Processor thermal control in real-time systems is crucial because overheated processors may result in critical performance degradation or even system failure. The main challenges in processor thermal control in real-time systems are as follows: (i) the need to satisfy both real-time and thermal constraints; (ii) uncertain system dynamics; and (iii) thermal sensor noise. The first two issues have been resolved in substantial studies while the issue of sensor noise has not been thoroughly addressed. In this paper, we experimentally identify that even a small zero-mean sensor noise can induce a significant steady-state error in processor thermal control. This steady-state temperature error is contrary to the intuition that zero-mean sensor noise normally induces zero-mean fluctuations around the target temperature. We rigorously analyze the phenomenon based on the stochastic averaging theory and quantify the error in a closed form in terms of noise statistics and system parameters. We propose a thermal control architecture for effectively eliminating the thermal error and tightly controlling the processor temperature. Through extensive experiments, we validate the proposed architecture.

中文翻译：

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处理器热控制中噪声引起的温度误差分析与消除

实时系统中的处理器热控制至关重要，因为过热的处理器可能会导致严重的性能下降甚至系统故障。实时系统中处理器热控制的主要挑战如下： (i) 需要同时满足实时和热约束；(ii) 不确定的系统动态；(iii) 热传感器噪声。前两个问题已在大量研究中得到解决，而传感器噪声问题尚未得到彻底解决。在本文中，我们通过实验确定即使很小的零均值传感器噪声也会在处理器热控制中引起显着的稳态误差。这种稳态温度误差与零均值传感器噪声通常会在目标温度附近引起零均值波动的直觉相反。我们基于随机平均理论严格分析该现象，并根据噪声统计和系统参数以封闭形式量化误差。我们提出了一种热控制架构，以有效消除热误差并严格控制处理器温度。通过广泛的实验，我们验证了所提出的架构。