When an Army Special Forces officer-turned engineer puts his mind to designing a military riflescope, he doesn’t forget the importance of creating something for the soldiers who will carry it that is easy to use, extremely accurate, light-weight and has long-lasting battery power.
Sandia National Laboratories optical engineer Brett Bagwell led the development of theRapid Adaptive Zoom for Assault Rifles(RAZAR) prototype.
At the push of a button, RAZAR can toggle between high and low magnifications, enabling soldiers to zoom in without having to remove their eyes from their targets or their hands from their rifles.
“推动纽扣概念背后的动力是你可以在低放大率上获得你感兴趣的东西，而没有丢失，放大更多透明度，”Bagwell说。
In addition to military riflescopes, RAZAR technologies are now being considered for other applications where speed, size, weight and power count.
应用包括医学成像，双筒望远镜，用于军人到观鸟者的整个用户，猎人的范围和手机相机，需要光学变焦，以避免与数码变焦相关联的像素化图像。
Adaptive Zoom is Sandia’s Answer to DoD Call for Riflescope
Bagwell began work on RAZAR in 2006 responding toDepartment of Defense对压缩缩放步枪的兴趣可以在放大倍率之间快速切换。早期的工作得到了桑迪亚的资助实验室指导研发计划。
Bagwell没有发现商业产品或组件that would enable the riflescope to meet military requirements, so he had to design and build the first RAZAR from scratch and develop a manufacturing process.
Razar Prototype使用专利的有源光学变焦系统，称为“自适应变焦”，由David Wick发明，他当时作为桑迪亚光学工程师工作。
Traditional optical zoom changes magnification by adjusting the positions of the lenses along the optical axis. For example, a 35-mm camera mechanically moves the lenses as you zoom in on or out from a subject.
Adaptive zoom changes the focal lengths of two or more lenses by varying the curvature of the lenses’ surfaces to provide optical zoom without changing their overall positions relative to one another, allowing the user to view either a wide-angle image or zoom in on an area of interest with a compact, low-power system, Wick said.
这inventionBagwell表示，意味着“这是第一次在很长一段时间里，直视光学设计师可以利用的新技术。”
Three core technologies make adaptive zoom work for RAZAR:
- A polymer lens core has two flexible, hermetically sealed membranes, which encapsulate a polymer fluid. The three-quarter-inch lenses are aligned with glass lenses to complete the optical design.
- A piezoelectric actuator electro-mechanically changes the flex of the lenses, achieving the correct position within 250 milliseconds to an accuracy of 100 nanometers, about 1/100th the thickness of a human hair. These actuators operate the way the muscles of the human eye change the curvature of the eye’s lens to focus far away or up close.
- Variable-focal length system design tools had to be developed from scratch, including analytical expressions and computer models that trace rays of light through optical systems.
Riflescope’s Peak Optical Quality Half a Light Wave
Variable optical lenses were first developed in the late 1800s, but had few applications because of the limitations of materials. Adaptive zoom accomplishes true optical zoom (as opposed to digital zoom) by changing the focal length of two or more lenses in concert, without the normal mechanical motion, reducing the size and power requirements of the zoom lens, Wick said.
自20世纪60年代以来，Zoom Scopes Zoom Scopes的理论并没有显着变化，直到自适应Zoom技术出现。使用自适应变焦，桑迪亚的团队工作了18个月，以实现光的光学质量约为光的一半。
制造过程开发，以保证镜头质量
桑迪亚必须完善镜片的制造过程，因此可以复制原型的质量。Bagwell表示，当聚合物密封时，没有气泡或灰尘的灰尘可以留在镜片上或周围环上。
弗雷迪圣地亚哥，当时是谁是物理学和桑迪亚的博士候选人学生实习计划, developed the process for making the lenses.
“You have to start from the basics: How do we make the polymer? How do we stretch the polymer and make it an optical surface? We had to understand the process, from mixing the polymer all the way to the final product and we had to do it in a systematic way,” Santiago said.
小型企业敲击设计执行器
虽然构成步枪浮雕的许多技术和设计来自机械工程师，机器人专家，化学家和其他桑迪亚专家，Bagwell出席了执行器的实验室，以弯曲镜头，寻求帮助Dynamic Structures and Materials, LLC, a small business in Franklin, Tennessee.
Matthew Stefanick, who was the company’s lead engineer on the project, said the team used an ultrasonic piezo motor to actuate the flex in the lenses. A voltage is applied at an ultrasonic frequency to vibrate and move a rotor and lead screw, which causes the lens to flex.
Stefanick表示，使用超声波电机的决定提供了一个关键特征，即使电源丢失，即使电源丢失也是一个关键的功能，它是一个保持最后选择的焦点。
这feature allows users to complete 10,000 actuations on two AA batteries, Bagwell said.
满足鲍威r usage, speed and accuracy specifications required by the military took years. “As an engineer, I was impressed with our progress,” Bagwell said. “But as an operator, I was constantly dissatisfied. We had to make it smaller. We had to make it lighter. It’s got to toggle faster.”
前警长说，步枪普罗普可以挽救生命
Bagwell表示，从2010-2012
By 2010, Bagwell began demonstrating it to the military and, in late 2012, tested it with representatives from U.S. Special Operations Command atCamp Atterbury Joint Maneuver Training Center靠近爱丁堡，印第安纳州。当他把步枪交给军事人员时让他们测试它们，他意识到桑迪亚制定了一个将使军队有益的概念。
“The guys picked it up and when they pushed the button and it zoomed, and then instantly it zoomed back out, they were like kids at Christmas. There was this look of astonishment and pleasure,” he said. “That’s very gratifying. Here’s this grizzled veteran looking at me like I’ve just created magic.”
迈克尔郡，然后是一名中士一流，具有特殊运营研究支持元素，表示能够在几秒钟内放大近近的目标，而不脱掉武器，是“游戏变化”。
“The difference that can make, especially with somebody shooting back, could mean life or death,” he said.
曾尝试过Razar的前军事人员和士兵的反馈有动机的Bagwell。他现在正在努力开发夜视系统，最近展示了热红外的自适应变焦。
“It’s an opportunity for me to take my technical expertise and give back to people I really care about,” he said.
提起：Materials • advanced
