基于CORDIC算法的360°角度传感器的设计

一维霍尔板型角度传感器无法测量0～360°的角度,采用4个霍尔器件的联合测角技术和CORDIC算法可实现0～360°范围内的角度测量。文章详细描述了4个霍尔器件联合测角技术的测角原理及实现算法,并引入了符号幅值表示法,即先利用正弦和余弦的幅值进行0°～90°范围内的反正切CORDIC运算,再根据正弦和余弦正负号(符号)的不同组合实现角度从0°～90°到0°～360°的映射。Modelsim平台仿真验证了该方法的准确度和精度,仿真误差小于0.01%,实测总误差不大于0.05°。     

一种3—3夹心复合智能机械手测距觉超声传感器

本文作者研制成一种新颖3-3夹心复合压电高频测距觉传感器.它们的谐振频率分别为430 kHz及1 MHz;带通标称Q值为10;通常内谐振接收电压灵敏度分别为—50dB及—56dB(0dB=1V/Pa·m);指向性波束开角分别为3°及1.5°.     

一种新型磁敏集成角度传感器及其测量系统

研制了一种无触点的十字形两维集成垂直霍尔器件 ,它对平行于芯片表面的磁场敏感。当与被测转角θ的物件轴向相连的径向永久磁铁转动时 ,传感器给出了相对于被测角度的两种信号电压 ,通过接口电路和PC机组成的非接触式测量系统把信号转换为转角θ。测试结果表明该角度传感器及其测量系统的测量精度在 0°～ 36 0°范围内可达± 1°     

检测电压对一种新型谐振式微加速度计的影响

静电作用在在平行板电容器上会产生等效静电负刚度,介绍了基于静电刚度的谐振式微加速度计设计原理,建立了其动力学模型.根据检测电压的约束条件,求解了其可行范围.同时分析了检测电压对系统灵敏度、可靠性和量程及输出电压的影响.分析结果表明:检测电压越大,灵敏度越大,但可靠性和量程会相应减少,反之亦然;直流检测电压的存在使得输出电压不受检测电容并行的寄生电容影响.理论分析结果为谐振式微传感器的系统设计提供了重要依据.     

红外焦平面阵列传感器中带隙基准源的设计

本文提出一种适用于红外焦平面阵列传感器的高精度BiCMOS电压基准和电流基准设计方案。该方案采用新型电压基准输出级降低Brokaw带隙基准源中的厄尔利效应使电流镜电流完全匹配,同时减小电压基准的输出阻抗;接着利用共源共栅结构的偏置电流提高带隙基准的电源抑制（Power Supply Rejection,PSR）特性;最后通过四个MOSFET管将基准电压和电阻电压钳制相等,进而得到一个高精度、低温度系数的电流基准;而以单个二极管连接的MOSFET作为电流基准启动电路的方式,可更进一步降低电路复杂性。系统采用CSMC 0.5um BiCMOS工艺,利用Cadence Spectre工具对电路进行仿真。结果表明,在电源电压5V,-40°C到125°C温度范围内,基准电压和基准电流的温度系数分别为13.11ppm/°C和31.18ppm/°C,输出电流波动低于0.5%,整体电路的PSR为-86.83dB,解决了恒定跨导基准源精度低的缺陷,符合红外焦平面阵列对基准源高精度、高PSR和低功耗的要求。     

MEMS圆盘谐振器形变对电气刚度影响分析

电气刚度是影响MEMS谐振器谐振频率精度的因素之一。但是对于谐振器受到应力时,产生的形变量对电气刚度的影响的理论研究报道甚少。鉴于此,本文对电容式盘结构谐振器受径向静电力和纵向惯性力下的形变量以及电气刚度的改变量进行了系统的理论分析。研究结果表明,当圆盘与电极间隙为50 nm,且电压达到50 V时,圆盘由于静电力产生的径向形变量可达间隙的2.05%,电气刚度改变6.15%。当圆盘半径为100μm,且受到10 000 gn的纵向惯性力时,其最大形变量可以达到圆盘厚度的2.4%,电气刚度改变2.4%。本文分析结果对其他盘结构谐振器的分析亦有重要借鉴意义。     

