scholarly journals Formation Tracking of Heterogeneous Mobile Agents Using Distance and Area Constraints

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
E. G. Hernandez-Martinez ◽  
E. D. Ferreira-Vazquez ◽  
G. Fernandez-Anaya ◽  
J. J. Flores-Godoy
Keyword(s):  
Control Strategy ◽  
Mobile Agents ◽  
Tracking Control ◽  
Control Strategies ◽  
Local Information ◽  
Control Laws ◽  
Formation Tracking ◽  
Communication Topology ◽  
Signed Area ◽  
Double Integrator

This paper presents two formation tracking control strategies for a combined set of single and double integrator agents with an arbitrary undirected communication topology. The first approach is based on the design of distance-based potential functions with interagent collision avoidance using local information about the distance and orientation between agents and the desired trajectory. The second approach adds signed area constraints to the desired formation specification and a control strategy that uses distance as well as area terms is designed to achieve tracking convergence. Numerical simulations show the performance from both control laws.

scholarly journals Formation Tracking Control and Obstacle Avoidance of Unicycle-Type Robots Guaranteeing Continuous Velocities

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4374
Author(s):  
Jose Bernardo Martinez ◽  
Hector M. Becerra ◽  
David Gomez-Gutierrez
Keyword(s):  
Obstacle Avoidance ◽  
Tracking Control ◽  
Global Coordinate System ◽  
Avoidance Task ◽  
Time Varying ◽  
Control Laws ◽  
Formation Tracking ◽  
Control Scheme ◽  
First Time ◽  
Hierarchical Scheme

In this paper, we addressed the problem of controlling the position of a group of unicycle-type robots to follow in formation a time-varying reference avoiding obstacles when needed. We propose a kinematic control scheme that, unlike existing methods, is able to simultaneously solve the both tasks involved in the problem, effectively combining control laws devoted to achieve formation tracking and obstacle avoidance. The main contributions of the paper are twofold: first, the advantages of the proposed approach are not all integrated in existing schemes, ours is fully distributed since the formulation is based on consensus including the leader as part of the formation, scalable for a large number of robots, generic to define a desired formation, and it does not require a global coordinate system or a map of the environment. Second, to the authors’ knowledge, it is the first time that a distributed formation tracking control is combined with obstacle avoidance to solve both tasks simultaneously using a hierarchical scheme, thus guaranteeing continuous robots velocities in spite of activation/deactivation of the obstacle avoidance task, and stability is proven even in the transition of tasks. The effectiveness of the approach is shown through simulations and experiments with real robots.

scholarly journals Research on multidimensional evaluation of tracking control strategies for self-driving vehicles

2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091296 ◽  
Author(s):  
Yuan-yuan Ren ◽  
Jie Wang ◽  
Xue-lian Zheng ◽  
Qi-chao Zhao ◽  
Jia-lei Ma ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Feedback Control ◽  
Control Strategy ◽  
Tracking Control ◽  
Evaluation System ◽  
Feedforward Control ◽  
Control Strategies ◽  
Dynamic Feedback ◽  
Multidimensional Evaluation ◽  
Control Dynamic

Performance evaluation is a necessary stage in development of tracking control strategy of autonomous vehicle system, which determines the scope of application and promotes further improvement. At present, most of the tracking control strategies include performance evaluation. However, performance evaluation criteria differ from work to work, lacking comprehensive evaluation system. This article proposes a multidimensional integrated tracking control evaluation system based on subjective and objective weighting, taking into account the tracking accuracy, driving stability, and ride comfort. Through the co-simulation of CarSim and Simulink, qualitative analysis and quantitative analysis based on multidimensional evaluation system of five coupled longitudinal and lateral control strategies (lateral: pure pursuit feedforward control, dynamic-model-based optimal curvature control (dynamic feedforward control), Stanley feedback control, kinematics feedback control, and dynamic feedback control; longitudinal: the incremental proportion–integration–differentiation control) under typical operating conditions are carried out to analyze the operating range and robustness of each tracking control strategy. The results show that the Stanley tracking control strategy and the dynamic feedback tracking control strategy have a wide range of applications and robustness. The consistency of qualitative analysis results and the quantitative analysis results verify the validity and feasibility of the evaluation system.

