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.

Application of Combined Feedforward and Feedback Controller With Shaped Input to Benchmark Problem

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Young Joo Shin ◽  
Peter H. Meckl
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Control Design ◽  
Single Frequency ◽  
Benchmark Problems ◽  
Control Force ◽  
Benchmark Problem ◽  
Advantages And Disadvantages ◽  
Robust Control Design

Benchmark problems have been used to evaluate the performance of a variety of robust control design methodologies by many control engineers over the past 2 decades. A benchmark is a simple but meaningful problem to highlight the advantages and disadvantages of different control strategies. This paper verifies the performance of a new control strategy, which is called combined feedforward and feedback control with shaped input (CFFS), through a benchmark problem applied to a two-mass-spring system. CFFS, which consists of feedback and feedforward controllers and shaped input, can achieve high performance with a simple controller design. This control strategy has several unique characteristics. First, the shaped input is designed to extract energy from the flexible modes, which means that a simpler feedback control design based on a rigid-body model can be used. In addition, only a single frequency must be attenuated to reduce residual vibration of both masses. Second, only the dynamics between control force and the first mass need to be considered in designing both feedback and feedforward controllers. The proposed control strategy is applied to a benchmark problem and its performance is compared with that obtained using two alternative control strategies.

scholarly journals A reward–punishment feedback control strategy based on energy information for wrist rehabilitation

2020 ◽  
Vol 17 (5) ◽  
pp. 172988142094065
Author(s):  
Jiajin Wang ◽  
Jiaji Zhang ◽  
Guokun Zuo ◽  
Changcheng Shi ◽  
Shuai Guo
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Adaptive Controller ◽  
Feedback Mechanism ◽  
Coefficient Of Determination ◽  
Effective Control ◽  
Rehabilitation Robot ◽  
Feedback Control Strategy ◽  
Energy Information

Based on evidence from the previous research in rehabilitation robot control strategies, we found that the common feature of the effective control strategies to promote subjects’ engagement is creating a reward–punishment feedback mechanism. This article proposes a reward–punishment feedback control strategy based on energy information. Firstly, an engagement estimated approach based on energy information is developed to evaluate subjects’ performance. Secondly, the estimated result forms a reward–punishment term, which is introduced into a standard model-based adaptive controller. This modified adaptive controller is capable of giving the reward–punishment feedback to subjects according to their engagement. Finally, several experiments are implemented using a wrist rehabilitation robot to evaluate the proposed control strategy with 10 healthy subjects who have not cardiovascular and cerebrovascular diseases. The results of these experiments show that the mean coefficient of determination ( R 2) of the data obtained by the proposed approach and the classical approach is 0.7988, which illustrate the reliability of the engagement estimated approach based on energy information. And the results also demonstrate that the proposed controller has great potential to promote patients’ engagement for wrist rehabilitation.

scholarly journals Comprehensive Power Flow Analyses and Novel Feedforward Coordination Control Strategy for MMC-Based UPFC

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 824 ◽  
Author(s):  
Jinlian Liu ◽  
Zheng Xu ◽  
Liang Xiao
Keyword(s):  
Power Systems ◽  
Control Strategy ◽  
Computer Aided Design ◽  
Power Flow ◽  
Feedforward Control ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Unified Power Flow Controller ◽  
3 Dimensional ◽  
Steady State Operation

This paper aims to discover the general steady-state operation characteristics, as well as improving the dynamic performance, of the modular multilevel converter (MMC)-based unified power flow controller (UPFC). To achieve this, first, we established a detailed power flow model for MMC-based UPFC containing each critical part and made qualitative and graphical analyses combining 2-dimensional operation planes and 3-dimensional spatial curve surfaces comprehensively to derive general power flow principles and offer necessary references for regulating UPFC. Furthermore, to achieve better performance, we designed a feedforward control strategy for the shunt and series converters of UPFC, both comprising two feedforward control blocks with the introduction of necessary compensating branches, and analyzed the performance in complex and time domain, respectively. The proposed power flow principles and control strategies were validated by a (power systems computer aided design) PSCAD model of 220 kV double-end system; the results reveal the MMC-based UPFC can realize the power flow principles and improve the control speed, stability, and precision of the power flow regulations under various conditions.

