Coordinated Control of Space-Robots Using Angular Velocity Norm Estimation.

Cross-flow turbines have a number of potential advantages for hydrokinetic energy applications. Two novel control schemes for improving cross-flow turbine energy conversion are introduced and demonstrated through scale experiments. The first aims to alter the local flow conditions on the blades through varying blade kinematics as a function of rotational position, thus increasing beneficial fluid forcing. An established method accomplishes this by oscillating the mounting angle of the blade. Instead we proposed to vary the angular velocity of the blade as a function of azimuthal position. Optimizing this controller resulted in a 59% increase in turbine performance over standard controllers. The second control scheme operates an array of two turbines in a coordinated manner to take advantage of periodic wake structures. For a range of relative turbine positions, a parent controller maintains a constant blade position difference between turbines with the same angular velocity. For select positions, the array efficiency is shown to be greater than that of a single turbine. At the optimal position, coordinated control results in a 4% increase in array performance over uncoordinated operation. Finally, intracycle angular velocity and coordinated control schema are combined.

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Review of Vehicle Active Safety Systems and their coordinated control

Recent Patents on Mechanical Engineering ◽

10.2174/2212797613999200604155414 ◽

2020 ◽

Vol 13 ◽

Author(s):

Zixiang Zhao ◽

Xiaobin Fan

Keyword(s):

Control System ◽

Angular Velocity ◽

Control Strategy ◽

Sliding Mode ◽

Control Strategies ◽

Slip Rate ◽

Coordinated Control ◽

Active Safety ◽

Vehicle Active Safety ◽

And Control

Background: All the time, the safety of the vehicle has been valued by all the world's parties, whether it is now or in the future, the automobile safety issue is the hotspot and focus of the research by experts and scholars. The continuous increase of car ownership brings convenience to people's life and also poses a threat to people's life and property security. Vehicle active safety system is the hotspot of current research and development, which plays an important role in automobile safety. Firstly, the vehicle active safety technology and its development situation was introduced, then Ref. review was carried out about Anti-Lock Brake System (ABS), Electronic Brake force Distribution (EBD/CBC), Brake Assist System (BAS/EBA/BA), Traction Control System (TCS/ASR), Vehicle Stability Control (VSC/ESP/DSC), etc. At present, there are many patents on the control of each subsystem, but few patents on the integrated control for the active safety of vehicles. Objective: The main contents of this paper are as follows: the control strategies and methods of different active safety systems, how to improve the stability of vehicle control and ensure the effectiveness of active safety system control. It provides a reference for the development of active safety control technology and patent. Methods: Through the analysis of different control algorithms and control strategies of Anti-lock and braking force distribution systems, it is pointed out that the switching of EBD/ABS coordinated control strategy according to slip rate can make full use of slip rate and road adhesion coefficient to improve the safety of the system. For the BAS, the slip problem is solved through the combination of Mechanical Assistant Braking System (MABS) and Electronic Braking Assistant (EBA) system by measuring the distance of the vehicle ahead and the speed of the vehicle ahead. The optimal slip rate control is realized by different control algorithms and control strategies of traction control system. It is pointed out that the adaptive fuzzy neural controller should be used to control the yaw angular velocity and centroid side angle of Electronic Stability Program (ESP), which has a good effect on maintaining vehicle stability. A sliding mode variable structure controller combined with constant speed control and approach law control is used to control the yaw moment. Results: Through the coordinated control strategy of EBD/ABS, the slip rate and road adhesion coefficient were fully utilized by switching according to slip rate. The problem of sliding slope is solved by MABS with EBA system. The ESP should use adaptive fuzzy neural controller to control the yaw angular velocity and centroid side angle, and adopt the joint sliding mode variable structure controller which combines the ABS control and the yaw moment control. Through the optimal control theory, the coordinated control of each subsystem can significantly improve the driving stability, riding comfort, fuel economy and so on. Conclusion: This adopt different control strategy and control algorithm for different active safety control system and make full use of tire-road friction coefficient and slip ratio optimal slip ratio, then it realized accurate control of control variables such as yawing angular velocity, centroid side-slip angle, yawing moment and finally ensure the vehicle braking stability, robustness of the controller and the lateral stability of vehicle.

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Coordinated Control of Multiple Manipulators in Space Robots. (Optimization of Control Torque using a Stabilizing Arm).

