Combining Two Control Techniques for the Fast Movement of a Two-Wheel Mobile Robot

Control of two-wheel mobile robots (TWMRs) is quite a challenging subject for researchers and educators. Control performance of TWMRs is to satisfy both stable balancing and position tracking simultaneously. When the TWMR is moving fast in forward direction with a proportional-derivative (PD) control method, fast movement to the desired position can be achieved. However, larger oscillations in both the balancing angle and position occur. The time-delayed control (TDC) method reduces the oscillation, but its response is relatively slow. The goal of this paper is to provide a solution to satisfy both stable balancing and position for fast forward movements. This paper presents a control fusion approach between a PD control method and a TDC method to make the performance better. Two controllers are fused together with different weighting factors on the basis of a sigmoidal function to satisfy the control performance. Experimental studies are conducted to validate the proposed control approach.

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Balancing Control of a Mobile Manipulator with Two Wheels by an Acceleration-Based Disturbance Observer

International Journal of Humanoid Robotics ◽

10.1142/s0219843618500056 ◽

2018 ◽

Vol 15 (03) ◽

pp. 1850005 ◽

Cited By ~ 3

Author(s):

Yeong-Geol Bae ◽

Seul Jung

Keyword(s):

Disturbance Observer ◽

Degrees Of Freedom ◽

Control Method ◽

Experimental Studies ◽

Service Robot ◽

Mobile Manipulator ◽

Control Performance ◽

Six Degrees Of Freedom ◽

Inertia Model ◽

Balancing Control

This paper presents the balancing control performance of a mobile manipulator built in the laboratory as a service robot called Korean robot worker (KOBOKER). The robot is designed and implemented with two wheels as a mobile base and two arms with six degrees-of-freedom each. Kinematics and dynamics of the robot are analyzed. For the balancing control performance, two wheels are controlled independently by the time-delayed control method based on the inertia model of the robot. The acceleration information obtained directly from the sensor is used for the modified disturbance observer structure called an acceleration-based disturbance observer (AbDOB). Experimental studies of the balancing control of the robot are conducted to compare the control performances by both a PID control method and an AbDOB.

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SDRE based Leader-Follower Formation Control of Multiple Mobile Robots

TEMA (São Carlos) ◽

10.5540/tema.2014.015.02.0195 ◽

2014 ◽

Vol 15 (2) ◽

Author(s):

Caio Igor Gonçalves Chinelato ◽

L.S. Martins-Filho

Keyword(s):

Mobile Robots ◽

Formation Control ◽

Control Method ◽

Nonlinear Dynamical System ◽

Control Performance ◽

Font Size ◽

Multiple Mobile Robots ◽

Nonlinear Dynamical ◽

Control Techniques ◽

State Dependent

Formation control of multiple mobile robots is relatively a new area of robotics and increase the control performance and advantages of multiple mobile robots systems. <a name="OLE_LINK72">In this work we present a study concerning the modeling and formation control of a robotic system composed by two mobile robots, where one robot is the leader and the other is follower</a>. The system is a nonlinear dynamical system and cannot be controlled by traditional linear control techniques. The control strategy proposed is the SDRE (State-Dependent Riccati Equation) method. Simulations results with the software Matlab show the efficiency of the control method.

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An Adaptive Evolutionary Switching Control for Robot Manipulators

Volume 7: 29th Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2005-84333 ◽

2005 ◽

Author(s):

P. R. Ouyang ◽

W. J. Zhang ◽

Madan M. Gupta

Keyword(s):

Trajectory Tracking ◽

Control Method ◽

Robot Manipulators ◽

Industrial Robot ◽

Switching Control ◽

Learning Ability ◽

Pd Control ◽

Control Approach ◽

Gain Switching ◽

Control Scheme

In this paper, a new adaptive switching control approach, called adaptive evolutionary switching PD control (AES-PD), is proposed for iterative operations of robot manipulators. The proposed AES-PD control method is a combination of the feedback of PD control with gain switching and feedforward using the input torque profile obtained from the previous iteration. The asymptotic convergence of the AES-PD control method is theoretically proved using Lyapunov’s method. The philosophy of the switching control strategy is interpreted in the context of the iteration domain to increase the speed of the convergence for trajectory tracking of robot manipulators. The AES-PD control has a simple control structure that makes it easily implemented. The validity of the proposed control scheme is demonstrated for the trajectory tracking of robot manipulators through simulation studies. Simulation results show that the AES-PD control can improve the tracking performance with an increase of the iteration number. The EAS-PD control method has the adaptive and learning ability; therefore, it should be very attractive to applications of industrial robot control.

