为实现机器人末端位姿多自由度实时测量反馈，融合一维光学位置传感器（Position Sensitive Detector，PSD）建立了平面3自由度非接触测量系统，对其测量原理，信号处理电路，环境光干扰去除和非线性标定算法等进行研究。根据PSD传感器测量特性和平面3自由度测量要求设计了4-PSD测量系统，并建立测量系统数学模型。研究了PSD传感器的信号处理电路，通过运放和除法器实现了单个PSD的信号处理，结合单片机与A/DC采样电路，实现了上位机的高频率信号采集。对4-PSD测量系统进行预实验，为消除环境光干扰，通过激光调制和数字滤波等方法进行验证。最后，通过激光位移传感器标定4-PSD测量系统，介绍了4-PSD的标定步骤（原点、转角、长度和二阶非线性标定），测定了系统标定后的误差分布。该测量系统具有较高的测量频率（50 Hz）。标定实验结果表明：标定后的4-PSD测量系统在70 mm×70 mm内，测量精度平均为0.49 mm，比标定前降低了90%的误差，能满足大部分高速、高精度机器人末端的非接触式实时测量反馈需求。

In this paper, we demonstrate a high-sensitivity and real-time heterodyne coherent optical transceiver for intraplane satellite communication, without digital-to-analog converter (DAC) devices and an optical phase lock loop (OPLL). Based on the scheme, a real-time sensitivity of -49 dBm is achieved at 5 Gbps QPSK. Because DAC is not needed at the transmitter, as well as OPLL at the receiver, this reduces the system cost. Furthermore, the least required Rx ADC bit-width is also discussed. Through theoretical analysis and experimental results, our cost-effective transceiver satisfies the scenario and could be a promising component for future application.

This study introduces a handheld terahertz (THz) scanner designed to quantitatively evaluate human skin hydration levels and thickness. This device, through the incorporation of force sensors, demonstrates enhanced repeatability and accuracy over traditional fixed THz systems. The scanner was evaluated in the largest THz skin study to date, assessing 314 volunteers, successfully differentiating between individuals with dry skin and hydrated skin using a numerical stratified skin model. The scanner measures and displays skin hydration dynamics within a quarter of a second, indicating its potential for real-time, noninvasive examinations, opening up opportunities for in vivo and ex vivo diagnosis during patient consultations. Furthermore, the portability and ease of use of our scanner enable its widespread application for in vivo and ex vivo diagnosis during patient consultations, potentially allowing in situ biopsy evaluation and elimination of histopathology processing wait times, thereby improving patient outcomes by facilitating simultaneous tumor diagnosis and removal.