Journal of the Robotics Society of Japan ◽

10.7210/jrsj.9.718 ◽

1991 ◽

Vol 9 (6) ◽

pp. 718-726 ◽

Cited By ~ 4

Author(s):

Kazuya YOSHIDA ◽

Ryo KURAZUME ◽

Yoji UMETANI

Keyword(s):

Coordinated Control ◽

Control Torque ◽

Space Robots ◽

Multiple Manipulators

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Coordinated control for free-flyer space robots

SMC 2000 Conference Proceedings. 2000 IEEE International Conference on Systems, Man and Cybernetics. 'Cybernetics Evolving to Systems, Humans, Organizations, and their Complex Interactions' (Cat. No.00CH37166) ◽

10.1109/icsmc.2000.886559 ◽

2002 ◽

Cited By ~ 3

Author(s):

M. Marchesi ◽

F. Angrilli ◽

R. Venezia

Keyword(s):

Coordinated Control ◽

Space Robots

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Zonal and tesseral harmonic perturbations of an artificial satellite

Symposium - International Astronomical Union ◽

10.1017/s0074180900105625 ◽

1966 ◽

Vol 25 ◽

pp. 323-325 ◽

Cited By ~ 1

Author(s):

B. Garfinkel

Keyword(s):

Angular Velocity ◽

Spherical Harmonics ◽

Artificial Satellite ◽

Compact Form ◽

Earth’S Rotation ◽

Earth's Rotation ◽

Secular Variations ◽

Tesseral Harmonics

The paper extends the known solution of the Main Problem to include the effects of the higher spherical harmonics of the geopotential. The von Zeipel method is used to calculate the secular variations of orderJmand the long-periodic variations of ordersJm/J2andnJm,λ/ω. HereJmandJm,λare the coefficients of the zonal and the tesseral harmonics respectively, withJm,0=Jm, andωis the angular velocity of the Earth's rotation. With the aid of the theory of spherical harmonics the results are expressed in a most compact form.

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The Analysis of Proprioception Alteration during First Five Months after Anterior Cruciate Ligament Reconstruction

Baltic Journal of Sport and Health Sciences ◽

10.33607/bjshs.v1i84.293 ◽

2018 ◽

Vol 1 (84) ◽

Author(s):

Vilma Jurevičienė ◽

Albertas Skurvydas ◽

Juozas Belickas ◽

Giedra Bušmanienė ◽

Dovilė Kielė ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Angular Velocity ◽

Knee Joint ◽

Cruciate Ligament ◽

Position Sense ◽

Joint Position Sense ◽

Joint Position ◽

Starting Position ◽

Angular Velocities ◽

Anterior Cruciate

Research background and hypothesis. Proprioception is important in the prevention of injuries as reduced proprioception is one of the factors contributing to injury in the knee joint, particularly the ACL. Therefore, proprioception appears not only important for the prevention of ACL injuries, but also for regaining full function after ACL reconstruction.Research aim. The aim of this study was to understand how proprioception is recovered four and five months after anterior cruciate ligament (ACL) reconstruction.Research methods. The study included 15 male subjects (age – 33.7 ± 2.49 years) who had undergone unilateral ACL reconstruction with a semitendinosus/gracilis (STG) graft in Kaunas Clinical Hospital. For proprioceptive assessment, joint position sense (JPS) was measured on both legs using an isokinetic dynamometer (Biodex), at knee flexion of 60° and 70°, and at different knee angular velocities of 2°/s and 10°/s. The patients were assessed preoperatively and after 4 and 5 months, postoperatively.Research results. Our study has shown that the JPS’s (joint position sense) error scores to a controlled active movement is significantly higher in injured ACL-deficient knee than in the contralateral knee (normal knee) before surgery and after four and five months of rehabilitation. After 4 and 5 months of rehabilitation we found significantly lower values in injured knees compared to the preoperative data. Our study has shown that in injured knee active angle reproduction errors after 4 and 5 months of rehabilitation were higher compared with the ones of the uninjured knee. Proprioceptive ability on the both legs was independent of all differences angles for target and starting position for movement. The knee joint position sense on both legs depends upon the rate of two different angular velocities and the mean active angle reproduction errors at the test of angular velocity slow speed was the highest compared with the fast angular velocity. Discussion and conclusions. In conclusion, our study shows that there was improvement in mean JPS 4 and 5 months after ACL reconstruction, but it did not return to normal indices.Keywords: knee joint, joint position sense, angular velocity, starting position for movement.

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Effect of Inner and Outer Wheels Driving Force Control on Small Electric Vehicle

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.4.2020.02.0622 ◽

2020 ◽

Vol 17 (4) ◽

pp. 8246-8254

Author(s):

K. Shibazaki ◽

H. Nozaki

Keyword(s):

Control System ◽

Angular Velocity ◽

Electric Vehicle ◽

Force Constant ◽

Force Control ◽

Driving Force ◽

Vehicle Control ◽

Steering Angle ◽

Force Control System ◽

The Difference

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity, that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.

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