Robust Control of Cooperative Adaptive Cruise Control in the Absence of Information About Preceding Vehicle Acceleration
01 Sep 2021-IEEE Transactions on Intelligent Transportation Systems (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 22, Iss: 9, pp 5589-5598
TL;DR: A disturbance observer based sliding mode control is proposed for the control of cooperative adaptive cruise control system, estimating the uncertainty present in the actuator dynamics and the acceleration of preceding vehicle as a lumped disturbance.
Abstract: Cooperative adaptive cruise control (CACC) has a potential to improve traffic throughput, fuel efficiency and vehicle safety. The CACC utilizes onboard sensors and a wireless communication to achieve vehicle stability and string stability of a platoon. The performance of CACC is degraded due to unreliable wireless communication and uncertain dynamics of the vehicle. In this paper, a disturbance observer based sliding mode control is proposed for the control of cooperative adaptive cruise control system. This scheme estimates the uncertainty present in the actuator dynamics and the acceleration of preceding vehicle as a lumped disturbance. The proposed strategy addresses practical issues such as unavailability of preceding vehicle acceleration and range of uncertainty in the vehicle dynamics. The stability of individual vehicles and the string stability of a platoon are derived. The performance of the proposed scheme is verified by considering various traffic scenarios, and it is compared with an existing method.
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TL;DR: In this paper , the longitudinal control of vehicle platoons with a focus on external disturbances, parameter uncertainties, and communication failures is investigated, where a generalized extended state observer is designed to estimate the lumped disturbance and the preceding vehicle's acceleration separately.
Abstract: This paper investigates the longitudinal control of vehicle platoons with a focus on external disturbances, parameter uncertainties, and communication failures. When vehicle platoons encounter vehicle to vehicle wireless communication failures, the preceding vehicle’s acceleration is unavailable, which degrades the performance of the system. However, the existing achievements can not be directly used to address the aforementioned three issues. To this end, a generalized extended state observer-based control (GESOBC) law is contrived. First, the parameter uncertainties and the external disturbances are together regarded as a lumped disturbance. Then, a generalized extended state observer is designed to estimate the lumped disturbance and the preceding vehicle’s acceleration, separately. Based on the estimation, a composite controller consisting of a state feedback control part and an estimation-based feedforward control part is developed. Furthermore, it is proved that the proposed GESOBC method can guarantee the exponentially bounded stability of the individual vehicle and the input to state string stability of the whole vehicle platoon. Finally, numerical simulations are conducted to demonstrate the effectiveness and feasibility of the proposed method.
13 citations
TL;DR: In this paper , a composite FTDO-based super twisting SMC method is developed under zero initial spacing deviations, where the parameter uncertainties, external disturbances, and the preceding vehicle's acceleration are estimated as a lumped disturbance by employing an FTDO.
Abstract: This paper presents a finite time disturbance observer (FTDO)-based super-twisting sliding mode control (SMC) structure for a vehicle platoon system with a focus on parameter uncertainties as well as external disturbances. In order to compensate the parameter uncertainties and external disturbances, a composite FTDO-based super twisting SMC method is developed under zero initial spacing deviations, where the parameter uncertainties, external disturbances, and the preceding vehicle's acceleration are estimated as a lumped disturbance by employing an FTDO. Benefiting from the FTDO, the estimation error dynamics is stable in finite time. Different from the existing SMC-based achievements, the continuity of the control signals can be achieved, which avoids the undesirable chattering phenomenon in the existing SMC-based works. Leveraging an FTDO, the preceding vehicle's acceleration information is not required, which enables the proposed control method to exploit a unidirectional information flow topology. Thus, it can reduce communication burden compared with bidirectional information flow topologies. Then, an improved time gap policy is employed to extend the developed control scheme to a more general case with nonzero initial spacing deviations. In addition, the individual stability of each vehicle is rigorously analyzed by resorting to the Lyapunov stability theory. Furthermore, the strong string stability of the whole vehicle platoon is derived with the help of the Laplace transform. Finally, numerical simulations are conducted to illustrate the effectiveness and applicability of the developed control scheme.
