scholarly journals Control Strategy for the Pseudo-Driven Wheels of Multi-Wheeled Mobile Robots Based on Dissociation by Degrees-of-Freedom

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 155477-155491
Author(s):  
Huanan Qi ◽  
Bo You ◽  
Liang Ding ◽  
Wenhao Lian ◽  
Ye Yuan ◽  
...  
Keyword(s):  
Mobile Robots ◽  
Control Strategy ◽  
Degrees Of Freedom ◽  
Wheeled Mobile Robots

HOLONOMIC AND OMNIDIRECTIONAL LOCOMOTION SYSTEMS FOR WHEELED MOBILE ROBOTS: A REVIEW

2015 ◽  
Vol 77 (28) ◽  
Author(s):  
M. Juhairi Aziz Safar
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Degrees Of Freedom ◽  
Wheeled Mobile Robot ◽  
Arbitrary Direction ◽  
Current Position ◽  
Wheeled Mobile Robots ◽  
Future Improvement ◽  
Position And Orientation ◽  
Three Degrees Of Freedom

Holonomic and omnidirectional locomotion systems are best known for their capability to maneuver at any arbitrary direction regardless of their current position and orientation with a three degrees of freedom mobility. This paper summarizes the advancement of holonomic and omnidirectional locomotion systems for wheeled mobile robot applications and discuss the issues and challenges for future improvement.

Controlled Maneuverability of an Articulated Tracked Mobile Robot

2010 ◽  
Author(s):  
Patrick Labenda ◽  
Tim Sadek ◽  
Thomas Predki
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Control Strategy ◽  
Degrees Of Freedom ◽  
Articulated Vehicles ◽  
Unstructured Environment ◽  
Translational Degree ◽  
Feedback Control Strategy ◽  
The Individual ◽  
Tracked Mobile Robot

Considerable potentials with regard to mobility in unstructured environment offer actively articulated mobile robots equipped with powered wheels or tracks. These potentials are obvious when dealing with a system’s trafficability and terrainability. However, maneuverability and steerability of articulated mobile robots are challenging. This is due to the fact that these robots represent a form of truck-trailer systems leading to interactions and influences between the individual vehicles resulting in significant problems like e.g. off-tracking with regard to a given path. Further on, when dealing with a mobile robot’s maneuverability there are only few scientific contributions covering articulated vehicles with actively powered trailers using tracks as propulsive elements. The described systems differ significantly with regard to their configuration with respect to the multi-redundant mobile robot in this work. To investigate the maneuverability of articulated tracked mobile robots a demonstrator has been developed. It is built up out of three identical modules which are connected with each other in a rowby means of a rotational and a translational degree-of-freedom. Each module has two tracks which can be powered independently. Overall, the system has got ten degrees-of-freedom whereas six of them are active and four passive. The developed demonstrator has been used for investigations dealing with maneuverability and steerability as well as modularization of the system’s control architecture. The paper summarizes the development of the mobile robot, its feedback control strategy as well as the tests carried out. The achieved results show a satisfying performance with regard to the implemented control strategy and the system’s maneuverability.

scholarly journals Design and Fabrication of Rocker Bogie Mechanism

2021 ◽  
Vol 9 (VI) ◽  
pp. 1033-1037
Author(s):  
Mayank Tamgadge
Keyword(s):  
Mobile Robots ◽  
Control Strategy ◽  
High Speed ◽  
Wheeled Mobile Robots ◽  
Support Design ◽  
Average Speed ◽  
Design Structure ◽  
Different Types ◽  
The Stability ◽  
Step Over

The rocker-bogie suspension mechanism its currently NASAs one of the favourite design for wheeled mobile robots, mainly because it has multipurpose capabilities to deal with different types of surface and obstacles because it uniformly distributes the overall weight over its 6 wheels at all times. That's why it has many advantages when dealing with obstacles, there is one of the disadvantage is its low average speed of operation, the rocker bogie system generally not suitable for situations where high-speed operations for which to cover large surfaces Areas. mainly due to stability problems. Our purpose is to increase the stability of the rocker-bogie mechanism system by expanding its support design structure, making it more stable and flexible while moving at high speed, at different surfaces but keeping its original flexibility against obstacles. Most of the flexibility of this method can be achieved without any mechanical modification to existing designs only a change in control strategy. Some mechanical changes are required to Achieve the maximum Advantages and to increase the rover operations speed in future. We will develop a method of driving a rocker-bogie vehicle so that it can effectively step over most obstacles rather than impacting and climbing over them. The Rocker-Bogie Mechanism system was designed to be used at slow speeds. It is capable of overcoming obstacles that are depends upon the size of a wheel.

scholarly journals Torque Ripple Suppression of PMSM Based on Robust Two Degrees-of-Freedom Resonant Controller

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1015
Author(s):  
Mingfei Huang ◽  
Yongting Deng ◽  
Hongwen Li ◽  
Jing Liu ◽  
Meng Shao ◽  
...  
Keyword(s):  
Control Strategy ◽  
Measurement Errors ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Torque Ripple ◽  
Current Loop ◽  
Two Degrees Of Freedom ◽  
Robust Stability Analysis ◽  
Resonant Controller ◽  
Testing Environments

This paper concentrates on a robust resonant control strategy of a permanent magnet synchronous motor (PMSM) for electric drivers with model uncertainties and external disturbances to improve the control performance of the current loop. Firstly, to reduce the torque ripple of PMSM, the resonant controller with fractional order (FO) calculus is introduced. Then, a robust two degrees-of-freedom (Robust-TDOF) control strategy was designed based on the modified resonant controller. Finally, by combining the two control methods, this study proposes an enhanced Robust-TDOF regulation method, named as the robust two degrees-of-freedom resonant controller (Robust-TDOFR), to guarantee the robustness of model uncertainty and to further improve the performance with minimized periodic torque ripples. Meanwhile, a tuning method was constructed followed by stability and robust stability analysis. Furthermore, the proposed Robust-TDOFR control method was applied in the current loop of a PMSM to suppress the periodic current harmonics caused by non-ideal factors of inverter and current measurement errors. Finally, simulations and experiments were performed to validate our control strategy. The simulation and experimental results showed that the THDs (total harmonic distortion) of phase current decreased to a level of 0.69% and 5.79% in the two testing environments.

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