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20 pages, 2223 KiB

Open AccessArticle

Disturbance Robust Attitude Stabilization of Multirotors with Control Moment Gyros

by Youyoung Yang, Sungsu Kim, Kwanghyun Lee and Henzeh Leeghim

Sensors 2024, 24(24), 8212; https://doi.org/10.3390/s24248212 - 23 Dec 2024

Cited by 4 | Viewed by 861

This paper presents a novel control framework for enhancing the attitude stabilization of multirotor UAVs using Control Moment Gyros (CMGs) and a Disturbance Robust Drive Law (DRDL). Due to their lightweight and compact structure, multirotor UAVs are highly susceptible to disturbances such as wind, making it challenging to achieve stable attitude control using rotor thrust alone. To address this issue, we employ CMGs to provide robust attitude control and apply Fast Terminal Sliding Mode Control (FTSMC) to ensure fast and accurate convergence within a finite time. The combination of CMGs’ torque amplification capability with the DRDL enables the system to effectively avoid singularities and maintain stable control performance in the presence of disturbances. Simulation results demonstrate that the CMG-equipped hexarotor utilizing the DRDL rapidly converges to the target attitude despite external disturbances, while minimizing oscillations in both motor speed and gimbal movement. Additionally, compared to the pseudo-inverse control method, the proposed approach significantly improves singularity avoidance and disturbance mitigation. The proposed control framework enhances the stability and reliability of UAV operations and demonstrates its potential for high-performance control in challenging disturbance environments. Full article

(This article belongs to the Section Remote Sensors)

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33 pages, 6190 KiB

Open AccessArticle

Practical System Identification and Incremental Control Design for a Subscale Fixed-Wing Aircraft

by Rasmus Steffensen, Kilian Ginnell and Florian Holzapfel

Actuators 2024, 13(4), 130; https://doi.org/10.3390/act13040130 - 4 Apr 2024

Cited by 7 | Viewed by 2883

Abstract

An incremental differential proportional integral (iDPI) control law using eigenstructure assignment gain design is tested in flight on a subscale platform to validate its suitability for fixed-wing flight control. A kinematic relation for the aerodynamic side-slip angle rate is developed to apply a pseudo full state feedback. In order to perform the gain design and assessment, a plant model is estimated using flight test data from gyro, accelerometer, airspeed and surface deflection measurements during sine-sweep excitations. Transfer function models for the actuators and surface deflections are identified both in-flight and on the ground for several different actuators and control surfaces using hall sensor surface deflection measurements. The analysis reveals a large variation in bandwidth between the different types of servo motors. Flight test results are presented which demonstrates that the plant model estimates based on tests with good frequency excitation, high bandwidth actuators and surface deflection measurements can be used to reasonably predict the closed-loop dynamic behavior of the aircraft. The closed-loop flight test results of the iDPi control law show good performance and lays the groundwork for further development. Full article

(This article belongs to the Special Issue From Theory to Practice: Incremental Nonlinear Control)

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23 pages, 8250 KiB

Open AccessArticle

Gyro-Sensor-Based Vibration Control for Dynamic Humanoid-Robot Walking on Inclined Surfaces

by Sunandan Dutta, Mitiko Miura-Mattausch, Yoshihiro Ochi, Naoto Yorino and Hans Jürgen Mattausch

Sensors 2020, 20(24), 7139; https://doi.org/10.3390/s20247139 - 12 Dec 2020

Cited by 4 | Viewed by 5465

Abstract

An efficient motor-control system for stable walking of the lightweight humanoid robot KONDO KHR-3HV on inclined surfaces is investigated. The motor-control system is based on the angular velocity of the pitch motion of the robot, which is detected by a gyro sensor attached to the robot torso and referred to as the angular-pitch velocity. The robot gait is analyzed for different downslopes with and without the motor-feedback control. A novel method of frequency-domain analysis of the angular-pitch velocity is proposed for explaining the reasons behind the instabilities of dynamic humanoid-robot walking on inclined surfaces. The results show, that a nonlinear nature of the motor torque, due to a force induced by the slope, gives rise to harmonics of the fundamental walking frequency of 1.73 Hz. These harmonics are the origin of the unstable robot walking. Additionally, the feedback-gain parameters K_A and K_H affect the amplitudes of the harmonics, which give rise to vibrations at a higher surface inclination. Increased surface friction allows a reduction of the feedback gain, which reduces this specific contribution to the harmonics and thus stabilizes the robot. To improve the walking stability on inclined surfaces, it is found that the damped natural frequency of the motor-control system must be kept lower than the fundamental walking frequency. Full article

(This article belongs to the Collection Sensors in Biomechanics)

