Active CMOS Sensor Array for Electrochemical Biomolecular Detection

Electrochemical sensing of biomolecules eliminates the need for the bulky and expensive optical instrumentation required in traditional fluorescence-based sensing assays. Integration of the sensor interface electrodes and active electrochemical detection circuitry on a CMOS substrate miniaturizes the sensing platform, enhancing its portability for use in point-of-care applications, while enabling the high-throughput, highly parallel analysis characteristic of traditional microarrays. This paper describes the design of a four-by-four active sensor array for multiplexed electrochemical biomolecular detection in a standard 0.25-$mu{hbox {m}}$ CMOS process. Integrated potentiostats, comprised of control amplifiers and dual-slope analog-to-digital converters, stimulate the electrochemical cell and detect the current flowing through the on-chip gold electrodes at each sensor site that results from biomolecular reactions occurring on the chip surface. Post-processing steps needed to fabricate a biologically-compatible surface-electrode array in CMOS that can withstand operation in a harsh electrochemical environment are also described. Experimental results demonstrating the proper operation of the active CMOS array for biomolecular detection include cyclic voltammetry of a reversible redox species, DNA probe density characterization, as well as quantitative and specific DNA hybridization detection.      

LIDAR Sensing for Vehicle Lateral Guidance: Algorithm and Experimental Study

This paper describes a new vehicle detection system based on a laser imaging, detection, and ranging (LIDAR) sensor, and conducts an experimental study to investigate the sensor's role in the current California PATH vehicle lateral guidance systems. The LIDAR sensor is installed on a controlled vehicle and it can measure the relative distance of the vehicle from a preceding vehicle, by scanning the horizontal plane with laser beams. Environmental clutter becomes the main challenge in data processing, when LIDAR tries to track the desired target. A probabilistic data association-based algorithm has been developed to solve this problem, which has been verified in real-time experiments using two Buick LaSabre vehicles. The experimental study also reveals the relation between the LIDAR outputs and the magnetic reference system widely used by the current PATH lateral control systems, and the results provide the guidelines on how this new sensor system may be used for vehicle lateral guidance     

Automated vehicle guidance using discrete reference markers

Techniques for providing steering control for an automated vehicle using discrete reference markers fixed to the road surface are investigated analytically. Either optical or magnetic approaches can be used for the sensor, which generates a measurement of the lateral offset of the vehicle path at each marker to form the basic data for steering control. Possible mechanizations of sensor and controller are outlined. Techniques for handling certain anomalous conditions, such as a missing marker, or loss of acquisition, and special maneuvers, such as u-turns and switching, are briefly discussed. A general analysis of the vehicle dynamics and the discrete control system is presented using the state variable formulation. Noise in both the sensor measurement and in the steering servo are accounted for. An optimal controller is simulated on a general purpose computer, and the resulting plots of vehicle path are presented. Parameters representing a small multipassenger tram were selected, and the simulation runs show response to an erroneous sensor measurement and acquisition following large initial path errors.     

基于激光传感器的自主寻径智能车设计

设计了一种基于激光传感器的自主寻径智能模型车系统,以飞思卡尔公司16位单片机MC9S12XS128为核心控制器;系统采用激光传感器阵列检测路径信息,得到智能车与路径的横向偏差,采用比例控制算法控制舵机转向,并对直流驱动电机进行增量式PID闭环调节控制,从而实现智能模型车快速稳定地自主寻径行驶。     

高冗余光纤光栅传感网络的设计与实验研究

结合无源光学器件,提出并设计了一种新型的高冗余光纤布拉格光栅(FBG)传感模块,并将设计的FBG传感模块与波分复用技术相结合,构建了高冗余FBG传感网络.以长方形铝合金板为研究对象,对高冗余FBG传感网络的可靠性进行研究,理论比较并实验分析了高冗余FBG传感阵列的适用性与可靠性.研究结果表明,利用光开关在传感阵列支路之间的切换,使得FBG传感网络更具有冗余性.这一方面能够解决使用过程中多个部位出现故障导致的某些FBG传感模块无法被计算机检测到的问题,有效提高了传感系统的可靠性、容错性;另一方面为工程应用中结构健康监测以及特殊部位监测提供了一种有效可行的监测手段.     

