Industrial timer requirements are multifaceted. On-delay, off-delay, cyclic or sequential timing requirements, with usual time range varying from seconds to days, depending on the process. Custom build timers cannot p...Industrial timer requirements are multifaceted. On-delay, off-delay, cyclic or sequential timing requirements, with usual time range varying from seconds to days, depending on the process. Custom build timers cannot provide all of these requirements simultaneously and hence an advanced timer rectifying this shortcoming has been designed and fabricated in this work. This timer is based on the real time clock chip used in mother boards. Our design can be programmed for a specific time requirement and can later be put to work in standalone mode. A demonstration board is fabricated and tested.展开更多
文摘Industrial timer requirements are multifaceted. On-delay, off-delay, cyclic or sequential timing requirements, with usual time range varying from seconds to days, depending on the process. Custom build timers cannot provide all of these requirements simultaneously and hence an advanced timer rectifying this shortcoming has been designed and fabricated in this work. This timer is based on the real time clock chip used in mother boards. Our design can be programmed for a specific time requirement and can later be put to work in standalone mode. A demonstration board is fabricated and tested.
文摘分析了高精度数字时间间隔测量方法的优缺点,提出一种脉冲计数与相位延迟内插相结合的新型时间测量方法。由脉冲计数法保证大的动态测量范围,并设计双边沿计数器提高脉冲计数法的测时精度,降低计数量化误差。通过n次相位延迟内插将测时分辨率提高到量化误差的1/2n.在Xilinx Virtex 5平台上实现了参考时钟16次相位延迟内插与脉冲计数相结合的飞行时间测量系统,测试结果表明,基于FPGA的高精度回波飞行时间测量方法得到的测量误差能优于55 ps.