无电阻带隙基准电压源

本文提出了一种无需使用电阻的带隙基准电压源。采用反函数方法,利用两对成比例的源耦差分对产生基准中与温度成正比(PTAT)的电压项。该电路实现了一阶温度补偿,在0.6μmCMOS工艺条件下,电路spectre模拟仿真结果表明,在-45°C～-80°C范围内,输出电压变化低于1mV。电源电压为4V时,功耗为52μW。     

基于移相控制的LLC感应加热电源的研究

为实现串联谐振负载匹配,在电压型串联谐振感应加热电源的基础上,设计了一种适用于大功率高频感应加热的LLC拓扑结构.即在谐振回路中加入匹配电感,通过调整参数达到负载输出功率匹配的目的;采用负载频率跟踪技术与全桥移相脉冲宽度调制PWM功率调节方法相结合的控制方案,根据LLC谐振回路的特性,将输出电压和电容电压相位角作为锁相环控制变量.仿真及实验证明,这种拓扑方法相对于传统的LC串联谐振拓扑,更能满足高频大功率调功应用的需求,且移相控制使逆变器工作在软开关状态,降低了电源在高频工作时的开关损耗.     

FSC方程式赛车单体壳车架设计

车架质量占赛车整车质量的比例很大,其在轻量化方面存在可优化空间。利用CATIA设计一种钢管桁架结构和单体壳结构的复合式车架,在HyperMesh中建立有限元模型,对车架的单体壳部分进行尺寸优化,确定不同区域层合板的最佳厚度,最终得到的车架质量为21.8 kg,扭转刚度为4 057 N·m/(°),较纯钢管车架减重约5 kg,刚度提高约1倍,满足设计目标。     

CITECT组态软件在电弧炉计算机监控系统中的应用

在电弧炉炼钢中 ,炉体和电极的控制是其核心难点之一。炉体的控制是指倾炉控制 ,主要是出钢 (前倾 4 5°)和出渣 (后倾 15°)两个过程 ;电极的控制主要是指其升降控制 ,其控制依据是电极的电流。以前的倾炉控制完全是人工操作 ,很难达到预期的控制目的。引入计算机监控后 ,不仅能达到动态实时监控 ,而且大大降低了操作人员的劳动强度 ,提高了成品钢的质量。1　控制系统原理及硬件组成本控制系统下位机由 3套OMRONC2 0 0HPLC ,16台OMRON温度控制器 (E5CN )和 2台智能电表(EPM4 2 0 ,PSM330 )组成。上位机采用研华公司的工控机 ,组…     

基于关键点的类别级三维可形变目标姿态估计

为了解决类别级三维可形变目标姿态估计问题,基于目标的关键点,提出了一种面向类别的三维可形变目标姿态估计方法。该方法设计了一种基于关键点的端到端深度学习框架,框架以PointNet++为后端网络,通过特征提取、部位分割、关键点提取和基于关键点的姿态估计部分实现可形变目标的姿态估计,具有计算精度高、鲁棒性强等优势。同时,基于ANCSH方法设计了适用于K-AOPE网络的关键点标准化分层表示方法,该方法仅需提取目标少量的关键点即可表示类别物体。为了验证方法的有效性,在公共数据集shape2motion上进行测试。实验结果显示,提出的姿态估计方法(以眼镜类别为例)在旋转角上的误差分别为2.3°、3.1°、3.7°,平移误差分别为0.034、0.030、0.046,连接状态误差为2.4°、2.5°,连接参数误差为1.2°、0.9°,0.008、0.010。与ANCSH方法相比,所提方法具有较高的准确性和鲁棒性。     