8 citations
01 Aug 2021
TL;DR: This data indicates that string stability analysis is one of key factors to understanding traffic flow dynamics and cooperative adaptive cruise control vehicles are desired to enhance stability of vehicular flo...
Abstract: String stability analysis is one of key factors to understanding traffic flow dynamics. Cooperative adaptive cruise control (CACC) vehicles are desired to enhance stability of vehicular flo...
8 citations
01 Jan 2023
TL;DR: In this article , the longitudinal control of vehicle platoons with a focus on external disturbances, parameter uncertainties, and communication failures is investigated, where a generalized extended state observer is designed to estimate the lumped disturbance and the preceding vehicle's acceleration separately.
Abstract: This paper investigates the longitudinal control of vehicle platoons with a focus on external disturbances, parameter uncertainties, and communication failures. When vehicle platoons encounter vehicle to vehicle wireless communication failures, the preceding vehicle’s acceleration is unavailable, which degrades the performance of the system. However, the existing achievements can not be directly used to address the aforementioned three issues. To this end, a generalized extended state observer-based control (GESOBC) law is contrived. First, the parameter uncertainties and the external disturbances are together regarded as a lumped disturbance. Then, a generalized extended state observer is designed to estimate the lumped disturbance and the preceding vehicle’s acceleration, separately. Based on the estimation, a composite controller consisting of a state feedback control part and an estimation-based feedforward control part is developed. Furthermore, it is proved that the proposed GESOBC method can guarantee the exponentially bounded stability of the individual vehicle and the input to state string stability of the whole vehicle platoon. Finally, numerical simulations are conducted to demonstrate the effectiveness and feasibility of the proposed method.
8 citations
TL;DR: In this article , an online RNN-based finite-time formation tracking control (ORNN-FTFTC) is designed to quickly accomplish an assigned formation of nonlinear generalized and heterogeneous multiagent systems with input fault and saturation.
Abstract: In this article, an online RNN-based finite-time formation tracking control (ORNN-FTFTC) is designed to quickly accomplish an assigned formation of nonlinear generalized and heterogeneous multiagent systems with input fault and saturation. Each agent, including the leader and the followers, can possess different relative degrees and control input numbers but the same output for easy task planning. At least one agent must communicate with the leader and the information of neighborhood agents is required to accomplish the assigned formation task. To fulfill the task under the uncertain environment, the proposed ORNN-FTFTC possesses nonlinear filtering formation error with dynamic fractional exponent, nonlinear filtering gain, and the RNN learning compensation of the aggregately uncertain dynamics in each agent. Not only does the nonlinear filtering gain increase as the nonlinear filtering formation error is in the vicinity of zero to achieve its finite-time convergence, but also the new e-modification learning can cover all the value of formation error such that learning weights are stabilized even in an uncertain environment. Finally, an application to a 3D pose from take-off to a steady-formation of hexa-copter unmanned aerial vehicles and unmanned helicopters with initial formation error certifies the feasibility and robustness of the proposed control.
4 citations
References
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Book•
01 Feb 1992
TL;DR: The theory and practical application of Lyapunov's Theorem, a method for the Study of Non-linear High-Gain Systems, are studied.
