Oscillation Loop for a Vibratory Gyroscope and Its Experiment Study

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Liu Heng ◽  
Su Wei ◽  
Zhang Fu-tang
Keyword(s):  
Signal To Noise Ratio ◽  
Gain Control ◽  
The Self ◽  
Experimental Results ◽  
Velocity Amplitude ◽  
Vibratory Gyroscope ◽  
Gyroscope System ◽  
Control Scheme ◽  
Oscillation Loop ◽  
The Stability

This paper investigates the design of a self-oscillation loop for the gyroscope system. The dynamic equations describing this system are analyzed using the method of averaging, and a criterion for selecting the circuit parameters is established based on the analysis. The validity of the criterion and the effectiveness of the control scheme are verified by the experimental results obtained from the control parameters that satisfy or violate the stability criterion. The performance of the self-oscillation loop with a z-axis gyroscope is also evaluated in light of the experimental results. The self-oscillation loop based on the auto gain control scheme effectively tracks the resonance frequency of a z-axis gyroscope. This frequency corresponds to a standard Allan variance of 0.04 Hz in 8 min at natural frequency. The output signal-to-noise ratio (SNR) is about 90 dB, and the vibratory velocity amplitude shows a deviation of 0.5% in 8 min.

The Research and Design of the Adaptive Automotive Headlamps Based LED System

2015 ◽  
Vol 742 ◽  
pp. 753-757
Author(s):  
Xu Sen Zhao ◽  
Shuo Bai
Keyword(s):  
Light Intensity ◽  
Power Supply ◽  
Analog Circuit ◽  
High Efficiency ◽  
Boost Converter ◽  
The Self ◽  
Experimental Results ◽  
Control Scheme ◽  
Self Adaptation ◽  
Research And Design

A new control scheme with self-adaption is put forward in this paper. The digital control and the analog circuit are combined. A light intensity sensor can be implemented with a photoelectric triode. This sensor makes the self-adaptation control of LED possible. As a result, the light of LED can be adjusted automatically with a PWM chopper according to the ambient brightness. The whole system’s power supply is from a Boost converter which has a high efficiency. In addition, This combination improves the hommization of the system and solves the problems existing incurrent headlamps, unsafe factors are also reduced. The validity of design is verified by experimental results.

scholarly journals Running Characteristics of Aerodynamic Bearing with Self-Lifting Capability at Low Rotational Speed

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Tadeusz Adam Stolarski
Keyword(s):  
Fourier Transform ◽  
Journal Bearing ◽  
Static Model ◽  
The Self ◽  
Experimental Results ◽  
Squeeze Film ◽  
Film Pressure ◽  
Squeeze Film Effect ◽  
Time Marching ◽  
The Stability

An aerodynamic journal bearing that is capable of self-generating squeeze-film pressure is presented and its dynamic characteristics investigated numerically and experimentally. A numerical method based on a time-marching static model was applied to assess the orbit trajectory path of the rotor upon a perturbation. Experimental results were obtained to validate the effect of the self-generated squeeze-film pressure on the stability of the rotor. Analyzing the Fast Fourier Transform (FFT) responses of the rotor orbits enabled identification of self-excited whirling instabilities. Both numerical and experimental results showed that increasing the squeeze-film effect of the bearing could raise the threshold speed of instability.

Analysis and Design of Drive Closed-Loop for MEMS Vibratory Gyroscope

2010 ◽  
Vol 159 ◽  
pp. 406-411
Author(s):  
Liang Yang ◽  
Yan Su ◽  
An Ping Qiu ◽  
Qin Shi ◽  
Xin Hua Zhu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Closed Loop ◽  
Tuning Fork ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Closed Loop System ◽  
Damping Force ◽  
Analysis And Design ◽  
Vibratory Gyroscope ◽  
The Stability

The principle of drive closed-loop for tuning fork comb MEMS vibratory gyroscope is analyzed. The core of the closed-loop is to keep the vibration speed stable by adding driving force offset the damping force. The closed-loop with a single Automatic Gain Control (AGC) loop is chosen to maintain the vibration speed stable, and then the closed-loop with AGC is analyzed to obtain its transfer function. The transfer function simplifies the nonlinear AGC system to a linear system which is easy analyzed its parameters impacting the system. The values of two important parameters of AGC were chosen via simulation. The whole closed-loop system was simulated in SIMULINK. The circuit is built and tested in accordance with the theory of analysis and simulation. Experimental results demonstrate that the stability of the amplitude of vibration speed is 90ppm; and that of the frequency of vibration speed is 114ppm.