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21 pages, 2942 KiB

Open AccessArticle

Gyro Motor State Evaluation and Prediction Using the Extended Hidden Markov Model

by Lei Dong, Jianfei Wang, Ming-Lang Tseng, Zhiyong Yang, Benfu Ma and Ling-Ling Li

Symmetry 2020, 12(11), 1750; https://doi.org/10.3390/sym12111750 - 22 Oct 2020

Cited by 4 | Viewed by 2101

Abstract

This study extracted the featured vectors in the same way from testing data and substituted these vectors into a trained hidden Markov model to get the log likelihood probability. The log likelihood probability was matched with the time–probability curve from where the gyro motor state evaluation and prediction were realized. A core component of gyroscopes is linked to the reliability of the inertia system to conduct gyro motor state evaluation and prediction. This study features the vectors’ extraction from full life cycle gyro motor data and completes the training model to feature the vectors according to the time sequence and extraction to full life cycle data undergoing hidden Markov model training. This proposed model applies to full life cycle gyro motor data for validation, compared with traditional hidden Markov model predictive methods and health condition-trained data. The results suggest precise evaluation and prediction and provide an important basis for gyro motor repair and replacement strategies. Full article

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12 pages, 4007 KiB

Open AccessArticle

Accelerometer-Based Gyroscope Drift Compensation Approach in a Dual-Axial Stabilization Platform

by Shutong Li, Yanbin Gao, Gong Meng, Gang Wang and Lianwu Guan

Electronics 2019, 8(5), 594; https://doi.org/10.3390/electronics8050594 - 27 May 2019

Cited by 12 | Viewed by 9393

Abstract

An accelerometer-based gyro drift compensation approach in a dual-axial stabilization platform is introduced in this paper. The stabilization platform consists of platform framework, drive motor, gyro and accelerometer module and contorl board. Gyro is an angular rate detecting element to achieve angular rate and rotation angle of the dynamic platform system. However, the platform system has an unstable factor because of the drift of gyro. The main contribution of this paper is to implement a convenient gyro drift compensation approach by using the accelerometer. In contrast to a kalman filtering method, this approach is simpler and practical due to the high-precision characteristic of the accelerometer. Data filtering algorithm and limit of threshold setting of total acceleration values are applied in this approach. The validity and feasibility of the proposed approach are evaluated by four tests under various conditions. Full article

(This article belongs to the Section Microelectronics)

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19 pages, 3708 KiB

Open AccessArticle

High-Precision Speed Control Based on Multiple Phase-Shift Resonant Controllers for Gimbal System in MSCMG

by Jian Feng, Qing Wang and Kun Liu

Energies 2018, 11(1), 32; https://doi.org/10.3390/en11010032 - 1 Jan 2018

Cited by 13 | Viewed by 4414

Abstract

The high precision speed control of gimbal servo system in magnetically suspended control moment gyro (MSCMG) suffers from periodic torque disturbances, which lead to periodic fluctuations in speed control. This paper proposes a novel multiple phase-shift resonant controller (MPRC) for a gimbal servo system to suppress the periodic torque ripples whose frequencies vary with the operational speed of the gimbal servo motor and high-speed motor. First, the periodic torque ripples caused by cogging torque, flux harmonics and the dynamic unbalance of the high speed rotor are analyzed. Second, the principle and structure of MPRC parallel with proportional integral (PI) controllers are discussed. The design and stability analysis of the proposed MPRC plus PI control scheme are given both for the current loop and speed loop. The closed-loop stability is ensured by adjusting the phase in the entire operational speed range. Finally, the effectiveness of the proposed control method is verified through simulation and experimental results. Full article

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5 pages, 2314 KiB

Open AccessArticle

Researches and Development of an Efficient Electric PersonalMover for City Commuters

by Sijia Cao, Yagang Huang, Youtong Zhang, Dong Zhao and Ke Liu

World Electr. Veh. J. 2010, 4(2), 238-242; https://doi.org/10.3390/wevj4020238 - 25 Jun 2010

Viewed by 1025

Abstract

In order to reduce the carbon emission, saving fuel energy and for the convenience of personal transportation in urban area, a two-wheel-driven self-balancing vehicle was developed, which utilize the well-known inverted pendulum control technique, can carry one person and travels at a maximum speed of 20km/h. The vehicle which is called “Tiny” ， consists up of two brushless DC motors, the motors are placed coaxially. A gravity sensor and a gyro are mounted on the vehicle, signals from the two sensors are combined with Kalman Filter to indicate the tilt angle of the vehicle. By controlling the tilt angle to be 0 degree (which means the vehicle body is perpendicular to ground), the vehicle can perform travelling forward and backward. In this paper, the implementation of the Kalman filter is discussed by using Matlab simulations, and the mathematical model of the vehicle is also presented, then the controlling diagram is presented. In the end of this paper, some experimental parameter is presented. Full article

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