Abstract: I. Mathematical Tools.- 1 Scope of the Theory of Sliding Modes.- 1 Shaping the Problem.- 2 Formalization of Sliding Mode Description.- 3 Sliding Modes in Control Systems.- 2 Mathematical Description of Motions on Discontinuity Boundaries.- 1 Regularization Problem.- 2 Equivalent Control Method.- 3 Regularization of Systems Linear with Respect to Control.- 4 Physical Meaning of the Equivalent Control.- 5 Stochastic Regularization.- 3 The Uniqueness Problems.- 1 Examples of Discontinuous Systems with Ambiguous Sliding Equations.- 1.1 Systems with Scalar Control.- 1.2 Systems Nonlinear with Respect to Vector-Valued Control.- 1.3 Example of Ambiguity in a System Linear with Respect to Control ..- 2 Minimal Convex Sets.- 3 Ambiguity in Systems Linear with Respect to Control.- 4 Stability of Sliding Modes.- 1 Problem Statement, Definitions, Necessary Conditions for Stability ..- 2 An Analog of Lyapunov's Theorem to Determine the Sliding Mode Domain.- 3 Piecewise Smooth Lyapunov Functions.- 4 Quadratic Forms Method.- 5 Systems with a Vector-Valued Control Hierarchy.- 6 The Finiteness of Lyapunov Functions in Discontinuous Dynamic Systems.- 5 Singularly Perturbed Discontinuous Systems.- 1 Separation of Motions in Singularly Perturbed Systems.- 2 Problem Statement for Systems with Discontinuous control.- 3 Sliding Modes in Singularly Perturbed Discontinuous Control Systems.- II. Design.- 6 Decoupling in Systems with Discontinuous Controls.- 1 Problem Statement.- 2 Invariant Transformations.- 3 Design Procedure.- 4 Reduction of the Control System Equations to a Regular Form.- 4.1 Single-Input Systems.- 4.2 Multiple-Input Systems.- 7 Eigenvalue Allocation.- 1 Controllability of Stationary Linear Systems.- 2 Canonical Controllability Form.- 3 Eigenvalue Allocation in Linear Systems. Stabilizability.- 4 Design of Discontinuity Surfaces.- 5 Stability of Sliding Modes.- 6 Estimation of Convergence to Sliding Manifold.- 8 Systems with Scalar Control.- 1 Design of Locally Stable Sliding Modes.- 2 Conditions of Sliding Mode Stability "in the Large".- 3 Design Procedure: An Example.- 4 Systems in the Canonical Form.- 9 Dynamic Optimization.- 1 Problem Statement.- 2 Observability, Detectability.- 3 Optimal Control in Linear Systems with Quadratic Criterion.- 4 Optimal Sliding Modes.- 5 Parametric Optimization.- 6 Optimization in Time-Varying Systems.- 10 Control of Linear Plants in the Presence of Disturbances.- 1 Problem Statement.- 2 Sliding Mode Invariance Conditions.- 3 Combined Systems.- 4 Invariant Systems Without Disturbance Measurements.- 5 Eigenvalue Allocation in Invariant System with Non-measurable Disturbances.- 11 Systems with High Gains and Discontinuous Controls.- 1 Decoupled Motion Systems.- 2 Linear Time-Invariant Systems.- 3 Equivalent Control Method for the Study of Non-linear High-Gain Systems.- 4 Concluding Remarks.- 12 Control of Distributed-Parameter Plants.- 1 Systems with Mobile Control.- 2 Design Based on the Lyapunov Method.- 3 Modal Control.- 4 Design of Distributed Control of Multi-Variable Heat Processes.- 13 Control Under Uncertainty Conditions.- 1 Design of Adaptive Systems with Reference Model.- 2 Identification with Piecewise-Continuous Dynamic Models.- 3 Method of Self-Optimization.- 14 State Observation and Filtering.- 1 The Luenberger Observer.- 2 Observer with Discontinuous Parameters.- 3 Sliding Modes in Systems with Asymptotic Observers.- 4 Quasi-Optimal Adaptive Filtering.- 15 Sliding Modes in Problems of Mathematical Programming.- 1 Problem Statement.- 2 Motion Equations and Necessary Existence Conditions for Sliding Mode.- 3 Gradient Procedures for Piecewise Smooth Function.- 4 Conditions for Penalty Function Existence. Convergence of Gradient Procedure.- 5 Design of Piecewise Smooth Penalty Function.- 6 Linearly Independent Constraints.- III. Applications.- 16 Manipulator Control System.- 1 Model of Robot Arm.- 2 Problem Statement.- 3 Design of Control.- 4 Design of Control System for a Two-joint Manipulator.- 5 Manipulator Simulation.- 6 Path Control.- 7 Conclusions.- 17 Sliding Modes in Control of Electric Motors.- 1 Problem Statement.- 2 Control of d. c. Motor.- 3 Control of Induction Motor.- 4 Control of Synchronous Motor.- 18 Examples.- 1 Electric Drives for Metal-cutting Machine Tools.- 2 Vehicle Control.- 3 Process Control.- 4 Other Applications.- References.