Perception for collision avoidance and autonomous driving

The Navlab group at Carnegie Mellon University has a long history of development of automated vehicles and intelligent systems for driver assistance. The earlier work of the group concentrated on road following, cross-country driving, and obstacle detection. The new focus is on short-range sensing, to look all around the vehicle for safe driving. The current system uses video sensing, laser rangefinders, a novel light-stripe rangefinder, software to process each sensor individually, a map-based fusion system, and a probability based predictive model. The complete system has been demonstrated on the Navlab 11 vehicle for monitoring the environment of a vehicle driving through a cluttered urban environment, detecting and tracking fixed objects, moving objects, pedestrians, curbs, and roads.     

阵列菲涅耳波带片波前探测性能研究

在高功率激光系统中,激光束小尺度畸变波前探测是实现激光束中频段波前补偿与控制的重要前提。采用阵列菲涅耳波带片作为激光束波前传感的子孔径分割器,研究其聚焦性能,讨论了波带片的结构如阵列数目和阵列尺寸对波前探测精度的影响。仿真结果表明,选取合适的波带片结构参数可以使小尺度畸变波前的重构误差小于十分之一个波长。为了检测阵列菲涅耳波带片作为波前传感器检测波前畸变的性能,实现小尺度波前畸变检测的目的,构建了激光波前畸变检测光路系统。实验结果表明了阵列菲涅耳波带片检测波前畸变的可行性和准确性.     

Appropriate Sensor Placement for Fault-Tolerant Lane-Keeping Control of Automated Vehicles

This paper deals with the sensor placement problem in the realization of failure-tolerant lane-keeping control of front-wheel-steered automated vehicles. The scenario considered is one in which lane-keeping action is performed using two sensors that independently measure the lateral deviation of their locations of installation from a reference. The problem of interest is to determine appropriate locations for their installation so that the vehicle can be steered safely even in the event of failure of one of the two sensors. It is shown that for safe lane-keeping action at low as well as high speeds, both sensors should be placed ahead of the rear axle of the vehicle. In addition, the paper discusses a pedagogical problem - namely, the lane-keeping control problem with lateral error information from a sensor placed behind the rear axle. It is shown that, contrary to intuition, it is easier to steer the vehicle at higher speeds. Results based on experiments conducted on vehicles used in the Partners for Advanced Transit on Highways (PATH) program demonstrate the validity of analytical predictions.     

A fingerprint sensor based on the feedback capacitive sensingscheme

This paper introduces a single-chip, 200×200-element sensor array implemented in a standard two-metal digital CMOS technology. The sensor is able to grab the fingerprint pattern without any use of optical and mechanical adaptors. Using this integrated sensor, the fingerprint is captured at a rate of 10 F/s by pressing the finger skin onto the chip surface. The fingerprint pattern is sampled by capacitive sensors that detect the electric field variation induced by the skin surface. Several design issues regarding the capacitive sensing problem are reported and the feedback capacitive sensing scheme (FCS) is introduced. More specifically, the problem of the charge injection in MOS switches has been revisited for charge amplifier design     

基于分布式光纤的网络化远程控制系统

随着光纤传感技术的发展,其逐渐呈现出网络化、并行监测与远程控制的发展趋势,为更好地利用光纤传感网络,设计基于分布式光纤的网络化远程控制系统。系统由使用层、存储层和服务层组成,包含分布式光纤传感器的服务层是系统的核心,其向存储层发送备案请求,将其中的光纤传感器地址存储在其中;使用层通过存储层获取可用地址列表,在其中任意控制一个或数个光纤传感器实施数据采集。使用层向服务层发送数据采集命令,服务层中嵌入式平台接收命令后传输至被控光纤传感器控制器执行采集命令,并将采集到的数据传输至FPGA内进行降噪、累计等处理,处理后的数据通过嵌入式平台反馈至使用层。实验结果显示,该系统控制下,光纤传感网络采集信息偏差低于5μrad,服务端响应时间提升25%以上,具有加高的噪声低抑制性能。     