Lateral Tire Forces on Wet Roads

1977 ◽  
Vol 5 (2) ◽  
pp. 75-82 ◽  
Author(s):  
A. Schallamach
Keyword(s):  
Normal Load ◽  
The Self ◽  
Experimental Results ◽  
Slip Angle ◽  
Tire Model ◽  
Side Force ◽  
Tire Forces

Abstract Expressions are derived for side force and self-aligning torque of a simple tire model on wet roads with velocity-dependent friction. The results agree qualitatively with experimental results at moderate speeds. In particular, the theory correctly predicts that the self-aligning torque can become negative under easily realizable circumstances. The slip angle at which the torque reverses sign should increase with the normal load.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

Adaptive attitude-tracking control of spacecraft considering on-orbit refuelling

2020 ◽  
pp. 014233122097313
Author(s):  
Yiqi Xu
Keyword(s):  
Tracking Control ◽  
Closed Loop ◽  
Closed Loop System ◽  
Tracking Errors ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Inertia Model ◽  
And Performance ◽  
Attitude Tracking Control ◽  
The Stability

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.

scholarly journals Super-Twisting Algorithm Applied to Velocity Control of DC Motor without Mechanical Sensors Dependence

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6041
Author(s):  
Fredy A. Valenzuela ◽  
Reymundo Ramírez ◽  
Fermín Martínez ◽  
Onofre A. Morfín ◽  
Carlos E. Castañeda
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Dc Motor ◽  
Experimental Results ◽  
Resistive Load ◽  
Velocity Control ◽  
Velocity Sensor ◽  
Control Scheme ◽  
Mechanical Sensors ◽  
Twisting Algorithm

A DC motor velocity control in feedback systems usually requires a velocity sensor, which increases the controller cost. Additionally, the velocity sensor used in industrial applications presents several disadvantages such as maintenance requirements and signal conditioning. In this work, we propose a robust velocity control scheme applied to a DC motor based on estimation strategies using a sliding-mode observer. This means that measurements with mechanical sensors are not required in the controller design. The proposed observer estimates the rotational velocity and load torque of the motor. The controller design applies the exact-linearization technique combined with the super-twisting algorithm to achieve robust performance in the closed-loop system. The controller validation was carried out by experimental tests using a workbench, which is composed of a control and data acquisition Digital Signal Proccessor board, a DC-DC electronic converter, an interface board for signals conditioning, and a DC electric generator connected to an adjustable resistive load. The simulation and experimental results show a significant performance of the proposed control scheme. During tests, the accuracy, robustness, and speed response on the controller were evaluated and the experimental results were compared with a classic proportional-integral controller, which uses a conventional encoder.

Research on the Performances of Self-Oscillation Linear Actuator and its Compensation

2012 ◽  
Vol 433-440 ◽  
pp. 7375-7380
Author(s):  
Fan Lin ◽  
Li Qiao ◽  
Yu Wang ◽  
Hui Liu
Keyword(s):  
Nonlinear Model ◽  
Servo System ◽  
The Self ◽  
Linear Actuator ◽  
Phase Lag ◽  
Phase Lead ◽  
The Stability ◽  
Lag Compensation

Base on constitution of the self-oscillation linear actuator which is a servo system for a gun launched missile, a nonlinear model was built. Though the experiment, the model is correct. This paper studied the stability, the self-oscillation's frequency and gain on this kind of servo system. On comparing phase-lead compensation and phase-lag compensation, the later is more suitable for this system. After testing, the lag regulator is designed for the system.

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