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>Role of structural deformations of the crank-slider mechanism in the computation of the instantaneous frictional losses of a single cylinder engine.
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Role of structural deformations of the crank-slider mechanism in the computation of the instantaneous frictional losses of a single cylinder engine.
Reductions in engine frictional losses improve the engine efficiency, which enhances the vehicle fuel consumption and reduces the tail pipe HC, CO and NOx emissions. This goal cannot be achieved without the development of reliable methods for measuring instantaneous frictional losses in engines. The focus of the current study is to build on previous work by enhancing the accuracy of the ( P–ω) method in order to determine the overall instantaneous frictional losses of internal combustion engines under both transient and steady-state modes of operation.; The present work has concentrated on identifying the sources leading to erroneous results of the (P–ω) method. This was performed in a completely controlled environment, whereby a detailed model of the crank-slider mechanism is used as a test bed to yield the engine friction torque and to generate the combined rigid and flexible motions of the crank-slider mechanism. The rationale is to isolate the results of this study from the effects of measurement errors and/or noise interference.; The simulation results have demonstrated that the structural deformations of the crank-slider mechanism can adversely affect the computation of the instantaneous engine friction torque. Furthermore, the use of a low-pass filter to attenuate the contributions of the higher order dynamics of the system has been proven herein to be ineffective due to the nonlinearities of the system that have induced superharmonic and combination resonance frequencies in the crankshaft angular motion.; Therefore, a scheme for estimating the structural deformations of the crank-slider mechanism has been proposed. The digital simulation results have demonstrated that the estimated structural deformations of the crank-slider mechanism can be successfully implemented to extract the rigid body behavior from the measured angular motion of the crankshaft. The use of the corrected rather than the measured angular motion of the crankshaft have significantly improved the accuracy of the (P–ω) method in estimating the instantaneous engine friction torque.
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机译：减少发动机摩擦损失可提高发动机效率，从而提高车辆燃油消耗并降低尾管 HC ， CO 和 NO x 排放。如果没有开发用于测量发动机瞬时摩擦损失的可靠方法，就无法实现该目标。当前研究的重点是在以前的工作基础上，通过提高（ –ω）方法的准确性，以确定瞬态和稳态下内燃机的整体瞬时摩擦损失。状态操作模式。当前的工作集中在确定导致（ P -ω）方法错误结果的来源。这是在完全受控的环境中执行的，因此，曲柄滑块机构的详细模型用作测试台，以产生发动机摩擦扭矩并产生曲柄滑块机构的刚性和挠性组合运动。基本原理是将本研究的结果与测量误差和/或噪声干扰的影响区分开。仿真结果表明，曲柄滑块机构的结构变形会对发动机瞬时扭矩的计算产生不利影响。此外，由于系统的非线性在曲轴角运动中引起了超谐波和组合共振频率，因此已经证明使用低通滤波器来衰减系统的高阶动力学的贡献是无效的。 ;因此，提出了一种用于估计曲柄滑块机构的结构变形的方案。数字仿真结果表明，曲柄滑块机构的估计结构变形可以成功地实现，以从测得的曲轴角运动中提取刚体行为。校正后的曲轴角运动（而不是测量的曲轴角运动）的使用显着提高了（ P -ω）方法在估算瞬时发动机摩擦转矩方面的准确性。
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