rubber. The extruded magnet is exposed to a rotating field giving the ferrite particles in the magnetic compound a magnetization resulting in a one-sided flux distribution. This distribution increases the holding force of the magnet when placed on a permeable surface, compared to the holding force from, say, a uniform magnetization of the magnetic compound.
Scaling up this design and adding a top sheet gives a wiggler magnet, used in synchrotrons and free-electron lasers. Wiggler magnets wiggle, or oscillate, an electron beam perpendicular to the magnetic field. As the electrons are undergoing acceleration, they radiate electromagnetic energy in their flight direction, and as they interact with the light already emitted, photons along its line are emitted in phase, resulting in a “laser-like” monochromatic and coherent beam.
The design shown above is usually known as a Halbach wiggler. The magnetization vectors in the magnetized sheets rotate in the opposite senses to each other; above, the top sheet\\’s magnetization vector rotates clockwise, and the bottom sheet\\’s magnetization vector rotates counter-clockwise. This design is chosen so that the x components of the magnetic fields from the sheets cancel, and the y components reinforce, so that the field is given by
where k is the wavenumber of the magnetic sheet given by the spacing between magnetic blocks with the same magnetization vector.
These cylindrical structures are used in devices such as brushless AC motors, magnetic couplings and high-field cylinders. Both brushless motors and coupling devices use multipole field arrangements:
- Brushless motors typically use cylindrical designs in which all the flux is confined to the centre of the bore (such as k = 4 above, a 6-pole rotor) with the AC coils also contained within the bore. Such self-shielding motors designs are more efficient and produce higher torque than conventional motor designs.
- Magnetic-coupling devices transmit torque through magnetically transparent barriers (that is, the barrier is non-magnetic or is magnetic but not affected by an applied magnetic field), for instance, between sealed containers or pressurised vessels. The optimal torque couplings consists of a pair of coaxially nested cylinders with opposite k and −k flux magnetization patterns, as this configuration is the only system for infinitely long cylinders that produces a torque. In the lowest-energy state, the outer flux of the inner cylinder exactly matches the internal flux of the outer cylinder. Rotating one cylinder relative to the other from this state results in a restoring torque.