The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

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In order to design lighter and faster hydraulic excavator, a rigid-flexible hybrid modeling method based on rigid multi-body dynamics and finite element method was put forward to study the dynamic characteristic of hydraulic excavator in its whole working cycle. The working equipment with characteristic of time-varying structure was taken as research object, and radial acceleration was computed as tags of key load.

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Moreover we formulize the optimal path according to the theory of B-spline Curve, so the path which is composed by the grid point can transform into a continuous and smooth curve. By formulizing path we can also calculate angular velocity, angle acceleration, and torque in dynamics.

另外我們根據(jù)B-spline Curve的理論將最佳路徑參數(shù)化，使由格點(diǎn)所組成的最佳路徑轉(zhuǎn)換為一條連續(xù)且平滑的曲線日本黄色A片视频在线观看，藉此我們也可以計(jì)算動力學(xué)中的瞬間角速度精品国产污污免费网站入口下载、角加速度與力矩。

There was a negative correlation between the overall magnitude of acceleration and both the center-edge angle and the acetabular head index, and there was a positive correlation between the overall magnitude of acceleration and both the acetabular roof angle and the Sharp angle.

在所有的加速度量值與CE角和臼頭指數(shù)之間有負(fù)相關(guān)青青草国产亚洲欧洲，在所有加速度量值與臼頂角和Sharp角之間有正相關(guān)亚洲麻烦在线视频。

The conclusion is that the extent of the zenith blind zone was restricted by three parameters: maximum azimuth angular velocity of tracking mount, flight level and airspeed of the target. In astronomical coordinates (reference mark is north latitude 43. 9°), analyzed is the effect of azimuth angular velocity, acceleration and altitude angular velocity, acceleration etc. Some formulae were given to compute all correlative quantities.

在觀測坐標(biāo)系中推導(dǎo)出確定天頂盲區(qū)理論范圍公式和滿足過天頂跟蹤條件的關(guān)系式；在天文坐標(biāo)系中以長春衛(wèi)星觀測站（北緯43.9°）作為計(jì)算基準(zhǔn)自在自线亚洲А∨天堂在线，分別討論了方位欧美性爱视频看、俯仰方向的角速度、角加速度等對天頂盲區(qū)的影響全国最大A片视频网，在理論分析上為解決過天頂跟蹤問題打下了基礎(chǔ)国产色无码免费无码视频软件。

The conclusion is that the extent of the zenith blind zone was restricted by three parameters: maximum azimuth angular velocity of tracking mount, flight level and airspeed of the target. In astronomical coordinates (reference mark is north latitude 43.9 ), analyzed is the effect of azimuth angular velocity, acceleration and altitude angular velocity, acceleration etc. Some formulae were given to compute all correlative quantities.

在觀測坐標(biāo)系中推導(dǎo)出確定天頂盲區(qū)理論范圍公式和滿足過天項(xiàng)跟蹤條件的關(guān)系式在线黄片m；在天文坐標(biāo)系中以長春衛(wèi)星觀測站(北緯43.9°)作為計(jì)算基準(zhǔn)，分別討論了方位日韩精品青青视频在线观看免费下载、俯仰方向的角速度久久久国产99久久国产产、角加速度等對天頂盲區(qū)的影響，在理論分析上為解決過天頂跟蹤問題打下了基礎(chǔ)欧美三级视频播放在线观看网址。

The angular accelerations after planning are easy to be implemented.

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Since the feature of joint's movement. Both knee's angular accelerations in two techniques are different from each other.

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Motion sickness is one of the most important problems in the field of space medicine.

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Numerical simulation results demonstrate that active suspension with a proper control strategy can decrease the roll angle and roll angle acceleration of the truck cab, the active suspension can improve both the ride comfort and driving safety.

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