5,422 citations
Book•
31 Oct 2005
TL;DR: In this paper, the authors present a mean value model of SI and Diesel engines, and design and analysis of passive and active automotive suspension components, as well as semi-active and active suspensions.
Abstract: 1. Introduction.- 2.Lateral Vehicle Dynamics.- 3. Steering Control For Automated Lane Keeping.- 4. Longitudinal Vehicle Dynamics.- 5. Introduction to Longitudinal Control.- 6. Adaptive Cruise Control.- 7. Longitudinal Control for Vehicle Platoons.- 8. Electronic Stability Control.- 9. Mean Value Modeling Of SI and Diesel Engines.- 10. Design and Analysis of Passive Automotive Suspensions.- 11. Active Automotive Suspensions.-12. Semi-Active Suspensions.- 13. Lateral and Longitudinal Tires Forces.- 14. Tire-Road Friction Measurement on Highway Vehicles.- 15. Roll Dynamics and Rollover Prevention.- 16. Dynamics and Control of Hybrid Gas Electric Vehicles.
3,669 citations
TL;DR: It turns out that the deviation of the system from its prescribed constraints (sliding accuracy) is proportional to the switching time delay and a new class of sliding modes and algorithms is presented and the concept of sliding mode order is introduced.
Abstract: The synthesis of a control algorithm that stirs a nonlinear system to a given manifold and keeps it within this constraint is considered. Usually, what is called sliding mode is employed in such synthesis. This sliding mode is characterized, in practice, by a high-frequency switching of the control. It turns out that the deviation of the system from its prescribed constraints (sliding accuracy) is proportional to the switching time delay. A new class of sliding modes and algorithms is presented and the concept of sliding mode order is introduced. These algorithms feature a bounded control continuously depending on time, with discontinuities only in the control derivative. It is also shown that the sliding accuracy is proportional to the square of the switching time delay.
2,714 citations
Book•
01 Jan 1999
TL;DR: Sliding mode control (SMC) is gaining increasing importance as a universal design tool for the robust control of linear and nonlinear systems as mentioned in this paper, and is particularly useful for electro-mechanical systems because of its discontinuous structure.
Abstract: Sliding Mode Control (SMC) is gaining increasing importance as a universal design tool for the robust control of linear and nonlinear systems. The strengths of sliding mode controllers result from the ease and flexibility of the methodology for their design and implementation. They provide inherent order reduction, direct incorporation of robustness against system uncertainties and disturbances, and an implicit stability proof. They also allow for the design of high performance control systems at low costs. SMC is particularly useful for electro-mechanical systems because of its discontinuous structure. In fact, since the hardware of many electro-mechanical systems (such as electric motors) prescribes discontinuous inputs, SMC has become the natural choice for direct implementation. The book is intended primarily for engineers and establishes an interdisciplinary bridge between control science, electrical and mechanical engineering.
2,593 citations
TL;DR: This survey gives a systematic and comprehensive tutorial and summary on the existing disturbance/uncertainty estimation and attenuation techniques, most notably, DOBC, active disturbance rejection control, disturbance accommodation control, and composite hierarchical antidisturbance control.
Abstract: Disturbance-observer-based control (DOBC) and related methods have been researched and applied in various industrial sectors in the last four decades. This survey, at first time, gives a systematic and comprehensive tutorial and summary on the existing disturbance/uncertainty estimation and attenuation techniques, most notably, DOBC, active disturbance rejection control, disturbance accommodation control, and composite hierarchical antidisturbance control. In all of these methods, disturbance and uncertainty are, in general, lumped together, and an observation mechanism is employed to estimate the total disturbance. This paper first reviews a number of widely used linear and nonlinear disturbance/uncertainty estimation techniques and then discusses and compares various compensation techniques and the procedures of integrating disturbance/uncertainty compensation with a (predesigned) linear/nonlinear controller. It also provides concise tutorials of the main methods in this area with clear descriptions of their features. The application of this group of methods in various industrial sections is reviewed, with emphasis on the commercialization of some algorithms. The survey is ended with the discussion of future directions.
1,849 citations