Chenguang Cai received his Ph.D. degree in Precision Instrumentation and Mechanics from School of Instruments Science and Optoelectronic Engineering, Beihang University, Beijing, China, in 2007. From 2007 to 2009, he worked in Nokia Research Center (Beijing) as a Post doctor. He is currently an associate research fellow in National Institute of Metrology, Beijing, 100029, China. He was a visiting scientist in Physikalisch technische Bundesanstalt (PTB), Germany, in 2016. He is interested in vibration calibration and optics measurement.
EDUCATION
1997-09-01 to 2007-07-31 | Ph.d (School of Instrumentation Science and Opto-electronics Engineering ), Beihang University, Beijing, CN
Monocular Vision-Based Key Dynamic Parameters Measurement Method Used for Typical Bridge Structures Health Monitoring Guowei Chen, Chenguang Cai, Ming Yang, Deguang Wang, Chengbin Liang, Jiansheng Yang IEEE Sensors Journal, 2025 The key dynamic parameters measurement of bridge structures is essential to their health monitoring and has been highly valued. However, the commonly used accelerometer- or linear variable displacement transducer (LVDT)-based measurement methods have inevitably appeared in issues such as: measurement inconvenience, poor real-time performance, high cost, and low accuracy. In this study, a new monocular vision (MV)-based key dynamic parameters measurement method used for typical bridge structures health monitoring is proposed, which is capable of improving the performance with a commercial camera. This method combines the reliable camera calibration with a simple ring mark and improved sub-pixel Zernike moment edge extraction with linear ramp gray-scale model to accurately measure the key dynamic parameters. The laboratorial comparison experiments with the current accelerometer-based method (AM) at different working conditions to measure the acceleration, frequency, and deflection at the mid-span of a self-built bridge model were performed. The maximum relative deviations of the acceleration amplitude, frequency and deflection measured in the mid-span between the accelerometer-based and proposed methods were 0.52%, 1.35%, and 2.51%, respectively. Additionally, the comparison experiments on a practical bridge were also accomplished, and the results demonstrated that the proposed method can obtain a considerable measurement performance.
A Superefficient Monocular Vision Dynamic Calibration Method Used for Determining the Sensitivities of Low-Frequency Linear and Vibration Angular Sensors Ming Yang, Jing Zhang, Chenguang Cai, Ying Wang, Zhihua Liu, Deguang Wang IEEE Transactions on Industrial Electronics, 2024 The linear and angular vibration sensors are essential to the motion control and measurement, which have been widely used in various industrial applications. However, the current vibration calibration methods always failed to determine their sensitivities in the low-frequency range with a high efficiency. In this letter, a new calibration method that is based on the multifrequency sinusoidal signal generation with prime ratio and excitation measurement with sine approximation fitting solution is proposed, which can significantly improve the efficiency by integrating the calibration of multiple frequencies. This method calibrates the sensitivities at different frequencies in the range from the base frequency to its ten times frequency, which only requires a single operation. Comparison experiments with the two conventional monocular vision method and laser interferometry show that the investigated method can improve the calibration efficiency by at least an order of magnitude with a similar accuracy in the 0.01–10 Hz.
Symmetric Differential Demodulation-Based Heterodyne Laser Interferometry Used for Wide Frequency-Band Vibration Calibration Ming Yang, Chenguang Cai, Deguang Wang, Qinmu Wu, Zhihua Liu, Ying Wang IEEE Transactions on Industrial Electronics, 2024 The accelerometers are commonly applied to measure the vibrations in the fields of motion control and precision measurement, whose sensitivities are essentially important to their applications. The vibration calibration is utilized to determine their sensitivities before they are used or after a period of time. At present, the Nyquist sampling (NS), bandpass sampling (BPS), and mixer and low-pass filter sampling (MLPFS) based heterodyne laser interferometry are widely utilized to accomplish the vibration calibration. Compared with the NS method, the latter two methods can significantly reduce the sampling rate and extend the calibration frequency range. However, the BPS method has to adopt the complex algorithm and prior information so as to get its sampling rate, and the MLPFS method is inevitably influenced by an extra phase delay. In this article, a novel heterodyne laser interferometry is investigated to simultaneously determine the sensitivity magnitude and phase of the accelerometers with high accuracy in a wide frequency range. This method significantly eliminates the phase delay by introducing an appropriate symmetric differential demodulation strategy, which can improve the sensitivity phase calibration accuracy, especially at higher frequencies. The comparison experiments with the Earth's gravitation and monocular vision methods at low frequencies and the traditional MLPFS and NS methods confirm that the investigated method can calibrate the sensitivity magnitude and phase of accelerometers with the uncertainties of about 0.5% and 0.5° in the range from 0.1 Hz to 20 kHz.
A Numerical Approximation Approach for Deriving Computational Efficient Inverse Dynamics of 6-DOF Parallel Robots Based on Principle of Virtual Work Zhihua Liu, Chenguang Cai, Ming Yang, Zhufeng Shao, Qi Lv IEEE Robotics and Automation Letters, 2024 The inverse dynamics of the six degree-of-freedom (6-DOF) parallel robot (PR) presents an inherent complexity due to the closed-loop kinematic chains. To derive computational efficient inverse dynamics for real-time control, this study presents a numerical approximation (NA) approach based on the principle of virtual work. The analytical integration of the inertial wrenches is conducted for more concise formulas and then the numerical differentiation of these formulas is presented for more computational efficient inertial wrenches. The principle of virtual work is applied to derive the inverse dynamics by using the numerical inertial wrenches together with the analytical Jacobian matrices. The NA approach can reduce the computational cost of the inverse dynamics by up to 27% with a considerable computational accuracy. The real-time experimental results demonstrate that the NA approach has shortened the time interval of driving force compensation and significantly reduced the trajectory tracking error from 2.59 mm to 0.51 mm.
Three-component primary vibration calibration system at NIM 4th Imeko Tc22 Conference on Vibration Measurement 2017 Held Together with Tc3 and Tc5, 2017
Three-component primary vibration calibration system at nim 4th Conference on Vibration Measurement Together with 23rd Tc3 Conference on the Measurement of Force Mass and Torque and 13th Tc5 Conference on the Measurement of Hardness, 2017
Multi-exciter vibration control for spatial orbit motion 4th Imeko Tc22 Conference on Vibration Measurement 2017 Held Together with Tc3 and Tc5, 2017
Multi-exciter vibration control for spatial orbit motion 4th Conference on Vibration Measurement Together with 23rd Tc3 Conference on the Measurement of Force Mass and Torque and 13th Tc5 Conference on the Measurement of Hardness, 2017
Measurement of time delay caused by mixer and lowpass filter in heterodyne interferometer 4th Imeko Tc22 Conference on Vibration Measurement 2017 Held Together with Tc3 and Tc5, 2017
Measurement of time delay caused by mixer and lowpass filter in heterodyne interferometer 4th Conference on Vibration Measurement Together with 23rd Tc3 Conference on the Measurement of Force Mass and Torque and 13th Tc5 Conference on the Measurement of Hardness, 2017
Study on a simplified implementation of homodyne TIA method for low frequency primary vibration calibration 21st Conference on Measurement of Force Mass and Torque Together with Hardmeko 2010 and 2nd Meeting on Vibration Measurement Imeko Tc3 Tc5 and Tc22 Conferences, 2010
Measurement and evaluation of damping properties of damping material 21st Conference on Measurement of Force Mass and Torque Together with Hardmeko 2010 and 2nd Meeting on Vibration Measurement Imeko Tc3 Tc5 and Tc22 Conferences, 2010