Tin oxide gas sensor fabricated using CMOS micro-hotplates andin-situ processing

A monolithic tin oxide (SnO₂) gas sensor realized by commercial CMOS foundry fabrication (MOSIS) and postfabrication processing techniques is reported. The device is composed of a sensing film that is sputter-deposited on a silicon micromachined hotplate. The fabrication technique requires no masking and utilizes in situ process control and monitoring of film resistivity during film growth. Microhotplate temperature is controlled from ambient to 500°C with a thermal efficiency of 8°C/mW and thermal response time of 0.6 ms. Gas sensor responses of pure SnO₂ films to H₂ and O₂ with an operating temperature of 350°C are reported. The fabrication methodology allows integration of an array of gas sensors of various films with separate temperature control for each element in the array, and circuits for a low-cost CMOS-based gas sensor system     

A new device architecture suitable for high-resolution andhigh-performance image sensors

A device architecture for building high-performance and high-resolution image sensors suitable for consumer TV camera applications is introduced. The sensor elements are junction field-effect transistors that are organized in an array with their gates floating and capacitively coupled to common horizontal address line. The photogenerated signal is sampled one line at a time, processed to remove the element-to-element nonuniformities, and stored in a buffer for subsequent readout. The concept, which includes an intrinsic exposure control, is demonstrated on a test image sensor that has an 8-mm sensing area diagonal and 580 (H)×488 (V) pixels. The key performance parameters, in addition to a high packing density of sensing elements with a unique hexagonal shape, include high signal uniformity, low dark current, good light sensitivity, high blooming overload protection, and no image smear. The discussion covers the design and operation of the basic image-sensing element, the architecture of the array, and the operation of the on-chip circuits needed for addressing and processing of generated signals. The overall device performance is demonstrated by typical device characterization results     

基于FPGA的大面阵CMOS相机高速率电子学系统设计

目前深空遥感探测多采用CCD作为高分辨率相机的传感器,相较于CCD,面阵CMOS驱动更简单、功耗更低、抗辐射能力更强,是深空遥感探测目前的发展趋势。为此,本文基于CMOSIS公司生产的型号为CMV20000,图像分辨率为5 120×3 840的CMOS探测器,设计完成了一个大面阵CMOS高分辨率相机,图像分辨率为5 120×3 840。详细阐述了以FPGA为核心的电子学系统的整体结构,结合CMV20000的工作模式和时序电路,实现了高分辨图像的高速传输以及数据校正。试验结果表明,设计的相机系统方案合理,解决了CMV20000数据无法对齐的数据校正问题,系统运行稳定可靠,安装光学系统后能够获取高质量图像。     

Development of an automated steering vehicle based on roadwaymagnets-a case study of mechatronic system design

Automated steering control is a crucial element of vehicle automation. The California PATH Program at the University of California at Berkeley has developed one such system using magnetic markers embedded under the roadway for lateral guidance. This system was demonstrated during the August 1997 National Automated Highway System Consortium Feasibility Demonstration, San Diego, CA, without a single failure. Developing a successful demonstration system not only required theoretical understanding of the various control problems involved, but also strong appreciation of all practical issues. In the paper, the comprehensive process of developing such automated steering control system is described. This process consists of control objectives' determination, system structure definition, vehicle dynamics validation, lateral sensing system development, steering actuator design, test track installation, control algorithm development, software/hardware integration, and vehicle testing. The entire process also serves as a good case study for mechatronic system design integrating mechanical components, electronic devices, intelligence, and feedback control to perform vehicle automation functions     

High bandwidth tilt measurement using low-cost sensors

In this paper, a state estimation technique is developed for sensing inclination angles using low-cost sensors. A low-bandwidth tilt sensor is used along with an inaccurate rate gyro and a low-cost accelerometer to obtain the measurement. The rate gyro has an inherent bias along with sensor noise. The tilt sensor uses an internal pendulum and therefore has its own slow dynamics. These sensor dynamics were identified experimentally and combined to achieve high-bandwidth measurements using an optimal linear state estimator. Potential uses of the measurement technique range from robotics, to rehabilitation, to vehicle control.     

