热电耦合无线传感能量管理系统及其在精密主轴热监测中的应用

Power management system for thermoelectric coupling wireless sensing and its application to thermal monitoring of precision spindle

针对无线传感器热电耦合自供能存在的输出电量低和电压波动等问题,提出一种新型能量管理系统电路拓扑结构及基于最优时间的充放电控制策略,以保证自供能无线传感器在各种主轴转速条件下稳定工作。建立了机床主轴的热网络模型,分析了热发电能量管理系统输入特性。然后,设计了能量管理系统的多电容电路拓扑结构,并通过电容充放电时间参数的优化计算,获取最优的热发电平均输出功率。实验研究证实了在主轴不同转速下热发电构件及能量管理系统可以使无线传感器稳定的工作。对不同的电容充电和放电时间设置方案进行了比对,验证了最优时间控制策略的优越性。最后,利用热电耦合自供能无线传感器和传统有线传感器所监测的温度数据分别进行了主轴轴向热变形建模实验,结果表明:采用无线传感器可以监测有线传感器难以配置的主轴核心部件,从而获取和主轴热变形具有更高相关性的温度数据,使所建热变形预测模型的误差减少约40%以上。

As the thermoelectric coupling self-powering of a wireless sensor has a lower power and a fluctuated voltage, this paper proposes a new Power Management System（PMS） and its optimal time control strategy to allow the self-power wireless sensor to work stably at different spindle speeds. A thermal network model for the tool spindle was established and the input characteristics of thermal generating power management system was analyzed. Then, a circuit topology with more capacitances for the power management system was designed, and the optimized average output power from thermal generating power was obtained by calculating the charging/discharging time parameters of capacitors. An experiment was performed, and it verifies that the wireless sensor works stably at different spindle speeds driven by thermal power generation devices and the power management system. Several schemes for setting charging/discharging time of capacitors were compared, and the superiority of the time control strategy was verified. Finally, the spindle axial thermal deformation models were established for the data from the thermoelectric coupling self-powering wireless sensor and the traditional wired sensor. The results indicate that the wireless sensor monitors the key part of the spindle that the traditional ones can not be installed in, by which the more directional temperature data relative to the thermal deformation of prediction are obtained, and the error of thermal deformation prediction model is deceased about 40 %.