다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

CDC (Continuous Damping Control) shock absorber is the typical representative of the stepless valve-controlled type, which has the advantages of low cost and stable performance. Based on the throttling characteristics of the CDC valve, the damping force mathematical model of the CDC shock absorber is established. Through simulation analysis, the indicator characteristics and speed characteristics of the CDC shock absorber under different input currents and speeds are obtained. A CDC shock absorber testbed is built to study damping characteristics, and the results are compared with the simulation results. The results show that the indicator diagram obtained by simulation and experiment is smooth without distortion, and the speed characteristic diagram is smooth without a large mutation point. The experimental values of damping force are slightly larger than the simulation values. The relative error between the simulation data and the experimental data is basically less than 10% and the model has high accuracy. When the input current is the same, the damping force increases with the increase of piston rod speed. When the speed of the piston rod is the same, the damping force of the rebound and compression stroke decreases with the increase of input current.

Theoretical and experimental research on damping characteristics of CDC shock absorber

A time-delayed acceleration feedback control is proposed to improve the vibration performance of a nonlinear vehicle suspension system. First, the harmonic balance method is applied to obtain the v...

https://journals.sagepub.com/doi/pdf/10.1177/1461348420979203

Control parameter optimization of a nonlinear vehicle suspension system with time-delayed acceleration feedback:

Design of independent full car suspension by using fuzzy control to improve ride comfort and steering ability of passenger car

In intelligent control systems of magnetorheological (MR) suspension of all-terrain vehicle (ATV), low-frequency disturbance (LFD) in the measured feedback signal (acceleration) makes the controller unable to calculate the theoretical control force accurately. In particular, when the frequency of the LFD signal is close to that of the actual acceleration signal, the LFD cannot be filtered by designing a traditional filter. Based on the above questions, this paper proposes an incremental proportion integration differentiation (IPID) strategy to address the issue of LFD in the measured feedback acceleration signal of the MR suspension system of ATV. First of all, the model of 1/4 vehicle suspension in consideration of LFD is established, the source of LFD is analyzed which is due to the transformation of Coriolis acceleration under the condition of vehicle body pitch and roll. Next, a semi-active IPID controller is designed by utilizing differential derivation of discrete PID and semi-active principle to eliminate the LFD component mixed in the acceleration signal by making a difference. The particle swarm optimization (PSO) algorithm is utilized to optimize the parameters of the controller, which is then verified through numerical simulation. Subsequently, a real vehicle control experiment is carried out based on a 4 × 4 ATV equipped with the MR suspension system and implemented by DSP controller with the designed IPID algorithm. The effectiveness of the proposed method is evaluated under the speed 10 km h−1 and E road, and the designed method is compared with the traditional proportion integration differentiation (PID) control algorithm through simulation and experimentation to demonstrate the superiority and rationality of ‘filtering out’ LFD signal and improving control effectiveness.

Incremental proportion integration differentiation control of all-terrain vehicle magnetorheological suspension system under low-frequency disturbances

A Smith predictor-Taylor series-based LQG (STLQG) control to compensate time delay of a semiactive suspension system is newly presented. This control consists of a Taylor series-based LQG (TLQG) control and a Smith predictor based on the TLQG. The TLQG control compensates one half of time delay to decrease magnification from whole time delay compensation. The Smith predictor based on the TLQG compensates the other half to decrease horizontal shift from whole time delay compensation using the Smith predictor-based LQG. Finally, a practical case illustrates advantages of the STLQG control.

/pdf/smith-predictor-taylor-series-based-lqg-control-for-time-109osr9j6p.pdf

Shian Chen

Papers

Smith Predictor-Taylor Series-Based LQG Control for Time Delay Compensation of Vehicle Semiactive Suspension