On the detection of vehicular crashes-system characteristics andarchitecture

Safety systems for ground vehicles are deployed in different phases according to the timing of activation relative to the occurrence instant of an accident. Collision warning or avoidance systems function prior to an accident, while occupant protection systems act during a collision to mitigate the damage or injuries caused by an accident. This paper deals with crash sensing systems that detect a collision and evaluate the severity of a crash. One major application of these sensing systems is their current use in occupant restraint systems. They may also be utilized in the future for advanced vehicle control and safety systems. With air bags becoming standard equipment in new passenger vehicles, crash sensing technologies have advanced considerably. Yet, existing challenges and new innovations continue to demand improvements in their functions. This paper focuses on the system performance of crash sensing systems. The purpose of this paper is to propose a framework of addressing various design issues from both a component level and a system perspective. Through the discussions of crash data analysis, the design concepts of crash sensors are highlighted. The characteristics of representative mechanical and electronic sensors are analyzed and the guidelines of sensor selection to meet design requirements are discussed. Also, an assessment of sensor reliability is reviewed with various system architectures. Finally, suggestions are made to enhance system performance in areas that may benefit from the addition of sensing functionality. The public has become conscientiously aware of the importance of transportation safety. With more advanced technologies introduced into ground vehicles, the safety concerns will intensify. The demand for a friendly driving environment and vehicle interior will further promote the requirements of vehicular safety systems. Crash sensing will remain a challenging and active area for years to come     

A log-polar image sensor fabricated in a standard 1.2-μm ASICCMOS process

A CMOS log-polar or foveated image sensor for use in mobile robotic and machine vision applications has been designed, fabricated, and tested. The sensor benefits from a high degree of integration, minimal power consumption, and ease of manufacture due to the use of a standard 1.2 μm ASIC CMOS process. The sensor is composed of two distinct CMOS imager arrays which together solve the problem of obtaining good image resolution over a wide field of view. With resolution sensing is accomplished with a 40×40 array of individual pixels each measuring 9.6 μm on a side. A wide field of view is provided by an array of 64×16 pixels arranged on a log-polar grid. The maximum measured dynamic range for the fabricated log-polar array is 46 dB, while the lowest observed fixed-pattern noise is 0.5% of saturation. Combined power consumption of both arrays is under 2 mW when operating from a single 5-V supply at a frame rate of 30 frames/s     

Monolithic Resonant-Cantilever-Based CMOS Microsystem for Biochemical Sensing

A resonant cantilever-based microsystem aimed at biochemical sensing is presented. The sensor system comprises a magnetically actuated resonant cantilever sensor array integrated with the feedback circuitry, digital control circuitry and a serial interface on a single chip in 0.8 $mu{hbox {m}}$ CMOS technology. The sensor system shows a frequency stability of better than 3 Hz in water corresponding to a detection limit of about 30 pg mass loading. The system has been used for the detection of antibody-antigen interaction on the cantilever surface. The possibility to actuate and operate cantilever arrays in a liquid environment opens up a variety of new applications for bio-chemical sensing.      

One-Component Artificial Gustatory System Based on Hydrogen-Bond Organic Framework for Discrimination of Versatile Analytes

Hydrogen-bond organic frameworks (HOFs) with excellent structural and luminescent properties have emerged as a promising material for the construction of fluorescence sensors. However, designing a facile, universal and high throughput sensor with multiplex detection capacity still remains challenging. Herein, a one-component sensor array is constructed that mimics natural gustatory system for accurate and high-throughput discrimination and identification of versatile analytes. HOF as a single sensing element greatly simplifies the probe preparation in sensor array and detection procedure. Metal ions, proteins and bacteria as the model targets are rapid and accurately discriminated, presenting the universality of the system. Particularly, the system is successfully used for the classification of antibiotic mechanisms. The study expands the application scope of HOFs and provides a facile and universal system for sensing applications.     

BOA技术在车辆感知网络中的应用研究

"车联网技术"的兴起,大量传感技术得到应用,受无线传输设备与传感器体积限制,信息只能单向传递,缺少与被感知设备间交互。提出一种通过BOA技术远程感知交通设备中部件访问的双向交互技术,配合虚拟独立地址技术可以达到部件分组独立控制。这样BOA通过CAN总线集成可以对设备整体进行全部部件监控和更多的优化操作,达到更大范围内的远程参数获取与监控。最后,通过具有BOA技术的实例证明,此种技术可行。