胶囊内窥镜倾角传感式磁跟踪系统的设计

为了提高胶囊内窥镜的跟踪精度,增强实时性,提出了倾角传感与磁场传感相结合的无线跟踪方法。推导了倾角传感模块在跟踪系统中的角度测量原理,基于坐标旋转和空间磁场理论,建立了倾角传感式磁跟踪数学模型,获得了胶囊方位与磁场信号的数学关系式。根据倾角传感的磁跟踪方案,设计开发了系统样机,包括:磁场发生装置、倾角式无线磁传感模块、无线数据接收装置、数据处理平台。跟踪实验表明,角度跟踪平均误差为4.2°、4.5°,标准偏差为2.2°、2.4°;x分量、y分量、z分量的平均位置误差为0.011 3 m、0.012 1 m、0.010 4 m,标准偏差为0.008 2 m、0.007 5 m、0.006 8 m。倾角传感器的引入减少了励磁源的个数,减小了每轮跟踪的采样数据量和采样时间,简化了非线性方程组的求解,进一步提高了跟踪精度。     

Circularly polarized beam‐steering antenna array for ultra‐high frequency radio frequency identification applications

A circularly polarized beam‐steering antenna array with Butler matrix is designed in this letter for ultra‐high frequency radio frequency identification applications. To achieve the identification of the fast‐moving tag groups, a 3 × 4 Butler matrix is utilized to switch the radiation directions at ?25°, 0°, and +25°, respectively. Besides, series‐fed patch antenna element is designed and the 1 × 4 antenna array is built with element rotation for a good polarization performance. Finally, the proposed antenna system is fabricated and the identification area and radiation performance are tested.     

Analysis of upper-limb muscle fatigue in the process of rotary handling

Workers engaged in repetitive manual material handling (MMH) generally suffer from work-related musculoskeletal disorders (WMSDs), particularly in the arms, shoulders, neck, and waist; this significantly limits the individual's strength and ability to work. Currently, research on upper-limb injuries affecting manufacturing workers focusses on the effect of different working conditions on specific muscle fatigue. However, research on the fatigue transformation relationship among various muscles in the process of working is lacking. Therefore, the purpose of this study was to investigate the fatigue changes between the upper-limb muscles during rotary handing. In this study, 13 male subjects were studied to simulate rotating handling during the manual handling process using surface electromyography (sEMG). Handling angles of 90°, 45°, and 0° were arranged as single variables to conduct the single-factor experiment. The sEMG of the brachioradialis, biceps brachii, trapezius, and multifidus muscle was measured during the operation. The results of this study indicate that the characteristics of muscle fatigue are different at different rotation angles: the multifidus muscle and trapezius were fatigued when the rotation was 90°. Under the condition of a 45° rotation, the activities of the four muscles fluctuated significantly. The slope of the median frequency of the muscles was positive, the load of the four muscles was evenly distributed, and no local fatigue was observed. Under the condition of a 0° rotation, the sEMG indicated that the brachioradialis muscle was fatigued, while the other three muscles had lower loads.     

基于U弦长曲率的抗旋转性广义Hough变换算法

针对广义Hough变换(GHT)算法匹配发生旋转图像中的目标形状时发生误匹配的问题,提出一种基于U弦长曲率的具有抗旋转性的广义Hough变换算法。首先,对模板形状采用边缘点的U弦长曲率和偏移向量等特征构建具有旋转不变性的修改的R-表;其次,以图像中边缘点的曲率作为索引,查找构建的R-表得到偏移向量等信息;最后,根据查得的信息计算图像中目标形状的可能的参考点位置进行投票。根据投票结果即可提取出图像中目标形状的位置。当图像中目标形状分别旋转0°、2°、4°、5°、6°时,提出的算法的匹配结果均在图像中目标形状位置具有非常明显的峰值。仿真结果表明,改进的广义Hough变换(I-GHT)算法具有良好的抗旋转性和抗噪性。     

Compact bidirectional circularly polarized dedicated short range communication antenna for on‐board unit vehicle‐to‐everything applications