A Robust Approach to Dynamic Feedback Linearization for a Steerable Nips Mechanism

2008 ◽  
Author(s):  
Edgar I. Ergueta ◽  
Robert Seifried ◽  
Roberto Horowitz
Keyword(s):  
Control Strategy ◽  
Feedback Linearization ◽  
Position Control ◽  
Control Strategies ◽  
Successful Implementation ◽  
Experimental Setup ◽  
Dynamic Feedback ◽  
Robust Approach ◽  
Internal Loops ◽  
Steerable Nips

This paper presents two different control strategies for paper position control in printing devices. The first strategy is based on feedback linearization plus dynamic extension (dynamic feed-back linearization). Even though this controller is very simple to design, we show that it is not able to handle actuator multiplicative uncertainties, and therefore it fails when it is implemented on the experimental setup. The second strategy we present uses similar concepts, but it is more robust since feedback linearization is used only to linearize the kinematics of the system and internal loops are used to locally control the actuator’s positions and velocities. Not only do we prove the robustness of the second control strategy, but we also show its successful implementation.

scholarly journals Comparison of Feedback Control Strategies for Operation of Granulation Loops

2021 ◽  
Vol 50 (4) ◽  
pp. 736-751
Author(s):  
Ludmila Vesjolaja ◽  
Bjørn Glemmestad ◽  
Bernt Lie
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Fine Particles ◽  
Control Strategies ◽  
Pi Controller ◽  
Oscillatory Behavior ◽  
Double Loop ◽  
Oscillatory Behaviour ◽  
Loop Control ◽  
Median Diameter

Granulation is a particle enlargement process during which fine particles or atomizable liquids are converted into granules via a series of complex granulation mechanisms. In this paper, two feedback control strategies are implemented to make granulation loop processes more steady to operate, i.e., to suppress oscillatory behavior in the produced granule sizes. In the first control strategy, a classical proportional-integral (PI) controller is used, while in the second, a double-loop control strategy is used to control the median diameter of the granules leaving the granulator. The simulation results showed that using the proposed control design for the granulation loop can eliminate the oscillatory behaviour in the produced granule median diameter and make granulation loop processes more steady to operate. A comparison between the two proposed control strategies showed that it is preferable to use the double-loop control strategy.

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.

scholarly journals Integrated Traffic Control for Freeways using Variable Speed Limits and Lane Change Control Actions

2019 ◽  
Vol 2673 (9) ◽  
pp. 602-613 ◽  
Author(s):  
Vasileios Markantonakis ◽  
Dimitrios Ilias Skoufoulas ◽  
Ioannis Papamichail ◽  
Markos Papageorgiou
Keyword(s):  
Control Strategy ◽  
Traffic Control ◽  
Traffic Congestion ◽  
Communication Systems ◽  
Feedforward Control ◽  
Control Strategies ◽  
Connected Vehicles ◽  
Variable Speed ◽  
Speed Limits ◽  
Variable Speed Limits

The wide deployment of vehicle automation and communication systems (VACS) in the next decade is expected to influence traffic performance on freeways. Apart from safety and comfort, one of the goals is the alleviation of traffic congestion which is a major and challenging problem for modern societies. The paper investigates the combined use of two feedback control strategies utilizing VACS at different penetration rates, aiming to maximize throughput at bottleneck locations. The first control strategy employs mainstream traffic flow control using appropriate variable speed limits as an actuator. The second control strategy delivers appropriate lane-changing actions to selected connected vehicles using a feedback-feedforward control law. Investigations of the proposed integrated scheme have been conducted using a microscopic simulation model for a hypothetical freeway featuring a lane-drop bottleneck. The results demonstrate significant improvements even for low penetration rates of connected vehicles.

A dynamic feedback control strategy for control loops with time-varying delay

2013 ◽  
Vol 87 (5) ◽  
pp. 887-897 ◽  
Author(s):  
Behrouz Ebrahimi ◽  
Reza Tafreshi ◽  
Matthew Franchek ◽  
Karolos Grigoriadis ◽  
Javad Mohammadpour
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Time Varying ◽  
Dynamic Feedback ◽  
Control Loops ◽  
Time Varying Delay ◽  
Dynamic Feedback Control ◽  
Feedback Control Strategy ◽  
Varying Delay

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.

Finite-Time Settling Control of a Flexible Arm

1994 ◽  
Vol 208 (2) ◽  
pp. 79-87 ◽  
Author(s):  
S Choura
Keyword(s):  
Control Strategy ◽  
Finite Time ◽  
Position Control ◽  
Feedforward Control ◽  
Control Strategies ◽  
State Space Model ◽  
Control Law ◽  
Flexible Beam ◽  
Flexible Arm ◽  
Finite Set

This paper considers the position control of a flexible beam attached to a rotating rigid hub. The control torque is applied at the hub through a motor. A state-space model describing the motion of the flexible beam is developed and is employed in the design of the control law. The finite-time settling control strategy that combines feedback and feedforward is applied to the beam problem. The feedback part is separately designed to resolve the issues of asymptotic stability and robustness to uncertainties. The feedforward part simultaneously suppresses the rigid-body mode and a finite set of flexible modes at the end of manoeuvre and, therefore, it is the part responsible for the finite-time settling of the beam to its final configuration. It is shown that if the finite-time settling control is compared with previously developed control strategies under the same input bound constraint, it leads to a better suppression of vibrations at the end of manoeuvre, provided that a sufficient number of flexible modes are incorporated in the computation of the feedforward control law. A robustness test is carried out to show the viability of the control strategy supported by computer simulations.

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