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One-Dimensional Contact Pressure Distribution of Radial Tires in Motion

Tire Science and Technology ◽

10.2346/1.2137498 ◽

1995 ◽

Vol 23 (2) ◽

pp. 116-135 ◽

Cited By ~ 9

Author(s):

H. Shiobara ◽

T. Akasaka ◽

S. Kagami ◽

S. Tsutsumi

Keyword(s):

Pressure Distribution ◽

Contact Pressure ◽

Experimental Studies ◽

Rolling Resistance ◽

Leading Edge ◽

Forward Direction ◽

Contact Pressure Distribution ◽

Support Ring ◽

One Dimensional ◽

Lowered Pressure

Abstract The contact pressure distribution and the rolling resistance of a running radial tire under load are fundamental properties of the tire construction, important to the steering performance of automobiles, as is well known. Many theoretical and experimental studies have been previously published on these tire properties. However, the relationships between tire performances in service and tire structural properties have not been clarified sufficiently due to analytical and experimental difficulties. In this paper, establishing a spring support ring model made of a composite belt ring and a Voigt type viscoelastic spring system of the sidewall and the tread rubber, we analyze the one-dimensional contact pressure distribution of a running tire at speeds of up to 60 km/h. The predicted distribution of the contact pressure under appropriate values of damping coefficients of rubber is shown to be in good agreement with experimental results. It is confirmed by this study that increasing velocity causes the pressure to rise at the leading edge of the contact patch, accompanied by the lowered pressure at the trailing edge, and further a slight movement of the contact area in the forward direction.

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ICMA: AN EFFICIENT INTEGRATED CONGESTION CONTROL APPROACH

Recent Patents on Engineering ◽

10.2174/1872212114666191231150916 ◽

2019 ◽

Vol 14 ◽

Author(s):

Tayyab Khan ◽

Karan Singh ◽

Kamlesh C. Purohit

Keyword(s):

Congestion Control ◽

Packet Loss ◽

Control Method ◽

Multicast Communication ◽

Bandwidth Utilization ◽

File Transfer ◽

Control Approach ◽

Communication Technique ◽

Control Scheme ◽

Multiparty Video Conferencing

Background: With the growing popularity of various group communication applications such as file transfer, multimedia events, distance learning, email distribution, multiparty video conferencing and teleconferencing, multicasting seems to be a useful tool for efficient multipoint data distribution. An efficient communication technique depends on the various parameters like processing speed, buffer storage, and amount of data flow between the nodes. If data exceeds beyond the capacity of a link or node, then it introduces congestion in the network. A series of multicast congestion control algorithms have been developed, but due to the heterogeneous network environment, these approaches do not respond nor reduce congestion quickly whenever network behavior changes. Objective: Multicasting is a robust and efficient one-to-many (1: M) group transmission (communication) technique to reduced communication cost, bandwidth consumption, processing time and delays with similar reliability (dependability) as of regular unicast. This patent presents a novel and comprehensive congestion control method known as integrated multicast congestion control approach (ICMA) to reduce packet loss. Methods: The proposed mechanism is based on leave-join and flow control mechanism along with proportional integrated and derivate (PID) controller to reduce packet loss, depending on the congestion status. In the proposed approach, Proportional integrated and derivate controller computes expected incoming rate at each router and feedback this rate to upstream routers of the multicast network to stabilize their local buffer occupancy. Results: Simulation results on NS-2 exhibit the immense performance of the proposed approach in terms of delay, throughput, bandwidth utilization, and packet loss than other existing methods. Conclusion: The proposed congestion control scheme provides better bandwidth utilization and throughput than other existing approaches. Moreover, we have discussed existing congestion control schemes with their research gaps. In the future, we are planning to explore the fairness and quality of service issue in multicast communication.