This article presents a newly circularly polarized (CP) antenna for V2X's dedicated short range communications applications. Its CP characteristic is enabled by a 70 Ω sequential phase feeding network and sequential rotation technique designed on top of the substrate. It has features of ≈90° phase difference in sequence between ports of S₂₁ = 2.4°, S₃₁ = ?87°, S₄₁ = ?180°, and S₅₁ = ?276°, resulting in a 2.19 dB axial ratio centered at 5.9 GHz. The length of the SP feeding network to each ports designed in the different form of meander lines are the key to control the generated phase at the center frequency It also contributes to the smaller final size of 0.59λ × 0.59λ. The proposed antenna operated from 5.850 to 5.925 GHz with a gain between 4 and 6 dBi. The gains are radiated in bidirectional mode due to the presence of the complimentary dipoles located on the opposite side of the substrate. These features indicate the suitability of the proposed antenna in compliance to the ITS‐G5 OBU V2X standard.     

飞机尾翼转角测量系统设计

针对飞机尾翼转角测量及远距离监控问题,设计了一种基于数字式MEMS加速度传感器测量飞机尾翼转角的测量系统;分析了电容式加速传感器测角原理;利用数字式MEMS加速度传感器ADXL345,结合无线ZigBee技术采用CC2430模块,以嵌入式STM32单片机作为控制器构建了一种测量飞机尾翼转角大小的测量系统;采用三维转台对飞机尾翼转动进行了模拟,完成了±90°范围内转角的测量;实验结果表明,在±90°转角范围内,测量误差的最大值为0.277°,满足小于0.3°的误差要求;该测量系统可以有效地完成飞机尾翼转角测量工作。     

一种基于FPGA的高速自整角机数字解算方法

自整角机是广泛应用于轴角测量系统中一种非常重要的测量元件,现场可编程逻辑门阵列(FP-GA)技术近几年的发展使得利用硬件描述语言实现信号的快速实时处理成为可能。设计采用Spartan-3系列的XC3S400芯片,根据自整角机输出信号的特点和角度测量原理,利用Verilog HDL语言编程完成控制逻辑和自整角机角信息的解算。应用坐标旋转数字计算机(CORDIC)算法在FPGA中实现了反正切函数的计算,并引入改进的CORD IC算法以提高运算速度,节省硬件资源。经过测试,达到0.01°的轴角解算精度,角度解算区间达到[-360°,360°],并且,在不同的角度偏移量和不同的轴初始位置情况下都能获得满意的结果。     

A wideband circularly polarized antenna using mutual coupling method

A novel wideband circularly polarized (CP) antenna is presented in this article. The proposed antenna consists of a four‐leaf clover patch, four L‐probes, and wideband networks. Based on the tightly coupled mechanism, the four L‐probes are formed as a ring with the adjacent ones kept close for strong mutual coupling. Consequently, the proposed antenna realizes a wideband impedance matching. Meanwhile, the four‐leaf clover patch is put closely inside of the ring for further improving the impedance bandwidth, which is proximity‐coupled fed by the four sequential‐rotation L‐probes with phase of 0°, 90°, 180°, and 270°. The four L‐probes are connected to the respective ports of a wideband feeding network by a two‐stage impedance transforming network. The measured results indicate that the proposed design has an impedance bandwidth of 66.7% from 1.0 to 2.0 GHz for VSWR ≤ 2 and a 3‐dB axial ratio bandwidth of 56.5% from 1.08 to 1.93 GHz. Furthermore, in the operating bandwidth, stable and symmetry radiation patterns and high gain are obtained. The design has a 3‐dB gain bandwidth of 38% from 1.3 to 1.9 GHz with a peak gain of 8.5 dBic.     

磁阻式传感器在角度测量中的应用

介绍一种利用磁阻式传感器构成的非接触角度自动测量系统。分析了非接触角度测量系统的结构、原理以及信号处理方法,给出了角度测试结果,系统的角度测量范围为0°~180°,测量精度为±0. 5°。