ZMP Tracking Control of an Android Robot Leg on Slope-Changing Ground Using Disturbance Observer and Dual Plant Models

2016 ◽  
Vol 13 (03) ◽  
pp. 1550043 ◽  
Author(s):  
Jung-Yup Kim ◽  
Young-Seog Kim
Keyword(s):  
Control Strategy ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Balance Control ◽  
Control Strategies ◽  
Center Of Mass ◽  
Model Inversion ◽  
Slope Change ◽  
Ground Slope ◽  
Android Robot

This paper describes a novel zero moment point (ZMP) tracking control strategy using a disturbance observer (DOB) in the presence of ground slope change for balance control of an android robot. With regard to conventional ZMP controls, many researchers have studied ZMP tracking control strategies using an inverted pendulum model on flat level ground, and they have solved a slow response problem of nonminimum phase systems by using suitable feedforward motions called walking patterns. However, the conventional methods lead to ZMP offset errors in the presence of ground slope change; it is hence necessary to quickly eliminate the ZMP offset errors to realize robust balance control. In this paper, we rapidly eliminate the ZMP offset errors through a DOB using a model inversion for robust balance control in the presence of ground slope change. In particular, a dynamic model that uses the projected center of mass (CoM) position on the ground is additionally used as an output to solve a problem that generates an unstable pole during model inversion. Finally, the proposed control strategy is verified through MATLAB simulations and experiments using a real android leg.

A Uniform Control for Tracking and Point Stabilization of Differential Drive Robots Subject to Hard Input Constraints

2015 ◽  
Author(s):  
Amin Zeiaee ◽  
Rana Soltani-Zarrin ◽  
Suhada Jayasuriya ◽  
Reza Langari
Keyword(s):  
Control Strategy ◽  
Tracking Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Initial Point ◽  
Input Constraints ◽  
Unified Framework ◽  
Minimization Method ◽  
Differential Drive ◽  
Point Stabilization

This paper develops a unified framework for point stabilization and tracking control of differential drive robots under hard input constraints. The proposed control strategy is based on the recently introduced Pointwise Angle Minimization method and addresses the steering problem by studying a robot’s achievable directions of motion considering the constraints imposed on it. To illustrate the strength of the proposed framework, a new control problem which combines the posture stabilization and tracking control is studied. The problem of interest is steering a constrained-input mobile robot from an initial point towards a final point on a desired trajectory while regulating the robot’s heading such that the control convergence is guaranteed within the admissible input space. Inspired by the geometry of sliding mode control, this paper proposes a new control strategy for this problem. The stability of the closed loop system under the proposed steering scheme is proved by Lyapunov analysis for the shortest path trajectory and generalization to the case of arbitrarily chosen desired trajectory has been proposed. Finally, effectiveness of the discussed control strategies are illustrated by several simulation results.

scholarly journals Trajectory Tracking Control Design of a Mass-Damping-Spring System with Uncertainty using the Bond Graph Approach

2020 ◽  
Vol 10 (6) ◽  
pp. 6427-6431
Author(s):  
I. Dif ◽  
A. Kouzou ◽  
K. Benmahammed ◽  
A. Hafaifa
Keyword(s):  
Trajectory Tracking ◽  
Control Strategy ◽  
Tracking Control ◽  
Bond Graph ◽  
Control Law ◽  
Trajectory Tracking Control ◽  
Control Laws ◽  
Spring System ◽  
Mechanical Mass ◽  
Mass Spring