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A Critical Review of Supersonic Flow Control for High-Speed Applications

Applied Sciences ◽

10.3390/app11156899 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6899

Author(s):

Abdul Aabid ◽

Sher Afghan Khan ◽

Muneer Baig

Keyword(s):

Supersonic Flow ◽

Flow Control ◽

Active Control ◽

Critical Review ◽

High Speed ◽

Passive Control ◽

Control Method ◽

Sudden Expansion ◽

Control Approach ◽

Cost Efficient

In high-speed fluid dynamics, base pressure controls find many engineering applications, such as in the automobile and defense industries. Several studies have been reported on flow control with sudden expansion duct. Passive control was found to be more beneficial in the last four decades and is used in devices such as cavities, ribs, aerospikes, etc., but these need additional control mechanics and objects to control the flow. Therefore, in the last two decades, the active control method has been used via a microjet controller at the base region of the suddenly expanded duct of the convergent–divergent (CD) nozzle to control the flow, which was found to be a cost-efficient and energy-saving method. Hence, in this paper, a systemic literature review is conducted to investigate the research gap by reviewing the exhaustive work on the active control of high-speed aerodynamic flows from the nozzle as the major focus. Additionally, a basic idea about the nozzle and its configuration is discussed, and the passive control method for the control of flow, jet and noise are represented in order to investigate the existing contributions in supersonic speed applications. A critical review of the last two decades considering the challenges and limitations in this field is expressed. As a contribution, some major and minor gaps are introduced, and we plot the research trends in this field. As a result, this review can serve as guidance and an opportunity for scholars who want to use an active control approach via microjets for supersonic flow problems.

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A New Torque Distribution Control for Four-Wheel Independent-Drive Electric Vehicles

Actuators ◽

10.3390/act10060122 ◽

2021 ◽

Vol 10 (6) ◽

pp. 122

Author(s):

Dejun Yin ◽

Junjie Wang ◽

Jinjian Du ◽

Gang Chen ◽

Jia-Sheng Hu

Keyword(s):

Electric Vehicles ◽

Vehicle Stability ◽

Hardware In The Loop ◽

Control Performance ◽

Torque Distribution ◽

Handling Performance ◽

Control Approach ◽

Tire Forces ◽

Yaw Moment ◽

New Distribution

Torque distribution control is a key technique for four-wheel independent-drive electric vehicles because it significantly affects vehicle stability and handling performance, especially under extreme driving conditions. This paper, which focuses on the global yaw moment generated by both the longitudinal and the lateral tire forces, proposes a new distribution control to allocate driving torques to four-wheel motors. The proposed objective function not only minimizes the longitudinal tire usage, but also make increased use of each tire to generate yaw moment and achieve a quicker yaw response. By analysis and a comparison with prior torque distribution control, the proposed control approach is shown to have better control performance in hardware-in-the-loop simulations.

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The Influence of Genetics in Myopia Control: A Pilot Study

Journal of Clinical Medicine ◽

10.3390/jcm10040808 ◽

2021 ◽

Vol 10 (4) ◽

pp. 808

Author(s):

Cristina Alvarez-Peregrina ◽

Miguel Ángel Sánchez-Tena ◽

Clara Martinez-Perez ◽

Catalina Santiago-Dorrego ◽

Thomas Yvert ◽

...

Keyword(s):

Pilot Study ◽

Treatment Response ◽

Axial Length ◽

Contact Lenses ◽

Control Method ◽

Saliva Sample ◽

Experimental Studies ◽

Strong Linkage Disequilibrium ◽

Student’S T ◽

Myopia Control

Background: Many epidemiological and experimental studies have established that myopia is caused by a complex interaction between common genetic and environmental factors. The objective of this study was to describe and compare the allelic and genotypic frequencies of the rs524952 (GJD2), rs8000973 (ZIC2), rs1881492 (CHRNG), rs1656404 (PRSS56), rs235770 (BMP2), and rs7744813 (KCNQ5) SNPs (single-nucleotide polymorphism) between responder and nonresponder patients who had undergone a two-year treatment with lenses for myopia control. Method: Twenty-eight participants from the MiSight Assessment Study Spain (MASS), who had received treatment for myopia control for two years with MiSight contact lenses, were examined. The criteria for better/worse treatment response was the change in the axial length (< / ≥ 0.22 mm two years after the treatment). The clinical procedure consisted of the extraction of a saliva sample, and the participants also underwent an optometric examination. Genetic data were analyzed using SNPStats software (Catalan Institute of Oncology, Barcelona, Spain), and statistical analysis was performed using SPSS v.25 (SPSS Inc., Chicago, IL, USA). Demographic variables were analyzed using the Student’s t-test. Results: The T allele, the one with the lowest frequency, of the “rs235770” SNP was associated with a better treatment response [AL/CR (axial length/corneal radius): OR = 3.37; CI = 1.079–10.886; SE (spherical equivalent): OR = 1.26; CI: = 0.519–57.169; p = 0.019). By performing haplotype analysis, significant differences were found between the rs235770…rs1881492 and rs235770–rs1656404 polymorphisms. The latter presented a strong linkage disequilibrium with each other (r2 ≥ 0.54). Conclusion: The result of lens therapies for myopia control could vary depending on genetic variants. Studies with a larger sample are needed to confirm the results presented in this pilot study.

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A Novel Adaptive Control Approach Based on Available Headroom of the VSC-HVDC for Enhancement of the AC Voltage Stability

Energies ◽

10.3390/en14113222 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3222

Author(s):

Duc Nguyen Huu

Keyword(s):

Adaptive Control ◽

Voltage Stability ◽

Reactive Power ◽

Control Method ◽

Offshore Wind ◽

Voltage Source ◽

Long Distance ◽

Control Approach ◽

Hvdc System ◽

Voltage Support

Increasing offshore wind farms are rapidly installed and planned. However, this will pose a bottle neck challenge for long-distance transmission as well as inherent variation of their generating power outputs to the existing AC grid. VSC-HVDC links could be an effective and flexible method for this issue. With the growing use of voltage source converter high-voltage direct current (VSC-HVDC) technology, the hybrid VSC-HVDC and AC system will be a next-generation transmission network. This paper analyzes the contribution of the multi VSC-HVDC system on the AC voltage stability of the hybrid system. A key contribution of this research is proposing a novel adaptive control approach of the VSC-HVDC as a so-called dynamic reactive power booster to enhance the voltage stability of the AC system. The core idea is that the novel control system is automatically providing a reactive current based on dynamic frequency of the AC system to maximal AC voltage support. Based on the analysis, an adaptive control method applied to the multi VSC-HVDC system is proposed to realize maximum capacity of VSC for reactive power according to the change of the system frequency during severe faults of the AC grid. A representative hybrid AC-DC network based on Germany is developed. Detailed modeling of the hybrid AC-DC network and its proposed control is derived in PSCAD software. PSCAD simulation results and analysis verify the effective performance of this novel adaptive control of VSC-HVDC for voltage support. Thanks to this control scheme, the hybrid AC-DC network can avoid circumstances that lead to voltage instability.

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Lifetime and reliability improvements in modular multilevel converters using controlled circulating current

Journal of Power Electronics ◽

10.1007/s43236-021-00297-7 ◽

2021 ◽

Author(s):

Nasiru B. Kadandani ◽

Mohamed Dahidah ◽

Salaheddine Ethni ◽

Musbahu Muhammad

Keyword(s):

Control Method ◽

Semiconductor Devices ◽

Junction Temperature ◽

Multilevel Converters ◽

Control Approach ◽

Circulating Current ◽

Inherent Feature ◽

Modular Multilevel Converters ◽

Current Loading ◽

Laboratory Prototype

AbstractCirculating current has been an inherent feature of modular multilevel converters (MMC), which results in second-order harmonics on the arms currents. If not properly controlled, the circulating current can affect the lifetime and reliability of a converter by increasing the current loading, loss distribution, and junction temperature of its semiconductor devices. This paper proposes controlled circulating current injection as a means of improving the lifetime and reliability of an MMC. The proposed method involves modifying the reference modulating signals of the converter arms to include the controlled differential voltage as an offset. The junction temperature of the semiconductor devices obtained from an electro-thermal simulation is processed to deduce the lifetime and reliability of the converter. The obtained results are benchmarked against a case where the control method is not incorporated. The incorporation of the proposed control method results in a 68.25% increase in the expected lifetime of the converter and a 3.06% increase on its reliability index. Experimental results of a scaled down laboratory prototype validate the effectiveness of the proposed control approach.

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