This paper deals with the simulation, and design of a trajectory-tracking control law for a physical system under parameter uncertainty modeled by a bond graph. This control strategy is based on the inversion of the system through their causal Input/Output (I/O) path using the principle of bicausality to track the desired trajectory. The proposed control strategy is validated with the use of a simple mechanical mass-spring-damper system. The results show that the bond graph is a very helpful methodology for the design of control laws in the presence of uncertainties. This proposed control can be applied in several applications and can be improved to ensure robust control.

scholarly journals Evaluation of a home-based 7-day infection control strategy for healthcare workers following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2): A cohort study

2020 ◽  
pp. 1-4
Author(s):  
Carla Benea ◽  
Laura Rendon ◽  
Jesse Papenburg ◽  
Charles Frenette ◽  
Ahmed Imacoudene ◽  
...  
Keyword(s):  
High Risk ◽  
Infection Control ◽  
Control Strategy ◽  
Healthcare Workers ◽  
Control Strategies ◽  
Risk Exposure ◽  
Nasopharyngeal Swab ◽  
Home Based ◽  
Respiratory Coronavirus ◽  
Second Wave

Abstract Objective: Evidence-based infection control strategies are needed for healthcare workers (HCWs) following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). In this study, we evaluated the negative predictive value (NPV) of a home-based 7-day infection control strategy. Methods: HCWs advised by their infection control or occupational health officer to self-isolate due to a high-risk SARS-CoV-2 exposure were enrolled between May and October 2020. The strategy consisted of symptom-triggered nasopharyngeal SARS-CoV-2 RNA testing from day 0 to day 7 after exposure and standardized home-based nasopharyngeal swab and saliva testing on day 7. The NPV of this strategy was calculated for (1) clinical coronavirus disease 2019 (COVID-19) diagnosis from day 8–14 after exposure, and for (2) asymptomatic SARS-CoV-2 detected by standardized nasopharyngeal swab and saliva specimens collected at days 9, 10, and 14 after exposure. Interim results are reported in the context of a second wave threatening this essential workforce. Results: Among 30 HCWs enrolled, the mean age was 31 years (SD, ±9), and 24 (80%) were female. Moreover, 3 were diagnosed with COVID-19 by day 14 after exposure (secondary attack rate, 10.0%), and all cases were detected using the 7-day infection control strategy: the NPV for subsequent clinical COVID-19 or asymptomatic SARS-CoV-2 detection by day 14 was 100.0% (95% CI, 93.1%–100.0%). Conclusions: Among HCWs with high-risk exposure to SARS-CoV-2, a home-based 7-day infection control strategy may have a high NPV for subsequent COVID-19 and asymptomatic SARS-CoV-2 detection. Ongoing data collection and data sharing are needed to improve the precision of the estimated NPV, and here we report interim results to inform infection control strategies in light of a second wave threatening this essential workforce.

Control Strategies for Semi-Active Lorry Suspensions

1996 ◽  
Vol 210 (2) ◽  
pp. 161-178 ◽  
Author(s):  
D Cebon ◽  
F H Besinger ◽  
D J Cole
Keyword(s):  
Linear Models ◽  
Control Strategies ◽  
Power Input ◽  
Optimum Level ◽  
Passive Damping ◽  
Control Laws ◽  
Body Acceleration ◽  
Performance Improvements ◽  
Full State Feedback ◽  
Active Damper

The optimum level of passive damping for minimizing the root mean square (r.m.s.) dynamic tyre force and r.m.s. body acceleration of a heavy vehicle is determined by testing a damper in a ‘hardware-in-the-loop’ (HiL) test rig. Two different control strategies [‘modified skyhook damping’ (MSD), and linear optimal control with full state feedback (FSF)] are investigated theoretically using linear models, and suspension force control laws are derived. These control laws, along with simple ‘on–off’ control, are then tested experimentally using a prototype semi-active damper which is controlled so as to follow the demanded force, except when power input is required. The achievable performance improvements are compared and differences between the linear theory, computer simulations and experimental performance are discussed. It is found that using FSF control, r.m.s. body acceleration and r.m.s. tyre force can be reduced simultaneously by 28 and 21 per cent of their values for optimal passive damping.

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